Investigated the changes of crosslinking index, swelling ratio, degradation rate and cytotoxicity of genipin crosslinked gelatin accompany with crosslinking time. 1% genipin crosslinked gelatin were divided into 7 groups by crosslinking time: 10 min group, 30 min group, 1 h group, 2 h group, 12 h group, 24 h group, 72 h group. The results proved that genipin could crosslink gelatin effectively. Accompany with increasing of crosslinking time, crosslinking index increased, and swelling ratio, degradation rate decreased. In 10 min group, crosslinking index was low(26.7%), swelling ratio was high, (265%), completely degraded within 1 week. This indicated that biomaterials of 10 min group was instable and degraded easily. Compared with 10 min group, biomaterials of 30 min group changed significantly with crosslinking index(45.7%), swelling ratio (206%) and degration rate (completely degraded between 4 weeks and 8 weeks). This indicated that genipin could change the properties of gelatin within 30 min. Biomaterials after 30 min, crosslinking index increased, and swelling ratio, degradation rate decreased gradually accompanied with increasing of crosslinking time. Biomaterials of 72 h, crosslinking index was 73.1%, swelling ratio was 152%, and degradated 18.9% after 12 weeks. RGR (relative cell growth rate) of every group measured by MTT assay changed between 87.9% and 105.4%, indicated that the cytotoxicity of genipin crosslinked gelatin was very low.
Animals ; Biodegradation, Environmental ; Cell Survival ; drug effects ; Cricetinae ; Cricetulus ; Cross-Linking Reagents ; chemistry ; toxicity ; Gelatin ; chemistry ; Iridoid Glycosides ; Iridoids ; chemistry ; toxicity ; Time Factors

Two kinds of gel materials were prepared from silk fibroin with polyepoxy compound at subfreezing temperature and higher temperature. In order to evaluate the feasibility of their application in biomaterials, we tested the cytotoxicity of silk fibroin gels by detecting the effect of the extracted liquid on the cell relative proliferation rate of L-929 mouse fibroblasts. The results indicated that both of the gel materials displayed high relative proliferation rate and grade 1 cytotoxicity, being in the allowed range of medical application. The cytotoxicity tests on polyepoxy compound and glutaraldehyde were conducted too, and the cytotoxicity of polyepoxy compound was obviously lower than that of glutaraldehyde. Polyepoxy compound can be used as a more safe cross-link reagent for silk fibroin modification.
Animals ; Biocompatible Materials ; chemistry ; Bombyx ; chemistry ; Cross-Linking Reagents ; chemistry ; Fibroblasts ; drug effects ; Fibroins ; chemistry ; Gels ; chemical synthesis ; toxicity ; Mice ; Polyethylene Glycols ; chemistry ; Temperature

Hyaluronan acid sodium gels are used in ophthalmic surgery, orthopedic treatment and cosmetic surgery. In 2009,there were 12 domestic manufacturers in China producing 33 kinds of products. 23 kinds of imported products were allowed by SFDA to sale in the meantime. Since manufacturers use different production processes, product performances are quite different. According to the GB/T 16886. 1-2001, we designed a pilot program to evaluate the sodium hyaluronate gel products comprehensively in this paper. The results showed that, except chromosome aberration test of gel A and subchronic systemic toxicity of gel C appeared positive, the remaining samples of the test results were negative. This article provides a reference to write standard of cross-linked hyaluronic sodium gel and the revision of standard YY0308-2004.
Animals ; Biocompatible Materials ; standards ; Cross-Linking Reagents ; chemistry ; Gels ; Hyaluronic Acid ; standards ; Mice ; Pilot Projects ; Quality Control ; Rabbits ; Rats ; Rats, Sprague-Dawley ; Toxicity Tests ; methods

We investigated the influence of glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) polymorphisms upon DNA-protein crosslinks (DPC) induced by benzo[a]pyrene (B[a]P) in cultured human lymphocytes. Lymphocyte samples were collected from 30 healthy nonsmoking hospital administrative workers. DPC was detected with KCl-SDS assay and the distributions of GSTM1 and GSTT1 were determined by polymerase chain reaction. B[a]P was found to induce a significant dose-responsive increase in cytotoxicity and DPC regardless of the genotypes (p<0.05). We did not find statistically significant genetic modification effect of GSTM1 and GSTT1 polymorphisms in the cytotoxicity and DPC formation (p>0.05). In terms of the genes examined, the level of cytotoxicity and DPC formation were found to be highest in the GSTM1-null and GSTT1-null cells. In conclusion, B[a]P induced a significant increase in the cytotoxicity and the level of DPC formation in cultured human lymphocytes. Our findings suggest that DPC could be used as a biomarker of B[a]P exposure.
Adult ; Benzo(a)pyrene/*toxicity ; Cells, Cultured ; Cross-Linking Reagents/*toxicity ; DNA-Binding Proteins ; Dose-Response Relationship, Drug ; Genotype ; Glutathione Transferase/*genetics ; Humans ; Lymphocytes/cytology/drug effects/*physiology ; Male ; Polymorphism, Genetic

To investigate whether a series of water-soluble cross-linked chitosan derivates synthesized in the guide of imprinting technology could be used as a uranium chelating agent to protect cells exposed to depleted uranium (DU), the imprinted chitosan derivates with high UO2(2+) chelating ability were screened, and cell model of human renal proximal tubule epithelium cells (HK-2) exposed to DU (500 micromol.L-1) was built, chitosan derivates (400 mg.L-1 ) was added to test group and diethylenetriaminepentaacetic acid (DTPA, 50 mg.L-1) was added to positive control group. The results showed that three Cu2+ imprinted chitosan derivates had higher uranium chelating ability (>49 microg.mg-1) than chitosan and non-imprinted chitosan derivates. Compared to the cells exposed to DU only, survival of cells in group added chitosan derivates rose up significantly (increased from 57.3% to 88.7%, and DTPA to 72.6%), and DU intracellular accumulation decreased, membrane damage and DNA damage also eased. Among the imprinted chitosan derivates, Cu2+ imprinted penta dialdehyde cross-linked carboxymethyl chitosan (Cu-P-CMC) was the best, and better than DTPA. From ultrastructure observation, the DU precipitates of test group added Cu-P-CMC were most grouped in a big hairy clusters in a string together outside cells. It is possible that the DU-chitosan derivates precipitates are too big to enter into cells, and from this way, the DU uptake by cells decreased so as to detoxication.
Antioxidants ; metabolism ; Apoptosis ; drug effects ; Cell Line ; Cell Survival ; drug effects ; Chelating Agents ; administration & dosage ; chemistry ; pharmacology ; Chitosan ; administration & dosage ; analogs & derivatives ; chemistry ; pharmacology ; Copper ; chemistry ; pharmacology ; Cross-Linking Reagents ; administration & dosage ; chemistry ; pharmacology ; DNA Damage ; drug effects ; Epithelial Cells ; cytology ; ultrastructure ; Humans ; Inactivation, Metabolic ; Kidney Tubules, Proximal ; cytology ; ultrastructure ; Microscopy, Electron, Transmission ; Uranium ; toxicity ; Water