Cryogel-Integrated Biochip for Liver Tissue Engineering

Abstract

Microfluidic systems and polymer hydrogels have been widely developed for tissue engineering. Yet only a few tools combining both approaches, especially for in vitro liver models, are being explored. In this study, an alginate-based cryogel-integrated biochip was engineered for dynamic hepatocyte cell culture in three dimensions (3D). The alginate cryogel was covalently cross-linked in the biochip at subzero temperatures (T < 0 °C) to create a scaffold with high mechanical stability and an interconnected macroporous network. By varying the alginate concentration and the cross-linker ratio, the Young’s modulus of the cryogel can be fine-tuned between 1.5 and 29 kPa, corresponding to the range of stiffness of the different physiological states of the liver. We demonstrated that HepG2/C3A cells can be cultured and maintained viable under dynamic conditions in this device up to 7 days. Albumin synthesis and glucose consumption increased over the cell culture days. Moreover, a 3D cell structure was observed across the entire height of the biochip, which was preserved following alginate lyase treatment to remove the cryogel-based scaffold. In summary, these results suggest a promising cell culture technology with great potential for pharmaceutical industries to engineer healthy and cirrhotic liver models for middle-throughput predictive toxicology and drug screening.