RÉSUMÉ
BACKGROUND:Col agen type II and proteoglycan loss are two most obvious manifestations of cartilage damage in the onset of osteoarthritis. Changes in col agen type II and proteoglycan as the main components of cartilage matrix directly lead to cartilage degeneration and subsequently result in osteoarthritis. How to reverse or prevent the development of this process becomes the focus of medical research. OBJECTIVE:To observe the effect of warming yang and benefiting marrow recipe on the expression of col agen type II and proteoglycan in the articular cartilage of knee osteoarthritis rabbits as wel as to further explore the mechanism underlying chondrocyte protection. METHODS:Ninety-six New Zealand rabbits, aged 9 months old, male and female, were selected to prepare osteoarthritis models in extension position using cast immobilization method, and were randomly divided into four groups:blank group (untreated), model group (simple modeling), Chinese medicine group (intragastric administration of extracts of warming yang and benefiting marrow recipe, 24 mL/kg/d) and western medicine group (intragastric administration of glucosamine hydrochloride, 24 mL/kg/d). Intragastric administration was done once a day for 6 weeks. RT-PCR technology was used to observe the effect of warming yang and benefiting marrow recipe on the expression of col agen type II and proteoglycans in the articular cartilage, and pathological examination was also done. RESULTS AND CONCLUSION:The cartilage surface was smooth in the blank group and Chinese medicine group, with uniform toluidine blue staining, but in the model group and western medicine group, the cartilage surface was rough and the toluidine blue staining was extremely uneven with obvious loss of surface and middle layer dying. The expressions of cartilage proteoglycan and col agen type II in the model group were significantly lower than those in the blank group (P<0.01) as wel as in the Chinese medicine group and western medicine group (P<0.05). In addition, the expressions of cartilage proteoglycan and col agen type II in the Chinese medicine group were higher than those in the western medicine group (P<0.05). These findings indicate that the recipe of warming yang and benefiting marrow can enhance the expressions of col agen type II and proteoglycan, which can maintain the normal col agen phenotype and protect the articular cartilage.
RÉSUMÉ
BACKGROUND:Matrix protein is an essential component of the vascular wal , provides a necessary frame for the integrity of the vessel wal and physiological function of vascular wal cel s, and regulates cel s and smooth muscle. OBJECTIVE:To construct rat model of early aneurysm, and to evaluate differences in the expression of matrix structural proteins during cerebral aneurysm formation. METHODS:Twenty-eight healthy male Sprague-Dawley rats were randomized into control group (n=8) and model group (n=20). Aneurysm model was established by ligation of the left common carotid artery and right renal artery-induced hypertension in the model group. In the control group, only the left carotid artery bifurcation and bilateral carotid were exposed in rats. Rats in the model group were sacrificed at 15 and 30 days after model establishment. Right anterior cerebral artery in rats and olfactory artery bifurcation received immunohistochemical staining. The expressions of fibronectin,α-smooth muscle actin and col agen III were analyzed. RESULTS AND CONCLUSION:Compared with the control group, no significant difference in fibronectin expression was detected in right anterior cerebral artery and olfactory artery bifurcation in rats of the model group at 30 days after model establishment (P>0.05). However,α-smooth muscle actin and col agen III expressions were significantly reduced (P<0.05). These data confirmed that expression of structural proteins had differences and dynamic changes during early aneurysm formation in rats. Degradation of matrix structural protein in cerebral artery may be one of the key mechanism of aneurysm formation.
