Publications by authors named "Ramkrishna Sen"

64 Publications

Microsphere embedded hydrogel construct - binary delivery of alendronate and BMP-2 for superior bone regeneration.

J Mater Chem B 2021 Sep 16;9(34):6856-6869. Epub 2021 Aug 16.

Biomaterials and Tissue Engineering Laboratory, School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur - 721302, India.

Biomimetic delivery of osteoinductive growth factors via an osteoconductive matrix is an interesting approach for stimulating bone regeneration. In this context, the bone extracellular matrix (ECM) has been explored as an optimal delivery system, since it releases growth factors in a spatiotemporal manner from the matrix. However, a bone ECM hydrogel alone is weak, unstable, and prone to microbial contamination and also has been reported to have significantly reduced bone morphogenic protein-2 (BMP-2) post decellularization. In the present work, a microsphere embedded osteoinductive decellularized bone ECM/oleoyl chitosan based hydrogel construct (BOC) was developed as a matrix allowing dual delivery of an anti-resorptive drug (alendronate, ALN, via the microspheres) and BMP-2 (via the hydrogel) for a focal tibial defect in a rabbit model. The synthesized gelatin microspheres (GMs) were spherical in shape with diameter ∼32 μm as assessed by SEM analysis. The BOC construct showed sustained release of ALN and BMP-2 under the studied conditions. Interestingly, amniotic membrane-derived stem cells (HAMSCs) cultivated on the hydrogel construct demonstrated excellent biocompatibility, cell viability, and active proliferation potential. Additionally, cell differentiation on the constructs showed an elevated expression of osteogenic genes in an RT-PCR study along with enhanced mineralized matrix deposition as demonstrated by alkaline phosphatase (ALP) assay and alizarin red assay. The hydrogel construct was witnessed to have improved neo-vascularization potential in a chick chorioalantoic membrane (CAM) assay. Also, histological and computed tomographic findings evidenced enhanced bone regeneration in the group treated with the BOC/ALN/BMP hydrogel construct in a rabbit tibial defect model. To conclude, the developed multifunctional hydrogel construct acts as an osteoinductive and osteoconductive platform facilitating controlled delivery of ALN and BMP-2, essential for stimulating bone tissue regeneration.
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http://dx.doi.org/10.1039/d1tb00255dDOI Listing
September 2021

Enhanced biodegradation of total petroleum hydrocarbons by implementing a novel two-step bioaugmentation strategy using indigenous bacterial consortium.

J Environ Manage 2021 Aug 19;292:112746. Epub 2021 May 19.

School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, West Bengal, 721302, India; Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal, 721302, India. Electronic address:

In the present study, a two-step bioaugmentation strategy (TSBS) was implemented by using indigenous bacterial consortium to enhance the degradation of total petroleum hydrocarbons (TPH) from petroleum refinery sludge (PRS). A bacterial consortium was developed using four indigenous isolated strains, Dietzia sp. IRB191, Dietzia sp. IRB192, Staphylococcus sp. BSM19 and Stenotrophomonas sp. IRB19 from PRS. The optimum conditions of pH, temperature, and sludge concentration were 7, 34 °C, and 2% (w/v), respectively, for maximum TPH degradation, obtained using one variable at a time approach. Under the optimal culture conditions, the developed consortium was inoculated twice to the culturing medium, at the beginning (0 day) and again on the 10th day for implementing a novel TSBS. The maximum TPH degradation of 91.5 ± 2.28% was found with TSBS, which was 1.18 times higher than that of SSBS (77.3 ± 2.6%) in 15 days of incubation. GC-FID study also confirmed that the TPH present in the PRS was effectively degraded by the bacterial consortium with TSBS. The TPH degradation by using TSBS proceeded according to the first-order kinetics with a rate constant of 0.155 d. Hence, biodegradation using a TSBS can be considered an effective and eco-friendly process for safe disposal of petroleum refinery sludge.
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http://dx.doi.org/10.1016/j.jenvman.2021.112746DOI Listing
August 2021

Apigenin-loaded galactose tailored PLGA nanoparticles: A possible strategy for liver targeting to treat hepatocellular carcinoma.

Colloids Surf B Biointerfaces 2021 Aug 20;204:111778. Epub 2021 Apr 20.

Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India. Electronic address:

Hepatocellular carcinoma (HCC) is the most common hepatic malignancy worldwide. Recent reports focusing on the efficacy of apigenin-loaded nanoparticles (NPs) in combating the progress of HCC encouraged us to develop galactose-tailored PLGA NPs loaded with apigenin (API-GAL-NPs) for active liver targeting to treat HCC. Two kinds of apigenin NPs, such as apigenin-PLGA NPs (API-NPs) and API-GAL-NPs were fabricated and characterized by size, surface morphology, encapsulation efficacy, and in vitro drug release kinetics. In vitro assays were performed on HepG2 cells to check the cellular internalization, cytotoxic potential, and apoptotic potential of free apigenin (API), API-NPs, and API-GAL-NPs. In this stdy, API-GAL-NPs exhibited improved cellular internalization of API resulting in significantly high cytotoxic and apoptotic potentials to HepG2 cells over API and API-NPs. In in vivo studies, API-GAL-NPs exhibited a better protective effect against DEN-induced HCC in rats evidenced by the significant reduction of nodule formation, downregulation of matrix metalloproteinases (MMP-2 and MMP-9), and induction of apoptosis in the liver than API and API-NPs. Histopathological studies and scintigraphic imaging also confirmed that API-GAL-NPs treatment achieved better therapeutic efficacy against DEN-induced HCC in rats over API-NPs. In conclusion, API-GAL-NPs may serve as a potential therapeutic agent against HCC in the future by achieving improved liver targeting.
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http://dx.doi.org/10.1016/j.colsurfb.2021.111778DOI Listing
August 2021

Apigenin-Loaded PLGA-DMSA Nanoparticles: A Novel Strategy to Treat Melanoma Lung Metastasis.

Mol Pharm 2021 05 29;18(5):1920-1938. Epub 2021 Mar 29.

Department of Polymer Science and Technology, University College of Science and Technology, University of Calcutta, Kolkata 700009, India.

