Table of Content

28 April 2023, Volume 27 Issue 12 Previous Issue    Next Issue

For Selected:

Download Citations EndNote Reference Manager ProCite BibTeX RefWorks

Toggle Thumbnails

Select

Properties of force growth factor E peptide bionic bone matrix with polyethylene glycol derivative hydrogel as a carrier Peng Kun 2023, 27 (12):  1811-1816.  doi: 10.12307/2023.135 Abstract ( 490 )   PDF (1101KB) ( 104 )   Save BACKGROUND: Bone repair materials with biological functions have always been a research focus in biomedical engineering. OBJECTIVE: To develop bionic bone matrix material with bionic space structure and bionic function based on the requirements of molecular structure biomimetic and biological function biomimetic.  METHODS: Using amino-terminated polyethylene glycol and pyromellitic anhydride as reactants, four kinds of polyethylene glycol derivative hydrogels were obtained by adjusting the amount of butanediamine added (15, 30, 45, 60 µL). Bioactive substances based on polylactic acid and force growth factor (MGF-Ct24E-MPLA-EG-g-HAP) were added to the four hydrogels separately. The solvent method was used to prepare bioactive biomimetic bone matrix material (PAPI-BDA/MGF-Ct24E-MPLA-EG-g-HAP). The bioactive material loading rate, porosity, surface morphology, hydrophilic/hydrophobic properties, water absorption and microscopic morphology of the bioactive bionic bone matrix materials were characterized. RESULTS AND CONCLUSION: (1) In the production process of the bionic bone matrix material, in PBS with pH=5.8, with the increased amount of butanediamine added, the loading of bioactive substances in the bionic bone matrix material first increased and then decreased. The loading of bioactive substances was the highest when the amount was 30 µL; in PBS with pH=3.5-7.4, the loading of bioactive substances in the biomimetic bone matrix material (the addition amount of butanediamine was 30 µL) showed a decreasing trend. When the pH value increased to 9.8, the loading of bioactive substances in the bionic bone matrix material remained basically stable. (2) In PBS with the same pH value, the porosity of the bionic bone matrix material decreased with the increase of the addition amount of butanediamine. When the addition amount of butanediamine was the same, with the increase of the pH value of PBS, the porosity of the bionic bone matrix material first decreased and then increased. (3) In PBS with pH=5.8, with the increase of the addition of butanediamine, the static contact angle of the bionic bone matrix material decreased and the water absorption increased. (4) It can be seen under the scanning electron microscope, the bionic bone matrix material has a continuous open pore structure, the pores are interconnected, the pore size distribution is 230-690 nm, and the pore size is inversely related to the amount of butanediamine added. The bionic bone matrix material prepared by adding butanediamine in an amount of 30 µL is similar to the structure of natural bone matrix.   Figures and Tables | References | Related Articles | Metrics

Select

Rat bone defect repaired with polytrimethylene carbonate/beta-tricalcium phosphate microsphere scaffold Huang Yanni, Yang Hua, Yang Dongmei, Hu Xulin, Gao Hong, Huang Yina 2023, 27 (12):  1856-1862.  doi: 10.12307/2023.102 Abstract ( 614 )   PDF (3920KB) ( 143 )   Save BACKGROUND: At present, it is difficult for a single scaffold material to meet the needs of osteogenesis in bone tissue engineering. Microsphere scaffolds combined with a variety of materials can maximize their strengths and avoid their weaknesses, which has great application potential. OBJECTIVE: To explore the biocompatibility, degradability, and osteoinductivity of a new type of polytrimethylene carbonate/β-tricalcium phosphate in animals.  METHODS: The β-tricalcium phosphate bone cement and polytrimethylene carbonate/β-tricalcium phosphate microsphere scaffold were prepared. Eighteen male SD rats were randomly divided into three groups (n=6) according to their weight. No material was implanted in the bilateral femoral defects in the blank control group. The β-tricalcium phosphate bone cement was implanted in the bilateral femoral defects in the control group. Polytrimethylene carbonate/β-tricalcium phosphate microsphere scaffold was implanted at bilateral femoral defects in the experimental group. At 4, 8, and 12 weeks after operation, the bilateral femurs were taken out for hematoxylin-eosin staining, Masson staining, and immunohistochemical staining for osteocalcin.  RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining and Masson staining: At 4 weeks after operation, the bone defect in the blank control group was surrounded by fibrous tissue and numerous inflammatory cells gathered. In the control group, the material was mostly degraded and surrounded by fibrous tissue, with a small amount of new bone matrix and bone trabecular formation at the edge of the material, which was surrounded by a few inflammatory cells. The material in the experimental group did not degrade remarkably and was surrounded by fibrous tissue. Some new bone matrix and bone trabecular formation were detected at the edge of the material, which was surrounded by a few inflammatory cells. At 12 weeks postoperatively, the blank control group presented regular trabecular bone, which was connected to each other, without inflammatory cells. In the control group, the material was completely degraded and trabecular bone was regular, forming a thick lamellar shape, without inflammatory cells. In the experimental group, materials were partially degraded; bone mass was increased and dense, with the absence of inflammatory cells. (2) Immunohistochemical staining: With prolonged time, the expression of osteocalcin in the bone defect of the control group increased first and then decreased. The expression of osteocalcin in the blank control group and the experimental group showed a gradually increasing trend. The expression of osteocalcin at each time point was higher in the control and experimental groups than that of the blank control group (P < 0.05). The expression of osteocalcin in the experimental group was higher than that of the control group at 12 weeks postoperatively (P < 0.05). (3) These findings exhibit that the polytrimethylene carbonate/β-tricalcium phosphate microsphere scaffold has good biocompatibility, osteoinductivity, and moderate biodegradability.  Figures and Tables | References | Related Articles | Metrics

Select

Effects of quercetin sustained release system on osteogenic properties of MC3T3-E1 cells Ma Ziyu, Zhang Bin, Zhang Yuntao, Liu Xiaolin, Bian Zhihong, Qiao Luhui, Hou Yudong 2023, 27 (12):  1870-1876.  doi: 10.12307/2023.017 Abstract ( 758 )   PDF (1355KB) ( 130 )   Save BACKGROUND: Quercetin plays a significant role in promoting osteogenesis, anti-allergy, anti-inflammatory, anti-oxidation, anti-virus, lowering blood pressure, and anti-platelet aggregation, but its stability and solubility are poor, which is not conducive to the exertion and application of its efficacy.   OBJECTIVE: To prepare quercetin sustained-release nanofibers for promoting bone formation and to investigate in vitro release mechanism of quercetin sustained-release nanofibers and its effect on the osteogenic properties of MC3T3-E1 cells. METHODS: Quercetin, bovine serum albumin, and chitosan were used as materials. The quercetin sustained-release nanofibers coated with chitosan were prepared by improved solvent removal method and electrospinning technology. The quercetin sustained-release nanofibers, polycaprolactone, and polyethylene glycol were utilized as materials. The quercetin sustained-release nanofiber scaffolds were prepared using electrospinning to characterize microscopic morphology, water contact angle, and in vitro drug release of nanofibers. Polycaprolactone/polyethylene glycol nanofiber scaffolds and quercetin sustained-release nanofibers were cocultured with MC3T3-E1 cells. The cells cultured alone were taken as blank controls. The proliferation and osteogenic differentiation abilities of the three groups were detected. RESULTS AND CONCLUSION: (1) Transmission electron microscopy showed that quercetin sustained-release nanospheres had smooth surface and uniform diameter. The microspheres could be effectively spun into the electrospinning scaffold. Scanning electron microscopy showed that the quercetin sustained-release nanospheres were regular spheres. The nanofibers were irregularly interwoven into a network structure and formed pores of different sizes without obvious fracture. (2) The contact angle experiment showed that the water contact angle of quercetin sustained-release nanofiber group was significantly smaller than that of polycaprolactone group and polycaprolactone/polyethylene glycol group. (3) The drug content released in the first 4 days reached about 30% in the quercetin sustained-release nanofiber group. The drug release time could be maintained for about one month, and the release amount could reach 70% of the drug content. (4) Compared with the blank control group, polycaprolactone/polyethylene glycol nanofibers and quercetin sustained-release nanofibers could promote MC3T3-E1 cell proliferation, alkaline phosphatase expression, and calcium deposition. (5) It is concluded that quercetin sustained-release nanofibers have a good controlled drug release effect and can promote the proliferation and osteogenic differentiation of MC3T3-E1 cells.  Figures and Tables | References | Related Articles | Metrics

