Medical device biomaterials and antimicrobial resistance: exploring an overlooked research interface

Modern healthcare depends heavily on polymer-based medical devices (1). Among these, polyvinyl chloride (PVC) is widely used in has become the predominant material used in a wide range of single-use medical devices such as intravenous fluid bags, blood storage bags, urinary catheters, endotracheal tubes, and dialysis circuits.Over six decades, PVC has accounted for an estimated 40%a substantial proportion of medical plastics worldwide, valued for its flexibility, durability, transparency, chemical resistance and relatively low cost (2).However, in clinical practice, PVC-based medical devices are not compositionally or functionally uniform.Medical-grade PVC is formulated with different plasticizerplasticisers (e.g. DEHP, TOTM, DINCH), stabiliszers, and additives, and undergoes diverse manufacturing and steriliszation processes, surface treatment, geometry, fluid contact and duration of clinical use. Throughout this article, we therefore refer to specific PVC-based device types and formulations where possible, and we treat any generalised claims about "PVC" as provisional and device-dependent.While these devices have transformed patient care, they are also implicated incentral to the epidemiology of healthcare-associated infections (HAIs). Indwelling devices, including urinary and vascular catheters and devices used for respiratory support, can provide surfaces for microbial attachment and biofilm formation and are associated with important device-related infectious complicationsIndwelling devices such as urinary catheters, central venous catheters and ventilator circuits account for a substantial amount of device-associated infections, prolonged hospitalization, increased antimicrobial use and excess mortality (3). These infections can prolong hospitalisation and necessitate antimicrobial treatment, placing device-associated infection at an important intersection between infection prevention and antimicrobial use. However, the established risk associated with device use should be distinguished from the question of whether the biomaterial itself independently modifies infection or AMR-related outcomes.Consequently, device-associated infections sit at an important intersection between infection prevention and antimicrobial resistance (AMR).AMR has simultaneously emerged as one of the greatest threats to global health., An estimated 1.14 million deaths were attributable to bacterial AMR globally in 2021, with the burden projected to increase substantially over coming decadescausing an estimated 1.27 million deaths annually (4), and some analyses project that, if current trends continue, deaths from antibiotic-resistant bacteria could surpass those from cancer (5). In response, global efforts to combat AMR have expanded considerably, centered on antimicrobial stewardship, One Health surveillance, infection prevention and control. Within this broader agenda, however, the potential relevance of medical-device biomaterial characteristics to processes associated with AMR has received comparatively limited investigation. Biomaterials interact directly with microorganisms, host tissues and administered drugs, raising questions about whether material-specific properties could influence intermediate processes relevant to infection or antimicrobial exposure. Whether these interactions translate into clinically meaningful AMR outcomes remains uncertain.Despite these advances, one aspect of healthcare has received remarkably little attention within the AMR discourse: the materials through which care is delivered.In this article, we examine three potential pathways through which medical-device biomaterials, with particular attention to PVC, could intersect with processes relevant to AMR. We distinguish established material-and device-related phenomena from indirect or hypothesis-generating downstream links to AMR and identify the principal evidence gaps requiring further investigation. Rather than proposing PVC or other biomaterials as established determinants of AMR, we use these pathways as a framework for examining an underexplored research interface and for considering priorities for future microbiological, pharmacological and clinical research.We propose that medical device biomaterials represent an overlooked upstream component of the AMR ecosystem. Using PVC-based medical devices as an illustrative case because of their widespread use, we aimed to examine four biologically plausible pathways through which biomaterial properties could influence processes associated with resistance. These pathways are mechanistically distinct, but each represents a route through which the device material, rather than the microorganism alone, could plausibly influence infection or resistance outcomes. Although current evidence is insufficient to establish a definitive causal link, this hypothesis warrants further investigation to inform future research, infection prevention strategies and global AMR policy. Table 1 summarises selected device categories, their principal exposure routes and the most relevant biological interactions.PlausiblePotential PathwaysBefore considering biofilms as a potential pathway relevant to AMR, it is essential to distinguish resistance from tolerance and persistence. between AMR, tolerance, and persistence, as these terms describe related but mechanistically distinct phenomena. AMR refers to heritable genetic changes that enable microorganisms to grow or survive at antimicrobial concentrations that would inhibit susceptible strains, typically reflected as an increased minimum inhibitory concentration (MIC), using meansthrough mechanisms including target alteration, enzymatic degradation of drugs, permeability alteration, and efflux pumps (5). Antimicrobial tolerance allows bacterial populations to survive transient exposure to bactericidal antibiotics without an increase in MIC, whereas persistence describes the survival of a small phenotypic subpopulation that can resume growth once anti