Sandeep Kumar Vishwakarma

Current concept in neural regeneration research: NSCs isolation, characterization and transplantation in various neurodegenerative diseases and stroke: A review

Since last few years, an impressive amount of data has been generated regarding the basic in vitro and in vivo biology of neural stem cells (NSCs) and there is much far hope for the success in cell replacement therapies for several human neurodegenerative diseases and stroke. The discovery of adult neurogenesis (the endogenous production of new neurons) in the mammalian brain more than 40 years ago has resulted in a wealth of knowledge about stem cells biology in neuroscience research. Various studies have done in search of a suitable source for NSCs which could be used in animal models to understand the basic and transplantation biology before treating to human. The difficulties in isolating pure population of NSCs limit the study of neural stem behavior and factors that regulate them. Several studies on human fetal brain and spinal cord derived NSCs in animal models have shown some interesting results for cell replacement therapies in many neurodegenerative diseases and stroke models. Also the methods and conditions used for in vitro culture of these cells provide an important base for their applicability and specificity in a definite target of the disease. Various important developments and modifications have been made in stem cells research which is needed to be more specified and enrolment in clinical studies using advanced approaches. This review explains about the current perspectives and suitable sources for NSCs isolation, characterization, in vitro proliferation and their use in cell replacement therapies for the treatment of various neurodegenerative diseases and strokes.

Repopulation of decellularized whole organ scaffold using stem cells: an emerging technology for the development of neo-organ

Demand of donor organs for transplantation in treatment of organ failure is increasing. Hence there is a need to develop new strategies for the alternative sources of organ development. Attempts are being made to use xenogenic organs by genetic manipulation but the organ rejection against human always has been a major challenge for the survival of the graft. Advancement in the genetic bioengineering and combination of different allied sciences for the development of humanized organ system, the therapeutic influence of stem cell fraction on the reconstitution of organ architecture and their regenerative abilities in different tissues and organs provides a better approach to solve the problem of organ shortage. However, the available strategies for generating the organ/tissue scaffolds limit its application due to the absence of complete three-dimensional (3D) organ architecture, mechanical strength, long-term cell survival, and vascularization. Repopulation of whole decellularized organ scaffolds using stem cells has added a new dimension for creating new bioengineered organs. In recent years, several studies have demonstrated the potential application of decellularization and recellularization approach for the development of functional bio-artificial organs. With the help of established procedures for conditioning, extensive stem cells and organ engineering experiments/transplants for the development of humanized organs will allow its preclinical evaluation for organ regeneration before translation to the clinic. This review focuses on the major aspects of organ scaffold generation and repopulation of different types of whole decellularized organ scaffolds using stem cells for the functional benefit and their confines.

Hepatic stem cells: A viable approach for the treatment of liver cirrhosis

Liver cirrhosis is characterized by distortion of liver architecture, necrosis of hepatocytes and regenerative nodules formation leading to cirrhosis. Various types of cell sources have been used for the management and treatment of decompensated liver cirrhosis. Knowledge of stem cells has offered a new dimension for regenerative therapy and has been considered as one of the potential adjuvant treatment modality in patients with end stage liver diseases (ESLD). Human fetal hepatic progenitor cells are less immunogenic than adult ones. They are highly propagative and challenging to cryopreservation. In our earlier studies we have demonstrated that fetuses at 10-18 wk of gestation age contain a large number of actively dividing hepatic stem and progenitor cells which possess bi-potent nature having potential to differentiate into bile duct cells and mature hepatocytes. Hepatic stem cell therapy for the treatment of ESLD is in their early stage of the translation. The emerging technology of decellularization and recellularization might offer a significant platform for developing bioengineered personalized livers to come over the scarcity of desired number of donor organs for the treatment of ESLD. Despite these significant advancements long-term tracking of stem cells in human is the most important subject nowadays in order to answer several unsettles issues regarding the route of delivery, the choice of stem cell type(s), the cell number and the time-point of cell delivery for the treatment in a chronic setting. Answering to these questions will further contribute to the development of safer, noninvasive, and repeatable imaging modalities that could discover better cell therapeutic approaches from bench to bed-side. Combinatorial approach of decellularization and nanotechnology could pave a way towards the better understanding in determination of cell fate post-transplantation.

