Shantikumar V Nair

Amrita Institute of Medical Sciences and Research Centre, Fort Cochin, Kerala, India

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Publications (150)517.11 Total impact

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    Full-text · Article · Feb 2016 · European Polymer Journal
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    ABSTRACT: Calcium sulfate (CaSO4), an excellent biodegradable bone forming agent that is an ideal choice as additive in gels, however, its disadvantage being poor gel rheology and angiogenesis. Here, we have synthesized chitin-CaSO4-nano-fibrin based injectable gel system which shows improved rheology and angiogenic potential. Rheological studies showed that the composite gel was a shear thinning gel with elastic modulus of 15.4 ± 0.275 kPa; a 1.67 fold increase over chitin control. SEM and XRD analyses revealed the effect of nano-fibrin (nFibrin) in transforming CaSO4 crystal shape from needle to hexagonal. It also masked the retarding effect of CaSO4 towards in vitro early cell attachment and angiogenesis using rabbit adipose derived mesenchymal stem cells (rASCs) and HUVECs, respectively. rASCs osteogenesis was confirmed by spectrophotometric endpoint assay, which showed 6-fold early increase in alkaline phosphatase levels and immuno-cytochemistry analysis. These in vitro results highlight the potential of injectable chitin-CaSO4-nFibrin gel for osteo-regeneration via enhanced angiogenesis.
    No preview · Article · Dec 2015 · Carbohydrate Polymers

  • No preview · Article · Nov 2015
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    G.S. Anjusree · T.G. Deepak · Shantikumar V Nair · A. Sreekumaran Nair
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    ABSTRACT: We report a facile method for the fabrication of TiO2 nanofiber–nanoparticle composite (FP) via. simultaneous electrospraying and electrospinning for dye-sensitized solar cell (DSC) applications. The loading of nanoparticles on the fibers is controlled by varying their feed rates during electrospinning. The FP composites having three different particle loading are prepared by the methodology and the FP with the highest particle loading (denoted as FP-3 in the manuscript) showed the best overall efficiency of 9.15% in comparison to the other compositions of the FP (FP-2, 8.15% and FP-1, 7.51%, respectively) and nanofibers (F) and nanoparticles (P) separately (7.21 and 7.81, respectively). All the material systems are characterized by spectroscopy, microscopy, surface area measurements and the devices are characterized by current–voltage (I-V), incident photon-to-current conversion efficiency (IPCE), electrochemical impedance measurements, etc. I-V, dye-loading and reflectance measurements throw light on the overall performance of the DSC devices.
    Full-text · Article · Nov 2015 · Journal of Energy Chemistry
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    ABSTRACT: A peculiar architecture of one-dimensional MnO2 nanowires was synthesized by an optimized hydrothermal route and has been lucratively exploited to fabricate highly efficient microporous electrode overlays for lithium batteries. These fabricated electrodes comprised of interconnected nanoscale units with wire-shaped profile which exhibits high aspect ratio in the order of 102. Their outstanding intercalation/de-intercalation prerogatives have also been studied to fabricate lithium coin cells which revealed a significant specific capacity and power density of 251 mAh g−1 and 200 W kg−1, respectively. A detailed electrochemical study was performed to elucidate how surface morphology and redox reaction behaviors underlying these electrodes influence the cyclic behavior of the electrode. Rate capability tests at different C-rates were performed to evaluate the capacity and cycling performance of these coin cells.
    No preview · Article · Oct 2015 · Materials Research Bulletin
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    ABSTRACT: The efficacy of protein-vorinostat nanomedicine (NV) is demonstrated in leukemic stem cells (LSC) isolated from refractory acute myeloid leukemia (AML) patient samples, where it successfully ablated both CD34+ CD38– CD123+ LSC and non-LSC “leukemic blast” compartments, without inducing myelosuppression or hemotoxicity. Besides, NV also exerted excellent synergistic lethality against leukemic bone marrow cells (BMC) at lower concentrations (0.1 μM) in combination with DNA methyltransferase (DNMT) inhibitor, decitabine. Considering the extermination of resilient LSC and synergism with decitabine, NV shows promise for clinical translation in the setting of a more tolerable and effective epigenetic targeted therapy for leukemia.
