OBJECTIVE To study the clinical effect of chitosan on prevention of elbow adhesion after elbow arthrolysis. METHODS Twenty six patients with elbow ankylosis were performed elbow arthrolysis, which divided into two groups, in chitosan group, 12 patients were injected 2% chitosan into the elbow joint cavity, and no chitosan used in the other 14 patients as control group. The average range of extension and flexion of elbow joint was detected to evaluate the clinical results. RESULTS All patients were followed up 8 to 51 months, averaged 24 months. In the chitosan group, the average range of extension and flexion of elbow joint was restored to 92.9 degrees +/- 20.9 degrees, with an average increase of 55.0 degrees +/- 15.9 degrees compared with preoperation. In the control group, the average range of extension and flexion of elbow joint was restored to 75.4 degrees +/- 17.5 degrees, with an average increase of 38.2 degrees +/- 11.9 degrees. The outcome showed significant difference between the chitosan group and the control group (P lt; 0.01). CONCLUSION Chitosan can prevent or reduce elbow adhesion after elbow arthrolysis.
Objective To compare the effect and coverage of bacteriostasis of chitosan and sodium hyaluronate. Methods Each of the five bacteria, Proteus mirabilis, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus, was cultivated for 33 tubes of broth culture. Leaving three tubes each group as control group, ploidy diluted concentration of high relative molecular weight chitosan, low relative molecular weight chitosan and sodium hyaluronate were added respectively in the broth culture. All the tubes were cultivated for 18 hours at 37 ℃ with homeothermia. Then the growth of bacteria was observed. ResultsThe minimal inhibitory concentrations (MIC) of high relative molecular weight chitosan were : Proteus mirabilis 0.031%, Escherichia coli 0.063%, Candida albicans 0.063%, Pseudomonas aerugionosa 0.063%, Staphylococcus aureus 0.063%; and the MIC of low relative molecular weight chitosan were: Proteus mirabilis 0.125%, Escherichia coli 0.025%, Candida albicans 0.25%, Pseudomonas aeruginosa 0.25%, Staphylococcus aureus 0.125%; bacteria grew well in each tube of sodium hyaluronate group and control group. Conclusion The above results show that sodium hyaluronate has no bacteriostasis, while chitosan has bacteriostasison broad spectrum and high relative molecular weight chitosan has ber effect.
In order to observe the curative effect and general reaction of locally used adriamycin (ADM)-loaded chitosan drug delivery system on giant cell tumor of bone after curettage. The cavities of 4 cases of giant cell tumor after curettage were filled with ADM-loaded chitosan drug delivery system with 4 times the dosage usually used for intravenous application. After operation, the concentration of ADM in plasma on the 1st, 2nd and 5th day, and the functions of liver and kidney on the 1st week, 1st month and 6th month were all investigated. The results were that the concentration of ADM in plasma was (143.05 +/- 27.55) ng/ml, (52.17 +/- 11.28) ng/ml and (4.25 +/- 3.07) ng/ml respectively, and the functions of liver and kidney were all normal in 6 months. After a follow-up of 7-19 months, no local or general reactions were observed and X-ray showed no recurrence. Therefore, it was concluded that the locally used ADM-loaded chitosan delivery system was safe and effective in treatment of giant cell tumor of bone after curettage.
OBJECTIVE: To prepare chitosan-gelatin/hydroxyapatite (CS-Gel/HA) composite scaffolds, and to investigate the influence of components and preparing conditions to their micromorphology. METHODS: The CS-Gel/HA composite scaffolds were prepared by phase-separation method. Micromorphology and porosity were detected by using scanning electron microscope and liquid displacement method respectively. RESULTS: Porous CS-Gel/HA composite scaffolds could be prepared by phase-separation method, and their density and porosity could be controlled by adjusting components and quenching temperature. CONCLUSION: The study suggests the feasibility of using CS-Gel/HA composite scaffolds for the transplantation of autogenous osteoblasts to regenerate bone tissue.
OBJECTIVE: To repair esophageal defects with an artificial prosthesis composed of biodegradable materials and nonbiodegradable materials, which is gradually replaced by host tissue. METHODS: The artificial esophagus was a two-layer tube consisting of a chitosan-collagen sponge and an inner polyurethane stent with a diameter of 20 mm and a length of 50 mm. We used the artificial esophagus to replace 5 cm esophageal defects in group I (five dogs) and in group II (ten dogs), and nutritional support was given after operation. The inner polyurethane stent was removed after 2 weeks in group I and after 4 weeks in group II endoscopically and epithelization of the regenerated esophagus was observed by histologic examination and transmission electron microscope. RESULTS: In group I, the polyurethane stent was removed after 2 weeks, and partial regeneration of esophageal epithelial was observed; and constriction of the regenerated esophagus progressed and the dogs became unable to swallow after 4 weeks. In group II, the polyurethane stent was removed after 4 weeks, highly regenerated esophageal tissue successfully replaced the defect and complete epithelization of the regenerated esophagus was observed. After 12 weeks, complete regeneration of esophageal mucosa structures, including mucosal smooth muscle and mucosal glands and partial regeneration of esophageal muscle tissue were observed. CONCLUSION: Esophageal high-order structures can be regenerated and provided a temporary stent and support by polyurethane stent and an adequate three-dimensional structure for 4 weeks by collagen-chitosan sponge.
