Qualification: 
Ph.D
b_sankarprasad@cb.amrita.edu

Dr. Sankarprasad Bhuniya currently serves as Research Professor at Amrita Center for Industrial Research & Innovation and Amrita Center for Excellence in Advanced Materials and Green Technologies. 

Dr. Sankarprasad Bhuniya did M. Sc. in Chemistry (1995) and Ph. D. (Polymer) from Indian Institute of Technology, Kharagpur in 2000.

He worked in Korea Basic Science Institute, Ochang, South Korea (2013-2014) prior to join in Amrita Vishwa Vidyapeetham. He did postdoctoral research in Pohang University of Science and Technology (POSTECH, 2003—2006), South Korea. He worked in the field of nucleic acid chemistry and supramolecular hydrogel. After spending short-time ( July-Dec. 2006) research at BCPS Department in Illinois institute of Technology, USA retuned to India and joined as Senior Scientist to GVK Bioscience private limited (2007-2009). Later he moved to Korea and joined as Research Professor to Korea University (2009- 2013). He has major research expertise in the field of theranostic drug delivery system for cancer therapy; biomaterials for bioimaging using fluorogenic and MRI modalities. He has published 34 research articles in peer reviewed international journal in chemistry & biomaterials with average impact factor 6.00; Scopus citation index 995 & h- index 17 and 3 patent publications.

Education

YEAR DEGREE/PROGRAM INSTITUTION
July 2000 Doctoral Degree IIT Kharagpur, India
July 1995 Postgraduate Degree IIT Kharagpur, India
May 1993 Undergraduate Degree Calcutta University, WB, India

Experience

YEAR AFFILIATION
Oct 2014 – Present Professor, Department of Chemical Engineering and Materials Science, Amrita Vishwa Vidyapeetham
Feb. 2013-Sept 2014 Division of MR Research,  Korea Basic Science Institute, S. Korea
Aug. 2009-Jan. 2013 Department of Chemistry, Korea University, S. Korea
Jan. 2007-Jul. 2009 GVK Biosciences Pvt. Ltd. India
Jul. 2006-Dec. 2006 IIT, Chicago, USA
Aug. 2003-Mar. 2006 POSTECH, S. Korea
Sept. 2001-Jul. 2003 ATIRA, Ahmedabad
Aug. 2000-Jul. 2001 Universal Agrochem. Industries, Kolkata, India

Projects

Completed Project

Ongoing Project

Research Interest

  • Theranostic prodrugs: The advances in genomics, proteomics, and bioinformatics have directed to develop new type of healthcare system to reduce the drug abuse, safety and precise treatment. In search of innovative product for health care, the term, “theranostic” gained interest in clinical science. It is an appealing formulation in combination of diagnosis and therapy to improve the biodistribution and systematic administration of therapeutic in the target place. Importantly, it could be provided clear-cut solution for long time pending diseases, namely, genetic diseases and oncogenic diseases. Present needs motivated us to develop “theranostic” as future of personalized healthcare.  
  • Molecular Sensor (Chemo-sensors & bio-sensors): To understand the chemical transformation at the molecular level in the cellular milieus is challenging and it motivates the chemist to search new way to learn the biological system. Thus bio-inspired emerging strategy for fluorescent based bio-imaging is to sort and identify the species of interest within this complex microenvironment by exploiting differences in molecular reactivity.
  • MRI Contrast Agent: Magnetic resonance imaging is widely used as clinical imaging tools which provide noninvasive three dimensional spatial images of hard and soft tissues as well. Clinically, one third cases gadolinium based contrast agents are used to enhance image contrast. Presently contrast agents are incapable to provide brighter images under higher magnetic field scanner as because of high tumbling motion, mono hydration number of gadolinium complex. Additionally, the conventional MRI contrast agents are incapable to give meaningful information on various metabolic irregularities which are being associated with various diseases etc. Thus, challenge has been focused to develop gadolinium/manganese based T1 MR Contrast agent which can provide information / interrogate on metabolic process.