    Full-text · Article · Oct 2015
  • R. S. Surenya · ShantiKumar V. Nair · Vinoth-Kumar Lakshmanan
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    ABSTRACT: Drug delivery is the process of transporting a pharmaceutical compound in the body to achieve therapeutic effect. Drugs can be transported via different routes of administration such as ocular, intranasal, oral, intravenous, intraperitoneal, rectal, subcutaneous etc. Drug delivery depends on the dose and route of administration of the drug. Various drug delivery systems are used to deliver the chemo drugs via different routes. In this review we focused on the nanotechnology based drug delivery systems for the administration of chemo drugs through different routes highlighting the advantages in the therapeutic potentials. Many constrains of conventional drug administration can be overcome by nanoparticulate systems and in future targeted delivery of chemo drugs could be the trust area.
    No preview · Article · Sep 2015
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    ABSTRACT: Pancreatic cancer has an infaust prognosis and is the fourth common cause of cancer related death in India. It is highly resistant to conventional treatment modalities such as chemotherapy, radiation therapy and surgery. The association of pancreatic cancer and diabetes mellitus is explored in our study. Pancreatic cancer is more likely to occur in people who have diabetes than people devoid of it, which is supported by the observation that hyperglycaemia occurs at an early stage of pancreatic cancer and is indeed a risk factor. In the present study, we have demonstrated a synergistic relationship between metformin and boswellic acid nanoparticles with varying doses of boswellic acid nanoparticles and constant metformin (20 mM). The effect revealed increased synergism between metformin and boswellic acid nanoparticles through the inhibition of cell proliferation with an effect of 80% for the combination with 0.3 mg/mL and 0.4 mg/mL and a constant concentration of metformin. We examined the effect of combination on cell migration which revealed time dependent inhibitory effect on pancreatic cell line (MiaPaCa-2). Also, we found that the combinatorial approach significantly decreased colony formation and exhibited high rate of induction of apoptosis through DNA fragmentation in pancreatic cancer cells. In-vitro hemolysis confirmed the hemocompatibility of the combination therapy with metformin and boswellic acid nanoparticles. Flow cytometry based apoptosis assay and Caspase mediated apoptosis proved apoptosis mediated cell death. Further, the cells were analysed with mitochondrial membrane potential kit which revealed depolarization of mitochondrial membrane potential due to apoptosis after treatment with drug combination. Hence, the combination approach proved to be a promising therapy towards pancreatic cancer.
    No preview · Article · Aug 2015 · Journal of Biomedical Nanotechnology
  • John Joseph · Shantikumar V Nair · Deepthy Menon
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    ABSTRACT: The present study describes a unique way of integrating substrate-less electrospinning process with textile technology. We developed a new collector design that provided a pressure-driven, localized cotton-wool structure in free space from which continuous high strength yarns were drawn. An advantage of this integration was that the textile could be drug/dye loaded and be developed into a core-sheath architecture with greater functionality. This method could produce potential nano-textiles for various biomedical applications.
    No preview · Article · Jul 2015 · Nano Letters
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    ABSTRACT: Dye-sensitized solar cells (DSSCs) are considered to be a promising, low-cost alternatives for the amorphous silicon solar cells. The major components of a DSC include a metal oxide (usually TiO2), dye, electrolyte and a Pt- or carbon-deposited counter electrode. The photoexcited electrons from the dyes diffuse through the TiO2 network and reach the counter electrode through an external circuit. However due to the trap-limited diffusion process, the electron collection efficiency is affected. Thus, for a hassale-free transport of electrons there is a need for additional electron transport channels. Further in order to reduce the overall cost of the device there is also a need for cheaper alternative counter electrodes in place of Pt. The 15th most abundant element in the earth’s crust carbon and its allotropes with their outstanding catalytic activity and electrical conductivity proves to be a promising material to overcome all these shortcomings and demerits. The review presented below summarizes the up-to-date research efforts on the role of carbon nanostructures in DSSCs, the various synthetic strategies adopted their preparation and their photovoltaic performance. The review also includes a brief discussion about the role of carbon nanostructures in non-planar flexible wire-shaped DSSCs.
