Biocompatibility evaluation of laser-induced AAm and HEMA grafted EPR. Part 1: In-vitro study

Area of Science:

• Materials Science
• Biomaterials Engineering
• Surface Chemistry

Background:

• Ethylene-propylene rubber (EPR) is a versatile polymer with potential biomaterial applications.
• Surface modification is crucial for tailoring biomaterial properties and cell interactions.
• Controlling surface morphology can influence biological responses.

Purpose of the Study:

• To surface graft acrylamide (AAm) and 2-hydroxyethyl methacrylate (HEMA) onto EPR using CO2-pulsed laser.
• To characterize the morphology and chemical composition of the modified EPR surfaces.
• To evaluate the in-vitro adhesion and spreading of alveolar macrophages (AMs) on the modified surfaces.

Main Methods:

• Surface grafting of AAm and HEMA onto EPR using CO2-pulsed laser.
• Characterization using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA), and Attenuated Total Reflectance Infrared (ATR-IR) spectroscopy.
• In-vitro evaluation of alveolar macrophage adhesion and spreading via hemocytometry and SEM.

Main Results:

• Fractal-patterned poly(AAm) and poly(HEMA) grafts were successfully formed on the EPR surface.
• Fractal regions showed significant grafting, while non-fractal regions had negligible amounts.
• Modified surfaces exhibited altered AM adhesion and spreading compared to unmodified EPR, with lower cell density and spreading on moderately grafted samples.
• Unmodified EPR promoted greater AM adhesion, spreading, and filopodia formation.

Conclusions:

• CO2-pulsed laser grafting creates fractal surface morphologies on EPR with tunable hydrophilic/hydrophobic properties.
• Surface morphology and graft level significantly influence alveolar macrophage behavior.
• The fractal surfaces offer potential for developing advanced biomaterials with controlled cellular interactions.