Background and Objectives: Photochemical tissue bonding (PTB) using rose bengal (RB) in conjunction with light is an alternative technique to repair tissue without suturing. It was recently demonstrated that laser‐irradiated chitosan films, incorporating RB, bonded firmly to calf intestine in vitro. It is thus required to investigate the possible cytotoxic effects of the RB–chitosan adhesive on cells before testing its application to in vivo models.

Materials and Methods: Adhesive films, based on chitosan and containing ∼0.1 wt% RB were fabricated. Their cytotoxicity was assessed by growing human and murine fibroblasts either in media in which adhesive strips had been incubated, or directly on the adhesive. The adhesive was either laser‐irradiated or not. Cells were stained after 48 hours with Trypan blue and the number of live and dead cells was recorded for cell viability.

Results: Murine and human fibroblasts grew confluent on the adhesives with no apparent morphological changes or any exclusion zone. Cell numbers of murine fibroblasts were not significantly different when cultured in media that was extracted from irradiated (86 ± 7%) and non‐irradiated adhesive (89 ± 4%). A similar result was obtained for the human fibroblasts.

Conclusions: These findings support that the RB–chitosan films induced negligible toxicity and growth retardation in murine and human fibroblasts.