Browsing by Author "Kumary, TV"

Now showing 1 - 20 of 32
  • Item
    3D printing of liver constructs for in vitro hepatotoxicity testing ( Project - 8141 )
    (SCTIMST, 2021-08-15) Anil Kumar, PR; Shiny, Velayudhan; Roy, Joseph; Kalliyna Krishnan; Kumary, TV; Anugya, Bhatt; Lynda V, Thomas; Sarath S, Nair; Ramesh Babu, V; Sivaram, S; Praveen, KS
  • Item
    A Cytocompatible Poly(N-isopropylacrylamide-co-glycidylmethacrylate) Coated Surface as New Substrate for Corneal Tissue Engineering
    (JOURNAL OF BIOACTIVE AND COMPATIBLE POLYMERS, 2010) Joseph, N; Prasad, T; Raj, V; Kumar, PRA; Sreenivasan, K; Kumary, TV
    The conventional method of retrieving cells for tissue engineering to create three-dimensional functional tissues uses enzymes that may hamper cell viability and re-adhesion. Culturing cells on thermoresponsive surfaces of poly(N-isopropylacrylamide) (PNIPAAm) is a relatively new nondestructive method of creating in vitro tissues. In this study, PNIPAAm and glycidylmethacrylate (GMA)-based thermoresponsive copolymer N-isopropylacrylamide-co-glycidylmethacrylate (NGMA) were synthesized as a potential cell culture harvesting system for generating 3D synthetic tissues. The copolymer was characterized by differential scanning calorimetry, gel permeation chromatography, Fourier transform infrared spectroscopy, water contact angle, atomic force microscopy, and nuclear magnetic resonance spectroscopy. The NGMA-coated dishes were evaluated for cytotoxicity and cytocompatibility using L-929 cells. Primary rabbit corneal cultures established on NGMA surface were detached as an intact cell sheet with epithelial specific characteristics as well as maintenance of cell-cell and cell-extracellular matrix contact. The results confirmed the suitability of NGMA substrate for cell culture and temperature-induced cell sheet harvest. This is the first report on this copolymer formulation as a substrate for tissue engineering application. Hydrophobic GMA apart from modulating the lower critical solution temperature features the prospects of further modification, namely the incorporation of biomolecules through the epoxy groups.
  • Item
    A Novel Design of Wound Dressing Matrix with Electrospun Porous Fibers and Antibiotic Loaded Chitosan Microbeads
    (TISSUE ENGINEERING PART A, 2015) Kumar, PRA; Bhaskaran, A; Krishnan, VSH; Sabareeswaran, A; Haritha, VH; Anie, Y; Kumary, TV
  • Item
    A Novel Thermoresponsive Graft Copolymer Containing Phosphorylated HEMA for Generating Detachable Cell Layers
    (JOURNAL OF APPLIED POLYMER SCIENCE, 2010) Abraham, TN; Raj, V; Prasad, T; Kumar, PRA; Sreenivasan, K; Kumary, TV
    A novel polymeric formulation based on N-isopropylacrylamide (NIPAAm), methylmethacrylate (MMA), and phosphorylated hydroxylethyl methacrylate (Phosp-HEMA) was synthesized and characterized. NIPAAm was copolymerized with a known quantity of MMA to form a poly(NIPAAm-MMA) copolymer and was subsequently grafted with Phosp-HEMA by gamma irradiation to a total dose of 0.5 kGy. The thermoresponsive graft copolymer was characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, contact angle measurements, and energy dispersive X-ray analysis. The cytotoxicity of the graft copolymer analyzed using L-929 fibroblast cells showed noncytotoxic response. The cell adhesion on the graft copolymer was studied using rabbit corneal cells (SIRC) and human osteoblasts (HOS). The adhered cells were found to spread leading to the formation of cell layers. The cell layers with intact cell-cell and cell-extra cellular matrix contact were detached by lowering temperature below the lower critical solution