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Danny CG, Manoharan K, Kumar NA, Sowbaghya PT. Unveiling a common neglected tropical disease: actinomycotic mycetoma. QJM 2023; 116:950-951. [PMID: 37354532 DOI: 10.1093/qjmed/hcad151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Indexed: 06/26/2023] Open
Affiliation(s)
- C G Danny
- Department of DVL, Sree Balaji Medical College and Hospital, 7, CLC Works Road, Chromepet, Chennai, Tamil Nadu, 600044, India
| | - K Manoharan
- Department of DVL, Sree Balaji Medical College and Hospital, 7, CLC Works Road, Chromepet, Chennai, Tamil Nadu, 600044, India
| | - N A Kumar
- Department of DVL, Sree Balaji Medical College and Hospital, 7, CLC Works Road, Chromepet, Chennai, Tamil Nadu, 600044, India
| | - P T Sowbaghya
- Department of DVL, Sree Balaji Medical College and Hospital, 7, CLC Works Road, Chromepet, Chennai, Tamil Nadu, 600044, India
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2
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Vikraman D, Satheesan R, Rajendran M, Kumar NA, Johnson JB, R SK, Mahendran KR. Selective Translocation of Cyclic Sugars through Dynamic Bacterial Transporter. ACS Sens 2022; 7:1766-1776. [PMID: 35671512 DOI: 10.1021/acssensors.2c00943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The selective translocation of molecules through membrane pores is an integral process in cells. We present a bacterial sugar transporter, CymA of unusual structural conformation due to a dynamic N terminus segment in the pore, reducing its diameter. We quantified the translocation kinetics of various cyclic sugars of different charge, size, and symmetry across native and truncated CymA devoid of the N terminus using single-channel recordings. The chemically divergent cyclic hexasaccharides bind to the native and truncated pore with high affinity and translocate effectively. Specifically, these sugars bind and translocate rapidly through truncated CymA compared to native CymA. In contrast, larger cyclic heptasaccharides and octasaccharides do not translocate but bind to native and truncated CymA with distinct binding kinetics highlighting the importance of molecular charge, size and symmetry in translocation consistent with liposome assays. Based on the sugar-binding kinetics, we suggest that the N terminus most likely resides inside the native CymA barrel, regulating the transport rate of cyclic sugars. Finally, we present native CymA as a large nanopore sensor for the simultaneous single-molecule detection of various sugars at high resolution, establishing its functional versatility. This natural pore is expected to have several applications in nanobiotechnology and will help further our understanding of the fundamental mechanism of molecular transport.
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Affiliation(s)
- Devika Vikraman
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.,Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Remya Satheesan
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.,Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Mangaiyarkarasi Rajendran
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Nisha Asok Kumar
- Manipal Academy of Higher Education, Manipal, Karnataka 576104, India.,Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala 695014, India
| | - John Bernet Johnson
- Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala 695014, India
| | - Smrithi Krishnan R
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.,Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Kozhinjampara R Mahendran
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
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3
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Mukesh RK, Kalam AA, Nag J, Jaikumar VS, Kunnakkadan U, Kumar NA, Suma SM, Rajavelu A, Johnson JB. Chandipura virus induces cell death in cancer cell lines of human origin and promotes tumor regression in vivo. Mol Ther Oncolytics 2021; 23:254-265. [PMID: 34761105 PMCID: PMC8554107 DOI: 10.1016/j.omto.2021.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 09/20/2021] [Accepted: 09/29/2021] [Indexed: 11/25/2022]
Abstract
Chandipura virus (CHPV) is an emerging human pathogen of great clinical significance. In this study, we have investigated the susceptibility pattern of both normal and cancer cell lines of human origin to wild-type (wt) CHPV in order to explore the possibility of developing CHPV as an oncolytic vector (OV). Marked cytopathic effect along with enhanced virus output was observed in cancer cell lines (HeLa, A549, U-138, PC-3, and HepG2) in comparison to normal human adult dermal fibroblast (HADF) cells. At an MOI of 0.1, cancer cell lines were differentially susceptible to CHPV, with cells like HeLa and U-138 having pronounced cell death, while the PC-3 were comparatively resistant. All cell lines used in the study except U-138 restricted CHPV infection to varying degrees with IFN-β pre-treatment and supplementation of interferon (IFN) could neither activate the IFN signaling pathway in U-138 cells. Finally, U-138 tumor xenografts established in non-obese diabetic severe combined immunodeficiency (NOD/SCID) mice showed significant delay in tumor growth in the CHPV-challenged animals. Thus, targeted cytopathic effect in cancer cells at a very low dose with restricted replication in normal cells offers a rationale to exploit CHPV as an oncolytic vector in the future.
