Dual enzymatic preparation of flexible biocomplex with full amino-acid composition

Abstract

The preparation of highly versatile flexible biomaterials able to adapt to the complex environment of the human body is an important but challenging task. In this study, a flexible biocomplex (AA-FB) was prepared by combining gelatin, polylysine, and skin using a green enzymatic cascade reaction. Interestingly, none of the raw materials used in the preparation of AA-FB introduced any compounds other than amino-acid composition, which can endow AA-FB with low biotoxicity and allergenicity, along with excellent biodegradability. Morever, AA-FB showed good physical properties: its Young's modulus was 30 times higher than that of pure gelatin hydrogel, and its water vapor transmission rate (2480.12 g/m2·24 h) was also significantly improved. AA-FB could also achieve a bacterial inhibition rate of 91.34 % against S. aureus, much higher than that of skin (28.51 %) and gelatin (41.89 %). Tests of artificial skin show that AA-FB can replace skin tissue as a protective barrier for collagen, blood vessels, and cells. As the new skin tissue is reconstructed, it gradually integrates with the normal tissue of the body until is finally metabolized.