Objective To investigate the effects of chitosan/polyvinyl alcohol (PVA) nerve conduits for repairing radial nerve defect in Macaques. Methods Twelve adult Macaques weighing 3.26-5.35 kg were made the models of radial nerve defect (2 cm in length) and were randomly divided into 3 groups according to nerve grafting, with 4 Macaques in each group. Chitosan/PVA nerve conduit, non-graft, and autografts were implanted in the defects in groups A, B, and C, respectively. And the right radial nerves were used as normal control. At 8 months postoperatively, the general observation,electrophysiological methods, and histological examination were performed. Results At 8 months postoperatively, theregenerated nerve bridged the radial nerve defect in group A, but no obvious adhesion was observed between the tube and the peripheral tissue. The regenerated nerve had not bridged the sciatic nerve defect in group B. The adhesions between the implanted nerve and the peri pheral tissue were significant in group C. Compound muscle action potentials (CMAP) were detected in group A and group C, and no CMAP in group B. Peak ampl itude showed a significantly higher value in normal control than in groups A and C (P lt; 0.05), but there was no significant difference between groups A and C (P gt; 0.05). Nerve conduction velocity and latency were better in normal control than in groups A and C, and in group C than in group A, all showing significant differences (Plt; 0.05). The density of myl inated fibers in groups A and C was significantly lower than that in normal control (P lt; 0.05), but there was no significant difference between groups A and C (P gt; 0.05). The diameter and the myel in sheath thickness of the myl inated fibers in normal control were significantly higher than those in groups A and C, and in group C than in group A, all showing significant differences (P lt; 0.05). Conclusion The chitosan/PVA nerve conduits can promote the peripheral nerve regeneration, and may promise alternative to nerve autograft for repairing peripheral nerve defects.
Objective To fabricate a nanohydroxyapatite-chitosan(nano-HA-CS) scaffold with high porosity by a simple and effective technique and to evaluate the physical and chemical properties and the cytocompatibility of the composite scaffold. Methods The threedimensional nano-HA-CS scaffolds with high porosity were prepared by the in situ hybridization-freeze-drying method. The microscopic morphology and components of the composite scaffolds were analyzed by the scanning electron microscopy (SEM), the transmission electron microscopy（TEM）, the X-ray diffraction（XRD）examination, and the Fourier transformed infrared spectroscopy（FTIR）. The calvarial osteoblasts were isolated from the neonatal Wistar rats. The serial subcultured cells (3rd passage) were respectively seeded onto the nanoHACS scaffold and the CS scaffold, and then were cocultured for 2, 4, 6 and 8 hours. At each time point,four specimens from each matrix were taken to determine the celladhesion rate. The cell morphology was observed by the histological staining and SEM. Results The macroporous nanoHACS scaffolds had a feature of high porosity with a pore diameter from 100 to 500 μm (mostly 400500 μm). The scaffolds had a high interval porosity; however, the interval porosity was obviously decreased and the scaffold density was increased with an increase in the contents of CS and HA. The SEM and TEM results showed that the nanosized HA was synthesized and was distributed on the pore walls homogeneously and continuously. The XRD and FTIR results showed that the HA crystals were carbonatesubstituded and not wellcrystallized. The cytocompatibility test showed that the seeded osteoblasts could adhere the scaffolds, proliferating and producing the extracellular matrix on the scaffolds. The adherence rate for the nanoHACS scaffolds was obviously higher than that for the pure CS scaffolds. Conclusion The nano-HA-CS scaffolds fabricated by the in situ hybridization-freeze-drying method have a good physical and chemical properties and a good cytocompatibility; therefore, this kind of scaffolds may be successfully used in the bone tissue engineering.
Objective To investigate the clinical effect of chitosan in prevention of knee dysfunction due to adhesion after operation for patellar fracture. Methods From March to October 1999, 40 cases of patellar fracturewere treated by internal fixation, with intraarticular injection of 2% chitosan in only 24 cases after fixation and with no chitosan injection in 16 cases(control group). The function of the knee joint, including extension and flexion, was evaluated 1month and 1 year after operation respectively. Results One month after operation, the knees with chitosan injection could actively move in the average range of 104°±23°, and the knees in the control group could move in the average range of72°±16°, which showed significant difference between two groups(P＜0.01); 1 year after operation, the range of movement of the knees with injection was 165°±38° on average, and that of the knees in the control group was 110°± 31°, which also indicated significant difference between two groups (P＜0.05). Conclusion Medical chitosan could effectively prevent or reduce the post-operative adhesion of knee joint after patellar operation.