RÉSUMÉ
BACKGROUND:Studies have shown that neural stem cells isolated from embryonic rat cerebral cortex can proliferate and differentiate into neurons, astrocytes and oligodendrocytes in col agen gels. OBJECTIVE:To investigate the effect of neural stem cells combined with col agen gel on the apoptosis of nerve cells in the brain of rats after spinal cord injury. METHODS:Forty-five spinal cord injury rat models were made through spinal cord hemisection and randomly divided into three groups. At 1 week after modeling, rats in the celltransplantation group were injected al ogeneic neural stem cellsuspension into the injured site, rats in the combination group were administered with al ogeneic neural stem cells/col agen gel suspension into the injured site, and rats in the model group received no treatment. RESULTS AND CONCLUSION:From 1 to 8 weeks after injury, the Basso, Beattie and Bresnahan (BBB) locomotion scores in the combination group were significantly higher than those in the other two groups (P<0.05). Hematoxylin-eosin staining showed that at 1 week after transplantation, there were a few necrotic cells and Bcl-2 positive cells, but a large amount of Bax positive cells in the three groups. Then, the number of Bax-and Bcl-2-positive cells was reduced gradual yin the three groups. At 8 weeks after transplantation, the number of Bax-positive cells was significantly higher in the model group than the other two group (P<0.05), but the number of Bcl-2-positive cells were dramatical y lower (P<0.05). Meanwhile, there were no necrotic cells in the three groups. These findings indicate that neural stem celltransplantation combined with col agen gel scaffold can arrest apoptosis of nerve cells in the brain of rats after spinal cord injury, and promote functional recovery after spinal cord injury.
RÉSUMÉ
BACKGROUND:Mesenchymal stem celltransplantation promoted skin repair in trauma via various regulatory mechanisms and inhibited scar formation. At present, many scholars believed that bioactive factors secreted by mesenchymal stem cells played an important role. OBJECTIVE:To investigate the effects of bone marrow mesenchymal stem cellconditioned medium on the proliferation and col agen synthesis of hypertrophic scar fibroblasts. METHODS:Human bone marrow mesenchymal stem cells and hypertrophic scar fibroblasts were isolated and cultured, and bone marrow mesenchymal stem cellconditioned medium was prepared. Hypertrophic scar fibroblasts were cultured in vitro with 12, 24, and 48 hour-col ected conditioned medium for 24 hours, which was compared with blank control group. The proliferation of cells was determined by CCK-8. Type I and type III col agen expression in hypertrophic scar fibroblasts was detected using real-time PCR. RESULTS AND CONCLUSION:Compared with the blank control group, 24 and 48 hour-col ected conditioned medium significantly inhibited the proliferation of hypertrophic scar fibroblasts (P<0.01), and also suppressed col agen synthesis of hypertrophic scar fibroblasts (P<0.01). Results suggested that bone marrow mesenchymal stem cellconditioned medium inhibited the proliferation and col agen synthesis of hypertrophic scar fibroblasts by secreting anti-fibrotic bioactive factors, which may provide new theoretical supports for celltherapy to reduce cutaneous scarring.
RÉSUMÉ
BACKGROUND:Experiments have shown that the col agen substrate has the capability of stimulating cartilage generation, but the stimulating role of different types of col agen substrates remains controversial. OBJECTIVE:To investigate the effect of type I and type II col agen on the biological characteristics of human chondrocytes cultured in vitro. METHODS:Human chondrocytes at passage were cultured onto the ordinary culture plates (ordinary plate), type I col agen-coated culture plates (type I plate), and type II col agen-coated culture plates (type II plate). cellgrowth curves were determined by MTT method after cells were cultured for 10 days. By ELISA, PCR, and 1,9-dimethyl methyleneblue technology, type I and type II col agen and glycosaminoglycan contents were quantitatively detected in cartilage cells 28 days after culture. RESULTS AND CONCLUSION:The number of cartilage cells was the highest in type II plate, which was twice of that in type I plate and five times of that in ordinary plate. Cartilage cells in type II plate secreted the least amount of type I col agen, which showed significant differences compared with the ordinary plate (P0.01). Cartilage cells in type II plate secreted the most amount of type II col agen and glycosaminoglycan, showing significant differences compared with the other two plates (P<0.01). The cartilage cells cultured in col agen plates are better than that cultured in ordinary culture plate, type II col agen culture plate is better than type I col agen culture plate in maintaining cellshape, extending the dedifferentiation pattern, and promoting celldifferentiation.
