Effects of Aminoglycoside Antibiotics on Human Embryonic Stem Cell Viability during Differentiation In Vitro

Critical points for optimizing long-term culture and neural differentiation capacity of rodent and human neural stem cells to facilitate translation into clinical settings

Despite several decades of research on the nature and functional properties of neural stem cells, which brought great advances in regenerative medicine, there is still a plethora of ambiguous protocols and interpretations linked to their applications. Here, we present a whole spectrum of protocol elements that should be standardized in order to obtain viable cell cultures and facilitate their translation into clinical settings. Additionally, this review also presents outstanding limitations and possible problems to be encountered when dealing with protocol optimization. Most importantly, we also outline the critical points that should be considered before starting any experiments utilizing neural stem cells or interpreting their results.

A Beginner's Guide to Cell Culture: Practical Advice for Preventing Needless Problems

The cultivation of cells in a favorable artificial environment has become a versatile tool in cellular and molecular biology. Cultured primary cells and continuous cell lines are indispensable in investigations of basic, biomedical, and translation research. However, despite their important role, cell lines are frequently misidentified or contaminated by other cells, bacteria, fungi, yeast, viruses, or chemicals. In addition, handling and manipulating of cells is associated with specific biological and chemical hazards requiring special safeguards such as biosafety cabinets, enclosed containers, and other specialized protective equipment to minimize the risk of exposure to hazardous materials and to guarantee aseptic work conditions. This review provides a brief introduction about the most common problems encountered in cell culture laboratories and some guidelines on preventing or tackling respective problems.

In vitro testing and efficacy of poly-lactic acid coating incorporating antibiotic loaded coralline bioceramic on Ti6Al4V implant against Staphylococcus aureus

Biofilm formation on an implant surface is most commonly caused by the human pathogenic bacteria Staphylococcus aureus, which can lead to implant related infections and failure. It is a major problem for both implantable orthopedic and maxillofacial devices. The current antibiotic treatments are typically delivered orally or in an injectable form. They are not highly effective in preventing or removing biofilms, and they increase the risk of antibiotic resistance of bacteria and have a dose-dependent negative biological effect on human cells. Our aim was to improve current treatments via a localized and controlled antibiotic delivery-based implant coating system to deliver the antibiotic, gentamicin (Gm). The coating contains coral skeleton derived hydroxyapatite powders (HAp) that act as antibiotic carrier particles and have a biodegradable poly-lactic acid (PLA) thin film matrix. The system is designed to prevent implant related infections while avoiding the deleterious effects of high concentration antibiotics in implants on local cells including primary human adipose derived stem cells (ADSCs). Testing undertaken in this study measured the rate of S. aureus biofilm formation and determined the growth rate and proliferation of ADSCs. After 24 h, S. aureus biofilm formation and the percentage of live cells found on the surfaces of all 5%-30% (w/w) PLA-Gm-(HAp-Gm) coated Ti6Al4V implants was lower than the control samples. Furthermore, Ti6Al4V implants coated with up to 10% (w/w) PLA-Gm-(HAp-Gm) did not have noticeable Gm related adverse effect on ADSCs, as assessed by morphological and surface attachment analyses. These results support the use and application of the antibacterial PLA-Gm-(HAp-Gm) thin film coating design for implants, as an antibiotic release control mechanism to prevent implant-related infections.

Applying the Cytocentric Principles to Regenerative Medicine for Reproducibility

Purpose of Review

Cell and tissue products do not just reflect their present conditions; they are the culmination of all they have encountered over time. Currently, routine cell culture practices subject cell and tissue products to highly variable and non-physiologic conditions. This article defines five cytocentric principles that place the conditions for cells at the core of what we do for better reproducibility in Regenerative Medicine.

Recent Findings

There is a rising awareness of the cell environment as a neglected, but critical variable. Recent publications have called for controlling culture conditions for better, more reproducible cell products.

Summary

Every industry has basic quality principles for reproducibility. Cytocentric principles focus on the fundamental needs of cells: protection from contamination, physiologic simulation, and full-time conditions for cultures that are optimal, individualized, and dynamic. Here, we outline the physiologic needs, the technologies, the education, and the regulatory support for the cytocentric principles in regenerative medicine.

Anti-tuberculosis drugs used in a directly observed treatment short course (DOTS) schedule alter endocrine patterns and reduce the ovarian reserve and oocyte quality in the mouse

CONTEXT

Tuberculosis is one of the major infectious diseases, with people of reproductive age group having a high risk of infection.

AIMS

The present study was designed to understand the consequences of anti-tuberculosis drugs (ATDs) used in DOTS (directly observed treatment short course) schedule on ovarian function.

