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    18 September 2018, Volume 22 Issue 26 Previous Issue    Next Issue
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    Magnesium phosphate/collagen peptide composite cements: the setting retardation effect of collagen peptides
    Cao Xiao-feng, Wang Yi-hu, Lu Hao-jun, Ma Ming, Guo Yan-chuan, Mao Ke-ya, Li Jiang-tao
    2018, 22 (26):  4101-4109.  doi: 10.3969/j.issn.2095-4344.0932
    Abstract ( 468 )   PDF (969KB) ( 197 )   Save

    BACKGROUND: Magnesium phosphate cement (MPC) is a kind of bone repair material with excellent biocompatibility and bioactivity, which has overcome some disadvantages of calcium phosphate cements. However, the MPC still has some drawbacks such as the fast reaction rate in the setting process, the short initial and final setting times, and the high temperature in the setting process. Collagen peptides (CP) as polypeptide mixtures have the properties of enhancing bone mineral density, and preventing and treating osteoarthritis and osteoporosis. So far, there are few reports on the composite cements composed of MPC and CP. The physicochemical properties and cytotoxicity of the composites cements have not been well documented.

    OBJECTIVE: To prepare the MPC/CP composite cement with controllable setting rate and setting reaction heat and to study the physicochemical properties and cytotoxicity of the composite cement.
    METHODS: The MPC were prepared by combining low-activity MgO, KH2PO4, and Na2B4O7•10H2O. Different amounts of CP were introduced into the MPC to form MPC/CP composite cements. We measured the initial and final setting times, the temperature evolution during the setting process and the compressive strength of the composite cements soaked in the simulated body fluid for 1 and 7 days. The MTT assay was used to evaluate the cytotoxicity of the composite cements.

    RESULTS AND CONCLUSION: The addition of CP altered the physicochemical and biological properties of the composite bone cements. With the increasing of the CP content, prolonged initial and final setting times, reduced maximum temperatures during the setting process, and delayed time for the maximum temperature were observed. The hydrated and cured products of MPC and the composite bone cement were MgKPO4•6H2O. The above experimental results suggested that the CP had a good retarding effect on the composite bone cement without changing the phase of the cured product. Experimental findings regarding the mechanical properties showed that with the increasing of the CP content, the compressive strengths of the composite cements increased firstly and then decreased. The storing time in the simulated body fluid was also the influencing factor for the compressive strength of the composite cement. Results from the MTT assay showed that the addition of CP promoted the proliferation of MC3T3-E1 cells and L929 cells. Overall findings provide a technical basis for the clinical application of MPC/CP composite cements.

     

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    Characteristics of bone filling mesh container for treating osteoporotic vertebral compression fractures in older adults
    Huang Hao-ran, Feng Li, Liang Hua, Feng De-wei, Teng Xue-ren, Yu Hua
    2018, 22 (26):  4110-4115.  doi: 10.3969/j.issn.2095-4344.0768
    Abstract ( 402 )   PDF (675KB) ( 130 )   Save

    BACKGROUND: A bone filling mesh container in the treatment of vertebral compression fractures can not only effectively restore vertebral body height and biomechanical function, but also obviously reduce the leakage of bone cement and improve the success rate of surgery. Therefore, this method has aroused great attention in the current tissue engineering research and in the treatment of vertebral compression fractures.

    OBJECTIVE: To evaluate the clinical effect of bone filling mesh container in the treatment of osteoporotic vertebral compression fractures in the older adults.
    METHODS: Thirty cases of senile osteoporotic vertebral compression fractures were prospectively analyzed. Patients aged 56-78 years presented with single segmental vertebral compression fractures and underwent bilateral percutaneous kyphoplasty with the implantation of bone filling mesh container followed by bone cement injection. We detected visual analogue scale score, percentage of the elevation of the middle and anterior vertebral bodies, posterior Cobb’s angle and Oswestry dysfunction index score at postoperative 1 day, 1 week, 1 month and 6 months, respectively.

    RESULTS AND CONCLUSION: All 30 patients completed the operation without bone cement leakage. After treatment, the visual analogue scale score, posterior Cobb’s angle and Oswestry dysfunction index score were significantly lowered in all patients (P < 0.05). However, there was no difference in the percentage of the elevation of the middle and anterior vertebral bodies at different time points after treatment. To conclude, the use of bone filling mesh container can obviously relieve patient’s pain, improve vertebral body height and protrusion deformity, and meanwhile significantly reduce bone cement leakage in patients with senile osteoporotic vertebral compression fractures.

     

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    Properties of glass ionomer cements after addition of organic dye solutions
    Wang Ping-ting, Bao Yi-jun, Liu Ying
    2018, 22 (26):  4116-4122.  doi: 10.3969/j.issn.2095-4344.0913
    Abstract ( 275 )   PDF (868KB) ( 125 )   Save

    BACKGROUND: A wall build-up prior to endodontic therapy is applied to prevent contamination of the root canals from oral cavity and to provide retention for rubber dam when root canal treatment is required to badly broken-down tooth which have lost the integrity of the external coronal tooth structure in clinical practice. However, the color of the available wall build-up materials is consistent with the tooth tissue, which often causes the loss of tooth tissues during the removal in later prosthetic phase. Therefore, it is advisable to endue materials with a distinct color that makes it chromatically different from the tooth tissue, which is of great clinical significance.

    OBJECTIVE: To compare the effect of three organic dye solutions on physicochemical and mechanical properties of reinforced glass ionomer cements (GIC) which used as wall build-up material.
    METHODS: Different concentrations of methylene blue, crystal violet, erythrosine dye solutions (1%, 2%) were dispersed to the liquor of glass ionomer cements respectively as experiment groups, whereas the undyed glass ionomer cements were taken as control group. The setting time was measured in each group according to the occupation standard. The macro/micro surface topographical features of all the glass ionomer cement specimens were investigated. Meanwhile, water sorption and solubility were assessed. The compressive strength of the specimens was determined using a universal testing machine (Instron). The specimens were then attached to the dentin and the vertical section of the bonding interface between the glass ionomer cement and the dentin was observed using endodontic microscope. Shear bond strength and failure mode of the specimens were also determined.

    RESULTS AND CONCLUSION: (1) There was no significant difference in the setting time among groups. The appearance of the specimens in the experiment groups was chromatically different from those in the control group, whereas the microscopic surface morphology of the specimens were insignificantly different. (2) In comparison to the control group, incorporation of organic dye solutions to the glass ionomer cements increased the solubility (P < 0.05), but the water absorption showed no significant difference in all groups. (3) The compressive strength of the specimens that had been immersed in the artificial saliva for 1 and 7 days in all groups showed no significant difference. (4) The dyed specimens in the experiment groups were tightly bonded to the dentin and the boding interface was continuous with no obvious fractures, cracks and bubbles. Penetration into dentinal tubules of organic dye solutions was not observed. (5) The shear bond strength of the specimens that had been immersed in the artificial saliva for 7 days in all groups showed no significant difference. The failure modes of the specimens mainly included cohesive failure and mixed failure. Our findings reveal that the glass ionomer cements can be obviously stained by methylene blue, crystal violet and erythrosine at a concentration of 1% or 2%, whereas physicochemical and mechanical properties of the glass ionomer cements are less altered, indicating the dyed glass ionomer cements can be used during root canal therapy as a wall build-up material.

