Browsing by Author "Remya, NS"

Now showing 1 - 12 of 12
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    A biodegradable in situ injectable hydrogel based on chitosan and oxidized hyaluronic acid for tissue engineering applications
    (CARBOHYDRATE POLYMERS, 2011) Nair, S; Remya, NS; Remya, S; Nair, PD
    An "in situ" biodegradable gel consisting of chitosan, glycerol phosphate (GP) and oxidized hyaluronic acid (HDA) were synthesised and characterized This is a two component hydrogel system where chitosan neutralized with GP resulted in instantaneous gelling when combined with HDA. The gels are cytocompatible and could be freeze dried to form porous scaffolds. The percentage porosity of the freeze-dried chitosan hyaluronic acid dialdehyde gels (CHDA) increased with increasing oxidation. Fibroblast cells seeded onto CHDA porous scaffolds adhered, proliferated and produced ECM components on the scaffold. Chondrocytes encapsulated in CHDA gels retained their viability and specific phenotypic characteristics. The gel material is hence proposed as a scaffold and encapsulating material for tissue engineering applications. (C) 2011 Elsevier Ltd. All rights reserved.
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    An in vitro study on the interaction of hydroxyapatite nanoparticles and bone marrow mesenchymal stem cells for assessing the toxicological behaviour
    (COLLOIDS AND SURFACES B-BIOINTERFACES, 2014) Remya, NS; Syama, S; Gayathri, V; Varma, HK; Mohanan, PV
    Mesenchymal stem cells or multipotent progenitor cells isolated from bone marrow presents close resemblance to the natural in vivo milieu and hence preferred more than the conventional cell culture systems to predict the toxicological behavior of bio-nano interaction. The objective of the present study is to evaluate the molecular toxicity of hydroxyapatite nanoparticles (HANPs) using mouse bone marrow mesenchymal stem cells (BMSCs). In-house synthesized HANPs (50 nm) were used to study the cytotoxicity, nano particle uptake, effect on cyto skeletal arrangement, oxidative stress response and apoptotic behavior with the confluent BMSCs as per standard protocols. The results of the MIT assay indicated that HANPs does not induce cytotoxicity up to 800 mu g/mL. It was also observed that oxidative stress related apoptosis and reactive oxygen species (ROS) production following nanoparticle treatment was similar to that of control (cells without treatment). Hence it can be concluded that the in-house synthesized HANPs are non-toxic/safe at the molecular level suggesting that the HANPs are compatible to BMSCs. Further, the in vitro BMSCs cell culture can be used as a model for evaluating the preliminary toxicity of nanomaterials. (C) 2014 Elsevier B.V. All rights reserved.
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    Biocompatibility of strontium incorporated ceramic coated titanium oxide implant indented for orthopaedic applications
    (Materials Science & Engineering B, 2021-02) Vandana, U; Nancy, D; Sabareeswaran, A; Remya, NS; Rajendran, N; Mohanan, PV
    Titanium and its alloys are the most commonly used materials for manufacturing orthopaedicimplants. Various surface modifications are done in titanium alloys to improve osseointegration as well as for long term success of endosseous implants. In the present study preclinical safety evaluation of two nanoporous mixed metal oxide bone implant materials, TiO2-Nb2O5 (TN) and Sr-HAP modified TN (TNS) were assessed by in vitro and in vivo methods. The surface morphological analysis of fabricated materials was done by XRD, IR and SEM. The biocompatibility evaluations performed were In vitro cytotoxicity tests using L929 cells, Assessment of hemolytic properties of materials and Test for local effects after implantation in bone as per international standards. The results of the study conclude that the materials, TN and TNS are non-cytotoxic, non-hemolytic and biocompatible and can be used safely for orthopaedic applications.
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    Cells-nano interactions and molecular toxicity after delayed hypersensitivity, in Guinea pigs on exposure to hydroxyapatite nanoparticles
    (COLLOIDS AND SURFACES B-BIOINTERFACES, 2013) Geetha, CS; Remya, NS; Leji, KB; Syama, S; Reshma, SC; Sreekanth, PJ; Varma, HK; Mohanan, PV
    The aim of the study was to evaluate the cells-nanoparticle interactions and molecular toxicity after delayed hypersensitivity in Guinea pigs, exposed to hydroxyapatite nanoparticles (HANP). The study focuses on synthesizing and characterizing HANPs and gaining an insight into the cytotoxicity, molecular toxicity, hypersensitivity and oxidative stress caused by them in vitro and in vivo. HANP was synthesized by chemical method and characterized by standard methods. Cytotoxicity was assessed on L929 cells by MTT assay and in vitro studies were carried out on rat liver homogenate. In vivo study was carried out by topical exposure of Guinea pigs with HANP, repeatedly, and evaluating the skin sensitization potential, blood parameters, oxidative stress in liver and brain and DNA damage (8-hydroxyl-2-deoxyguanosine: 8-OHdG) in liver. The results of the study indicated that there was no cytotoxicity (up to 600 mu g/mL) and oxidative damage (up to 100 mu g/mL), when exposed to HANPs. It was also evident that, there was no skin sensitization and oxidative damage when HANP were exposed to Guinea pigs. (C) 2013 Elsevier B.V. All rights reserved.
