Browsing by Author "Anilkumar, TV"

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    Advantages of hyaluronic acid as a component of fibrin sheet for care of acute wound
    (BIOLOGICALS, 2011)
    Skin injury is followed by accumulation of a fibrin based provisional matrix which normally drives the process of wound repair. Exogenous fibrin with extra cellular matrix (ECM) components can also favor the wound healing process. In a preliminary study we found that lyophilized fibrin sheet (FS) arrest bleeding from rabbit skin wound but it remained dry during the repair period and did not accelerate the healing process better than untreated control. In the current study, hyaluronic acid (HA) was incorporated into FS and the resultant HA-FS promoted water retention and improved wound healing process. Gross-morphology, histopathology and histomorphometry were employed to compare qualitative and quantitative difference of wound healing in treated group against controls. In experimental sites (HA-FS), re-epithelialization was completed by 14 days with neo-vascularization and deposition of wavy bundles of collagen in the treated sites. Rate of healing process was different in treated and untreated wounds and most striking difference was the appearance of appendages, sebaceous gland and hair follicle at some locations in HA-FS treated sites. Therefore, HA with fibrin can create an effective wound care matrix which promotes water retention and wound healing potential. (C) 2011 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.
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    Amphotericin B-gum arabic conjugates: Synthesis, toxicity, bioavailability, and activities against Leishmania and fungi
    (PHARMACEUTICAL RESEARCH, 2007)
    Purpose. Gum arabic, a branched polysaccharide consisting of more than 90% arabinogalactan having a molecular weight around 250,000 Da is the oldest and best known of all natural gums. The objective of the present investigation was to examine whether amphotericin B (AmB), the polyene antibiotic when conjugated to periodate oxidized gum arabic still retained its anti-fungal and anti-leishmanial activity and to evaluate its toxicity and bioavailability.Methods. AmB conjugated to the oxidized polysaccharide through Schiff's linkages in the unreduced (imine) and reduced (amine) forms were characterized for the drug content, hemolytic potential, molecular mass, in vitro release and were examined for anti-fungal activity against Candida albicans and Cryptococcus neoformans and for anti-leishmanial activity against promastigotes of Leishmania donovani in culture. Toxicity and bioavailability were evaluated by intravenous (i.v) injections of the conjugates in mice and rabbits respectively.Results. The conjugates were found to be non-hemolytic and mice withstood a dosage of 20 mg (AmB)/kg body weight of both conjugates. Histological examination of the internal organs of mice showed no lesions in kidney, brain, heart or liver. Estimation of the residual drug in the internal organs 7 days post injection showed that the spleen still retained 8.4 +/- 0.53 mu g/g of tissue. AmB was found to be released from both conjugates in vitro although the release from the imine conjugate was much faster than from the amine conjugate. The concentrations inhibiting parasite growth by 50% (IC50) values for the imine conjugate against promastigotes of L. donovani LV9 and DD8 strains were 0.37 +/- 0.04 and 1.44 +/- 0.18 mu M respectively. The IC50 values for the amine conjugates were much higher. The minimum inhibitory concentration (MIC) against C. albicans and C. neoformans was in the range of 0.5-0.9 mu g/mL for both imino and amino conjugates. The bioavailability of the conjugate in rabbits showed that the imine conjugate maintained a plasma concentration in the range of 20 to 5 mu g/mL while for the amine conjugate it was in the range of 17 to 3 mu g/mL over 24 h.Conclusions. The drug conjugates were stable, non-hemolytic and non-toxic to the internal organs of the animal and showed good anti-fungal and anti-leishmanial activity in vitro. In spite of the large molecular weight of the polysaccharide, AmB from the conjugates showed bioavailability after i.v injection. Since the highest concentration of AmB was found in the spleen after a single injection, these conjugates may have potential in anti-leishmanial therapy.