     

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    Three-dimensional finite element analysis of splinted crown restoration of molars with different implant platform positions
    Lin Yi, Tao Xian-fa, Wang Yi-bo, Ding Chao, Xing Jian-yu, Xu Ran, Shi Jiu-hui
    2018, 22 (26):  4123-4127.  doi: 10.3969/j.issn.2095-4344.0894
    Abstract ( 290 )   PDF (670KB) ( 212 )   Save

    BACKGROUND: Different adjacent alveolar crest heights result in different positions of implant platforms, but implant supported splinted crowns are generally implanted at the same level. To date, studies on different positions of two implants due to the severity of bone defects have not been well documented.

    OBJECTIVE: To investigate the stress distribution at the implant-bone interface of two implants with different implant platform positions and to analyze which method of dental restoration has more biomechanical advantages compared with single crown restoration.
    METHODS: We prepared four kinds of mandibular models with two same kinds of implants that had different positions of implant platforms. The height difference between implant platforms was 0, 1, 2, 3 mm. Finally eight models were obtained by combinatorial arrangement of splinted crown restoration or single crown restoration. The stress distribution at the implant-bone interface was analyzed by a three-dimensional finite element method.

    RESULTS AND CONCLUSION: From the nephogram of Von Mises stress distribution, there was no significant difference in the stress distribution of the crown restoration with different implant platform positions. The maximum equivalent stress of each model was concentrated in the cortical bone region of the neck of the implant. With the increase of the height difference of the implant platforms, the maximum equivalent stress did not increase significantly. Under an axial load, the maximum equivalent stress was ranked as follows: A1 < B1, A2 < B2, A3 > B3, A4 < B4, while under a lateral load, the maximum equivalent stress was ranked as follows: A1 > B1, A2 > B2, A3 > B3, A4 > B4. By comparing the eight models, we found that under the axial load, the stress distribution of implant supported single crown restoration was better than that of implant supported splinted crown restoration, and the optimal height difference was 2 mm. However, under the lateral load, the stress distribution of implant supported splinted crown restoration was better than that of single crown restoration.

    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

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    Compressive strength of three all-ceramic chairside CAD/CAM onlays
    Yu Lu-lu, Gu Wei-ping
    2018, 22 (26):  4128-4132.  doi: 10.3969/j.issn.2095-4344.0747
    Abstract ( 440 )   PDF (584KB) ( 151 )   Save

    BACKGROUND: The use of chairside computer aided design/computer aided manufacture (CAD/CAM) system is a convenient way to fabricate porcelain onlays that have been widely used in clinical practice. Different chairside CAD/CAM all-ceramic materials have different physical and chemical properties, which make a certain difficulty in clinical selection. There are few studies on compressive strength of chairside CAD/CAM porcelain onlays at home and abroad.

    OBJECTIVE: To investigate the fracture strength of onlay restorations with different chairside CAD/CAM all-ceramic materials.

    METHODS: Thirty onlay specimens of isolated teeth were prepared in the study. These specimens were randomly divided into three groups: CEREC Blocs group, IPS e.max CAD group and Lava Ultimate group. In each group, 10 specimens were randomized into two subgroups: bonding group (dual-curing resin adhesive) and unbonded group. Afterwards, these specimens were subjected to vertical compressive loading; the maximum force at fracture and patterns of failure were recorded.

    RESULTS AND CONCLUSION: (1) In these groups, the maximum fracture strength was (313.22±56.00) MPa for IPS e.max CAD bonding group; the minimum fracture strength was (15.85±5.20) MPa for CEREC Blocs unbonded group. The fracture strength of IPS e.max CAD was higher than that of the other five groups (P < 0.05). The fracture strength of the bonding group was greater than that of the unbonded group (P < 0.05). There was no significant difference in the fracture strength of the Lava Ultimate and CEREC Blocs groups. (2) In the unbonded group, only fractured porcelain pieces were detected. In the bonding group, fracture of porcelain pieces was often accompanied by tooth fractures. The tooth fracture rate of the bonding group was greater than that of the unbonded group (P < 0.05). There was no significant difference in the failure mode between all-ceramic materials (P > 0.05). (3) Under the condition of this study, the highest fracture strength was found with the IPS e.max CAD material in the three kinds of CAD/CAM all ceramic materials.

     

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    Design of a novel two-segment adjustable nano-hydroxyapatite/polyamide 66 artificial prosthesis based on Mimics measurements of CT scan data
    Chen Guang-hui, Cheng Li, Wang Jian, Huang Quan, Bai Guang-jian, Yin Meng-chen, Wei Hai-feng, Yang Cheng, Xiao Jian-ru, Liu Tie-long
    2018, 22 (26):  4133-4138.  doi: 10.3969/j.issn.2095-4344.0942
    Abstract ( 346 )   PDF (753KB) ( 135 )   Save

    BACKGROUND: Previous studies have shown that commonly used prostheses for spinal repair are prone to have stress shielding effects (nonunion and local bone resorption) due to their limited high elastic modulus and limited contact areas, which can lead to the failure of internal fixation over time.

    OBJECTIVE: To design a novel two-segment adjustable artificial vertebral body through the measurement of CT scan data of the vertebral body using Mimics software.
    METHODS: Sixty young and middle-aged male patients with lumbar CT scan data were included. Mimics software was used to extract the skeleton contour of L1-3 vertebrae and to measure the vertebral body height and the transverse diameter of the upper and lower end plates, sagittal diameter, sagittal and coronal concave angles. Based on the measured data, a new type of artificial vertebral body adjustably and anatomically fitting the vertebral endplate was designed.

    RESULTS AND CONCLUSION: There was no significant difference in the L1-3 height and sagittal diameter of the upper and lower endplates, and sagittal concave angle among all the cases. The transverse diameter of the upper endplate was significantly less than that of the lower endplate in the same vertebra (P < 0.05). A significant difference in the sagittal concave angle was also found (P < 0.05). Based on the measured vertebral height, sagittal diameter of the endplate and sagittal concave angle, a novel artificial vertebral body with adjustable height was designed. The new product made of nano-hydroxyapatite/polyamide 66 was composed of a top cover and a base. The height of the designed vertebral body could be controlled by bone cement injection via the side hole on the base. And it could be tightly integrated with the upper and lower endplates of the adjacent vertebral body, which is beneficial to promote the osseointegration. In conclusion, the two-segment adjustable artificial vertebral body has the advantages of reasonable design and convenient operation.

    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

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    Imaging changes of idiopathic scoliosis treated with bone morphogenetic protein 2 nanometer artificial bone implantation combined with chiropractic manipulation
    Li Lian-tai, Hu Hua, Wang Shu-jun, Xie Shuang-xi, Wang Jun-bo, Wang Li-xin
    2018, 22 (26):  4139-4143.  doi: 10.3969/j.issn.2095-4344.0926
    Abstract ( 428 )   PDF (614KB) ( 100 )   Save

    BACKGROUND: In recent years, chiropractic manipulation with bone morphogenetic protein 2 nanometer artificial bone has achieved ideal outcomes in idiopathic scoliosis patients. However, this conclusion needs to be further verified.

    OBJECTIVE: To investigate the effect and imaging features of chiropractic manipulation combined with bone morphogenetic protein 2 nanometer artificial bone implantation in patients with idiopathic scoliosis.
    METHODS: Eighty Idiopathic scoliosis children aged 9-16 years were divided into two groups. The control group (n=40) was treated with chiropractic manipulation. The treatment group (n=40) was treated with chiropractic manipulation combined with bone morphogenesis protein 2 nanometer artificial bone implantation. Chiropractic treatment was performed once every other day. Three months after treatment, X-ray was used to assess the Cobb angle of scoliosis and visual analogue scale was used to evaluate the pain.

