Loading...

Table of Content

    18 May 2018, Volume 22 Issue 14 Previous Issue    Next Issue
    For Selected: Toggle Thumbnails
    Sustained-releasing performance of polymethyl methacrylate bone cement carrying antituberculosis drugs in vitro
    Yuan Hu-cheng, Shi Shi-yuan, Ma Wen-xin, Yang Xiao-ying, Wang Jia-ming, Wang Zi-li
    2018, 22 (14):  2133-2139.  doi: 10.3969/j.issn.2095-4344.0843
    Abstract ( 253 )   PDF (1236KB) ( 115 )   Save

      BACKGROUND: Antibiotic loaded bone cement has been well studied in clinical prevention and treatment of postoperative infection after artificial joint replacement. However, little is reported on antituberculotic-loaded bone cement.

    OBJECTIVE: To investigate the drug release properties of polymethyl methacrylate bone cement carrying antituberculosis drugs in a simulated body fluid (phosphate buffer solution, PBS).
    METHODS: The bone cement SimpLex P and antituberculosis drugs, including pyrazinamide, isoniazid, rifapentine, prothionamide, capreomycin, rifampicin, moxifloxacin, and amikacin, were mixed at 40 g:1.5 g and 40 g: 2.5 g ratios to prepare 16 groups of experimental specimens (n=5 per group). In addition, 40 g of bone cement powder was mixed with the liquid monomer to prepare a group of non-loaded bone cement specimens (control group, n=5). Either experimental or control specimens were soaked in PBS simulated body fluid, and then the extractions were taken at different time points to measure concentrations of antituberculosis drugs by high performance liquid chromatography.

    RESULTS AND CONCLUSION: The effective sustained-releasing time in the PBS simulated body fluid was 45 and 60 days for 1.5 g and  2.5 g groups of pyrazinamide, was 60 and 45 days for 1.5 g and 2.5 g groups of isoniazid, was 60 and 45 days for 1.5 g and 2.5 g groups of rifapentine, was 150 and 150 days for 1.5 g and 2.5 g groups of protionamide, was 150 and 150 days for 1.5 g and 2.5 g groups of capreomycin, was 45 and 60 days for 1.5 g and 2.5g groups of rifampicin, was 90 and 90 days for 1.5 g and 2.5 g groups of moxifloxacin, and was 60 and 90 days for 1.5 g and 2.5 g groups of amikacin, respectively. All the drug carriers had good drug release characteristics. Especially the 1.5 g and 2.5 g groups of protionamide, 1.5 g and 2.5 g groups of capreomycin, 1.5 g and 2.5 g groups of moxifloxacin and 2.5 g group of amikacin showed a longer period of drug release in accordance with the clinical need. However, our preliminary findings showed that the mechanical strength of the composite bone cement was considerably reduced by isoniazid, rifampicin, rifapentine, or protionamide, while the SimpLex P bone cement carrying pyrazinamide, amikacin, moxifloxacin, or capreomycin showed no changes in the mechanical strength. Therefore, pyrazinamide, amikacin, moxifloxacin, and capreomycin are suitable for the preparation of bone cements carrying antituberculosis drugs.

    中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程

    Figures and Tables | References | Related Articles | Metrics
    Dispersion degree of a small-dose bone cement
    Sun Hai-bo, Qi Ming, Hai Yong, Wang Xin-kuan, Zhang Wu-jun, He Ying-hua, Li Hua, Zhang Guo-fu, Zhao Ji-yang, Cao Lian-xu
    2018, 22 (14):  2140-2145.  doi: 10.3969/j.issn.2095-4344.0186
    Abstract ( 309 )   PDF (1366KB) ( 96 )   Save

    BACKGROUND: During the percutaneous vertebroplasty, the optimal dose of bone cement that can bring favorable cement dispersion and remodel the biomechanical balance of the fractured vertebrae remains controversial.

    OBJECTIVE: To investigate the dispersion degree of small dose of bone cement in vertebroplasty.
    METHODS: In this experiment, 18 sheep selected with the same condition were randomly divided into three groups (group A, group B, group C), 6 in each group. A model of thoracolumbar vertebral compression fracture (T12, L1, L2) was made in each sheep. The injected volume of bone cement in groups A, B, C was 15%, 20%, 25% of the average volume of adjacent vertebral bodies, respectively. Postoperative CT images were used to evaluate the bone cement dispersion. Dispersion degree of bone cement among the three groups was compared by the Kruskal-Wallis test.
    RESULTS AND CONCLUSION: There was no statistical difference in the dispersion degree of bone cement among the three groups, and the excellent and good rate of dispersion was over 80%. To conclude, the optimal dose of bone cement injected into the fractured vertebra is 15% of the average volume of adjacent vertebral bodies, which can achieve good dispersion degree and restore the biomechanical stability of the vertebral body. 
    Figures and Tables | References | Related Articles | Metrics
    Constructing nanosized cell-type tissue-engineered bone for repair of mandibular bone defects
    Li Dong-mei, Liu Xin-hui, Li Qing-xing
    2018, 22 (14):  2146-2151.  doi: 10.3969/j.issn.2095-4344.0844
    Abstract ( 345 )   PDF (4362KB) ( 118 )   Save

     BACKGROUND: Nanosized cell-type tissue-engineered bone is a good scaffold material possessing the merits of stem cells and nanomaterials to fabricate bone and soft tissue formation.

    OBJECTIVE: To explore the method of constructing nano-sized cell-type tissue-engineered bone and to explore its application in the repair of mandibular bone defects.
    METHODS: One New Zealand white rabbit was taken to isolate bone marrow stromal stem cells by centrifugation. Then, the cells were induced to differentiate into osteoblasts. Osteoblasts (3×108 /L, 10 μL) were inoculated into the prepared nano-phase hydroxyapatite/collagen composite to produce the nano-sized cell-type tissue-engineered bone. Another 20 New Zealand white rabbits were taken to make a unilateral puncture-type bone defect model of 15 mm×8 mm. These model rabbits were thereafter randomized into control and artificial bone groups (n=10 per group), followed by no intervention and implantation of nano-sized cell-type tissue-engineered bone, respectively. Repair effects were compared between the two groups.
    RESULTS AND CONCLUSION: (1) Under the inverted microscope, osteoblasts grew along the material in each group, and the number of cells increased with the prolongation of the culture time. (2) Under the scanning electron microscope, a large number of spindle- or polygon-shaped adherent cells grew well on the surface of the tissue-engineered bone. (3) The defect in the artificial bone group was lessened at 4 weeks after implantation and disappeared at 8 weeks after implantation, and there was no clear boundary with the surrounding tissue. In the control group, the defect size changed little at 4 weeks and reduced at 8 weeks after implantation, and a clear boundary with the surrounding tissue was observed. (4) Bone density, trabecular thickness and trabecular number were significantly higher in the artificial bone group than the control group at 4 and 8 weeks after implantation (P < 0.05). (5) At 4 weeks after implantation, many new bones at the defect site were detected in the artificial bone group, and a large number of mature bone cells were visible at 8 weeks. In the control group, a few osteoblasts were found at the defect site with low bone maturation at 4 and 8 weeks after implantation. These findings suggest that the implantation of nanosized cell-type tissue-engineered bone into the defect site can considerably promote defect healing and achieve ideal repair effects. 
    Figures and Tables | References | Related Articles | Metrics
    Tissue-engineered cartilage implantation for the treatment of full-thickness knee cartilage defects
    Feng Wen-zhe, Lu Wei, Xu Jian, Zhu Wei-min, Ouyang Kan, Peng Liang-quan, Liu Hai-feng, Li Hao, Chen Kang, Li Ying
    2018, 22 (14):  2152-2156.  doi: 10.3969/j.issn.2095-4344.0745
    Abstract ( 419 )   PDF (1232KB) ( 116 )   Save

      BACKGROUND: The use of normal hyaline cartilage to repair large areas of full-thickness knee cartilage defect  has been a hot topic recently; however, a follow-up study with a relative large number of patients is required.

