Fabricating small-scale, curved, polymeric structures for biological applications using a combination of photocurable/thermocurable polydimethylsiloxane and phase interactions

This paper describes an easy-to-handle technique for creating curved, millimetrically scaled polymeric structures in order to develop in vitro cell culture devices for biologically relevant applications. For the master mold in this study, the authors used UV-activated photocurable polydimethylsiloxane (PDMS). This product can readily be used to create millimetrically scaled pattern molds by controlling droplet contact angles during deposition onto a flexible paper-based substrate that has been prepatterned with ink/wax. Resultant desired patterns can be transferred onto thermocurable PDMS as arrays of wells for biological applications. By combining photocurable and thermocurable PDMS manufacturing processes, this approach endows PDMS-based structures with unique controllability in terms of size, pattern, and curvature. Providing such features enhances the biocompatibility and practicality of devices so manufactured in that they mimic the natural topography of the extracellular matrix. Additionally, three-dimensional cell culturing and immunofluorescent staining can be demonstrated on this biomimetic platform. This manufacturing method takes only several minutes to complete and does not require complicated facilities in order to fabricate PDMS-based biomedical devices. We believe that this method would be very useful for rapid, economical fabrication of cell-focused assay platforms, which would be particularly useful in resource-limited settings.