33,34 For the design of ntSPONGE? hyaluronic acid was selected as the most suitable GAG for inclusion in the wound dressing matrix. HA is a natural selleck chemicals Calcitriol component of skin and many connective tissues and known to be a component of healing skin.35�C37 HA is also a hydrogel with inherent absorption properties that are desirable in the wound healing environment for retaining moisture and managing fluid exudate. The combination of HA and collagen fibers has shown advantages such as enhancement of cell migration and division compared with either material alone.18 There are wound dressings and treatments (HYAFF?, Fidia; Hyalofill?, Convatec; Hyalomatrix?, Misonix) based on hyaluronic acid currently on the market today, but not in the proposed combination.
EDC has been shown to modify side-groups on proteins to make them reactive with other side groups and to mediate the ester bond formation between the hydroxyl and carboxyl groups of HA. Therefore, it has been of widespread use in cross-linking of HA, collagen, and gelatin.38 Based on these functions, we utilized EDC in the cross-linking of collagen and HA by the amide and ester bond formation of the side groups. Collagen based products are highly absorptive and maintain a moist wound environment, which promotes autolytic debridement and pain reduction. In the present study, we present an in depth characterization of the biochemical makeup of a novel collagen based sponge wound dressing, ntSPONGE?. The results of the studies presented herein indicate that the novel cross-linked collagen sponge (ntSPONGE?) would be safe and biocompatible for human usage.
Results Cytotoxicity A cultured mouse fibroblast cell line (L929 cells) was used to measure the potential cytotoxic effects of the ntSPONGE material. A score of 3 and above is considered cytotoxic and a score of 0�C2 was considered non-toxic (Table 1). As shown in Table 2, ntSPONGE? material did not induce a substantial cytotoxic response as measured throughout the experiment, in a similar manner as that of the negative control. Cultures exposed to the positive control (CdCl2) exhibited a toxic response while cultures exposed to the black rubber induced a mild toxic response. Table 1. Criteria for evaluating cytotoxicity Table 2. Cytotoxicity of ntSPONGE? Genotoxicity/Mutagenicity Table 3A summarizes the reversion rates (colony count data) for the strains of S.
typhimurium in the presence or absence of ntSPONGE? extract or 2-AA, a known mutagen requiring metabolic transformation (S9). Table 3B summarizes the reversion rates in the presence or absence of ntSPONGE? extract or a known direct-acting mutagen Drug_discovery in the absence of S9. A 2-fold or greater increase in reversion rate was observed for all strains with the appropriate positive control compared with negative controls. Negative control reversion rates for each strain were within expected or lower ranges of historical laboratory data.