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Affiliation(s)
- Reshma Koolaparambil Mukesh
- Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, Kerala, India.,Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Azeem Abdul Kalam
- Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, Kerala, India
| | - Joydeep Nag
- Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, Kerala, India.,Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Vishnu Sunil Jaikumar
- Animal Research Facility, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, Kerala, India
| | - Umerali Kunnakkadan
- Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, Kerala, India.,Department of Biotechnology, University of Kerala, Thiruvananthapuram 695581, Kerala, India
| | - Nisha Asok Kumar
- Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, Kerala, India.,Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | | | - Arumugam Rajavelu
- Pathogen Biology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, Kerala, India
| | - John Bernet Johnson
- Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, Kerala, India
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4
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Asok Kumar N, Muraleedharan Suma S, Kunnakkadan U, Nag J, Koolaparambil Mukesh R, Lyles DS, Johnson JB. Functional Dissection of the Dominant Role of CD55 in Protecting Vesicular Stomatitis Virus against Complement-Mediated Neutralization. Viruses 2021; 13:v13030373. [PMID: 33652918 PMCID: PMC7996768 DOI: 10.3390/v13030373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/05/2021] [Accepted: 02/19/2021] [Indexed: 11/16/2022] Open
Abstract
The human complement system is an important part of the innate immune system. Its effector pathways largely mediate virus neutralization. Vesicular stomatitis virus (VSV) activates the classical pathway of the complement, leading to virus neutralization by lysis. Two host-derived membrane-associated regulators of complement activation (RCA), CD55 and CD46, which are incorporated into the VSV envelope during egress, confer protection by delaying/resisting complement-mediated neutralization. We showed previously that CD55 is more effective than CD46 in the inhibition of neutralization. In this study, we identified that, at the protein level, VSV infection resulted in the down-regulation of CD46 but not CD55. The mRNA of both the RCAs was significantly down-regulated by VSV, but it was delayed in the case of CD55. The immunoblot analysis of the levels of RCAs in the progeny virion harvested at three specific time intervals, points to an equal ratio of its distribution relative to viral proteins. Besides reconfirming the dominant role of CD55 over CD46 in shielding VSV from complement, our results also highlight the importance of the subtle modulation in the expression pattern of RCAs in a system naturally expressing them.
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Affiliation(s)
- Nisha Asok Kumar
- Pathogen Biology, Virology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, Kerala 695014, India; (N.A.K.); (S.M.S.); (U.K.); (J.N.); (R.K.M.)
- Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Sreenath Muraleedharan Suma
- Pathogen Biology, Virology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, Kerala 695014, India; (N.A.K.); (S.M.S.); (U.K.); (J.N.); (R.K.M.)
| | - Umerali Kunnakkadan
- Pathogen Biology, Virology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, Kerala 695014, India; (N.A.K.); (S.M.S.); (U.K.); (J.N.); (R.K.M.)
- Department of Biotechnology, University of Kerala, Thiruvananthapuram, Kerala 695581, India
| | - Joydeep Nag
- Pathogen Biology, Virology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, Kerala 695014, India; (N.A.K.); (S.M.S.); (U.K.); (J.N.); (R.K.M.)
- Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Reshma Koolaparambil Mukesh
- Pathogen Biology, Virology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, Kerala 695014, India; (N.A.K.); (S.M.S.); (U.K.); (J.N.); (R.K.M.)
- Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Douglas S. Lyles
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA;
| | - John Bernet Johnson
- Pathogen Biology, Virology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, Kerala 695014, India; (N.A.K.); (S.M.S.); (U.K.); (J.N.); (R.K.M.)
