Objective To investigate the effects of chitosan on the cell cycle of the human fibroblasts and on the Ki-67 antigen expression in vitro and to investigate the mechanism of chitosan preventing the postoperative tissue adhesion. Methods The cultured fibroblasts were treated for 48 hours with 0，0.01，0.1，1.0，10.0 mg/ml of chitosan, respectively;then, the cell cycle of the fibroblasts was measured by the flow cytometry. The cultured fibroblasts were treated for 24 hours with the chitiosan at the above concentrations; then, the Ki-67 antigen in the cell nucleus was detected with the immunohistochemical staining toobserve its expression. Results The growth of the fibroblastswas obviously suppressed by chitosan, especially in the cell morphology. When the concentrations of chitosan were 1.0 mg/ml and 10.0 mg/ml, the percentages of the fibroblasts in the proliferation stage were 32.3%±5.2% and 14.7%±2.9%, respectively,which were significantly smaller than the percentage of the fibroblasts when the concentration of chitosan was 0 mg/ml (the control group) (41.9%±5.8%， P＜0.05). When the concentrations were 0.01 mg/ml and 0.1 mg/ml, the percentages of the fibroblasts in the proliferation stage were 39.0%±6.0% and 35.5%±3.4%, respectively, which were smaller than that of the control, but not significantly different from that of the control (P＞0.05). When the concentrations of chitosan were 0.1 mg/ml,1.0 mg/ml and 10.0 mg/ml, the percentages of the fibroblasts that had the positiveKi-67 antigen were 37.3%±3.4%, 30.5%±6.2% and 17.8%±3.0%，respectively, which were significantly smaller than that of the control (57.6%±8.9%， P＜0.05). When the concentration was 0.01 mg/ml, the percentage of the fibroblasts that had the positive Ki-67 antigen was 54.1%±8.0%, which was smaller than that of the control, but not significantly different from that of the control (P＞0.05). ConclusionChitosan can inhibit the proliferation of the fibroblasts and increase the percentage of the fibroblasts in the quiescent stage, which can be considered as one of the mechanisms that chitosan can prevent the postoperative tissueadhesion.
Human fibroblasts and human epidermal keratinocytes were used for culture. Chitosan solution were added in the culture solution(DMEM). After 72 hours, the fibroblasts showed rapid growth in the control culture without Chitosan, But the numbers of human fibroblasts from growth was decreased as the concentration of Chitosan was increasing. On the contrary the human epidermal keratinocytes growed more rapidly in the culture with Chitosan than in the culture without Chitosan. The results showed that Chitosan inhibited the growwth of human fibroblast and stimulated the growth of human epidermal keratinocyte .
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.
To observe the effect of chitosan/alginate (CTS/ALG) dressings on wound immersed in seawater. Methods Twenty-five healthy SD rats weighing 250-300 g were used to establ ish skin wound model through cutting 1.8 cm circle-shaped wound along spine bilaterally. The left side served as experimental group, and the right side as control group. The wounds were immersed in the prepared artificial seawater for 1 hour, then the experimental group was treated with CTS/ALG dressings, while the control group was treated with sterile gauze. Gross observation was performed andwound heal ing time was recorded. At 3, 5, 7, 10 and 12 days after operation, 2 cm × 2 cm skin tissues including the wounds were removed and underwent HE staining and immunohistochemistry staining using Envision method. Histological change of wound and expression of EGF receptor (EGFR) and bFGF were observed. Results In the experimental group, wound inflammatory response was sl ight and incrustation shrinked faster, while the incrustation in the control group shrinked slowly. The wound heal ing time of the experimental group and the control group was (11.68 ± 0.57) and (12.51 ± 0.54) days, respectively, suggesting there was a significant difference between two groups (P lt; 0.05). In the experimental group, granulation tissue prol iferation, cell infiltration, collagen tissue prol iferation, wound shrinkage and epithel ization appeared at 3 days after operation; regularly l ined collagen tissue, complete epithel ization and occurrence of skin appendages were observed at 10 days after operation; complete wound heal ing was noted at 12 days after operation; while in the control group, at the corresponding time point, late cell infiltration and epithel ization were observed and granulation tissue with ulcer was noted. Immunohistochemistry observation: high expression of bFGF in vascular endothel ial cells and interstitial fibroblasts and high expression of EGFR in vascular endothel ial cells were observed in the experimental group at 3 and 5 days after operation, and their expressions were low at 7, 10 and 12 days after operation; while in the control group, there were no or low expression of bFGF and EGFR at the same time point. Conclusion CTS/ALG dressings can promote the heal ing of wound immersed in seawater, but its mechanism needsfurther study.
