A Combinatorial Approach Towards Functionalizing Copolymers with Effector Molecules that Attenuate Cyto-inflammatory Responses at the Biotic-abiotic Interface

Abstract

AbstractFunctionalized copolymers offer the opportunity for tailored biology, where specific functionalities within these materials can be rapidly engineered on demand. Embedding effector molecules, for example, into these copolymers transforms an otherwise inactive component into a functional matrix for envisioned in vivo applications such as suppression of cellular inflammation/stress or immuno-regulatory implant coating, etc. Furthermore, our ability to utilize these copolymers in both a vesicular/planar configuration, coupled with their versatility in block composition empowers opportunities of utilizing vesicle-encapsulated effector molecules as dedicated drug delivery vehicles with targeting capabilities, or as modalities to replenish exhausted effector molecule stores within planar copolymer thin films. As such, these copolymeric membrane materials may potentially impact multiple medically-relevant fields in both scientific and technological contexts.An important element empowering this transition is the examination of the bio-inert properties of these materials. This includes the interrogation of the stress response of macrophages to the chemical/topographical stimuli presented by these materials. We have previously developed copolymers as neural implant coatings functionalized with a glucocorticoid anti-inflammatory Dexamethasone (Dex) using Langmuir-Blodgett deposition. This technology successfully suppressed, to a significant degree, RAW264.7 macrophage transcriptional machinery of several cytokines including TNFα, Il-6, and Il-12 analyzed using real time PCR (RT-PCR). These findings offered insight into both bio-abio material fabrication, as well as analysis of stress specific gene program activation which may be used to generate principles for optimizing neural implant biocompatibility and chronicity by attenuating innate immune responses.This study has broadened the range of applications of this material via its integration with a combination of intracellular signaling agonists (e.g. Liver X receptor-α/β (LXR α/β)) that function as non-steroidal anti-inflammatories to block transcriptional machinery associated with cell stress among other disorders. Here we demonstrate both planar encapsulation of an additional effector in the form of a robust, cell permeable LXRα/β agonist 3-((4-Methoxyphenyl)amino)-4-phenyl-1-(phenylmethyl)-1H-pyrrole-2, 5-dione using a crosslinked copolymer thin film. In addition, we investigated the underlying mechanisms of the attenuation of cellular inflammation via RT-PCR analysis of the resultant inhibition of lipopolysaccharide (LPS)-stimulated secretion of proinflammatory cytokine in murine macrophages. These advancements may potentially result in multi-functional nanoscale thin films that are chronically active, and can suppress cellular inflammation as implant coatings or bio-inert vesicular carriers of a non-steroidal pharmacological system.