Potential role of stem cells in severe spinal cord injury: current perspectives and clinical data

Stem cell transplantation for spinal cord injury (SCI) along with new pharmacotherapy research offers the potential to restore function and ease the associated social and economic burden in the years ahead. Various sources of stem cells have been used in the treatment of SCI, but the most convincing results have been obtained with neural progenitor cells in preclinical models. Although the use of cell-based transplantation strategies for the repair of chronic SCI remains the long sought after holy grail, these approaches have been to date the most successful when applied in the subacute phase of injury. Application of cell-based strategies for the repair and regeneration of the chronically injured spinal cord will require a combinational strategy that may need to include approaches to overcome the effects of the glial scar, inhibitory molecules, and use of tissue engineering strategies to bridge the lesion. Nonetheless, cell transplantation strategies are promising, and it is anticipated that the Phase I clinical trials of some form of neural stem cell-based approach in SCI will commence very soon.

In vitro quantitative and relative gene expression analysis of pancreatic transcription factors Pdx-1, Ngn-3, Isl-1, Pax-4, Pax-6 and Nkx-6.1 in trans-differentiated human hepatic progenitors.

Diabetes is a major health concern throughout the world because of its increasing prevalence in epidemic proportions. β‐Cell deterioration in the pancreas is a crucial factor for the progression of diabetes mellitus. Therefore, the restoration of β‐cell mass and its function is of vital importance for the development of effective therapeutic strategies and most accessible cell sources for the treatment of diabetes mellitus.

Magnetic nanoparticle tagged stem cell transplantation in spinal cord injury: A promising approach for targeted homing of cells at the lesion site

Spinal cord injury (SCI) is a devastating condition that leads to significant morbidity. It results in a permanent neurological deficit due to damage of motor neurons. The resultant lesion is a barrier for “communication” between the brain and peripheral tissues, both at the effector as well as the receptor level. One of the primary goals of tissue engineering is to bridge the gap created by SCI and reestablish the damaged connections.[1,2] Stem cell transplantation has a great potential in designing effective therapies for SCI. Despite extensive therapeutic benefits, lack of a noninvasive and efficient cell delivery system, and poor engraftment limits the current role of stem cell therapies in SCI. Application of nanotechnology has already proven its potential in addressing some of these fundamental issues. The development of superparamagnetic iron oxide nanoparticles (SPIONPs) has provided a better pathway for the efficient delivery of stem cells at the target location.[3] A recent study by Tukmachev et al. has demonstrated the potential of SPIONPs in facilitating the homing of mesenchymal stem cells (MSCs) at the lesion site in a rat model of SCI.[4] The study demonstrated the accumulation of SPIO‐labeled MSCs in the vicinity of the lesion site from a distance of 10 cm from the site of injury by using an external magnetic system of 1.2T [Figure 1]. This study provides a better hope for future magnetic nanoparticle‐based delivery of stem cells at the desired site. However, few of the most important issues in cell‐based therapies for SCI are the formation of a glial scar and the regeneration of neurons and glia that undergo cell death soon after injury. Therefore, selection of the appropriate variety of stem cells has to be done for an effective treatment. In the same direction, our center has developed a novel gadolinium‐SPIO (Gd‐SPIO) magnetic nanoparticle by a soft chemical approach that provides a high biocompatibility. Gd‐SPIONPs produce enhanced sensitivity by decreasing the relaxation time of the proton longitudinally (T1) as well as transversely (T2). Thus, it may be a better choice for obtaining a contrast magnetic resonance imaging. The extremely low concentrations of the magnetic nanoparticles prevents the toxic side effects of free gadolinium ions from developing. Apart from its use in the generation of excellent contrast images, Gd‐SPIONPs have also shown a paramagnetic behavior due to their much greater proton relaxation per atom of iron than gadolinium. The paramagnetic activity of Gd‐SPIONPs in the presence of external magnetic fields is accompanied by its safe degradation and clearance from the biological system (unpublished data). Hence, directed transplantation of neuronal cells labeled with Gd‐SPIONPs may be considered as a better strategy for obtaining high contrast imaging and noninvasive cell trapping at the desired site. This combinational strategy of Gd‐SPIO labeled neuronal cells for the regeneration of chronically injured spinal cord would overcome the effects of the glial scar, inhibitory molecules, and help in utilizing tissue engineering strategies to bridge the lesion more effectively. Correspondence

Use of Biocompatible Sorafenib-gold Nanoconjugates for Reversal of Drug Resistance in Human Hepatoblatoma Cells

