Shashi Singh

Centre for Cellular and Molecular Biology | CCMB · Centre for Cellular and Molecular Biology (Council of Scientific and Industrial Research)

Islets organoids would have value in the cell replacement therapy for diabetes apart from usual personalized drug screening routes. Generation of a large number of Islets like clusters, with ability to respond to glucose stimulation appears to be an ideal choice. In this study we have generated islet organoids with the ability to respond to glucose...

Development of an artificial tissue by tissue engineering is witnessed to be one of the long lasting clarified solutions for the damaged tissue function restoration. To accomplish this, a scaffold is designed as a cell carrier in which the extracellular matrix (ECM) performs a prominent task of controlling the inoculated cell’s destiny. ECM composi...

Ideally, a bioscaffold should mimic the characteristics of an extracellular matrix of a living organ of interest. The present study deals with the formation of composite scaffolds of collagen with gum arabic. Collagen was cross-linked with oxidized gum arabic having aldehyde groups to form a porous block. By changing the oxidation level of gum arab...

Insulin resistance is associated with obesity and can lead to several metabolic disorders including type II diabetes , nonalcoholic fatty liver disease and cardiovascular problems. Search for the small molecules which can either induce or mimic the insulin action are of great interest and can be utilized to manage insulin resistance. There are seve...

Background: Tissue engineering centers on creating a niche similar to the natural one, with a purpose of developing an organ construct. A natural scaffold can replace none while creating a scaffold unique to each tissue in composition, architecture and cues that regulate the character of cells. Methods: Whole pancreas from mouse was decellulariz...

An integration free iPSC line was generated from fibroblast obtained from the skin of an aborted fetus in feeder free conditions using episomal based vectors expressing the pluripotency factors. The cell line generated was characterized and tested for pluripotency both in vitro and in vivo by teratoma formation and differentiation into defined line...

Extracellular matrix of each tissue is unique in composition, architecture and finer details that support the very identity of the organ by regulating the status/character of the cells within it. Tissue engineering centers around creating a niche similar to the natural one, with a purpose of developing an organ/oid. In this study, whole organ decel...

The potential of environmental release enhances with increased commercial applications of the nanomaterials. In this work, a simple and efficient test to estimate the acute toxicity of nanoparticles is carried out on Artemia species and their hatching rates. We have tested six different engineered nanoparticles (silver, gold, copper oxide, zinc oxi...

The potential of environmental release enhances with increased commercial applications of the nanomaterials. A simple and efficient test to estimate the acute toxicity of nanoparticles is carried out in this work using Artemia species and their hatching rate. We have tested six different engineered nanoparticles (silver, gold, copper oxide, zinc ox...

Herein we demonstrate a bio-inspired method involving macromolecular assembly of anionic polypeptide with cationic peptide-oligomer that allows for in-situ encapsulation of antibiotics like tetracycline in CaCO3 microstructure. In a single step one-pot process the encapsulation of the drug occurs under desirable environmentally benign conditions re...

Within EU FP7 project NANOVALID the (eco)toxicity of 7 well-characterized engineered nanomaterials (NMs) was evaluated by 15 bioassays in 4 laboratories. The highest tested nominal concentration of NMs was 100 mg/l. The panel of the bioassays yielded the following toxicity order: Ag > ZnO > CuO > TiO2>MWCNTs > SiO2>Au.Ag, ZnO and CuO proved very to...

Within the FP7 EU project NanoValid a consortium of six partners jointly investigated the hazard of silver nanoparticles (AgNPs) paying special attention to methodical aspects that are important for providing high-quality ecotoxicity data. Laboratories were supplied with the same original stock dispersion of AgNPs. All partners applied a harmonised...

The chemically treated Labeo rohita scale is used for synthesizing hydroxyapatite (HAp) biomaterials. Thermogravimetric and differential thermal analyses of fish scale materials reveal the different phase changes with temperature and find out the suitable calcination temperatures. The composition and structures of wet ball-milled calcined HAp powde...

Pressing need for utilization of injectables/fillers in various forms of orthopaedic treatments/surgeries commands an equal demand for better graft material. Injectable bone graft material based on biomimetically synthesized nanohydroxyapatite was developed and subjected to ball milling for different times; three materials thus produced were evalua...