The flavone apigenin (APG), alone as well as in combination with other chemotherapeutic agents, is known to exhibit potential anticancer effects in various tumors and inhibit growth and metastasis of melanoma. However, the potential of apigenin nanoparticles (APG-NPs) to prevent lung colonization of malignant melanoma has not been well investigated. APG-loaded PLGA-NPs were surface-functionalized with -2,3-dimercaptosuccinic acid (DMSA) for the treatment of melanoma lung metastasis. DMSA-conjugated APG-loaded NPs (DMSA-APG-NPs) administered by an oral route exhibited sustained APG release and showed considerable enhancement of plasma half-life, value, and bioavailability compared to APG-NPs both in plasma and the lungs. DMSA-conjugated APG-NPs showed comparably higher cellular internalization in B16F10 and A549 cell lines compared to that of plain NPs. Increased cytotoxicity was observed for DMSA-APG-NPs compared to APG-NPs in A549 cells. This difference between the two formulations was lower in B16F10 cells. Significant depolarization of mitochondrial transmembrane potential and an enhanced level of caspase activity were observed in B16F10 cells treated with DMSA-APG-NPs compared to APG-NPs as well. Western blot analysis of various proteins was performed to understand the mechanism of apoptosis as well as prevention of melanoma cell migration and invasion. DMSA conjugation substantially increased accumulation of DMSA-APG-NPs given by an intravenous route in the lungs compared to APG-NPs at 6 and 8 h. This was also corroborated by scintigraphic imaging studies with radiolabeled formulations administered by an intravenous route. Conjugation also allowed comparatively higher penetration as evident from an three-dimensional tumor spheroid model study. Finally, the potential therapeutic efficacy of the formulation was established in experimental B16F10 lung metastases, which suggested an improved bioavailability with enhanced antitumor and antimetastasis efficacy of DMSA-conjugated APG-NPs following oral administration.
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http://dx.doi.org/10.1021/acs.molpharmaceut.0c00977DOI Listing
May 2021

Treatment of petroleum refinery sludge by petroleum degrading bacterium IRB19 as an efficient novel technology.

J Environ Sci Health A Tox Hazard Subst Environ Eng 2021 30;56(2):226-239. Epub 2020 Dec 30.

Department of Chemical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India.

Petroleum hydrocarbons (PHCs) in petroleum refinery sludge (PRS) are the most adverse components because of their toxic nature, which are harmful to human health and the aquatic ecosystem. This study aimed to identify and characterize an indigenous bacterium isolated from PRS of Indian oil corporation ltd. (IOCL), Haldia, India, and evaluate its performance for biodegradation of total petroleum hydrocarbon (TPH) of PRS. The bacterium molecularly characterized as sp. IRB19 by 16S rRNA sequencing and phylogenetic analysis. The strain IRB19 showed a significant ability to utilize four different oils (kerosene, diesel, petrol and hexadecane) . IRB19 could able to degrade up to 65 ± 2.4% of TPH in 28 d of incubation. Solvent extraction study showed that PRS contain 180.57 ± 3.44 g kg of TPH and maltene fraction composed of aliphatic, aromatics and polar components of 52 ± 4, 39 ± 2 and 9 ± 1%, respectively. The TPH degradation best fitted for the Gompertz model and followed the first-order kinetics having the rate constant () and half-life period ( ) of 0.036 d and 19 d, respectively. Results of this study verified the suitability of the novel strain IRB19 for the biodegradation of PHCs.
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http://dx.doi.org/10.1080/10934529.2020.1866924DOI Listing
February 2021

Decellularized bone matrix/oleoyl chitosan derived supramolecular injectable hydrogel promotes efficient bone integration.

Mater Sci Eng C Mater Biol Appl 2021 Feb 9;119:111604. Epub 2020 Oct 9.

Biomaterials and Tissue Engineering Laboratory, School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India. Electronic address:

Hydrogels derived from decellularized extracellular matrix (ECM) have been widely used as a bioactive matrix for facilitating functional bone tissue regeneration. However, its poor mechanical strength and fast degradation restricts the extensive use for clinical application. Herein, we present a crosslinked decellularized bone ECM (DBM) and fatty acid modified chitosan (oleoyl chitosan, OC) based biohybrid hydrogel (DBM/OC) for delivering human amnion-derived stem cells (HAMSCs) for bone regeneration. DBM/OC hydrogel were benchmarked against collagen-I/OC (Col-I/OC) based hydrogel in terms of their morphological characteristics, rheological analysis, and biological performances. DBM/OC hydrogel with its endogenous growth factors recapitulates the nanofibrillar 3D tissue microenvironment with improved mechanical strength and also exhibited antimicrobial potential along with superior proliferation/differentiation ability. HAMSCs encapsulation potential of DBM/OC hydrogel was established by well spread cytoskeleton morphology post 14 days of cultivation. Further, ex-vivo chick chorioallantoic membrane (CAM) assay revealed excellent neovascularization potential of DBM/OC hydrogel. Subcutaneously implanted DBM/OC hydrogel did not trigger any severe immune response or infection in the host after 21 days. Also, DBM/OC hydrogels and HAMSCs encapsulated DBM/OC hydrogels were implanted at the tibial defect in a rabbit model to assess the bone regeneration ability. Quantitative micro-CT and histomorphological analysis demonstrated that HAMSCs encapsulated DBM/OC hydrogel can support more mature mineralized bone formation at the defect area compared to DBM/OC hydrogel or SHAM. These findings manifested the efficacy of DBM/OC hydrogel as a functional cell-delivery vehicle and osteoinductive template to accelerate bone regeneration.
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http://dx.doi.org/10.1016/j.msec.2020.111604DOI Listing
February 2021

Anticancer potential of docetaxel-loaded cobalt ferrite nanocarrier: an in vitro study on MCF-7 and MDA-MB-231 cell lines.

J Microencapsul 2021 Jan 30;38(1):36-46. Epub 2020 Nov 30.

Department of Physics, Jadavpur University, Kolkata, India.

Aim: To develop a biocompatible cobalt ferrite (CF-NP) nanodrug formulation using oleic acid and poly (d,l-lactide--glycolic) acid (PLGA) for the delivery of docetaxel (DTX) specifically to breast cancer cells.

Methods: The CF-NP were synthesised by hydrothermal method and conjugated with DTX in a PLGA matrix and were systematically characterised using XRD, FE-SEM, TEM, DLS, FTIR, TGA, SQUID etc. The drug loading, in vitro drug release, cellular uptake, cytotoxicity were evaluated and haemolytic effect was studied.

Results: The CF-NP showed good crystallinity with an average particle size of 21 nm and ferromagnetic nature. The DTX-loaded CF-NP (DCF-NP) showed 8.4% (w/w) drug loading with 81.8% loading efficiency with a sustained DTX release over time. An effective internalisation and anti-proliferative efficiency was observed in MCF-7 and MDA-MB-231 breast cancer cells and negligible haemolytic effect.

