OBJECTIVE: To fabricate artificial human skin with the tissue engineering methods. METHODS: The artificial epidermis and dermis were fabricated based on the successful achievements of culturing human keratinocytes(Kc) and fibroblasts (Fb) as well as fabrication of collagen lattice. It included: 1. Culture of epidermal keratinocytes and dermal fibroblasts: Kc isolated from adult foreskin by digestion of trypsin-dispase. Followed by comparison from aspects of proliferation, differentiation of the Kc, overgrowth of Fb and cost-benefits. 2. Fabrication of extracellular matrix sponge: collagen was extracted from skin by limited pepsin digestion, purified with primary and step salt fraction, and identified by SDS-PAGE. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde, in which the collagen appeared white, fibrous, connected and formed pores with average dimension of 180 to 260 microns. 3. Fabrication artificial human skin: The artificial skin was fabricated by plating subcultured Kc and Fb separately into the lattice with certain cell density, cultured for one week or so under culture medium, then changed to air-liquid interface, and cultured for intervals. RESULTS: The artificial skin was composed of dermis and epidermis under light microscope. Epidermis of the skin consisted of Kc at various proliferation and differentiation stages, which proliferated and differentiated into basal cell layer, prickle cell layer, granular layer, and cornified layer. Conifilament not only increased in number, but also gathered into bundles. Keratohyalin granules at different development stages increased and became typical. The kinetic process of biochemistry of the skin was coincide with the changes on morphology. CONCLUSION: Tissue engineered skin equivalent has potential prospects in application of repairing skin defect with advantages of safe, effective and practical alternatives.
OBJECTIVE To investigate the ectopic osteogenesis of bone marrow stromal cells (MSC) induced by bone morphogenetic protein(BMP) in vitro and in vivo, providing the experimental evidence for making an artificial bone with its own capacity of bone formation. METHODS MSC were separated and cultured from bone marrow of Wistar rats, MSC were co-cultured with BMP in vitro (cultured in plate and diffuse chamber). Artificial coral hydroxyapatites (CHA) with MSC and BMP were implanted into dorsal muscles of Wistar rats, their bone formation were observed by morphological examination, histochemistry and immunohistochemistry. RESULTS Only cartilaginous matrix were produced by MSC in vitro (cultured in plate and diffuse chamber), and both cartilaginous and bone matrix production within the combined grafts were seen. The bone formation of experimental groups (CHA + BMP + MSC) was ber than that of control A(CHA + MSC) and control B(CHA). CONCLUSION It may be possible to produce an artificial bone with its own capacity of bone formation by combined graft (CHA + BMP + MSC). There may be multiple factors as well as BMP inducing bone formation both in the whole body and the location of the implantation. Further research on these factors will have the significance for making the ideal artificial bone.
OBJECTIVE: To study the effect of platelet-rich plasma in the repair of bone defect. METHODS: Segmental bone defects of 1 cm were created in the mid-upper part of bilateral radius of 24 New Zealand white rabbits. One side was randomly chosen as the experimental side, which was filled with artificial bone with platelet-rich plasma (PRP). The other side filled with artificial bone without PRP as the control. After 2, 4, 8 and 12 weeks of implantation, the gross, radiological, histological observations, and computer graphic analysis were performed to investigate the bone healing of the defect in both sides. RESULTS: Two weeks after operation, new bone and fibrous tissue formation in both the experimental and the control sides were observed only in the areas adjacent to the cut ends of the host bone, but the amount of new tissue in the experimental side was much more than that in the control side. In the 4th and 8th weeks, the surface of the artificial bone was covered with a large amount of new bones, the artificial bone was bridged tightly with the host bone by callus in the experimental side, while new bone was limited mainly in the cut ends and was less mature in the control side. In the 12th weeks, bone defects were entirely healed in the experimental side, which were covered completely with cortical bone, while new bone formation was only observed in the ends of artificial bone and there were not continuous bone callus on the surface in the control side. CONCLUSION: Artificial bone with PRP is effective in the repair of segmental bone defects, and PRP could improve the healing of bone defect.
Objective To understand the value of pre-coating in artificial vessel endothelialization. Methods Literature concerning precoating in artificial vessel endothelialization was extensively reviewed. Results Pre-coating included chemical coatings(collagen, fibronectin, laminin, poly-l-lysin, gelatin andextracellular matrix), pre-clotting(plasma, blood, serum and fibrin glue), chemical bonding (heparin, RGD and lectins) and surface modification. Most of them could enhance the adhesion of the endothelial cells. Conclusion Pre-coating couldimprove endothelialization, but further research is needed to search for the appropriate concentration and incubation time.
Objective To study the cl inical appl ication of Mobi-C prosthesis in treatment of anterior cervical discectomy and artificial disc replacement (ADR). Methods Between January 2009 and June 2009, 20 cases of degenerative cervical disease were treated with anterior discectomy and ADR by Mobi-C prosthesis, including 13 cases of cervical disc herniation and 7 cases of cervical spondylotic radiculopathy, and 25 Mobi-C prosthesis were implanted. There were 8 males and 12 females, aged 29-54 years (mean, 45.2 years). The disease duration was from 4 days to 5 years (mean, 1.2 years). Affected segments of process included C3, 4 in 1 case, C4, 5 in 2 cases, C5, 6 in 7 cases, C6, 7 in 5 cases, C4, 5 and C5, 6 in 2 cases, and C5, 6 and C6, 7 in 3 cases. Radiographs were taken regularly, and cervical range of motion (ROM) on segments of disc replacements were measured. The functions of cervical spinal cord were evaluated by “40 score” system (COA) preoperatively, immediately postoperatively, and at follow-up. The qual ity of l ife was evaluated by neck disabil ity index (NDI) and visual analogue scale (VAS) score. Results All incisions healed by first intention. No perioperative compl ication was found. All cases were followed up 16.5 months on average (range, 14-18 months). There was no significant difference in cervical ROM of operatied segment between preoperation and follow-up duration (t=0.808，P=0.440). No heterotopic ossification was found at follow-up. COA score at last follow-up (38.20 ± 1.14) was significantly higher than preoperative one (32.10 ± 2.96) , (t=9.278，P=0.000) , and the improvement rate at last follow-up was 77.2% ± 5.4%. VAS score at last follow-up (3.20 ± 1.23) had significant difference when compared with preoperative one (5.10 ± 1.29), (t=10.585，P=0.000). NDI score at last follow-up (29.40 ± 4.55) had significant difference when compared with preoperative one (39.20 ± 3.80), (t=16.039, P=0.000). Conclusion A satisfactory short-term curative effect can be obtained by using Mobi-C prosthesis in treatment of anterior cervical discectomy and ADR.