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    Astaxanthin modulates osteopontin and transforming growth factor beta 1 expression levels in a rat model of nephrolithiasis: a comparison with citrate administration
    (BJU INTERNATIONAL, 2014) Alex, M; Paul, MVS; Abhilash, M; Mathews, VV; Anilkumar, TV; Nair, RH
    Objectives To evaluate the effect of astaxanthin on renal angiotensin-I converting enzyme (ACE) levels, osteopontin (OPN) and transforming growth factor beta 1 (TGF-beta 1) expressions and the extent of crystal deposition in experimentally induced calcium oxalate kidney stone disease in a male Wistar rat model. To compare the efficacy of astaxanthin treatment with a currently used treatment strategy (citrate administration) for kidney stones. Materials and Methods The expression of OPN was assessed by immunohistochemistry. One step reverse transcriptase polymerase chain reaction followed by densitometry was used to assess renal OPN and TGF-beta 1 levels. Renal ACE levels were quantified by an enzyme-linked immunosorbent assay method. Crystal deposition in kidney was analysed by scanning electron microscopic (SEM)-energy-dispersive X-ray (EDX). Results The renal ACE levels and the expression of OPN and TGF-beta 1 were upregulated in the nephrolithiasis-induced rats. Astaxanthin treatment reduced renal ACE levels and the expression OPN and TGF-beta 1. SEM-EDX analysis showed that crystal deposition was reduced in the astaxanthin-treated nephrolithiatic group. Astaxanthin treatment was more effective than citrate administration in the regulation of renal ACE levels, OPN and TGF-beta 1 expressions. Conclusions Astaxanthin administration reduced renal calcium oxalate crystal deposition possibly by modulating the renal renin-angiotensin system (RAS), which reduced the expression of OPN and TGF-beta 1 levels. Astaxanthin administration was more effective than citrate treatment in reducing crystal deposition and down-regulating the expression of OPN and TGF-beta 1.
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    Biocompatibility and 1.923 Immunophenotypic Characterization of a Porcine Cholecyst-derived Scaffold Implanted in Rats
    (Toxicol Pathol., 2015-02) Muhamed, J; Revi, D; Rajan, A; Geetha, S; Anilkumar, TV
    Comparative histomorphological assessment of local response to implanted reference biomaterial, also called biocompatibility testing/evaluation, in an appropriate animal model is a widely practiced safety evaluation procedure performed on biomaterials before clinical use. Standardized protocols and procedures, originally designed for testing synthetic materials, available for the testing/evaluation do not account for the immunogenic potential of a candidate biomaterial. Therefore, it is appropriate to supplement the routine biocompatibility test reports with adjunct data that may provide insight into the immunogenic potential of candidate biomaterials, especially when testing biomaterials that are derived from mammalian sources. This article presents expanded safety evaluation data of a porcine cholecyst–derived scaffold (CDS) intended as a xenogeneic graft. The biocompatibility was tested in rat subcutaneous model in comparison with a reference material and the CDS was found biocompatible. However, when studied by immunohistochemistry and real-time reverse transcription polymerase chain reaction for the number and/or polarization of M1 macrophage, M2 macrophage, cytotoxic T-cell, helper T cell, TH1 cell, and TH2 cell, the CDS appeared to induce a differential local immunopathological tissue reaction despite the similarity in biocompatibility with the reference material. The adjunct data collected were useful for objectively assessing the safety of CDS as a xenograft.
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    Biocompatibility and Immunophenotypic Characterization of a Porcine Cholecyst-derived Scaffold Implanted in Rats
    (TOXICOLOGIC PATHOLOGY, 2015) Muhamed, J; Revi, D; Rajan, A; Geetha, S; Anilkumar, TV
    Comparative histomorphological assessment of local response to implanted reference biomaterial, also called biocompatibility testing/evaluation, in an appropriate animal model is a widely practiced safety evaluation procedure performed on biomaterials before clinical use. Standardized protocols and procedures, originally designed for testing synthetic materials, available for the testing/evaluation do not account for the immunogenic potential of a candidate biomaterial. Therefore, it is appropriate to supplement the routine biocompatibility test reports with adjunct data that may provide insight into the immunogenic potential of candidate biomaterials, especially when testing biomaterials that are derived from mammalian sources. This article presents expanded safety evaluation data of a porcine cholecyst-derived scaffold (CDS) intended as a xenogeneic graft. The biocompatibility was tested in rat subcutaneous model in comparison with a reference material and the CDS was found biocompatible. However, when studied by immunohistochemistry and real-time reverse transcription polymerase chain reaction for the number and/or polarization of M1 macrophage, M2 macrophage, cytotoxic T-cell, helper T cell, TH1 cell, and TH2 cell, the CDS appeared to induce a differential local immunopathological tissue reaction despite the similarity in biocompatibility with the reference material. The adjunct data collected were useful for objectively assessing the safety of CDS as a xenograft.