Research Publication

Publications: 57 (published/accepted) (Citation 2210); h-index: 23)

Year of Publication
Title

2019

A. Podder, Koo, S., Lee, J., Mun, S., Khatun, S., Kang, H. - G., Bhuniya, S., and Kim, J. Seung, “A Rhodamine based Fluorescent Probe Validates Substrate and Cellular Hypoxia Specific NADH Expression”, Chem Commun (Camb), vol. 55, no. 4, pp. 537-540, 2019.[Abstract]

Herein, we report a rhodamine-based redox probe (MQR) to visualize cytosolic NADH in the cellular milieu. Its high sensitivity and selectivity allowed it to track the alteration of the NADH level under metabolic perturbation, suggesting its potential as a useful tool to study the association between the NADH level and metabolic abnormalities with clinical significance.

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2019

K. Naidu Bobba, Anupama Binoy, Koo, S., Nedungadi, D., Podder, A., Sharma, A., Dr. Nandita Mishra, Kim, J. Seung, and Bhuniya, S., “Direct readout protonophore induced selective uncoupling and dysfunction of individual mitochondria within cancer cells”, Chemical Communications, vol. 55, no. 45, pp. 6429-6432, 2019.[Abstract]

Concurrently, manipulation of mitochondrial activity and its monitoring have enormous significance in cancer therapy and diagnosis. In this context, a fluorescent probe MitoDP has been developed for validating H2S mediated protonophore (2,4-dinitrophenol, DNP) induced mitochondrial membrane potential change, ROS formation and ATP depletion in cancer cells. The extent of protonophore activation for mitochondrial dysfunction is monitored through fluorescence signalling at 450 nm. The current study provides a proof for the concept of endogenous H2S-mediated controlled and spatial release of bioactive agents, or toxins specifically in mitochondria of cancer cells.

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2019

K. Naidu Bobba, Saranya, G., Sujai, P. T., Joseph, M. M., Velusamy, N., Podder, A., Maiti, K. Kumar, and Bhuniya, S., “Endogenous H2S-Assisted Cancer-Cell-Specific Activation of Theranostics with Emission Readout”, ACS Applied Bio Materials, vol. 2, no. 3, pp. 1322–1330, 2019.[Abstract]

Realizing the importance of activation of the anticancer drug, its distribution, and for cancer management, a new theranostic probe has been developed. Endogenous H2S stimulated the theranostic molecular prodrug (TP-HS) which is activated in cancer cells; it monitors the actual time of formation of therapeutic agent SN-38 in cellular milieu through fluorescence imaging. Upon exposure to H2S in a similar physiological condition, the azide functionality converted to amine (−NH2) in TP-HS which allows self-immolative scission of the labile benzyl-carbonate moiety for release of rhodol and SN-38 in a concerted manner. Thus, an intense emission band centered at 548 nm has appeared for quantifying the active therapeutic component. The fluorescence image revealed that the TP-HS preferentially releases rhodol and SN-38 in colon cancer (HCT116 cells) and lung cancer cells (A549 cells) compared to normal human fibroblast cells (WI-38). Further, the dose-dependent antiproliferative activity of TP-HS against various cells supports that TP-HS releases SN-38 based on endogenous H2S in cancer cells followed by its apoptotic progression monitored by (a) live–dead, i.e., acridine orange–ethidium bromide double staining assay, (b) APOPercentage apoptotic assay, and (c) Annexin V-FITC staining by flow cytometry. The theranostic prodrug TP-HS showed anticancer efficacy via the desirable apoptotic pathway. It is the first demonstration of a strategic theranostic molecular prodrug system that could be delivered chemotherapeutically with validating the real-time activation of chemotherapy in the cancer cells without the support of a cancer-directing ligand.

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2019

S. Bhuniya and Hong, K. Soo, “Diagnostic Significance of pH-Responsive Gd3+-Based T1 MR Contrast Agents”, Investigative Magnetic Resonance Imaging, vol. 23, no. 1, pp. 17–25, 2019.[Abstract]

We discuss recent advances in Gd-based T1-weighted MR contrast agents for the mapping of cellular pH. The pH plays a critical role in various biological processes. During the past two decades, several MR contrast agents of strategic importance for pH-mapping have been developed. Some of these agents shed light on the pH fluctuation in the tumor microenvironment. A pH-responsive self-assembled contrast agent facilitates the visualization of tumor size as small as 3 mm3. Optimization of various parameters is crucial for the development of pH-responsive contrast agents. In due course, the new contrast agents may provide significant insight into pH fluctuations in the human body.

