Micropatterning of Hydrogels on Locally Hydrophilized Regions on PDMS by Stepwise Solution Dipping and in Situ Gelation

Abstract

This study presents a simple but highly versatile method of fabricating picoliter-volume hydrogel patterns on poly(dimethylsiloxane) (PDMS) substrates. Hydrophilic regions were prepared on hydrophobic PDMS plates by trapping and melting functional polymer particles and performing subsequent reactions with partially oxidized dextran. Small aliquots of a gelation solution were selectively trapped on the hydrophilic areas by a simple dipping process that was utilized to make thin hydrogel patterns by the in situ gelation of a sol solution. Using this process, we successfully formed calcium alginate, collagen I, and chitosan hydrogels with a thickness of several micrometers and shapes that followed the hydrophilized regions. In addition, alginate and collagen gel patterns were used to capture cells with different adhesion properties selectively on or off the hydrogel structures. The presented strategy could be applicable to the preparation of a variety of hydrogels for the development of functional biosensors, bioreactors, and cell cultivation platforms.

Alginate-Based Biomaterials for Regenerative Medicine Applications

“…Recently, the use of a tissue engineering approach for developing a 3D high throughput screening assay for drug screening and diagnostic devices has been of great interest [142,143,144,145]. An alginate hydrogel has been utilized as a 3D platform for microarray systems as well as surface micro-patternings.…”

Importance of Alginate Bioink for 3D Bioprinting in Tissue Engineering and Regenerative Medicine

“…Tissueengineered cartilage requirement is immense and has a huge clinical importance. The main causes of disability of the articular cartilage are degenerative and traumatic lesions [29]. Nearly 100 million Chinese people suffer from osteoarthritis.…”

Microfluidic production of single micrometer-sized hydrogel beads utilizing droplet dissolution in a polar solvent

“…Alginate is a biocompatible polymer obtained from seaweed, which rapidly gels in the presence of multivalent cations such as Ca 2þ and Ba 2þ . Because of the mild gelation conditions required, alginate hydrogels have been used for a variety of applications, including biological immobilization for bio-production, 39 patterned cell culture, 40 tissue engineering, 41,42 and cell transplantation therapies. 43 In this study, we introduced an aqueous solution of the gelation agent (1M CaCl 2 ) into the microfluidic device (with a dissolution channel length of 70 mm) at the second confluence point, by which time the droplet shrinkage was almost complete.…”