In order to study the effect of chitin and chitosan on the growth of Schwann cell (SC) of rats in vitro, the SC was isolated from sciatic nerve and brachial plexus of new-born rats. After the enzymatic and mechanical dissociation, the cell suspension was vaccinated on chitin membrane and chitosan fluid-coated glass coverslips. Then, the growth of SC was examined at 1, 3, 7 days after culture under light microscope and scanning electron microscope. The results showed that 94 percent of the cell grown from was SC and only 6% was fibroblast (FB), while that of the control SC 71% and FB 29% in population. The number of SC in chitosan suspension was more than that in chitin. Therefore, the conclusion was that the chitin and chitosan was histocompatible to SC, and chitosan suspension was superior to chitin, and both could inhibit the growth of fibroblast.
AbstractThe Staphyloccus epidermidis,pseudomonas aeruginosa,Staphylococcus aureus,Escherichi时 acoli,and Candida al bicans were selected as tested micrcorganisms. According to doubling dilutionrule,the chitosan solution of different dosage was added in the culture solution and kept at 37℃constant tcmporature for 18 hours. The smallest bacteriortatic concentration of the chitosan solutionwas 0.016%for Saphylococcus aureus,0.008%for Staphylococcus epidermidis, 0.032%forEscherichia coli,0...
Chitosan is a kind of biological material with good histocompatibility and gradual biodegradability in vivo. It has no toxicity or side-effect. For its gradual degradation, chitosan and adriamycin were mixed and formed drug delivery system (DDS). The release test of DDS and exudant of DDS in inhibiting OS-116 were examined in vitro. The results were as following: the DDS could release adriamycin in slow and stable way. The SO-116 inhidition rate of the exudant of the DDS on the 1st, 20th, 40th and 60th day was 58.11%, 36.48%, 24.32% and 21.62% respectively. It was concluded that the drug delivery system was a slow release system. It could maintain the concentration of adriamycin in a certain level. It was also suggested that the chitosan was a good carrier for slow release of chemotherapeutic drug in local therapy for postoperative treatment of bone tumor.
An clinical and pharmacokinetic study for a drug delivery system (DDS) of gentamycin-loaded chitosan bar were carried out with the purpose to evaluate its efficacy and giving further data for its clinical applications. Eighteen cases of chronic osteomyelitis were treated by surgical necrectomy with implantation of gentamycin-load chitosan bar in the prepared bone cavity. After operation, the concentration of gentamycin in serum and wound drainage fluid were examined at different times and blood urea nitrogen (BUN) and serum creatinine (Cr) as well. The clinical results were evaluated by the conditions of wound healing and clinical and roentgenographic manifestations. The results showed that the serum gentamycin concentration reached its peak level (0.86 microgram/ml) at 24 hours after operation and lasted for 4 days. No increase in the concentrations of BUN and Cr were observed after implantation. The gentamycin concentration in wound drainage fluid was several hundred times higher than the minimum inhibitory concentration (MIC) for staphylococcus aureus. All of the 18 cases were followed up for 24.8 months (in an range of 6-34 months) 16 patients received initial cure and without any recurrence. So, it could be concluded that the gentamycin-loaded chitosan DDS was a simple and effective method for the treatment of chronic osteomylitis without the necessity to carry out a second operation to remove the drug carrier, and it was sound to popularize its clinical application.
Abstract In order to study the influence of chitosan on bone infection, 27 New-Zealand rabbits were randomly divided into 3 groups. According to the Norden technique, the model of osteomyelitis of the tuberosity of tibia was produced experimentally by injection of staphylococcus aureus.Immediately following injection of the staphylococci, the chitosan gel, acetic acid solution and sterile distilled water were injected into the bones in the 3 groups respectively. The latter two groups were served as control. The severity of the infection was evaluated by clinical symptoms and signs, radiographicdata as well as the bone culture and bacterial counts. Compared the results from chitosan with the other two controls, it was found that the local injection ofchitosan could not reduce the incidence of bone infection, however, it could provide actual improvement when other data were concerned. The effects of chitosangel might be attributed to its bacteriostatic and immunological activity as well as its slow degradation in the body.
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.