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 .
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.
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.
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.
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.
Objective To verify the technics of inactivating/removing pathogens in medical chitosan derived from shrimp shell. Methods Possible pathogen species were included according to the raw material of shrimp shell used in production, then bacillus cereus, porcine parvovirus (PPV) and pseudorabies virus (PRV) were selected as indicator pathogens.Pathogen solution was prepared in accordance with Technical Standard for Disinfection. The processing procedure of medical chitosan was analyzed to determine whether the alkal ization of chitin and the filter steril ization of chitosan were capable of inactivating/removing pathogens and their efficiencies were tested. Results Bacillus cereus was removed by 8 184 cfu/ mL after alkal ization and 30 818 cfu/mL after filter steril ization. The average logarithm inactivation value (LIV) of PPV and PRV after alkal ization were equal to or above 4.76 logTCID50/0.1 mL and 6.67 logTCID50/0.1 mL, respectively, and their average LIV after filter steril ization were 2.25 logTCID50/0.1 mL and 3.04 logTCID50/0.1 mL. The alkal ization of chitin inactivated/removed indicator pathogens effectively, while the filter steril ization of chitosan removed bacterial effectually but could not inactivate viruses completely. Conclusion The alkal ization of chitin can be used as the technics of inactivating/removing pathogens during the preparation process of medical chitosan to guarantee the safety of the product.
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 effect of intraarticular injection of crosslinked-chitosan in the treatment of knee osteoarthritis in rabbits.MethodsThirty-two New Zealand white rabbits were randomly divided into 4 groups (groups A, B, C, and D; 8 rabbits in each group). The knee osteoarthritis models were prepared by anterior cruciate ligament transection in the left hind in groups A, B, and C. At 4 weeks after operation, the rabbits were received intraarticular injection of 0.6 mL crosslinked-chitosan in group A, 0.3 mL chitosan (once per 2 weeks, for twice) in group B, and 0.3 mL saline (once per 2 weeks, for twice) in group C. The rabbits in group D were treated with sham operation in the left hind, and received intraarticular injection of 0.3 mL saline (once per 2 weeks, for twice). At 8 weeks, the macroscopic observation, histological examination (HE staining, Safranin-fast green double staining, and Mankin score), scanning electron microscopy (SEM) observation, and immunohistochemical staining of collagen type Ⅱ were performed.ResultsMacroscopic and SEM observations showed that the cartilage in group D was basically the same as normal and better than that in groups A and B, and the abrasion of cartilage in group C was the most serious. The histological observation results in groups A and B were slightly similar and better than those in group C, but not up to the structure of group D. The macroscopic score and Mankin score of groups B and C were significantly higher than those of group D (P<0.05), and there was no significant difference between group A and group B (P>0.05). Immunohistochemical staining results showed that the collagen type Ⅱ positive percentage of chondrocytes was significantly higher in group D than that in groups B and C, and no significant difference was found between group A and group B (P>0.05). ConclusionThe crosslinked-chitosan can significantly improve the osteoarthritis of the rabbit knee, delay the pathological changes of osteoarthritis, and decrease the frequency of injection.
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...