Stem cell culture is typically based on batch-type culture, which is laborious and expensive. Here, we propose a continuous harvest method for stem cells cultured on thermoresponsive nanobrush surfaces. In this method, stem cells are partially detached from the nanobrush surface by reducing the temperature of the culture medium below the critical solution temperature needed for thermoresponse. The detached stem cells are harvested by exchange into fresh culture medium. Following this, the remaining cells are continuously cultured by expansion in fresh culture medium at 37 °C. Thermoresponsive nanobrush surfaces were prepared by coating block copolymers containing polystyrene (for hydrophobic anchoring onto culture dishes) with three types of polymers: (a) polyacrylic acid with cell-binding oligopeptides, (b) thermoresponsive poly-N-isopropylacrylamide, and (c) hydrophilic poly(ethyleneglycol)methacrylate. The optimal coating durations and compositions for these copolymers to facilitate adequate attachment and detachment of human adipose-derived stem cells (hADSCs) and embryonic stem cells (hESCs) were determined. hADSCs and hESCs were continuously harvested for 5 and 3 cycles, respectively, via the partial detachment of cells from thermoresponsive nanobrush surfaces.
One of the goals of medicine is to improve well-being, in line with the principle of beneficence (do no harm). Likewise, scientists claim that the goal of human embryonic stem cell (hESC) research is to find treatments for diseases. In hESC research, stem cells are harvested from a 5-day-old embryo. Surplus embryos from infertility treatments or embryos created for the sole purpose of harvesting stem cells are used in the research, and in the process the embryos get destroyed. The use of human embryos for research purpose raises ethical concern. In this context, the religious leaders play the role to be the moral compass and "reality check" to engage with the public. In Malaysia, the Ministry of Health has outlined the Guidelines for Stem Cell Research and Therapy, reflecting on Islamic principles. Since there has not been much focus on the viewpoints of other faiths in Malaysia, this study attempts to (i) explore the ethical guiding principles deliberated by religious leaders from the Buddhist, Hindu and Catholic traditions and (ii) identify if there is a common ground between the mainstream religious views and principles of medical ethics, in relation to hESC research. Eleven religious leaders representing the Buddhist, Hindu and Catholic traditions were interviewed. Interestingly, though reasoning of religious leaders came from different angles, their underlying concerns revolve around the values of "do no harm" and "intention to save lives". These values are also the key principles in medical ethics. The findings are applied to answer the question as to whether religious and medical guiding principles can co-exist and complement in ethical decision-making, without compromising the values.
In the biomedical field, there is growing interest in using human stem cell-derived neurons as in vitro models for pharmacological and toxicological screening of bioactive compounds extracted from natural products. Lignosus rhinocerus (Tiger Milk Mushroom) is used by indigenous communities in Malaysia as a traditional medicine to treat various diseases. The sclerotium of L. rhinocerus has been reported to have medicinal properties, including various bioactivities such as neuritogenic, anti-inflammatory, and anticancer effects. This study aims to investigate the neuroprotective activities of L. rhinocerus sclerotial extracts. Human embryonic stem cell (hESC)-derived neural lineages exposed to the synthetic glucocorticoid, dexamethasone (DEX), were used as the in vitro models. Excess glucocorticoids have been shown to adversely affect fetal brain development and impair differentiation of neural progenitor cells. Screening of different L. rhinocerus sclerotial extracts and DEX on the hESC-derived neural lineages was conducted using cell viability and neurite outgrowth assays. The neuroprotective effects of L. rhinocerus sclerotial extracts against DEX were further evaluated using apoptosis assays and Western blot analysis. Hot aqueous and methanol extracts of L. rhinocerus sclerotium promoted neurite outgrowth of hESC-derived neural stem cells (NSCs) with negligible cytotoxicity. Treatment with DEX decreased viability of NSCs by inducing apoptosis. Coincubation of L. rhinocerus methanol extract with DEX attenuated the DEX-induced apoptosis and reduction in phospho-Akt (pAkt) level in NSCs. These results suggest the involvement of Akt signaling in the neuroprotection of L. rhinocerus methanol extract against DEX-induced apoptosis in NSCs. Methanol extract of L. rhinocerus sclerotium exhibited potential neuroprotective activities against DEX-induced toxicity in hESC-derived NSCs. This study thus validates the use of human stem cell-derived neural lineages as potential in vitro models for screening of natural products with neuroprotective properties.
