Development and Pilot in Vivo Testing of a Protocol for PLGA-Vancomycin Coatings on PTFE Used as Silicone-Implant...

Background and Objectives: Implant-associated complications, including foreign-body responses and infection risk, remain major concerns in reconstructive and aesthetic breast surgery. Antimicrobial polymer coatings have been proposed as potential preventive strategies, but early-stage development requires simple and ethically refined in vivo models. This pilot study aimed to (i) establish a practical workflow for applying PLGA-vancomycin coatings onto PTFE substrates used as experimental analogs for smooth silicone implants, and (ii) develop a small-animal implantation protocol for short-term evaluation of surgical feasibility and local tissue tolerability. Materials and Methods: PLGA microparticles and PLGA-vancomycin microparticles were prepared using a double-emulsion solvent-evaporation method and applied onto PTFE discs. Particle size and polydispersity were assessed based on dynamic light scattering (DLS), and surface charge was measured via zeta potential. A bilateral subcutaneous implantation model was used in four Wistar rats, each receiving a PTFE disc coated with PLGA-only on one side and a disc coated with PLGA-vancomycin on the other. Animals were monitored for postoperative recovery, wound appearance, and general condition. After four weeks, implants and surrounding tissues were harvested for macroscopic and preliminary histological evaluation. Results: Both PLGA-only and PLGA-vancomycin microparticles showed submicron mean hydrodynamic diameters and moderately polydisperse distributions typical for double-emulsion formulations. All animals recovered normally, maintained stable body weight, and exhibited no macroscopic signs of adverse reactions. Preliminary histology showed early fibrous capsule formation with mild inflammatory infiltrate around both types of coated implants, without qualitative differences observed in this pilot setting. Conclusions: This preliminary study demonstrates the feasibility of applying PLGA-only and PLGA-vancomycin coatings onto PTFE implant analogs and establishes a reproducible, minimal-use rat model for short-term evaluation of local tissue tolerability. The protocol provides a practical foundation for future work on coating stability, drug-release kinetics, antibacterial activity, and long-term tissue responses on medical-grade silicone substrates.