Comment by trhway

fish skin (rich in collagen) sounds like a version of collagen patch. And for collagen patch for example https://pmc.ncbi.nlm.nih.gov/articles/PMC3081477/ where despite the "Conclusion" the "Results" show that it helps (and one can also expect that collagen patching is starting point to engineering artificial skin) :

Results:

With two weeks of treatment, 60% of the ‘collagen group’ wounds and only 42% of the ‘conventional group’ wounds were sterile (P=0.03). Healthy granulation tissue appeared earlier over collagen-dressed wounds than over conventionally treated wounds (P=0.03). After eight weeks, 52 (87%) of ‘collagen group’ wounds and 48 (80%) of ‘conventional group’ wounds were >75% healed (P=0.21). Eight patients in the ‘collagen group’ and 12 in the ‘conventional group’ needed partial split-skin grafting (P=0.04). Collagen-treated patients enjoyed early and more subjective mobility.

Conclusion:

No significant better results in terms of completeness of healing of burn and chronic wounds between collagen dressing and conventional dressing were found. Collagen dressing, however, may avoid the need of skin grafting, and provides additional advantage of patients’ compliance and comfort.