Synthesis of colloidal microgels using oxygen-controlled flow lithography

Abstract

We report a synthesis approach based on stop-flow lithography (SFL) for fabricating colloidal microparticles with any arbitrary 2D-extruded shape. By modulating the degree of oxygen inhibition during synthesis, we achieved previously unattainable particle sizes. Brownian diffusion of colloidal discs in bulk suggests the out-of-plane dimension can be as small as 0.8 mm, which agrees with confocal microscopy measurements. We measured the hindered diffusion of microdiscs near a solid surface and compared our results to theoretical predictions. These colloidal particles can also flow through physiological microvascular networks formed by endothelial cells undergoing vasculogensis under minimal hydrostatic pressure ($5 mm H 2 O). This versatile platform creates future opportunities for on-chip parametric studies of particle geometry effects on particle passage properties, distribution and cellular interactions.

Flexible Octopus‐Shaped Hydrogel Particles for Specific Cell Capture

“…As another negative control, we incubated plain PEGDA‐AAc particles (before functionalization) with the cells under identical conditions and found no capture of either cell type. This confirms the bio‐inert nature of PEGDA particles, and shows that the copolymerized AAc does not lead to any nonspecific interactions. Other groups have also shown PEG‐based and PEG‐functionalized hydrogels to be suitable materials for antibody‐based cell capture, and have demonstrated triggered cell release by breaking photolabile or physical crosslinks within the gel .…”

Microfluidic Synthesis of pH‐Sensitive Multicompartmental Microparticles for Multimodulated Drug Release

“…The pH‐responsive, multicompartmental particles synthesized via SFL have high potential to serve as a codelivery vehicle for synergistic combination therapy, allowing controlled release of multiple drugs into target disease regions, such as sites of cancer and inflammation. Development of nanosized, multicompartmental particles that can allow for passive tumor targeting via the enhanced permeability and retention (EPR) effect when systemically administered is currently under investigation by utilizing oxygen‐controlled flow lithography . Further chemical modification is also underway to fabricate multicompartmental K‐DAA particles for controlled release of more than two drugs.…”

Biodegradable Microparticles for Simultaneous Detection of Counterfeit and Deteriorated Edible Products

“…Microparticle Synthesis : The details of the SFL setup were described previously . Compressed air was used to generate a pressure difference to induce flow in the channel.…”