Recent advances in nonbiofouling PDMS surface modification strategies applicable to microfluidic technology

Abstract

In the last decade microfabrication processes including rapid prototyping techniques have advanced rapidly and achieved a fairly mature stage. These advances have encouraged and enabled the use of microfluidic devices by a wider range of users with applications in biological separations and cell and organoid cultures. Accordingly, a significant current challenge in the field is controlling biomolecular interactions at interfaces and the development of novel biomaterials to satisfy the unique needs of the biomedical applications. Poly(dimethylsiloxane) (PDMS) is one of the most widely used materials in the fabrication of microfluidic devices. The popularity of this material is the result of its low cost, simple fabrication allowing rapid prototyping, high optical transparency, and gas permeability. However, a major drawback of PDMS is its hydrophobicity and fast hydrophobic recovery after surface hydrophilization. This results in significant nonspecific adsorption of proteins as well as small hydrophobic molecules such as therapeutic drugs limiting the utility of PDMS in biomedical microfluidic circuitry. Accordingly, here, we focus on recent advances in surface molecular treatments to prevent fouling of PDMS surfaces towards improving its utility and expanding its use cases in biomedical applications.

Multiplexed blood–brain barrier organ-on-chip

“…58 PDMS mediated absorption can reportedly be minimized in future by performing a surface modification as was shown before. 59…”

Vascularized Liver Organoids Generated Using Induced Hepatic Tissue and Dynamic Liver‐Specific Microenvironment as a Drug Testing Platform

“…In our study, we did not determine the actual concentrations of drug (APAP) used for testing in microfluidic devices, but the data showing drug dose‐dependent cellular responses (Figure f,g) indicate that drug absorption to PDMS may not be significant to influence the results in our drug testing. However, several strategies to avoid drug absorption issue of PDMS (e.g., surface modification, device fabrication with thermoplastics) could be considered to further improve the performance of our microfluidic systems for organoid experiments …”

Comparison of Escherichia coli surface attachment methods for single-cell microscopy

“…APTES is a common choice for salinisation of microfluidic channels 47 , and has also been employed as an attachment agent for the AFM imaging 19 . We coat coverslips by incubating them in a 2% solution of APTES for 2 h followed by extensive washing with water and acetone as described in Materials and Methods.…”