    OBJECTIVE: To make a preliminary study concerning the methods and therapeutic effects of tissue-engineered cartilage (TEC) implantation for treating large-area full-thickness knee cartilage defects.
    METHODS: Twenty-one patients (23 knees) diagnosed with cartilage defect of the knee joint (Outbridge III-IV) were enrolled. The area of the cartilage defect was 3.5-11.2 cm2. All of the patients were given TEC treatment. Postoperative functional exercise of the knee joint was carried out in these patients as planned. We regularly reviewed the knee MRI and calculated visual analog scale score, International Knee Documentation Committee (IKDC) score, and Lysholm score. 

    RESULTS AND CONCLUSION: All the patients were followed up for 3 to 12 months. Postoperatively knee pain relieved obviously, and the visual analog scale score was significantly declined compared with the preoperation (P < 0.05). All the patients manifested painless 1 year after surgery. The 1-year postoperative MRI showed that the injured cartilage grew well. The thickness and MRI signal of the graft was the same as the normal cartilage, and the bone healed completely. The IKDC and Lysholm scores were significantly improved at 3, 6, 12 months after the surgery, and the difference was statistically significant before and after the surgery (P < 0.05). Overall, TEC is an improved technique of chondrocyte implantation, which is an effective and safe method for cartilage defect repair.

    中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程

    Figures and Tables | References | Related Articles | Metrics
    Acceleration of wound healing by a porous collagen/silk fibroin scaffold carrying zinc oxide nanoparticles
    Li Qing, Quan Ren-fu, Chen Li-hong, He Li-hong, Chen En-liang, Hu Hua-hui, Zheng Xuan
    2018, 22 (14):  2157-2161.  doi: 10.3969/j.issn.2095-4344.0784
    Abstract ( 416 )   PDF (4915KB) ( 200 )   Save

    BACKGROUND: Anti-infective ability determine the success or failure of skin grafting. It is one of the commonly used methods to enhance the anti-infective ability of implants by compounding antibacterial materials with scaffolds.

    OBJECTIVE: To investigate the effect of porous collagen/silk fibroin scaffolds carrying zinc oxide nanoparticles against infection and inflammation, and to evaluate its effect on wound healing.
    METHODS: Thirty-two Sprague-Dawley rats with a full-thickness wound on the back skin were randomly divided into two groups. In experimental groiup, porous collagen/silk fibroin scaffolds containing zinc oxide nanoparticles were implanted, while only collagen/silk fibroin scaffolds were implanted in control group. Wound healing was compared between the two groups by measuring residual wound area at 1, 2, 4, 8 weeks post implantation. Hematoxylin-eosin and interleukin 6 immumohistochemical staining were performed at 1, 2, 4 weeks post implantation to observe wound morphology and inflammatory reactions. Meanwhile, expression of interleukin 6 and interleukin 1β was detected by real-time PCR.

    RESULTS AND CONCLUSION: (1) At 2, 4, 8 weeks post implantation, significantly increased healing rate was observed in the experiment group compared with the control group (P < 0.05). (2) Findings from the hematoxylin-eosin staining showed that obvious inflammatory cell infiltration was observed in the control group, but less inflammation with vigorous growth of granulation tissues on the wound surface occurred in the experimental group at 1 week after implantation. Then, the wound repair was basically completed in the experimental group presenting with complete and compact epidermal tissue structure, while scar formation with no skin cover was found in the control group at 4 weeks after implantation. (3) Findings from the interleukin 6 immumohistochemical staining showed that there was interleukin 6 positive expression in both two groups to different extents; at 4 weeks after implantation, the expression of interleukin 6 was remarkably reduced in the control group, but it was still a strong positive expression, while week positive expression of interleukin 6 was observed in the experimental group. (4) Compared with the control group, the mRNA expression of interleukin 6 and interleukin 1β was both lower in the experimental group at 1, 2, 4 weeks after implantation, but there was a significant difference between the two groups at 1 and 2 weeks after implantation (P < 0.05). Overall, the porous collagen/silk fibroin scaffold carrying zinc oxide nanoparticles can effectively reduce inflammations following skin injury, and accelerate skin wound healing.

    Figures and Tables | References | Related Articles | Metrics
    Bonding effects of different adhesive materials with no ferrule effect in the dental restoration with CAD/CAM-fabricated one-piece fiber post-and-core after bypass obturation of oval root canals
    Qi Lu, Wang Xing, Wu Pei-ling
    2018, 22 (14):  2162-2167.  doi: 10.3969/j.issn.2095-4344.0841
    Abstract ( 318 )   PDF (1132KB) ( 122 )   Save

    BACKGROUND: One-piece glass fiber post-and-core achieves a good sealing between cast-post and core and provides a suitable elastic modulus of the glass fiber material. Therefore, selecting a reasonable bonding system for the CAD/CAM-fabricated fiber post-and-core with no ferrule effect has become an important issue in clinical practice.

    OBJECTIVE: To compare the bonding effects of three kinds of adhesive materials without ferrule effect in the CAD/CAM-fabricated dental restoration after bypass obturation of oval root canals.
    METHODS: Ninety extracted first mandibular premolars with the working length set to 14 mm were randomized into three groups (n=30 per group). The root canal was prepared with the ProTaper next nickel titanium system under a dental operating microscope. The bypass obturation with oval root canals was achieved using the warm gutta-percha vertical condensation technique. 1-4 # Pesso drills were used to remove the gum in the root canal, with the preparatory depth of 9 mm, but with no shoulder collar. CAD/CAM technology was used to prepare one-piece fiber post-and-cores which were bonded using the KetacTM Cem Easymix glass ion, ONE-STEP PLUS universal UV-curable adhesive and RelyXTM Unicem 2 self-adhesive resin cement in different groups. The bonding effect of three kinds of adhesive materials was analyzed by using a universal mechanical measuring instrument.
    RESULTS AND CONCLUSION: Compared with the KetacTM Cem Easymix glass ion group, the debonding force and micro-tensile strength were significantly stronger in the other two groups (P < 0.05), while compared with the ONE-STEP PLUS universal UV-curable adhesive group, the debonding force and micro-tensile strength were slightly higher in the RelyXTM Unicem 2 self-adhesive resin cement group, but there was no significant difference between the two groups. To conclude, RelyXTM Unicem 2 self-adhesive resin cement in the absence of ferrule effect can achieve better bonding effect on the CAD/CAM-fabricated one-piece fiber post-and-core after bypass obturation of oval root canals. 
    Figures and Tables | References | Related Articles | Metrics
    Effects of collagen-bioactive glass-polycaprolactone scaffold on proliferation, migration and differentiation of human dental pulp cells
    Pan Fu-qin, Liu Jian-hui, Pang Yin, Qiu Yan-li, Zhou Jing, Li Qi, Cai Chun-yi
    2018, 22 (14):  2168-2173.  doi: 10.3969/j.issn.2095-4344.0743
    Abstract ( 323 )   PDF (1179KB) ( 96 )   Save

    BACKGROUND: Collagen-bioglass-polycaprolacton (COL-BG-PCL) composites have good biocompatibility, mechanical properties and biodegradability that are beneficial to cell adhesion, proliferation and angiogenesis.