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2018

K. N. Bobba, Saranya, G., Alex, S. M., Velusamy, N., Maiti, K. K., and Bhuniya, S., “SERS-active multi-channel fluorescent probe for NO: Guide to discriminate intracellular biothiols”, Sensors and Actuators, B: Chemical, vol. 260, pp. 165-173, 2018.[Abstract]

We explored a rational design and synthesis of a Raman-active small molecular fluorescent probe (S1/Int-1) to acquire multicolor fluorescence-images based on intracellular nitric oxide (NO) in cancer cells. A new UV–vis absorption band centered at λab 510 nm for S1 was appeared in the presence of NO. Similarly, with increasing concentration of NO, the emission signal centered at 527 nm increased gradually. The probe S1 reacted with NO to form benzotriazole derivative Int-1 which showed characteristic intense Raman band centered at 1440 cm-1 for –N[dbnd]N-. Individually, GSH and Cys reacted with Int-1 to offer a pair of new fluorophore 2 and 3 with different emission band centered at λem = 482 nm and λem = 453 nm respectively. Furthermore, the non-toxic probe S1 facilitated the monitoring of intracellular NO based dual colored imaging in the green and blue channel which intern allowed differentiating the intracellular GSH and Cys levels. Moreover, its cellular “off-on-off” response in the SERS spectral mode indicates that S1 can be a noninvasive tool to detect endogenous NO, GSH/Cys. Therefore, probe (S1/Int-1) could allow us monitoring of intracellular NO formation through dual channel fluorescence imaging with synchronous discrimination of thiols. © 2017 Elsevier B.V.

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2018

A. Podder, Won, M., Kim, S., Verwilst, P., Maiti, M., Yang, Z., Qu, J., Bhuniya, S., and Kim, J. S., “A two-photon fluorescent probe records the intracellular pH through ‘OR’ logic operation via internal calibration”, Sensors and Actuators, B: Chemical, vol. 268, pp. 195-204, 2018.[Abstract]

Mapping the intracellular location and concentration of hydronium ions (H3O+) and their dynamics could be a useful diagnostic tool in modern clinical science. Current needs motivated us to develop a molecular pH probe 1, operating as a logic gate, and its analogue 2. The pyridyl moiety in 1 played a significant role in proton capture and release, in acidic to alkaline pH environments. In contrast, 2 failed to show a similar spectroscopic behavior. 1 shows emission maximum at 450 nm that is independent on the pH, with excitation at 353 nm or 410 nm in acid and alkaline pH, respectively. 1 was employed to provide input-dependent (excitation wavelength) fluorescence images in a cellular milieu to detect pH changes in cellular organelles such as lysosomes and mitochondria. Furthermore, 1 provided information on the variation of the pH in the presence of cellular ROS. 1 was also found to enable the real-time monitoring of cell acidification due to nutrient starvation, which is closely associated with mitochondrial malfunction, fusion and mitophagy processes. We envision that in due course 1 can open up new research avenues in the diagnostic sector for validating the pH in the cellular milieu. © 2018 Elsevier B.V.

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2018

S. Singha, Kim, D., Bhuniya, S., and Kumeria, T., “Fluorescence Analysis: From Sensing to Imaging.”, Journal of Analytical Methods in Chemistry, vol. 2018, p. 2654127, 2018.[Abstract]

Fluorescence sensing and imaging combined with fluorescence microscopy technology has revolutionized human ability to study and visualize complex life phenomena at the molecular level to understand the cellular events with least ambiguity. Being a simple, fast, direct detection system with real-time monitoring capability, fluorescence sensing is highly demanding for in vitro as well as in vivo analysis in the recent time. In this special issue, we aim to create a platform for introducing the recent advances in the field of fluorescence-based analysis and imaging techniques.