RÉSUMÉ
BACKGROUND:Bio-Gide col agen membranes show a good biocompatibility with stem cells. But the research on the osteogenetic differentiation of bone marrow mesenchymal stem cells cultured on the Bio-Gide col agen membranes is rarely reported. OBJECTIVE:To observe the effect of Bio-Gide col agen membranes on the proliferation and the osteogenetic differentiation of bone marrow mesenchymal stem cells. METHODS:Bone marrow mesenchymal stem cells from rabbits were isolated and cultured by using the whole bone marrow adherence method in vitro. Passage 3 bone marrow mesenchymal stem cells were selected and seeded on the Bio-Gide col agen membrane pretreated petri dish (experimental group) and simple petri dish (control group). The proliferation of bone marrow mesenchymal stem cells was detected by cellCounting Kit-8 at 1, 4, 7, 14 days. The supernatant of the cells cultured in osteogenic differentiation medium were col ected to detect the activity of alkaline phosphatase at 1, 4, 7, 14 days. RESULTS AND CONCLUSION:The number of bone marrow mesenchymal stem cells in the two groups was increased with the increasing time, and the control group had more cells than the experimental group at 7 days (P<0.05). There was no significant difference between the two groups at other time points. The alkaline phosphatase activity was increased with the increasing culture time, and the experimental group had a higher activity than the control group at 14 days (P<0.05). There was no significant difference between the two groups at other time points. Experimental findings indicate that Bio-Gide col agen membranes can promote the proliferation and the osteogenetic differentiation of bone marrow mesenchymal stem cells.
RÉSUMÉ
BACKGROUND:Studies have shown that Clematis chinensis Osbeck can promote articular chondrocyte proliferation, maintain and promote the synthesis of cartilage proteoglycan and type II col agen in chondrocytes. Low-intensity pulsed ultrasound can effectively improve the carticular chondrocyte proliferation, increase the cellmembrane permeability, and promote chemicals or genes delivery, so as to improve the biological effects of chemicals. OBJECTIVE:To observe the effect of low-intensity pulsed ultrasound mediated Clematis chinensis Osbeck on the proliferation of cartilage cells and the expression of type II col agen and transforming growth factor (TGF)-β1 of rabbit knee articular chondrocytes cultured in vitro, and explore the effect and mechanism of Clematis chinensis Osbeck mediated by low-intensity pulsed ultrasound on cartilage damage. METHODThe rabbit knee articular chondrocytes were isolated and cultured in vitro. cells of the second generation in logarithmic growth phase were randomly divided into four groupcontrol group, low-intensity pulsed ultrasound (LIPUS) group, Clematis chinensis Osbeck (CCO) group, and CCO+LIPUS group. After cells were cultured under different conditions for 3 days, cellproliferation was measured with cellCount Kit-8 assay. The secretion of type II col agen was detected by cytochemical staining method, and the expression of TGF-β1 was assayed by western blot analysis. RESULTS AND CONCLUSION:The number of cells in the other three groups were significantly higher than that in control group at 3 days after culture (P<0.05), while the CCO+LIPUS group had the most cells. Cytochemical staining showed that the area and absorbance value of type II col agen in cartilage cells were significantly increased in CCO+LIPUS group, compared with control group (P<0.05), and the difference with control group was larger than the amount of that of LIPUS group and CCO group with control group. Western blot analysis showed that TGF-β1 was significantly expressed in CCO+LIPUS group, and the relative gray value was significantly higher than the other groups (P<0.05). Both low-intensity pulsed ultrasound and Clematis chinensis Osbeck can promote the proliferation of cartilage cells and expression of type II col agen and t-β1 of rabbit knee articular chondrocytes cultured in vitro. The combined method could produce synergistic effects.