    OBJECTIVE: To study the effect of COL-BG-PCL bioactive scaffold on the proliferation, migration and differentiation of human dental pulp cells (hDPCs).
    METHODS: hDPCs were isolated and cultured on the COL-BG-PCL bioactive scaffold. MTT, cell scratch test and enzyme-linked immunosorbent assay (ELISA) assay were used to detect the proliferation, migration and differentiation abilities of hDPCs before and at 1, 3, 7, 14, 24 days after inoculation onto the COL-BG-PCL bioactive scaffold.
    RESULTS AND CONCLUSION: Compared with the cells without inoculation onto the COL-BG-PCL bioactive scaffold, (1) the proliferation ability of the cells cultured on the COL-BG-PCL scaffold was significantly enhanced (P < 0.01), and with the prolongation of the inoculation time, the cell proliferation ability was gradually increased; (2) the cell migration ability of the cells cultured on the COL-BG-PCL scaffold was significantly enhanced (P < 0.01), and with the prolongation of the inoculation time, the migration ability of the cells cultured on the COL-BG-PCL scaffold was gradually increased; (3) the level of alkaline phosphatase in the supernatant of the cells cultured on the COL-BG-PCL scaffold was significantly increased (P < 0.01), and with the prolongation of the inoculation time, the level of alkaline phosphatase in the supernatant was gradually increased. In summary, the COL-BG-PCL scaffold can promote the proliferation, migration and differentiation of hDPCs. 
    Figures and Tables | References | Related Articles | Metrics
    Influence of arch curvature and all-ceramic materials on fatigue life of fixed bridges:  a finite element analysis
    Lu Xiao-feng, Ling Li, Dong Ning
    2018, 22 (14):  2174-2178.  doi: 10.3969/j.issn.2095-4344.0778
    Abstract ( 314 )   PDF (1118KB) ( 83 )   Save

    BACKGROUND: The cyclic fatigue finite element method is more useful to study the fatigue life of the prosthesis in accordance with the actual situation of the oral cavity.

    OBJECTIVE: To study the all-ceramic fixed bridge fatigue life with different arch curvatures and materials.
    METHODS: According to the arch curvature, four sets of models (group I, 0°; group II, 30°; group III, 60°; group IV, 90°) were set up on the basis of a digital model of all-ceramic fixed bridge. Fatigue life of each model was analyzed with different materials (In-Ceram Zirconia, Zenotec, LAVA).
    RESULTS AND CONCLUSION: The stress was mostly concentrated at the join of the all-ceramic fixed bridge. It was also the most part of the stress extremum, the shortest part of fatigue life and the most easily damaged part of the material. With the increase of arch curvature, the fatigue life of Group In-Ceram Zirconia dropped from 4.6 to 1.7 years, while both Group Zenotec and Group LAVA had the fatigue life of 19.6 years. The part of minimum life was the join of the fixed bridge. These findings indicate that the expected fatigue life of In-Ceram Zirconia all-ceramic fixed bridge restoration is relatively short, which may be an inappropriate repair material in anterior and posterior positions of canine teeth. All-ceramic materials, Zenotec and Lava, can meet the clinical life expectancy under different curvatures.中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程
    Figures and Tables | References | Related Articles | Metrics
    Clinical application of three-dimensional printing implant template in the restoration of free-end missing teeth
    Zhao Dian-cai, Nie Yu-jie, Ouyang Shan, Lin Xiao-hui, Hu Xi-juan
    2018, 22 (14):  2179-2184.  doi: 10.3969/j.issn.2095-4344.0185
    Abstract ( 355 )   PDF (1133KB) ( 124 )   Save

    BACKGROUND: Three-dimensional (3D) printing technology is currently one of the most advanced industrial manufacturing technologies. The surgical template prepared based on the 3D printing technology is mainly made of resin, and a great improvement in its accuracy is required. However, the clinical application of the surgical template made of metal is rarely reported.

    OBJECTIVE: To evaluate the clinical value of 3D-printing implant template in the restoration of free-end missing teeth.
    METHODS: A prospective study was conducted in 64 enrolled patients with free end-tooth defects. All the patients were randomly assigned to receive traditional implant template (control group, n=32) or 3D-printing implant template (study group, n=32), and 3-6 months later, the patients were subjected to crown restoration. At 6 months after crown restoration, cone beam computed tomography was performed to compare the deviation of the implant tip and neck (including vertical, buccolingual, mesial-distal). Success rate and chewing rate were compared between the two groups at 6 months after crown restoration; patient satisfaction assessment was done and compared between the two groups at 1 year after crown restoration.

    RESULTS AND CONCLUSION: There were no significant differences between the two groups in the success rate and chewing rate (98.7% vs. 95.6%; 97.4% vs. 97.1%, P > 0.05). The vertical, buccolingual, mesial-distal deviations of the implant tip were significantly lower in the study group than the control group (P < 0.05), while there was no difference in the vertical and buccolingual deviations of the implant neck between the two groups (P > 0.05), and the mesial-distal deviation of the implant neck was significantly lower in the study group than the control group (P < 0.05). In addition, there was no difference in the patient satisfaction between the study and control groups (94% vs. 91%,  P > 0.05). To conclude, the 3D printing implant template can effectively reduce implant excursion based on the assurance of therapeutic efficacy and patient satisfaction, which is of great significance in the restoration of free-end tooth loss.

    Figures and Tables | References | Related Articles | Metrics
    Construction of nano-silver coating on pure titanium surface and its antibacterial effect on Staphylococcus aureus
    Wang Fu-chao, Wang Ming-wei, Li Hua-zhuang, Wang Shan-tao, Zhao Guang-zong
    2018, 22 (14):  2185-2189.  doi: 10.3969/j.issn.2095-4344.0795
    Abstract ( 314 )   PDF (1005KB) ( 129 )   Save

    BACKGROUND: Nano-silver is a new antibacterial material developed based on nano-technology. It is characterized as stable physical and chemical properties, and good electrical, optical, and catalytic performance, but its antibacterial response to Staphylococcus aureus is controversial.

    OBJECTIVE: To explore the preparation methods of nano-silver coating on pure titanium surface and to explore its antibacterial effect on Staphylococcus aureus.
    METHODS: (1) Preparation of nano-silver coating on the surface of pure titanium: Hydroxyapatite and silver powder as research objects were fully mixed at a ratio of 20:1. The mixture was ball-milled to ensure the formation of nanosized particles. The mixture of hydroxyapatite and silver powder was put into a stirrer for continuous stirring to ensure the uniform distribution. The mixture was then placed in an ethanol solution followed by insertion of a titanium plate (anode) and a stainless steel plate (cathode). The precipitated powder was obtained on the titanium surface at a voltage of 20 V, and the pure titanium surface with nano-silver coating was prepared after heat treatment in a tube resistance furnace. (2) Observation of antibacterial properties: A minimal inhibitory concentration test was used to determine the antibacterial concentration of the nano-silver coating on the pure titanium surface when shaken with Staphylococcus aureus. A scanning electron microscope was used to observe the structure of Staphylococcus aureus on the pure titanium surface with nano-silver coatings of different mass concentrations.

