Hybrid hydrogel confined within 3D-printed polymer matrix for 3D tissue culture

Abstract

In recent decades, there have been rapidly increasing efforts to transform tissue culture from two di-mensional plates to three dimensional (3D) culture systems that better mimic a cell’s in situ environment in tissues. Many techniques have been suggested to represent some aspects of the natural context of cells, em-phasizing extracellular matrix interactions, mass transfer, mechanical properties, cell-to-cell communications, etc. From a materials science perspective, hybrid-type biomaterials are very attractive for fulfilling the multi-ple, complex requirement for in vitro 3D tissue culture. Here we introduce a facile method to fabricate a cell-loaded hydrogel network cross-linked via catechol-ferric ion complexation within mechanically stable, open porous polylactide (PLA) scaffolds for 3D tissue culture. PLA scaffolds with an interconnected 3D structure were fabricated by a fused-deposition-modeling 3D printing technique. Hyaluronic acid (HA) was chemically grafted with catechol groups, which was injected into PLA scaffolds that were pre-treated with ferric chloride to generate a cross-linking network of HA within the macroporous PLA scaffolds. In situ loading of HeLa cancer cells into the hybrid scaffold was successful with a loading efficiency of 89.2 % with no significant cytotoxicity. A 3D-printed culture chamber was fabricated to continuously feed fresh medium to the loaded cells and maintain appropriate humidity, contributing to high cell viability during incubation for 10 days. The prepared hybrid structure serves as an excellent scaffold for prolonged 3D culture of cancer cells, enabling the evaluation of the delivery efficiency and therapeutic efficacy of anti-cancer therapeutics. We expect that our approach to generate a 3D hybridzed structure of a biocompatible hydrogel matrix within mechanically ro-bust, porous solid materials will provide a promising materials platform for prolonged 3D culture of various tissues.