temperature (29 degrees C) of the graft copolymer. The viability and morphology of the cells in detached cell sheets were assessed by live dead staining and environmental scanning electron microscopy, respectively. This interesting feature of cell adhesion to form cell layers and cell sheet retrieval is implicit to be due to the properties of phosphate moieties on thermoresponsive copolymer. To the authors knowledge there is no previous report on phosphate moiety containing thermo responsive polymeric formulations which can modulate cell adhesion and cell sheet retrieval. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 52-62, 2010
  • Item
    Alternate adult stem cells for ocular surface regeneration (Project - 8094)
    (SCTIMST, 2017-10) Kumary, TV; Anil Kumar, PR
  • Item
    Alternate method for grafting thermoresponsive polymer for transferring in vitro cell sheet structures
    (JOURNAL OF APPLIED POLYMER SCIENCE, 2007) Kumar, PRA; Sreenivasan, K; Kumary, TV
    Retrieval of cells for various applications involves enzymatic or mechanical methods that hamper the cell-cell and cell-extracellular matrix (ECM) binding. Poly(N-isopropylacrylamide) (PIPAAm) is a known temperature-sensitive polymer that exhibits a lower critical solution temperature (LCST) around 32 degrees C and is hydrophobic over LCST and hydrophilic below LCST. PIPAAm-grafted culture surface can be used for detaching adhered cells by lowering the temperature below LCST. In this study, polymerization and grafting of PIPPAm was done by gamma (7) ray irradiation instead of the conventional method of electron beam irradiation. The efficacy of the grafted surface was confirmed by the successful growth of different cell lines such as L-929, NRK-49F, HOS, and SIRC. The cell sheet structures with intact cell-cell and cell-ECM contact was detached by lowering incubation temperature below 20 degrees C. Live-dead staining of cells before and after transfer showed that cell sheet structures maintained viability. This approach of synthesizing thermoresponsive surface by gamma-ray irradiation method can be used to culture many other cell types and could be utilized to prepare in vitro tissue constructs for bioengineering. (c) 2007 Wiley Periodicals, Inc.
  • Item
  • Item
    Cell interaction studies with novel Bioglass coated Hydroxyapatite porous blocks
    (Trends in Biomaterials & Artificial Organs., 2006) Nair, MB; Varma, HK; Kumary, TV; Babu, SS; John, A
  • Item
    Cell patch seeding and functional analysis of cellularized scaffolds for tissue engineering
    (BIOMEDICAL MATERIALS, 2007) Kumar, PRA; Varma, HK; Kumary, TV
    Cell seeding has a direct impact on the final structure and function of tissue constructs, especially for applications like tissue engineering and regeneration. In this study seeding cell patches retrieved from the thermoresponsive poly(N-isopropylacrylamide) surface were used to generate in vitro tissue constructs. Porous and dense bone substitute materials were cellularized using osteoblast cells by a patch transfer and a trypsin method. The function and proliferation of cells was analyzed after 7 days of culture. The relative cell growth rate was found to be higher in cellularized porous hydroxyapatite (PHA) than in dense hydroxyapatite. Live-dead staining confirmed viable cells inside the pores of PHA. Increased alkaline phosphatase activity of cells transferred by the cell patch over the trypsin method revealed the significance of cell patch seeding. This novel method of generating tissue constructs by cell patch seeding was successful in cellularizing scaffolds with intact cell function.