    RESULTS AND CONCLUSION: Nano-silver/hydroxyapatite composite coating and hydroxyapatite coating were relatively uniform. The nano-silver/hydroxyapatite composite coating was white in color but slightly yellowish. The hydroxyapatite coating was white in color. The coating surface was rough and bonded firmly. No peeling of the coating was observed under gross observation. The antibacterial ability of the nano-silver group at 37 static culture and at 37 ℃ shaking culture was significantly higher than that of the hydroxy-apatite group (P < 0.05). The absorbance value of Staphylococcus aureus at 600 nm in the nano-silver group was lower than that of hydroxyapatite group at 7, 10, 30 hours after intervention (P < 0.05). The layer cells on the nano-silver coating become lighter in color compared with those on the hydroxyapatite coating and there were cells that ruptured and died. The number of Staphylococcus aureus on the nano-silver coating was reduced, and a large number of vacuoles were found. These findings indicate that the 20:1 mixture of hydroxyapatite and silver at micron level can be used to prepare nano-silver coating through ball milling, water bath, ultrasound and heat treatment. The prepared coating can exert excellent antibacterial effects on Staphylococcus aureus.

    Figures and Tables | References | Related Articles | Metrics
    Preparation and physicochemical characterization of levofloxacin-loaded poly(lactic-co-glycolic acid) nanoparticles
    Peng Xu-feng, Luo Wen-qiang, Zhang Xin-ru, Wang Ji-hong
    2018, 22 (14):  2190-2194.  doi: 10.3969/j.issn.2095-4344.0748
    Abstract ( 402 )   PDF (2077KB) ( 119 )   Save

     BACKGROUND: Conventional formulation of levofloxacin is rapidly and completely metabolized after administration. Fortunately, nanoparticle provides a new way to solve this problem.

    OBJECTIVE: To prepare a levofloxacin-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticle that can reduce administration frequency, maintain a stable and effective plasma concentration, and also can be combined with tissue-engineered scaffold materials.
    METHODS: Levofloxacin-loaded PLGA nanoparticles were prepared by emulsion solvent evaporation method. Twenty-four rabbits were taken to investigate the effect of nanoparticle formulation on the pharmacokinetics of levofloxacin and randomized into three groups (n=8 per group): general formulation group received an injection of levofloxacin (20 mg/kg) via ear vein; non-loaded nanoparticle group received an injection of blank nanoparticles; and levofloxaxin-loaded nanoparticle group received an injection of the corresponding levofloxacin-loaded nanoparticles. At different times, blood samples were collected to analyze the drug concentration of levofloxaxin. The antimicrobial activity of the levofloxacin-loaded nanoparticle was evaluated based on the rabbit model of Escherichia coli-induced urinary tract infection. Forty-five New Zealand white rabbits were used to establish urinary tract infection models and randomly divided into three groups (n=15 per group). In negative control group, rabbits received only an injection of normal saline via ear vein. In conventional formulation group, rabbits received an injection of levofloxacin (20 mg/kg). In nanoparticle group, rabbits received an injection of the corresponding levofloxacin nanoparticles. Subsequently, blood samples were obtained, and white blood cell (WBC) count and neutrophil percentage was tested; at the same time, the middle segment morning urine was collected to detect bacteriuria and urine WBC positive rates. At 9 days, the histopathologic analysis of the bladder mucosa was done.

    RESULTS AND CONCLUSION: (1) In vivo the pharmacokinetics: Compared with the conventional formulation group, the ideal levofloxacin-loaded PLGA nanoparticles prepared under optimal conditions significantly reduced the fluctuations in plasma concentration and frequency of administration. (2) Antimicrobial activity: Escherichia coli-induced urinary tract infection was gradually in control in the conventional formulation group and levofloxacin-loaded PLGA nanoparticle group, and basically cured at 9 days after injection. In addition, the number of cured patients was basically higher in the levofloxacin-loaded PLGA nanoparticle group than the conventional formulation group at the same time point, but there was a significant difference between the two groups only at 5 days after treatment. It can be concluded that levofloxacin-PLGA nanoparticles provide a well-sustained delivery system for treatment or prevention of urinary tract infections and provide a foundation for further investigations on tissue-engineered urethral reconstruction.

    中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程

    Figures and Tables | References | Related Articles | Metrics
    Properties of a liposomes-mediated thermo-sensitive alginate/alpha-tricalcium phosphate/collagen I composite hydrogel
    Xie Yi-gang, Li Xiao-li, Chen Chang-sheng, Liao Zhen-hua, Liu Wei-qiang
    2018, 22 (14):  2197-2202.  doi: 10.3969/j.issn.2095-4344.0769
    Abstract ( 301 )   PDF (6761KB) ( 255 )   Save

    BACKGROUND: The thermo-sensitive composite hydrogels have gained increasing interest in bone regeneration domain due to their biomimetic extracellular matrix (ECM) structure, good biocompatibility, minimal invasive performance and in situ molding.

    OBJECTIVE: To prepare a thermo-sensitive injectable alginate/α-tricalcium phosphate (α-TCP)/collagen I (Alg/TCP/Col) composite hydrogel and explore its characterization.
    METHODS: Ca-carrying interdigitation-fusion vesicles (Ca-IFVs) were prepared. The liposomes carrying the optimal concentration of calcium ions were selected for the following experiments by investigating their encapsulation efficiency and drug loading rate. Alg/TCP/Col precursor solution (Alg or Alg/TCP precursor solution) was mixed with Ca-IFVs at 37 ℃ in different proportions (5, 10, 15, 20) to prepare thermosensitive hydrogels. The structure, rheology behavior, volume swelling ratio, and mechanical properties of the composite hydrogel were observed. MC3T3-E1 cells were co-cultured with Alg/TCP/Col, Alg, and Alg/TCP hydrogels, respectively. Then, morphology of the cells was observed by confocal microscopy at 1, 3, 7 days after co-culture.

    RESULTS AND CONCLUSION: (1) The pore size of the freeze-dried hydrogel was 50-100 μm, and TCP particles uniformly adhered to the surface of the Alg/TCP hydrogel surface. The Alg/TCP/Col hydrogel was a dense aggregate with collagen fibers in contrast to the Alg/TCP hydrogel. (2) The Alg/TCP/Col hydrogel exhibited a suitable phase transition temperature (Tm) between 35-39 ℃. (3) The volume swelling ratio of the hydrogel was increased with the increase of Ca-IFVs size. When the α-TCP complex was added into the Alg/TCP hydrogel, the swelling ratio decreased slightly. Alg/TCP/Col hydrogel exhibited a higher swelling ratio than the Alg/TCP hydrogel. (4) When the mixture ratio of precursor solution to liposome was 10, the compressive modulus of Alg/TCP/Col hydrogel and Alg/TCP hydrogel was significantly higher than that of the Alg hydrogel (P < 0.05). (5) When the mixture ratio of precursor solution to liposome was 10, round MC3T3-E1 cells were observed on the Alg hydrogel; the cells on the surface of the Alg/TCP hydrogel were scattered and tended to extend; the cells on the surface of the Alg/TCP/Col hydrogel had a stress-extended morphology, and grew into the hydrogel, and meanwhile, the cell number increased significantly. To conclude, the liposome-mediated Alg/TCP/Col has good mechanical properties and cytocompatibility.