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    Biomaterial properties of cholecyst-derived scaffold recovered by a non-detergent/enzymatic method
    (JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS, 2014) Anilkumar, TV; Vineetha, VP; Revi, D; Muhamed, J; Rajan, A
    Isolation procedures for the recovery of extracellular matrices (ECMs) from animal organs/tissues that are useful in regenerative medicine involve multiple sequential steps/stages including collection of the source organ at slaughter, their transportation to laboratory, decellularization, decontamination, stabilization, and sterilization. Most of these steps require extensive use of chemicals/reagents/enzymes which may also adversely affect the quality of the scaffold. With an effort to minimize the use of chemicals/reagents/enzymes, while extracting biomaterial-grade ECM from porcine cholecyst (gall bladder), we performed preisolation ex situ incubation of the organ in a stabilizing agent that also caused in situ crosslinking of tissue-components and delaminated the collagen-rich ECM from the tissue-layer beneath the mucosa. The physical, chemical, and biological properties of the isolated scaffolds were similar to that of a commercially available porcine small intestinal submucosa. The cholecyst-derived scaffold not only satisfied preclinical safety-test procedures such as cytotoxicity, local response, and endotoxin load but also showed the potential to promote healing of full-thickness skin wound in a rabbit model. The procedure was also suitable for isolating scaffolds from other hollow organs such as jejunum and urinary bladder. It was concluded that enzyme/detergent treatment may be an avoidable step while isolating biomaterial-grade scaffolds from hollow organs. (C) 2014 Wiley Periodicals, Inc.
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    Chitosan scaffold co-cultured with keratinocyte and fibroblast heals full thickness skin wounds in rabbit
    (JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A, 2014) Revi, D; Paul, W; Anilkumar, TV; Sharma, CP
    This study evaluated the modulatory effect of chitosan sponge co-cultured with keratinocyte and fibroblast on wound healing. Dermal fibroblasts and keratinocyte isolated from rabbit skin were co-cultured on chitosan sponge, to fabricate cell-loaded chitosan tissue engineered construct. Full thickness excision wounds created on the rabbit dorsum were treated with three types of graft materials - a noncellular chitosan graft, homologous keratinocyte fibroblast loaded chitosan, and a commercial product. Postgraft skin-wound samples were examined histomorphologically at 7th, 14th, and 28th day after staining with hematoxylin and eosin, picrosirius red and/or immunohistochemistry. Wound healing parameters considered were the extent of re-epithelialization, collagen deposition, and neoangiogenesis. The number of proliferating cells, vimentin positive cells, and alpha smooth muscle actin cells were also quantified. The histology results suggested that the grafts aided wound healing but, the cell-loaded graft induced a differential pattern of healing and had lower scarring tendency. The cell-loaded tissue construct may be useful as a therapeutic graft for treating wounds where there is a total loss of tissue and cells as in burn injury. (C) 2013 Wiley Periodicals, Inc.
