Browsing by Author "Thomas, LV"

Now showing 1 - 7 of 7
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    A biodegradable and biocompatible PVA-citric acid polyester with potential applications as matrix for vascular tissue engineering
    (JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 2009) Thomas, LV; Arun, U; Remya, S; Nair, PD
    Unique elastomeric and biocompatible scaffolds were produced by the polyesterification of poly(vinyl alcohol) (PVA) and citric acid via a simple polycondensation reaction. The physicochemical characterization of the materials was done by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), mechanical and surface property analyses. The materials are hydrophilic and have viscoelastic nature. Biodegradable, non-cytotoxic materials that can be tailored into 3D scaffolds could be prepared in an inexpensive manner. This polyester has potential implications in vascular tissue engineering application as a biodegradable elastomeric scaffold.
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    An electrospun citric acid modified polyvinyl alcohol scaffold for vascular tissue engineering
    (Journal of Bioactive and Compatible Polymers, 2019-05) Thomas, LV; Nair, PD
    The main aim of this study is to fabricate an electrospun citric acid modified polyvinyl alcohol polyester that is biodegradable with non-toxic by-products and can be used for the culture of vascular smooth muscle cells. In this study, we have optimized the conditions for the electrospinning process of this polyester. The fibre morphology was studied by scanning electron microscopy which indicated that the fibre diameter was optimum at a range of 200 to 700 µm at 5% concentration and flow rate of 0.3 mL/h. The membranes were characterized for the change in structural aspects at the molecular level. The results showed development of more crystalline domains on electrospinning. The surface characteristics were also explored. Cell culture studies confirmed that the electrospun scaffold supported the attachment and proliferation of smooth muscle cells, which was evident from the cell proliferation assay. Hence, the electrospun polyester scaffolds are non-toxic and biocompatible with vascular smooth muscle cells, and find promising potential as scaffolds for vascular tissue engineering
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    Influence of Mechanical Stimulation in the Development of a Medial Equivalent Tissue-Engineered Vascular Construct using a Gelatin-g-Vinyl Acetate Co-Polymer Scaffold
    (JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION, 2012) Thomas, LV; Nair, PD
    Vascular regeneration in the area of small diameter (<6 mm) vessels via the tissue-engineering approach has been in focus for some time now. In this study, we report the development and evaluation of a tissue-engineered medial equivalent using gelatin-g-vinyl acetate co-polymer (GeVAc) as the scaffold material. GeVAc was synthesized by co-polymerizing gelatin and vinyl acetate monomer in the presence of AIBN as the initiator and subjected to physico-chemical characterization. A porous 3-D scaffold with open interconnected pores was then produced from GeVAc. The scaffold is non-cytotoxic with good smooth muscle cell proliferative capacity and high cell viability. Influence of smooth muscle cell phenotype in response to these scaffolds has been studied under mechanical stimulation. It was found that the cell-seeded tubular GeVAc constructs under mechanical stimulation preferentially supported the contractile phenotype of smooth muscle cells, as evidenced by the elevated expression of contractile protein markers such as alpha-SMA, calponin and SM22 alpha. The mechanical properties and the ECM secretion were also increased on applying the mechanical stimulation. Hence, the results showed the promising potential of the GeVAc scaffolds in the regeneration of the medial equivalent tissue-engineered vascular construct. (C) Koninklijke Brill NV, Leiden, 2011
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    Pulmonary surfactant expression analysis-Role of cell-cell interactions and 3-D tissue-like architecture
    (CELL BIOLOGY INTERNATIONAL, 2015) Nandkumar, MA; Ashna, U; Thomas, LV; Nair, PD
    Surfactant production is important in maintaining alveolar function both in vivo and in vitro, but surfactant expression is the primary property lost by alveolar Type II Pneumocytes in culture and its maintenance is a functional requirement. To develop a functional tissue-like model, the in vivo cell-cell interactions and three dimensional architecture has to be reproduced. To this end, 3D button-shaped synthetic gelatin vinyl acetate (GeVAc) co-polymer scaffold was seeded with different types of lung cells. Functionality of the construct was studied under both static and dynamic conditions. The construct was characterized by Environmental Scanning Electron and fluorescent microscopy, and functionality of the system was analyzed by studying mRNA modulations of all four surfactant genes A, B, C, and D by real time-PCR and varying culture conditions. The scaffold supports alveolar cell adhesion and maintenance of cuboidal morphology, and the alveolar-specific property of surfactant synthesis, which would otherwise be rapidly lost in culture. This is a novel 3D system that expresses all 4 surfactants for a culture duration of 3 weeks.
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    Tissue engineered vascular grafts - Preclinical aspects
    (INTERNATIONAL JOURNAL OF CARDIOLOGY, 2013) Thomas, LV; Lekshmi, V; Nair, PD
    Tissue engineering enables the development of fully biological vascular substitutes that restore, maintain and improve tissue function in a manner identical to natural host tissue. However the development of the appropriate preclinical evaluation techniques for the generation of fully functional tissue-engineered vascular graft (TEVG) is required to establish their safety for use in clinical trials and to test clinical effectiveness. This review gives an insight on the various preclinical studies performed in the area of tissue engineered vascular grafts highlighting the different strategies used with respect to cells and scaffolds, typical animal models used and the major in vivo evaluation studies that have been carried out. The review emphasizes the combined effort of engineers, biologists and clinicians which can take this clinical research to new heights of regenerative therapy. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
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    Tissue engineered vascular graftspreclinical aspects
    (Int. J Cardiol., 2012-10) Thomas, LV; Lekshmi, V; Nair, PD
    Tissue engineering enables the development of fully biological vascular substitutes that restore, maintain and improve tissue function in a manner identical to natural host tissue. However the development of the appropriate preclinical evaluation techniques for the generation of fully functional tissue-engineered vascular graft (TEVG) is required to establish their safety for use in clinical trials and to test clinical effectiveness. This review gives an insight on the various preclinical studies performed in the area of tissue engineered vascular grafts highlighting the different strategies used with respect to cells and scaffolds, typical animal models used and the major in vivo evaluation studies that have been carried out. The review emphasizes the combined effort of engineers, biologists and clinicians which can take this clinical research to new heights of regenerative therapy.