ObjectiveTo study the long-term prevention effect of self-developed chitosan electrospun membrane on cerebrospinal fluid leakage. MethodsTwenty-five healthy adult New Zealand rabbits were selected to prepare the bilateral dural defect (0.8 cm×0.8 cm in size) via midline incision of head.Defect of the right was repaired with chitosan electrospun membrane as the experimental group; defect of the left was not repaired as the control group.At 2-16 weeks after operation,one rabbit was sacrificed for the general observation of inflammatory response surrounding bone window and absorption of chitosan electrospun membrane; at 3 and 6 weeks after operation,5 rabbits were sacrificed for sampling to observe histological change and collagen expression by HE and Masson staining,and to measure the expressions of epidermal growth factor receptor (EGFR) and basic fibroblast growth factor (bFGF) by immunohistochemical staining. ResultsNo inflammatory reaction of swelling,exudation,and sppuration appeared in the skin and subcutaneous tissue after operation in 2 groups.There was no adhesion around the chitosan electrospun membrane,and new fiber membrane formed under the chitosan electrospun membrane in the experimental group; no cerebrospinal fluid leakage happened; the chitosan electrospun membrane was gradually degraded with time,and was completely absorbed at 16 weeks.There was uneven scar around the dural detect in control group.Histological observation showed less inflammatory cell infiltration in the experimental group,showing significant difference in the number of inflammatory cells compared with control group at 3,6 weeks (P<0.05); capillary,granulation tissue and collagen fiber massively proliferated; collagen fiber arranged in line,and there was a clear borderline between chitosan electrospun membrane and adjacent collagen fiber.The immunohistochemical staining showed that there were high expressions of bFGF and EGFR in the experimental group,and low expressions of bFGF and EGFR in the control group. ConclusionChitosan electrospun membrane for dural defect of rabbit can effectively reconstruct the dura,and it has exact long-term prevention effect on cerebrospinal fluid leakage.
Objective To study the allograft effect of two kinds of tissue engineered oral mucosa lamina proprias on skin fullthickness wounds. Methods The cultured Wistar rat oral mucosa fibroblasts (OMF) were incorporated into collag en or chitosancollagen to construct the tissue engineered oral mucosa laminaproprias, and then the OMFs were labeled with BrdU. The fullthickness round skin defects were made with a round knife (diameter, 0.8 cm) on the backs of 36 Wistar rats (2125 weeks old), which were divided into 2 experimental groups: the fibroblastpopulated collagen lattices (FPCL) group (grafted by FPCLs) and the fibroblastpopulated chitosan collagen lattices (FPCCL) group (grafted by FPCCLs), and the control group (only covered with gauges). All the wounds were observed by the naked eyes or the light microscope, and were measured 4, 7, 14, and 21 days postoperatively. Results There were no infection during the wound healing period. At 7 days after the grafting, the wounds in the 3 groups were covered by scab and/or gauze; at 14 days, the gauze and scab on the wounds in the three groups were all replaced by the new epidermis naturally except one scab each in the FPCCL group and the control groups,which was replaced at 17 days.All the centers of the new epidermis were measurable as the pink red points. At 21 days, all the new skins were smooth without hairs, and their color was similar to the normal one. At 4, 7, and 14 days,there was an indication that the wound diameters became significantly smaller in the three groups; but after the 14th day, there was no significant indication of this kind. At 7 days, the wound diameter in the FPCL group was significantly smaller than that in the FPCCL group and the control group (Plt;0.01). Under the lightmicroscope, at 4 days postoperatively, the decayed tissue on the surfaces of the recipient wounds in the FPCL group and the FPCCL group was separated from the lower granular tissue in which there were many inflammatory cells, fibroblasts, and new vessels. There was a similar-phenomenon in the control group. Each skin wound in the three groups was only partly keratinocyted at 7 days postoperativel y. The recipient wounds were wholly keratinocyted with when rete ridges observed at 14 and 21 days, but in the control group the wounds were keratinocyted with no rete ridges. Fibers in the new dermis were thin. The OMFs with Brdu appeared in the granular tissue and new dermis at 4, 7, 14, and 21 days postoperatively, which could be illustr ated by the immunohistochemical staining. The positive OMFs and the granular tissue joined in the repair of the skin defe cts without any allergic reaction during the period of the wound healing. Conclusion The oral mucosa fibroblasts as the new seed cells can join i n the repair of the skin defects effectively and feasibly. The fibroblastpopul ated collagen lattices and the fibroblastpopulated chitosan collagen lat tices can repair skin defects effectively and feasibly, too. And the quality of the new skins was better in the two experimental groups than in the control group.