Microscale Interfacial Polymerization on a Chip.

Marco Rocca,Marie Salva,Emmanuel Delamarche,Maxime Dufresne,Christof M Niemeyer

doi:10.1002/anie.202110974

Abstract

Forming hydrogels with precise geometries is challenging and mostly done using photopolymerization, which involves toxic chemicals, rinsing steps, solvents, and bulky optical equipment. Here, we introduce a new method for in situ formation of hydrogels with a well‐defined geometry in a sealed microfluidic chip by interfacial polymerization. The geometry of the hydrogel is programmed by microfluidic design using capillary pinning structures and bringing into contact solutions containing hydrogel precursors from vicinal channels. The characteristics of the hydrogel (mesh size, molecular weight cut‐off) can be readily adjusted. This method is compatible with capillary‐driven microfluidics, fast, uses small volumes of reagents and samples, and does not require specific laboratory equipment. Our approach creates opportunities for filtration, hydrogel functionalization, and hydrogel‐based assays, as exemplified by a rapid, compact competitive immunoassay that does not require a rinsing step.

Highlights

Forming hydrogels with precise geometries is challenging and mostly done using photopolymerization, which involves toxic chemicals, rinsing steps, solvents, and bulky optical equipment
We report here on the use of sealed capillary-driven microfluidic chips for the in situ production of biocompatible hydrogels by taking advantage of interfacial polymerization.[23,24,25]
Using polyethylene-glycol (PEG)-based hydrogels as model systems, we demonstrate that our platform enables rapid prototyping of materials with respect to their polymerization properties and solute diffusion profiles

Summary

Introduction

Forming hydrogels with precise geometries is challenging and mostly done using photopolymerization, which involves toxic chemicals, rinsing steps, solvents, and bulky optical equipment. We report here on the use of sealed capillary-driven microfluidic chips for the in situ production of biocompatible hydrogels by taking advantage of interfacial polymerization.[23,24,25] Using polyethylene-glycol (PEG)-based hydrogels as model systems, we demonstrate that our platform enables rapid prototyping of materials with respect to their polymerization properties and solute diffusion profiles. PEG hydrogels were chosen because of their adjustable chemical composition and mechanical properties, protein biocompatibility and ease of chemical functionalization.[29] In our method, two precursors in aqueous solutions, 4-armed PEG maleimide (4PM) and PEG-dithiol (PDT) (Figure 1 b), are sequentially introduced into the central and donor channel, respectively, of the microfluidic chip and the capillary pinning structures define the interface between the two solutions (Figure 1 c).

Results

Conclusion