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    Engineered Nanoparticles with Antimicrobial Property
    (Current Drug Metabolism, 2018-03) Reshma, VG; Syama, S; Sruthi, S; Reshma, SC; Remya, NS; Mohanan, PV
    Abstract: Background: The urge for the development and manufacture of new and effective antimicrobial agents is particularly demanding especially in the present scenario of emerging multiple drug resistant microorganisms. A promising initiative would be to converge nanotechnology to develop novel strategies for antimicrobial treatment. These distinct nano scale properties confer impressive antimicrobial capabilities to nanomaterials that could be exploited. Nanotechnology particularly modulates the physicochemical properties of organic and inorganic nanoparticles, rendering them suitable for various applications related to antimicrobial therapy compared to their bulk counterparts. However, a major issue associated with such usage of nanomaterials is the safety concern on heath care system. Hence, a thorough put knowledge on biocompatible nanostructures intended for antimicrobial therapy is needed. Methods: A systematic review of the existing scientific literature is being attempted here which includes the properties and applications of a few nano structured materials for antimicrobial therapy and also the mechanism of action of nanomaterials as antimicrobial agents. Silver (Ag), Graphene, Quantum dots (QDs), Zinc oxide (ZnO) and chitosan nanoparticles are taken as representatives of metals, semiconductors, metal oxides and organic nanoparticles that have found several applications in antimicrobial therapy are reviewed in detail. Results and Conclusion: An ideal anti microbial should selectively kill or inhibit the growth of microbes but cause little or no adverse effect to the host. Each of the engineered nanomaterials reviewed here has its own advantages and disadvantages. Nanomaterials in general directly disrupt the microbial cell membrane, interact with DNA and proteins or they could indirectly initiate the production of reactive oxygen species (ROS) that damage microbial cell components and viruses. Some like silver nanoparticles have broad spectrum antibacterial activity while others like cadmium containing QDs shows both antibacterial as well as antiprotozoal activity. Nano material formulations can be used directly or as surface coatings or as effective carriers for delivering antibiotics. Polycationic nature of Chitosan NPs helps in conjugation and stabilization of metallic nanoparticles which will enhance their effective usage in antimicrobial therapy.
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    Engineering cartilage tissue interfaces using a natural glycosaminoglycan hydrogel matrix An in vitro study
    (MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS, 2013) Remya, NS; Nair, PD
    Hydrogels are suitable matrices for cartilage tissue engineering on account of their resemblance to native extracellular matrix of articular cartilage and also considering its ease of application, they can be delivered to the defect site in a minimally invasive manner. In this study, we evaluate the suitability of a fast gelling natural biopolymer hydrogel matrix for articular cartilage tissue engineering. A hydrogel based on two natural polymers, chitosan and hyaluronic acid derivative was prepared and physicochemically characterized. Chondrocytes were then encapsulated within the hydrogel and cultured over a period of one month. Cartilage regeneration was assessed by histological, biochemical and gene expression studies. Chondrocytes maintained typical round morphology throughout the course of this investigation, indicating preservation of their phenotype with sufficient production of extracellular matrix and expression of typical chondrogenic markers Collagen type 2 and aggrecan. The results suggest that the natural polymer hydrogel matrix can be used as an efficient matrix for articular cartilage tissue engineering. (C) 2012 Elsevier B.V. All rights reserved.
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    Engineering cartilage tissue interfaces using a natural glycosaminoglycan hydrogel matrix — An in vitro study
    (Materials Science & Engineering C, 2013-01) Remya, NS; Prabha, D. Nair
    Hydrogels are suitable matrices for cartilage tissue engineering on account of their resemblance to native extracellular matrix of articular cartilage and also considering its ease of application, they can be delivered to the defect site in a minimally invasive manner. In this study, we evaluate the suitability of a fast gelling natural biopolymer hydrogel matrix for articular cartilage tissue engineering. A hydrogel based on two natural polymers, chitosan and hyaluronic acid derivative was prepared and physicochemically characterized. Chondrocytes were then encapsulated within the hydrogel and cultured over a period of one month. Cartilage regeneration was assessed by histological, biochemical and gene expression studies. Chondrocytes maintained typical round morphology throughout the course of this investigation, indicating preservation of their phenotype with sufficient production of extracellular matrix and expression of typical chondrogenic markers Collagen type 2 and aggrecan. The results suggest that the natural polymer hydrogel matrix can be used as an efficient matrix for articular cartilage tissue engineering.