RÉSUMÉ
BACKGROUND:The narrowing of intervertebral space induced by the intervertebral disc degeneration is mainly characterized by the expression of proteoglycan in nucleus pulposus cells and the reduction of col agen type II. OBJECTIVE:To quantitatively observe col agen type II protein in adult normal and degenerative intervertebral disc nucleus pulposus cells by immunofluorescence staining and safranin O staining. METHODS:The nucleus pulposus specimens were col ected from adult scoliosis patients and patients with intervertebral disc protrusion, who were al volunteers. After culture, 26 cells in each patient were measured. There were 78 cells in both normal group and degeneration group. The normal and degenerative intervertebral disc nucleus pulposus cells were subjected to safranin“O”staining, and gray values were determined;intracellular col agen type II was detected by immunofluorescence staining. RESULTS AND CONCLUSION:Immunofluorescence staining revealed that, degenerative intervertebral disc nucleus pulposus cells were only mildly stained, with the fuzzy staining, the shape was round, spindle, fusiform and irregular. There were a very smal amount of fluorescent particles within cells. The expression of col agen type II was decreased significantly compared with normal cells (P0.05). The degenerative intervertebral disc nucleus pulposus cells have a smal quantity and partial y become apoptotic, the content of col egen type II protein is decreased significantly compared with normal nucleus pulposus cells.
RÉSUMÉ
BACKGROUND:The auditory ossicle chain reconstruction is stil an important method to treat conductive deafness. Although a great variety of materials have been applied, the blood supply of otosteon after the implantation is ignored. Moreover, there is no real bone formed. OBJECTIVE:To observe the angiogenesis of vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold which is implanted into the otocyst of guinea pig. METHODS:Total y 60 guinea pigs were randomly divided into experimental group (vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold), col agen I control group (col agen I modifiedβ-tricalcium phosphate porous scaffold) and blank control group (β-tricalcium phosphate porous scaffold). The guinea pigs were executed under anesthesia at weeks 1, 2, 3, 4 respectively. The surface of scaffolds was observed by scanning electron microscopy. The angiogenesis of scaffolds were observed by hematoxylin-eosin staining and CD34 immunohistochemistry staining, and then the microvascular density was counted. The osteogenesis of the scaffolds was observed by toluidine blue staining. RESULTS AND CONCLUSION:Endothelial cel proliferation and lumen formation could be observed after 1 week in the experimental group, and the angiogenesis reach the peak after 3 weeks with traffic branches formedbetween micropores. In the other two groups, the lumen formed at 2 weeks but no traffic branches were visible. The sprouting of new blood vessels in the pores were observed more in the experimental group than the other two groups (P<0.05). The adherence and proliferation of cel s could be examined in the surface and pores of the scaffold by scanning electron microscope. After 4 weeks, the osteogenesis could be observed by toluidine blue staining, especial y in the experimental group. These findings suggest that the vascular endothelial growth factor and col agen I modifiedβ-tricalcium phosphate porous scaffold can realize an effective vascularization in the environment of guinea pigs’ middle ear. What’s more, the scaffold also can promote bone formation.
RÉSUMÉ
BACKGROUND:Rheumatoid arthritis is a common chronic systemic autoimmune disease which is characterized by synovial lesions and bone erosion. The clinical treatment is stil a difficulty. OBJECTIVE:To explore the effect of exogenous hydrogen sulfide on the articular lesions in rheumatoid arthritis rats. METHODS:Sprague-Dawley rats were divided into four groups:control group, model group, high concentrations of hydrogen sulfide intervention group, low concentrations of hydrogen sulfide intervention group. At 2 and 4 weeks after intervention, the arthritis index, levels of serum inflammatory cytokines (tumor necrotic factor-αand interleukin-1β), pathological change of synovial tissue, average absorbance of knee joint specimens using col agen-II immunohistochemical staining were measured. RESULTS AND CONCLUSION:The arthritis index, levels of serum inflammatory cytokines and inflammatory infiltration of synovial staining in the model group and two intervention groups were higher than that in control group, the high concentrations of hydrogen sulfide intervention group was significantly higher than the model group (P<0.05) while the low concentrations of hydrogen sulfide intervention group was lower than the model group (P<0.05). The average absorbance of knee cartilage specimens using col agen-II immunohistochemical staining was lower in the model group and two hydrogen sulfide intervention groups compared with the control group, the high concentrations of hydrogen sulfide intervention group was significantly lower than the model group (P<0.05) while low concentrations of hydrogen sulfide intervention group was higher than the model group (P<0.05). Hydrogen sulfide has a regulatory effect on rheumatoid arthritis, high concentrations of hydrogen sulfide aggravate arthritis and cartilage degradation, low concentrations of hydrogen sulfide reduce arthritis and protect cartilage.