    Figures and Tables | References | Related Articles | Metrics
    Artificial cornea preparation using collagen/chondroitin sulfate/fibroblast growth factor composite film
    Mao Bao-liang, Hu Bin, Jia Lei, Shan Heng-yue, Li Xiang, Wang Ying, Yuan Wan-juan, Zhang Feng-chao, Chen Jing-hua
    2018, 22 (14):  2203-2208.  doi: 10.3969/j.issn.2095-4344.0767
    Abstract ( 376 )   PDF (5189KB) ( 161 )   Save

    BACKGROUND: The traditional corneal scaffolds exhibit poor strength and biological compatibility. Little is reported on the artificial cornea prepared by collagen and chondroitin sulfate (CS), which consist of the natural corneal tissue.

    OBJECTIVE: To prepare the collagen/CS/fibroblast growth factor (FGF) composite artificial cornea with slow-release growth factor, high strength and light transmittance, as well as good biocompatibility.
    METHODS: Regenerated collagen films were prepared by 1%, 5%, 10% collagen solutions using flow casting method, and the regenerated collagen film with the best bioactivity that was prepared by 5% collagen solution was screened through a biomechanical test. Then, the CS/collagen composite film was achieved by cross-linking the CS (2, 20, 80 g/L) with collagen by using N-(3-Dimethylaminopropyl)- N’S-ethylcarbodiimide hydrochloride-N-Hydroxysuccinimide. The composite film made of 20 g/L CS was confirmed to have the best transparency, which was used to be mixed with 5, 25, 50 mg/L FGF in PBS for 24 hours to prepare the collagen/CS/FGF composite films. ELISA method was used to detect the FGF level in the supernatant. Afterwards, corneal epithelial cells were co-cultured with regenerated collagen film, collagen/CS composite film and collagen/CS/FGF composite film, respectively. After 48 hours of co-culture, cell proliferation was detected by MTT method, based on which we could screen the optimal collagen/CS/FGF composite film. After co-culture with the collagen/CS/FGF composite film for 48 and 72 hours, cell morphology was observed by confocal microscope and scanning electron microscope, respectively.

    RESULTS AND CONCLUSION: The release amount of FGF from the composite films was dependent on the initial loading amount of FGF. Meanwhile, FGF released slowly from the three kinds of composite films, and the release amount was 11%, 23%, 30% at 72 hours after culture, in accordance with the pharmacokinetic process. MTT findings indicated that the optimal loading concentration of FGF was 25 mg/L. Under the microscope, the collagen/CS/FGF composite film promoted the adhesion, growth and proliferation of corneal epithelial cells. To conclude, the collagen/CS/FGF composite film is expected to be an ideal scaffold material for artificial cornea preparation.

    Figures and Tables | References | Related Articles | Metrics
    Preparation and biocompatibility of polyethylene glycol hydrogels auto-recruiting transforming growth factor beta1
    Ju Xiao-jing, Pan Guo-qing, Liu Xing-zhi, Sun Shu-jin, Huang Li-xin, Shi Qin
    2018, 22 (14):  2209-2214.  doi: 10.3969/j.issn.2095-4344.0737
    Abstract ( 414 )   PDF (4707KB) ( 90 )   Save

    BACKGROUND: Studies have shown that bioactive molecules or polypeptides grafted onto the surface of polyethylene glycol (PEG) hydrogels can improve PEG bioactivities.

    OBJECTIVE: To manufacture PEG hydrogels capable of auto-recruiting growth factor beta1 (TGF-β1) and to study its biocompatibility.
    METHODS: Pure PEG hydrogels (group A), PEG hydrogels grafted on a cell adhesion peptide RGD peptides (group B), PEG hydrogels grafted with auto-recruited TGF-β1 peptide sensitive polypeptide HSNGLPL (group C), PEG hydrogels grafted with both RGD and HSNGLPL polypeptides (group D) were prepared. Contract angle of the hydrogel was detected in each group. Human bone mesenchymal stem cells were seeded onto four kinds of hydrogels. After cells attached, scanning electron microscope and LIVE/DEAD staining were done to observe cell-hydrogel compounds. Human bone marrow mesenchymal stem cells were co-cultured with ordinary culture medium (control) or four kinds of hydrogels for 1, 3, 5, 7 days, and the cell proliferation was detected by cell counting kit-8 assay. The four kinds of hydrogels were put into 24-well culture plates with addition of PBS containing TGF-β1, and 1 hour later, immunofluorescence staining was done.

    RESULTS AND CONCLUSION: (1) The contact angles of groups A and C were larger than those of groups B and D. (2) Under the scanning electron microscope, groups A and C had little cells attached on the hydrogel surface, but there were many cells on the hydrogel surface in groups B and D. (3) LIVE/DEAD staining showed groups A and C had little living cells, and conversely groups B and D had many living cells. (4) The results of cell counting kit-8 demonstrated that as the incubation time went on, cell proliferation activity of five different groups increased with no difference at the same time point. (5) Findings from the immunofluorescence staining showed that groups A and B had very weak fluorescence, while groups C and D had stronger green fluorescence. In conclusion, PEG hydrogels grafted with RGD and HSNGLPL polypeptides can auto-recruit TGF-β1, and have good biocompatibility.

    中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程

    Figures and Tables | References | Related Articles | Metrics
    A new self-convertible inferior vena cava filter: in vivo experimental evaluation
    Gao Xi-xiang, Zhang Jian, Gu Yong-quan, Guo Lian-rui, Tong Zhu, Li Li-qiang, Li Jian-xin, Feng Zeng-guo
    2018, 22 (14):  2215-2220.  doi: 10.3969/j.issn.2095-4344.0842
    Abstract ( 330 )   PDF (1050KB) ( 99 )   Save

    BACKGROUND: An inferior vena cava filter is an effective tool to prevent fatal pulmonary embolism. The existing filters have some shortcomings that limit their clinical application.

    OBJECTIVE: To evaluate the feasibility and capture efficiency of a new self-convertible inferior vena cava filter (SCF) in vivo.
    METHODS: L-lactide and ε-caprolactone were fused and polymerized to act as a degradable deformable switch of the filter. Medical stainless steel wire as the metal structure of the filter was combined with the degradable deformable switch to make the SCF. Eight SCFs were implanted into the inferior vena cava of eight adult Beagle dogs. The inferior vena cava angiography was performed to evaluate the release process, morphology and location of the filter. Venous angiography was performed 2 weeks later to evaluate the morphology and location of the filter and inferior vena cava patency. Detection of pulmonary embolism or other complications was performed at autopsy.

    RESULTS AND CONCLUSION: Eight SCFs were successfully implanted and positioned accurately with no tilt, and they were converted successfully at 2 weeks after the implantation, as assessed by the venous angiography. One of the eight SCFs migrated to the orifice of the right atrium, and caused asymptomatic inferior vena cava obstruction. The remaining SCFs were normally positioned with no tilt and local lesion or obstruction after deformation. No marked filling defect in the trunk of the pulmonary artery was shown by the pulmonary artery angiography. The autopsy report revealed that the filter arm had been endothelialized, and the inferior vena cava that was in contact with the filter arm had no obvious stenosis. Mild intimal hyperplasia, less than 1 mm in thickness, was found in the bottom of the filter arm, but it did not cause a stenosis in the lumen. No vena cava perforation, retroperitoneal hemorrhage, and injury of the surrounding viscera were found. Overall, the design of the SCF is feasible.

    Figures and Tables | References | Related Articles | Metrics
    Poly(lactic acid) electrospun fiber membranes carrying gemcitabine hydrochloride inhibit the growth of bone tumor
    Liu Xing-zhi, Xiang Yi, Ju Xiao-jing, Cui Wen-guo, Shi Qin
    2018, 22 (14):  2221-2226.  doi: 10.3969/j.issn.2095-4344.0756
    Abstract ( 338 )   PDF (1614KB) ( 79 )   Save

     BACKGROUND: Gemcitabine hydrochloride is a water-soluble anticancer drug that induces apoptosis in tumor cells, but it has an excessive release in vivo.

