A Combinatorial Photocrosslinking Method for the Preparation of Porous Structures with Widely Differing Properties

A novel method for the simultaneous preparation of a large number of porous polymeric structures with highly differing physical properties is developed. Low molecular weight methacrylate end-functionalized polymers (macromers) are dissolved in ethylene carbonate, cooled to below the melting temperature of the solvent, and subsequently photocrosslinked. The crystallized and phase-separated ethylene carbonate is extracted with water, upon which a porous crosslinked polymer network is obtained. The method is applied to combinatorial mixtures of methacrylate end-functionalized polymers that are relevant in the biomedical field: poly(trimethylene carbonate-dimethacrylate), poly(D,L-lactide-dimethacrylate), and poly(ethylene glycol-dimethacrylate) dissolved in ethylene carbonate at concentrations of approximately 25 wt%. In this manner, 63 different porous polymeric structures with a very wide range of physical properties are prepared simultaneously. In the hydrated state the compressive moduli of the prepared structures range from 0.01 to 60 MPa, as water uptake ranges between 3 and 1500 wt%.