Chemo-Photothermal Therapy of Bacterial Infections by Metal-Organic Framework-Integrated Polymeric Network Coatings

Abstract

Surface modification of biomedical materials and devices using versatile nanocomposite coatings holds great promise for improved functionalities to defend against life-threatening bacterial infections. In this study, a one-step surface modification strategy was developed to deposit gold nanorods (AuNRs)- and curcumin (CUR)-encapsulated zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (AuNRs-ZIF-CUR NPs or AZC) in the phytic acid (PA)-ε-polylysine (Ply) network coatings. In the solution mixture of PA, Ply and AZC, PA interacted with Ply via electrostatic interaction, while it can also bind AZC via metal chelation. The as-formed AZC-PA-Ply aggregates could be deposited onto various substrates via surface adhesion of PA and gravitational effect. The physicochemical and antibacterial properties of the AZC-PA-Ply network coatings on polydimethylsiloxane (PDMS) substrates were assayed. Sustained release of zinc ions and CUR, as well as the contact-killing ability of Ply, endowed the AZC-PA-Ply network coatings with good antimicrobial chemotherapeutic effects. In addition, the embedded AuNRs in the AZC-PA-Ply network coatings exhibited excellent photothermal conversion efficiency for the ablation of bacteria. Upon near-infrared (NIR) laser irradiation, the AZC-PA-Ply-coated PDMS surfaces exhibited strong antibacterial effects by disrupting the membrane integrity and cellular functions of the adhered bacteria. Thus, the AZC-PA-Ply network coatings displayed combined antibacterial chemotherapeutic and photothermal therapeutic effects. Furthermore, the AZC-PA-Ply-coated PDMS substrates exhibited good bacterial infection prevention and biocompatibility in an in vivo implant model. Hence, the versatile AZC-PA-Ply network coatings are potentially useful as a multi-modal antibacterial platform to eliminate infectious bacterial pathogens in biomedical applications.