Liquid acrylate-endcapped biodegradable poly(epsilon-caprolactone-co-trimethylene carbonate). II. Computer-aided stereolithographic microarchitectural surface photoconstructs.

Advanced micromedical devices may require computer-aided photofabrication, by which microarchitectural surface design and entire macroshaped body design are feasible. Liquid acrylate-endcapped poly(epsilon-caprolactone-co-trimethylene carbonate)s, poly(CL/TMC)s, prepared using trimethylene glycol (TMG) or poly(ethylene glycol) (PEG) as an initiator and an acrylate group for subsequent terminal capping, were used as photocurable copolymers. The stereolithographically microarchitectured photoconstructs were prepared using a custom-designed apparatus with a moving ultraviolet (UV) light pen driven by a computer-assisted design program. The prepared photoconstructs included microneedles, a microcylinder and microbanks on surfaces. In vitro hydrolytic degradation proceeded with surface erosion when hydrophobic TMG-based photocured copolymers were employed, whereas very fast degradation of hydrophilic PEG-based photocured copolymers probably via concerted actions of surface erosion and bulk degradation was observed. In vivo hydrolytic behavior upon subcutaneous implantation in rats indicated that surface erosion proceeded for TMG-based photoconstructs. Anti-inflammatory drug (indomethacin) loading into microneedle-structured surfaces minimized inflammatory reactions. The possible biomedical microarchitectural three dimensinal in biomedical application photoconstructs was discussed. Copyright 2002 Wiley Periodicals, Inc.