15:30-16:15

Combinatorial Screening of Stem Cell Response to Gradient Nanobiomaterials

Biomaterials that have gradients in material composition and functional properties may be used to engineer interfaces between two different tissues (soft-to-hard) or for rapid screening of cell response to scaffold properties suitable for tissue engineering applications. This talk reports a method for generating nanofiber scaffold libraries containing gradients in material composition and properties. The method is based on “bi-spinnerret electrospinning” system, wherein the gradients are obtained by using two syringes where one is filled with poly(ε-caprolactone) (PCL) solution and the other with PCL solution containing calcium phosphate particles, nano hydroxyapatite (nHA) for example. The electrospun scaffolds consisted of non-woven PCL nanofibers containing a linear gradient of nHA, as a single scaffold specimen, which facilitated screening of the effect of nHA composition on human bone marrow stromal cells (hBMSCs) response. The formation of nHA gradients was confirmed by thermogravimetric analysis and their morphology was confirmed by scanning electron microscope. The cellular responses were studied by qualitative (fluoresecence imaging) and quantitative (Picogreen DNA assay) analysis. The percent mass of the nHA present in each pre-determined positions across the scaffold libraries were determined in order to quantify the scaffold composition. Cell attachment (SYTOX green staining) and proliferation (dsDNA quantification) were also examined. The cell culture data showed presence of nHA enhanced the cell adhesion and proliferation compared to pure PCL. In addition, an increased alkaline phosphatase activity has observed on the nHA rich side compared to other end of the scaffold specimen (nHA absence side). These data confirm that the hBMSCs respond to material composition and properties along the graded libraries and can be controlled or tuned their growth and differentiation. The combinatorial screening approach can be utilized to systematically identify scaffold composition and properties that optimize cell responses for tissue engineering applications.

Speaker

Prof. Murugan Ramalingam, National Institute of Health and Medical Research, Faculty of Dental Surgery, University of Strasbourg, France

Chair

Dr. Guoping Chen, MANA Principal Investigator, NIMS