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    Chitosan/alginate based antioxidant polymeric wound dressings for controlled antibiotic delivery ( Project - 8143 )
    (SCTIMST, 2020-06-20) Rekha, MR; Anilkumar, TV; Maya Nandakumar, A; Harikrishna, VS
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    A cholecystic extracellular matrix-based hybrid hydrogel for skeletal muscle tissue engineering
    (Journal of Biomedical Materials Research, 2020-05) Raj, R; Sobhan, PK; Kanakarajan, V; Pratheesh, KV; Anilkumar, TV
    Tailoring the properties of extracellular matrix (ECM) based hydrogels by conjugating with synthetic polymers is an emerging method for designing hybridhydrogels for a wide range of tissue engineering applications. In this study, poly(ethylene glycol) diacrylate (PEGDA), a synthetic polymer at variable concentrations (ranging from 0.2 to 2% wt/vol) was conjugated with porcine cholecyst derived ECM (C-ECM) (1% wt/vol) and prepared a biosynthetic hydrogel having enhanced physico-mechanical properties, as required for skeletal muscle tissue engineering. The C-ECM was functionalized with acrylate groups using activated N-hydroxysuccinimide ester-based chemistry and then conjugated with PEGDA via free-radical polymerization in presence of ammonium persulfate and ascorbic acid. The physicochemical characteristics of the hydrogels were evaluated by Fourier transform infrared spectroscopy and environmental scanning electron microscopy. Further, the hydrogel properties were studied by evaluating rheology, swelling, gelation time, percentage gel fraction, in vitro degradation, and mechanical strength. Biocompatibility of the gel formulations were assessed using the C2C12 skeletal myoblast cells. The hydrogel formulations containing 0.2 and 0.5% wt/vol of PEGDA were non-cytotoxic and found suitable for growth and proliferation of skeletal myoblasts. The study demonstrated a method for modulating the properties of ECM hydrogels through conjugation with bio-inert polymers for skeletal muscle tissue engineering applications.
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    Comparative cytomorphometric analysis of oral mucosal cells in normal, tobacco users, oral leukoplakia and oral squamous cell carcinoma
    (JOURNAL OF CYTOLOGY, 2015) Nivia, M; Sunil, SN; Rathy, R; Anilkumar, TV
    Background: Squamous cell carcinoma (SCC) is the third most common cause of oral morbidity in India despite the numerous advances made in the treatment protocol. Aim: To compare the cytomorphometric changes of oral mucosal cells in normal subjects (Group I) with that of tobacco users without any lesion (Group II), tobacco users with oral leukoplakia (Group III), and tobacco users with oral SCC (Group IV) through a semi-automated image analysis system. Materials and Methods: Oral mucosal cells collected from study subjects (n = 100) stained using rapid Papanicolaou stain. Photomicrograph of 50 nonoverlapping cells captured at 50x magnification with a digital image capture system. Cytomorphometric analysis of cells in the captured images was performed with Image-Pro image analysis software. Image analysis was performed to obtain cell diameter (CD), cytoplasmic area (CyA), nuclear diameter (ND), nuclear area (NA), and nuclear-to-cytoplasmic ratio. These values were statistically compared among the groups using one-way analysis of variance (ANOVA) and Mann-Whitney U test. Results: The ND, NA, and nuclear-to-cytoplasmic ratio values were found to be increased in the samples collected from leukoplakia and oral SCC. The CD and CyA decreased compared to the normal mucosa in oral SCC samples. Conclusion: The cytomorphometric changes observed in samples from oral SCC and oral leukoplakia were consistent with the current diagnostic features. Hence, the semi-automated cytomorphometric analysis of oral mucosal cells can be used as an objective adjunct diagnostic tool in the diagnosis of these lesions.
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    Comparative local immunogenic potential of scaffolds prepared from porcine cholecyst, jejunum, and urinary bladder in rat subcutaneous model
    (JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS, 2015) Muhamed, J; Revi, D; Rajan, A; Anilkumar, TV
    Extracellular matrices isolated from several mammalian organs/tissues have found several clinical uses as xenografts or implants. However, they may cause complications because of adverse immunologic reactions. Scaffolds that promote favorable graft-acceptance reaction are preferred for fabricating xenografts. The objective of this study was to evaluate the immunogenic potential of a porcine cholecyst-derived scaffold (CDS), prepared by a non-detergent/enzymatic method, in comparison with jejunum and urinary bladder-derived scaffolds in a rat subcutaneous model. Key graft-rejection/acceptance reaction was evaluated at the site of implantation by studying the occurrence and/or function of immunocompetent cells in the tissue reaction. There was differential occurrence of M1-macrophage, M2-macrophage, T-helper cells, T-cytotoxic cells, B-cells, and mast cells in the tissue reaction and the CDS attracted few cells compared with other scaffolds. Real-time polymerase chain reaction for evaluating mRNA of functional markers like inducible nitric oxide synthase (M1 macrophage), arginase 1 (M2 macrophage), interferon gamma (TH1 lymphocytes), and interlukin-4 (TH2 lymphocytes) suggested that the CDS, compared with the scaffolds prepared from small intestine and urinary bladder, elicited M2 macrophage and TH2 lymphocyte polarization that are congenial graft-acceptance reactions. The results indicated that CDS has less immunogenic potential compared with the scaffolds prepared from jejunum and urinary bladder when used as subcutaneous graft in rats. It was concluded that CDS is a promising animal-derived xenograft for biomedical application. (c) 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1302-1311, 2015.