Select

Curcumin loaded injectable microspheres retard progression of intervertebral disc degeneration Ye Xuwen, Gu Yong, Chen Liang 2023, 27 (12):  1884-1891.  doi: 10.12307/2023.043 Abstract ( 716 )   PDF (1742KB) ( 212 )   Save BACKGROUND: The mechanism of intervertebral disc degeneration is complicated. The activation of inflammatory pathways, the proliferation of inflammatory factors, and the excessive accumulation of reactive oxygen species can all accelerate the process of intervertebral disc degeneration. Curcumin is a natural drug extracted from traditional Chinese medicine curcuma, which has pharmacological effects such as inhibiting inflammation, antioxidant stress and so on.  OBJECTIVE: To study the curative effect of local injection of curcumin loaded sustained-release microspheres on intervertebral disc degeneration in rats. METHODS: (1) Sustained release microspheres loaded with curcumin nanoparticles were prepared by microfluidic technology. The drug release and degradation were evaluated in vitro. (2) Sustained-release microspheres and unloaded microspheres were co-cultured with nucleus pulposus cells in vitro. Cells cultured alone were used as controls. The three groups of cells were cultured in normal environment and oxidative stress environment (adding H2O2). The activity and proliferation of nucleus pulposus cells were evaluated by CCK-8 assay and live/dead staining. The expression levels of related factors were analyzed by qRT-PCR. (3) A total of 30 SD rats were randomly divided into normal group, degeneration group, unloaded microsphere group, curcumin group and sustained-release microsphere group (n=6 per group). The models of intervertebral disc degeneration were established by percutaneous puncture in the 7-8 and 8-9 segments of the caudal vertebra of the rats. The corresponding solutions were injected into the degenerated intervertebral discs in the unloaded microsphere group, the curcumin group, and the sustained-release microsphere group. After 4 weeks, the changes of intervertebral disc tissue structure were observed by imaging and histology.  RESULTS AND CONCLUSION: (1) The sustained-release microspheres could slowly and continuously release curcumin, and the total amount of curcumin released was (84.11±2.71)% at 28 days. In PBS containing collagenase, the mass of the sustained-release microspheres gradually decreased and disappeared at the 5th week. (2) The results of CCK-8 assay and live/dead staining indicated that the sustained-release microspheres did not reduce the proliferation ability of nucleus pulposus cells under normal conditions and could maintain the proliferation activity of nucleus pulposus cells under oxidative stress compared with unloaded microspheres. qRT-PCR experiments indicated that compared with the normal environment, the oxidative stress environment activated the overexpression of mRNA of various inflammatory factors in nucleus pulposus cells. Under oxidative stress, the mRNA expression levels of tumor necrosis factor-α, interleukin-1β, interleukin-6 and matrix metalloproteinase 3 in the sustained-release microsphere group were decreased and mRNA expression of type II collagen and proteoglycan was increased compared with the unloaded microsphere group and the control group. (3) The results of animal in vivo experiments showed that the imaging and histological evaluation of the unloaded microsphere group was not significantly different from that of the degeneration group after 4 weeks. The intervertebral space height and MRI score of the curcumin group were improved to a certain extent compared with the degeneration group and the unloaded microsphere group at 1 week, but the imaging and histological evaluations at 4 weeks were not as good as those of the sustained-release microsphere group. (4) In conclusion, curcumin sustained-release microspheres could inhibit the apoptosis of nucleus pulposus cells induced by H2O2 and retard the progression of intervertebral disc degeneration. Its mechanism is associated with inhibiting the nuclear factor κB pathway and reducing the level of oxidative stress.  Figures and Tables | References | Related Articles | Metrics

Select

Calcined antler cancellous bone/collagen composite scaffolds promote bone defect repair Zhou Yingying, Zhang Xuehui 2023, 27 (12):  1938-1943.  doi: 10.12307/2023.037 Abstract ( 545 )   PDF (1980KB) ( 773 )   Save BACKGROUND: The shapable bone filling materials currently used in clinic are mainly composite materials composed with xenogeneic bone derived from calf bone and collagen. However, there is an animal ethical controversy because its inorganic ingredients are derived from slaughtered calves. It is necessary to find a safe, effective and shapable bone scaffold material, which not only can avoid ethical problems but also has excellent osteogenic properties. OBJECTIVE: To prepare composite scaffolds with excellent plasticity and ability in repairing bone by chemically cross-linking collagen with granules of calcined antler cancellous bone.  METHODS: Calcined antler cancellous bone granules were prepared by defatted and deproteinized process and combined with calcination after removal of the antler cortical bone. Calcined antler cancellous bone/type I collagen composite scaffolds were fabricated with the 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide/N-Hydroxysuccinimide cross-linking method. In 10 adult Sprague-Dawley rats, a 5-mm sized full-thick bone defect was prepared on both sides of the sagittal suture of the skulls. Bio-Oss/Collagen® composite scaffolds were implanted into the defect on the left side (control group) and calcined antler cancellous bone/collagen composite scaffolds were implanted into the defect on the right side (experimental group). Hematoxylin-eosin staining and Masson’s trichrome staining were performed in skull specimens at 4 and 12 weeks after the implant operation.  RESULTS AND CONCLUSION: (1) Four weeks after the operation, hematoxylin-eosin staining showed that new bone was formed in the bone defects in both groups, but not completely healed. Osteoblasts were seen around the implanted materials, and there were more osteoblasts around the materials in the experimental group. Masson’s trichrome staining showed that there were new collagen fibers arranged regularly and irregular bone marrow cavity around the materials of the two groups. (2) At 12 weeks after the operation, hematoxylin-eosin staining showed that the bone defects healed well in both groups; the edge of the defect was completely fused with the new bone; and the residual material was surrounded by the new bone. The new bone structure in the experimental group was dense and the degree of remodeling was high. (3) To conclude, our findings revealed that the calcined antler cancellous bone/collagen composite scaffolds are provided with good plasticity, osteoconductivity, histocompatibility and excellent bone repair effect, and can be used as a potential shapable bone filling scaffold material. Figures and Tables | References | Related Articles | Metrics

Select

Characterization and photothermal effect of indocyanine green encapsulated poly lactic acid-co-glycolic acid microspheres Fan Yaru, Li Ruixin, Li Fengji, Luo Rui, Liu Hao, Yan Yingbin 2023, 27 (12):  1817-1823.  doi: 10.12307/2023.032 Abstract ( 724 )   PDF (1875KB) ( 118 )   Save BACKGROUND: Indocyanine green, an efficient photothermal conversion agent, can be used for photothermal therapy of oral squamous cell carcinoma, but it has some shortcomings such as water instability and photodegradation. Using a carrier to encapsulate indocyanine green to improve its stability was of great significance for exploring photothermal therapy of oral squamous cell carcinoma.   OBJECTIVE: Indocyanine green encapsulated poly lactic acid-co-glycolic acid microspheres were fabricated to delay the photodegradation of indocyanine green and improve its photothermal stability.  METHODS: (1) The indocyanine green encapsulated poly lactic acid-co-glycolic acid microspheres were prepared by emulsion-solvent evaporation method. The morphology, particle size distribution, surface charge, drug loading and encapsulation efficiency were characterized. (2) The free indocyanine green solution and the indocyanine green microsphere suspension were irradiated with near-infrared light at different mass concentrations (0.6, 0.8, 1.0, 1.2 g/L) for 5 minutes to investigate the temperature changes of the solutions. The free indocyanine green solution and the indocyanine green microsphere suspension were exposed to natural light for 0, 3, 6, and 9 days at a mass concentration of 1.0 g/L to observe the temperature changes within 5 minutes of near-infrared light irradiation. The free indocyanine green solution and the indocyanine green microsphere suspension were subjected to four on-off laser irradiation cycles at a mass concentration of 1.0 g/L to investigate the temperature changes of the solutions. (3) The tongue squamous cell carcinoma cell line SCC-25 was inoculated in a 48-well plate and cultured in eight groups: control group, blank microsphere group, 1.0 g/L free indocyanine green group, 1.0 g/L indocyanine green microsphere group, near-infrared light group, blank microsphere+near-infrared light group, 1.0 g/L free indocyanine green+near-infrared light group, and 1.0 g/L indocyanine green microsphere+near-infrared light group. After 12 hours of treatment, cell viability was detected by CCK-8 assay.   RESULTS AND CONCLUSION: (1) The indocyanine green microspheres had smooth surfaces with particle sizes of (2.54±0.29) μm and zeta potential of −(20.2±1.58) mV. Encapsulation efficiency and loading efficiency were (69.24±1.29)% and (4.87±0.15)%, respectively. (2) Free indocyanine green and indocyanine green microspheres had similar photothermal conversion ability, but after increasing the number of laser irradiation or storage without light, the photothermal conversion ability of free indocyanine green obviously decreased compared with indocyanine green microspheres. (3) The SCC-25 cells in the 1.0 g/L free indocyanine green+near-infrared light group and the 1.0 g/L indocyanine green microsphere+near-infrared light group shrank to a spherical shape, and the cell viability of the two groups was lower than that of the control group (P < 0.001). (4) Indocyanine green microspheres possess efficient photothermal conversion ability and can obviously delay photobleaching and photodegradation of indocyanine green.  Figures and Tables | References | Related Articles | Metrics