- Correspondence:
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5
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Abstract
Complement, a part of the innate arm of the immune system, is integral to the frontline defense of the host against innumerable pathogens, which includes RNA viruses. Among the major groups of viruses, RNA viruses contribute significantly to the global mortality and morbidity index associated with viral infection. Despite multiple routes of entry adopted by these viruses, facing complement is inevitable. The initial interaction with complement and the nature of this interaction play an important role in determining host resistance versus susceptibility to the viral infection. Many RNA viruses are potent activators of complement, often resulting in virus neutralization. Yet, another facet of virus-induced activation is the exacerbation in pathogenesis contributing to the overall morbidity. The severity in disease and death associated with RNA virus infections shows a tip in the scale favoring viruses. Growing evidence suggest that like their DNA counterparts, RNA viruses have co-evolved to master ingenious strategies to remarkably restrict complement. Modulation of host genes involved in antiviral responses contributed prominently to the adoption of unique strategies to keep complement at bay, which included either down regulation of activation components (C3, C4) or up regulation of complement regulatory proteins. All this hints at a possible “hijacking” of the cross-talk mechanism of the host immune system. Enveloped RNA viruses have a selective advantage of not only modulating the host responses but also recruiting membrane-associated regulators of complement activation (RCAs). This review aims to highlight the significant progress in the understanding of RNA virus–complement interactions.
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Affiliation(s)
- Nisha Asok Kumar
- Viral Disease Biology, Department of Pathogen Biology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India.,Manipal Academy of Higher Education, Manipal, India
| | - Umerali Kunnakkadan
- Viral Disease Biology, Department of Pathogen Biology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India.,Department of Biotechnology, University of Kerala, Thiruvananthapuram, India
| | - Sabu Thomas
- Cholera and Biofilm Research Lab, Department of Pathogen Biology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
| | - John Bernet Johnson
- Viral Disease Biology, Department of Pathogen Biology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
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6
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Kumar NA, Johnson JB. Potential role of vesicular stomatitis virus signatures in complement activation and modulation. Mol Immunol 2018. [DOI: 10.1016/j.molimm.2018.06.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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7
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Ashwanikumar N, Kumar NA, Saneesh Babu PS, Sivakumar KC, Vadakkan MV, Nair P, Hema Saranya I, Asha Nair S, Vinod Kumar GS. Self-assembling peptide nanofibers containing phenylalanine for the controlled release of 5-fluorouracil. Int J Nanomedicine 2016; 11:5583-5594. [PMID: 27822037 PMCID: PMC5087806 DOI: 10.2147/ijn.s104707] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The study shows that RADA-F6 peptide with pH-responsive self-assembling nature can be effectively used as a drug delivery system for the sustained release of a potent anticancer drug 5-fluorouracil (5-FU) at basic pH. As 5-FU contains the aromatic pyrimidine ring, RADA-F6 system is suitable for entrapping an aromatic drug due to effective π-π stacking with phenylalanine and be able to show better controlled release behavior. The stability and controlled release nature of RADA-F6 in different conditions followed by 5-FU entrapment at in silico conditions was confirmed by molecular dynamics simulation taking RADA-16 as control. Cytotoxicity of the drug-loaded RADA-F6 was measured by MTT assay and cellular uptake by confocal microscopy. Physicochemical characterization and further Western blot analysis and flow cytometric studies confirm that RADA-F6 can be successfully used as an efficient vector for pH-sensitive, controlled 5-FU delivery system.