Abstract Titanium dioxide nanoparticles (TiO(2) NPs), widely used in consumer products, paints, pharmaceutical preparations and so on, have been shown to induce cytotoxicity, genotoxicity and carcinogenic responses in vitro and in vivo. The present study revealed that TiO(2) NPs induce significant (p < 0.05) oxidative DNA damage by the Fpg-Comet as...

Synthetic oligopeptides containing polyhydroxylated bicyclic dipeptide (GlcTap) are investigated for their adhesion properties. The non-natural amino acid building block composed of GlcTap is derived from glucuronic acid and mimics the hydroxyl-amino acids of the natural proteins. Peptide oligomers of GlcTap flanked by the amino acids Tyr and Ly...

Biology of Mesenchymal Stem Cells from various sources and their potential use in Tissue Engineering

The external, oral and buccopharyngeal morphologies of Nasikabatrachus sahyadrensis tadpoles were studied using ste-reoscopic and scanning electron microscopy. Using DNA barcodes, taxonomic identity of the tadpoles was established and tadoples of N. sahyadrensis were reared in semi-natural conditions. Development in the species from hatching to met...

We present a comparison of immune-properties of mesenchymal stem cells (MSC) isolated from human placenta, umbilical cord matrix, adipose, and bone marrow. MSC collected from all these sources possess low levels of MHC-I and lacked MHC-II. These cells inhibited the mixed lymphocytic reaction in culture conditions when incubated with human allogenei...

Reconstruction of critical sized bone injuries is a major problem that continues to inspire the design of new materials and grafts. Natural ceramics (hydroxyapatite (HA) coralline HA, or synthetic HA) and β-tricalcium phosphate (β-TCP) are being explored for use as scaffolds in bone tissue engineering, among several other materials. The present stu...

Counter-ion condensation of Poly(L-Lysine) in the presence of pyranine-3 generates spherical coacervates, which then template the assembly of silica nanoparticles to form microcapsule structures that dynamically control the optical ratiometric sensing of both the change in pH and release of the probe molecule.

A novel Gram-staining-negative, rod-shaped, non-motile bacterium, designated strain LW9(T), was isolated from a water sample collected from Lonar Lake of Buldhana district, Maharashtra, India. Colonies and broth cultures were reddish orange due to the presence of carotenoid pigments. Strain LW9(T) was positive for catalase, ornithine decarboxylase...

Cell-free culture supernatants of five psychrophilic bacteria Pseudomonas antarctica, Pseudomonas proteolytica, Pseudomonas meridiana, Arthrobacter kerguelensis and Arthrobacter gangotriensis and two mesophilic bacteria Bacillus indicus and Bacillus cecembensis have been used to synthesize silver nanoparticles (AgNPs). The AgNPs were characterized...

Toxicity of engineered nanomaterials (ENMs), such as metal oxides, has been of concern among environmental and health scientists. For ecotoxicity studies of ENMs, it is important to assess nanoparticle uptake and correlate it with the cellular response. However, due to nonavailability of adequate methods for assessing cellular uptake of ENMs, there...

Short peptides have been identified from amyloidogenic proteins that form amyloid fibrils in isolation. The hexapeptide stretch ²¹DIDLHL²⁶ has been shown to be important in the self-assembly of the Src homology 3 (SH3) domain of p85 alpha subunit of bovine phosphatidylinositol-3-kinase (PI3-SH3). The SH3 domain of chicken brain alpha- spectrin, whi...

Extensive use of engineered nanoparticle (ENP)-based consumer products and their release into the environment have raised a global concern pertaining to their adverse effects on human and environmental health. The safe production and use of ENPs requires improvement in our understanding of environmental impact and possible ecotoxicity. This study e...

Inhibiting Hsp90 chaperone roles using 17AAG induces cytostasis or apoptosis in tumor cells through destabilization of several mutated cancer promoting proteins. Although mitochondria are central in deciding the fate of cells, 17AAG induced effects on tumor cell mitochondria were largely unknown. Here, we show that Hsp90 inhibition with 17AAG first...

Different bone injuries may call for different types of bone grafting and unique bone graft materials. The ideal bone-graft substitute is biocompatible, bioresorbable, osteoconductive, osteoinductive; in short structurally similar to bone, easy to use, and cost-effective. The current choice of bone grafts is the autograft since it possesses all the...

