In vitro biocompatibility test for collagen-based dressings

Estimation of Interaction Between Human Keratinocytes and Xenogenic Collagen in vitro

This paper describes the interaction observed between human keratinocytes and xenogenic collagen in vitro modified by HCl. Human keratinocytes were cultivated for 3-10 days, on modified and control support. Their growth, morphology and interaction with support were analyzed. It was found that on both control and experimental (modified) collagen cells proliferated in a similar way. Within 3-10 days, the culture became multilayered and mature and differentiation of cells was visible. Using electron microscope elements of basal membrane interacting with support were seen. On modified support processes of cells penetrating the support are occasionally seen. By use of the immunofluorescent, cytochemical techniques was found the presence of: BP-180 (antigen), beta(4) integrin, laminin 5 and collagen IV, VII, VIIc. On the modified support the above listed elements appeared between 3 and 7 days of culture, whereas on the control between 7th and 10th days. On 10th day of culture, the presence of elements of basal membranes became less evident. Results give some hope for using xenogenic, modified collagen as support of keratinocytes culture in process of human skin engineering.

Cellular proliferation on desamidated collagen matrices

The attachment and growth of human skin keratinocytes (KR) and fibroblasts (FB) on collagen modified by desamidation were investigated. Unlike type I native collagen, desamidated collagen has a sharp iso-ionic pH (5.1) thereby making available either negative or positively charged biomolecules as and when required for a specific bio-application. The cytocompatibility of desamidated collagen prepared from bovine achilles tendons (DCA) and hide trimmings (DCH) was compared with the bovine type I collagen (NC). KR or FB were seeded onto the wells of tissue culture plates coated with the collagen preparations (DCA, DCH and NC). Cellular proliferation on each of these substrates was monitored by reduction of MITT ([3-(4,5-dimethyl-2-thiazolyl)-2,5-dimethyltetrazolium bromide] and by determining the DNA synthesis with [3H]thymidine. In both cases cells proliferated well indicating that DCA and DCH serve as good substrata and are biocompatible. Cell growth occurred without any morphological changes in cell appearance as observed from the phase-contrast microscopy of the cultures, indicating no toxicity of the material during the period studied.