This study fabricated polyacrylic acid hydrogels via UV-initiated radical polymerization. Two types were constructed: physically cross-linked P-PAA (via intermolecular hydrogen bonds) and chemically cross-linked C-PAA (using MBA as crosslinker). Both were prepared through simple, mild procedures suitable for scale-up. SEM showed P-PAA had a loose, large‑pore network, while C‑PAA exhibited denser architecture due to higher covalent crosslinking. Mechanical tests revealed compressive strengths of 0.21 MPa (P‑PAA) and 0.54 MPa (C‑PAA), indicating superior resistance for the chemically crosslinked system. Tissue adhesion tests confirmed that abundant carboxyl groups on PAA formed strong hydrogen bonds with skin surface amino groups, enabling tight adherence to porcine skin even under bending and torsion. Biosafety evaluation via CCK‑8 and live/dead staining demonstrated no cytotoxicity and significant promotion of NIH‑3T3 fibroblast proliferation for both hydrogels. In a rat full‑thickness skin incision model, compared to sutures, PAA dressings remarkably reduced inflammation, promoted angiogenesis and fibroblast proliferation, accelerated wound closure, optimized collagen arrangement, and alleviated scar formation. Benefiting from reversible hydrogen‑bond networks, P‑PAA offered shear‑thinning injectability, self‑healing, and controllable pain‑free debonding, avoiding secondary injury during dressing changes. In contrast, C‑PAA provided higher mechanical strength and adhesion, suitable for wounds under high tension. The two hydrogels complement each other, covering applications from first aid and field care to clinical surgery. With convenient operation and low cost, they address the shortcomings of existing medical adhesives in adhesion, biocompatibility, and degradability, showing promising clinical translation prospects.

Pengfei Zou, Dinghe Sha, Hongye Tang, Shitong Peng, Tao Tao, Ruoxi Jia. Injectable polyacrylic acid hydrogels with dual crosslinking networks for wound closure and healing. Academic Journal of Materials & Chemistry (2026), Vol. 7, Issue 1: 121-129. https://doi.org/10.25236/AJMC.2026.070117.

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