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Affiliation(s)
| | | | | | - Krishnankutty C Sivakumar
- Distributed Information Sub-Centre (Bioinformatics Centre), Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, India
| | | | - Parvathi Nair
- Chemical Biology, Nano Drug Delivery Systems, Bio-Innovation Center
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8
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Kumar NA, Lyles DS, Johnson JB. Recruitment of CD46 and CD55 by Vesicular Stomatitis Virus is a specific modulatory function adopted by the virus to evade complement mediated neutralization. Immunobiology 2016. [DOI: 10.1016/j.imbio.2016.06.203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Kuriakose MA, Ramdas K, Dey B, Iyer S, Rajan G, Elango KK, Suresh A, Ravindran D, Kumar RR, R P, Ramachandran S, Kumar NA, Thomas G, Somanathan T, Ravindran HK, Ranganathan K, Katakam SB, Parashuram S, Jayaprakash V, Pillai MR. A Randomized Double-Blind Placebo-Controlled Phase IIB Trial of Curcumin in Oral Leukoplakia. Cancer Prev Res (Phila) 2016; 9:683-91. [PMID: 27267893 DOI: 10.1158/1940-6207.capr-15-0390] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 04/15/2016] [Indexed: 11/16/2022]
Abstract
Oral leukoplakia is a potentially malignant lesion of the oral cavity, for which no effective treatment is available. We investigated the effectiveness of curcumin, a potent inhibitor of NF-κB/COX-2, molecules perturbed in oral carcinogenesis, to treat leukoplakia. Subjects with oral leukoplakia (n = 223) were randomized (1:1 ratio) to receive orally, either 3.6 g/day of curcumin (n = 111) or placebo (n = 112), for 6 months. The primary endpoint was clinical response obtained by bi-dimensional measurement of leukoplakia size at recruitment and 6 months. Histologic response, combined clinical and histologic response, durability and effect of long-term therapy for an additional six months in partial responders, safety and compliance were the secondary endpoints. Clinical response was observed in 75 (67.5%) subjects [95% confidence interval (CI), 58.4-75.6] in the curcumin and 62 (55.3%; 95% CI, 46.1-64.2) in placebo arm (P = 0.03). This response was durable, with 16 of the 18 (88.9%; 95% CI, 67.2-96.9) subjects with complete response in curcumin and 7 of 8 subjects (87.5%) in placebo arm, demonstrating no relapse after 6 months follow-up. Difference in histologic response between curcumin and placebo was not significant (HR, 0.88, 95% CI, 0.45-1.71; P = 0.71). Combined clinical and histologic response assessment indicated a significantly better response with curcumin (HR, 0.50; 95% CI, 0.27-0.92; P = 0.02). Continued therapy, in subjects with partial response at 6 months, did not yield additional benefit. The treatment did not raise any safety concerns. Treatment of oral leukoplakia with curcumin (3.6 g for six months), thus was well tolerated and demonstrated significant and durable clinical response for 6 months. Cancer Prev Res; 9(8); 683-91. ©2016 AACR.
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Affiliation(s)
- Moni Abraham Kuriakose
- Amrita Institute of Medical Sciences, Kochi, India. Mazumdar Shaw Cancer Center, Bengaluru, India. Roswell Park Cancer Institute, Buffalo, New York.
| | | | - Bindu Dey
- Department of Biotechnology, Ministry of Science and Technology, New Delhi, India
| | | | | | | | - Amritha Suresh
- Amrita Institute of Medical Sciences, Kochi, India. Mazumdar Shaw Cancer Center, Bengaluru, India. Roswell Park Cancer Institute, Buffalo, New York
| | | | | | - Prathiba R
- Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
| | | | - Nisha Asok Kumar
- Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
| | - Gigi Thomas
- Regional Cancer Center, Thiruvananthapuram, India
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10
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Ashwanikumar N, Kumar NA, Asha Nair S, Vinod Kumar GS. 5-Fluorouracil-lipid conjugate: potential candidate for drug delivery through encapsulation in hydrophobic polyester-based nanoparticles. Acta Biomater 2014; 10:4685-4694. [PMID: 25110286 DOI: 10.1016/j.actbio.2014.07.032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 07/23/2014] [Accepted: 07/30/2014] [Indexed: 12/20/2022]
Abstract
The encapsulation of 5-fluorouracil (5-FU) in hydrophobic polymeric materials is made feasible by a lipid-based prodrug approach. A lipid-5-FU conjugate of 5-FU with palmitic acid was synthesized in two-step process. A synthesized dipalmitoyl derivative (5-FUDIPAL) was characterized using Fourier transform infrared spectroscopy and (1)H-nuclear magnetic resonance. The 5-FUDIPAL was encapsulated in polyester-based polymers by the double emulsion-solvent evaporation method. The nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy and dynamic light scattering. The thermal stability was assessed by differential scanning calorimetry data. In vitro release kinetics measurements of the drug from nanoparticles showed the controlled release pattern over a period of time. Cytotoxicity measurements by MTT assay confirmed that dipalmitoyl derivative in nano formulation successfully inhibited the cell growth. Thus the combined physical and biological evaluation of the different polyester-based nanoparticle containing the modified drug showed a facile approach to delivering 5-FU to the tumour site with enhanced efficacy.