Select

Biomimetic microenvironment constructed from gelatin methacrylamide/platelet-rich plasma hydrogel promotes the function of insulinoma cell line MIN6 in mice Zhu Biwen, Wang Dongzhi, Wu Di, Gong Tiancheng, Pan Haopeng, Lu Yuhua, Guo Yibing, Wang Zhiwei, Huang Yan 2023, 27 (12):  1824-1831.  doi: 10.12307/2023.082 Abstract ( 809 )   PDF (1771KB) ( 882 )   Save BACKGROUND: In the field of pancreatic tissue engineering, constructing biomimetic microenvironment to promote the survival and functional exertion of insulin-secreting cells remains difficult point and hot problem. OBJECTIVE: To construct a biomimetic microenvironment based on gelatin methacrylamide/platelet-rich plasma hydrogel to promote the survival and cellular functional of MIN6.  METHODS: 10%, 30% and 50% platelet-rich plasmas were mixed with 50 g/L final concentration of gelatin methacrylamide, gelation by the activation of Ca2+/thrombin and ultraviolet irradiation (abbreviated as G+10P, G+30P, G+50P). Simultaneously, pure gelatin methacrylamide hydrogel was prepared (denoted as G). The porosity, Young’s modulus, swelling properties and rheological behavior of hydrogels of the four groups were tested. MIN6 cells were seeded on the gel surface, and cell morphology and proliferation were detected, followed by qRT-PCR, immunofluorescence and release assays of insulin.  RESULTS AND CONCLUSION: (1) The porosity of the composite-component hydrogel was smaller than that of the single-component hydrogel, and the Young's modulus was higher than that of the single-component hydrogel. Furthermore, the porosity and Young's modulus of the composite hydrogel decreased with the increase of the platelet-rich plasma concentration. The swelling rate of the G+30P and G+50P groups was lower than that of the G and G+10P groups  (P < 0.05). The storage modulus and dissipation modulus of the composite hydrogels were higher than those of the single-component hydrogels (P < 0.05). (2) Under the light microscope, the cells on the surface of the monocomponent hydrogel were clumpy and scattered; the cells on the surface of the composite-component hydrogel were clumps, but grew faster and the cell clusters were tightly connected. Live-dead staining showed that the hydrogels in each group could promote cell survival; the number of dead cells in G+30P and G+50P groups was significantly less than that in G+10P and G groups. The CCK-8 assay displayed that the composite-component hydrogel had a stronger promoting effect on cell proliferation than the monocomponent hydrogel. Moreover, with the increase of platelet-rich plasma concentration, the promoting effect on proliferation was more obvious. (3) qRT-PCR demonstrated that compared with the monocomponent hydrogel, the composite-component hydrogel could significantly up-regulate the mRNA expression levels of islet-duodenum homeobox 1, insulin, and glucokinase; among them, the G+30P group was the most obvious. Immunofluorescence and insulin release assays exhibited that compared with monocomponent hydrogels, composite-component hydrogels could promote insulin protein expression and insulin release. (4) The results confirm that the gelatin methacrylamide/platelet-rich plasma hydrogel can be used to simulate the microenvironment of insulin-secreting cells and can significantly improve their survivals and functions.   Figures and Tables | References | Related Articles | Metrics

Select

Effects of Sanhuang gel on wound healing, basic fibroblast growth factor and interleukin 17 levels of auricular skin defect in rabbits Ma Hongfeng, Ren Qing, Cheng Wanmin, Wang Jiguo, Meng Qingyan 2023, 27 (12):  1842-1847.  doi: 10.12307/2023.039 Abstract ( 472 )   PDF (1355KB) ( 119 )   Save BACKGROUND: Due to the particularity of the ear structure, the skin at the auricle injury usually has poor motion range and tissue regeneration ability, and it is difficult to heal. Therefore, how to accelerate the wound healing and obtain an ideal repair effect has always been a problem and research hotspot in the field of surgery. OBJECTIVE: To explore the effects of Sanhuang gel on the wound healing, basic fibroblast growth factor and interleukin 17 levels of auricle skin defect in rabbits.  METHODS: Sixty male New Zealand rabbits were randomly divided into six groups (n=10 per group). In group A, no treatment was given. In groups B-F, a circular skin defect area with the diameter of 1 cm was made in the auricle. In group B, the wound was injected with physiological saline. In group C, the wound was coated with asiaticoside cream ointment. In group D, the wound was coated with Sanhuang gel. In group E, the wound was injected with PI3K/AKT agonist 740 Y-P. In group F, the wound was coated with Sanhuang gel and injected with 740 Y-P. The treatment was performed twice a day, for 30 consecutive days. The wound healing of rabbit ear was observed and recorded, and the pathological morphology of ear tissue was detected by hematoxylin-eosin staining. The mRNA relative expression levels of basic fibroblast growth factor and interleukin 17 in rabbit ear tissue were detected by real-time PCR. The protein expression of PI3K/AKT pathway in rabbit ear tissue was detected by western blot assay.  RESULTS AND CONCLUSION: (1) After treatment, the skin wound healing speed was accelerated. After 30 days of treatment, the wound healing rate of Sanhuang gel and PI3K/AKT agonist alone was higher than that of asiaticoside cream ointment, and the combined application of the two had the highest wound healing rate. (2) Hematoxylin-eosin staining results showed that the epidermis of group B was significantly thickened and blood vessels were dilated; and a large number of infiltrated inflammatory cells and fibrous tissue hyperplasia were seen. Compared with group B, the morphology of groups C, D, E, and F was significantly improved, and new capillaries and numerous proliferated fibroblasts and endothelial cells were seen. Among them, group F had the most obvious improvement. (3) RT-PCR detection showed that the relative expression of basic fibroblast growth factor mRNA decreased and the relative expression of interleukin 17 mRNA increased after auricular skin injury. After different treatments, the relative mRNA expression of the two factors was improved to varying degrees. The improvement effect of Sanhuang gel and PI3K/AKT agonist alone was stronger than that of asiaticoside cream ointment, and the improvement effect of their combination was strongest. (4) Western blot assay showed that the expression of PI3K, AKT, p-PI3K, and p-AKT proteins decreased after auricular skin injury. The expression levels of the four proteins increased to varying degrees after different treatments. The elevating effect of Sanhuang gel and PI3K/AKT agonist alone was stronger than that of asiaticoside cream ointment, and the elevating effect of their combination was strongest. (5) The results show that Sanhuang gel can promote the wound healing of auricular skin defects, and its mechanism may be associated with the activation of PI3K/AKT pathway.   Figures and Tables | References | Related Articles | Metrics

