Stem cell-based approaches in cardiac tissue engineering: controlling the microenvironment for autologous cells.

Cardiovascular disease is one of the leading causes of mortality worldwide. Cardiac tissue engineering strategies focusing on biomaterial scaffolds incorporating cells and growth factors are emerging as highly promising for cardiac repair and regeneration. The use of stem cells within cardiac microengineered tissue constructs present an inherent ability to differentiate into cell types of the human heart. Stem cells derived from various tissues including bone marrow, dental pulp, adipose tissue and umbilical cord can be used for this purpose. Approaches ranging from stem cell injections, stem cell spheroids, cell encapsulation in a suitable hydrogel, use of prefabricated scaffold and bioprinting technology are at the forefront in the field of cardiac tissue engineering. The stem cell microenvironment plays a key role in the maintenance of stemness and/or differentiation into cardiac specific lineages. This review provides a detailed overview of the recent advances in microengineering of autologous stem cell-based tissue engineering platforms for the repair of damaged cardiac tissue. A particular emphasis is given to the roles played by the extracellular matrix (ECM) in regulating the physiological response of stem cells within cardiac tissue engineering platforms.

Therapeutic angiogenesis: From conventional approaches to recent nanotechnology-based interventions.

Intentional and regulated induction of blood vessels formation which is generally referred to as therapeutic angiogenesis has a lot of potential in the management of various kinds of ischemic complications as well as in wound healing, bone regeneration and tissue engineering. Conventionally, therapeutic angiogenesis relies on the controlled application of growth factors that helps to initiate the formation of blood vessels in the target tissues and bioengineered constructs. The emergence of nanotechnology in medicine, particularly its application in molecular medicine has the potential for a tremendous progress in the therapeutic angiogenesis interventions. Although a good number of systems, which include growth factor delivery, use of gene therapeutic agents, and nanomaterials, are in experimental or preclinical phase, there is a huge potential for them in the clinical implication in upcoming years. In this article, we review the main advances of therapeutic angiogenesis over the past few years, explore the application prospects and discuss about the principles, approaches, importance and challenges with the aim of facilitating its clinical translation in near future.

Design, graph theoretical analysis and in silico modeling of Dunaliella bardawil biomass encapsulated keratin nanoparticles: a scaffold for effective glucose utilization.

The aim of the present study is to develop keratin nanoparticles (NPs) encapsulated in Dunaliella bardawil (D. bardawil) biomass, in order to improve their glucose uptake in 3T3-L1 adipocytes. The graph theoretical approach has provided a platform to identify PTP-1B and AMPK as an effective drug target. Docking results of the active constituents of D. bardawil showed a strong interaction with binding pockets of identified PTP-1B and AMPK. The encapsulation efficiency, drug release, stability and physicochemical properties of prepared NPs were analyzed using UV-visible spectrophotometry, Fourier transform infrared spectrophotometry, x-ray diffraction, scanning and tunneling electron microscopy, and Zeta size analysis. Further, encapsulated keratin NPs were screened for their in vitro cytotoxicity and glucose uptake studies. The study report of biomass encapsulated keratin NPs showed no toxicity at lower concentrations and 81.23 ± 6.56% cellular viability at 30 µg in 3T3-L1 adipocytes. Moreover, the effect of keratin NPs (30 µg) on glucose utilization (58.56 ± 4.54%) was higher than that of Metformin (10 µM) or insulin (10 µM). The observed higher level of glucose utilization may lead to the development of novel ways to enhance biological activities.

Estimation of Need for Palliative Care among Noncancer Patients Attending a Tertiary Care Hospital.

CONTEXT: Palliative care services, until recently, were mainly restricted to cancer patients with incurable diseases. Hence, evaluative studies of palliative care are sparse in areas other than oncology. AIMS: To estimate what proportion of patients attending the Departments of Neurology, Cardiology, and Nephrology of Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, required palliative care and to identify the palliative care needs of those patients. SETTINGS AND DESIGN: This was an exploratory descriptive study conducted in the three departments of JIPMER. MATERIALS AND METHOD: There was no predetermined sample size for the study. The participants were all adult inpatients and outpatients who were in need of palliative care in the departments of Cardiology, Nephrology, and Neurology on the day of study. STATISTICAL ANALYSIS: Percentage distribution was used to analyze the categorical variables such as education, gender, age, patients in need of palliative care, and their needs. RESULTS: The study showed that one in ten non-cancer patients in tertiary care hospitals may require palliative care services. Apart from issues in physical domain, a substantial proportion of participants also had issues in the psychological, emotional, and financial domains. CONCLUSION: This study highlights the need for incorporation and initiation of palliative care services in other non-cancer specialties in tertiary care hospitals to ensure holistic management of such cases. Counseling service has also to be rendered as part of palliative care since a good share of the patients had psychological and emotional issues.

