Hepatocyte behavior within three-dimensional porous alginate scaffolds

Area of Science:

• Biomaterials Science
• Hepatology
• Tissue Engineering

Background:

• Implanted hepatocyte performance can be improved by pre-implantation aggregation and re-expression of differentiated functions.
• Novel biomaterials are needed to support hepatocyte function in vitro.

Purpose of the Study:

• To investigate the behavior and function of adult rat hepatocytes cultured within a novel three-dimensional (3-D) alginate scaffold.
• To assess the potential of alginate sponges to facilitate hepatocyte aggregation and enhance differentiated function.

Main Methods:

• Freshly isolated rat adult hepatocytes were seeded onto a porous, sponge-like alginate scaffold with pore sizes of 100-150 microm.
• Cell viability, proliferation, aggregation efficiency, spheroid formation, and protein synthesis (fibronectin, laminin, collagen IV) were assessed.
• Albumin and urea secretion rates were measured to evaluate hepatocyte function over a 2-week culture period.

Main Results:

• Hepatocytes seeded efficiently onto the hydrophilic alginate sponges and maintained high viability.
• Over 90% of hepatocytes aggregated into smooth spheroids (average diameter 100 microm) within 4 days, without proliferation.
• Hepatocytes synthesized and deposited fibronectin on spheroids; albumin secretion reached a maximal rate of 60 microg/10(6) cells/day within a week.

Conclusions:

• Alginate sponges provide a conducive 3-D environment that promotes hepatocyte aggregation and enhances functional expression, particularly albumin secretion.
• The non-adherent nature of alginate facilitates efficient cell aggregation.
• These findings suggest that alginate sponges are a promising scaffold for pre-conditioning hepatocytes for implantation.