Biotinylated Photopolymers for 3D‐Printed Unibody Lab‐on‐a‐Chip Optical Platforms

Abstract

Nowadays, 3D printing represents a consolidated technology enabling the fabrication of rapidly configurable and highly customizable parts. In contrast to traditional subtractive manufacturing approaches, with 3D printing complex designs of virtually any solid shape can be converted into physical objects within few hours starting from a computer-aided design (CAD) model and by depositing material in a layer-by-layer additive fashion. [1] In this respect, no additional costs for multiparts assembling steps are requested and the concept of flexibility characterizing this cost-effective additive manufacturing (AM) approach is strengthened by the constantly growing numberThe present work reports the first demonstration of straightforward fabrication of monolithic unibody lab-on-a-chip (ULOCs) integrating bioactive micrometric 3D scaffolds by means of multimaterial stereolithography (SL). To this end, a novel biotin-conjugated photopolymer is successfully synthesized and optimally formulated to achieve high-performance SL-printing resolution, as demonstrated by the SL-fabrication of biotinylated structures smaller than 100 µm. By optimizing a multimaterial single-run SL-based 3D-printing process, such biotinylated microstructures are incorporated within perfusion microchambers whose excellent optical transparency enables real-time optical microscopy analyses. Standard biotin-binding assays confirm the existence of biotin-heads on the surfaces of the embedded 3D microstructures and allow to demonstrate that the biofunctionality of biotin is not altered during the SL-printing, thus making it exploitable for further conjugation with other biomolecules. As a step forward, an in-line optical detection system is designed, prototyped via SL-printing and serially connected to the perfusion microchambers through customized world-to-chip connectors. Such detection system is successfully employed to optically analyze the solution flowing out of the microchambers, thus enabling indirect quantification of the concentration of target interacting biomolecules. The successful application of this novel biofunctional photopolymer as SL-material enables to greatly extend the versatility of SL to directly fabricate ULOCs with intrinsic biofunctionality.

Fabrication and Functionalization of 3D Printed Polydimethylsiloxane‐Based Microfluidic Devices Obtained through Digital Light Processing

“…Under these conditions, the most frequently used photoinitiators for 3D printing applications are phosphine oxide‐based compounds (TPO and BAPO). [ 45–47 ] These photoinitiators have been reported in the literature for silicone‐based formulations, [ 41,42,48 ] however they do not mix well in the TRAD oligomer. Therefore, we selected a phosphine‐oxide derivate photoinitiator specifically synthesized for this approach (BAPO‐Si, Figure S1, Supporting Information).…”

Progressive 3D Printing Technology and Its Application in Medical Materials

“…It is widely used for fabricating complex devices with functional parts such as valves, lenses and fluidic interconnects (Carve and Wlodkowic, 2018). In the process, a vat of photosensitive polymer resin is selectively exposed to a specifically controlled beam of leaser or light (Credi et al, 2016;Credi et al, 2018). The polymer is polymerized after spatially localized irradiation to fabricate the specific constructions (Credi et al, 2016;Wang et al, 2018a).…”

3D-printed miniaturized fluidic tools in chemistry and biology

“…Several new variants are reported recently. The most interesting of those is biotinylated photopolymer [78]. Due to the extent of applications of biotin in biological and biochemical analysis, this biotinylated polymer can open up a whole new area of applications.…”