WEB High-throughput Screening to elucidate Biomaterial-induced Fibrosis
Nowadays, it is becoming common knowledge that the human body, its tissues and cells react to biophysical and biochemical cues located on biomaterial surfaces. Identifying how these parameters influence cell behavior is crucial and aids in medical implant development. Studies trying to identify these physicochemical properties’ influence on cell behavior investigate only individual material properties, leaving out other variables which are encountered in vivo, where cells always interact with multiple cues simultaneously. We developed a double orthogonal gradient (DOG) platform, which allows us to investigate such complex situations in a high-throughput fashion. The DOGs allow us to screen cell response towards thousands of different situations of combined parameters in single experiments, which will result in the optimization of material properties to enhance biomaterial implant function. Current work includes screening of silicone rubber susceptibility to fibrosis and scar tissue formation. Poly-dimethyl siloxane (PDMS) DOGs are prepared by sequential shielded air plasma oxidation. Primary human dermal fibroblasts (hDFs) are seeded onto the DOGs to study the fibroblast – to – myofibroblast transition, a key factor in scar tissue formation. Every imaginable position on the DOGs has a unique parameter combination, resembling ‘real’, clinically relevant values. Wavy surface topography gradients range from λ = 1 µm – 12 µm and from A = 50 nm – 2,5 nm, the smallest wavelengths corresponding with the smallest amplitudes. Surface stiffness gradients range in Young’s Modulus from ~50 MPa – 500 MPa, and surface ‘wettability’ gradients from 5° – 90° in water contact angle (WCA). As proof – of – concept, we cultured human mesenchymal stromal cells (hMSCs) on the DOGs for 24 hours and assessed cell response with the respect to cell density, spreading, nucleus area, and vinculin expression. The synergistic effect of abovementioned parameters all influenced cell behavior in a different manner. Next steps are identifying regions of interest (ROI) resulting in alterations in collagen (Type-I) deposition and expression of α-smooth muscle actin (SMA) in hDFs, which can further be investigated in more complex studies. The highly efficient cell screening tool we have created with our DOG technology allows us to screen cell response to combined biomaterial surface parameters in high-throughput. It will serve its purpose to facilitate enhanced biomaterial development.