Halloysite nanotubes potentiate protein assembly for facile fabrication of nanocomposite thin film and its application in wound dressing

Protein films offer a promising alternative to traditional synthetic polymer materials because of their nontoxicity, biocompatibility and biodegradability, particularly in the biomedical field. However, their practical use has remained a challenge due to their low mechanical strength, poor aqueous stability and high production costs. In this work, we prepared an organic-inorganic protein-based composite film by incorporating vancomycin-loaded halloysite nanotubes (Hal) and bovine serum albumin (BSA) with a facile and biocompatible method. In the composite film, the abundant α-helix structure in BSA was reduced and transformed into a β-sheet-rich phase-transition BSA (PTB), which then interacted with vancomycin-loaded Hal (VHal) through hydrogen bonding to form a cross-linked network structure. Hal can not only reinforce the protein self-assembly via noncovalent interactions to improve the mechanical strength and stability of the protein film, but also act as carriers of antibacterial agents for a sustained drug release system. As a result, the resultant VHal/PTB composite film could completely eliminate Staphylococcus aureus within 30 min and demonstrated excellent biocompatibility. In vivo studies further showed that the composite film could effectively inhibit bacterial infections and accelerate the healing of infected skin wounds in mouse skin, with near-complete wound closure achieved within 12 days. The design strategy of this robust, breathable and biocompatible nanocomposite protein film with antibacterial properties sheds new light on the development of multifunctional wound dressings for infected wound tissue.