Mesenchymal stem cell (MSC)-based liver tissue engineering on nanofibrous scaffold holds great promise for cell-based therapy in liver injuries and end-stage liver failure treatments. We investigated the hepatic trans-differentiation potential of human MSCs on a biocomposite poly(L-lactic acid)-co-poly (ε-caprolactone)/collagen (PLACL/collagen) nanofibrous scaffold. The nanofibrous scaffolds comprised of PLACL, collagen and a PLACL/collagen blend (2 : 1) were fabricated by electrospinning and also evaluated for fiber morphology, surface wettability, functional groups, porosity and tensile properties. Hepatic trans-differentiation of human bone marrow-derived MSCs (hMSCs) was carried out on these scaffolds over a period of 28 days using sequential induction with hepatogenic growth factors. Hepatogenesis was confirmed by scanning electron microscopy (SEM), cell phenotype tracking dye expression, quantitative expression of hepatic genes, immunofluorescence staining of hepatocyte-specific markers and albumin release. The results proved that the porous PLACL/collagen nanofibrous scaffold supported enhanced hMSC proliferation and hepatic trans-differentiation compared to individual PLACL and collagen scaffolds as well as a monolayer culture on tissue culture plate (TCP). Interestingly, hMSC-derived hepatocyte-like cells on PLACL/collagen nanofibrous scaffolds could aggregate to form functional ‘hepatospheres’ similar to normal hepatic spheroids. The present study concludes that PLACL/collagen nanofibrous scaffolds are potentially biomimetic and upon sequential induction with hepatogenic growth factors/cytokines, it augments trans-differentiation of hMSCs towards functional hepatosphere formation. Such bioengineered nanofibrous scaffold hepatic construct provides a promising approach for cellular therapy of damaged livers in end-stage liver failure treatments.

Myocardium Infarction (MI) is one of the foremost cardiovascular diseases (CVDs) causing death worldwide, and its case numbers are expected to continuously increase in the coming years. Pharmacological interventions have not been at the forefront in ameliorating MI-related morbidity and mortality. Stem cell-based tissue engineering approaches have been extensively explored for their regenerative potential in the infarcted myocardium. Recent studies on microfluidic devices employing stem cells under laboratory set-up have revealed meticulous events pertaining to the pathophysiology of MI occurring at the infarcted site. This discovery also underpins the appropriate conditions in the niche for differentiating stem cells into mature cardiomyocyte-like cells and leads to engineering of the scaffold via mimicking of native cardiac physiological conditions. However, the mode of stem cell-loaded engineered scaffolds delivered to the site of infarction is still a challenging mission, and yet to be translated to the clinical setting. In this review, we have elucidated the various strategies developed using a hydrogel-based system both as encapsulated stem cells and as biocompatible patches loaded with cells and applied at the site of infarction.

Hepatocyte‐like cells (HLCs) generated in vitro from human pluripotent stem cells (hPSCs) provide an invaluable resource for basic research, regenerative medicine, drug screening, toxicology, and modeling of liver disease and development. This unit describes a small‐molecule‐driven protocol for in vitro differentiation of hPSCs into HLCs without the use of growth factors. hPSCs are coaxed through a developmentally relevant route via the primitive streak to definitive endoderm (DE) using the small molecule CHIR99021 (a Wnt agonist), replacing the conventional growth factors Wnt3A and activin A. The small‐molecule‐derived DE is then differentiated to hepatoblast‐like cells in the presence of dimethyl sulfoxide. The resulting hepatoblasts are then differentiated to HLCs with N‐hexanoic‐Tyr, Ile‐6 aminohexanoic amide (Dihexa, a hepatocyte growth factor agonist) and dexamethasone. The protocol provides an efficient and reproducible procedure for differentiation of hPSCs into HLCs utilizing small molecules. © 2016 by John Wiley & Sons, Inc.

A challenge facing the human pluripotent stem cell (hPSC) field is the variability observed in differentiation potential of hPSCs. Variability can lead to time consuming and costly optimisation to yield the cell type of interest. This is especially relevant for the differentiation of hPSCs towards the endodermal lineages. Endodermal cells have the potential to yield promising new knowledge and therapies for diseases affecting multiple organ systems, including lung, thymus, intestine, pancreas and liver, as well as applications in regenerative medicine and toxicology. Providing a means to rapidly, cheaply and efficiently assess the differentiation potential of multiple hPSCs is of great interest. To this end, we have developed a rapid small molecule based screen to assess the endodermal potential (EP) of hPSCs, based solely on definitive endoderm (DE) morphology. This drastically reduces the cost and time to identify lines suitable for use in deriving endodermal lineages. We demonstrate the efficacy of this screen using 10 different hPSCs, including 4 human embryonic stem cell lines (hESCs) and 6 human induced pluripotent stem cell lines (hiPSCs). The screen clearly revealed lines amenable to endodermal differentiation, and only lines that passed our morphological assessment were capable of further differentiation to hepatocyte like cells (HLCs).