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Affiliation(s)
- N Ashwanikumar
- Chemical Biology, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - Nisha Asok Kumar
- Cancer Research Programme, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - S Asha Nair
- Cancer Research Programme, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - G S Vinod Kumar
- Chemical Biology, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram 695 014, Kerala, India.
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Ashwanikumar N, Kumar NA, Nair SA, Kumar GSV. Dual drug delivery of 5-fluorouracil (5-FU) and methotrexate (MTX) through random copolymeric nanomicelles of PLGA and polyethylenimine demonstrating enhanced cell uptake and cytotoxicity. Colloids Surf B Biointerfaces 2014; 122:520-528. [PMID: 25108479 DOI: 10.1016/j.colsurfb.2014.07.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 12/21/2022]
Abstract
We now report the synthesis of a random copolymer of poly-lactic-co-glycolic acid (PLGA) grafted branched polyethylenimine (BPEI) and the use of it as a multi drug delivery system (DDS). The methotrexate (MTX) was conjugated to BPEI through DCC/NHS chemistry. The copolymer-drug conjugate (PBP-MTX) was characterised by FT-IR and (1)H NMR spectroscopy. The PBP-MTX was converted into nanomicelles with entrapped 5-fluorouracil (5-FU) through nanoprecipitation technique. The size, shape, morphology and surface charge of the nanomicelles were confirmed using different techniques. The thermal behaviour and distribution of both conjugated and entrapped drug through the polymeric matrix were assessed by differential scanning calorimetry (DSC) and powder X-ray diffraction analysis (PXRD). In vitro drug release pattern of the nanomicelles was examined to ascertain the release pattern of two drugs namely 5-FU and MTX. The cellular uptake studies demonstrated higher uptake of the nanomicelles in colon cancer cell line HCT 116. Further the cytotoxicity evaluation of nanomicelles illustrated promising action which confirms the use of the system as a potential DDS to colon cancer.
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Affiliation(s)
- N Ashwanikumar
- Chemical Biology, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - Nisha Asok Kumar
- Cancer Research Programme, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - S Asha Nair
- Cancer Research Programme, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram 695 014, Kerala, India
| | - G S Vinod Kumar
- Chemical Biology, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram 695 014, Kerala, India.
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12
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Ashwanikumar N, Kumar NA, Nair SA, Kumar GSV. Phenylalanine-containing self-assembling peptide nanofibrous hydrogel for the controlled release of 5-fluorouracil and leucovorin. RSC Adv 2014. [DOI: 10.1039/c4ra04393f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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13
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Simon AM, Jagadeeshan S, Abraham E, Akhilandeshwaran A, Pillai JJ, Kumar NA, Sivakumari AN, Kumar GSV. Poly (D,L-lactic-co-glycolide) nanoparticles for the improved therapeutic efficacy of all-trans-retinoic acid: a study of acute myeloid leukemia (AML) cell differentiation in vitro. Med Chem 2012; 8:805-10. [PMID: 22741806 DOI: 10.2174/157340612802084333] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 03/07/2012] [Accepted: 03/20/2012] [Indexed: 11/22/2022]
Abstract
All-trans-retinoic acid reverses malignant cell growth and induces cell differentiation and apoptosis. Poor aqueous solubility and uncertain bioavailability are the limiting factors for using all-trans-retinoic acid for tumor therapy. The objective of present study was to encapsulate the hydrophobic drug all-trans-retinoic acid in the polymer poly (lactide-coglycolide). The encapsulation was expected to improve the bioavailability and solubility of the drug. Oil in water single emulsion solvent evaporation technique used for the preparation efficiently encapsulated about 60% of the drug. The drug release profile showed a biphasic pattern with 70% of the drug being released in first 48 hrs and the residual drug showing a slow controlled release reaching up to 8 days. The particle size of 150-200 nm as determined with TEM was ideal for tumor targeting. All-trans-retinoic acid loaded nanoparticles were efficient to induce differentiation and blocked the proliferation of HL-60 cells invitro. These studies also revealed that the dosage of drug required for the therapeutic effects have been reduced efficiently. Our studies thereby demonstrate that Poly (lactide-co-glycolide) based nanoparticles may be efficient for parenteral administration of the drug.