    OBJECTIVE: To evaluate the effect of poly(lactic acid) (PLA) electrospun fiber membranes carrying gemcitabine hydrochloride on the growth of human osteosarcoma cell lines MG-63.
    METHODS: PLA electrospun fiber members with (experimental) or without (control) gemcitabine hydrochloride were fabricated and characterized. Two kinds of fiber membranes were immersed in low-glucose DMEM medium, and the supernatants were collected in the two groups at 3, 5, 7 days, respectively. Passage 5 human osteosarcoma cell lines MG-63 were inoculated into 96-well plates containing low-glucose DEME with 15% fetal bovine serum, and divided into seven groups. Groups 1-3 were cultured in the experimental supernatants of 3, 5, 7 culture days, and groups 4-6 were cultured in the control supernatants of 3, 5, 7 culture days, respectively. The remaining group acted as the negative control with no supernatant. Thereafter, cell counting kit-8 was used to detect cell proliferation, and RT-PCR was used to measure expression of Bcl-2 and Bax at 3 days of culture.

    RESULTS AND CONCLUSION: (1) No obvious particle was found on the smooth and even surface of the fiber members in the experimental and control groups. There was no significant difference in fiber diameter, contact angle and tensile strength between the two kinds of fiber membranes. (2) The results of cell counting kit-8 showed that compared with the negative control group, the supernatant released from the control group had no effect on the MG-63 proliferation at different time points, while the supernatant released from the experimental group could inhibit the MG-63 proliferation at different time points (P < 0.05), and the inhibitory effect became more and more obvious with the prolongation of release time. (3) RT-PCR findings showed that compared with the control group, the supernatant released from the experimental group could increase Bax mRNA expression and decrease Bcl-2 mRNA expression at the same time point. To conclude, the PLA electrospun fiber membranes carrying gemcitabine hydrochloride can sustainably inhibit MG-63 proliferation and promote cell apoptosis.

    中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程

    Figures and Tables | References | Related Articles | Metrics
    Osteoclast activity of MG63 cells on silicon doped zirconia films prepared by cathodic arc deposition
    Zhang Shai-lin, Cheng Xiang-yu, Shi Ji-xiang, Zhou Qiang, Shi Wen-jun, Liu Fu-ying, Ji Bin
    2018, 22 (14):  2227-2232.  doi: 10.3969/j.issn.2095-4344.0738
    Abstract ( 224 )   PDF (1229KB) ( 116 )   Save

    BACKGROUND: Various surface modification techniques have been utilized as an attempt to improve the osteointegration of Ti-based implants, which is a hotspot research concerning the artificial joint prosthesis.

    OBJECTIVE: To evaluate the effect of silicon doped zirconia film on the titanium surface on relevant factors of osteoblast-like MG63 cells.

    METHODS: Silicon doped zirconia and zirconia films were respectively prepared on the titanium surface by cathodic arc deposition. Osteoblast-like MG63 cells were cultured on silicon doped zirconia film, zirconia film and pure titanium, respectively. After 1, 4, 7, 10 days of incubation, samples were collected for assay. Osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) at mRNA and protein levels were detected using real-time PCR and ELISA, respectively.

    RESULTS AND CONCLUSION: (1) At 1 day of inoculation, there was no significant difference in the OPG mRNA and protein expression among the three groups. At 4 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film and zirconia film groups was significantly higher than that in the pure titanium group (P < 0.05), but there was no significant difference between the former two groups. At 7 and 10 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film growp was highest among the three groups (P < 0.05). (2) At 1 day of inoculation, there was no significant difference in the RANKL mRNA and protein expression among the three groups. At 4 and 7 days of inoculation, the expression of RANKL mRNA and protein in the silicon doped zirconia film group was significantly lower than that in the other two groups (P < 0.05). At 10 days of inoculation, the expression of OPG mRNA and protein in the silicon doped zirconia film and zirconia film groups was significantly higher than that in the pure titanium group (P < 0.05), but there was no significant difference between the former two groups. To conclude, silicon doped zirconia film fabricated by cathodic arc deposition can enhance the expression of OPG and reduce the expression of RANKL at the same time.

    Figures and Tables | References | Related Articles | Metrics
    Spectral characteristics of burning moxa sticks
    Guo Yuan, Xu Xue-mei, Yin Lin-Zi, Ding Yi-peng
    2018, 22 (14):  2233-2238.  doi: 10.3969/j.issn.2095-4344.0740
    Abstract ( 619 )   PDF (1257KB) ( 149 )   Save

     BACKGROUND: The drug and thermal effects of moxa-wool moxibustion have been extensively studied in the clinical trials; however, the infrared radiation effects during the moxibustion are rarely reported.

    OBJECTIVE: To learn the spectrum characteristics of moxa sticks in the traditional moxibustion.
    METHODS: The herba violae, bog rush, tobacco and moxa were chosen as experimental materials. Furthermore, the moxa sticks of different storage years (1, 3, 10 years), proportions (1: 3, 1:5, 1:10), and places of production (Nanyang, Qiai) were compared. A spectral measurement platform was built by using an optical power meter to analyze the spectral characteristics of the ten kinds of materials above.

    RESULTS AND CONCLUSION: For the different materials, the herba violae and bog rush could not burn after crushed and the infrared radiation intensity of tobacco was too low, but a strong infrared emission was from the moxa with a wide range of spectrum from ultraviolet to far infrared ray. It was also found that the year of storage, proportion, place of production as well as production process had significant effects on the radiation intensity of the moxa stick. The spectrum ascended at visible-light spectrum region, reached its peak at near-infrared region, and then descended at mid-infrared and far-infrared regions. We analyzed the stability characteristics and relative total intensity of moxa stick based on statistics and mathematics. The results showed that the stability characteristics were proportional to the proportion of moxa wool, and the year of storage had stronger effect on the relative total intensity compared with the proportion of moxa wool. Herein, we systematically analyzed the spectral characteristics of different moxa sticks, thereby providing the scientific basic data for the study on the optical radiation of moxa-wool moxibustion.

    Figures and Tables | References | Related Articles | Metrics
    Stem cells combined with three-dimensional scaffolds for the treatment of osteoporotic bone defects
    Yuan Wei-jian, Wang Chen-yu, Li Chen, Yang Fan, Wang Zhong-han, Li Zu-hao, Qin Yan-guo, Liu He, Wang Jin-cheng
    2018, 22 (14):  2239-2244.  doi: 10.3969/j.issn.2095-4344.0788
    Abstract ( 284 )   PDF (1566KB) ( 152 )   Save

    BACKGROUND: Stem cells combined with a three-dimensional scaffold have great potential for the treatment of osteoporotic bone defects.

    OBJECTIVE: To introduce the application of stem cells combined with the three-dimensional scaffold in repairing osteoporotic bone defects.
    METHODS: A computer-based search of PubMed, Web of Science, Springerlink, Medline, WanFang and CNKI databases was performed for relevant articles published from 2007 to 2017 with “stem cells, scaffold, osteoporosis, bone defects” as key words in English and Chinese, repsectively. Initially, 142 articles were retrieved, and finally 45 articles were included in result analysis.

