Impact of Surface Biofouling on Controlled Drug Release from Conductive Polymer Films and Its Mitigation Using Lubricin (Proteoglycan 4) Antifouling Coatings

Drug delivery platforms are frequently susceptible to nonspecific adsorption of biological materials upon contact with biological fluids that can interfere with the controlled release of drugs, affecting both the rate and amount of drug released. To improve the controlled release efficiency of drugs within biological environments, lubricin (also known as PRG4) antifouling coatings were applied to control the release of poly(3,4-ethylenedioxythiophene) (PEDOT) films doped with the model drug phenol red. Drug release experiments comparing uncoated and lubricin-coated PEDOT were performed in nonfouling PBS buffer to assess the impact of lubricin coating on the release of drug from the films, while identical experiments were performed in concentrated solutions of highly fouling proteins to investigate lubricin's capacity to mitigate the effects of surface biofouling on the drug release properties. These experiments revealed that lubricin coating did not create a physical or diffusional barrier to the release of phenol red from PEDOT under nonfouling conditions. Likewise, within a highly fouling protein solution, the lubricin-coated PEDOT films showed greatly enhanced phenol red release compared with uncoated films under passive conditions and active release under an applied negative potential. This greater phenol red release from the lubricin-coated PEDOT was attributed to lubricin's capacity to protect the surface from fouling by nonspecifically adsorbed proteins, which impede the release of phenol red. This study demonstrated that lubricin can effectively improve drug release from PEDOT films in highly fouling environments, resulting in more accurate and reliable dosing.