    Full-text · Article · Jul 2015
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    Full-text · Dataset · Jun 2015
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    ABSTRACT: The present study provides detailed experimental results on the synthesis and characterization of carbonized lithium titanate spinel (LTO) composites as electrode materials for lithium ion capacitor. The LTO particles were grafted with a porous carbon layer obtained from the pyrolysis of camphor. The graphitic nature of the carbon was confirmed through Raman spectroscopy. The relative contributions from the capacitive and diffusion controlled processes underlying these electrodes were mathematically modeled. Electron transport mechanism underlying these electrodes was determined by measuring the work functions (φ) of LTO and carbon grafted LTO using ultraviolet photoelectron spectroscopy. These carbon grafted LTO composites exhibited an energy density of 330 mWh·L−1 and a peak power density of 2.8 kW·L−1, when employed as electrodes in coin cells with excellent cycling stability at the end of 4000 cycles.
    No preview · Article · May 2015 · Journal of Energy Chemistry
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    ABSTRACT: The dental follicle is a source of dental follicle stem cells (DFCs), which have the potential to differentiate into the periodontal lineage. DFCs therefore are of value in dental tissue engineering. The purpose of this study was to evaluate the effect of growth factor type and concentration on DFC differentiation into periodontal specific lineages. DFCs were isolated from the human dental follicle and characterized for the expression of mesenchymal markers. The DFCs were positive for CD-73, CD-44 and CD-90; and negative for CD-33, CD-34 and CD-45. The expression of CD-29 and CD-31 was almost negligible. The cells also expressed periodontal ligament and cementum markers such as periodontal ligament associated protein-1 (PLAP-1), fibroblast growth factor-2 (FGF-2) and cementum protein-1 (CEMP-1), however, the expression of osteoblast markers was absent. Further, the DFCs were cultured in three different induction medium to analyze the osteoblastic, fibroblastic and cementoblastic differentiation. RUNX-2, ALP activity, alizarin staining, calcium quantification, collagen Type-1 (Col-1) and osteopontin (OPN) expression confirmed the osteoblastic differentiation of DFCs. DFCs cultured in recombinant human fibroblast growth factor-2 (rhFGF-2) containing medium showed enhanced PLAP-1, FGF-2 and COL-1 expression with increasing concentration of rhFGF-2 confirmed periodontal ligament fibroblastic differentiation. Similarly, DFCs cultured in recombinant human cementum protein-1 (rhCEMP-1) containing medium showed enhanced BSP-2, CEMP-1 and COL-1 expression with respect to rhCEMP-1 confirmed cementoblastic differentiation. The expression of osteoblast, fibroblast and cementoblast related genes of DFCs cultured in induction medium was enhanced in comparison to DFCs cultured in non-induction medium. Thus growth factor dependent differentiation of DFCs into periodontal specific lineages was proved by quantitative analysis.
    Full-text · Article · May 2015 · Tissue Engineering Part C Methods
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    ABSTRACT: Standard in vitro drug testing employs 2-D tissue culture plate systems to test anti-leukemic drugs against cell adhesion-mediated drug-resistant leukemic cells that harbor in 3-D bone marrow microenvironments. This drawback necessitates the fabrication of 3-D scaffolds that have cell adhesion-mediated drug-resistant properties similar to in vivo niches. We therefore aimed at exploiting the known property of polyurethane (PU)/poly-l-lactic acid (PLLA) in forming a micro-nanofibrous structure to fabricate unique, not presented before, as far as we are aware, 3-D micro-nanofibrous scaffold composites using a thermally induced phase separation technique. Among the different combinations of PU/PLLA composites generated, the unique PU/PLLA 60:40 composite displayed micro-nanofibrous morphology similar to decellularized bone marrow with increased protein and fibronectin adsorption. Culturing of acute myeloid leukemia (AML) KG1a cells in FN-coated PU/PLLA 60:40 shows increased cell adhesion and cell adhesion-mediated drug resistance to the drugs cytarabine and daunorubicin without changing the original CD34(+)/CD38(-)/CD33(-) phenotype for 168 hours compared to fibronectin tissue culture plate systems. Molecularly, as seen in vivo, increased chemoresistance is associated with the upregulation of anti-apoptotic Bcl2 and the cell cycle regulatory protein p27(Kip1) leading to cell growth arrest. Abrogation of Bcl2 activity by the Bcl2-specific inhibitor ABT 737 led to cell death in the presence of both cytarabine and daunorubicin, demonstrating that the cell adhesion-mediated drug resistance induced by Bcl2 and p27(Kip1) in the scaffold was similar to that seen in vivo. These results thus show the utility of a platform technology, wherein drug testing can be performed before administering to patients without the necessity for stromal cells.