  • Item
    Characterisation of novel bioactive glass coated hydroxyapatite granules in correlation with in vitro and in vivo studies
    (Trends in Biomaterials & Artificial Organs., 2006) Sandeep, G; Varma, HK; Kumary, TV; Babu, SS; John, A
  • Item
    Characterization and in vitro evaluation of electrospun chitosan/polycaprolactone blend fibrous mat for skin tissue engineering
    (JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 2015) Prasad, T; Shabeena, EA; Vinod, D; Kumary, TV; Kumar, PRA
    The electrospinning technique allows engineering biomimetic scaffolds within micro to nanoscale range mimicking natural extracellular matrix (ECM). Chitosan (CS) and polycaprolactone (PCL) were dissolved in a modified solvent mixture consisting of formic acid and acetone (3:7) and mixed in different weight ratios to get chitosan-polycaprolactone [CS-PCL] blend solutions. The CS-PCL blend polymer was electrospun in the same solvent system and compared with PCL. The physicochemical characterization of the electrospun fibrous mats was done using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), tensile test, swelling properties, water contact angle (WCA) analysis, surface profilometry and thermo gravimetric analysis (TGA). The CS-PCL fibrous mat showed decreased hydrophobicity. The CS-PCL mats also showed improved swelling property, tensile strength, thermal stability and surface roughness. The cytocompatibility of the CS-PCL and PCL fibrous mats were examined using mouse fibroblast (L-929) cell line by direct contact and cellular activity with extract of materials confirmed non-cytotoxic nature. The potential of CS-PCL and PCL fibrous mats as skin tissue engineering scaffolds were assessed by cell adhesion, viability, proliferation and actin distribution using human keratinocytes (HaCaT) and L-929 cell lines. Results indicate that CSPCL is a better scaffold for attachment and proliferation of keratinocytes and is a potential material for skin tissue engineering.
  • Item
    Characterization of Fibroin and PEG-Blended Fibroin Matrices for In Vitro Adhesion and Proliferation of Osteoblasts
    (JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION, 2009) Acharya, C; Kumary, TV; Ghosh, SK; Kundu, SC
    Silk fibroin protein, isolated from cocoons of the domesticated mulberry silkworm, Bombyx mori, finds extensive application in biomaterial design. In this study, poly(ethylene glycol) (PEG) 4000 has been used for blending fibroin from both B. mori and Antheraea mylitta, the wild tropical non-mulberry silkworm. PEG-blended films have shown marked changes from the pure fibroin films with respect to thermal properties and mechanical properties. FT-IR spectroscopy confirmed incorporation of new functional groups like quinone oximes. Pure fibroin and PEG-blended fibroin films showed biocompatibility with the HOS osteosarcoma cell line. Von Kossa staining confirmed nodule formation due to mineralization and differentiation of osteoblasts on pure and blended matrices. On account of increased surface roughness, higher elongation percentage, higher thermostability and better activity of osteoblasts in terms of intracellular alkaline phosphatase production, PEG-blended A. mylitta fibroin film shows better potential than PEG-blended B. mori fibroin film for use as potential biomaterial. (C) Koninklijke Brill NV, Leiden, 2009
  • Item
    Development of National GLP Guidelines & Identification and selection of National Regulatory Guidelines for Testing and Evaluation of Medical Devices ( Project - 8027 )
    (SCTIMST, 2022-03-31) Mohanan, PV; Muraleedharan, CV; Nagesh, DS; Maya Nandakumar, A; Lissy K, Krishnan; Kumary, TV; Mira, Mohanty; Sreenivasan, K; Bhuvaneshwar, GS
  • Item
    Effect of chronic inflammation and immune response on regeneration induced by decellularized bovine pericardium
    (JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A, 2013) Umashankar, PR; Arun, T; Kumary, TV