The incidence of neurological complications and fatalities associated with Hand, Foot & Mouth disease has increased over recent years, due to emergence of newly-evolved strains of Enterovirus 71 (EV71). In the search for new antiviral therapeutics against EV71, accurate and sensitive in vitro cellular models for preliminary studies of EV71 pathogenesis is an essential prerequisite, before progressing to expensive and time-consuming live animal studies and clinical trials.
Matched MeSH terms: Human Embryonic Stem Cells/cytology*
Human pluripotent stem cells (hPSCs) derived from either blastocyst stage embryos (hESCs) or reprogrammed somatic cells (iPSCs) can provide an abundant source of human neuronal lineages that were previously sourced from human cadavers, abortuses, and discarded surgical waste. In addition to the well-known potential therapeutic application of these cells in regenerative medicine, these are also various promising nontherapeutic applications in toxicological and pharmacological screening of neuroactive compounds, as well as for in vitro modeling of neurodegenerative and neurodevelopmental disorders. Compared to alternative research models based on laboratory animals and immortalized cancer-derived human neural cell lines, neuronal cells differentiated from hPSCs possess the advantages of species specificity together with genetic and physiological normality, which could more closely recapitulate in vivo conditions within the human central nervous system. This review critically examines the various potential nontherapeutic applications of hPSC-derived neuronal lineages and gives a brief overview of differentiation protocols utilized to generate these cells from hESCs and iPSCs.
Recombinant vitronectin-grafted hydrogels were developed by adjusting surface charge of the hydrogels with grafting of poly-l-lysine for optimal culture of human embryonic stem cells (hESCs) under xeno- and feeder-free culture conditions, with elasticity regulated by crosslinking time (10-30 kPa), in contrast to conventional recombinant vitronectin coating dishes, which have a fixed stiff surface (3 GPa). hESCs proliferated on the hydrogels for over 10 passages and differentiated into the cells derived from three germ layers indicating the maintenance of pluripotency. hESCs on the hydrogels differentiated into cardiomyocytes under xeno-free culture conditions with much higher efficiency (80% of cTnT+ cells) than those on conventional recombinant vitronectin or Matrigel-coating dishes just only after 12 days of induction. It is important to have an optimal design of cell culture biomaterials where biological cues (recombinant vitronectin) and physical cues (optimal elasticity) are combined for high differentiation of hESCs into specific cell lineages, such as cardiomyocytes, under xeno-free and feeder-free culture conditions.
The advancement in human stem cell research has promised a viable alternative treatment for a range of ‘incurable diseases’ such as neurological diseases. To date, several studies have documented substantial evidences on the therapeutic properties of stem cells in promoting repair in different diseases including common neurological disorders i.e. ischaemic stroke and spinal cord injury. However, the progress of stem cell research has been surrounded by ethical issues which largely due to the usage of human embryos as one of the sources. These embryonic stem cells which originally derived from human embryo of aborted foetus or already existing human embryonic stem cells (hESCs) lines, has sparked an intense moral and religious argument among people of various faith, including Muslim community. From the therapeutic point of view, amongst the currently available stem cells, hESCs show the greatest potential for the broadest range of cell replacement therapies and are regarded as the most commercially viable. This review focuses on the major ethical issues, particularly to Muslim community, related to human embryonic stem cells research with special emphasis on the moral status of the embryo and the beginning of life according to the Islamic ethics and rulings. In this paper, we also discuss some ethical positions towards embryonic stem cell research in the Islamic world, including official regulations existing in some Muslim countries. We examine the justification and the necessity on the usage of hESCs following the newly discovered Induced Pluripotent Stem Cells (IPSCs) in the laboratory. In addition, we supplement the discussions with the general views and positions from the other two Abrahamic religions i.e. Christianity and Judaism.