RÉSUMÉ
BACKGROUND:Col agen suture is made of col agen from animals, and has been widely used because it is absorbable, non-rejection and easy to produce, and convenient in use. OBJECTIVE:To evaluate the effects of col agen suture and silk suture in wound healing after oral implant surgery. METHODS:100 patients undergoing oral implantation were randomly assigned into col agen suture group and silk suture group. A 2-0 circular needle with absorbable col agen sutures and a 4-0 circular needle with non-absorbable silk sutures were employed for tension-free suture in the two groups. After 3, 5, 7 days of oral implantation, suture threads and wound healing were observed. The suture was removed at 14 days, and patients were reviewed at 14 days. RESULTS AND CONCLUSION:The wound healing was better in the col agen suture group than the silk suture group at grade I (P<0.05). At 7 days postoperatively, the suture thread was mostly absorbed in the col agen group but not in the silk suture group. In addition, material alba was invisible in the col agen suture group but clear in the silk suture group. These results indicate that the col agen suture is more proper for tension-free suture than the silk suture, which is better matched to the healing time and keeps a better oral environment.
RÉSUMÉ
BACKGROUND:Chinese herb Cape Jasmine Fruit can activate the chondrocytes and geniposide is an important component in this herb. OBJECTIVE:To investigate the effect of geniposide on col agen II synthesis in rat chondrocytes cultured in vitro. METHODS:Rat chondrocytes were separated and cultured in vitro. The chondrocytes were then interfered with 25, 50 and 100 mmol/L geniposide. Normal control group was also set. Col agen II mRNA and protein expression was detected with semi-quantitative RT-PCR and western blot analysis, respectively. RESULTS AND CONCLUSION:RT-PCR and western blot analysis results showed that, geniposide at 25, 50 and 100 mmol/L increased the col agen II mRNA and protein expression (P<0.01). Geniposide can promote the synthesis of col agen II in rat chondrocytes cultured in vitro.
RÉSUMÉ
BACKGROUND:Col agen/bioactive glass composite materials possess excellent osteogenic potential and biocompatibility, but its application in bone tissue engineering is limited by mechanical property and degradation. OBJECTIVE:To construct col agen/bioactive glass/chitosan composite scaffolds with good mechanical property, anti-degradation ability and bone repair property. METHODS:Bioactive glass/col agen composite scaffolds with chitosan as dispersant were prepared by lyophylization. Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction, and dynamic biomechanical testing were used to characterize the structure and properties of the composite scaffolds. RESULTS AND CONCLUSION:Results show that charge-attractions in pre-prepared bioactive glass/chitosan solution increased the homogeneity of bioactive glass dispersed in col agen gel and the compressive modulus and strength increased significantly due to the homogeneity and intermolecular interactions between chitosan and col agen. The enzymatic degradation rate and mineralization activity in the simulated body fluid were also lower because of a high degree of embedment of bioactive glass in col agen/chitosan matrix, and entanglement of col agen in chitosan at molecular level, which decreased the exposure of bioactive glass to the simulated body fluid, and col agen to enzyme solution.