    Decellularised tissue produces a variety of host responses ranging from constructive remodeling to scarring on account of its differences in the source of tissue, processing or sterilization methods. In this study, in vivo regeneration induced by decellularised bovine pericardium with or without mild glutaraldehyde crosslinking was studied in relation to its immune and inflammatory response using rat abdominal regeneration model. Mild glutaraldehyde crosslinking was done to subdue inflammatory and immune response without compromising host cell incorporation and graft remodeling. Evaluations were done at both 21 and 90 days. Un-crosslinked decellularised bovine pericardium showed more intense macrophage response predominantly of M2 phenotype at 90 days indicating chronic inflammatory response compared to mildly crosslinked group. This group also showed significant increase in plasma cell and lymphocyte count indicating immune stimulation. Lymphocyte transformation test detected presence of bovine pericardial antigen sensitized lymphocytes at both periods in un-crosslinked group. Lymphocytes from mildly crosslinked group failed to respond in this test at both periods. Significantly higher antibody response was also noted at both periods in un-crosslinked group. However, abdominal wall regeneration was observed only in animals implanted with un-crosslinked decellularised bovine pericardium at 90 days. From the above findings, it is inferred that un-crosslinked decellularised bovine pericardium produced significant chronic inflammatory response at 90 days and stimulated both humoral and cell mediated immune response in comparison to mildly crosslinked decellularised bovine pericardium. Yet this group produced skeletal muscle formation within graft at 90 days. (c) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
  • Item
    Effect of surface-modified superparamagnetic iron oxide nanoparticles (SPIONS) on mast cell infiltration: An acute in vivo study
    (Nanomedicine: Nanotechnology, Biology and Medicine., 2016-07) Sabareeswaran, A; Ansar, EB; Varma, PR; Mohanan, PV; Kumary, TV
    Extensive use of superparamagnetic iron oxide nanoparticles (SPIONS) in theranostics prompted us to investigate the acute changes in cell morphology and function following intravenous administration of surface-modified SPIONS in a rat model. Dextran-coated (DEX) and polyethylene glycol-coated (PEG) SPIONS were synthesized and characterized, and cytocompatibility was evaluated in vitro. Haematological, histopathological, ultrastructural and oxidative stress analyses were carried out 24 h post intravenous administration in vivo. In test groups, SGPT and SGOT enzymes were significantly altered when compared to saline-only controls. Anti-oxidant imbalance and lipid peroxidation were observed in all major organs. Histology revealed iron-laden Kupffer cells and macrophages in liver and lung respectively. Iron overload was observed in the convoluted tubules of the kidney. Mast cell infiltration and distribution were observed differentially in test groups. Although surface modification of SPIONS improved biocompatibility in vitro, they affected anti-oxidant and tissue nitrite levels, which greatly influenced mast cell infiltration in vivo.
  • Item
    Engineering of a polymer layered bio-hybrid heart valve scaffold
    (MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS, 2015) Jahnavi, S; Kumary, TV; Bhuvaneshwar, GS; Natarajan, TS; Verma, RS
    Current treatment strategy for end stage valve disease involves either valvular repair or replacement with homograft/mechanical/bioprosthetic valves. In cases of recurrent stenosis/ regurgitation, valve replacement is preferred choice of treatment over valvular repair. Currently available mechanical valves primarily provide durability whereas bioprosthetic valves have superior tissue compatibility but both lack remodelling and regenerative properties making their utility limited in paediatric patients. With advances in tissue engineering, attempts have been made to fabricate valves with regenerative potential using various polymers, decellularized tissues and hybrid scaffolds. To engineer an ideal heart valve, decellularized bovine pericardium extracellular matrix (DBPECM) is an attractive biocompatible scaffold but has weak mechanical properties and rapid degradation. However, DBPECM can be modified with synthetic polymers to enhance its mechanical properties. In this study, we developed a Bio-Hybrid scaffold with non-cross linked DBPECM in its native structure coated with a layer of Polycaprolactone-Chitosan (PCL-CH) nanofibers that displayed superior mechanical properties. Surface and functional studies demonstrated integration of PCL-CH to the DBPECM with enhanced bio and hemocompatibility. This engineered Bio-Hybrid scaffold exhibited most of the physical, biochemical and functional properties of the native valve that makes it an ideal scaffold for fabrication of cardiac valve with regenerative potential. (C) 2015 Elsevier B.V. All rights reserved.
