Gene Reconstruction Spandex with Intrinsic Antimicrobial Activity

Abstract Polyhexamethylene guanidine hydrochloride (PHMG) was used as a functional “gene” to replace the diamine in ordinary spandex, and a “gene reconstruction” spandex (GRS) spinning solution was synthesized. Mixing a small amount of GRS spinning solution with ordinary spandex spinning solution, composite spandex (CS) with intrinsic antimicrobial activity was obtained by a dry-spinning process under a normal spinning condition. The TEM results indicated that PHMG in the GRS molecular chain was uniformly distributed in CS in a granular shape with 10-100 nm diameter and was aligned along the fiber axial direction with a chain-like structure. The inhibition rates of CS (containing 0.5 wt% PHMG) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) exceeded 99.99%. CS maintained excellent antibacterial properties after soaking in acetic acid solution at pH 3 for 45 min at 95 °C and showed strong intrinsic antimicrobial characteristics. Confocal laser scanning microscopy demonstrated that bacteria was quickly adsorbed on the surface of CS fiber, the cell membrane was damaged, and gradually bacteria died. The molecular simulation indicated that the positive charges accumulated on the PHMG surface, providing the driving force to attract bacteria with negative charge on the cell membrane phospholipid layer. TGA, DSC, XRD and mechanical property analysis confirmed that the corresponding performances of CS were better than those of ordinary spandex without GRS. In summary, the as-prepared CS by “gene reconstruction” eliminated the exudation problem of antibacterial agents in the traditional antimicrobial materials.