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Affiliation(s)
- Aswathy Mary Simon
- Chemical Biology, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram-695 014, Kerala, India
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14
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Abstract
Methacrylic-based copolymers in drug-delivery systems demonstrate a pH-sensitive drug-releasing behavior in the colon. In this study, copolymers of methacrylic acid and 2-ethyl hexyl acrylate were prepared using a microemulsion polymerization technique. The purified copolymer was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. 5-Fluorouracil (5-FU) was entrapped within methacrylic-based copolymers by a solvent evaporation method. The size of the nanogels formed was characterized by transmission electron microscopy and atomic force microscopy. In vitro drug-release studies using phosphate-buffered saline at different pH levels demonstrated the sustained release of 5-FU and its pH dependence. Cell proliferation assay of a human colon tumor colon cancer cell line (HCT-116) was performed and showed that the nanogels containing 5-FU exhibited considerable cytotoxicity in comparison with free 5-FU. Cell uptake of the nanogels was also monitored using confocal microscopy. Western blot analysis and flow cytometry studies confirmed that the nanogels could be successfully used as an efficient vector for pH-sensitive and controlled delivery of drugs specifically targeted to the colon.
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Affiliation(s)
- N Ashwanikumar
- Chemical Biology, Rajiv Gandhi Center for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, India
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Menon B, Kumar NA, Sudhakaran PR. Modulation of alpha1beta1 integrin mediated adhesion of hepatocytes to collagen IV and laminin by divalent cations. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 2001; 38:159-65. [PMID: 11693378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Cell matrix interactions play a critical role in hepatic development and regeneration after acute injury. These interactions are mediated by transmembrane receptors belonging mainly to the integrin family. We have tried to assess the role of divalent cations in mediating attachment of hepatocytes to matrix proteins like collagen IV (Col IV) and laminin (Ln). The three cations examined viz. Ca2+, Mg2+ and Mn2+ showed attachment promoting activity. Since alpha1beta1 integrin is a common receptor for col IV and LN in liver, the effect of cations in its binding to these matrix proteins was studied. Although cations in general enhanced the binding, different cations exhibited differential effect in promoting the binding for different ligands. Mg2+ ions were more effective in promoting the binding of alpha1beta1 integrin to col IV but Ca2+ proved to be more effective one for Ln. Kinetic analysis of binding in dot blot assays using different concentrations of cations showed that while Mg2+ was active at low concentrations Ca2+ and Mn2+ promoted the binding more at higher concentrations. Absence of competitive effect in binding studies showed that they bind at different sites on the receptor. Differential effects of cations in promoting the binding of alpha1beta1 integrin to Col IV and Ln suggest that changes in level of diffusible cations can modulate affinity of the common receptor alpha1beta1 integrin to its ligands and can influence adhesion of hepatic cells to different matrix proteins during hepatic development and regeneration.
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Affiliation(s)
- B Menon
- Department of Biochemistry, University of Kerala, Kariavattom, Trivandrum, India
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Salahudeen MM, Inbasekaran V, Kumar NA, Rajan DK, Sivakozhundu MK. Otogenic intracranical suppuration at a rare site - letter to editor. Neurol India 2001; 49:101. [PMID: 11303257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Affiliation(s)
- N A Kumar
- Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104, USA
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Kumar NA, Schnall MD. MR imaging: its current and potential utility in the diagnosis and management of breast cancer. Magn Reson Imaging Clin N Am 2000; 8:715-28. [PMID: 11149675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The rapid evolution of the treatment of breast cancer has been paralleled by a similar rapid improvement in the imaging of breast cancer. High-resolution contrast-enhanced MR imaging of the breast has recently emerged as a sensitive instrument for the detection of breast cancer. The sensitivity of MR imaging makes it an excellent tool in specific clinical situations, such as the detection of local recurrence in patients who have received breast-conservation therapy. Furthermore, MR imaging of the breast has the potential to be a powerful aid in presurgical planning and to be a useful adjunct to mammography in selected patients. MR imaging, however, has a significant false-positive rate, is not readily available in all areas, and is more expensive than mammography and sonography. It also remains unclear if alterations of management plans based on MR imaging findings actually benefit affected patients. Therefore rigorous clinical trials are needed to define precisely the exact role that MR imaging should play in the diagnosis and management of breast cancer patients.