    RESULTS AND CONCLUSION: (1) The visual analogue scale score and the Cobb angle of scoliosis were lower in both groups at 3 months after treatment than the baseline (P < 0.05). (2) At 3 months after treatment, the curative effect of treatment group was higher than that of control group (90% vs. 73 %, P < 0.05). The Cobb angles of the lumbar and thoracic vertebrae in the treatment group at 3 months after treatment were significantly lower than those of the control group [thoracic vertebrae (17.32±3.98)° vs. (19.27±4.23)°; lumbar vertebrae (18.21±3.12)° vs. (23.25±4.64)°, P < 0.05]. The visual analogue scale scores in the treatment group were significantly lower than those in the control group at 1, 2 and 3 months after treatment [treatment group (3.51±1.02), (1.15±0.57), (0.99±0.12) points; control group (5.01±1.31), (3.57±0.95) and (1.46±0.64) points, respectively; P < 0.05]. These findings suggest that the bone morphogenetic protein 2 nanometer artificial bone implantation combined with chiropractic manipulation can improve spinal function and relieve pain in patients with idiopathic scoliosis.

     

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    Construction of mesoporous silica as an inorganic nano-drug carrier and its bioactivity
    Liu Ying, Shi Wei, Gong Rui, Zhu Hong-ming
    2018, 22 (26):  4144-4149.  doi: 10.3969/j.issn.2095-4344.0935
    Abstract ( 434 )   PDF (887KB) ( 126 )   Save

    BACKGROUND: Numerous studies have addressed the construction of stimulating response drug transport systems based on the mesoporous silica platform; however, drug leakage is still inevitable in the control cycle.

    OBJECTIVE: To study the preparation and bioactivity of mesoporous silica (MS@FcAA/P@CD@RGD).
    METHODS: MCM-41 mesoporous silica nanoparticles were used as a release carrier of intracellular controlled drugs. In the channel, ferrocene and fluorescent probes were packaged, and reoccupied using beta-cyclodextrin, and integrin inhibitors RGD were used as targeted groups to synthesize mesoporous silica nanoparticles (MS@FcAA/P@CD@RGD). MTT assay was performed on human cervical cancer cell line HeLa and human breast cancer cell MCF-7 as target cells and control cells, respectively, to evaluate the cytotoxicity of mesoporous silica nano-drug carriers with different mass concentrations. The passaged HeLa cells were cultured in three groups: a medium containing phorbol ester (induced a large amount of H2O2 in cells)+MS@FcAA/P@CD@RGD, a medium containing dimethyl sulfoxide (removal of intracellular H2O2)+MS@FcAA/P@CD@RGD, or a medium containing MS@FcAA/P@CD@RGD. Then the particle size was measured by Laser scanning confocal microscope, and the response of the nano-drug delivery system to intracellular H2O2 was assessed at 3 days after culture.

    RESULTS AND CONCLUSION: When the mesoporous silica nanoparticles were within the concentration of 10-100 mg/L, over 85 % of the cells were alive. Compared with the cells cultured in the medium containing MS@FcAA/P@CD@RGD, the fluorescence intensity of HeLa cells with phorbol ester were significantly increased, while the fluorescence intensity of HeLa cells with dimethyl sulfoxide were significantly reduced. To conclude, mesoporous silica nanoparticles have a low cytotoxicity, and have certain response to endogenous hydrogen peroxide.

     

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    Preparation of bacterial cellulose dressing and its effect on accelerating wound healing
    Xu Ling-hua, Jiang Xiao-mei, Bao Su-min, Hu Xue-feng, Liu Quan, Wu Bo, Xiao Ying, Li Jing
    2018, 22 (26):  4150-4155.  doi: 10.3969/j.issn.2095-4344.0923
    Abstract ( 429 )   PDF (883KB) ( 174 )   Save

    BACKGROUND: There are various wound dressings with their own merits and demerits in the market. Increasing studies have confirmed the feasibility of bacterial cellulose as wound dressing, while few reports has been published to compare bacterial cellulose with other kinds of wound dressings in promoting wound healing.

    OBJECTIVE: To study the wound healing effect of bacterial cellulose wound dressing (BC-HEC-1) in comparison with gauze and hydrocolloid in rats.
    METHODS: BC-HEC-1 was sterilely prepared by Gluconacetobacter xylinus fermenting followed by a series of process steps. The cytotoxicity, moisture content and pH were examined. In addition, the component and surface morphology of BC-HEC-1 were examined by infrared spectroscopy and scanning electron microscope respectively. Sprague-Dawley rats were anesthetized and a 2 cm×2 cm skin wound was made in each rat by sterile surgery. All the animals were thereafter divided into three groups (n=20 per group): gauze group, hydrocolloid group and BC-HEC-1 group, wrapped with the corresponding dressing, respectively. The dressing in each group was changed every day. Wound area was calculated by measuring wound length and width every other days after surgery. Wound samples from each rat were taken for histological observation at 4, 7, 14, 21 days after surgery. Meanwhile, serum levels of transforming growth factor beta 1 and platelet-derived growth factor were detected.

    RESULTS AND CONCLUSION: BC-HEC-1 was proved to have good hydrophilic property and no cytotoxicity. The water content was between 95%-98% and the pH was 6.5. The structure of BC-HEC-1 was identified by the infrared spectrum. Scanning electron microscope results showed that BC-HEC-1 is a nanoscale biomaterial. Compared with the traditional gauze dressing and hydrocolloid dressing, BC-HEC-1 wound dressing significantly increased the wound healing rate at 4-14 days after surgery (P < 0.05), and showed better moisturizing and anti-sticking effect as well as smaller wound area. The wound healing rate in the BC-HEC-1 group was significantly higher than that in the gauze and hydrocolloid groups at 4-14 days after surgery. The serum level of platelet-derived growth factor in the BC-HEC-1 group was also significantly increased compared with the gauze and hydrocolloid groups at 7 days after surgery (P < 0.05). Histopathological observation indicated BC-HEC-1 could promote the granulation tissue growth moderately and orderly, while the granulation tissues in the other groups had relative thin thickness, loose structure, and irregular arrangement. In conclusion, the BC-HEC-1 can effectively promote wound healing, and meanwhile, it shows better moisturizing effects.

    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

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    Suturing and bonding for repair of annulus fibrosus defects in goats
    Wang Yu-peng, Yin He-ping, Wu Yi-min, Li Shu-wen, Du Zhi-cai, Bai Ming, Meng Ge-dong
    2018, 22 (26):  4156-4161.  doi: 10.3969/j.issn.2095-4344.0859
    Abstract ( 334 )   PDF (823KB) ( 114 )   Save

    BACKGROUND: At present, there is a lack of effective strategies that deal with annulus fibrosus defects in a majority of cases undergoing lumbar discectomy, which is one of the important causes of postoperative relapse of lumbar disc herniation.