METHODS

Adult female Swiss albino mice were orally administered with combinations of ATDs used in the DOTS schedule every day for 4weeks. At 2weeks after the cessation of ATDs administration, the endocrine changes and ovarian function were assessed in mice.

KEY RESULTS

Administration of ATDs to mice resulted in a prolonged estrous cycle, reduced ovarian follicle reserve, alteration in FSH, LH, and progesterone level, and decreased the number of ovulated oocytes. Further, the degree of fragmentation, degeneration, abnormal distribution of cytoplasmic organelles, abnormal spindle organisation, and chromosomal misalignment were higher in oocytes that were ovulated following superovulation. Blastocysts derived from ATDs treated mice had significantly lower total cell numbers and greater DNA damage. A marginal increase in the number of resorbed fetuses was observed in all the ATDs treated groups except in the multidrug resistance treatment group. Male progeny of ATDs treated mice had decreased sperm count and lower progressive motility, while female progeny exhibited a non-significant reduction in the number of oocytes ovulated.

CONCLUSIONS

Theresults of this study suggest that ATDs can have significant adverse effects on the ovarian reserve, cytoplasmic organisation of oocytes, and can potentially cause transgenerational changes.

IMPLICATIONS

The findings of the present study indicate ovarian toxicity of ATDs and warrant further research in the direction of identifying alternate drugs with minimal toxicity, and strategies to mitigate the ovarian toxicity induced by these drugs.

Improved biological performance of human cartilage-derived progenitors in platelet lysate xenofree media in comparison to fetal bovine serum media

Primary articular cartilage-derived cells are among the preferred contenders for cell-based therapy approaches for cartilage repair. Limited access to primary human cartilage tissue necessitates the process of in vitro cell expansion to obtain sufficient cells for therapeutic purposes. Therapeutic outcomes of such cell-based approaches become highly dependent on the quality of the in vitro culture-expanded cells. The objective of this study was to determine the differential biological effects of human platelet lysate (hPL) xeno-free defined media vs FBS containing traditional media on primary human cartilage-derived cells. Our goal in pursuing this work was to identify a preferred xenofree media alternative, that can be used as a platform for expansion of cells intended for clinical applications. Primary cartilage-derived cells obtained from five patients were simultaneously cultured in two expansion media's: (1) traditional (DMEM+10%FBS+1%P/S) and (2) defined xenofree (Nutristem® complete media+0.5%hPL). Connective tissue progenitors (CTPs) were assayed by standard colony forming unit assay, morphology, proliferation in early and late passages, expression of MSC associated cell-surface markers (CD73, CD90 and CD105) and trilineage differentiation (adipogenesis, osteogenesis and chondrogenesis) were considered for comparison of biological performance. Early biological performance of primary cartilage-derived cells was significantly improved in Nutristem® expansion media in comparison to traditional expansion media with respect to (1) Colony forming efficiency tended to be higher (p = 0.058) and (2) CTPs formed larger colonies with respect to total cells per colony and colony area (p < 0.01). In the culture expanded cell population, Nutristem® expansion media was superior to traditional expansion media with respect to: (1) overall proliferation rate through passages 1-4 (p = 0.027), (2) total cells harvested at end of passage 4 (p = 0.028) and (3) total positive stain area of CD73 (p = 0.006), CD90 (p = 0.001) and CD105 (p = 0.049). Nutristem®-hPL expanded cells when differentiated in respective xenofree serum-free defined MSCgo™ differentiated media's, also showed significant improvement in adipogenic, osteogenic and chondrogenic marker expression. Overall, we convincingly demonstrated that a low concentration of hPL in combination with defined xenofree media is an effective and economic growth supplement to culture expand primary cartilage-derived cells. It can be manufactured under cGMP conditions to improve clinical-grade cell products' quality for therapeutic applications.

Developmental modeling of hepatogenesis using obese iPSCs-hepatocyte differentiation uncovers pathological features

Obesity is a multigene disorder. However, in addition to genetic factors, environmental determinants also participate in developing obesity and related pathologies. Thus, obesity could be best described as a combination of genetic and environmental perturbations often having its origin during the early developmental period. Environmental factors such as energy-dense food and sedentary lifestyle are known to be associated with obesogenicity. However, the combinatorial effects of gene-environment interactions are not well understood. Understanding the role of multiple genetic variations leading to subtle gene expression changes is not practically possible in monogenic or high-fat-fed animal models of obesity. In contrast, human induced pluripotent stem cells (hiPSCs) from individuals with familial obesity or an obesogenic genotype could serve as a good model system. Herein, we have used hiPSCs generated from normal and genetically obese subjects and differentiated them into hepatocytes in cell culture. We show that hepatocytes from obese iPSCs store more lipids and show increased cell death than normal iPSCs. Whole transcriptome analyses in both normal and obese iPSCs treated with palmitate compared to control revealed LXR-RXR and hepatic fibrosis pathways were enriched among other pathways in obese iPSCs compared to normal iPSCs. Among other genes, increased CD36 and CAV1 expression and decreased expression of CES1 in obese iPSCs could have been responsible for excess lipid accumulation, resulting in differential expression of genes associated with hepatic fibrosis, a key feature of non-alcoholic fatty liver disease (NAFLD). Our results demonstrate that iPSCs derived from genetically obese subjects could serve as an excellent model to understand the effects of this multigene disorder on organ development and may uncover pathologies of NAFLD, which is highly associated with obesity.