    RESULTS AND CONCLUSION: Due to the potential of self-renewal and multilineage differentiation, stem cells can be used to repair or regenerate damaged tissues, which are considered as an ideal cell source for the treatment of diseases in orthopedics. The suitable scaffold can provide a favorable microenvironment for repairing the attachment and growth of the cells related to the bone defect, which can promote the healing without additional side effects. Furthermore, stem cells combined with three-dimensional scaffolds provide a promising clinical application for the treatment of osteoporotic bone defects by regulation of bone metabolism. In addition, gene-modified stem cells with three-dimensional scaffolds bring a huge potential in the treatment of osteoporotic bone defects. In conclusion, the combination of stem cells and three-dimensional scaffolds provides a new approach for the treatment of osteoporotic bone defects, which may be one of the future therapeutic strategies.

    中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程

    Figures and Tables | References | Related Articles | Metrics
    Composite scaffolds for bone tissue engineering: application review and future direction
    Xu Gui-wen, Wurikaixi Aiyiti, Teng Yong
    2018, 22 (14):  2245-2250.  doi: 10.3969/j.issn.2095-4344.0702
    Abstract ( 298 )   PDF (997KB) ( 131 )   Save

    BACKGROUND: In general, a single-type artificial bone is difficult to meet the requirements for bone defect repair and extracellular matrix of bone tissue engineering. Compositing and processing the materials with different properties can form the composite-type artificial bone, which can either ensure the biological activity or effectively improve its mechanical properties.

    OBJECTIVE: To summarize the present situation of the application of composite-type artificial bone and prospects the development trend.
    METHODS: The literatures were retrieved from CNKI, ScienceDirect, PubMed, SpingerLink, EI Village, Wiley databases from January 2000 to April 2017. The key words were “composite scaffold, tissue engineering, artificial bone” in Chinese and English, respectively. The selected literatures were analyzed according to the inclusion and exclusion criteria.

    RESULTS AND CONCLUSION: The requirements for the scaffolds used for bone tissue engineering are complex and it should carefully consider and control various factors used in the design and preparation of scaffolds, including microporous structure, mechanical strength, degradation rate, porosity, growth factor, morphology and surface chemistry, so as to meet the bone tissue engineering applications. The preparation of tissue-engineered bone scaffold is based on biological active substances and matrix materials through a reasonable manner. It simulates the components of natural bone matrix, promotes the adhesion, proliferation and differentiation of bioactive substances, and gives play to its functions of osteogenesis. Although existing techniques and methods have made significant progress in the preparation of composite scaffolds, there is no technique or method to fully meet all the requirements for preparation of tissue-engineered bone scaffold.

    Figures and Tables | References | Related Articles | Metrics
    Repair materials for bone defects: present status, needs and future developments
    Zhou Si-jia, Jiang Wen-xue, You Jia
    2018, 22 (14):  2251-2258.  doi: 10.3969/j.issn.2095-4344.0754
    Abstract ( 1247 )   PDF (1376KB) ( 257 )   Save

    BACKGROUND: Great development has been made in the research of various repair materials and tissue-engineered bone, and different materials exhibit a strong ability to repair bone defects.

    OBJECTIVE: To review the research status and progress of repair materials for bone defects.
    METHODS: PubMed, PMC, CBM, CNKI and WanFang databases were used online to retrieve the relative articles regarding repair materials for bone defects published from June 2007 to June 2017. The key words were “biomaterials, bone repair materials, bone substitute, bone tissue engineering, bone defect, bone repair” in English and Chinese, respectively. Finally, 66 eligible articles were included, while the unrelated and repeated ones were excluded.
    RESULTS AND CONCLUSION: The main repair materials for bone defects include autologous bone, allogeneic bone, xenogeneic bone, demineralized bone matrix, bioceramics, metal materials, polymer materials, tissue-engineered bone and relative derived composites. Different materials have shown certain advantages and

    disadvantages. Clinicians should make an optimal choice in view of the characteristics of materials. Although there is a great progress in the studies of repair materials for bone defects, further investigations are warranted on how to produce highly biomimetic materials, optimize cell adhesion and migration, precisely control the expression and release of related genes and growth factors, validate clinical safety, and provide medical evidence in clinical practice.

    中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程

    Figures and Tables | References | Related Articles | Metrics
    Biocompatibility of fully biodegradable polylactic acid and its copolymers: present and future applications
    Shen Xin, Liu Xue, Su Feng, Chen Zuo-sheng, Li Su-ming
    2018, 22 (14):  2259-2264.  doi: 10.3969/j.issn.2095-4344.0734
    Abstract ( 465 )   PDF (966KB) ( 177 )   Save

    BACKGROUND: Polylactic acid and its copolymers have been widely used in biomedical fields because of their good biocompatibility and biodegradability, which have become a hotspot in the research of biomaterials.

    OBJECTIVE: To review the biocompatibility of fully degradable polylactic acid and its copolymers.
    METHODS: A computer-based online retrieval of PubMed and CNKI was performed to search relevant papers published from 2006 to 2016, with the key words of ”polylactide, polylactic acid, copolymer, biodegradability, biocompatibility, animal” in English and Chinese, respectively.

    RESULTS AND CONCLUSION: Polylactic acid and its copolymers as polyester compounds are approved by the US Food and Drug Administration for use in the biomedical field because of their good biocompatibility mainly as drug delivery carriers and temporary implants. Moreover, their side effects in clinical application have attracted attentions. Polylactide copolymers can cause some adverse reactions when used in drug delivery systems, orthopedic and skin care, and other clinical medical fields. These copolymers are deemed to have no impact on the central nervous system, eyes, cardiovessels and other tissues and organs. They also have no virtually genotoxic and carcinogenic effects. Currently, the polylactide copolymer implant mainly results in local reactions in the surrounding tissues, and no systemic reactions have been found.

    Figures and Tables | References | Related Articles | Metrics
    Application of nanostructured bioactive glasses in oral tissue regeneration
    Xie Meng-sheng, Li Xiao-jie
    2018, 22 (14):  2265-2271.  doi: 10.3969/j.issn.2095-4344.0184
    Abstract ( 443 )   PDF (1391KB) ( 107 )   Save

    BACKGROUND: The development of nanostructured bioactive glasses that are a popular material for oral tissue regeneration provides a better choice for dental tissue regeneration.

    OBJECTIVE: To summarize the research progress of nanostructured bioactive glasses in the field of oral tissue regeneration by reviewing relevant domestic and foreign literatures.
    METHODS: With the key words of “bioactive glass, nanostructure, mesoporous” in Chinese and English, we performed a computer-based search in CNKI and PubMed database for relevant articles published from January 2000 to March 2017.

    RESULTS AND CONCLUSION: Nanostructured bioactive glasses have better bioactivity, degradation, drug-loading capability and antibacterial property compared with traditional bioactive glasses. Addition of various ions, such as magnesium, zinc, strontium, copper, silver, can further improve the physiochemical and biological properties of nanostructured bioactive glasses. A variety of methods, including sol-gel, template-directed synthesis, microemulsion, flame spray and 3D printing, have been performed to fabricate nanostructured bioactive glasses, among which, 3D printing may be an ideal method in the future. Studies on nanostructured bioactive glasses are still at in vitro and animal experimental levels, though they have been confirmed to be used in regeneration of maxillofacial bone and tooth. Considering that there are still no relevant clinical reports, further investigations are needed to verify its clinical effects and safety.