    OBJECTIVE: To explore the effects of direct suturing and medical fibrin bonder for annulus fibrosus defects in goats undergoing resection of intervertebral discs.
    METHODS: L1/2-L6/7 samples (36 lumbar vertebrae) from six goats aged 6 months were randomized into three groups (n=12 per group): direct suture group, bonding group and control group (with no intervention). An annular incision of 4 mm in length was made on the disc using a circle cutter. A small amount of nucleus pulposus (about 0.1 g) was taken from each sample followed by direct suturing, bonding and no treatment in corresponding groups. X-ray and MRI observation of the lumbar vertebra was performed preoperatively and 12 weeks postoperatively. Height index of the lumbar intervertebral disc (DHI) was calculated to evaluate the lumbar degeneration. The goats were sacrificed at 12 weeks postoperatively and the defect sites were observed using light microscope and transmission electron microscope.

    RESULTS AND CONCLUSION: The DHI values in three groups at 12 weeks postoperatively were ranked as follows: direct suturing group > bonding group > control group. Lumbar T2WI MRI modified Pfirrmann grade was ranked as follows: direct suturing group < bonding group < control group. Histological Masuda degeneration grade was ranked as follows: direct suturing group < bonding group < control group. Performance of cell ultrastructure at repair site was ranked as follows: direct suturing group > bonding group > control group. To conclude, both direct suturing and fibrin bonder can effectively repair annulus fibrosus defects, and moreover, direct suturing is superior to bonding in the repair effect.

    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

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    Surgical errors and complications due to induced membrane technique: an analysis of 44 cases of infected bone defects
    Zhou Zi-hong, Feng De-hong, Xu Ke-lin, Yin Qu-dong
    2018, 22 (26):  4162-4167.  doi: 10.3969/j.issn.2095-4344.0915
    Abstract ( 181 )   PDF (719KB) ( 180 )   Save

    BACKGROUND: There is a high incidence of complications in the treatment of infected bone defects by wrapped bone grafting using induced membrane.

    OBJECTIVE: To investigate how to reduce the surgical errors and complications of induced membrane technique.
    METHODS: Clinical data from 44 patients with infected bone defect treated with induced membrane technique were retrospectively analyzed. There were 29 males and 15 females, aged 14-69 years old. All patients were followed up for 15-51 months postoperatively. Forming way and quality of bone cement spacer, quality of induced membrane formed, concentration of antibiotics loaded, healing of incision and bony defect, complication and mobility of adjacent joints were observed.

    RESULTS AND CONCLUSION: (1) Bone cement spacer formed in vivo in 23 cases and in vitro in 21 cases. The quality of spacer formed was excellent in 14 cases, good in 17 cases, and poor in 13 cases. The induced membrane was of integrity in 22 cases, had small defects in 13 cases and had large defects in 9 cases. Concentration of vancomycin was low in 19 cases and moderate in 25 cases. Defects in the induced membrane were caused by small size of induced membrane formed which could not completely wrap the graft material in 13 cases and by the difficult removal due to the tight connection between the spacer and the broken end in 9 cases. (2) The clinical healing time was 3-16 months with an average of 5.9 months. The average frequency of operations using induced membrane technique until bone healing was 2.4 times. (3) There were 11 cases of complications, of which 8 cases were noted at 2 years prior to the use of induced membrane technique, 3 cases in the first stage (1 of incision disruption and superficial infection, 1 of deep infection, and 1 of flap necrosis, and 8 cases in the second stage (2 of nonunion, 5 of recurrence of infection, and 1 of malunion). (4) The range of movement of adjacent joints at the last follow-up was excellent in 24 cases, good in 11 cases, fair in 7 cases and poor in 2 cases, with the excellent and good rate of 80%. These findings indicate that the induced membrane technique is an effective method for infected bone defects. However, the presence of a learning curve is prone to cause surgical errors. Surgeons should master the surgical skills, especially the skills of spacer making, so as to avoid surgical errors, reduce complications and improve the effectiveness of treatment.

    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

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    Preparation, release and antitumor properties of sodium alginate/layered double hydroxides-5- fluorouracil delivery system
    Han Xiao-jing, Yang Hong, Sun Xiao-yu, Wang Hui, Wang Qing-feng
    2018, 22 (26):  4168-4173.  doi: 10.3969/j.issn.2095-4344.0943
    Abstract ( 404 )   PDF (1704KB) ( 224 )   Save

    BACKGROUND: In clinical practice, 5-fluorouracil (5-Fu) has disadvantages such as high toxicity and short metabolism time.

    OBJECTIVE: To prepare the sodium alginate (SA)/layered double hydroxides (LDH)-5-Fu delivery system and to explore its drug loading, micromorphology, in vitro release and inhibitory effect on hepatoma cells.
    METHODS: LDH-5-Fu solution and SA solution were mixed at a ratio of 3:5, 4:5 and 5:5 to prepare SA/LDH-5-Fu beads using ionic gel method, respectively. The drug loading capacity of these beads was then tested. SA/LDH-5-Fu beads were placed in PBS of pH=2.1, 4.6, and 7.4, and the release rate of 5-Fu was measured periodically. SMMC-7 721 hepatoma cells were cultured with the SA at different concentrations  (5, 10, 20, 40 mg/L), LDH-5-Fu beads, and SA/LDH-5-Fu bead suspension for 24 hours, and then the cell inhibitory rate was detected.

    RESULTS AND CONCLUSION: The drug loading rate of SA/LDH-5-Fu at 3:5, 4:5, and 5:5 was (3.09±0.08)%, (4.55±0.10)%, and (5.47±0.14)%, respectively. The release of 5-Fu from the SA/LDH-5-Fu beads at pH=2.1 and 4.6 was faster than that at pH=7.4. Moreover, the release of 5-Fu was gradually fastened with the increasing input amount of 5-Fu. SA showed little inhibition effect on SMMC-7721 cells, while the inhibitory rate of LDH-5-Fu or SA/LDH-5-Fu to SMMC-7721 in vitro was gradually increased, and the inhibitory rate of SA/LDH-5-Fu was significantly higher than that of LDH-5-Fu. These findings reveal that SA/LDH-5-Fu is a potential pH sensitive anti-tumor drug release system.  

     

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    Arthroscopic reconstruction for acute and chronic anterior cruciate ligament injuries using autologous or allogeneic tendon graft: an evaluation of reconstruction effects
    Xiang Shan-shan, Fu Ming, Zhang Zhi-qi, Yang Zi-bo, Chen Zhong-xian
    2018, 22 (26):  4174-4178.  doi: 10.3969/j.issn.2095-4344.0939
    Abstract ( 235 )   PDF (532KB) ( 111 )   Save

    BACKGROUND: Therapeutic efficacy on acute and old injuries of the anterior cruciate ligament treated with arthroscopic autologous or allogenic tendon has not yet been well studied.

    OBJECTIVE: To analyze the effect of arthroscopic reconstruction for acute and chronic anterior cruciate ligament injury using autologous or allogeneic tendon graft, and to discuss the clinical effectiveness of different implant materials at different reconstruction time.
    METHODS: We collected 105 patients who received arthroscopic reconstruction for anterior cruciate ligament injury, and divided them into four groups according to different injury time and implant materials: acute autograft group (acute injury+autologous tendon, 25 cases); acute allograft group (acute injury+allogeneic tendon, 7 cases); old autograft group (old injury+autologous tendon, 55 cases); old allograft group (old injury+ allogeneic tendon, 18 cases). Lysholm scores were used to test patient’s knee function before and after surgery. The follow-up time was 70 months

    RESULTS AND CONCLUSION: There was a significant improvement in the knee function at 70 months after surgery, and the Lysholm scores of each patient was significantly increased as compared with the baseline (P < 0.05). We did the further analysis of single factor effects and found that the Lysholm score in the acute autograft group was significantly high than that in the acute allograft group (P < 0.05). Therefore, early reconstruction using arthroscopic autologous tendon is of clinical benefit for anterior cruciate ligament injuries to restore the knee function.

