(690h) A High Throughput Combinatorial ECM Screening Platform for Optimizing 3D Microenvironment for Tissue Engineering Applications

Development of optimal biomaterials by modulating cell microenvironment in 3D matrices remains a challenging task in tissue engineering. Cell behavior is directed by cell-cell and cell-ECM interactions which are controlled by composition and concentration of ECM and growth factors.  Identification of synergistic ECM combinations by rational and combinatorial screening of the scaffold, ECM proteins and growth factors will lead to development of optimal biomaterials. Current macro-scale combinatorial screening methods to study the effect of microenvironmental cues are cost-prohibitive, effort intensive and limited by low throughput. To address this challenge, we have developed a high throughput screening platform which utilizes a combinatorial hydrogel printer for generating combinatorial libraries from base scaffold, ECM proteins and growth factors. High throughput combinatorial printer employs a set of syringe pumps for controlling the composition and concentration of components, static mixer system for uniform mixing of materials and translational stage for spatially addressable dispensing of materials into a hydrogel array. A high throughput confocal flatbed scanner was used for imaging hydrogel arrays and cellular responses of proliferation and morphology can be quantified. We studied the endothelial cell responses in composite Collagen I and hyaluronic acid scaffolds. Our results show endothelial cell responses is directed by collagen and hyaluronic acid concentration. Increase in collagen density showed a marked reduction in cell number and addition of hyaluronic acid to collagen does not show marked differences in endothelial cell number. Doping of ECM rich matrigel into collagen scaffolds showed increased cell proliferation and endothelial cell spreading compared to composite collagen I hyaluronic acid scaffolds. The high throughput screening platform is an efficient tool for discovery of synergistic interactions of ECM proteins and soluble factors for optimizing biomaterials for tissue engineering applications.