Select

Establishment of a drug release model of leuprorelin acetate implant in vitro and release kinetic behavior and thermodynamic characteristics Zhu Boru, Tang Hai, Sun Jiahui, Wang Xiaowen, Li Puchao, Liu Quanli 2023, 27 (12):  1892-1899.  doi: 10.12307/2023.008 Abstract ( 735 )   PDF (1507KB) ( 778 )   Save BACKGROUND: At present, China has not made clear guidance on the in vitro dissolution of subcutaneous preparations. Because the release cycle of slow-release and controlled-release preparations with poly(lactic-co-glycolic acid) copolymer as carrier is generally long, it is very important to develop an in vitro release method that can better simulate in vivo absorption.  OBJECTIVE: To prepare leuprorelin acetate subcutaneous implant, develop an in vitro release method with good correlation with in vivo, establish an in vitro accelerated release model, investigate the correlation between drug release kinetics and thermodynamics, and elaborate the release mechanism.  METHODS: Poly(lactic-co-glycolic acid) was used as a carrier. Leuprolide acetate implants were synthesized by hot-melt extrusion technology, and its physicochemical properties were characterized during the molding process. According to the developed in vitro drug release method, the in vitro drug release test was carried out. Taking the release degree as the index, the formulation with a release cycle of 1 month was screened. Adult male SD rats were used as animal models and subcutaneously implanted with leuprolide acetate implants with a release cycle of 1 month. Blood was obtained from the orbit at the set time point. The concentration of leuprorelin in plasma was determined by liquid chromatography-tandem mass spectrometry to analyze the correlation between in vivo and in vitro drug release. The leuprolide acetate implant was taken with a release cycle of 1 month. The in vitro accelerated test was carried out with temperature as a single variable to fit the release kinetic equation. Simultaneously, the microscopic morphology of the implants was observed under scanning electron microscope.  RESULTS AND CONCLUSION: (1) The experiment set up five kinds of implants. The in vitro drug release experiment demonstrated that the release cycle of the 5th formula implant (the feeding ratio of leuprolide acetate was 25%; the feeding ratio of the carrier was 75%; and the mass ratio of poly(lactic-co-glycolic acid) copolymer with molecular mass of 10 kD and 30 kD in the carrier was 1:1) was 30 days, which met the requirements and was used for subsequent experiments. (2) The established in vitro release method had good correlation with drug release in vivo (y=0.945x-5.586 18, R2=0.945 4). (3) The cumulative release curve in vitro accorded with the S-type three-phase model: sudden release period, hysteresis period, and zero order rapid release period. In the process of heating up, based on the zero order drug release rate of 312.15 K, the thermodynamic and drug release kinetic rates accorded with the equation r=7.768 25E-30×e(4.787 45)+0.883 03. (4) The results show that the developed in vitro release method can better describe the dynamic information of drug release in vivo. The in vitro release curve is S-shaped. The release mechanism is the combination of diffusion and dissolution, and the drug release kinetics and thermodynamics in the zero order rapid release period are exponential.  Figures and Tables | References | Related Articles | Metrics

Select

3D extracellular matrix hydrogel loaded with exosomes promotes wound repair Ling Huajun, Cui Ruiwen, Wang Qiyou 2023, 27 (12):  1900-1905.  doi: 10.12307/2023.018 Abstract ( 796 )   PDF (1929KB) ( 349 )   Save BACKGROUND: The application of extracellular matrix hydrogels can effectively deliver exosomes and bridge with the surrounding tissues of the skin, which is helpful for the repair of skin damage.  OBJECTIVE: To explore the effect of 3D gelatin extracellular matrix hydrogel loaded with bone marrow mesenchymal stem cells-derived exosomes on skin wounds.  METHODS: Exosomes of the supernatant of rat bone marrow mesenchymal cells were obtained by ultracentrifugation. (1) A methacrylic acid-modified gelatin hydrogel was prepared, and exosomes and photoinitiators were added to cross-link under ultraviolet light to form a 3D gelatin extracellular matrix hydrogel loaded with exosomes. (2) The fibroblasts were seeded on the exosome-loaded 3D gelatin extracellular matrix hydrogel and ordinary culture plates, respectively. After 12 hours of seeding, the cell migration was observed by scratch experiment. (3) A skin injury wound with a diameter of 1 cm and a depth of 0.2 cm was made on the back of 20 adult SD rats. The experimental group (n=10) was covered with 3D extracellular matrix hydrogel loaded with exosomes, and the control group (n=10) was covered with normal saline, and finally with sterile gauze. Two weeks after operation, the structural changes and collagen deposition of the wound were observed by hematoxylin-eosin staining and Masson staining.  RESULTS AND CONCLUSION: (1) The scratch experiment exhibited that the migration ability of fibroblasts on the exosome-loaded 3D gelatin extracellular matrix hydrogel was stronger than that of the ordinary culture plate. (2) Hematoxylin-eosin staining in the animal experiment displayed that skin tissue structure of the control group was broken to varying degrees, and the number of inflammatory cells increased. The skin tissue structure of the experimental group was relatively complete, the number of cells increased obviously, and the microvascular structure was clearly visible and the density increased. (3) Masson staining in animal experiment demonstrated that the skin tissue of the experimental group contained a large number of regularly arranged collagen fibers. There were only a few collagen fibers in the control group, and the structure was sparse. (4) It is concluded that 3D extracellular matrix-based hydrogel loaded with bone marrow mesenchymal stem cells-derived exosomes can be conducive to wound repair. It may be related to the promotion of fibroblast migration by exosomes. Figures and Tables | References | Related Articles | Metrics

Select

Effect of copper sulfide nanoparticles loaded thermosensitive hydrogel Pluronic F127 on infected wound healing in rats Hu Jinlong, Quan Huahong, Wang Jingcheng, Zhang Pei, Zhang Jiale, Chen Pengtao, Liang Yuan 2023, 27 (12):  1927-1931.  doi: 10.12307/2023.004 Abstract ( 1157 )   PDF (2208KB) ( 208 )   Save BACKGROUND: Copper sulfide nanoparticles have good antibacterial and wound healing effects, but they are not easy to persist in wounds, which limits their application to a certain extent. OBJECTIVE: To investigate the effect of copper sulfide nanoparticles loaded thermosensitive hydrogel Pluronic F127 on infected wound healing in rats.  METHODS: Copper sulfide nanoparticles, thermosensitive hydrogel Pluronic F127, and copper sulfide nanoparticles loaded Pluronic F127 were prepared respectively. Twenty-four male Wistar rats were taken to establish a wound model of Staphylococcus aureus on the back. One day later, they were randomly divided into three groups (n=8). In the control group, the wounds were injected with PBS. In the hydrogel group, the wounds were covered with thermosensitive hydrogel pluronic F127. In the nanoparticle group, the wounds were covered with copper sulfide nanoparticles loaded with thermosensitive hydrogel Pluronic F127. On day 3 after wound treatment, the bacteriological test of the wound was performed. On day 14 after wound treatment, the wound area was measured; blood was collected to test the liver and kidney functions of the rats and the histological changes of the wound and main organs were observed. RESULTS AND CONCLUSION: (1) On day 3 of wound treatment, the number of colonies in the wound tissue was significantly lower in the nanoparticle group than that of the control and hydrogel groups (P < 0.05). (2) On day 14 of wound treatment, the wound area of the rats was smaller in the nanoparticle group than that in the control and hydrogel groups (P < 0.05). (3) On  day 14 of wound treatment, hematoxylin-eosin staining of wound tissue displayed that relatively dense and mature granulation tissue was seen in the nanoparticle group, while a large number of loose and immature granulation tissues were seen in the control and hydrogel groups. Masson staining exhibited that loose collagen tissue was seen in the control and hydrogel groups, and dense collagen tissue was seen in the nanoparticle group. (4) There was no significant difference in liver and kidney function index values among the three groups (P > 0.05). No obvious histopathological changes were found in the main organs such as heart, liver, spleen, lung, and kidney. (5) Pluronic F127 hydrogel loaded copper sulfide nanoparticles could obviously inhibit the growth of bacteria and promote the healing of infectious wounds. Figures and Tables | References | Related Articles | Metrics