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2018

R. Rashmi, Divya Nedungadi, Podder, A., Dr. Nandita Mishra, and Bhuniya, S., “Monitoring of topoisomerase (I) inhibitor camptothecin release from endogenous redox-stimulated GO-polymer hybrid carrier”, Journal of Photochemistry and Photobiology B: Biology, vol. 189, pp. 14-20, 2018.[Abstract]

We have developed endogenous redox-responsive polymer conjugated GO-based hybrid nanomaterials (GO-PEGssFol-CPT) for delivery of anticancer drug camptothecin (CPT) to the cancer cells. The synthesized intermediate (PEGFol) and CPT loaded GO- PEGFol were characterized using Fourier transform infrared spectroscopy (FTIR) and H NMR. The morphological feature changes of TEM and AFM images have confirmed the loading of CPT on the nanocarrier and its release from the nanocarrier. The amount of CPT was loaded was found to be 14.2%. The extent of camptothecin (CPT) release from GO-BiotinPVA-CPT in the presence of different concentrations of glutathione (GSH) was monitored with the increase in the fluorescence intensity at λ 438 nm and UV-Vis absorbance at 366 nm. The time-dependent camptothecin (CPT) release was monitored in the presence of GSH. It was noticed that CPT was completely released from GO-PEGssFol-CPT within 45 min. This release process is free from interference by other ubiquitous analytes in the living system. The constant fluorescence intensity of GO-PEGssFol-CPT against acidic pH indicated that CPT would not be released in the extracellular region of cancer cells. Therefore, such delivery system could be used to prevent unwanted cytotoxicity to the healthy cells. The GO-PEGssFol-CPT showed higher antiproliferative activity against cervical cancer cells compared to the CPT. Thus, GO-PEGssFol-CPT can be a new material to deliver the anticancer drug to the target tumor region.

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2018

E. - J. Kim, Podder, A., Maiti, M., Lee, J. M., Chung, B. G., and Bhuniya, S., “Selective monitoring of vascular cell senescence via Β-Galactosidase detection with a fluorescent chemosensor”, Sensors and Actuators, B: Chemical-A, vol. 274, pp. 194-200, 2018.[Abstract]

A new senescence-responsive fluorescent probe (SRP) was developed for the detection of β-galactosidase activity in senescent cells. UV-absorption of t probe SRP at 495 nm was increased in the presence of β-galactosidase. Its fluorescence at λem 545 nm increased ∼27-fold upon incubation with β-galactosidase (0.1 U/mL). The SRP probe is non-toxic and highly chemoselective for β-galactosidase. The high cell viability and chemoselcivity of probe SRP offer it to be a suitable marker for assessing cell senescence in live cells. Using this probe, H2O2-induced cellular senescence of human umbilical vein cells (HUVECs) could be distinguished from normal cells based on the extent of fluorescent labeling of the cells. Moreover, it was preferentially localized in acidic lysosomes. Overall, SRP is a unique chemosensor that can provide preclinical information on cell senescence in vascular endothelial cells. © 2018 Elsevier B.V.

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2018

Y. Zhou, Maiti, M., Sharma, A., Won, M., Yu, L., Miao, L. Xi, Shin, J., Podder, A., Bobba, K. Naidu, Han, J., Bhuniya, S., and Kim, J. Seung, “Azo-based small molecular hypoxia responsive theranostic for tumor-specific imaging and therapy.”, Journal of Controlled Release, vol. 288, pp. 14-22, 2018.[Abstract]

We report herein, an azo-derivative (AzP1) of FDA approved antineoplastic drug SN-38 (irinotecan analogue) as a theranostic agent with a potential for both tumor hypoxia-specific activation and therapy. The theranostic AzP1 was found to be stable within a biologically relevant pH scale and was chemically inert towards other competitive biological analytes. However, upon treatment with rat-liver microsomes, AzP1 showed a self-calibrated fluorescence enhancement at λ = 560 nm. The cytotoxicity profile of AzP1 was tested in various cancer lines. Under hypoxic conditions, prodrug AzP1 exhibited activation to release the parent drug (SN-38) and enhanced cytotoxicity in cancer cells with concomitant fluorescence enhancement at 560 nm, which served to monitor both the drug activation and tracing purposes. The therapeutic potential of AzP1 for both tumor-specific activation and suppression of tumor weights was validated in xenograft mouse model. Collectively, the synthetic ease and hypoxia-sensitive activation along with promising therapeutic properties highlight the potential of theranostic AzPI in future cancer treatment programs.

