Mussel-Inspired Cell/Tissue-Adhesive, Hemostatic Hydrogels\nfor Tissue Engineering Applications

Abstract

The combination of\nmultiple physiological (swelling, porosity,\nmechanical, and biodegradation) and biological (cell/tissue-adhesive,\ncell proliferation, and hemostatic) properties on a single hydrogel\nhas great potential for skin tissue engineering. Adhesive hydrogels\nbased on polydopamine (PDA) have become the most popular in the biomedical\nfield; however, integrating multiple properties on a single adhesive\nhydrogel remains a challenge. Here, inspired by the chemistry of mussels,\nwe developed PDA–sodium alginate–polyacrylamide (PDA–SA–PAM)-based\nhydrogels with multiple physiological and biological properties for\nskin tissue engineering applications. The hydrogels were prepared\nby alkali-induced polymerization of DA followed by complexation with\nSA in PAM networks. The chemical composition of the hydrogels was\ncharacterized by X-ray photoelectron spectroscopy. PDA–SA complexed\nchains were homogeneously dispersed in the PAM network and exhibited\ngood elasticity and excellent mechanical properties, such as a compressive\nstress of 0.24 MPa at a compression strain of 70% for 0.4PDA–SA–PAM.\nThe adhesive hydrogel also maintained a highly interconnected porous\nstructure (∼94% porosity) along with PDA microfibrils. The\nhydrogel possesses outstanding swelling and biodegradability properties.\nOwing to the presence of the PDA–SA complex in the PAM network,\nthe hydrogels show good adhesion to various substrates (plastic, skin,\nglass, computer screens, and leaves); for example, the adhesive strength\nof the 0.4PDA–SA–PAM to porcine skin was 24.5 kPa. The\nadhesive component of the PDA–SA chains in the PAM network\nsignificantly improves the cell proliferation, cell attachment, cell\nspreading, and functional expression of human skin fibroblasts (CCD-986sk)\nand keratinocytes. Moreover, the PDA chains exhibited good hemostatic\nproperties, resulting in rapid blood coagulation. Considering their\nexcellent cell affinity, and rapid blood coagulation ability, these\nmussel-inspired hydrogels have substantial potential for skin tissue\nengineering applications.