Abstract 11470: Polymer Microarrays - A Novel High-Throughput Screening System to Rapidly Identify Substrates for Engineering Bioartificial Aortic Valves
Background: Aortic valve (AoV) stenosis is a widely diffused pathology resulting from calcium deposition inside leaflets. This requires native valve substitution with mechanical or bio-prosthetic implants. The currently employed devices have serious limitations that include the need for anti-coagulation treatments and time restricted durability. Therefore, the identification of biomaterials promoting the physiological growth of the aortic valve interstitial cells (aVICs) is of interest for the manufacture of fully tissue engineered heart valve (TEHV) prostheses which may be used as definitive ’living’ replacements in cardiac valve surgery.
Methods and Results: In the present study, we used a “high-throughput” material array screening system to identify Polyacrylate (PA) substrates for this application. Arrays were fabricated by spotting a PA library (n=300) onto agarose-coated glass slides by direct contact printing (QArraymini with aQu solid pins from K2785, Genetix, UK). Each polymer was printed in quadruplicate onto the arrays. Primary human aVICs, obtained by enzymatic dissociation of the non-calcified portion of AoV leaflets removed during valve replacement surgery, were expanded for two passages on plastic before seeding and cultured onto the arrays (3x105 cell/array) for 72 hours (n=3 independent aVICs lines). To assess cell adhesion and cell spreading, immunofluorescence with anti-Vimentin, -Collagen-I and -αSMA antibodies were performed in conjunction with nuclear and stress fibers staining, followed by computer-assisted fluorescence quantification (Cell Profiler software). The results indicated eight candidate PAs promoting aVICs growth, although with different modalities (number of cells per PA spot, based on nuclei automatic counting, ranging from 18±3 to 60±6, mean±SE; n>14 replicates/polymer). In addition, the adhesion onto these substrates promoted various expression levels of αSMA and Vimentin, and caused different degrees of cytoskeleton organization and polymerization.
Conclusions: Our data show, for the first time, the applicability of a high-throughput screening system to identify suitable materials to grow human aVICs and generate fully TEHV prostheses.
- © 2013 by American Heart Association, Inc.