    Full-text · Article · May 2015 · International Journal of Nanomedicine
  • A Sivashanmugam · R Arunkumar · M Vishnu Priya · Shantikumar V Nair · R Jayakumar
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    ABSTRACT: The desire and need to minimize traditional open surgeries is gearing up as it could reduce the healthcare expenses and improve the recovery time for the patients. Minimal invasive procedures using endoscopes, catheters and needles have been developed considerably in the last few decades. In the field of tissue engineering and regenerative medicine, there is a need for advancement over the conventional scaffolds and pre-formed hydrogels. In this scenario, injectable hydrogels have gained wider appreciation among the researchers, as they can be used in minimally invasive surgical procedures. Injectable gels with their ease of handling, complete filling of the defect area and good permeability have emerged as promising biomaterials. The system can effectively deliver a wide array of therapeutic agents like drugs, growth factors, fillers and even cells. This review provides an overview of the recent trends in the preparation of injectable hydrogels, along with key factors to be kept in balance for designing an effective injectable hydrogel system. Further, we have summarized the application of injectable hydrogels in adipose, bone, cartilage, intervertebral discs and muscle tissue engineering.
    No preview · Article · May 2015 · European Polymer Journal
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    ABSTRACT: Injectable gel systems, for the purpose of bone defect reconstruction has more advantages like controlled flowability, adaptability to the defect site, increased handling properties when compared to the conventionally used autologous graft, scaffolds, hydroxyapatite blocks etc. In this work, nano hydroxyapatite (nHAp) incorporated chitin-poly (ε-caprolactone) (PCL) based injectable composite microgels has been developed by simple regeneration technique for cranial defect repair. The prepared microgels systems were characterized using scanning electron microscope (SEM), Fourier transformed infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). The composite microgel with the incorporation of nHAp, showed an increased elastic modulus, thermal stability and had shear-thinning behavior proving the injectability of the system. The protein adsorption, cytocompatibility and migration of rabbit adipose derived mesenchymal stem cells (rASCs) were also studied. Chitin-PCL-nHAp microgel elicited an early osteogenic differentiation compared to control gel. The immunofluorescence studies confirmed the elevated expression of osteogenic-specific markers such as alkaline phosphatase, osteopontin and osteocalcin in chitin-PCL-nHAp microgels. Thus chitin-PCL-nHAp microgel could be a promising injectable system for regeneration of bone defects which are even in deeper planes, irregularly shaped and complex in nature.
    No preview · Article · Apr 2015 · ACS Applied Materials & Interfaces
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    Sandeep Nandan · T.G. Deepak · Shantikumar V Nair · Sreekumaran Nair
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    ABSTRACT: We synthesized a uniquely shaped one-dimensional (1-D) TiO2 nanostructure having the morphology of yellow bristle grass with high surface area by titanate route under soft reaction conditions. The electrospun TiO2-SiO2 composite nanofibers upon treatment with concentrated NaOH at 80 0C under ambient pressure for 24 h resulted in sodium titanate (Na2Ti3O7) nanostructures. The Na2Ti3O7 nanostructures have an overall 1-D fibrous morphology but the highly porous fiber surfaces were decorated with layered thorn-like features (a morphology resembling that of yellow bristle grass) resulting in high surface area (113 m2/g) and porosity. The Na2Ti3O7 nanostructures were converted into TiO2 nanostructures of the same morphology by acidification (0.1 N HCl) followed by low temperature sintering (110 0C) processes. Dye-sensitized solar cells (DSCs) constructed out of the material (cells of area 0.20 cm2 and thickness of 12 m) showed a power conversion efficiency (η) of 8.02 % in comparison to commercial P-25 TiO2 (η = 6.1 %).