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    Controlled cross-linking of porcine cholecyst extracellular matrix for preparing tissue engineering scaffold. Biomed Mater Res. part B
    (Applied Biomaterials, 2019-08) Mony, MP; Anilkumar, TV
    Treatment with cross‐linking agents for stabilizing biomolecules is an integral step during the preparation of many extracellular matrix‐based tissue engineering scaffolds from mammalian organs. However, excess cross‐linking may cause nonavailability of biomolecules and consequent deterioration of bioinductive properties of the scaffold. The present study considered controlling the extent of cross‐linking in a porcine cholecyst extracellular matrix scaffold prepared by a nonenzymatic and nondetergent method, by ex situ incubation of the source organ in varying concentrations of neutral buffered formaldehyde (10, 4, 1 or 0%; v/v) for in situ cross‐linking of biomolecules. Reduction of the formaldehyde concentration resulted in an increase in the extent of biodegradation and a decrease in the compactness of the mesh‐like surface microarchitecture of the scaffold. Retention of collagen was maximum when treated with 10% neutral buffered formaldehyde without any variation in the content of elastin and sulphated glycosaminoglycans. Although there was a reduction in the quantity of growth factors following the cross‐linking, fibroblasts remained viable on the scaffolds. The retention of major biomolecule was maximum and autodigestion was minimum in the scaffold prepared by the ex situ treatment of cholecyst in 10% neutral buffered formalin and found suitable for preparing the tissue engineering scaffold.
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    Differential Healing of Full Thickness Rabbit Skin Wound by Fibroblast Loaded Chitosan Sponge
    (JOURNAL OF BIOMATERIALS AND TISSUE ENGINEERING, 2013) Deepa, R; Paul, W; Anilkumar, TV; Sharma, CP
    For fabricating skin grafts with differential healing properties, enrichment with biomolecules/cells may be desirable. Earlier, we have developed a biomaterial-quality chitosan for biomedical application. Here we evaluated the wound healing potential of the chitosan-preparation and its variant, prepared by loading homologus fibroblast. Dermal fibroblasts isolated from rabbit skin were seeded on chitosan sponge to fabricate a homologous fibroblast loaded chitosan graft (HFLC). Full thickness excision wounds created on the rabbit dorsum were grafted with these two types of the chitosan sponges; naked or non cellular chitosan graft (NCC) and the homologous fibroblast loaded chitosan graft (HFLC). Post-graft skin-wound samples were examined histomorphologically at 7th, 14th and 21st day for evaluating the nature of the tissue reaction induced by the grafts. The wound healing parameters considered were the extent of re-epithelialisation, collagen deposition and angiogenesis, the thickness of epidermis, number of proliferating cells, vimentin positive cells and alpha smooth muscle actin cells. The results suggested that both the grafts aided wound healing but the HFLC induced a differential pattern of healing at 7 and 14 days featured by enhanced angiogenesis, desmoplasia and a hyperkeratotic dermis. Under therapeutic conditions, the HFLC may be useful for regulating the extent of collagen deposition in the early phases of a healing wound.
