Auxiliary Liver Organ Formation by Implantation of Spleen-Encapsulated Hepatocytes

Core-Shell Nanofibrous Scaffold Based on Polycaprolactone-Silk Fibroin Emulsion Electrospinning for Tissue Engineering Applications

The vast domain of regenerative medicine comprises complex interactions between specific cells' extracellular matrix (ECM) towards intracellular matrix formation, its secretion, and modulation of tissue as a whole. In this domain, engineering scaffold utilizing biomaterials along with cells towards formation of living tissues is of immense importance especially for bridging the existing gap of late; nanostructures are offering promising capability of mechano-biological response needed for tissue regeneration. Materials are selected for scaffold fabrication by considering both the mechanical integrity and bioactivity cues they offer. Herein, polycaprolactone (PCL) (biodegradable polyester) and 'nature's wonder' biopolymer silk fibroin (SF) are explored in judicious combinations of emulsion electrospinning rather than conventional electrospinning of polymer blends. The water in oil (W/O) emulsions' stability is found to be dependent upon the concentration of SF (aqueous phase) dispersed in the PCL solution (organic continuous phase). The spinnability of the emulsions is more dependent upon the viscosity of the solution, dominated by the molecular weight of PCL and its concentration than the conductivity. The nanofibers exhibited distinct core-shell structure with better cytocompatibility and cellular growth with the incorporation of the silk fibroin biopolymer.

Novel integrative methodology for engineering large liver tissue equivalents based on three-dimensional scaffold fabrication and cellular aggregate assembly

A novel engineering methodology for organizing a large liver tissue equivalent was established by intergrating both 'top down' and 'bottom up' approaches. A three-dimensional (3D) scaffold was engineered comprising 43 culture chambers (volume: 11.63 cm(3)) assembled in a symmetrical pattern on 3 layers, a design which enables further scaling up of the device to a clinically significant size (volume: 500 cm(3)). In addition, an inter-connected flow channel network was designed and proved to homogenously deliver culture medium to each chamber with the same pressure drop. After fabrication using nylon-12 and a selective laser sintering process, co-cultured cellular aggregates of human hepatoma Hep G2 and TMNK-1 cells were loosely packed into the culture chambers with biodegradable poly-L-lactic acid fibre pieces for 9 days of perfusion culture. The device enabled increased hepatic function and well-maintained cell viability, demonstrating the importance of an independent medium flow supply for cell growth and function provided by the current 3D scaffold. This integrative methodology from the macro- to the micro-scale provides an efficient way of arranging engineered liver tissue with improved mass transfer, making it possible to further scale up to a construct with clinically relevant size while maintaining high per-volume-based physiological function in the near future.

The Scottish Liver Transplant Unit: current and future perspectives

The Scottish Liver Transplant Unit (SLTU) opened in 1992 and has now performed over 900 liver transplants. During this time there have been major changes in both organ donation and transplantation. Currently liver transplantation is restricted by limited organ supply. Scotland has one of the lowest rates of organ donation in Europe and one of the most rapidly increasing rates of cirrhosis. The consequent waiting list mortality has driven innovations including increasing use of marginal grafts, organs donated after cardiac death, split-liver transplants and the development of living-donor liver transplantation. To maintain liver transplantation, there is an urgent need to increase organ donation rates and to find novel treatments which optimize outcomes from marginal grafts. This review addresses the surgical aspects of liver transplantation and how these have evolved over the two past decades. Major changes are currently underway in organ donation organization, and there is continuing refinement of organ treatment and storage. A number of measures to maintain and improve organ preservation and function are currently being evaluated in clinical trials, and cell therapy holds significant potential for the future. Scotland has a rising need for liver transplantation and the SLTU continues to provide high-quality care and to be at the forefront of the latest advances in organ transplantation.

Transplantation of a fetal liver cell-loaded hyaluronic acid sponge onto the mesentery recovers a Wilson's disease model rat

An auxiliary liver represents a promising alternative for liver transplantation. The use of a large amount of mature hepatocytes, however, despite their high function, is limited in a clinical setting. Here, we propose a novel transplantation system that dramatically improved a diseased animal by incorporating fetal liver cells (FLCs) as a cell source, the mesentery as a transplantation site and a hyaluronic acid (HA) sponge as a cell scaffold. We transplanted wild-type Long Evans Agouti rat FLCs embedded in HA sponges onto the mesentery of Long Evans Cinnamon (LEC) rats, an animal model for Wilson's disease. The FLC-loaded HA sponges successfully grafted and consequently prevented jaundice. Accordingly, the treated animals showed a significant reduction in blood copper concentration, which consequently led to significant decreases in serum total bilirubin and direct bilirubin, and to a significant increase in albumin productivity. Furthermore, haematoxylin and eosin staining of the host livers demonstrated that fibrosis at the periportal area was moderated in the treated animals. In conclusion, we transplanted FLC-loaded HA sponges onto the mesenteric blood vessels, leading to thick, liver-like tissue possessing blood vessels, and the liver tissue engineered thus exhibited a remarkable therapeutic effect on the copper metabolism deficiency of LEC rats.

Adhesion behavior of human bone marrow stromal cells on differentially wettable polymer surfaces

An appropriate cellular response to implanted surfaces is essential for tissue regeneration and integration. In this study, we investigated how human bone marrow stromal cells (hBMSCs) respond to scaffold substrates. We prepared wettable polymer surfaces by exposing polymer sheets to radio frequency plasma discharge, which gradually oxidizes the polymer surface, increasing the roughness and greatly reducing the hydrophobicity. We found that hBMSCs adhered better to highly hydrophilic and rough surfaces than to hydrophobic and smooth surfaces. In addition, the cells flattened extensively on hydrophilic surfaces. Further, c-fos gene expression increased in parallel with the degree of hydrophilicity, whereas the expression of the c-myc gene was higher on hydrophobic than on hydrophilic surfaces. Finally, p53 gene expression was higher on more hydrophobic or hydrophilic surfaces than on moderately hydrophobic or hydrophilic surfaces. These results indicate that the biological signals induced by cell adhesion depend on the wettability of the surface to which the cells attach.