Polymeric coatings integrated with drug-loaded micro and nanostructures for bioimplant applications

Biomedical implants play a critical role in restoring tissue function; however, their long-term performance is often hindered by challenges such as infection, inflammation, and poor integration with the host tissue. Recent advances in polymer-based coatings, particularly those incorporating drug-loaded microparticles and nanostructured fillers, have demonstrated outstanding potential in overcoming these limitations. These multifunctional coatings not only enhance biocompatibility and mechanical stability but also enable controlled, localized drug delivery, thereby reducing side effects and improving therapeutic outcomes. This review differentiate three different categories of polymer coatings which can be mostly found in research works including: Natural polymers with their remarkable promise due to their biodegradability, inherent bioactivity, and ability to support cell adhesion and tissue regeneration; Synthetic polymers, which can further contribute tunable degradation rates and mechanical versatility, making them suitable for a wide range of clinical applications; Hybrid/composite coatings, designed through the integration of natural and synthetic polymers, enable the mitigation of key limitations in implant performance and expand the therapeutic scope of implants by providing infection resistance, anti-inflammatory effects, and osteogenic stimulation. Furthermore, this review brings together recent advances in micro and nanoengineered drug-eluting coatings for medical implants, highlighting their design strategies, functional performance, and clinical relevance. Emerging trends and future directions are discussed to underscore the transformative potential of these systems in advancing next-generation implantable medical devices.