Survival, Proliferation, and Functions of Porcine Hepatocytes Encapsulated in Coated Alginate Beads: A Step Toward a Reliable Bioartificial Liver1

Abstract

Orthotopic liver transplantation is the most effective treatment for fulminant hepatic failure. As an alternative treatment, an efficient extracorporeal bioartificial liver should contain a large yield of functional hepatocytes with an immunoprotective barrier, for providing temporary adequate metabolic support to allow spontaneous liver regeneration or for acting as a bridge toward transplantation. Survival, proliferation, and functions of porcine hepatocytes were evaluated in primary cultures and after embedding in alginate beads, which were subsequently coated with a membrane made by a transacylation reaction between propylene glycol alginate and human serum albumin. Disruption of total pig livers by collagenase perfusion/recirculation allowed the obtention of up to 10(11) hepatocytes with a viability greater than 95%. Hepatocytes in conventional cultures or embedded in coated alginate beads survived for about 10 days, secreted proteins, particularly albumin, and maintained several phase I and II enzymatic activities, namely ethoxyresorufin-O-deethylase, oxidation of nifedipine to pyridine, phenacetin deethylation to paracetamol, glucuroconjugation of paracetamol, and N-acetylation of procainamide. Typical features of mitosis and [3H]thymidine incorporation indicated that porcine hepatocytes proliferated in both conventional cultures and alginate beads. The efficacy of the membrane surrounding alginate beads for protecting cells from immunoglobulins was tested by embedding HLA-typed human lymphocytes, which were subsequently incubated with specific anti-HLA immunoglobulin G and complement. These data show that large yields of porcine hepatocytes that are embedded in coated alginate beads remain functional and are isolated from large molecular weight molecules, such as immunoglobulins. This system represents a promising tool for the design of an extracorporeal bioartificial liver, containing xenogeneic hepatocytes, to treat acute liver disease in humans.

Enhancement of posterolateral lumbar spine fusion using low‐dose rhBMP‐2 and cultured marrow stromal cells

“…Alginate has been employed to microencapsulate and entrap antibiotics and cells. [19][20][21][22] Recently, Ueng et al successfully developed a biodegradable alginate carrier system for antibiotics and MSCs in the rabbit model. 10 This study successfully transferred the MSCs to the host via an alginate carrier system, and the histology results indicated no inflammatory reaction.…”

The Effectiveness of a Novel Cartridge-Based Bioreactor Design in Supporting Liver Cells

“…2,3 Unfortunately, this configuration has the inherent physical limitations of constrained total mass diffusion distances, limited cellular mass capacity, and nonuniform cell distributions. While the designs of encapsulation and suspension chambers can provide uniform microenvironments and ease of scaleup, [4][5][6] they can also offer poor cell stability (true for suspensions) and nutrient transport barriers (i.e., encapsulation systems). Moreover, the cells in such systems are typically exposed to higher shear forces.…”

Effect of Oxygen Concentration on Viability and Metabolism in a Fluidized-Bed Bioartificial Liver Using 31P and 13C NMR Spectroscopy

“…Langendorf 14 initially used a 95% oxygen mixture in his perfused heart studies, and this has remained the standard for tissue engineering for the majority of perfused membrane-type BALs, while 3D encapsulationtype BALs 8,10,26,27,40 and organoid constructs 41,42 have varied. Hepatocytes are highly aerobic, requiring high amounts of oxygen relative to other tissues.…”