Titanium dioxide nanoparticles (TiO(2) NPs) are among the top five NPs used in consumer products, paints and pharmaceutical preparations. Since, exposure to such nanoparticles is mainly through the skin and inhalation, the present study was conducted in the human epidermal cells (A431). A mild cytotoxic response of TiO(2) NPs was observed as eviden...

We performed an extensive study on mitochondrial dysfunction in chronic periodontitis (CP). Electron microscopic analysis of gingival cells revealed abnormal mitochondria in 60% of the patients. Mitochondrial membrane potential and oxygen consumption of gingival cells were reduced by 4 fold and 5.8 fold, respectively; whereas ROS production was inc...

Nanomaterials are being made for use in various fields in biology from sensors to clutches. Nanomaterials may be perceived, in bizarre ways by the cells. Starting from the membrane to the nucleus, each component of the cell could have a new response. Mesenchymal Stem Cells (MSC) isolated from human placenta, Wharton's jelly, cord blood, fetal bone...

Titanium dioxide nanoparticles (TiO2 NPs) are the most commonly used metal oxide NPs in various industrial and commercial products. The present study has demonstrated a significant cellular uptake of TiO2 NPs in the human keratinocyte cells (HaCaT) using transmission electron microscopy and flow cytometry. The data exhibited a significant (p < 0.05...

The exponential growth in the production and consumption of engineered nanoparticles (ENPs) has raised concern about their environmental fate. ENPs accumulation in ecosystems is likely to pose threat to specific and non-specific targets. In this study a novel approach using flow cytometry was validated for detection of ENPs (ZnO and TiO2) uptake in...

Inhibiting Hsp90 chaperone roles using 17AAG induces cytostasis or apoptosis in tumor cells through destabilization of several mutated cancer promoting proteins. Although mitochondria are central in deciding the fate of cells, 17AAG induced effects on tumor cell mitochondria were largely unknown. Here, we show that Hsp90 inhibition with 17AAG first...

We report here on the nuclear penetration capability besides the excellent cellular uptake property of the fluorescent monodisperse mesoporous silica nanospheres (FMMSN) prepared by a bioinspired silicification route. The FMMSNs show great potential as efficient and stable intracellularlabeling agents in human cervical cancer cells and various huma...

A novel Gram-staining-negative, rod shaped, non-motile bacterium, designated strain LW9T, was isolated from a water sample collected at a depth of 4.5 m from Lonar Lake of Buldhana district, Maharastra, India. The cell suspension (broth culture) was reddish-orange due to the presence of carotenoid pigments. Strain LW9T was positive for catalase, or...

We report here on the nuclear penetration capability besides the excellent cellular uptake property of the fluorescent monodisperse mesoporous silica nanospheres (FMMSN) prepared by a bioinspired silicification route. The FMMSNs show great potential as efficient and stable intracellular labeling agents in human cervical cancer cells and various hum...

Herein we demonstrate a simple but versatile bioinspired polyamine-catalyzed silicification route to synthesizing functional materials which is monodisperse, mesoporous, and spherically uniform having nanosizes under extremely mild conditions similar to the biosilicification processes. Employing the principles learned from nature and in particular...

The aggregation behavior of peptides Ac-VQIVYK-amide (AcPHF6) and Ac-QIVYK-amide (AcPHF5) from the amyloidogenic protein tau was examined by atomic force microscopy (AFM) and fluorescence microscopy. Although AcPHF5 did not show enhancement of thioflavin T (ThT) fluorescence in aqueous buffer, distinct aggregates were discernible when peptide was d...

The Mycobacterium tuberculosis genome sequence reveals remarkable absence of many nucleoid-associated proteins (NAPs), such as HNS, Hfq or DPS. In order to characterize the nucleoids of M. tuberculosis, we have attempted to identify NAPs, and report an interesting finding that a chaperonin-homolog, GroEL1, is nucleoid associated. We report that M....

Biphasic calcium phosphate nanoparticles comprising both hydroxyapatite (HA) and beta polymorph of tricalcium phosphate (beta-TCP) have been synthesized together by a polymer matrix mediated process. The process, based on in situ mineralization of poly (vinyl alcohol), exerts a good control over the morphological features of biphasic nanoparticles....

