3D printed antimicrobial PLA constructs functionalised with zinc- coated halloysite nanotubes-Ag-chitosan oligosaccharide lactate.

The control and inhibition of microbial infection are of critical importance for patients undergoing dental or orthopedic surgery. A critical requirement is the prevention of bacterial growth, subsequent bacterial colonization of implant surfaces, and biofilm formation. Among biofilm-forming bacteria, S. aureus and S. epidermidis are the most common bacteria responsible for causing implant-related infections. The ability to produce customized and patient-specific antimicrobial treatments will significantly reduce infections leading to enhanced patient recovery. We propose that 3D-printed antimicrobial biomedical devices for on-demand infection prophylaxis and disease prevention are a rational solution for the prevention of infection. In this study, we modified 3D printed polylactic acid (PLA) constructs using an alkali treatment to increase hydrophilicity and functionalized the surface of the constructs using a suspension of Zinc/HNTs-Ag-Chitosan Oligosaccharide Lactate (ZnHNTs-Ag-COS). The morphologies of printed constructs were analyzed using Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), and chemical analysis by Fourier-transform infrared spectroscopy (FTIR). Assessment of the antimicrobial potential of our constructs was assessed using agar diffusion and biofilm assays. The surface of 3D printed PLA constructs were chemically modified to increase hydrophilicity and suspensions of COS-ZnHNTs-Ag were adsorbed on the construct surface. Surface adsorption of ZnHNTs-Ag-COS on PLA printed constructs was determined to be a function of relative pore size. Morphological surface characterization using SEM-EDS confirmed the presence of the suspension coatings on the constructs, and FTIR analysis confirmed the presence of COS-ZnHNTs-Ag in the coatings. The inhibition of bacterial growth was evaluated using the agar diffusion method. Results obtained confirmed the antimicrobial potential of the PLA constructs (which was a function of the Ag content in the material).