3D Bioprintable GelMA Ultrasound Responsive Scaffolds for Precise Micropatterning and Spatiotemporal Drug Release

Abstract

In recent years, there has been increasing interest in hydrogels as a platform for patient-specific treatments such as drug release. Possessing a variety of highly tunable mechanical and biocompatible properties, hydrogels can be synthesized using natural or synthetic materials to recapitulate the native biological environment. Drug release and cell encapsulation, among others are just some of the qualities that can be imparted into hydrogels. We have developed a composite hydrogel, termed an acoustically responsive scaffold (ARS), that enables spatiotemporally controlled drug delivery using focused ultrasound. An ARS consists of a phase-shift emulsion (PSE) embedded within a hydrogel matrix. Upon exposure to ultrasound, the emulsion undergoes acoustic droplet vaporization (ADV), thereby releasing payloads initially encapsulated within the emulsion. Similar to conventional hydrogels, ARSs have previously been polymerized using bulk polymerization techniques. There are inherent limitations with this approach. First, the form factor of the ARS is dictated by the shape of the container that holds the solution during crosslinking. Second, the ability to generate complex patterns of emulsions within an ARS is very limited.