Conclusion: The DCF-NP can have the potential for the effective delivery of DTX for breast cancer treatment.
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http://dx.doi.org/10.1080/02652048.2020.1842529DOI Listing
January 2021

Folate decorated epigallocatechin-3-gallate (EGCG) loaded PLGA nanoparticles; in-vitro and in-vivo targeting efficacy against MDA-MB-231 tumor xenograft.

Int J Pharm 2020 Jul 25;585:119449. Epub 2020 May 25.

Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India. Electronic address:

Epigallocatechin-3-gallate (EGCG), a major polyphenolic constituent of green tea exhibits significant anti-cancer potential over a wide range of cancer cells. We have developed folate peptide decorated PLGA-NPs loaded with EGCG (FP-EGCG-NPs) to bind folate receptor (FR) specific breast cancer cell lines and evaluated their efficacy in pre-clinical studies. EGCG loaded PLGA nanoparticles (EGCG-NPs) were characterised for size, surface morphology, surface charge, encapsulation efficacy and in-vitro drug release kinetics. Cellular uptake and in-vitro cytotoxicities of free drug, folate peptide conjugated and unconjugated EGCG-NPs were investigated against FR positive MDA-MB-231 and MCF-7 cells. The conjugated nanoparticles exhibited promising cytotoxic potentials as well as significantly high cellular internalisation in MDA-MB-231 cells as compared to unconjugated one. It also ensured longer half life, higher plasma concentration, favourably high apoptotic potential and significantly high mitochondrial depolarization effect as compared to free EGCG. The loaded nanoparticles were radiolabeled with technetium-99m and their tumor selectivity in MDA-MB-231 tumor bearing nude mice was investigated by scintigraphic imaging study. Finally in-vivo therapeutic efficacy studies in tumor bearing nude mice were also done to evaluate the efficacy of the formulation for cancer treatment.
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http://dx.doi.org/10.1016/j.ijpharm.2020.119449DOI Listing
July 2020

Production, partial purification and characterization of a proteoglycan bioemulsifier from an oleaginous yeast.

Bioprocess Biosyst Eng 2020 Oct 14;43(10):1747-1759. Epub 2020 May 14.

Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal, Kharagpur, 721302, India.

In this study, Meyerozyma caribbica, an indigenously isolated oleaginous yeast, produced in media containing glucose a bioemulsifier that was partially characterized as a proteoglycan based on preliminary analysis. Optimization of carbon:nitrogen (C:N) ratio revealed 30:1 as the suitable ratio for enhanced production. Apart from higher emulsification activity (E: 70-80%), this molecule showed strong emulsion stability over a wide range of pH (2.0-9.0), salinity (0.05%-10%, w/v) and temperature (- 80 °C to + 50 °C). The current study emphasizes on the determination of critical media parameters for improved and stable bioemulsifier production coupled with partial characterization and identification of the molecule. Thus, a proteoglycan-based bioemulsifier with such a stable emulsifying property can serve as a versatile and potential component in food, cosmetics and pharmaceutical formulations.
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http://dx.doi.org/10.1007/s00449-020-02361-1DOI Listing
October 2020

Aptamer-Functionalized Drug Nanocarrier Improves Hepatocellular Carcinoma toward Normal by Targeting Neoplastic Hepatocytes.

Mol Ther Nucleic Acids 2020 Jun 5;20:34-49. Epub 2020 Feb 5.

Pharmaceutics Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Kolkata, India; Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India.

Site-specific delivery of chemotherapeutics specifically to neoplastic hepatocytes without affecting normal hepatocytes should be a focus for potential therapeutic management of hepatocellular carcinoma (HCC). The aptamer TLS 9a with phosphorothioate backbone modifications (L5) has not been explored so far for preferential delivery of therapeutics in neoplastic hepatocytes to induce apoptosis. Thus, the objective of the present investigation was to compare the therapeutic potential of L5-functionalized drug nanocarrier (PTX-NPL5) with those of the other experimental drug nanocarriers functionalized by previously reported HCC cell-targeting aptamers and non-aptamer ligands, such as galactosamine and apotransferrin. A myriad of well-defined investigations such as cell cycle analysis, TUNEL (terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick end labeling) assay, and studies related to apoptosis, histopathology, and immunoblotting substantiated that PTX-NPL5 had the highest potency among the different ligand-attached experimental formulations in inducing selective apoptosis in neoplastic hepatocytes via a mitochondrial-dependent apoptotic pathway. PTX-NPL5 did not produce any notable toxic effects in healthy hepatocytes, thus unveiling a new and a safer option in targeted therapy for HCC. Molecular modeling study identified two cell-surface biomarker proteins (tumor-associated glycoprotein 72 [TAG-72] and heat shock protein 70 [HSP70]) responsible for ligand-receptor interaction of L5 and preferential internalization of PTX-NPL5 via clathrin-mediated endocytosis in neoplastic hepatocytes. The potential of PTX-NPL5 has provided enough impetus for its rapid translation from the pre-clinical to clinical domain to establish itself as a targeted therapeutic to significantly prolong survival in HCC.
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http://dx.doi.org/10.1016/j.omtn.2020.01.034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7063179PMC
June 2020

Gemcitabine Co-Encapsulated with Curcumin in Folate Decorated PLGA Nanoparticles; a Novel Approach to Treat Breast Adenocarcinoma.

Pharm Res 2020 Feb 18;37(3):56. Epub 2020 Feb 18.

Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata, 700032, India.

Purpose: Curcumin (CUR), an antioxidant with p-glycoprotein inhibiting activity may be encapsulated with gemcitabine (GEM) as nanosuspension to enhance its anticancer potentiality synergistically.

Methods: Folate conjugated single (CUR/GEM) and dual (CUR + GEM) drug-loaded nanoformulations were prepared and evaluated for P-glycoprotein-1 (pgy-1) gene resistance, followed by in vitro cellular uptake and cytotoxicity assay in cells. The in vivo biodistribution and scintigraphic imaging was done after radiolabeling the nanoparticles with Technetium (99Tc). The tumor inhibition study was conducted in nude mice bearing MDA-MB-231 xenografts.

Results: The folate conjugated dual drug formulations (FCGNPs) gave better results in suppressing the pgy-1 gene and also showed higher cellular uptake, cytotoxicity, apoptosis, and cell cycle arrest. The radiolabeled nanoformulations were highly stable and FCGNPs showed higher accumulation in the MDA-MB-231 tumor region than folate unconjugated dual drug NPs (CGNPs) as evidenced by scintigraphic imaging and biodistribution studies. The in vivo therapeutic efficacy of FCGNPs was higher compared to unconjugated and respective single-drug formulations.