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    Fibroblast-loaded cholecyst-derived scaffold induces faster healing of full thickness burn wound in rabbit
    (JOURNAL OF BIOMATERIALS APPLICATIONS, 2016) Revi, D; Geetha, C; Thekkuveettil, A; Anilkumar, TV
    Graft-assisted healing is often proposed for clinical management of large-sized third-degree cutaneous burn wounds. Skin-graft substitutes prepared by loading appropriate cell types on suitable scaffolds have been found successful. We have previously shown that cholecyst-derived scaffold prepared by a non-detergent/enzymatic method can be used as skin-graft substitute for promoting healing of full thickness excision wounds in rabbit. This article examines the use of this scaffold for preparing bio-artificial grafts by loading homologous fibroblasts. The healing potential was evaluated in a rabbit model of full thickness skin-burn wound. The healing process was evaluated by gross morphology evaluation and histomorphology evaluation at 7, 14 and 28 days of healing. Ex vivo imaging of the wounded tissue was performed and it was found that the loaded fibroblasts remained viable at least for 14 days in the healing wound. By the first week, re-epithelialisation was evident in all animals treated with the cell-loaded graft. Histomorphological wound healing parameters such as the quickness of re-epithelialisation, the nature of collagen deposition and the extent of neo-vascularisation indicated that cell-loaded grafts promoted faster healing of the wounds. Results of immunohistochemistry indicated a parallel change in the number of proliferating cells and myofibroblast in the healing tissue. Although the pathophysiology of the healing reaction was not established, the observations suggested that homologus fibroblast-loaded cholecyst-derived scaffold promoted faster healing of third-degree wounds in rabbit model by modulating myofibroblast response. It was concluded that cholecyst-derived scaffold prepared by the non-detergent/enzymatic method is a potential scaffold for fabricating bioartificial skin grafts.
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    Flexible and Microporous Chitosan Hydrogel/Nano ZnO Composite Bandages for Wound Dressing: In Vitro and In Vivo Evaluation
    (ACS APPLIED MATERIALS & INTERFACES, 2012) Kumar, PTS; Lakshmanan, VK; Anilkumar, TV; Ramya, C; Reshmi, P; Unnikrishnan, AG; Nair, SV; Jayakumar, R
    Current wound dressings have disadvantages such as less flexibility, poor mechanical strength, lack of porosity, and a tendency for dressings to adhere onto the wound surface; in addition, a majority of the dressings did not possess antibacterial activity. Hydrogel-based wound dressings would be helpful to provide a cooling sensation and a moisture environment, as well as act as a barrier to microbes. To overcome these hassles, we have developed flexible and microporous chitosan hydrogel/nano zinc oxide composite bandages (CZBs) via the incorporation of zinc oxide nanoparticles (nZnO) into chitosan hydrogel. The prepared nanocomposite bandages were characterized using transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), and scanning electron microscopy (SEM). In addition, swelling, degradation, blood clotting, antibacterial, cytocompatibility, cell attachment on the material, and cell infiltration into the composite bandages were evaluated. The nanocomposite bandage showed enhanced swelling, blood clotting, and antibacterial activity. Cytocompatibility of the composite bandage has been analyzed in normal human dermal fibroblast cells. Cell attachment and infiltration studies showed that the cells were found attached to the nanocomposite bandages and penetrated into the interior. Furthermore, the in vivo evaluations in Sprague-Dawley rats revealed that these nanocomposite bandages enhanced the wound healing and helped for faster re-epithelialization and collagen deposition. The obtained data strongly encourage the use of these composite bandages for burn wounds, chronic wounds, and diabetic foot ulcers.
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    A gold nano particle coated porcine cholecyst-derived bio scaffold for cardiac tissue engineering
    (Colloids and surfaces: B Biointerfaces, 2017-06) Nair, RS; Ameer, JM; Alison, MR; Anilkumar, TV
    Extracellular matrices of xenogeneic origin have been extensively used for biomedical applications, despite the possibility of heterogeneity in structure. Surface modification of biologically derived biomaterials using nanoparticles is an emerging strategy for improving topographical homogeneity when employing these scaffolds for sophisticated tissue engineering applications.Recently, as a tissue engineering scaffold, cholecyst derived extracellular matrix (C-ECM) has been shown to have several advantages over extracellular matrices derived from other organs such as jejunum and urinary bladder. This study explored the possibility of adding gold nanoparticles, which have a large surface area to volume ratio on C-ECM for achieving homogeneity in surface architecture, a requirement for cardiac tissue engineering. In the current study, gold nanoparticles (AuNPs) were synthesized and functionalised for conjugating with a porcine cholecystic extracellular matrix scaffold. The conjugation of nanoparticles to C-ECM was achieved by 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide/N-hydroxysuccinimide chemistry and further characterized by Fourier transform infrared spectroscopy, environmental scanning electron microscopy, energy dispersive X-ray spectroscopy and thermogravimetric analysis. The physical properties of the modified scaffold were similar to the original C-ECM. Biological properties were evaluated by using H9c2 cells, a cardiomyoblast cell line commonly used for cellular and molecular studies of cardiac cells. The modified scaffold was found to be a suitable substrate for the growth and proliferation of the cardiomyoblasts. Further, the non-cytotoxic nature of the modified scaffold was established by direct contact cytotoxicity testing and live/dead staining. Thus, the modified C-ECM appears to be a potential biomaterial for cardiac tissue engineering.