Serotonin reuptake inhibitor citalopram inhibits GnRH synthesis and spermatogenesis in the male zebrafish.

Selective serotonin reuptake inhibitors (SSRIs) are widely used antidepressants for the treatment of depression. However, SSRIs cause sexual side effects such as anorgasmia, erectile dysfunction, and diminished libido that are thought to be mediated through the serotonin (5-hydroxytryptamine, 5-HT) system. In vertebrates, gonadotropin-releasing hormone (GnRH) neurons play an important role in the control of reproduction. To elucidate the neuroendocrine mechanisms of SSRI-induced reproductive failure, we examined the neuronal association between 5-HT and GnRH (GnRH2 and GnRH3) systems in the male zebrafish. Double-label immunofluorescence and confocal laser microscopy followed by three-dimensional construction analysis showed close associations between 5-HT fibers with GnRH3 fibers and preoptic-GnRH3 cell bodies, but there was no association with GnRH2 cell bodies and fibers. Quantitative real-time PCR showed that short-term treatment (2 wk) with low to medium doses (4 and 40 µg/L, respectively) of citalopram significantly decreased mRNA levels of gnrh3, gonadotropins (lhb and fshb) and 5-HT-related genes (tph2 and sert) in the male zebrafish. In addition, short-term citalopram treatment significantly decreased the fluorescence density of 5-HT and GnRH3 fibers compared with controls. Short-term treatment with low, medium, and high (100 µg/L) citalopram doses had no effects on the profiles of different stages of spermatogenesis, while long-term (1 mo) citalopram treatment with medium and high doses significantly inhibited the different stages of spermatogenesis. These results show morphological and functional associations between the 5-HT and the hypophysiotropic GnHR3 system, which involve SSRI-induced reproductive failures.

Role of serotonin in fish reproduction.

The neuroendocrine mechanism regulates reproduction through the hypothalamo-pituitary-gonadal (HPG) axis which is evolutionarily conserved in vertebrates. The HPG axis is regulated by a variety of internal as well as external factors. Serotonin, a monoamine neurotransmitter, is involved in a wide range of reproductive functions. In mammals, serotonin regulates sexual behaviors, gonadotropin release and gonadotropin-release hormone (GnRH) secretion. However, the serotonin system in teleost may also play unique role in the control of reproduction as the mechanism of reproductive control in teleosts is not always the same as in the mammalian models. In fish, the serotonin system is also regulated by natural environmental factors as well as chemical substances. In particular, selective serotonin reuptake inhibitors (SSRIs) are commonly detected as pharmaceutical contaminants in the natural environment. Those factors may influence fish reproductive functions via the serotonin system. This review summarizes the functional significance of serotonin in the teleosts reproduction.

Molecular and cellular characterization of expanded and cryopreserved human limbal epithelial stem cells reveal unique immunological properties.

Transplantation of ex vivo expanded autologous limbal stem cells into the diseased eye of patients with limbal stem cell deficiency (LSCD) has been in practice worldwide. However, isolation of limbal tissue from the normal eye of the patient with unilateral LSCD still remains a major concern for the donor. More importantly, autologous cell transplantation is not a viable option for patients with bilateral LSCD. The objective of the current study was to determine the expansion potential of human limbal epithelial stem cells (hLESCs) for their possible use in allo-transplantation. A total of six limbal biopsy samples were cultured and expanded in vitro up to passage level 1 (P-1), at which point the hLESCs were cryopreserved. Semi-quantitative RT-PCR and immunophenotypic analysis revealed that hLESCs obtained before and after cryopreservation retained the expression of major limbal epithelial stem cell markers such as p63, SSEA-4, ABCG2, cytokeratin 19 (CK19), integrin ß1 and vimentin. One notable difference was that while P-0 hLESCs expressed HLA-DR mRNA, no HLA-DR gene expression was observed with the expanded and cryopreserved samples. Human LESCs did not express costimulatory proteins CD80 or B7-DC but expressed significant levels of CD86, B7-H1 and HLA-ABC molecules on the cell surface. Treatment of hLESCs with IFN-γ induced the expression of HLA-DR, indoleamine 2,3-dioxygenase (IDO) and HLA-G on these cells. Cultured hLESCs were unable to stimulate allogeneic T cell proliferation in vitro even in the presence of pro-inflammatory cytokine, IFN-γ. These results indicate that cryopreserved hLESCs are non-immunogenic in nature and express negative immunoregulatory molecules which may be critical for their survival in an allogeneic environment.