Optimized performance of the integrated hepatic cell-loaded cryogel-based bioreactor with intermittent perfusion of acute liver failure plasma

Decellularized liver matrix-modified chitosan fibrous scaffold as a substrate for C3A hepatocyte culture

A bioreactor filled with functional hepatocytes is a crucial portion of the bio-artificial liver device. However, it is a difficult task to maintain sufficient cell quantity and active hepatocellular function. In this work, we developed a promising scaffold for hepatocyte culture by coating porcine liver extracellular matrix (ECM) on chitosan (CTS) fabrics. Porcine Liver was decellularized using 1% Triton X-100. Solubilized liver ECM was immobilized on CTS fibers surface through cross linking of ECM and CTS with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-Hydroxysuccinimide (NHS). Then the scaffold was characterized by Fourier transformed infrared spectroscopy in attenuated total reflection mode (ATR-FTIR), X-photoelectron spectroscopy (XPS) and water contact angle measurement. The efficacy of modified scaffolds to maintain C3A hepatocytes adhesion, proliferation, bioactivity and functionality in vitro was detected. FTIR spectra and XPS demonstrated the presence of ECM coating on CTS fabric surface. Covalently attached coating significantly improved the binding efficiency between ECM and CTS fabrics, in comparison to the coating by physical absorption. Furthermore, C3A hepatocytes cultured on coated scaffolds showed enhanced cell bioactivity and liver-specific function, such as albumin secretion and urea synthesis, compared with those cultured on untreated scaffolds(p < 0.05). As a promising hepatocyte culture carrier, the ECM coated CTS fabrics could be applied in the biological artificial liver reactor.

Bilirubin detoxification using different phytomaterials: characterization and in vitro studies

BACKGROUND

Activated carbon (AC) is a common adsorbent that is used in both artificial and bioartificial liver devices.

METHODS

Three natural materials - date pits of Phoenix dactylifera (fruit), Simmondsia chinensis (jojoba) seeds, and Scenedesmus spp. (microalgae) - were used in the present investigation as precursors for the synthesis of AC using physical activation. The chemical structures and morphology of AC were analyzed. Then, AC's bilirubin adsorption capacity and its cytotoxicity on normal liver (THLE2) and liver cancer (HepG2) cells were characterized.

RESULTS

Compared with the other raw materials examined, date-pit AC was highly selective and showed the most effective capacity of bilirubin adsorption, as judged by isotherm-modeling analysis. MTT in vitro analysis indicated that date-pit AC had the least effect on the viability of both THLE2 and HepG2 cells compared to jojoba seeds and microalgae. All three biomaterials under investigation were used, along with collagen and Matrigel, to grow cells in 3D culture. Fluorescent microscopy confirmed date-pit AC as the best to preserve liver cell integrity.

CONCLUSION

The findings of this study introduce date-pit-based AC as a novel alternative biomaterial for the removal of protein-bound toxins in bioartificial liver devices.

Decellularized Liver Matrix-Modified Cryogel Scaffolds as Potential Hepatocyte Carriers in Bioartificial Liver Support Systems and Implantable Liver Constructs

Recent progress in the use of decellularized organ scaffolds as regenerative matrices for tissue engineering holds great promise in addressing the issue of donor organ shortage. Decellularization preserves the mechanical integrity, composition, and microvasculature critical for zonation of hepatocytes in the liver. Earlier studies have reported the possibility of repopulating decellularized matrices with hepatic cell lines or stem cells to improve liver regeneration. In this work, we study the versatility of the decellularized liver matrix as a substrate coating of three-dimensional cryogel scaffolds. The coated cryogels were analyzed for their ability to maintain hepatic cell growth and functionality in vitro, which was found to be significantly better than the uncoated cryogel scaffolds. The decellularized liver matrix-coated cryogel scaffolds were evaluated for their potential application as a cell-loaded bioreactor for bioartificial liver support and as an implantable liver construct. Extracorporeal connection of the coated cryogel bioreactor to a liver failure model showed improvement in liver function parameters. Additionally, offline clinical evaluation of the bioreactor using patient-derived liver failure plasma showed its efficacy in improving liver failure conditions by approximately 30-60%. Furthermore, implantation of the decellularized matrix-coated cryogel showed complete integration with the native tissue as confirmed by hematoxylin and eosin staining of tissue sections. HepG2 cells and primary human hepatocytes seeded in the coated cryogel scaffolds implanted in the liver failure model maintained functionality in terms of albumin synthesis and cytochrome P450 activity post 2 weeks of implantation. In addition, a 20-60% improvement in liver function parameters was observed post implantation. These results, put together, suggest a possibility of using the decellularized matrix-coated cryogel scaffolds for liver tissue engineering applications.