In vitro cytocompatibility of porcine type I atelocollagen crosslinked by oxidized glycogen

Oxidized glycogen is used as collagen crosslinker to obtain materials with defined crosslinking degrees. These materials are characterized by their swelling ratio, calorimetric properties and the crosslinking level. Direct and indirect cytotoxicities of the materials obtained as sheets, are evaluated in vitro in cultures of human fibroblasts. The crosslinking degree depends on the ratio CHO glycogen/NH2 glycogen, but whatever this ratio (4.0, 2.0 or 0.4), an important percentage of the introduced CHO groups remains free and these groups are responsible for the cytotoxicity observed with the strongly crosslinked materials. This cytotoxicity appears in cell shape modification and in significant reduction of cell growth. Whatever the crosslinking degree, this toxicity can be suppressed by a single treatment with sodium borohydride, which reduced the remaining free CHO groups in OH functions and stabilizes the materials by a concomitant reduction of the crosslinking imine bonds. After reduction, all materials allow cellular adhesion and proliferation. This new crosslinking method of the collagen by the oxidized glycogen could be promising in the preparation of matrix for in vitro and in vivo tissue regeneration.