Select

Finite element analysis of maxillary defect reconstruction based on polyetheretherketone meshes Li Xiaoxue, Hou Xiaowei 2023, 27 (12):  1805-1810.  doi: 10.12307/2023.075 Abstract ( 461 )   PDF (2441KB) ( 279 )   Save BACKGROUND: The elastic modulus of polyetheretherketone is close to that of bone tissue, so it can be used as a good orthopedic implant material for repairing jaw bone defects.  OBJECTIVE: To establish the digital models of personalized polyetheretherketone scaffolds with different thicknesses and apertures to analyze Von Mises stress and Von Mises strain distribution by finite element analysis.  METHODS: Jaw cone beam CT data from a patient with maxillary right central incisor tooth loss and maxilla defects were used to establish this digital model. A three-dimensional model of right maxilla defect was reconstructed firstly by mirror image of the contralateral normal maxilla bone. Polyetheretherketone meshes with thicknesses of 0.5 and 0.6 mm were designed, and four apertures were designed for each thickness, which were 0, 0.25, 0.35, and 0.45 mm, separately. A three-dimensional model of the right maxilla defect area repaired by polyetheretherketone mesh implantation was established. 100 N was loaded on the polyetheretherketone mesh corresponding to the alveolar crest for mechanical finite element analysis. RESULTS AND CONCLUSION: (1) The Von Mises stress was mainly concentrated at the crest of alveolar ridge. The concentrated area of the maximum Von Mises stress of polyetheretherketone mesh obviously reduced with the increase of thickness. The maximum Von Mises stress of polyetheretherketone meshes with different thicknesses increased with the increase of aperture. Among them, the ratio of the maximum Von Mises stress to its yield strength was 0.92 and 0.97 in the polyetheretherketone meshes with no hole and 0.25 mm aperture in the group of 0.6 mm, and > 1 in the other groups. (2) The Von Mises strain was mainly concentrated at the crest of alveolar ridge. The concentrated area of the Von Mises strain of polyetheretherketone meshes reduced with the increase of thickness. When the aperture increased from 0 mm to 0.25 mm, the strain change of the polyetheretherketone mesh was negative. When the aperture increased from 0.25 mm to 0.35 mm and 0.35 mm to 0.45 mm, the strain change of the polyetheretherketone mesh was positive. (3) It is concluded that according to the maximum Von Mises stress analysis, the non-hole and 0.25 mm aperture polyetheretherketone meshes in the group of 0.6 mm met the requirements of mechanical properties. Through the analysis of the maximum Von Mises strain, it was found that the polyetheretherketone mesh with thickness of 0.6 mm and aperture of 0.25 mm was the most stable, and plastic deformation was not easy to occur.   Figures and Tables | References | Related Articles | Metrics

Select

Repairing equivalent injury of oral mucosa with concentrated growth factor fibrin membrane combined with recombinant human epidermal growth factor active protein polypeptide complex He Ruya, Liu Yunling, Nie Minhai, Liu Xuqian 2023, 27 (12):  1848-1855.  doi: 10.12307/2023.101 Abstract ( 590 )   PDF (2245KB) ( 238 )   Save BACKGROUND: The integrity and functionality of oral mucosa are of great biological significance for isolating external stimulus and resisting the invasion of pathogenic microorganisms. In recent years, concentrated growth factor and recombinant human epidermal growth factor have become two research hotspots in the field of soft tissue injury regeneration and repair.   OBJECTIVE: To investigate the repair value of autogenous concentrated growth factor fibrin membrane combined with recombinant human epidermal growth factor active protein polypeptide complex for oral mucosa equivalent injury.   METHODS: The autogenous concentrated growth factor and the autogenous concentrated growth factor fibrin membrane combined with recombinant human epidermal growth factor composite fibrin membrane were prepared respectively. Human gingival fibroblasts and human immortalized keratinocytes were cultured on concentrated growth factor fibrin membrane and concentrated growth factor + recombinant human epidermal growth factor fibrin membrane, respectively. The proliferation of cells on the membrane was compared by histological staining. The 24 BALB/c - nude mice were randomly divided into control group (group A ) and back reconstruction group (group B: blank operation; Group C: concentrated growth factor fibrin membrane was covered after operation; Group D: concentrated growth factor + recombinant human epidermal growth factor fibrin membrane was covered after operation). The effect of wound repair in each group was evaluated by histomorphology and immunology, and the tensile resistance of repaired tissue in each group was detected by biomechanics at the weekend of the third week.   RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining, SP immunohistochemistry, and immunofluorescence showed that cell proliferation of human gingival fibroblasts and human immortalized keratinocytes on concentrated growth factor + recombinant human epidermal growth factor fibrin membrane was significantly higher than that on concentrated growth factor fibrin membrane. (2) Hematoxylin-eosin staining and Masson staining showed that in group B, the epidermal layer was basically healed; the thickness of the spinous cell layer was reduced; and the amount of collagen fibers was small and discontinuous; in group C, the keratinocyte layer, spinous cell layer, and basal cell layer had different degrees of thickening; the epithelial spikes were reduced; and the collagen fibers were thick and dense, surrounded by new blood vessels. Group D showed similar performance to group C, but the number of collagen fibers, fibroblasts and new blood vessels increased remarkably. (3) Repair tissue tensile stress peak was group A> group D > group C > group B (P < 0.05). (4) These findings indicate that compared with concentrated growth factor fibrin membrane, concentrated growth factor fibrin membrane combined with recombinant human epidermal growth factor active protein polypeptide complex can not only promote the attachment and proliferation of human gingival fibroblasts and human immortalized keratinocyte, but also promote the equivalent injury healing of oral mucosa, increase the collagen fiber content and tensile strength of the damaged area, and show better repair value.  Figures and Tables | References | Related Articles | Metrics

Select

Osseointegration of micro-grooved patterns of porous hydroxyapatite scaffolds with implants after repairing large-area canine mandibular defects Li Jing, Chen Zhenghui, Kaidiliya·Yalikun, Liu Chang, Jiang Sijing, Mu Yandong 2023, 27 (12):  1920-1926.  doi: 10.12307/2023.023 Abstract ( 532 )   PDF (1355KB) ( 378 )   Save BACKGROUND: Preliminary studies have shown that micro-grooved patterns of porous hydroxyapatite have good osteoinductivity, biocompatibility, and osteoconductivity, which provides a new idea for clinical repair of jaw defects and expansion of implantation. OBJECTIVE: To observe the osseointegration of the micro-grooved patterns of porous hydroxyapatite with the dental implant after repairing large-area defect of the canine mandible. METHODS: Micro-grooved patterns of porous hydroxyapatite were made. Eight beagle dogs were randomly divided into experimental group and control group (n=4 per group). Bilateral mandibular premolars of the dogs were extracted. Three months later, two cylindrical bone defects of 8 mm×10 mm were fabricated. The experimental group was implanted with micro-grooved patterns of porous hydroxyapatite and the control group was implanted with autologous bone. Three months later, a 4 mm × 10 mm Dentium implant was implanted in the bone defect repair area. Samples were taken at 4 and 12 weeks after implantation. Cone beam CT examination, Micro-CT scan, histological examination, and implant resonance frequency analysis were performed.  RESULTS AND CONCLUSION: (1) Cone beam CT showed that there were some low-density shadows at the implant-osseointegration interface between the experimental group and the control group 4 weeks after the operation. At 12 weeks after the operation, the area of the implant-osseointegration surface increased in the experimental group and the control group. The implant was closely combined with the implant material, and there was no obvious shadow. (2) Micro-CT data analysis showed that the amount of bone covered on the implant surface in the experimental group was less than that in the control group 4 weeks after operation (P < 0.05). There was no significant difference in the amount of bone covered on the implant surface between the two groups at 12 weeks (P > 0.05). (3) Histological morphology: Hematoxylin-eosin, Masson and methylene blue-acid fuchsin staining showed that new bone formation was seen in both groups at 4 weeks. The bone contact rate in the experimental group was less than that in the control group (P < 0.05). At 12 weeks, the amount of bone around the implants in the two groups increased significantly. There was no significant difference in bone contact rate between the two groups (P > 0.05). (4) The resonance frequency analysis of the implants showed that the implant stability quotient of the experimental group was lower than that of the control group at 4 and 12 weeks after implantation (P < 0.05), but the implants of the two groups were stable in each period. (5) It is concluded that micro-grooved patterns of porous hydroxyapatite can repair large-area defects of canine jaws and induce the new bone formation, showing perfect osseointegration with implants.  Figures and Tables | References | Related Articles | Metrics