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    Increased sensitivity of BRCA defective triple negative breast tumors to plumbagin through induction of DNA Double Strand Breaks (DSB)
    (SCIENTIFIC REPORTS, 2016) Nair, RS; Kumar, JM; Jose, J; Somasundaram, V; Hemalatha, SK; Sengodan, SK; Nadhan, R; Anilkumar, TV; Srinivas, P
    We have earlier shown that Plumbagin (PB) can induce selective cytotoxicity to BRCA1 defective ovarian cancer cells; however, the effect of this molecule in BRCA1 mutated breast cancers has not been analyzed yet. Here, we report that reactive oxygen species (ROS) induced by PB resulted in DNA DSB and activates downstream signaling by ATR/ATM kinases and subsequent apoptosis. PB reduces DNA-dependent protein kinase (DNA-PK) expression and inhibits NHEJ (Non Homologous End Joining) activity in BRCA1 defective breast cancer cells. Also, PB induces apoptosis in two different BRCA1 conditional knock out murine models: MMTV-Cre; BRCA1(Co/Co) and WAP-Cre; BRCA1(Co/Co), at 2 mg/kg body weight, but 32 mg/kg of carboplatin (CN) was needed to induce apoptosis in them. This is the first study where two different tissue specific promoter driven transgenic mice models with BRCA1 exon 11 deletions are used for preclinical drug testing. The apoptosis induced by PB in HR (Homologous Recombination) defective triple negative BRCA1 mutant cell lines and in mouse models occur by inducing ROS mediated DNA DSB. The toxicity profile as compared with CN in transgenic mice provides evidence for PB's safer disposition as a therapeutic lead in breast cancer drug development.
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    Long term tissue response to titanium coated with diamond like carbon
    (BIOMOLECULAR ENGINEERING, 2002)
    Diamond like carbon (DLC) coatings were deposited on to Ti substrates by plasma enhanced chemical vapor deposition technique. Ti and DLC/Ti samples were implanted in skeletal muscle of rabbits. The samples were explanted after 1, 3, 6 and 12 months and the tissue-cell interaction was studied. Our data indicate both DLC/Ti and bare Ti to be compatible with skeletal muscle. (C) 2002 Elsevier Science B.V. All rights reserved.
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    Preparation and characterization of cholecystic extracellular matrix powder forms for biomedical applications
    (Biomedical physics and engineering express, 2018-07) Raj, R; Anilkumar, TV; Rajan, A
    Biological scaffold materials derived from extracellular matrices (ECM) of mammalian organs and tissues have been extensively used in various clinical applications. Thin sheets of cholecystic extracellular matrix (C-ECM) have been used for tissue engineering applications like graft-assisted wound healing. However, the use of two dimensional forms of any ECM-based biomaterials has inherent limitations with regard to three dimensional shape/form and clinical utility. On the other hand, powder form of ECM provides a great deal more flexibility in terms of delivery of the biomaterial to the target sites. Considering this, two candidate C-ECM powder forms were prepared by conventional freeze milling either with or without salt precipitation and biomaterial properties were evaluated. Biomaterial properties of these powder forms were analyzed by Differential light scattering, Environmental scanning electron microscopy, Fourier transform infrared spectroscopy and x-ray diffraction. Selected biomolecular contents were estimated in these powder forms in addition to their cytotoxicity potential. The powder form prepared by salt precipitation method resulted in particles with low particle size (344.5 ± 1.61 nm) appropriate for a clinical form. It retained the major biomolecular composition of the C-ECM and did not cause cytotoxicity to L-929 cells. The study identified salt precipitation method for preparing particulate form of C-ECM that retained the original biomolecular composition.