     

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    Tissue-engineered skin for skin wound repair: construction by human acellular dermal matrix combined with bone marrow mesenchymal stem cells
    Chi Kai, Wu Lei, Chen Long-jin, Li Yong-lin
    2018, 22 (26):  4179-4183.  doi: 10.3969/j.issn.2095-4344.0889
    Abstract ( 400 )   PDF (757KB) ( 172 )   Save

    BACKGROUND: A variety of seed cells and scaffolds can be used for constructing tissue-engineered skin. Exploring a proper construction method is a hot topic of research.

    OBJECTIVE: To explore the feasibility of tissue-engineered skin to promote healing of skin wounds in rats.
    METHODS: Sprague-Dawley rats of 6-8 weeks old were taken to isolate bone marrow mesenchymal stem cells (BMSCs) using the whole bone marrow adherent method. Then, BMSCs were cultured and purified in vitro. Human foreskin samples were digested using enzyme digestion method to make human acellular dermal matrix (ADM). Tissue-engineered skin was thereafter constructed using BMSCs as seed cells and ADM as the scaffold, to cover the skin defect wound in the rats. Skin wound covered with ADM and nothing was used as ADM and blank control groups, respectively. Wound healing time was recorded and wound closure index was calculated. Evaluation of wound healing was conducted through hematoxylin-eosin, CK19 and BrdU immunohistochemical staining of wound samples at 2 weeks after transplantation.

    RESULTS AND CONCLUSION: The wound closure indexes in the three groups were ranked as follows: tissue-engineered skin group > ADM group > blank control group, and there were significant differences between groups (P < 0.05). The wound healing time was shortest in the tissue-engineered skin group, shorter in the ADM group and longest in the blank control group, and there were also significant differences between groups (P < 0.05). Cells positive for BrdU were detected in the tissue-engineered skin group, and the expression level of CK19 was significantly higher in the tissue-engineered skin group as compared with the other two groups. In conclusion, the tissue-engineered skin constructed by BMSCs and ADM achieves good outcomes in the repair of full-thickness skin wound.

    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

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    Effect of calcium phosphate coatings on corrosion resistance and biocompatibility of magnesium alloy scaffolds
    Ma Fei, Li Xiang, Xie Rui-min, Wang Yong-ping, He Yao-hua
    2018, 22 (26):  4184-4190.  doi: 10.3969/j.issn.2095-4344.0914
    Abstract ( 247 )   PDF (889KB) ( 150 )   Save

    BACKGROUND: Magnesium alloy has better biocompatibility and can accelerate growth of osteoblasts, but its  clinical use is limited because of a high corrosion rate in the physiological environment.

    OBJECTIVE: To explore the effect of calcium phosphate coating (Ca-P coating) on corrosion resistance and biocompatibility of AZ31 magnesium alloy scaffolds.
    METHODS: Using chemical vapor deposition, Ca-P coating was prepared on the surface of AZ31 magnesium alloy scaffolds. (1) Immersion test in static state: AZ31 magnesium alloy scaffolds with or without Ca-P coating were independently immersed in the DMEM medium and the material corrosion rate of each scaffold was tested at 10, 20 and 30 days after immersion. (2) Cytotoxicity test: MC3T3-E1 cells were cultured in the extracts of AZ31 magnesium alloy scaffolds with 100%, 75%, 50% and 25% Ca-P coatings, and cell proliferation and toxicity grade were determined at 1, 3, 5 days after culture. (3) Cell adhesion assay: MC3T3-E1 cells were separately seeded onto the surface of AZ31 magnesium alloy scaffolds with or without Ca-P coating, and cell number was counted at 6, 12 and 24 hours after culture. (4) Cell proliferation test: MC3T3-E1 cells were separately seeded onto the surface of AZ31 magnesium alloy scaffolds with or without Ca-P coating, and cell number was counted at 1, 3, 5 days after culture. (5) Aggregation test of blood cells: AZ31 magnesium alloy scaffolds with or without Ca-P coating were immersed in anticoagulant rabbit blood samples, and amounts of red blood cells, white blood cells and platelets were determined at 8 minutes after immersion.

    RESULTS AND CONCLUSION: (1) The corrosion and toxicity rate of AZ31 magnesium alloy scaffold with Ca-P coating was lower than that without Ca-P coating (P < 0.05) without coatings. (2) Cell toxicity of AZ31 magnesium alloy scaffolds with Ca-P coatings of different concentrations was grade 0 to 1. (3) The number of cells adherent to the surface of AZ31 magnesium alloy scaffolds with Ca-P coating was significantly higher than that without Ca-P coating at 12 and 24 hours after inoculation (P < 0.05). (4) The number of cells cultured in the extract of AZ31 magnesium alloy scaffolds with Ca-P coating was significantly higher than that cultured in the extract of the scaffold without Ca-P coating at 3 and 5 days after culture (P < 0.05). (5) The number of red blood cells, white blood cells and platelets in the scaffolds with or without Ca-P coating has no difference (P < 0.05). To conclude, Ca-P coating not only slows the corrosion rate of AZ31 magnesium alloy scaffolds, but also improves the scaffold biocompatibility.

     

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    Characterization of the cross-structure and composition of crucian fish scales
    Duan Ting-ting, Wang Ji-hui, Guo Yan, Xu Xing-ya, Wang De-gong, Zheng Wei, Huang Yu-song, Li Ning,Wang Ling, Xin Pei-xun
    2018, 22 (26):  4191-4195.  doi: 10.3969/j.issn.2095-4344.0949
    Abstract ( 514 )   PDF (791KB) ( 360 )   Save

    BACKGROUND: Fish scales have become the focus of research because of their ultra-light and excellent toughness.

    OBJECTIVE: To characterize the cross-scale structure and composition of fish scales.
    METHODS: The fresh fish scales were cleaned with deionized water. The samples were then examined by light microscopy, scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermal analysis.

    RESULTS AND CONCLUSION: (1) Under the light microscope, the outer surface of the fish scale was rough, and the whole structure was divided into two parts, covering area and exposed area. The fish scale presented with an irregular hexagonal state, and arranged in the form of a cover tile on the fish body surface to form a microscopic corrugated surface structure. (2) Under the scanning electron microscope, the cross-section was roughly divided into five layers, the third and fourth layers were in the fiber state, and the first, second and fifth layers were the dense layers. The main elements of the first three layers were carbon, oxygen, phosphorus and calcium. The fourth layer was mainly made up of carbon, oxygen and nitrogen, and contained a little amount of other elements. The fifth layer contained only carbon and oxygen. (3) The infrared spectrum analysis results showed that the outer surface of fish scales was mainly inorganic, and the inner surface was mainly organic, except for a few inorganic components. (4) X-ray diffraction analysis showed that the fish scale was mainly composed of organic components, and the spectrum showed no peak of inorganic components. After properly treated, the inorganic components of the fish scales were mainly hydroxyapatite. (5) Thermal analysis results showed that the main component of fish scales was organic matter. All these findings reveal that the fish scale is a layered composite structure composed of organic collagen and inorganic hydroxyapatite, which gives the fish scales excellent toughness, and therefore, the fish scale can effectively protect the body from being attacked and damaged. 