In order to restore the function of shoulder joint in patient with tumor of upper end of humerus, artificial humeral head replacement was performed. The materials included resinene, nylon-6 and large molecular polyethylene from 1978 to 1993, 14 patients were treated. The tumors involved in this group were giant cell tumor, synviosarcoma, bone cyst, osteochondroma, osteoblastoma, osteofibrosarcoma, osteosarcoma, chondrosarcoma, parosteosarcoma and malignant giant cell tumor. After resection of the tumor, the artificial prosthesis was implanted with bone cement. After 1 to 16 years follow-up, functions of the shoulder joint were reserved in 86% of the patients.
Abstract To investigate the ectopic new bone formation following implantation of bovine hydroxyapatite Bio-oss together with free periosteum, 12 chabb: ch rabbits were selected. In 10 rabbits, Bio-oss block together with free periosteum was implanted in the gastrocnemius muscle of one leg randomly, and Bio-oss block alone was implanted in the same muscle of the other leg. In the other 2 rabbits, the periosteum was implanted into the gastrocnemius musle of both legs. Histologic examination and quantitative analysis of newbone formation were performed at 3 and 6 weeks postoperatively. The results showed that in the legs implanted bovine hydroxyapatite Bio-oss together with freeperiosteum, new bone formation began at 5th day after implantation. The area ofnew bone composed of 19.0% of the specimens at 3 weeks postoperatively. No boneformation through out the experimental period in Bio-oss block alone implantedlegs and also periosteum implanted legs. We concluded that bovine hydroxyapatite Bio-oss has a good capacity of osteoconduction. New bone can be formed after the implantation of hydroxyapatite combined with free periosteum.
Objective To explore the advance in physical materials,chemical matrix, and biological seed cells for fabricating artificial nerve. Methods Recent literature relevant to artificial nerve, especially the achievement in physical material, chemical matrix and biological seed cells for fabricating artificial nerve, were extensively reviewed. Results Polymers of polylactic acid or polyglycolic acid and their polymer, polymer of hyaluronic acid and glut-aldehyde, polymer of polyacrylonitrile and polyvinylchloride were artificial nerve materials with the properties of good biocompatibility and biodegradation. A conduit with multichannel and high percentage of pores was beneficial to the regeneration of nerve. The activated Schwann cells were excellent seeds of artificial nerve. A suitable chemical matrix, such as laminin and alginate, could promote the regeneration of nerve. Conclusion The successful fabrication of artificial nerve lies in the advance in the mechanism of nerve regeneration and physical material, chemical matrix and biological seed cells.
Objective To explore the influence of discectomy and artificial disc replacement on the upper lumbar facet joint and to provide the evidence for use of artificial disc replacement. Methods Under the loads of 200-2 000 N axis pressure and 1-10 Nm back-extending/side-bending pressure on the 7 fresh adult corpses, the pressure of L3,4facet joint was measured in the case of L4,5disc integrity, discectomy and artificial disc replacement and the statistical analysis was done.ResultsUnder the same load (axis, back-extending/side bending), there were significant differences (Plt;0.01) in the pressure of upper lumbar facet jointboth between disc integrity and discectomy and between discectomy and artificial disc replacement, and there was no difference(Pgt;0.05) between disc integrity and artificial disc replacement. Conclusion The stress ofupper lumbar facet joint reduced after discectomy, it implies that simply discectomy may change biomechanics of lumbar and lead to secondary lumbar structure degeneration. The stress of upper lumbar facet joint is close to the normal value after artificial disc replancement, it implies that artificial disc replacement may protect lumbar structure. It provides some biomechanics foundation and evidence for artificial disc replacement.
【Abstract】Objective To evaluate effect of artificial liver support system (ALSS) in liver failure and liver transplantation.Methods Forty-four patients with liver failure (including 12 undergoing liver transplantation) were treated with MARS or plasma exchange. The changes of toxic substances and cytokines in blood were detected before and after treatment. Results ALSS therapy achieved a remarkable improvement in clinical symptoms and physical signs. After ALSS treatment, there was a significant decrease in total bilirubin, total bile acid, alanine aminotransferase, creatinine, urea nitrogen, blood ammonia and endotoxin levels(P＜0.05); the levels of serum NO, TNF-α, IL-4 and IL-6 were significantly decreased(P＜0.05); there was no statistical change in erythrocytes, leukocytes and platelets. The survival rate of 30 liver failure patients caused by severe hepatitis B was 60.0%(18/30). Six patients with acute liver failure were successfully performed liver transplantation. Two patients in 6 with acute liver failure after liver transplantation survived. One patient in 2 with acute liver failure after pancreatoduodenectomy survived. Conclusion ALSS plays a positive role in treatment of liver failure by removing blood toxins, NO and cytokines. ALSS also plays a substitute role for liver failure patients who are waiting for liver transplantation.