[The influences of cross-linking agent on the composite bio-sponge]

To investigate the influence of cross-linking agents genipin and glutaraldehyde on the composite bio-sponge.

The composite bio-sponge was prepared with the technology of lyophilization. The degree of cross linking was determined using absorptiometry of trinitrobenzenesulfonic acid; the cytotoxicity was tested by MTT assay; the degradation rate in vitro was valuated by lysozyme degradation.

(1) The degree of cross linking of composite bio-sponge crosslinked using genipin and glutaraldehyde increased with the crosslinking time, and reached 26.43% and 54.63% respectively after crosslinking 3 d. (2) The water absorption rate of composite bio-sponge crosslinked using genipin was better than that of crosslinked using glutaraldehyde. (3) In the initial stage of cells incubation, all extracts of composite bio-sponges crosslinked using genipin and glutaraldehyde inhibited the growth of the cells, and the inhibition decreased with the incubation time; but the cytotoxicity of composite bio-sponge crosslinked using glutaraldehyde was higher than that of crosslinked using genipin. (4) After soaking in saline for 4 weeks, the degradation rate of composite bio-sponge crosslinked using genipin or glutaraldehyde was 32.1%, 28.4%, respectively; however, after soaking in saline containing lysozyme for 40 h, the degradation rate of composite bio-sponge was 36.7%, 31.2%, respectively.

Compared with the composite bio-sponge crosslinked using glutaraldehyde, the degree of cross linking and the cytotoxicity of the composite bio-sponge crosslinked using genipin decreased; however, the water absorption rate and the degradation rate increased.