Conclusion: Two drugs in one platform lower breast adenocarcinoma by lowering drug resistance and improving cytotoxic effects.
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http://dx.doi.org/10.1007/s11095-020-2758-5DOI Listing
February 2020

A Comparative Investigation of the Ability of Various Aptamer-Functionalized Drug Nanocarriers to Induce Selective Apoptosis in Neoplastic Hepatocytes: In Vitro and In Vivo Outcome.

AAPS PharmSciTech 2020 Feb 5;21(3):89. Epub 2020 Feb 5.

Pharmaceutics Research Laboratory, Department of Pharmaceutical Technology, Jadavpur University, 188, Raja, S.C. Mullick Road, Kolkata, West Bengal, 700032, India.

Aptamers offer a significant promise to target various cancers including hepatocellular carcinoma (HCC), for their high affinity and ability to reach the target site(s), non-immunogenicity, and low cost. The targeting ability to neoplastic hepatocytes by the aptamer, TLS 9a with phosphorothioate backbone modification (designated as L5), has not been explored yet. Hence, we investigated the comparative potential of L5 with some other previously reported liver cancer cell-specific aptamers, conjugated on the surface of drug-nanocarriers. Various in vitro studies such as cytotoxicity, in vitro cellular uptake, cell cycle analysis, and investigations related to apoptosis were performed. In vivo studies carried out here include macroscopic and microscopic hepatic alterations in chemically induced hepatocarcinogenesis in rats, upon experimental treatments. The outcome of the investigations revealed that L5-functionalized drug-nanocarrier (PTX-NPL5) had the highest apoptotic potential compared with the other aptamer-conjugated experimental formulations. Further, its maximum internalization by neoplastic hepatocytes and minimum internalization by normal hepatocytes indicate that it had the potential to preferentially target the neoplastic hepatocytes. Data of in vivo studies revealed that PTX-NPL5 reduced tumor incidences and tumor progress. Superior potency of PTX-NPL5 may be due to the maximum affinity of L5 towards neoplastic hepatocytes resulting in maximum permeation of drug-nanocarrier in them. An effective site-specific targeting of neoplastic hepatocytes can be achieved by L5 for preferential delivery of therapeutics. Further, investigations are needed to identify the target protein(s) on neoplastic hepatocytes responsible for ligand-receptor interaction of L5.
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http://dx.doi.org/10.1208/s12249-020-1629-zDOI Listing
February 2020

Biofunctionalized nanomaterials for in situ clean-up of hydrocarbon contamination: A quantum jump in global bioremediation research.

J Environ Manage 2020 Feb 10;256:109913. Epub 2019 Dec 10.

Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal, 721302, India. Electronic address:

Interfacing organic or inorganic nanoparticles with biological entities or molecules or systems with the aim of developing functionalized nano-scale materials or composites for remediation of persistent organic hydrocarbon pollutants (such as monocyclic and polycyclic aromatic hydrocarbons, MAH/PAH) has generated great interest and continues to grow almost unabated. However, the usefulness and potency of these materials or conjugates hinges over several key barriers, including structural assembly with fine-tuned control over nanoparticle/biomolecule ratio, spatial orientation and activity of biomolecules, the nano/bio-interface strategy and hierarchical architecture, water-dispersibility and long term colloidal stability in environmental media, and non-specific toxicity. The present review thus critically analyses, discusses and interprets recently reported attempts and approaches to functionalize nanoparticles with biomolecules. Since there is no comprehensive and critical reviews on the applications of nanotechnology in bioremediation of MAHs/PAHs, this overview essentially captures the current global scenario and vision on the use and future prospects of biofunctionalized nanomaterials with respect to their strategic interactions involved at the nano/bio-interface essential to understand and decipher the structural and functional relationships and their impact on persistent hydrocarbon remediation.
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http://dx.doi.org/10.1016/j.jenvman.2019.109913DOI Listing
February 2020

Consolidated bioprocessing of wastewater cocktail in an algal biorefinery for enhanced biomass, lipid and lutein production coupled with efficient CO capture: An advanced optimization approach.

J Environ Manage 2019 Dec 16;252:109696. Epub 2019 Oct 16.

Department of Civil and Environmental Engineering, The Faculty of Engineering, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.

We present a holistic approach in establishing a successful green integrated bio-refinery system with improved biomass, lipid and lutein productivity, while remediating wastewater and sequestering CO with potential biodiesel and healthcare applications. To achieve this we evaluated the effect of four process parameters: CO% supply; acetate concentration; poultry litter waste (PLW) concentration; and light intensity on cultivation of Chlorella minutissma following the Taguchi's design of experimental technique. A four factors, three levels orthogonal array was adopted to cultivate Chlorella minutissma in specially developed waste water medium. Effect of the process parameters on biomass productivity, CO fixation rate, lipid content, lutein productivity and bioremediation capacity were determined. Results obtained from individual parametric combinations and Signal/Noise (S/N) ratio responses indicated S3 (5% CO, 100 mg L of acetate, 10 g L of poultry litter, and 15, 000 lux of light intensity) combination as the optimum cultivation condition. Following the S3 combination a significant enhancement in biomass productivity (292 mg L d) with exceedingly high CO fixation rate and photosynthetic efficiency (51.51 g L d of CO; P.E: 15.81%) was achieved. A maximum of 169.29 mg L d of lipid with a balanced distribution of saturated and unsaturated fatty acids conformed to the international standard for biodiesel was achieved. Additionally, 7.21 mg L d of lutein productivity was also accomplished within 7 day of cultivation, while remediating up to 93-90% of nitrogenous and phosphate substrates. Statistically, the results reinforced our findings with the S/N responses and experimental observations for a particular property.
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http://dx.doi.org/10.1016/j.jenvman.2019.109696DOI Listing
December 2019

A biorefinery for valorization of industrial waste-water and flue gas by microalgae for waste mitigation, carbon-dioxide sequestration and algal biomass production.

Sci Total Environ 2019 Oct 6;688:129-135. Epub 2019 Jun 6.

Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India. Electronic address:

Massive industrialization all over the globe is the main cause for the generation of huge quantity of wastes such as flue gas and wastewaters. Mindless release of these hazardous wastes into the environment is threatening the health and survival of the mankind. Judicious use of these wastes for microalgal biomass cultivation is recognized as a plausible approach for the creation of a renewable and sustainable process chain for biofuel production. This study was designed to cultivate microalgae utilizing the organic and inorganic nutrients from the industrial wastewater (IWW) and coal-fired flue gas (FG) for simultaneous waste bio-remediation and biomass production for biorefinery application in closed photobioreactors. The two microalgae, Chlorella sp. and Chlorococcum sp. were cultivated in industrial wastewater where varying concentrations of coal-fired FG from 1 to 10% CO, volume/volume percent (v/v) was supplied to stimulate the mixotrophic growth. Performance of the two microalgae was evaluated in terms of nutrient removal (ammonium, nitrate, phosphate and COD), CO fixation, total lipid and carbohydrate content obtained in the integrated mode of process development. The IWW with flue gas (5% CO (v/v)) resulted in maximum growth and CO fixation. The highest biomass growth (1.52 g L) and CO fixation (187.65 mg L d) of Chlorella sp. with nutrient removal of >70% was observed by 5th day of batch cultivation. Nearly 90% removal of nitrogen resulted in nutrient limitation condition that steered the accumulation of lipid (17-34%) and carbohydrate (21.5-23.1%) in Chlorella and Chlorococcum sp. An overall 1.7 fold improvement in biomass was observed in this process integration compared with control culture. The present study presents a green process for waste remediation, CO fixation and production of biomass rich in lipid & carbohydrate content for the development of a green microalgal biorefinery.
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http://dx.doi.org/10.1016/j.scitotenv.2019.06.024DOI Listing
October 2019

Electrodeposited functionally graded coating inhibits Gram-positive and Gram-negative bacteria by a lipid peroxidation mediated membrane damage mechanism.

Mater Sci Eng C Mater Biol Appl 2019 Sep 29;102:623-633. Epub 2019 Apr 29.

School of Nanoscience and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India; Department of Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India. Electronic address:

The current work deals with a time-dependent study to track the antibacterial action of electrodeposited Cu, Cu-SiC functionally graded coating (FGC) against Escherichia coli NCIM 2931 (Gram-negative) and Bacillus subtilis NCIM 2063 (Gram-positive). After 24 h of incubation, the Cu, Cu-SiC FGC causes 7 Escherichia coli NCIM 2931 and 10 Bacillus subtilis NCIM 2063 log reduction of planktonic cells. The outer membrane permeabilization experiment proves that the intake of excessive Cu ions leads to the damage of bacterial cell membrane followed by lipid degradation. The thiobarbituric acid reactive substances assay reveals that Cu ions released from the surface of Cu, Cu-SiC FGC triggers the oxidative degeneration of phospholipids (most abundant constituent of bacterial cell membrane). This was further cross-verified using atomic absorption spectroscopy. From 0 to 24 h, the bacterial morphology is characterized using transmission electron microscope and scanning electron microscope which shows the cytoplasmic leakage and cell death. The Cu, Cu-SiC FGC also exhibits hydrophobic surface (contact angle of 144°) which prevents the bacterial adherence to the surface and thus, inhibits them to penetrate into its bulk. The observed results of antibacterial and anti-adhesion properties of Cu, Cu-SiC FGC are compared with single-layered metallic Cu and Cu-SiC nanocomposite coatings. Hence, the electrodeposited Cu, Cu-SiC FGC has the potential to serve as an inexpensive touch surface alternative for the healthcare industries.
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http://dx.doi.org/10.1016/j.msec.2019.04.087DOI Listing
September 2019

Strategic valorization of de-oiled microalgal biomass waste as biofertilizer for sustainable and improved agriculture of rice (Oryza sativa L.) crop.

Sci Total Environ 2019 Sep 16;682:475-484. Epub 2019 May 16.

Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal 721302, India. Electronic address:

Intensive use of chemical fertilizer results in environmental pollution that disturbs the local ecosystem and causes reduction in the long-term crop yield. There is a need to explore the alternative source of plant nutrition such as de-oiled microalgal biomass as biofertilizer for sustainable production of food crops in a relatively pollution free environment. This study reports sustainable and improved agriculture of rice crop (cv. IR 36) by valorizing de-oiled microalgal biomass waste (DOMBW) of Scenedesmus sp., as eco-friendly fertilizer. The microalga (MA) was cultivated in open raceway pond using wastewater and flue gas. Performance evaluation and comparison of DOMBW with respect to growth and yield of rice plants vis-à-vis commercial chemical fertilizers (CF) and vermicompost (VC) applied individually or together, established the superiority of the former. The experiment comprised of five nutrient management treatments (CF, VC, MA, MA+CF and MA+VC) meeting 100% nitrogen (N) recommendation either through a single source or combined application in the soil. Combining the application of microalgal based organic fertilizer with chemical fertilizer (MA+CF), showed the highest performance in terms of plant height, tiller number, biomass, and grain yield. At the harvest stage, MA+CF also resulted in maximum plant dry weight, panicle weight, and 1000-grain weight in comparison to other treatments. This study revealed that the application of DOMBW as a biofertilizer is potentially sustainable and effective in improving the yields of rice crop with reduced use of chemical fertilizer.
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http://dx.doi.org/10.1016/j.scitotenv.2019.05.123DOI Listing
September 2019

Design of 5-fluorouracil (5-FU) loaded, folate conjugated peptide linked nanoparticles, a potential new drug carrier for selective targeting of tumor cells.

Medchemcomm 2019 Apr 12;10(4):559-572. Epub 2019 Mar 12.

Infectious Diseases and Immunology Division , CSIR-Indian Institute of Chemical Biology , Kolkata , India . Email:

In the present investigation folate peptide (FA-Pep) conjugated 5-fluorouracil (5-FU) loaded nanoparticles were synthesized and their tumor targeting potentiality was monitored by different and techniques. FA-Pep-1 and FA-Pep-2 were synthesized and radiolabeled with Tc(CO)(HO). Tc(CO)-FA-Pep-1 exhibited promising tumor uptake in an model (nude mice bearing HeLa cell xenograft and Balb/c mice bearing B16F10 melanoma tumor) as compared to Tc(CO)-FA-Pep-2. FA-Pep-1 was then conjugated with 5-FU-NPs (118 ± 4.3), as confirmed by the XPS study. These showed promising cytotoxic and apoptotic potential in B16F10 cell lines as compared to free 5-FU and unconjugated 5-FU-NPs. biodistribution and gamma-scintigraphy showed good accumulation of peptide conjugated NPs in the tumor region. Therapeutic efficacy studies in B16F10 tumor xenografts also exhibited substantial tumor growth inhibition. The above studies reveal that folate peptide conjugation may facilitate the tumor-targeting approach of 5-FU-NPs.
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http://dx.doi.org/10.1039/c8md00565fDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6482664PMC
April 2019

Performance evaluation of an outdoor algal biorefinery for sustainable production of biomass, lipid and lutein valorizing flue-gas carbon dioxide and wastewater cocktail.

