To assess the in vitro cytotoxicity by indirect contact, alamarBlue TM assays were performed on extracts from the 3.6 wt% TR-CP gels (pH = 7, reconstituted in sterile cell media). L929 fibroblasts were cultured in the extracts and incubated for either 2 days or 7 days. Percent viability was calculated with respect to a sterilized cell culture media control. The day 1-5 extracts from the TR-CP all supported L929 fibroblasts well with high viability for both the 2-day (> 84%, Fig. ) and 7-day cultures (> 89%, Fig. ).