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Affiliation(s)
- N A Kumar
- Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104, USA
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Abstract
We measured the intracellular levels of free cytoplasmic calcium in different phases of the cell cycle in viable rat fibroblasts, using two parameter flow cytometric analysis with Hoechst 33342 as the DNA specific dye and Fluo-3 as the calcium sensitive dye. We studied changes in calcium levels during the G1 phase of cell cycle by arresting cells with chemical agents such as staurosporine and hydroxyurea or by density dependent arrest of cell growth. We show that levels of calcium are lowest at the beginning of G1 phase but rise steadily with its progression and culminate at the G1/S border. Our results suggest that complex changes occur in calcium levels during the process of mitotic division. During progression of S and G2 phases, calcium levels decline and increase respectively. Our results offer a new methodology to estimate intracellular calcium levels in specific phases of the cell cycle. Based upon these results we propose a general scheme representing the changes in the intracellular calcium concentration during the progression of the cell cycle.
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Affiliation(s)
- G Pande
- Centre for Cellular and Molecular Biology, Hyderabad, India.
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Kumar NA, Ranganadham P, Bhaskar G, Chowdhury AR. Multiple calvarial cavernous haemangiomas: case report and review of the literature. Neuroradiology 1996; 38 Suppl 1:S83-5. [PMID: 8811689 DOI: 10.1007/bf02278128] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Multiple cavernous haemangiomas of the skull with erosion of the inner table and symptomatic intracranial extension were observed in a middle-aged woman. Plain radiographic and CT features are described. The literature relevant to these unusual features is briefly discussed.
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Affiliation(s)
- N A Kumar
- Department of Radiology and Imaging, Nizam's Institute of Medical Sciences, Panjagutta, Hyderabad, India
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Gajendran R, Muthukumar N, Pushparaj K, Kumar NA, Gurunathan J. Pituitary astrocytoma (pituicytoma). J Indian Med Assoc 1994; 92:201. [PMID: 7930661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- R Gajendran
- Department of Neurosurgery, Madurai Medical College and Government Rajaji Hospital
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Meythaler JM, Korkor AB, Nanda T, Kumar NA, Fallon M. Immobilization hypercalcemia associated with Landry-Guillain-Barré syndrome. Successful therapy with combined calcitonin and etidronate. Arch Intern Med 1986; 146:1567-71. [PMID: 3089187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Two patients with immobilization hypercalcemia associated with Landry-Guillain-Barré syndrome had marked hypercalciuria (890 and 1136 mg/d [22.2 and 28.3 mmol/d]) and radiologic evidence of generalized osteopenia. Parathyroid hormone levels were either low or normal by C-terminal radioimmunoassay. Subtotal parathyroidectomy was performed in the one patient, with no improvement in serum or urinary calcium levels. A bone biopsy specimen revealed decreased cellular activity in the first patient and increased bone resorption in the second patient. Treatment with intravenous saline, furosemide, oral phosphate supplementation, mithramycin, and calcitonin alone was ineffective in lowering serum or urinary calcium levels. However, when subcutaneous calcitonin combined with oral etidronate disodium was used, a reduction in the serum calcium level was observed within two days of therapy. Within one week of the start of this combined therapy, the calcium level returned to normal and urinary calcium excretion was substantially reduced.
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Kumar NA, Rao MN. Quantitative correlation between molar refractivity and the inhibition of dihydrofolate reductase by 2,4-diamino-5-benzylpyrimidines. Indian J Biochem Biophys 1986; 23:58-60. [PMID: 3525396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Inpasekaran V, Kumar NA, Natarajan M. Intrafourth ventricular cysticercosis. J Indian Med Assoc 1985; 83:356-7. [PMID: 3833978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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