Insights into the interactions between collagen and a naturally derived crosslinker, oxidized chitosan oligosaccharide

Abstract

Collagen has been widely applied to biomaterials. However, it must be chemically fixed before it can be used. The aim of this work is to study on the crosslinking effect of a naturally derived oxidized chitosan oligosaccharide (OCOS) on collagen type I. The physicochemical properties and biocompatibility of the crosslinked collagen (OCOS-Col) were evaluated. The FTIR spectroscopy showed that crosslinking via OCOS had no impact on the structural integrity of collagen. DSC and TG tests showed that the thermal stability of crosslinked collagen was improved significantly, while the crosslinking density test indicated that the amino groups of collagen could predominantly react with the available aldehyde groups of OCOS. The mechanical properties, hydrophilicity, and enzymatic degradation test showed that the crosslinked material had improved properties. However, the porosity test showed that the crosslinked material was more compact, which was consistent with the AFM observation that crosslinked collagen revealed a denser network structure. Cytotoxicity test showed that the crosslinked collagen was conducive to cell adhesion, growth, and proliferation. In conclusion, this work reveals that OCOS stabilized collagen as a crosslinker, preserved its triple helical structure, and reserved its good biocompatibility. OCOS was proven to be a safe and reliable crosslinker for collagen.

Is Dialdehyde Chitosan a Good Substance to Modify Physicochemical Properties of Biopolymeric Materials?

“…They reported that dialdehyde cellulose did not have any observable impact on the cytotoxicity of hydrogels and all tested materials were nontoxic after 48 and 96 h of cell culture [ 67 ]. Following to Chen et al [ 68 ], membranes based on collagen, cross-linked with oxidized chitosan oligosaccharide, have a good biocompatibility. They evaluated toxicity of the materials by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay with L929 fibroblast cells.…”

“…They evaluated toxicity of the materials by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay with L929 fibroblast cells. It was noticed that higher amount than 2% of cross-linking agent, increased cytotoxicity effect of the material, however thanks to confocal microscopy they observed a little adverse effect on cell growth and proper proliferation of the cells was visible [ 68 ]. The fibroblast cells grow well with proper morphology on the surface of the membranes cross-linked with oxidized chitosan oligosaccharide [ 68 ].…”

“…As it is known, some compounds containing aldehyde groups are harmful for cells, due to their possible toxicity and leakage of unreacted cross-linker molecules in vivo (formaldehyde, glutaraldehyde, or glyceraldehyde can be an examples [ 9 , 68 ]). Thus, novel and safer cross-linking agents, obtained from natural organic compounds with dialdehyde groups are extensively investigated.…”

“…Thus, novel and safer cross-linking agents, obtained from natural organic compounds with dialdehyde groups are extensively investigated. Unlike that of formaldehyde, glutaraldehyde and glyceraldehyde, according to Chen et al [ 68 ] and Hu et al [ 26 ], studied dialdehydes (oxidized chitosan oligosaccharide, dialdehyde chitosan, dialdehyde starch, dialdehyde cellulose, dialdehyde alginate) have a skeleton structure, which could avoid the harmful influence of aldehyde groups.…”

Factors affecting thermal stability of collagen from the aspects of extraction, processing and modification

“…Recently, dialdehyde compounds derived from natural biomass with good biodegradability and low toxicity have attracted increasing attention. The thermal stability of collagen have been demonstrated to be improved by dialdehyde compounds such as oxidized glycogen, oxidized chitosan oligosaccharide, dialdehyde cellulose, oxidized sodium alginate and dialdehyde carboxymethyl cellulose (DCMC) [215][216][217][218]. A collagen cryogel was prepared by Tan et al [219] using dialdehyde carboxymethyl cellulose to crosslink collagen in solution at different DCMC/Col weight ratios of 0.0-0.2% with constant collagen concentration of 5 mg/ml.…”