Select

Near infrared photoresponsive nanoparticles loaded with LXR agonists for photothermal immunotherapy Gan Tian, Wang Wenyuan, Yan Shujin, Hao Lan, Ran Haitao, Wang Zhigang, Xia Jizhu 2023, 27 (12):  1863-1869.  doi: 10.12307/2023.042 Abstract ( 509 )   PDF (1908KB) ( 134 )   Save BACKGROUND: Breast cancer seriously threatens the physical and mental health of women around the world. The development of early accurate diagnosis and efficient treatment strategies for breast cancer is crucial to improve the chances of survival of patients.  OBJECTIVE: To prepare new multifunctional targeted nanoparticles (PLGA-IR780-RGX104) containing IR780 and LXR agonist (RGX104), and to explore the effect of basic physicochemical properties, photoacoustic signal in vitro, and photothermal therapy combined with immunotherapy for breast cancer.  METHODS: (1) Using poly(lactid-co-glycolide) as carrier, new multifunctional targeted nanoparticles (PLGA-IR780-RGX104) were prepared by double emulsification method, and their physicochemical properties and effect of photoacoustic imaging in vitro were demonstrated. (2) Mouse breast cancer cells 4T1 in logarithmic growth phase were taken and cultured in five groups: PBS group, PBS+laser irradiation group, PLGA-IR780-RGX104 group, PLGA-RGX104+laser irradiation group, and PLGA-IR780-RGX104+laser irradiation group. Each group contained 40, 50, 60, 70, and 80 mg/L mass concentrations. After culturing for 24 hours, the cell viability was detected by Cell Count Kit-8 assay. (3) 4T1 cells and bone marrow cells were co-cultured in a Transwell chamber under the stimulation of granulocyte-macrophage colony-stimulating factor and were divided into seven groups: 4T1 cell-free group, PBS group, free RGX104 group, PLGA-IR780 group, PLGA-IR780+laser irradiation group, PLGA-IR780-RGX104 group, and PLGA-IR780-RGX104+laser irradiation group. After 6 days of culture, flow cytometry was used to evaluate the number of myeloid-derived suppressor cells in bone marrow cells of each group.  RESULTS AND CONCLUSION: (1) The prepared new multifunctional targeting nanoparticles were uniform in dispersion and size. The individual nanoparticle was spherical. The average particle size was 275.00 nm and the average potential was -12.00 mV. The encapsulation rates of IR780 and RGX104 were 93.47% and 84.30%, respectively. The drug loading of IR780 and RGX104 was 4.20% and 6.68%, respectively. After laser irradiation, the release rate of RGX104 increased significantly. The nanoparticles exhibited an obvious photoacoustic signal, which got stronger as the concentration increased. (2) With the increase of the mass concentration of the nanoparticle solution, the cell viability in the PLGA-RGX104-IR780+laser irradiation group decreased sequentially, and was significantly lower than that in the other four groups at the same mass concentration (all P < 0.000 1). (3) The number of myeloid-derived suppressor cells in the PLGA-IR780-RGX104+laser irradiation group was less than that in the PBS group, PLGA-IR780+laser irradiation group, and PLGA-IR780-RGX104 group (all P < 0.000 1), and was comparable to the 4T1 cell-free group and the free RGX104 group (P > 0.05). (4) The results showed that the new multifunctional targeted nanoparticles containing IR780 and LXR agonist (RGX104) could be used in photoacoustic imaging guided photothermal therapy combined with immunotherapy of breast cancer.  Figures and Tables | References | Related Articles | Metrics

Select

Nanocellular vesicles loaded with curcumin promote wound healing in diabetic mice Su Meng, Wang Xin, Zhang Jin, Bei Ying, Huang Yu, Zhu Yanzhao, Li Jiali, Wu Yan 2023, 27 (12):  1877-1883.  doi: 10.12307/2023.011 Abstract ( 709 )   PDF (1499KB) ( 851 )   Save BACKGROUND: Mesenchymal stem cells-derived exosome and curcumin can enhance the diabetic wound healing. However, the yield of exosome is low, while curcumin has relatively unstable structure and poor solubility, which affects the repair effect.  OBJECTIVE: To observe the therapeutic effect of the nanocellular vesicles loaded with curcumin for the refractory wounds in diabetic mice.  METHODS: Primary bone marrow mesenchymal stem cells were harvested from limbs of C57BL/6J suckling mice. Nanocellular vesicles loaded with curcumin were prepared via micro-extrusion mechanism. Encapsulation efficiency and drug loading of vesicles were detected. (1) In vitro, the effect of nanocellular vesicles on fibroblast NIH-3T3 proliferation at different mass concentrations (0, 10, 20, 40, and 80 mg/L) was detected by cell counting method. The effect of nanocellular vesicles (40 mg/L) on fibroblast migration was detected by Transwell assay. The effect of curcumin on tumor necrosis factor α and interleukin-6 mRNA expression were detected in RAW 264.7 macrophages induced by lipopolysaccharide. (2) In vivo, twenty-four adult C57BL/6J mice were taken and injected intraperitoneally with streptozotocin to establish diabetic models. Skin wounds with two 6 mm diameter wounds were produced on the backs of diabetic mice after modeling. Group A was injected with PBS; group B was injected with nanocellular vesicles; and group C was injected with curcumin solution; group D was injected with curcumin-loaded nanocellular vesicles (n=6 per group). The wound healing and histomorphological changes were observed.   RESULTS AND CONCLUSION: (1) The encapsulation rate of vesicles was 42%, and the drug loading rate was 2.3%. Nanocellular vesicles with different mass concentrations could promote the proliferation of fibroblasts. Of them, the concentration of 40 mg/L had the best proliferation effect. Nanocellular vesicles 40 mg/L promoted the migration of fibroblasts. Curcumin decreased the LPS-stimulated inflammatory response in macrophages. (2) After 14 days of wound modeling, the wounds in groups B, C, and D were significantly reduced, and the wound area in group D was the smallest. Hematoxylin-eosin staining and Masson staining showed that there was a large amount of granulation tissue formation and collagen fiber deposition in groups B, C, and D after 7 days, among which group D had the most. At 14 days after the wound modeling, the granulation tissue formation and collagen fiber deposition in groups B, C, and D further increased, and the changes were most remarkable in group D. (3) These results suggested that the nanocellular vesicles loaded with curcumin showed their synergistic role in promoting diabetic wound healing. Figures and Tables | References | Related Articles | Metrics

Select

Comparison of platelet-rich plasma, concentrated growth factor and 3D micro-nanostructure composite scaffolds in repair of rabbit radius defects Feng Junming, Xiong Xianmei, Ma Liqiong, Zhang Yan, Chen Zijie, Li Shijie, Chen Baixing, Jiang Ziwei, Zeng Zhanpeng, Gao Yijia 2023, 27 (12):  1906-1913.  doi: 10.12307/2023.036 Abstract ( 535 )   PDF (4894KB) ( 473 )   Save BACKGROUND: In recent years, platelet-rich plasma, concentrated growth factors, and 3D-printed nanoscale hydroxyapatite scaffolds have become popular research materials for bone transplantation. At present, the research directions of these materials are scattered, and there are few existing studies targeting large segments of bone and lack of comparison of different types of materials. Because the main component of long diaphysis is cortical bone, its healing is challenging. OBJECTIVE: To evaluate and compare the effects of platelet-rich plasma, concentrated growth factor, and 3D micro-nanostructure composite scaffold on bone defect healing.  METHODS: Thirty-two New Zealand white rabbits were enrolled to prepare radial bone defect model of 15 mm. According to the graft, they were divided into four groups (n=8): blank group (no treatment), platelet-rich plasma group (platelet-rich plasma), concentrated growth factor group (concentrated growth factor) and 3D composite scaffold group (3D micro-nanostructure composite scaffold). X-ray examination was performed at 1 day, 6 and 12 weeks postoperatively. Behavioral observation was performed at 12 weeks postoperatively. The rabbit ulnar and radial bone specimens were taken for Micro CT scanning to compare bone mineral density and bone volume fraction. Finally, the bone specimens were sliced and observed under a microscope.  RESULTS AND CONCLUSION: (1) The platelet-rich plasma, concentrated growth factor, and 3D composite scaffold groups had different volumes of new bone with little behavioral difference, while the blank group had almost no new bone formation and obvious claudication occurred at 12 weeks after operation. (2) X-ray imaging was better in each intervention group than that in the blank group at 6 and 12 weeks after surgery. The difference in gray values was obvious between the intervention groups, but there was no significant difference between platelet-rich plasma and concentrated growth factor groups at 12 weeks. (3) At 12 weeks after surgery, there was no statistically significant difference in bone mineral density and bone mass between the platelet-rich plasma and concentrated growth factor groups, but all parameters were better than those in the 3D composite scaffold group. (4) It is concluded that undoubtedly platelet-rich plasma and concentrated growth factor can promote the early formation of new bone, but there is no significant difference in the long-term effects of platelet-rich plasma and concentrated growth factor. The inorganic scaffold made of hydroxyapatite is difficult to promote the healing of bone defects completely, and other organic components must be added to improve its performance to maximize the osteogenic effect. Figures and Tables | References | Related Articles | Metrics