     

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    Effects of three surface roughening treatments on adhesion and flexural strength of zirconia ceramics: which one is better?
    Wang Ji-de, Deng Jiu-peng, Shen Bao-lian, Ma Li-juan
    2018, 22 (26):  4196-4201.  doi: 10.3969/j.issn.2095-4344.0937
    Abstract ( 329 )   PDF (737KB) ( 178 )   Save

    BACKGROUND: The surface roughening technology of zirconia ceramics is currently a hot spot in dental  restoration research. Commonly used surface roughening methods mainly include mechanical treatment and strong acid corrosion, both of which are highly destructive. Previous studies on surface roughening often ignore its influence on the flexural strength of zirconia that has good mechanical properties.

    OBJECTIVE: To investigate the effects of three different surface roughening methods on the flexural strength and shear bond strength of zirconia, thereby seeking a roughening method that effectively increase the shear bond strength but produce little effect on the flexural strength of zirconia.
    METHODS: Two classes of zirconia specimens, class I (15 mm×3 mm×1 mm, n=40) and class II (3 mm×3 mm×3 mm, n=40), were prepared. Class I specimens were randomly divided into four groups (n=10 per group): blank control, sandblasting with 110 μm Al2O3 particles, Er:YAG laser treatment, and hot-etching. Class I specimens were used for three-point bending test to detect the flexural strength of zirconia. Class II specimens received the same treatments with class I, and then bonded to the isolated teeth (treatment agent: Monobond N; adhesive agent: PULPDENT embrace resin cement). Then, these specimens were stored in distilled water at 37 oC for 24 hours, and the shear bond strength was measured.

    RESULTS AND CONCLUSION: (1) The mean flexural strength of class I specimens was 939.86 MPa in blank control group, 841.38 MPa in sandblasting group, 739.32 MPa in Er:YAG laser and 746.82 MPa in hot-etching group. There was no statistically significant difference between Er:YAG laser group and hot-etching group (P > 0.05), but the difference between other groups was statistically significant (P < 0.05). (2) The mean shear bond strength of class II specimens was (7.00±0.67) MPa in blank control group, (11.73±1.31) MPa in sandblasting group, (8.75±0.92) MPa in Er:YAG laser group and (12.05±1.05) MPa in hot-etching group. There was no statistically significant difference between Er:YAG laser group and hot-etching group (P > 0.05), but the difference between other groups were statistically significant (P < 0.05). (3) Under the scanning electron microscope, the specimen surface was smooth and flat in the blank control group. Obvious hollows were formed on the surface in the sandblasting group, mostly of which were strip-shaped, and a few of which were round-shaped. Etched lines and dot-like pits formed made the zirconia surface rough and uneven in the Er:YAG laser group. A three-dimensional network structure of the zirconia block with intergranular porosity was observed in the hot-etching group. (4) The volume percent of the monoclinic phase crystal form on the specimen surface was 0.91% in the blank control group, 12.50% in the sandblasting group, 6.64% in the Er:YAG laser group, and 17.81% in the hot-etching group. To conclude, the three kinds of surface roughening treatments could improve the shear bond strength of zirconia to resin cement and reduce the flexural strength. Considering synthetically, 110 μm alumina blasting is an ideal roughening treatment by synthetically considering operating convenience, flexural strength and shear bond strength.

    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

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    Degradability of poly(trimethylene carbonate) in vitro
    Zhang Wei, Li Hong-yuan, Yang Li-qun, Li Miao, Jin Ying, Yi Dong-xu
    2018, 22 (26):  4202-4207.  doi: 10.3969/j.issn.2095-4344.0944
    Abstract ( 265 )   PDF (756KB) ( 126 )   Save

    BACKGROUND: At present, the fallopian tube embolization devices have many malpractices because of the metal texture. Poly(trimethylene carbonate), a biodegradable material, is introduced to find a breakthrough in the field of tubal embolism materials.

    OBJECTIVE: To observe the degradation behavior of poly(trimethylene carbonate) and to demonstrate the possibility of its use as a tubal embolization material.
    METHODS: Poly(trimethylene carbonate) with different relative molecular weight was soaked in phosphate buffer and lipase solution at 37 oC with gently shaking. The degradation behavior of poly(trimethylene carbonate) was evaluated by observing the morphology, mass loss, relative molecular weight of the samples and the pH value of the degradation solution regularly.

    RESULTS AND CONCLUSION: Poly(trimethylene carbonate) exhibited surface erosion degradation in vitro and the degradation products did not contain acid compounds. Lipase could accelerate the degradation process, but the shape and size of the samples were the main factors that affected the decline rate of molecular weight. The molecular weight of the samples affected the degradation rate and dimensional stability: the larger the relative molecular weight, the higher shape retention rate, but the faster mass loss; the smaller the relative molecular weight, the slower mass loss, but the more serious deformation. Therefore, poly(trimethylene carbonate) is expected to be used for fallopian tube embolization materials by selecting suitable molecular weight or adjusting its properties by copolymerization.

     

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    Irradiation with erbium, chromium:yttrium scandium gallium garnet laser alters shear bond strength to primary tooth dentin
    Liang Yun, Shi Jian-jie, Chen Ke, Luo Zhen-shan, Deng Wen-xin
    2018, 22 (26):  4208-4214.  doi: 10.3969/j.issn.2095-4344.0933
    Abstract ( 406 )   PDF (1045KB) ( 119 )   Save

    BACKGROUND: Pretreatment of dental hard tissues is critical for a success in tooth bonding repair.

    OBJECTIVE: To explore the shear bond strength of nano-hybrid resin bonded to the primary tooth dentin after conditioning by 35% phosphoric acid, erbium, chromium:yttrium scandium gallium garnet (Er,Cr:YSGG) irradiation or their combined use.
    METHODS: 120 extracted primary incisors with enamel removal were randomly divided into three groups and dealt with the following pretreatments: in control group (n=12), the tooth surface was without any processing; in acid etching group (n=12), the tooth surface was etched using 35% phosphoric acid; in laser group (n=48), the tooth surface was treated by Er,Cr:YSGG laser at four power outputs (1 W,   50 mJ, 20 Hz; 2 W, 100 mJ, 20 Hz; 3 W, 150 mJ, 20 Hz; 4 W, 200 mJ, 20 Hz); in combined group (n=48), the tooth surface was treated with 35% phosphoric acid followed by Er,Cr:YSGG laser irradiation at four power outputs (1 W, 50 mJ, 20 Hz; 2 W, 100 mJ, 20 Hz; 3 W, 150 mJ,  20 Hz; 4 W, 200 mJ, 20 Hz). Two samples from each group were randomly selected and observed using scanning electron microscope, and the residual samples were bonded with the composite resin for shear bonding strength test.