RÉSUMÉ
BACKGROUND:Many experiments have demonstrated that tissue engineering scaffolds prepared by polymer materials alone or biomaterials cannot meet the requirement of tissue engineering research. OBJECTIVE:To evaluate biological characteristics and cel affinity of poly(hydroxybutyrate-co-hydroxyoctanoate)/col agen composite scaffold. METHODS:Tissue engineering scaffolds were prepared by combination of poly(hydroxybutyrate-co-hydroxyoctanoate) and col agen at different proportions (2%, 4%, 6%, 8%and 10%) using solvent casting/particulate leaching method. Inner structure and apertures were observed by scanning electron microscope, and the porosity was determined by liquid displacement method. Rabbit chondrocytes were co-cultured with poly(hydroxybutyrate-co-hydroxyoctanoate)/col agen composite scaffold and poly(hydroxybutyrate-co-hydroxyoctanoate) scaffold. Growth curve of cel s was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cel adhesion on the scaffolds was observed by scanning electron microscope. RESULTS AND CONCLUSION:The pore size and porosity of the composite scaffold were about 200μm and (85±2)%, respectively. The cel affinity dynamical y increased with the increasing of proportion of col agen. Compared with the poly(hydroxybutyrate-co-hydroxyoctanoate) scaffold, the poly(hydroxybutyrate-co-hydroxyoctanoate)/col agen composite scaffolds are better to improve cel adhesion and proliferation, with favorable cel ular affinity.
RÉSUMÉ
BACKGROUND:Col agen and silk fibroin materials for construction of spinal cord scaffolds have been proven to repair or partial y repair damaged spinal cord nerve function. OBJECTIVE:To introduce partial characteristics of the col agen and silk fibroin and to review the recent progress and application as scaffolds in spinal cord tissue engineering. METHODS:A computer-based search of CNKI and PubMed databases (2003-01/2012-10) was performed for articles addressing the application of col agen and silk fibroin scaffolds in spinal cord injury with the keywords of“col agen, silk fibroin, scaffold, spinal cord injury”in Chinese and English, respectively. RESULTS AND CONCLUSION:Col agen has low antigenicity, good biocompatibility and biodegradability. Col agen and its degradation products can cause no inflammatory reactions in the body, but have the disadvantages of rapid degradation and poor mechanical properties. Silk fibroin has good biocompatibility and excellent mechanical properties, but its degradation is slow. The col agen and silk fibroin are compounded using an electrostatic spinning technology to improve the physical properties of the material on the basis of maintaining good biocompatibility. At present, fibroin or col agen materials in terms of nervous system repair have been studied, laying some foundation for spinal cord tissue engineering. Considering the similar characteristics and mechanics performance to the spinal cord tissue, col agen/silk fibroin composite materials are expected to become the ideal scaffold materials for spinal cord tissue engineering.
RÉSUMÉ
BACKGROUND:Platelet-rich plasma has benefit in diabetic wound healing;however, the effect of al ogeneic platelet-rich plasma is stil unclear. OBJECTIVE:To observe the effect of al ogeneic platelet-rich plasma on col agen synthesis during diabetic wound healing. METHODS:Streptozocin-induced diabetic rats were randomly divided into al ogeneic platelet-rich plasma group and saline control group. Each group had 15 rats. A 1 cm2 ful-thickness skin defect on the rat dorsum was excised. Platelet-rich plasma or saline was applied. Platelet-rich plasma was prepared from the whole blood of al ogeneic healthy rats. Animals of each group were sacrificed on 3, 7, 14 days post operation. The differences of the wound closure rate, morphological character, hydroxyproline content and the relative mRNA expression of the col agen were observed. RESULTS AND CONCLUSION:The wound closure rates were lower in control group on day 3, 7, 14 post operation (P<0.05). Masson staining showed a decreased, disorder, loose col agen fibers distribution in diabetic control wound tissue. The results of the hydroxyproline test showed hydroxyproline content was significantly higher in platelet-rich plasma group at each time point (P<0.01). The relative mRNA expression of type I and III col agen presented a higher expression in platelet-rich plasma treated wound tissue at each time point (P<0.05). And the ratio between type I and III col agen was higher in platelet-rich plasma group at each time point (P<0.05). In summary, al ogeneic platelet-rich plasma can promote diabetic wounds healing, which may attribute to an enhanced col agen synthesis.
