There is a need to improve rapid methods for screening cell-biomaterial interactions. Current methods employ a flat 2D format even though 3D scaffolds are more representative of the tissue environment in vivo and cells are responsive to topological differences of 2D substrates and 3D scaffolds. Thus, combinatorial libraries of 3D porous scaffolds were developed and used to screen the effect of a new amorphous calcium phosphate nanoparticle preparation (CaP) on osteoblast response. Increasing CaP content in poly(-caprolactone) (PCL) scaffolds promoted osteoblast adhesion and proliferation. The CaP-containing scaffolds released calcium and phosphate ions which are known to activate osteoblast function. Scaffold libraries were fabricated in two formats, gradients and arrays, and the magnitude of the effect of CaP on osteoblast proliferation was greater for arrays than gradients. The enhanced response in arrays can be explained by differences in cell culture designs, diffusional effects and differences in the ratio of scaffold mass to culture medium . These results introduce a new gradient library approach for screening large pore 3D scaffolds and demonstrate that inclusion of the novel amorphous CaP nanoparticles enhances osteoblast proliferation in 3D scaffolds. Further, comparison of gradients and arrays suggests that arrays are more sensitive for detecting scaffold effects mediated by soluble factors.
Pub Type: Journals
polymer scaffold, tissue engineering, biomaterials, cell proliferation, calcium phosphate