Standardizing Patient-Derived Organoid Generation Workflow to Avoid Microbial Contamination From Colorectal Cancer Tissues

The use of patient-derived organoids (PDO) as a valuable alternative to in vivo models significantly increased over the last years in cancer research. The ability of PDOs to genetically resemble tumor heterogeneity makes them a powerful tool for personalized drug screening. Despite the extensive optimization of protocols for the generation of PDOs from colorectal tissue, there is still a lack of standardization of tissue handling prior to processing, leading to microbial contamination of the organoid culture. Here, using a cohort of 16 patients diagnosed with colorectal carcinoma (CRC), we aimed to test the efficacy of phosphate-buffered saline (PBS), penicillin/streptomycin (P/S), and Primocin, alone or in combination, in preventing organoid cultures contamination when used in washing steps prior to tissue processing. Each CRC tissue was divided into 5 tissue pieces, and treated with each different washing solution, or none. After the washing steps, all samples were processed for organoid generation following the same standard protocol. We detected contamination in 62.5% of the non-washed samples, while the use of PBS or P/S-containing PBS reduced the contamination rate to 50% and 25%, respectively. Notably, none of the organoid cultures washed with PBS/Primocin-containing solution were contaminated. Interestingly, addition of P/S to the washing solution reduced the percentage of living cells compared to Primocin. Taken together, our results demonstrate that, prior to tissue processing, adding Primocin to the tissue washing solution is able to eliminate the risk of microbial contamination in PDO cultures, and that the use of P/S negatively impacts organoids growth. We believe that our easy-to-apply protocol might help increase the success rate of organoid generation from CRC patients.

Prenatal toxicity of the environmental pollutants on neuronal and cardiac development derived from embryonic stem cells

Pesticides, antibiotics, and industrial excipients are widely used in agriculture, medicine, and chemical industry, respectively. They often end up in the environment, not only being not easily decomposed but also being accumulated. Moreover, they may cause serious toxic problems such as reproductive and developmental defects, immunological toxicity, and carcinogenesis. Hence, they are called environmental pollutants. It is known that the environmental pollutants easily enter the body through various channels such as respiration, ingestion of food, and skin contact etc. in everyday life. If they enter the mother through the placenta, they can cause the disturbance in embryo development as well as malfunction of organs after birth because early prenatal developmental process is highly sensitive to toxic chemicals and stress. Embryonic stem cells (ESCs) that consist of inner cell mass of blastocyst differentiate into distinct cell lineages via three germ layers such as the ectoderm, mesoderm, and endoderm due to their pluripotency. The differentiation process initiated from ESCs reflects dynamic nature of embryonic development. Therefore, ESCs have been used as a useful tool to investigate early developmental toxicities of a variety of stress. Based on relatively recent scientific results, this review would address toxicity of a few chemical substances that have been widely used as pesticide, antibiotics, and industrial excipient on ESCs based-prenatal developmental process. This review further suggests how they act on the viability of ESCs and/or early stages of cardiac and neuronal development derived from ESCs as well as on expression of pluripotency and/or differentiation markers through diverse mechanisms.

Fine Tuning of Hepatocyte Differentiation from Human Embryonic Stem Cells: Growth Factor vs. Small Molecule-Based Approaches

Human embryonic stem cells (hESCs) are being utilized in diverse areas of studies such as development and disease modeling, cell replacement therapy, or drug toxicity testing because of their potential to be differentiated into any cell type in the body. The directed differentiation of hESCs into hepatocytes could provide an invaluable source of liver cells for various liver-based applications. Therefore, several protocols have been established in the past for hESC-hepatocyte differentiation based on the knowledge of signaling pathways and growth factors involved in different stages of embryonic hepatogenesis. Although successful derivation of hepatocytes has been achieved through these protocols, the efficiency is not always ideal. Herein, we have tested several combinations of published protocols, for example, growth factor vs. small molecule and different time durations of treatment for definitive endoderm (DE) induction and further hepatocyte differentiation to develop an efficient DE induction and hepatocyte differentiation in a highly reproducible manner based on the stage-specific marker expression and functional analysis.