Novel Hemocompatible Thiol-yne Based Photopolymers Obtained by the Advanced Stereolithography (SLA) Processing with Strongly Improved Surface Smoothness by a Novel Exposition Approach for Anti-aliasing

Purpose The purpose of the work was the developed new photosensitive material dedicated for the blood contact in particular blood pump components. Material Comparable to the thiol-ene polymerization, the thiol-yne reaction follows a step growth mechanism bringing unique properties to this interesting class of materials. Polymerization shrinkage is low, and oxygen inhibition plays only a minor role due to efficient hydrogen abstraction of peroxy radicals from thiols under the simultaneous formation of highly reactive thiyl radicals. One challenging issue of thiol-based formulations is their shelf-life. Dark reactions of thiol, methacrylate and yne, catalysed from basic impurities or traces of metal ions and peroxides, can lead to a significant increase in viscosity during storage time. In order to enable a stable printing of the desired 3D structures, appropriate stabilizers must be found. Methodology Expression of platelet activation markers was measured on CD61 gated objects using PAC-1 antibody for conformational change of glycoprotein IIb/IIIa, and using CD62P for P-selectin. Integrated fluorescence of the activation marker was calculated as a multiplication total of geometric mean fluorescence by percentage of marker-positive objects. Both platelet receptors activation was calculated as measured by PAC-1 and P-selectin (CD62) expression: percentage and mean channel fluorescence of CD62-positive platelets (% and MNF, respectively). The biocompatible resin system, thiol-yne reactive monomers have been evaluated. This reaction is based on a multiple step radical mechanism and finally leads to an addition of two thiol units to one yne functionality forming corresponding thio-ether bonds.