    Figures and Tables | References | Related Articles | Metrics
    Adipose tissue engineering construction using adipose-derived stem cells and scaffolds in breast reconstruction
    Guo Xiao, Feng Rui
    2018, 22 (14):  2272-2277.  doi: 10.3969/j.issn.2095-4344.0772
    Abstract ( 394 )   PDF (996KB) ( 96 )   Save

    BACKGROUND: The development of adipose tissue engineering has solved a series of problems and brought new ideas for breast reconstruction.

    OBJECTIVE: To summarize the main biological characteristics of scaffolds, seed cells and adipose grafts for adipose tissue engineering construction, as well as their application prospects in breast reconstruction.
    METHODS: With the key words of “scaffold, mesenchymal stem cells, adipose tissue engineering, breast reconstruction, vascularization” in Chinese and English, respectively, a retrieval of CNKI and PubMed was performed for relevant articles published from 1999 to 2017. After initial screening, the eligible articles were further detailed, analyzed and summarized.

    RESULTS AND CONCLUSION: Scaffold materials with low immunogenicity, especially the decellularized adipose tissue, have a unique advantage in adipogenic induction that can be used to support the regeneration of human organs and tissues. Adipose-derived stem cells can also be used as the priority for adipose tissue engineering construction, which can promote tissue development and regeneration in vivo. However, much less is known about the use of adipose tissue engineering in breast reconstruction and the implementation of long-term stable growth of the adipose tissues. Further investigations are indispensable on how to realize breast reconstruction using tissue-engineered adipose so as to construct and maintain a stable structure entity throughout the entire patient’s life. Therefore, strict selection of seed cells, scaffolds and cytokines is considered pivotal in the construction of cell microenvironment.

    Figures and Tables | References | Related Articles | Metrics
    Types and properties of injection-molded thermoplastic denture base resins
    Long Yan-ming, Li Xiao-jie
    2018, 22 (14):  2278-2283.  doi: 10.3969/j.issn.2095-4344.0763
    Abstract ( 471 )   PDF (1130KB) ( 107 )   Save

     BACKGROUND: With the increasing demands on the aesthetics of dentures, non-metal clasp dentures (also known as concealed dentures or flexible dentures) that are made of injection-molded thermoplastic denture base resins, have been popularized in the dental field due to their excellent aesthetic performance, good flexibility and biocompatibility.

    OBJECTIVE: To review the types, properties and clinical applications of injection-molded thermoplastic denture base resins.
    METHODS: The first author searched PubMed, Wiley, Springer, OVID, ScienceDirect, Google and CNKI databases for relevant articles published from January 1955 to April 2017 using the key words of “polyamide AND denture, thermoplastic denture base resin, non-metal clasp denture, nylon, flexible denture” in English and Chinese, respectively.

    RESULTS AND CONCLUSION: There are five main types of injection-molded thermoplastic denture base resins used as denture materials, including polyamides, polycarbonates, polyesters, acrylics and polypropylenes, which have good elasticity, suitability, beauty and biocompatibility and can be widely used in the dental field. However, further improvement in the performance of injection-molded thermoplastic denture base resins is warranted, including unstable coloring, bacteria adhesion and difficulty in material polishing and relining.

    Figures and Tables | References | Related Articles | Metrics
    Research and application of the reamer-irrigator-aspirator
    Li Hai-feng, Gu San-jun, Yin Qu-dong
    2018, 22 (14):  2284-2289.  doi: 10.3969/j.issn.2095-4344.0744
    Abstract ( 386 )   PDF (1054KB) ( 134 )   Save

     BACKGROUND: Large volume of bone can be harvested by the reamer-irrigation-aspirator (RIA), which can be used for autologous bone graft, because there are many stromal stem cells and a variety of osteogenesis factors in the harvested bone.

    OBJECTIVE: To introduce the application progress of the RIA.
    METHODS: PubMed database was retrieved by the first author for RIA-related articles published from January 2000 to May 2017 using the keyword of “reamer-irrigator-aspirator”. A total of 87 articles were searched initially and finally 38 articles met the inclusion criteria.
    RESULTS AND CONCLUSION: Compared with harvesting bone tissues from the iliac bone, the RIA can harvest more autologous bone tissues with more bone marrow stromal stem cells. Moreover, the osteogenic effect of the harvested autologous bone is better and there are fewer complications. Therefore, the RIA has been widely used as a method of harvesting non-structural autologous bone tissues. Removal of intramedullary lesions by the RIA is used in the treatment of long bone infection, osteomyelitis and bone tumors, as well as in the removal of intramedullary cement. RIA was originally used as a special reaming during intramedullary nailing for femoral shaft fractures, which could reduce high pressure and high temperature so as to decrease the risks of fat embolism and osteonecrosis. To conclude, the RIA can achieve satisfactory outcomes and result in few complications, but the clinical use is still limited by high cost, frequent fluoroscopy, bleeding and limited indications, as well as risks for iatrogenic fractures and perforation.
    Figures and Tables | References | Related Articles | Metrics
    Absorbable material versus Kirschner wire fixation for fractures of the lateral humeral condyle in children: a Meta-analysis
    Chen Xing-guang, Lu Min-hua, Lu Lin, Wang Xiao-dong, Zou Cheng-da, Pu Chong
    2018, 22 (14):  2290-2296.  doi: 10.3969/j.issn.2095-4344.0741
    Abstract ( 368 )   PDF (1210KB) ( 116 )   Save

    BACKGROUND: Currently, there is no explicit evidence-based medicine evidence to prove the merits or demerits of absorbable materials in the treatment of fractures of the lateral humeral condyle in children.

    OBJECTIVE: To evaluate the clinical efficacies of open reduction with absorbable material versus open reduction with Kirschner wire fixation for lateral condylar fracture of the humerus in children.
    METHODS: WanFang, VIP, CNKI, CBMdisc, EMbase, PubMed were retrieved for controlled trials concerning open reduction with absorbable material versus open reduction with Kirschner wire fixation for treating lateral condylar fracture of the humerus in children. After data extraction and quality evaluations, RevMan 5.3 software was used for systematic review. Postoperative functional recovery of the elbow joint, average hospitalization expenses, adverse events, delayed union, postoperative infection, nerve injury and deformity of the elbow were compared in patients undergoing different treatments.

    RESULTS AND CONCLUSION: A total of seven articles, involving 449 children with lateral condylar fracture of the humerus, were included for this Meta-analysis. Children in test group received open reduction with absorbable material, while those in control group were subjected to open reduction with Kirschner wire fixation. For treating lateral condylar fracture of the humerus in children, no significant inter-group difference existed in the aspects of postoperative functional recovery of the elbow joint [odds ratio (OR)=0.72, 95% confidence interval (CI) (0.37, 1.41), P=0.34]; postoperative delayed union [OR=0.46, 95% CI (0.16, 1.30), P=0.14]; deformity of the elbow [OR=0.70, 95% CI (0.24, 2.10), P=0.53]. Less adverse events and postoperative infections were observed in the test group compared with the control group [OR=0.17, 95% CI (0.08, 0.38), P < 0.000 1; OR=0.09, 95% CI (0.02, 0.38), P=0.001]. However, up to now, we knew of no comparable data concerning average hospitalization expenses and indicators for nerve injury between the two groups. To conclude, compared with Kirschner wire fixation, open reduction with absorbable material can achieve similar effects on lateral condylar fractures of the humerus, but has better effects to prevent adverse events and postoperative infection. Further investigation on large-scale, double-blind, high-quality randomized controlled trials is warranted for confirming our results.

    Figures and Tables | References | Related Articles | Metrics