Visible Light Chemical Micropatterning Using a Digital Light Processing Fluorescence Microscope

Abstract

Patterning chemical reactivity with a high spatiotemporal resolution and chemical versatility is critically important for advancing revolutionary emergent technologies, including nanorobotics, bioprinting, and photopharmacology. Current methods are complex and costly, necessitating novel techniques that are easy to use and compatible with a wide range of chemical functionalities. This study reports the development of a digital light processing (DLP) fluorescence microscope that enables the structuring of visible light (465–625 nm) for high-resolution photochemical patterning and simultaneous fluorescence imaging of patterned samples. A range of visible-light-driven photochemical systems, including thiol–ene photoclick reactions, Wolff rearrangements of diazoketones, and photopolymerizations, are shown to be compatible with this system. Patterning the chemical functionality onto microscopic polymer beads and films is accomplished with photographic quality and resolutions as high as 2.1 μm for Wolff rearrangement chemistry and 5 μm for thiol–ene chemistry. Photoactivation of molecules in living cells is demonstrated with single-cell resolution, and microscale 3D printing is achieved using a polymer resin with a 20 μm xy -resolution and a 100 μm z -resolution. Altogether, this work debuts a powerful and easy-to-use platform that will facilitate next-generation nanorobotic, 3D printing, and metamaterial technologies.

Light-based vat-polymerization bioprinting

“…Mixed-mode radical polymerizations (for example, thiol-acryloyl polymerization) have yet to be implemented in vat-polymerization-based bioprinting, but this chemistry provides distinct kinetics, mechanical properties and degradation profiles when compared with both step-growth and chain-growth polymerizations 78 . Various photochemistries can also be orthogonally and synergistically combined 79 . Next-generation tissue engineering research necessitates facile synthesis and scalability of photopolymerizable bioresins; in this respect, the thiol-ene reaction has been optimized for controlling physicochemical material properties while retaining superior cytocompatibility and kinetics over other radical-induced photopolymerizations 80,81 .…”

Light-based vat-polymerization bioprinting

“…Mixed-mode radical polymerizations (for example, thiol-acryloyl polymerization) have yet to be implemented in vat-polymerization-based bioprinting, but this chemistry provides distinct kinetics, mechanical properties and degradation profiles when compared with both step-growth and chain-growth polymerizations 78 . Various photochemistries can also be orthogonally and synergistically combined 79 . Next-generation tissue engineering research necessitates facile synthesis and scalability of photopolymerizable bioresins; in this respect, the thiol-ene reaction has been optimized for controlling physicochemical material properties while retaining superior cytocompatibility and kinetics over other radical-induced photopolymerizations 80,81 .…”

Exploring the Structural Space of Chemiluminescent 1,2-Dioxetanes

“…In the merocyanine open form, it steadily decomposes in a CIEEL mechanism, but can be switched back to the spiropyran form with visible light, where it is stable and nonemissive. Photoswitchable chemiluminescent molecules could have interesting applications for advanced types of photoactivatable 3D displays , and photochemical micropatterning techniques …”

“…Photoswitchable chemiluminescent molecules could have interesting applications for advanced types of photoactivatable 3D displays 82,83 and photochemical micropatterning techniques. 84 ■ ENERGY TRANSFER CASSETTES Another strategy to tune the chemiluminescent properties of dioxetanes is to link the dioxetane to a fluorophore in a way that intramolecular energy transfer mechanisms can occur. 45 Schaap showed in a patent that a fluorophore could be linked via the methoxy group on the dioxetane (Figure 8A) 85 and Matsumoto also designed and synthesized a specialized linker for appending fluorophores at the tert-butyl stabilizing group of bicyclic dioxetanes (Figure 8B).…”