3.11.1. Subcutaneous implantation

A rat subcutaneous implantation model was used to assess the in vivo biodegradation and biocompatibility of the engineered bioadhesives. All animal experiments were reviewed and approved by Institutional Animal Care and Use Committee (ICAUC; protocol #2018‐076) at UCLA (Los Angeles, CA). Male Wistar rats (200–250 g) were put under general anesthesia (isoflurane, 2.5%). After inducing anesthesia, eight (8 mm) incisions were made on the posterior dorsomedial skin and small lateral subcutaneous pockets were prepared by blunt dissection. Cylindrical hydrogel samples were weighed, lyophilized for 24 h, and reweighed. Afterward, the lyophilized samples were sterilized via exposure to UV light for 10 min. The samples were subcutaneously implanted in rats. The animals carrying the hydrogel implants were euthanized on Days 7, 28, and 56 post‐surgery. The hydrogel samples were explanted and used for histopathological or degradation analyses.