RÉSUMÉ
10.3969/j.issn.2095-4344.2013.26.015
RÉSUMÉ
BACKGROUND:Shengji Yuhong col agen showed good curative effect of promoting angiogenesis and tissue healing compared with Shengji Yuhong Gao and col agen alone or gelatin alone. OBJECTIVE:To explore the curative effect and mechanism of subcutaneous implantation of Shengji Yuhong col agen in rabbits in promoting angiogenesis and repair. METHODS:Shengji Yuhong col agen as the experimental group and collagen as the control group was implanted inside the rabbit subcutaneous pockets of the back of New Zealand rabbits. The implanted samples and surrounding tissues were obtained at 3, 7, 14, 28 and 56 days fol owing surgery. Pathological sections were made and the repair of surrounding tissue was observed. Hemoglobin levels in col agen were measured. Immunofluorescence and CD34 dyeing marking method were utilized to observe capil ary angiogenesis. Western blot assay was employed to examine vascular endothelial growth factor and angiogenin-1 expression. Immunohistochemistry was used to observe the secretion of typeⅠ and Ⅲ col agen on the surrounding tissues. RESULTS AND CONCLUSION:The experimental group showed increased subcutaneous vascularization. There were reduced inflammatory exudation, granulation tissue hyperplasia, and mature fiber connective tissue at 28 days. Angiogenesis and hemoglobin contents were greater in the experimental group than in the control group (Pidentical between the experimental and control groups. However, the secretion of type Ⅲ col agen was higher in the experimental group than in the control group at 28 and 56 days (Pcol agen was lower in the experimental group than in the control group at 28 and 56 days (Pmechanisms of adjusting the protein expression of vascular endothelial growth factor and angiogenin-1. At the same time, it has the function of regulating col agen formation with better ratio of typeⅠ and type Ⅲ col agen to acquire higher quality of wound healing with reduced scar formation.
RÉSUMÉ
BACKGROUND:Membrane guided bone regeneration technology has become an important method in repairing bone defects. With the deepening of the research, related concept and the mechanism of membrane guided bone regeneration have been gradual y confirmed, but there are stil some unresolved issues. OBJECTIVE: To review the classification of membrane tubes, performance, disadvantages and advantages in membrane guided bone regeneration, as wel as some unresolved issues in application and research. METHODS:The first author searched PubMed and CNKI databases to retrieve articles about the discovery of membrane guided bone regeneration and the concepts, classification of membrane tubes, performance, disadvantages and advantages during bone defect treatment, which were published from 1963 to 2013. The key words were“guided bone regeneration, guided tissue regeneration, bone defect treatment”in English and Chinese, respectively. RESULTS AND CONCLUSION:Membrane guided bone regeneration technique is a most promising treatment for bone defects, but for the treatment of long tubular bone defects, it is stil in the experimental stage. Currently, there is no membrane tube for long-segment bone defects. According to the material sources, the membrane tubes can be divided into:non-biological material, such as polytetrafluoroethylene, polylactic acid, silica gel, titanium film;biological materials, such as col agen membrane, chitin membrane, polyhydroxybutyrate. The membrane tubes can also be classified into nondegradable materials and biodegradable materials. Biodegradable materials have good histocompatibility and no cytotoxicity, which can degrade in a certain period after implantation;part of the membrane can also al ow free exchange of tissue fluid and nutritional substances. But there are stil some shortcomings that the degradation time is difficult to control and the volume is difficultly maintained under the membrane tube. New bone formation in non-biodegradable materials is complete. In the process of osteogenesis, the membrane tube cannot be absorbed and has to be removed secondarily, though it has good histocompatibility and better therapeutic outcomes. In the future, we should further improve membrane performance, so that the membrane tube can play a dual role, fixation and guided bone regeneration;a series of animal studies should be conducted to study the effect of stress on the membrane tube and osseointegration within the membrane tube, to master the law of osseointegration of membrane tubes, thereby providing evidence for repair of long tubular bone defects.