    RESULTS AND CONCLUSION: (1) The shear bond strength of the dentine was lowest in the control group [(4.03±1.80) MPa], and highest in the 2 W laser group [(14.12±3.23) MPa], followed by the acid etching group [(13.11±3.23) MPa]. (2) Under the scanning electron microscope, the dentin surface of the control group was covered with a smear layer and debris. Dentin tubule of the acid etching group completely opened, with increased pipe diameter, the smear layer was removed presenting with the smooth surface on which only a little debris was seen, and no marked boundary existed between the pertitubular dentin and intertubular dentin. The dentin surface in the laser group was rugged and presented with fish scale-shaped flakes, the dentin tubule opened, and the intertubular dentin seemed to ablate more than the pertitubular dentin, showing a cuff-like protrusion of the dentinal tubules without smear layer. As the laser energy improved, blocking of the dentin tubule occurred, and some cracks and fractures appeared on the dentin surface. Fluctuant dentin surface was detected in the combined group, in which overall demineralization was higher and embolism and clogging of the dentin tubule was more prominent compared with the laser group. Overall, Er,Cr:YSGG laser ablation of the primary teeth, prior to the adhesive protocol, influences the shear bond strength to the primary tooth dentin and the best parameters for Er,Cr:YSGG laser are 2 W, 20 Hz, 100 mJ.

    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

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    Biopolymer materials for cartilage tissue engineering
    Feng Nai-bo, Chang Fei, Han Yu, Wang Xin
    2018, 22 (26):  4215-4221.  doi: 10.3969/j.issn.2095-4344.0787
    Abstract ( 202 )   PDF (767KB) ( 132 )   Save

    BACKGROUND: Biopolymer materials have unique advantages in cartilage tissue engineering, which have become an increasing concern in cartilage repair.

    OBJECTIVE: To summarize the application of biopolymer materials in cartilage tissue engineering in recent years.
    METHODS: The first author retrieved PubMed, ScienceDirect and Medline databases for relevant articles published from January 2000 to June 2017. The key words were “cartilage defect, biopolymer” in English. Initially, 305 articles were retrieved, and finally 72 articles were included in result analysis.

    RESULTS AND CONCLUSION: Commonly used polymer compounds are classified into natural materials (including natural polymer proteins, polysaccharides and polynucleotides) and synthetic materials (including polylactic acid, polyethylene glycol, polyvinyl alcohol). The multilayer scaffold technology is one of the application innovations of biopolymer materials. This scaffold is consistent with the natural cartilage in the structure, on which newborn cartilage tissues develop similar biomechanical properties, mechanical strength and shear resistance to normal cartilage. Biopolymer scaffolds and hydrogels can load stem cells and cytokines and exert a synergistic repair of cartilage defects, which have achieved desired repair results. Despite limitations in clinical practice, biopolymer materials will surely become a hot issue in cartilage repair.

     

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    Tissue-engineering scaffolds: characteristics and applications in tissue engineering
    Ge Zhen, Zou Gang, Liu Yi, Zhang Jun, Li Yu-wan, Dong Li-ming
    2018, 22 (26):  4222-4228.  doi: 10.3969/j.issn.2095-4344.0936
    Abstract ( 380 )   PDF (758KB) ( 112 )   Save

    BACKGROUND: Scaffold materials act as a key factor in tissue engineering. Seed cells adhered onto the scaffold are induced to proliferate and differentiate into specific cells under certain conditions, so as to promote tissue damage repair.

    OBJECTIVE: To review the advantages and disadvantages of different scaffold materials, including natural materials, biodegradable materials and composite materials, and their applications in the tissue engineering in recent years, and to highlight the application of graphene composite scaffolds in tissue engineering.
    METHODS: We searched the databases of CNKI, PubMed, Elsevier ScienceDirect, Engineering Village, and Web of Science to retrieve the relevant articles published from 1990 to 2018 with the key words of “tissue engineering; ligament; scaffold material; biodegradable material; composite materials; progress in research” in Chinese and English, respectively. After initial screening, eligible articles were further summarized and analyzed.

    RESULTS AND CONCLUSION: Commonly used scaffolds for tissue engineering include natural materials, biodegradable materials, and composite materials. These materials are now widely used in the tissue engineering involving bone, cartilage, ligaments, and skin. Most of the natural materials are non-toxic, biocompatible, have good cell affinity and can be completely absorbed. However, their disadvantages are poor mechanical strength. Biodegradable materials have the advantages of good biodegradability, tissue compatibility, biocompatibility, and no cytotoxicity, but also have some disadvantages—strong hydrophobicity and poor cell adhesion. Graphene has good stability, electrical conductivity, thermal conductivity, and mechanical strength, but it is difficult to shape due to its thin texture. Furthermore, poor biocompatibility and water solubility are also its drawbacks. Composite materials are designed to integrate the characteristics of different single materials to produce more comprehensive features. Therefore, composite scaffold materials have become the focus of current tissue engineering research.

    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

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    Preparation and research progress of long-circulating and pH-sensitive liposomes containing cisplatin
    Shi Wei, Lu Ying, Gong Rui
    2018, 22 (26):  4229-4234.  doi: 10.3969/j.issn.2095-4344.0945
    Abstract ( 243 )   PDF (709KB) ( 156 )   Save

    BACKGROUND: Although cisplatin is a widely used anticancer agent with a high antitumor activity, its clinical use is limited due to its severe side effects. Liposomes can avoid toxicity to normal cells by using both passive and active targeting strategies, and thus enhance the intracellular concentration of drugs in cancer cells.

    OBJECTIVE: To review the preparation and application of long-circulating and pH-sensitive liposomes containing cisplatin.
    METHODS: The authors retrieved the articles about the preparation of long-circulating and pH-sensitive liposomes containing cisplatin in in WanFang, Elsevier and PubMed databases by the keywords as follows: “long-circulating; pH-sensitive liposomes containing cisplatin; nanocarriers; treatment of tumors; biological toxicity” in Chinese and English, respectively.

    RESULTS AND CONCLUSION: At present, long circulating and pH-sensitive liposomes containing cisplatin are mainly prepared by freeze-thaw and dehydration-rehydration and reverse-phase evaporation. However, reverse-phase evaporation has been proved to be the most suitable method, which can be used to prepare small-size liposome carriers, and the purified long-circulating and pH-sensitive liposome containing cisplatin is finally produced. The long-circulating and pH-sensitive liposome containing cisplatin improves the pharmacokinetics of cisplatin, reduces the biological toxicity, and can localize tumor cells. In the mouse model of pancreatic tumor, this new nano-scaled drug delivery system has obvious advantages compared with the traditional method of cisplatin intravenous administration, which shows a great prospect in the future application of antitumor therapy.

    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

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    Physical guidance cues of nerve conduits
    Xiang Yang, Wu Yi-bing, Wei Peng, Yin Jun, Dai Guang-li
    2018, 22 (26):  4235-4240.  doi: 10.3969/j.issn.2095-4344.0764
    Abstract ( 438 )   PDF (698KB) ( 124 )   Save

    BACKGROUND: A tissue-engineered nerve conduit for peripheral nerve repair is a popular alternative to peripheral nerve repair recently. Adding various physical guidance cues result in better outcome of regeneration of defected nerve.

    OBJECTIVE: To conclude the physical guidance cues in two aspects, including conduit luminal wall property and intralluminal guidance structures.
    METHODS: We searched WanFang database and Web of Science database for relevant literature published from 1980 to 2017 using the keywords of “tissue engineering; nerve conduit; peripheral nerve; injury; scaffold; topological cues” in Chinese and English, respectively.

    RESULTS AND CONCLUSION: Autograft and allograft are two main methods for peripheral nerve repair, but both of them have some inescapable disadvantages. Tissue-engineered nerve conduit as a scaffold bridging the nerve gap overcomes the above-mentioned disadvantages. In relative experiments, the introduction of physical guidance cues to the nerve conduit is proved to improve nerve regeneration. If physical guidance cues within nerve conduit achieve an optimal balance, the tissue-engineered nerve conduit with the introduction of biochemical guidance cues will achieve optimal outcome in nerve regeneration, and thus it seems to be the first choice for peripheral nerve repair in the future.