  • Item
    Evaluation of Polypropylene Hollow-Fiber Prototype Bioreactor for Bioartificial Liver
    (TISSUE ENGINEERING PART A, 2013) Palakkan, AA; Raj, DK; Rojan, J; Raj, RGS; Kumar, PRA; Muraleedharan, CV; Kumary, TV
    Hepatocytes in high density are a requisite for the functional performance of complex devices such as bioartificial liver (BAL). In addition to high cell number, efficient mass transfer is also a key parameter in such devices. High-density culture of cells and efficient mass transfer can be achieved in BAL with hollow-fiber-based bioreactors. Even though different types of hollow fibers have been tried in a BAL, prospects of using polypropylene hollow fibers are not well evaluated. In this study, a prototype of bioreactor with polypropylene hollow fibers was fabricated and evaluated for cytotoxicity and hepatocyte function. High density of HepG2/adult hepatocyte cultures was used to evaluate polypropylene hollow fiber to support the biochemical activities (albumin and urea production), ammonia detoxification, and gene expression and to provide effective oxygenation. The results confirmed that a polypropylene hollow-fiber prototype bioreactor is able to provide efficient oxygenation and supported hepatocyte functions in a high-density culture.
  • Item
  • Item
    Gum arabic-curcumin conjugate micelles with enhanced loading for curcumin delivery to hepatocarcinoma cells
    (CARBOHYDRATE POLYMERS, 2015) Sarika, PR; James, NR; Kumar, PRA; Raj, DK; Kumary, TV
    Curcumin is conjugated to gum arabic, a highly water soluble polysaccharide to enhance the solubility and stability of curcumin. Conjugation of curcumin to gum arabic is confirmed by H-1 NMR, fluorescence and UV spectroscopy studies. The conjugate self assembles to spherical nano-micelles (270 +/- 5 nm) spontaneously, when dispersed in aqueous medium. Spherical morphology of the self assembled conjugate is evidenced by field emission scanning electron microscopy and transmission electron microscopy. The self assembly of the amphiphilic conjugate into micelle in aqueous medium significantly enhances the solubility (900 fold of that of free curcumin) and stability of curcumin in physiological pH. The anticancer activity of the conjugate micelles is found to be higher in human hepatocellular carcinoma (HepG2) cells than in human breast carcinoma (MCF-7) cells. The conjugate exhibits enhanced accumulation and toxicity in HepG2 cells due to the targeting efficiency of the galactose groups present in gum arabic. (C) 2015 Elsevier Ltd. All rights reserved.
  • Item
    In vitro cytocompatibility evaluation of a thermoresponsive NIPAAm-MMA copolymeric surface using L929 cells
    (JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 2010) Varghese, VM; Raj, V; Sreenivasan, K; Kumary, TV
    Scaffold free tissue constructs are preferred in tissue engineering as they overcome all the problems associated with scaffolds. Stimuli responsive polymers enable generation of scaffold free multilayered tissue constructs which would in turn reduce the use of biomaterials in vivo. In this study, we investigated cytocompatibility and thermoresponsiveness of a copolymer of N-Isopropylacrylamide and Methyl Methacrylate. Thermoresponsive surfaces were prepared by coating tissue culture polystyrene with the copolymer solution in isopropanol. Mammalian fibroblast cells (L929 cells) readily adhered on the copolymer. The viability and cellular activity was ensured through Neutral red staining, MTT assay, Tritiated thymidine uptake assay and Immunofluorescent staining for cytoskeletal organisation. Incubation under lower critical solution temperature of copolymer resulted in intact detachment of cells. To conclude, in-house synthesized cytocompatible smart culture substrate intended for tissue engineering was developed using a cost effective and simple technique. Moreover, presence of methyl methacrylate in the copolymer reduced the lower critical solution temperature facilitating extended in vitro manipulation time. As the copolymer is insoluble in water, the copolymer could be polymerised without additional crosslinkers.