A Multidisciplinary Experiment to Characterize Antifouling Biocompatible Interfaces via Quantification of Surface Protein Adsorption

Novel biomaterial development is a rapidly growing field that is crucial because biomaterial fouling, due to rapid and irreversible protein adsorption, leads to cellular responses and potentially detrimental consequences such as surface thrombosis, biofilm formation, or inflammation. Therefore, biomaterial technology's fundamentals, like material biocompatibility, are critical in undergraduate education. Exposing undergraduate students to biomaterials and biomedical engineering through interdisciplinary experiments allows them to integrate knowledge from different fields to analyze multidisciplinary results. In this practical laboratory experiment, undergraduate students will characterize surface properties (contact and sliding angle measurements) for the antifouling polydimethylsiloxane (PDMS) polymer using a goniometer and a smartphone, as well as quantify protein adsorption on antifouling surfaces via a colorimetric assay kit to develop their understanding of antifouling surface characteristics, UV-vis spectroscopy, and colorimetric assays. The antifouling PDMS polymer is prepared by silicone oil infusion and compared to untreated control PDMS. The polymer hydrophobicity was demonstrated by static water contact angles of ~99° and 102° for control and antifouling PDMS surfaces, respectively. The control PDMS sliding angle (>90°) was significantly reduced to 9° after antifouling preparation. After 24 h incubation of polymer samples in a 200 mg/mL bovine serum albumin (BSA) solution, the surface adsorbed BSA was quantified using a colorimetric assay. The adsorbed protein on the fouling PDMS controls (29.1 ± 7.0 μg/cm2) was reduced by ~79% on the antifouling PDMS surface (6.2 ± 0.9 μg/cm2). Students will gain experience in materials science, biomedical engineering, chemistry, and biology concepts and better understand the influence of material properties on biological responses for biomaterial interfaces.