Nanotopographic Influence on the In Vitro Behavior of Induced Pluripotent Stem Cells

Great Expectations: Induced pluripotent stem cell technologies in neurodevelopmental impairments

Somatic cells such as skin fibroblasts, umbilical cord blood, peripheral blood, urinary epithelial cells, etc., are transformed into induced pluripotent stem cells (iPSCs) by reprogramming technology, a milestone in the stem-cell research field. IPSCs are similar to embryonic stem cells (ESCs), exhibiting the potential to differentiate into various somatic cells. Still, the former avoid problems of immune rejection and medical ethics in the study of ESCs and clinical trials. Neurodevelopmental disorders are chronic developmental brain dysfunctions that affect cognition, exercise, social adaptability, behavior, etc. Due to various inherited or acquired causes, they seriously affect the physical and psychological health of infants and children. These include generalized stunting / mental disability (GDD/ID), Epilepsy, autism spectrum disease (ASD), and attention deficit hyperactivity disorder (ADHD). Most neurodevelopmental disorders are challenging to cure. Establishing a neurodevelopmental disorder system model is essential for researching and treating neurodevelopmental disorders. At this stage, the scarcity of samples is a bigger problem for studying neurological diseases based on the donor, ethics, etc. Some iPSCs are reprogrammed from somatic cells that carry disease-causing mutations. They differentiate into nerve cells by induction, which has the original characteristics of diseases. Disease-specific iPSCs are used to study the mechanism and pathogenesis of neurodevelopmental disorders. The process provided samples and the impetus for developing drugs and developing treatment plans for neurodevelopmental disorders. Here, this article mainly introduced the development of iPSCs, the currently established iPSCs disease models, and artificial organoids related to neurodevelopmental impairments. This technology will promote our understanding of neurodevelopmental impairments and bring great expectations to children with neurological disorders.

Differentiation of induced pluripotent stem cells to hepatocyte-like cells on cellulose nanofibril substrate

Differentiation of hepatocyte-like cells (HLCs) from human induced pluripotent stem cells (iPSCs) in vitro has great potential in regenerative medicine. Current protocol uses matrigel of animal origin as a substrate for the differentiation of iPSCs to HLCs. Use of an appropriate non-xenogenic substrate is very important for potential future clinical applications. Towards this goal, we used Cellulose Nanofibril (CNF) gel, a natural, non-toxic, biocompatible and biodegradable polymer in humans as a thin film substrate for the differentiation of iPSCs to HLCs. Here we demonstrated that CNF as a substrate film can efficiently differentiate human iPSCs to HLCs. We investigated the expression profile of the endoderm markers (SOX17 and CXCR4), hepatoblast markers (EpCAM and AFP) and mature hepatocyte marker (ASGPR1) by flow cytometry during the differentiation of iPSCs to HLCs on both CNF and matrigel substrates. We also tested the HLCs generated from both the substrates for the expression of hepatic markers such as A1AT, HNF4A, CYP450 isotypes by Real Time-PCR and its mature hepatocyte functions (lipid accumulation and albumin expression). Our results showed that the differentiated HLCs from both the substrates are comparable and expressed stage specific hepatocyte markers as well as functional maturity. We have demonstrated that CNF, a natural biomaterial, may be used in tissue engineering applications as a potential substrate for the differentiation of iPSCs to HLCs.

Emerging Methods for Enhancing Pluripotent Stem Cell Expansion

Pluripotent stem cells (PSCs) have great potential to revolutionize the fields of tissue engineering and regenerative medicine as well as stem cell therapeutics. However, the end goal of using PSCs for therapeutic use remains distant due to limitations in current PSC production. Conventional methods for PSC expansion have limited potential to be scaled up to produce the number of cells required for the end-goal of therapeutic use due to xenogenic components, high cost or low efficiency. In this mini review, we explore novel methods and emerging technologies of improving PSC expansion: the use of the two-dimensional mechanobiological strategies of topography and stiffness and the use of three-dimensional (3D) expansion methods including encapsulation, microcarrier-based culture, and suspension culture. Additionally, we discuss the limitations of conventional PSC expansion methods as well as the challenges in implementing non-conventional methods.

Current strategies and opportunities to manufacture cells for modeling human lungs

Chronic lung diseases remain major healthcare burdens, for which the only curative treatment is lung transplantation. In vitro human models are promising platforms for identifying and testing novel compounds to potentially decrease this burden. Directed differentiation of pluripotent stem cells is an important strategy to generate lung cells to create such models. Current lung directed differentiation protocols are limited as they do not 1) recapitulate the diversity of respiratory epithelium, 2) generate consistent or sufficient cell numbers for drug discovery platforms, and 3) establish the histologic tissue-level organization critical for modeling lung function. In this review, we describe how lung development has formed the basis for directed differentiation protocols, and discuss the utility of available protocols for lung epithelial cell generation and drug development. We further highlight tissue engineering strategies for manipulating biophysical signals during directed differentiation such that future protocols can recapitulate both chemical and physical cues present during lung development.

Shaping Cell Fate: Influence of Topographical Substratum Properties on Embryonic Stem Cells

Development of multicellular organisms is a highly orchestrated process, with cells responding to factors and features present in the extracellular milieu. Changes in the surrounding environment help decide the fate of cells at various stages of development. This review highlights recent research that details the effects of mechanical properties of the surrounding environment and extracellular matrix and the underlying molecular mechanisms that regulate the behavior of embryonic stem cells (ESCs). In this study, we review the role of mechanical properties during embryogenesis and discuss the effect of engineered microtopographies on ESC pluripotency.