    Full-text · Article · Apr 2015 · Dalton Transactions
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    ABSTRACT: Cancer kinome is now well organized as an important target for a new class of cancer drugs. There are more than 500 members in the kinase family in which some of them are clinically analysed .while the rest are under investigation for potential therapeutic applications. Phosphorylation, major function of kinases is one of the most significant signal transduction mechanism in which intercellular signals regulate intracellular processes like ion transport, hormone responses and cellular proliferation. Any deregulation of kinase function may lead to tumor progression and other disorders such as immunological, neurological , metabolic and including also for the case of infectious diseases. This led to the necessity in the development of kinase inhibitors as therapeutic agent. Herein we discuss about different types of kinases and their inhibitors in various types of cancers. This review portrays a broad overview on the origin of kinases, discovery, characterization and mode of action of kinase inhibitors in cancer therapy.
    No preview · Article · Apr 2015 · Current drug targets
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    ABSTRACT: In this study, graphene oxide (GO) nanoflakes (0.5 and 1 wt%) were incorporated into a gelatin-hydroxyapatite (GHA) matrix through a freeze drying technique and its effect to enhance mechanical strength and osteogenic differentiation was studied. The GHA matrix with GO demonstrated less brittleness in comparison to GHA scaffolds. There was no significant difference in mechanical strength between GOGHA0.5 and GOGHA1.0 scaffolds. When the scaffolds were immersed in phosphate buffered saline (to mimic physiologic condition) for 60 days, around 50-60% of GO was released in sustained and linear manner and the concentration was within the toxicity limit as reported earlier. Further, GOGHA0.5 scaffolds were continued for cell culture experiments, wherein the scaffold induced osteogenic differentiation of human adipose derived mesenchymal stem cells without providing supplements like dexamethasone, L-ascorbic acid and β glycerophosphate in the medium. The level of osteogenic differentiation of stem cells was comparable to those cultured on GHA scaffolds with osteogenic supplements. Thus biocompatible, biodegradable and porous GO reinforced gelatin-HA 3D scaffolds may serve as a suitable candidate in promoting bone regeneration in orthopaedics.
    No preview · Article · Mar 2015 · Nanotechnology
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    ABSTRACT: Stable nano-formulation of Plumbagin nanoparticles from Plumbago zeylanica root extract was explored as a potential natural drug against prostate cancer. Size and morphology analysis by DLS, SEM and AFM revealed the average size of nanoparticles prepared was 100±50nm. In vitro cytotoxicity showed concentration and time dependent toxicity on prostate cancer cells. However, plumbagin crude extract found to be highly toxic to normal cells when compared to plumbagin nanoformulation, thus confirming nano plumbagin shows cytocompatibility with normal cells and dose dependent toxicity to prostate cells. In vitro haemolysis assay confirmed the blood biocompatibility of the plumbagin nanoparticles. In wound healing assay, plumbagin nanoparticles provided clues which might play an important role in the anti-migration of prostate cancer cells. DNA fragmentation revealed that partial apoptosis induction by plumbagin nanoparticles could be expected as a potent anti-cancer agent against prostate cancer.
    No preview · Article · Mar 2015 · Current Drug Delivery

Publication Stats

2k Citations
517.11 Total Impact Points

Institutions

  • 2010-2015
    • Amrita Institute of Medical Sciences and Research Centre
      • Center for Nanosciences and Molecular Medicine
      Fort Cochin, Kerala, India
  • 2009-2015
    • Amrita Vishwa Vidyapeetham
      • Amrita Center for Nanosciences & Molecular Medicine (ACNSMM)
      Koyambattūr, Tamil Nadu, India
  • 2009-2014
    • Amrita Institute of Medical Sciences
      Fort Cochin, Kerala, India
  • 2013
    • National University of Singapore
      Tumasik, Singapore