Bioresour Technol 2019 Jul 16;283:198-206. Epub 2019 Mar 16.

Department of Biotechnology, Indian Institute of Technology, Kharagpur, West Bengal 721302, India.

We evaluated wastewater remediation and CO utilization potential of Chlorella minutissima from flue gas in a raceway pond, while synthesizing lutein and lipid for potential healthcare and biofuel application. A mix of 20% kitchen waste, 10 g L of poultry litter waste and 5% flue gas was maintained while cultivating the microalga. Complete removal of nitrate, nitrite and ammonium, 85% carbon and 91% phosphorus was observed. An average areal biomass productivity of 4.06 ± 0.12 g m day with a specific growth rate of 0.34 ± 0.03 day was observed within 9 days. Biomass productivity of 6.21 ± 0.16 g m day with a specific growth rate of 0.34 ± 0.03 day was achieved during winter. Furthermore, lipid content with appropriate fatty acid composition 1.04:1 (saturation:unsaturation) increased from 25% to 58%. Additionally, lutein productivity of 1.2 ± 0.08 mgL day, while utilizing 80.74 ± 0.07 mg L day of CO from 5% flue gas was obtained.
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http://dx.doi.org/10.1016/j.biortech.2019.03.075DOI Listing
July 2019

Zero-waste algal biorefinery for bioenergy and biochar: A green leap towards achieving energy and environmental sustainability.

Sci Total Environ 2019 Feb 2;650(Pt 2):2467-2482. Epub 2018 Oct 2.

Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal 721302, India.

In spite of tremendous efforts and huge investments on resources, biodiesel from oleaginous microalgae has not yet become a commercially viable and sustainable alternative to petro-diesel. This is mainly because of the technological and economic challenges hovering around large scale cultivation and downstream processing of algae, water and land usage, stabilized production technology, market forces and government policies on alternative energy and carbon credits. This review attempts to capture and analyse the global trends and developments in the areas of biofuel and bio-product of microalgae and proposes possible strategies that can be adopted to produce biofuel, biochar and bio-products utilizing wastewater in a bio-refinery model. The strategies include "Zero waste discharge" concept with process integration, wherein microalgae is grown strategically using different wastewater combined with flue gas in cultivation system for simultaneous production of 'high-value-low-volume' product and 'low-value-high-volume' product with sharing of the remnant biomass to produce biochar. In addition, the CO present in the atmosphere is captured and sequestered long term in the form of biochar would help to attain carbon negativity, while remediating wastewater and balancing energy requirements. Therefore, "Zero waste discharge" concept holds the potential to make the process a sustainable one, while gaining on the carbon credits.
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http://dx.doi.org/10.1016/j.scitotenv.2018.10.002DOI Listing
February 2019

N-Acetyl-D-glucosamine Production by a Chitinase of Marine Fungal Origin: a Case Study of Potential Industrial Significance for Valorization of Waste Chitins.

Appl Biochem Biotechnol 2019 Jan 2;187(1):407-423. Epub 2018 Jul 2.

Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India.

Chitin is a linear homo-polymer of N-acetyl-D-glucosamine (GlcNAc) and the second most abundant biopolymer after cellulose. Several industries rely on the bioprocesses for waste chitin recycle and hydrolysis by chitinase (EC 3.2.1.14) for potential healthcare applications through the production of its monomeric subunit, GlcNAc. In the present study, a chitinase-producing fungus (named as MFSRK-S42) was isolated from the marine water sample of North Bay of the Andaman and Nicobar Islands. It was identified as Aspergillus terreus by morphological and molecular characterization methods leveraging the internal transcribed spacer between 18S rRNA and 5.8S rRNA. Chitinase that was isolated from the fermentation broth of marine Aspergillus terreus was used to carry out biotransformation of chitineaceous wastes. Prior to the enzymatic hydrolysis step, chitins from different sources were characterized for the presence of characteristic functional groups, grain size distribution, and surface morphology. Enzymatic hydrolysis of 50 mg/ml substrate with six units of enzyme incubated for 5 days revealed 15, 36.5, 40, and 46 mg/ml GlcNAc production from ground prawn shell, chitin flakes, colloidal prawn shell, and swollen chitin respectively under standardized conditions, as determined by HPLC. In this study, 30, 73, 80, and 92% GlcNAc yields were observed from ground prawn shell, chitin flakes, colloidal prawn shell, and swollen chitin conversion respectively. The HPLC-eluted product was confirmed as GlcNAc by the presence of characteristic functional groups in FTIR and 244 Da molecular weight peak in HRMS analyses.
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http://dx.doi.org/10.1007/s12010-018-2822-3DOI Listing
January 2019

Quorum sensing inhibitory activity of the metabolome from endophytic Kwoniella sp. PY016: characterization and hybrid model-based optimization.

Appl Microbiol Biotechnol 2018 Sep 22;102(17):7389-7406. Epub 2018 Jun 22.

Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.

Quorum sensing, the microbial communication system, is gaining importance as a therapeutic target against pathogens. The two key reasons for the rising demand of quorum sensing (QS) inhibitory molecules are low selective pressure to develop resistance by pathogens and possibility of more species-specific effects. Due to complex interactions in a unique niche of live plant tissues, endophytes, as a survival mechanism, potentially produce various bioactive compounds such as QS inhibitors. We report the isolation of an endophytic fungus Kwoniella sp. PY016 from the medicinal plant "Bahera" (Terminalia bellirica), which exhibits substantial quorum sensing inhibition and anti-biofilm activities against the standard test organism, Chromobacterium violaceum. Sugar, sugar alcohol, carboxylic acid, lipid, and phenolic classes of metabolites (predominantly xylitol) are responsible components of the metabolome for the desired bioactivity. A judicious combination of single-factor-at-a-time strategy and artificial neural network modeling combined with genetic algorithm was employed for the selection and optimization of the critical process and medium parameters. Through this newly adopted hybrid model-based optimization, the quorum sensing inhibitory activity of the endophytic metabolome was increased by ~ 30%. This is the first report on optimization of QS inhibitory activity from any fungal endophyte using such a hybrid advanced approach.
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http://dx.doi.org/10.1007/s00253-018-9168-1DOI Listing
September 2018

Process optimization involving critical evaluation of oxygen transfer, oxygen uptake and nitrogen limitation for enhanced biomass and lipid production by oleaginous yeast for biofuel application.

Bioprocess Biosyst Eng 2018 Aug 20;41(8):1103-1113. Epub 2018 Apr 20.

Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India.