The present study identifies the potential of highly biocompatible SF-GNP nano-conjugate to enhance the chemotherapeutic response to combat drug resistance in cancer cells. We developed a stable colloidal suspension of sorafenib-gold nanoconjugate (SF-GNP) of <10u2009nm size in aqueous medium for reverting the cancer drug resistance in SF-resistant HepG2 cells in a 3D ex-vivo model system. In-vivo biocompatibility assay of SF-GNPs showed absence of systemic toxicological effects including hematological, biochemical and histological parameters. More importantly, the histopathological analysis of vital organs such as liver, brain, lung, kidney and heart showed very least or no sign of inflammation, cell infiltration, necrosis, tissue disorganization or fibrotic reactions after intra-peritoneal administration of SF-GNP nanoconjugates in animals. However, SF-GNP nanoconjugates significantly reduced (>80%) the percentage cell survival and thexa0size andxa0number of SF resistant solid tumor colonies of HepG2 cells in 3D model system.xa0The exposure of SF-GNP nanoconjugate to SF resistant HepG2 cell colonies also provided evidence forxa0anti-proliferative effect and reversal of drug resistance by elucidating the molecular regulatory mechanisms of extracellular matrix factor (CD147), tumor growth factor (TGF-β), hepatoma upregulated protein (hURP) and drug transporter (ABCG-2).

Real-time cellular and molecular dynamics of bi-metallic self-therapeutic nanoparticle in cancer cells

Since last decades various kinds of nanoparticles have been functionalized to improve their biomedical applications. However, the biological effect of un-modified/non-functionalized bi-metallic magnetic nanoparticles remains under investigated. Herein we demonstrate a multifaceted non-functionalized bi-metallic inorganic Gd-SPIO nanoparticle which passes dual high MRI contrast and can kill the cancer cells through several mechanisms. The results of the present study demonstrate that Gd-SPIO nanoparticles have potential to induce cancer cell death by production of reactive oxygen species and apoptotic events. Furthermore, Gd-SPIO nanoparticles also enhance the expression levels of miRNA-199a and miRNA-181a-7p which results in decreased levels of cancer markers such as C-met, TGF-β and hURP. One very interesting finding of this study reveals side scatter-based real-time analysis of nanoparticle uptake in cancer cells using flow cytometry analysis. In conclusion, this study paves a way for future investigation of un-modified inorganic nanoparticles to purport enhanced therapeutic effect in combination with potential anti-tumor drugs/molecules in cancer cells.

Genetic Polymorphisms of X-ray Repair Cross-Complementing Group 1 and Apurinic/Apyrimidinic Endonuclease-1 in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous collection of conditions characterized by irreversible expiratory airflow limitation. The disease is interspersed with exacerbations; periods of acute symptomatic, physiological, and functional deterioration. The present study was designed to investigate the role of X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1 (APE1) polymorphisms and the risk of COPD. Blood samples from 354 unrelated subject (age range 18–60xa0years; 156 with COPD, 198 healthy controls) were collected. Genomic DNA was isolated and genotyped for XRCC1 Arg399Gln and APE1 Asp148Glu using a confronting two pair primers polymerase chain reaction. GA genotype of XRCC1 gene was found to be predominant in the COPD group compared to controls with 1.86-fold increased risk for COPD (OR 1.86, 95xa0% CI 1.20–2.88, pu2009=u20090.0013). TG genotype of APE1 was found to be predominant in COPD group compared to controls with the difference being statistically significant (OR 1.68, 95xa0% CI 1.08–2.61, pu2009=u20090.0043). The GA haplotype was found to be predominant in COPD than controls with a 2.19-fold significant increase (OR 2.19, 95xa0% CI 1.46–3.28, pu2009=u20090.003). Polymorphism in XRCC1 and APE1 gene is associated with an increased risk of COPD.

Effect of Genetic Polymorphisms in CD14 and TLR4 on Cardiomyopathy

Background: We investigated polymorphisms of immune related genes (CD14 and TLR4) and explore the associations of these variants and risk of CM. nMethod: We detected SNPs of CD14 (-159C>T) and TLR4 (299 A>G) using the polymerase chain reaction (PCR) with peripheral blood samples from 141 patients with CM and 198 healthy people, further analyzing their relations with the risk of CM. nResult: The CT genotype of CD14 gene was found to be associated with CM and 1.84 folds increased risk to CM when compared to CC genotype (OR 1.84, 95% CI 1.18–2.88, P=0.0051). Heterozygotes (AG) of TLR4 gene were found to be predominant in the CM group when compared to controls (50.4%, 38.4% respectively, P=0.0081) with 1.79 folds increased risk for CM, which was statistically significant (OR 3.79, 95% CI 1.15–2.80, P=0.0081). nConclusion: Polymorphism in CD14 and TLR4 gene is associated with an increased risk of CM. The combined effects of polymorphisms within innate immune genes of CD14 and TLR14 may contribute to a high risk of CM.