Select

Feasibility of tea polyphenol-treated bovine pericardial decellularized tissue scaffolds as artificial esophageal repair materials Li Qin, Sun Yangyong, Wu Hao, Liu Xiaohong, Xu Zhiyun 2023, 27 (12):  1832-1836.  doi: 10.12307/2023.005 Abstract ( 500 )   PDF (1901KB) ( 98 )   Save BACKGROUND: Decellularized tissue scaffolds have been used in vascular, cardiovascular, skin, pulmonary, and urology fields, and have gradually become good candidates for esophageal tissue engineering. OBJECTIVE: To investigate the feasibility of tea polyphenol-treated bovine pericardial decellularized tissue scaffolds as artificial esophagus materials.  METHODS: The bovine pericardium was decellularized and made into tissue scaffolds, which were treated with PBS, glutaraldehyde or tea polyphenol. Totally 16 SD rats were randomly assigned to four groups (n=4). In group A, PBS-treated decellularized bovine pericardial tissue scaffolds were sutured to esophageal defects. In group B, glutaraldehyde-treated decellularized bovine pericardial tissue scaffolds were sutured to esophageal defects. In group C, tea polyphenol-treated decellularized bovine pericardial tissue scaffolds were sutured to esophageal defects. In group D, the abdomen was sutured after exposing the esophagus. At 4 weeks after the operation, the changes in body weight, anastomotic stoma, hematoxylin-eosin staining and actin α antibody immunohistochemical staining at the repaired site were observed. RESULTS AND CONCLUSION: (1) The general observation showed that in group A, the esophageal defect site had granulation hyperplasia; the stenosis was not obvious; and part of the esophageal patch material fell off. In group B, one patient had anastomotic leakage after operation. The granulation tissue in the esophageal defect site proliferated obviously and the large patch tissue protruded into the esophageal cavity. In group C, granulation tissue hyperplasia was found at the esophageal defect site; the defect site was supported by the artificial esophagus without obvious stenosis. (2) There was no significant difference in body weight between groups A, B and C and group D at 4 weeks after operation (P > 0.05). (3) Hematoxylin-eosin staining demonstrated that in group A, granulation hyperplasia was seen at the esophageal defect site; a large number of inflammatory cells infiltrated; and the newly formed esophageal mucosa was partially covered with the patch tissue. In group B, the granulation tissue at the esophageal defect site had obvious proliferation, accompanied by infiltration of a large number of inflammatory cells. Inflammatory cell infiltration could be seen around the patch, and the esophageal mucosa was not covered with the patch tissue. In group C, granulation tissue proliferated at the esophageal defect site, and the infiltration of inflammatory cells was mild. Numerous new cells were seen in the artificial esophageal patch. The tissue structure of the original patch was unclear, and the esophageal mucosa completely covered the defect tissue. (4) Immunohistochemical staining exhibited that no actin α-positive cells were found in groups A and B, while blue-stained nuclei were seen, the original patch structure was loose, and actin α-specifically stained neovascular tissue was visible in group C. (5) It is concluded that the tea polyphenol-treated bovine pericardium decellularized tissue scaffold can be served as a good substitute for artificial esophagus. Figures and Tables | References | Related Articles | Metrics

Select

Eyelid reconstruction in situ using autologous tendon Zheng Liang, Yu Wen, Yang Fan, Zhao Xiangyi 2023, 27 (12):  1837-1841.  doi: 10.12307/2023.013 Abstract ( 558 )   PDF (1075KB) ( 215 )   Save BACKGROUND: Finding a tarsal substitute is the key to eyelid reconstruction, but current materials exist insufficiency. According to the biological characteristics of autologous tendon, it has the potential as a tarsal substitute.   OBJECTIVE: To observe the effect and histopathological changes of autologous tendon as a tarsal substitute transplanted for eyelid reconstruction in rabbits. METHODS: Eyelid defect models on the lower eyelids of 13 healthy New Zealand white rabbits were prepared. The eyelid reconstruction in situ was performed autologous tendon in the right lower eyelids (tendon group) and allogeneic sclera material (sclera group) on the upper eyelids of fellow eyes. The changes of eyelids were observed every day after operation. After 4 weeks, bilateral meibomian complexes were taken for biomechanical test and hematoxylin-eosin staining to observe vascularization and complex outcome.   RESULTS AND CONCLUSION: (1) After operation, the bilateral eyelid incision of the rabbit had slight redness, swelling and conjunctival hyperemia, which subsided in approximately 5 days. The incision healed well at 4 weeks after implantation. There was no obvious rejection of the implant, graft exposure, or eyelid closure obstacle. The cornea was intact. Eye movement was good. (2) Hematoxylin-eosin staining exhibited that the graft in the tendon group had a clear border, and the periphery was surrounded by meibomian gland cells. Collagen fibers in the center of the graft were seen in a cord-like parallel arrangement. Part of the fibrous structure at the border of the tendon was unclear. New capillaries were scattered around the graft, and there was no obvious inflammatory cell infiltration around the graft. In the allogeneic sclera group, the allogeneic sclera was replaced by collagen fibers, and the cells were disorderly arranged. (3) The maximum load of the eyelid was (10.521±3.497) and (9.450±4.032) N in the tendon group and allogeneic sclera group, respectively. The tensile displacement at the maximum load was (6.110±0.347) and (4.590±0.732) mm in the tendon group and allogeneic sclera group, respectively. Young’s modulus of elasticity was (5.562±1.156) and (2.575±0.978) MPa in the tendon group and allogeneic sclera group, respectively. There were significant differences between groups (P < 0.05). (4) Autologous tendon has a good histocompatibility with tarsal plate, which can achieve the physical characteristics and reconstruction effect of eyelid in situ reconstruction.  Figures and Tables | References | Related Articles | Metrics

Select

Vascular regeneration of the prefabricated flap using expanded polytetrafluoroethylene membrane barrier material Song Peng, Liu Yizheng, Lei Zhen 2023, 27 (12):  1914-1919.  doi: 10.12307/2023.041 Abstract ( 488 )   PDF (1172KB) ( 240 )   Save BACKGROUND: Although prefabricated flap is an ideal method to repair composite defects, the risk of flap necrosis is still an urgent problem to be solved. Therefore, promoting the revascularization of prefabricated flap can improve its survival rate and reduce complications.  OBJECTIVE: To investigate the effect of expanded polytetrafluoroethylene membrane barrier material on vascular regeneration of prefabricated flap in rats.  METHODS: Thirty SD rats were randomly divided into three groups with 10 rats in each group: control group, silica gel membrane group and expanded polytetrafluoroethylene group. In the silica gel membrane group and expanded polytetrafluoroethylene group, bilateral back arbitrary flaps (7.5 cm long and 1.5 cm wide) were prefabricated by the barrier delay method. Silica gel membrane and expanded polytetrafluoroethylene membrane were implanted under the flap. In the control group, the flap was prefabricated with non-barrier delay method, and the flap was directly sutured in situ without barrier under the flap. The vascular regeneration was observed after operation. At 14 days after operation, the flap tissue was stained with hematoxylin and eosin. Immunohistochemistry for vascular endothelial growth factor and CD34 was utilized to detect the activity of superoxide dismutase and the level of malondialdehyde.  RESULTS AND CONCLUSION: (1) At 2 weeks after operation, the flap was cut again. In the silica gel membrane group, some rats had axial vascular regeneration and one rat had silicone curl. All rats in the expanded polytetrafluoroethylene group had obvious axial vessels. (2) The microvessel density of expanded polytetrafluoroethylene group was significantly higher than that of control group and silica gel membrane group (P < 0.05). The number of CD34 positive vessels in expanded polytetrafluoroethylene group was significantly higher than that in the control and silica gel membrane groups (P < 0.05). The integral absorbance of vascular endothelial growth factor protein in the expanded polytetrafluoroethylene group was significantly higher than that in the control and silica gel membrane groups (P < 0.05). (3) The activity of superoxide dismutase in the expanded polytetrafluoroethylene group was higher than that in the silica gel membrane group and control group (P < 0.05), and the level of malondialdehyde was lower than that in silica gel membrane group and control group (P < 0.05). (4) Using expanded polytetrafluoroethylene membrane as barrier delay material can promote the angiogenesis of prefabricated flap in rats, reduce oxidative stress, and improve the survival rate of the flap.   Figures and Tables | References | Related Articles | Metrics

