Early Biocompatibility of Brown Macroalgal Scaffolds in a Splinted Full-Thickness Rodent Wound Model: A Pilot Study

Wounds are an increasing clinical and socioeconomic burden motivating the development of sustainable and biocompatible biomaterials for wound healing. Collagen-based extracellular matrix products can improve healing but are limited by cost and ethical or cultural constraints. Cellulose-rich macroalgal matrices offer a potential sustainable alternative. This pilot study evaluated the biocompatibility and wound-healing performance of brown macroalgal scaffolds. Scaffolds derived from Laminaria digitata (LD) and Saccharina latissima (LS) were produced using the visible-light method. Indirect cytotoxicity was assessed in keratinocytes, and in vivo effects were evaluated in a splinted dorsal excisional wound model in Sprague Dawley rats (n = 24), comparing LD, LS, bacterial cellulose (a CACS), and standard of care (SOC). The LD and LS extracts were non-cytotoxic, and no adverse reactions were observed in vivo. Wounds treated with LD, LS, and the SOC showed faster wound closure than the CACS at intermediate timepoints. Inflammation and foreign-body response scores were low and comparable across all groups. The LD showed significantly greater fibroblast infiltration than the CACS at day 7, and at day 14, the LD group exhibited the highest collagen area fraction. These findings indicate that LD and LS scaffolds are non-cytotoxic, are well-tolerated in vivo, and influence wound repair in full-thickness wound models, warranting further study as sustainable biomaterial.