Protein-based nucleic acid carriers offer attractive possibilities to enhance in vitro and in vivo gene delivery to combat diseases. A multi-domain fusion protein, namely TAT-NLS-Mu, designated as TNM, has been designed, cloned, heterologously expressed in E. coli and purified to homogeneity by affinity chromatography. The recombinant chimera TNM h...

Silver impregnated on polymer-titania nanocomposite films exhibit excellent antibacterial properties with the added advantage of repeated use. The polyethylene glycol-polyurethane-titania designated as PEG-PU-TiO2 polymer nanocomposite films were synthesized by simple solution casting technique. Silver has been incorporated into these films by phot...

In a bioinspired methodology, positively charged polypeptides and polyamines directly catalyse ZnO mineralization under "green" conditions of room temperature and neutral pH. The polyamines not only act as mineralizing agents for the formation of ZnO nanoparticles, but also self-assemble the nanoparticles to form spindle-like morphologies at these...

Human β 2 ‐microglobulin (β 2 m) forms amyloid fibrils in hemodialysis related amyloidosis. Peptides spanning the β strands of β 2 m have been shown to form amyloid fibrils in isolation. We have studied the self‐association of a 13‐residue peptide Ac‐DWSFYLLYYTEFT‐am (Pβ 2 m) spanning one of the β‐strands of human β 2 ‐microglobulin when dissolved...

Silver nanoparticles of particle size around 15 nm were synthesized by following a simple and green methodology of photoreduction of silver nitrate (AgNO3) using bare titania and polyvinyl alcohol (PVA)-capped colloidal titanium dioxide nanoparticles/nanotubes under UV−vis light (λ = 365 nm). The synthesized pure TiO2 nanoparticles/tubes, Ag−TiO2 n...

Efforts to clone amyloidogenic proteins in the cells often have resulted in cell death. We report successful cloning and expression of recombinant human islet amyloid polypeptide (hIAPP) in cultured mammalian cells. Amylin gets secreted, forms fibrils that are toxic to target cells like beta cells of rat and human. The study involves cloning of ful...

Generation of novel spontaneous ER positive mammary tumor animal model from heterozygous NIH nude mice. Using brother-sister mating with pedigree expansion system, we derived a colony of heterozygous breeding females showing ER-Positive tumors around the age of 6 months. Complete blood picture, differential leukocyte count, and serum levels of Estr...

The antibacterial activity of peptides without disulfide bridges, spanning the carboxy-terminal segment of arthropod defensins, has been investigated. Although all the peptides have net positive charges, they exhibited varying antibacterial potencies and spectra. Atomic force and fluorescence microscopic analyses indicate that the peptides exert th...

The antibacterial activities of synthetic human beta-defensin analogs, constrained by a single disulfide bridge and in the reduced form, have been investigated. The peptides span the carboxy-terminal region of human beta-defensins (HBD-1-3), which have a majority of cationic residues present in the native defensins. The disulfide constrained peptid...

Acquisition of milk production capabilities by an ancestor of mammals is at the root of mammalian evolution. Milk casein micelles are a primary source of amino acids and calcium phosphate to neonates. To understand the role of κ-casein in lactation, we have created and characterized a null mouse strain (Csnk −/−) lacking this gene. The mutant κ-cas...

To report the clinical outcome of autologous cultivated limbal epithelial transplantation. Eighty-six patients' records and their clinical photographs were reviewed for demographics, primary etiology, type of limbal transplantation, ocular surface stability, visual acuity, final outcome and possible factors affecting outcome and complications. Eigh...

The aim of this investigation was to prepare clonazepam microemulsions (CME) for rapid drug delivery to the brain to treat acute status epileptic patients and to characterize and evaluate the performance of CME in vitro and in vivo in rats. The CME were prepared by the titration method and were characterized for globule size and size distribution,...

The aim of this investigation was to prepare microemulsions containing sumatriptan (ST) and sumatriptan succinate (SS) to accomplish rapid delivery of drug to the brain in acute attacks of migraine and perform comparative in vivo evaluation in rats. Sumatriptan microemulsions (SME)/sumatriptan succinate microemulsions (SSME) were prepared using tit...