Lipid accumulation in oleaginous yeast is generally induced by nitrogen starvation, while oxygen saturation can influence biomass growth. Systematic shake flask studies that help in identifying the right nitrogen source and relate its uptake kinetics to lipid biosynthesis under varying oxygen saturation conditions are very essential for addressing the bioprocessing-related issues, which are envisaged to occur in the fermenter scale production. In the present study, lipid bioaccumulation by P. guilliermondii at varying C:N ratios and oxygen transfer conditions (assessed in terms of ka) was investigated in shake flasks using a pre-optimized N-source and a two-stage inoculum formulated in a hybrid medium. A maximum lipid concentration of 10.8 ± 0.5 g L was obtained in shake flask study at the optimal condition with an initial C:N and ka of 60:1 and 0.6 min, respectively, at a biomass specific growth rate of 0.11 h. Translating these optimal shake flask conditions to a 3.7 L stirred tank reactor resulted in biomass and lipid concentrations of 16.74 ± 0.8 and 8 ± 0.4 g L. The fatty acid methyl ester (FAME) profile of lipids obtained by gas chromatography was found to be suitable for biodiesel application. We strongly believe that the rationalistic approach-based design of experiments adopted in the study would help in achieving high cell density with improved lipid accumulation and also minimize the efforts towards process optimization during bioreactor level operations, consequently reducing the research and development-associated costs.
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http://dx.doi.org/10.1007/s00449-018-1939-7DOI Listing
August 2018

Resensitization of Akt Induced Docetaxel Resistance in Breast Cancer by 'Iturin A' a Lipopeptide Molecule from Marine Bacteria Bacillus megaterium.

Sci Rep 2017 12 11;7(1):17324. Epub 2017 Dec 11.

School of Medical Science & Technology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.

Development of the resistance is the major problem in cancer therapy. Docetaxel is a taxol alkaloid that is frequently used in metastatic breast cancer. However, resistance often limits the usefulness of this drug in many breast cancer patients. Manipulation of resistant cells to re-sensitize to the therapeutic effect of docetaxel is current strategy to overcome this problem. Here, we have introduced 'Iturin A' as a potent chemosensitizer in docetaxel resistant breast cancer cells. Combination of Iturin A and docetaxel treatment significantly hampered the proliferation of docetaxel resistant MDA-MB-231 and MDA-MB-468 breast cancer cells. Cell cycle analysis also showed massive amount of apoptotic population (Sub G0/G1) in combination therapy. A number of apoptotic and anti-apoptotic proteins were significantly altered in dual drug treated groups. Caspase 3 dependent cell death was observed in dual treatment. Molecular mechanism study showed that over-expression of Akt and its downstream signaling pathway was associated with docetaxel resistance. Iturin A significantly reduced Akt signaling pathway in resistant cells. This mechanistic action might be the reason behind the chemo-sensitization effect of Iturin A in docetaxel resistant breast cancer cells. In conclusion, Iturin A resensitized the resistant breast cancer cells to docetaxel therapy by inhibiting Akt activity.
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http://dx.doi.org/10.1038/s41598-017-17652-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5725499PMC
December 2017

Lignocellulosic biorefinery as a model for sustainable development of biofuels and value added products.

Bioresour Technol 2018 Jan 27;247:1144-1154. Epub 2017 Sep 27.

Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal 721302, India.

A constant shift of society's dependence from petroleum-based energy resources towards renewable biomass-based has been the key to tackle the greenhouse gas emissions. Effective use of biomass feedstock, particularly lignocellulosic, has gained worldwide attention lately. Lignocellulosic biomass as a potent bioresource, however, cannot be a sustainable alternative if the production cost is too high and/ or the availability is limited. Recycling the lignocellulosic biomass from various sources into value added products such as bio-oil, biochar or other biobased chemicals in a bio-refinery model is a sensible idea. Combination of integrated conversion techniques along with process integration is suggested as a sustainable approach. Introducing 'series concept' accompanying intermittent dark/photo fermentation with co-cultivation of microalgae is conceptualised. While the cost of downstream processing for a single type of feedstock would be high, combining different feedstocks and integrating them in a bio-refinery model would lessen the production cost and reduce CO emission.
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http://dx.doi.org/10.1016/j.biortech.2017.09.163DOI Listing
January 2018

Oleoyl-Chitosan-Based Nanofiber Mats Impregnated with Amniotic Membrane Derived Stem Cells for Accelerated Full-Thickness Excisional Wound Healing.

ACS Biomater Sci Eng 2017 Aug 19;3(8):1738-1749. Epub 2017 Jul 19.

Department of Gynaecology, Midnapore Medical College, Paschim Medinipur 721101, India.

Wound healing management is a major challenge for critical full-thickness skin wounds. Development of nanofibrous scaffolds with tunable wettability, degradation, and biocompatibility are highly desirable. Herein, we demonstrated synthesis of oleoyl chitosan (OC) by grafting monounsaturated fatty acid residue, C oleoyl chain, to the backbone of chitosan molecule and blending with gelatin to form the nanofiber mats. The physicochemical properties of the nanofiber mats revealed mechanical strength, moderate surface wettability, and suitable degradation rate. The nanofibrous mats showed excellent in vitro cytocompatibility with human amniotic membrane-derived stem cells (HAMSCs) in terms of enhanced adhesion and proliferation owing to biomimetic nanoarchitecture and chemical cues. Furthermore, the fabricated nanofiber was implanted with and without preseeded HAMSCs in the full-thickness wound to evaluate the skin wound healing efficacy in a rat model. Histological and immunohistochemical studies were conducted to evaluate the plausible changes of tissue architecture and expression of molecular markers involved in wound healing process. Both acellular and HAMSCs incorporated cellular nanofibers promoted wound contraction remarkably with superior skin tissue regeneration in terms of enhanced collagen synthesis, re-epithelialization and initiation of epithelial cells stratification compared to control group.
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http://dx.doi.org/10.1021/acsbiomaterials.7b00189DOI Listing
August 2017

Biosurfactant-biopolymer driven microbial enhanced oil recovery (MEOR) and its optimization by an ANN-GA hybrid technique.

J Biotechnol 2017 Aug 10;256:46-56. Epub 2017 May 10.

Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India. Electronic address:

A lipopeptide biosurfactant produced by marine Bacillus megaterium and a biopolymer produced by thermophilic Bacillus licheniformis were tested for their application potential in the enhanced oil recovery. The crude biosurfactant obtained after acid precipitation effectively reduced the surface tension of deionized water from 70.5 to 28.25mN/m and the interfacial tension between lube oil and water from 18.6 to 1.5mN/m at a concentration of 250mgL. The biosurfactant exhibited a maximum emulsification activity (E) of 81.66% against lube oil. The lipopeptide micelles were stabilized by addition of Ca ions to the biosurfactant solution. The oil recovery efficiency of Ca conditioned lipopeptide solution from a sand-packed column was optimized by using artificial neural network (ANN) modelling coupled with genetic algorithm (GA) optimization. Three important parameters namely lipopeptide concentration, Ca concentration and solution pH were considered for optimization studies. In order to further improve the recovery efficiency, a water soluble biopolymer produced by Bacillus licheniformis was used as a flooding agent after biosurfactant incubation. Upon ANN-GA optimization, 45% tertiary oil recovery was achieved, when biopolymer at a concentration of 3gL was used as a flooding agent. Oil recovery was only 29% at optimal conditions predicted by ANN-GA, when only water was used as flooding solution. The important characteristics of biopolymers such as its viscosity, pore plugging capabilities and bio-cementing ability have also been tested. Thus, as a result of biosurfactant incubation and biopolymer flooding under the optimal process conditions, a maximum oil recovery of 45% was achieved. Therefore, this study is novel, timely and interesting for it showed the combined influence of biosurfactant and biopolymer on solubilisation and mobilization of oil from the soil.
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http://dx.doi.org/10.1016/j.jbiotec.2017.05.007DOI Listing
August 2017

Therapeutic implication of 'Iturin A' for targeting MD-2/TLR4 complex to overcome angiogenesis and invasion.

Cell Signal 2017 07 24;35:24-36. Epub 2017 Mar 24.

School of Medical Science & Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India. Electronic address:

Tumor angiogenesis and invasion are deregulated biological processes that drive multistage transformation of tumors from a benign to a life-threatening malignant state activating multiple signaling pathways including MD-2/TLR4/NF-κB. Development of potential inhibitors of this signaling is emerging area for discovery of novel cancer therapeutics. In the current investigation, we identified Iturin A (A lipopeptide molecule from Bacillus megaterium) as a potent inhibitor of angiogenesis and cancer invasion by various in vitro and in vivo methods. Iturin A was found to suppress VEGF, a powerful inducer of angiogenesis and key player in tumor invasion, as confirmed by ELISA, western blot and real time PCR. Iturin A inhibited endothelial tube arrangement, blood capillary formation, endothelial sprouting and vascular growth inside the matrigel. In addition, Iturin A inhibited MMP-2/9 expression in MDA-MB-231 and HUVEC cells. Cancer invasion, migration and colony forming ability were significantly hampered by Iturin A. Expressions of MD-2/TLR4 and its downstream MyD88, IKK-α and NF-κB were also reduced in treated MDA-MB-231 and HUVEC cells. Western blot and immunofluorescence study showed that nuclear accumulation of NF-κB was hampered by Iturin A. MD-2 siRNA or plasmid further confirmed the efficacy of Iturin A by suppressing MD-2/TLR4 signaling pathway. The in silico docking study showed that the Iturin A interacted well with the MD-2 in MD-2/TLR4 receptor complex. Conclusively, inhibition of MD-2/TLR4 complex with Iturin A offered strategic advancement in cancer therapy.
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http://dx.doi.org/10.1016/j.cellsig.2017.03.017DOI Listing
July 2017

Recent Inventions and Trends in Algal Biofuels Research.

Recent Pat Biotechnol 2016 ;10(1):30-42

Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal 721302, India.

Background: In recent times, when energy crisis compounded by global warming and climate change is receiving worldwide attention, the emergence of algae, as a better feedstock for third-generation biofuels than energy crops or plants, holds great promise. As compared to conventional biofuels feedstocks, algae offer several advantages and can alone produce a significant amount of biofuels sustainably in a shorter period to fulfill the rising demand for energy.

Objective: Towards commercialisation, there have been numerous efforts put for- ward for the development of algae-derived biofuel. This article reviews and summarizes the recent inventions and the current trends that are reported and captured in relevant patents pertaining to the novel methods of algae biomass cultivation and processing for biofuels and value-added products. In addition, the recent advancement in techniques and technologies for microalgal biofuel production has been highlighted.

Methods: Various steps involved in the production of algal biofuels have been considered in this article. Moreover, the work that advances to improve the efficiency and cost-effectiveness of the processes for the manufacture of biofuels has been presented. Our survey was conducted in the patent databases: WIPO, Spacenet and USPTO.

Results: There are still some technological bottlenecks that could be overcome by designing advanced photobioreactor and raceway ponds, developing new and low cost technologies for biomass cultivation, harvesting, drying and extraction.

Conclusion: Recent advancement in algae biofuels methods is directed toward developing efficient and integrated systems to produce biofuels by overcoming the current challenges. However, further research effort is required to scale-up and improve the efficiency of these methods in the upstream and downstream technologies to make the cost of biofuels competitive with petroleum fuels.
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http://dx.doi.org/10.2174/1872208310666160830164929DOI Listing
March 2017

An Antimicrobial Metabolite from Bacillus sp.: Significant Activity Against Pathogenic Bacteria Including Multidrug-Resistant Clinical Strains.

Front Microbiol 2015 15;6:1335. Epub 2015 Dec 15.

Department of Biological Sciences, BITS Pilani- K. K. Birla Goa Campus Goa, India.

In this study, the cell free modified tryptone soya broth (pH 7.4 ± 0.2) of Bacillus subtilis URID 12.1 showed significant antimicrobial activity against multidrug-resistant strains of Staphylococcus aureus, S. epidermidis, Streptococcus pyogenes and Enterococcus faecalis. The partially purified antimicrobial molecule was found to be resistant to extremes of pH and temperatures and also to higher concentrations of trypsin and proteinase K. The antimicrobial molecule was purified by a three-step method that included reversed-phase high performance liquid chromatography (RP-HPLC). The minimum inhibitory concentration (MIC) values were determined for 14 species of bacteria using a microbroth dilution technique. The HPLC-purified fraction showed the MICs ranging from 0.5 to 16 μg/ml for methicillin and vancomycin-resistant Staphylococcus aureus (MVRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) strains. The molecular mass of the antimicrobial compound was determined to be 842.37 Da. The same antimicrobial fraction showed negligible haemolytic activity against human red blood cells even at a concentration as high as 100 μg/ml. Because of its significant antimicrobial activity at low MIC values coupled with its non-haemolytic property, it may prove to be a novel antimicrobial lead molecule.
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http://dx.doi.org/10.3389/fmicb.2015.01335DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4678185PMC
December 2015
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