Select

Biocompatibility of 3D printed polyetheretherketone/hydroxyapatite composites Wu Boyu, Ye Kai, Chen Jiahan, Wang Jianghua, Wurikaixi·Aiyiti, Jiang Houfeng, Teng Yong 2023, 27 (12):  1932-1937.  doi: 10.12307/2023.079 Abstract ( 574 )   PDF (1841KB) ( 371 )   Save BACKGROUND: Polyetheretherketone materials have the advantages of stable physical, chemical and mechanical properties, radiation transparency and elastic modulus similar to human bones, but there is a biological inertia problem, which limits its clinical application. OBJECTIVE: To evaluate the biocompatibility of polyetheretherketone/hydroxyapatite composites prepared by fused deposition molding 3D printing.  METHODS: Polyetheretherketone and polyetheretherketone/hydroxyapatite composite materials (hydroxyapatite mass fraction 10%) were prepared by fused deposition molding 3D printing technology, which were denoted as polyetheretherketone group (control group) and polyetheretherketone/hydroxyapatite group (experimental group). Passage 3 mouse preosteoblasts (MC3T3-E1) were co-cultured with the extracts of the two groups of materials, separately.  Cells cultured alone were used as positive controls. The survival and proliferation of MC3T3-E1 were detected by Live/Dead fluorescence staining and CCK-8 assay. The adhesion growth and proliferation of MC3T3-E1 on the surface of the materials were observed by scanning electron microscopy.  RESULTS AND CONCLUSION: (1) Live/Dead fluorescence staining exhibited that the MC3T3-E1 cells in two kinds of extracts grew well and presented good viability. The cell survival rate was higher than 90%. The two materials had no obvious cytotoxicity. The cells proliferated well with the extension of culture time. (2) The results of CCK-8 assay showed that the cytotoxicity of the two kinds of materials was qualified. The proliferation absorbance value of cells in the experimental group was higher than that of positive control group and control group at 3, 5 and 7 days of culture (P < 0.05). (3) Scanning electron microscope observation showed the good adhesion and cell spreading. Matrix secretion of MC3T3-E1 cells was numerous in the experimental group at 1 day of inoculation. The number of cells adhering to the surface of the two groups of materials increased, and more matrixes were secreted at the same time, among which the number of cells adhering to the surface of the experimental group and the secretion of matrix were more at 3 days of inoculation. The overlapping growth of cells appeared on the surface of the two groups of materials, and the cells in the experimental group were more efficient in spreading growth and secreting matrix at 7 days of inoculation. (4) These findings verify that the polyetheretherketone/hydroxyapatite composite prepared by 3D printing has good biocompatibility.  Figures and Tables | References | Related Articles | Metrics

Select

Influencing factors and mechanisms of platelet-rich plasma in tendinopathy Lu Jialin, Gao Yao, Li Han, Zhang Ziyu, Wang Yiming, Xu Rui, Wang Zhonghan, Jin Hui 2023, 27 (12):  1944-1953.  doi: 10.12307/2023.077 Abstract ( 693 )   PDF (954KB) ( 283 )   Save BACKGROUND: Platelet-rich plasma has been widely used as a promising therapeutic agent for tendinopathy, because it contains a variety of cytokines and other protein components. However, there are controversies about the optimal treatment regimen and efficacy of platelet-rich plasma for tendinopathy. OBJECTIVE: To summarize the factors that contributed to the efficacy of platelet-rich plasma and the underlying mechanism of platelet-rich plasma in the improvement of tendinopathy, as well as to prospect the potential of platelet-rich plasma combination therapy in the treatment of tendinopathy.  METHODS: Articles published from inception to July 2021 were retrieved on PubMed, Web of Science, and CNKI by the keywords of “PRP, tendinopathy, preparation, mechanism, combination therapy”. A total of 490 articles were picked, and 135 articles were finally selected for this review according to the criteria of inclusion and exclusion.    RESULTS AND CONCLUSION: Currently, the preparation process of platelet-rich plasma is multifarious. The therapeutic efficacy of platelet-rich plasma is depended on several factors such as preparation methods, composition, activation methods, way of administration, and number of applications. The best way to evaluate the efficacy of platelet-rich plasma in tendinopathy is to determine the role of specific growth factors in molecular signaling pathways associated with tendon repair. In vitro and in vivo basic researchers have found that platelet-rich plasma has the ability to promote tissue regeneration, modulate inflammation and increase mechanical strength, elastic modulus and mechanical load of tendons. In addition, factors influencing tendinopathy treatment are multiple. Platelet-rich plasma combined with other treatment strategy may overcome the limitations of single platelet-rich plasma to a certain extent and has practical significance for treating tendinopathy. Combined with tissue engineering and clinical methods, the therapeutic effect of platelet-rich plasma will be enhanced to a certain degree, can achieve better prognosis, and further expand the application of platelet-rich plasma.  Figures and Tables | References | Related Articles | Metrics

Select

Grophene-family nanomaterials in the treatment of periodontal disease: beneficial for osteogenic differentiation and reconstruction of periodontal support tissues Ren Wenyan, Liu Xue, Wang Yiyu 2023, 27 (12):  1954-1960.  doi: 10.12307/2023.106 Abstract ( 695 )   PDF (1197KB) ( 260 )   Save BACKGROUND: Grophene-family nanomaterials have received extensive attention from scholars due to their superior properties, and their properties and applications have become research hotspots. The current research mainly involves antibacterial properties, tissue engineering scaffolds, induction of odontogenic stem cell regeneration and osteogenic differentiation, which coincides with the treatment goals of periodontal disease.  OBJECTIVE: To review the research progress of grophene-family nanomaterials in the field of periodontal disease treatment, and to confirm that grophene-family nanomaterials have good application prospects in the prevention and treatment of periodontal disease.  METHODS: The relevant articles published from January 2000 to April 2022 in CNKI, Wanfang Database, ScienceDirect, PubMed, and Medline databases were searched by computer. The search terms were “grapheme, periodontal disease, biocompatibility, antibacterial mechanism, odontogenic stem cells, guided tissue regeneration”. By reading the title and abstract of the preliminary screening, the literature that was not related to the theme of the article was excluded. According to the inclusion and exclusion criteria, 67 articles were finally included for the result analysis.  RESULTS AND CONCLUSION: (1) Grophene-family nanomaterials have a good inhibitory effect on common pathogenic bacteria of periodontal disease through their own antibacterial and drug-loaded antibacterial effects. (2) Grophene-family nanomaterials can be used as tissue engineering scaffolds to carry cells and increase adhesion. It can promote cell migration and proliferation, and the growth and osteogenic differentiation of dental stem cells, which is conducive to the reconstruction of periodontal support tissues. Figures and Tables | References | Related Articles | Metrics

Select

Surface treatment of dental implant materials and their antibacterial and osteoinductive ability Wang Yuesheng, Gao Wei, Peng Cheng 2023, 27 (12):  1961-1968.  doi: 10.12307/2023.108 Abstract ( 1054 )   PDF (1997KB) ( 469 )   Save BACKGROUND: The implant material is required to show good biocompatibility, corrosion resistance, wear resistance, and excellent mechanical properties. At present, the commonly used implant materials mainly include metals and their alloys, ceramics, and high molecular polymers. Peri-implantitis caused by the growth of bacteria in the oral cavity due to the complex environment in the oral cavity, as well as the patient’s own diet and hygiene habits, is the important factor leading to the failure of the implant. More and more researchers are exploring the surface treatment and antibacterial coatings methods of the implant surface, providing osteoinductive and antibacterial properties. OBJECTIVE: To summarize the three aspects of implant materials, surface treatment technology and surface coating types for research and clinical reference. METHODS: Online search of Web of Science, CNKI, and Wanfang databases was performed to retrieve studies regarding dental implant in the biological field published between March 2011 and August 2021. The English search terms were “dental implant, dental implants materials, dental implant surface treatment, antibacterial activity”. The Chinese search terms were “surface treatment, surface coating, dental implants materials, dental implant osseointegration, peri-implantitis, antibacterial activity”. Totally 1 500 articles were retrieved. Among them, 67 articles were included.  RESULTS AND CONCLUSION: Dental implants have been widely used and developed in the clinic. As far as the implant materials are concerned, pure titanium implants still need to be improved due to their high elastic modulus and inflammation caused by them. The following developed titanium alloys also have the problem of stimulating bone growth. Tantalum and tantalum-based alloys are expensive and mostly appear in the form of coatings, which limits their clinical application. The long-term effect of ceramic implants such as zirconia still needs further observation and verification, which are brittle and easy to break. The elastic modulus of polymer materials is close to that of bone tissue, but its strength and osteogenic activity still need to be further studied. In addition, the peri-implant inflammation caused by the complex environment in the oral cavity can also lead to implant failure. Therefore, it is very necessary to carry out surface treatment and coating techniques on the surface of dental implants to promote bone formation, osseointegration and anti-infection. The application of their combination may become a major direction in future research. Figures and Tables | References | Related Articles | Metrics