     

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    Prevention and treatment of cement leakage in percutaneous vertebroplasty
    Yan Guang-hua, Ge Shun-jie, Qiu Ji-ren, Lu Mao-de
    2018, 22 (26):  4241-4246.  doi: 10.3969/j.issn.2095-4344.0780
    Abstract ( 271 )   PDF (732KB) ( 145 )   Save

    BACKGROUND: Percutaneous vertebroplasty is characterized by small surgical trauma and good analgesic effect, and it can also increase the strength and stability of the vertebral body. Therefore, it has been widely used in clinical practice. However, postoperative bone cement leakage is still at high incidence.

    OBJECTIVE: To summarize the prevention and treatment of cement leakage in percutaneous vertebroplasty.
    METHODS: We retrieved PubMed for relevant articles published from January 1999 to June 2017. The key words were “percutaneous vertebroplasty; bone cement leakage; prevention and treatment”. We also retrieved CNKI database for relevant articles published from May 2006 to July 2017, with the key words of “percutaneous vertebroplasty; bone cement leakage; prevention and treatment” in Chinese.

    RESULTS AND CONCLUSION: In order to reduce the occurrence of the leakage of bone cement, there are some cautions as follows: (1) perform a detailed preoperative examination and inquire the medical history; (2) perfect imaging examination;       (3) master the surgical indications and contraindications strictly; (4) choose the proper puncture path, and use C-arm perspective and communicate with patients during the operation; (5) use high-viscosity bone cement as much as possible, inject proper amount of bone cement in the dough consistency; and (6) pull the needle until a few minutes after the completion of the bone cement infusion. Cement leakage is asymptomatic in most cases, and some patients only feel local pain. Most patients can recur after the conservative treatment. Some catastrophic consequences, such as bone cement leakage via intervertebral pores, appear with the compression of the spinal cord and nerve, and conservative treatment cannot completely remove the compression. We should remove bone cement by open surgery if necessary. For serious complications such as pulmonary embolism and lower limb vein embolism, surgical treatments should be taken in the presence of unrelieved symptoms.

    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

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    Application of controlled-release nanoparticles in chemotherapy of bone tumors
    Ma Hong-yun, Zhuang Xin-ming, Kao Yan-bin, Wang Zhen-yu, Qu Zhi-gang, Song Qing-xu, Xu Wei-guo, Liu Yi
    2018, 22 (26):  4247-4252.  doi: 10.3969/j.issn.2095-4344.0733
    Abstract ( 219 )   PDF (846KB) ( 114 )   Save

    BACKGROUND: In recent years, controlled-release nanoparticles have become popular in the treatment of malignant tumors.

    OBJECTIVE: To summarize the applications and prospects of controlled-release nanoparticles in the treatment of bone tumors
    METHODS: By using “nanoparticles, controlled drug release, bone tumor or osteosarcoma or Ewing sarcoma” as keywords, we retrieved PubMed, Web of Science and NCBI for the articles published in the past 10 years about the research progress of controlled-release nanoparticles in the treatment of bone tumors.

    RESULTS AND CONCLUSION: Bone tumor is a malignant tumor with high morbidity and mortality, and seriously threatens the quality of life of human beings. Compared with traditional chemotherapeutic drugs, nanoparticles have the advantages of controlled release, synergistic treatment, crossing the biological barrier, targeted therapy, enhancing tumor accumulation and prolonging the circulation time. Controlled-release nanoparticles can target the complex microenvironment of bone tumors and enable targeting and precision control, which can minimize side effects and drug resistance of traditional chemotherapy. Our ultimate goal of research on controlled-release nanoparticles is to increase the penetration rate of nano-drugs at the tumor site and reduce the systemic toxicity while ensuring drug-loading rate, and to achieve the versatility of nano-drug treatments. We believe that the controlled-release nanoparticles with inherent advantages combined with intelligent and collaborative drug deliveries will play a considerable role in this interdisciplinary field.

    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

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    Bone tissue engineering scaffolds and bone repair materials: composite bone graft materials have a bright future in clinical practice
    Zhang Di-feng, Yu Xiao, Pang Qing-jiang
    2018, 22 (26):  4253-4258.  doi: 10.3969/j.issn.2095-4344.0732
    Abstract ( 237 )   PDF (785KB) ( 117 )   Save

    BACKGROUND: It is always a difficult problem for orthopedic surgeons to repair a bone defect caused by infection, tumor or congenital diseases. Most of these defects cannot heal without any aid of bone transplantation. Autogenous bone has been widely used in clinic because of its good bone conduction, bone induction and bone formation, but its use is limited by many conditions. As the core part of bone tissue engineering, scaffold materials have attracted much attention in the physical structure and function. Bone transplantation has also been widely used in plastic surgery, neurosurgery, and oral surgery.

    OBJECTIVE: To review the progress of bone repair materials.
    METHODS: The first author retrieved literatures on bone graft materials and bone defect repair published during 2006-2016 in CNKI (Medical Edition) database and Foreign Medical Journals Full-Text Service.

    RESULTS AND CONCLUSION: With the rapid development of multi-disciplinary disciplines, such as material science and molecular biology, multi-disciplinary integration and three-dimensional technology, and the application of nano-cell genetic engineering, composite bone graft materials have a broad prospect. A variety of bone graft materials with different merit and demerits have been developed. A proper repair material is necessary and urgent for the clinical treatment of bone defects, especially large or segmental bone defects. As for the most potential xenogeneic bone graft, further research is warranted to evaluate its clinical safety and effectiveness.

    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

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    Acellular tissue matrix in plastic surgery: research progress and clinical application
    Yang Mei-rong, Pan Bo, Zhao Bo
    2018, 22 (26):  4259-4264.  doi: 10.3969/j.issn.2095-4344.0762
    Abstract ( 334 )   PDF (710KB) ( 170 )   Save

    BACKGROUND: Acellular tissue matrix as a new biological material has been extensively used in plastic surgery with prominent therapeutic effects.

    OBJECTIVE: To review the characteristics of acellular tissue matrix and its clinical progress in plastic surgery.
    METHODS: A computer-based search of CNKI and PubMed was performed by the first author for relevant articles published from 1990 to 2017, using the key words of “acellular tissue matrix, plastic/cosmetic, burn, scar, breast, cartilage, cleft lip/palate, nose/nasal, eye/ophthalmic, lip” in Chinese and English, respectively. After screening, finally 53 articles were included in result analysis.

    RESULTS AND CONCLUSION: (1) Acellular tissue matrix has the following advantages: immune tolerance in bacterial infection and tissue regeneration. When implanted into humans, acellular tissue matrix can induce and promote migration, adhesion, proliferation and differentiation of surrounding cells to achieve tissue regeneration and structural remodeling. (2) Acellular tissue matrix has been widely used in plastic surgery, including burn repair, pathological scar, breast reconstruction, lip/palate cleft, ocular and nasal plastic surgery, and lip augmentation. Application of acellular tissue matrix in cartilage repair still remains in the stage of animal experiment. (3) Small intestinal submucosa is a potential filling material for plastic surgery in consideration of its low immunogenicity, good compatibility and high activity.

     

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