TAILORING SURFACE PROPERTIES TO CONTROL INTERACTIONS WITH BIOLOGICAL ENTITIES USING POLYMER ARCHITECTURES

Abstract

In the biomedical field, controlling interactions of surfaces with proteins, bacterial and mammalian cells is a key factor for a wide range of applications such as tissue engineering, antibacterial coating and implantable biomaterials. Interactions of these biological entities with surfaces can be largely affected by surface physical properties of the substrates, such as wettability, charge, morphology and stiffness. However, due to their interrelated nature, tuning these surface properties individually is difficult. This may hamper accurate interpretation of their effects. In this thesis, different polymer architectures were fabricated to tailor surface properties with minimal cross-parameter influence. To control interactions with proteins, a strategy to modulate surface charge was developed based on immobilization of zwitterionic polymer brushes via surface-initiated atom transfer radical polymerization. To achieve a more refined control over interactions with biological entities, a multi-parametric study was conducted using layer-by-layer assembled polyelectrolyte architectures. Such architectures allow parallel control over both surface charge and wettability. Using this system, interactions with key proteins, bacteria and mammalian cells can be manipulated. With an additional crosslinking step, a system that can simultaneously enhance host cell adhesion and suppress bacterial adhesion was developed, which can potentially be useful coatings for implanted biomaterials in tissue engineering applications.