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 hepatoma cell line 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 6 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 represent a proof of concept of an interesting new cell culture technology that should be further investigated to engineer healthy and cirrhotic liver models.

An Engineered Protein-Based Building Block (Albumin Methacryloyl) for Fabrication of a 3D In Vitro Cryogel Model

“…Recently, Lilandra Boulais and co-workers fabricated an engineered alginate-based cryogel-integrated biochip for dynamic hepatoma cell line culture. The pore size and mechanical properties of alginate-based cryogels were similar to those of BSAMA-based cryogels, but the swelling ratio of albumin-based cryogels (B5) was much larger than that of the alginate-based cryogels [ 32 ]. The cryostructuring via ice crystal formation in the frozen phase could impact the cross-linking/polymerization procedure in the unfrozen liquid microphase, leading to different porous structures [ 39 ].…”

“…In addition, a swelling ratio and porosity of BSAMA cryogels were measured via the volume of PBS (pH 7.4) absorbed by BSAMA cryogel scaffolds [ 32 , 72 ]. …”

“…Cryogel technologies are expected to address challenges in tissue engineering and other emerging bioengineering disciplines. Recently, Boulais et al has reported an alginate-based cryogel-integrated biochip for liver tissue engineering and drug screening in which cell-laden cryogels with 1.5 kPa (as a healthy liver model) and 29 kPa (as a cirrhotic liver model) were examined for albumin synthesis and glucose consumption for up to 6 days [ 32 ]. However, the cryogel chip supported only short-term culture and was not tested for predictive toxicology and drug screening.…”

Development of Liver-on-Chip Integrating a Hydroscaffold Mimicking the Liver’s Extracellular Matrix

“…Recently, we integrated an alginate cryogel into our biochip to promote 3D cell organization. The cells colonize the entire surface of the collagen-coated cryogel, forming a thick (200 µm) tissue-like 3D structure from the bottom to the top of the biochip [ 33 ]. In the present study, we propose a new liver-on-chip model integrating a hydroscaffold allowing cells to organize into a complex 3D spheroid architecture.…”

Poly(lactic acid)/Zinc/Alginate Complex Material: Preparation and Antimicrobial Properties

“…Due to the low affinity of metallic cations to carboxylic ester bonds [ 57 ], PLA weakly binds zinc ions, and its antibacterial PLA-Zn (2+) composites require an interface covering layer with high affinity to copper. Such requirements fulfill alginates, biodegradable biopolymers [ 58 , 59 , 60 , 61 , 62 , 63 ] applied as a basis for drug delivery [ 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ], tissue engineering [ 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 ], and wound dressings [ 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 ].…”