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    An in vitro study on the interaction of hydroxyapatite nanoparticles and bone marrow mesenchymal stem cells for assessing the toxicological behavior
    (Colloids Surf B Biointerfaces, 2014-05) Remya, NS; Syama, S; Gayathri, V; Varma, HK; Mohanan, PV
    Mesenchymal stem cells or multipotent progenitor cells isolated from bone marrow presents close resemblance to the natural in vivo milieu and hence preferred more than the conventional cell culture systems to predict the toxicological behavior of bio-nano interaction. The objective of the present study is to evaluate the molecular toxicity of hydroxyapatite nanoparticles (HANPs) using mouse bone marrow mesenchymal stem cells (BMSCs). In-house synthesized HANPs (50 nm) were used to study the cytotoxicity, nano particle uptake, effect on cyto skeletal arrangement, oxidative stress response and apoptotic behavior with the confluent BMSCs as per standard protocols. The results of the MTT assay indicated that HANPs does not induce cytotoxicity up to 800 μg/mL. It was also observed that oxidative stress related apoptosis and reactive oxygen species (ROS) production following nanoparticle treatment was similar to that of control (cells without treatment). Hence it can be concluded that the in-house synthesized HANPs are non-toxic/safe at the molecular level suggesting that the HANPs are compatible to BMSCs. Further, the in vitro BMSCs cell culture can be used as a model for evaluating the preliminary toxicity of nanomaterials.
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    Investigation of chronic toxicity of hydroxyapatite nanoparticles administered orally for one year in wistar rats
    (Materials Science and Engineering, 2017-04) Remya, NS; Syama, S; Sabareeswaran, A; Mohanan, PV
    Although the toxicity/biocompatibility of hydroxyapatite nanoparticles (nano HA), a prospective nano biomaterial is extensively studied, its interaction on biological systems following chronic exposure is less exploited. In the present study, Wistar rats were given various concentrations of nano HA in the diet to determine the chronic toxicity and potential carcinogenicity. Altogether 140 rats were used for the study under various administration dosages along with control. The animals were sacrificed after 12 months of controlled continuous dosing. All in-life parameters, including body weight, food consumption, clinical observations, survival, biochemical and hematology, were unaffected by the chronic exposure of nano HA orally. Similarly, gross and histopathological evaluation was also unchanged following exposure to nano HA. No evidence of nano HA-related lesions or Nano HA-induced neoplasia was suggested in this rodent bioassay study.
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    Preparation and standardization of a batch of Reference Biomaterials (RM) for biological evaluations ( Project - 8169 )
    (SCTIMST, 2020-11-27) Leena, Joseph; Ramesh, P; Remya, NS; Ramesh Babu, V; Anil Kumar, PR; Anugya, Bhatt; Sabareeswaran, A
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    Toxicity, toxicokinetics and biodistribution of dextran stabilized Iron oxide Nanoparticles for biomedical applications
    (International Journal of Pharmaceutics., 2016-08) Remya, NS; Syama, S; Sabareeswaran, A; Mohanan, PV
    Advancement in the field of nanoscience and technology has alarmingly raised the call for comprehending the potential health effects caused by deliberate or unintentional exposure to nanoparticles. Iron oxide magnetic nanoparticles have an increasing number of biomedical applications and hence a complete toxicological profile of the nanomaterial is therefore a mandatory requirement prior to its intended usage to ensure safety and to minimize potential health hazards upon its exposure. The present study elucidates the toxicity of in house synthesized Dextran stabilized iron oxide nanoparticles (DINP) in a regulatory perspective through various routes of exposure, its associated molecular, immune, genotoxic, carcinogenic effects and bio distribution profile. Synthesized ferrite nanomaterials were successfully coated with dextran (<25 nm) and were physicochemically characterized and subjected to in vitro and in vivo toxicity evaluations. The results suggest that surface coating of ferrite nanoparticles with dextran helps in improvising particle stability in biological environments. The nanoparticles do not seem to induce oxidative stress mediated toxicological effects, nor altered physiological process or behavior changes or visible pathological lesions. Furthermore no anticipated health hazards are likely to be associated with the use of DINP and could be concluded that the synthesized DINP is nontoxic/safe to be used for biomedical applications
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    Toxicological evaluation of Imidazole following direct exposure to bone marrow mesenchymal stem cells.
    (Trends Biomater. Artif. Organs., 2014) Reshmitha, TR; Remya, NS; Mohanan, PV