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2018

A. Podder, Senapati, S., Maiti, P., Kamalraj, D., Jaffer, S. S., Khatun, S., and Bhuniya, S., “A ‘turn-on’fluorescent probe for lysosomal phosphatase: a comparative study for labeling of cancer cells”, Journal of Materials Chemistry B, vol. 6, no. 27, pp. 4514–4521, 2018.[Abstract]

We have described the ability of a newly synthesized fluorescent probe (LP1) to detect phosphatase activity in lysosomes in cancer cells. Probe LP1 displayed a 33-fold fluorescence intensity enhancement at λem 532 nm in the presence of phosphatase in HEPES buffer (pH 4.5). The quantum yield of probe LP1 was increased by ∼21-fold upon exposure to phosphatase at acidic pH. The probe LP1 is highly chemoselective toward phosphatase (ALP/ACP) and is insensitive to interference by ubiquitous biological analytes. The high cell adhesion property and cell viability of LP1 indicate that LP1 is biocompatible and nontoxic; these two characteristic features make it a suitable candidate for phosphatase tracking in living cells. LP1 dose-dependent fluorescence images in living cells suggested that the expression of phosphatase in cancer cells (HeLa) is 2-fold higher as compared to the normal NIH-3T3 cells. The colocalization images confirmed that LP1 was exclusively localized in lysosomes. We envision that LP1 could be a potential tool in clinical diagnosis for discriminating cancer cells from normal cells depending on the expression of phosphatase in lysosomes.

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2018

N. Velusamy, Thirumalaivasan, N., Bobba, K. Naidu, Wu, S. - P., and Bhuniya, S., “A hydrogen sulfide triggered self-immolative fluorescent probe for lysosome labeling in live cells”, New Journal of Chemistry, vol. 42, no. 3, pp. 1590–1594, 2018.[Abstract]

We developed a naphthalimide-based, lysosome-targeting, and self-immolative fluorescent probe for H2S detection. Probe LS-1 comprises a 2-formylbenzoate derivative of the 1,8-naphthalimide fluorophore. H2S forms a thiohemiacetal intermediate by reacting with the formyl group of the 2-formylbenzoate derivative, which subsequently undergoes intramolecular cyclization with the ester moiety to generate a free naphthalimide fluorophore (FL-1). The UV-vis absorbance (λabs) value of probe LS-1 at 450 nm increased in the presence of H2S. Similarly, with increasing H2S concentrations, the emission band (λem) centered at 560 nm increased gradually. The probe was found to be highly sensitive and chemoselective towards H2S compared with other biological analytes. Probe LS-1 was nontoxic and very stable across the physiological pH range. The probe LS-1 enables the detection of intracellular endogenous H2S formation in HT29 cells in lysosomes.

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2017

Y. Zhou, Bobba, K. Naidu, Lv, X. Wei, Yang, D., Velusamy, N., Zhang, J. Feng, and Bhuniya, S., “A biotinylated piperazine-rhodol derivative: a 'turn-on' probe for nitroreductase triggered hypoxia imaging”, Analyst, vol. 142, no. 2, pp. 345-350, 2017.[Abstract]

We developed a nitroreductase responsive theranostic probe 1; it comprises biotinylated rhodol in conjunction with p-nitrobenzyl functionality. The probe 1 showed a remarkable fluorescence {'}turn-on{'} signal in the presence of nitroreductase under physiological conditions. The probe is considerably stable within a wide biological pH range (6-8) and also is very sensitive toward a reducing micro-environment e.g. liver microsome. Further{,} it enables providing cellular and in vivo nematode images in a reducing microenvironment.

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2017

K. Sunwoo, Bobba, K. Naidu, Lim, J. - Y., Park, T., Podder, A., Heo, J. Seok, Lee, S. Gwan, Bhuniya, S., and Kim, J. Seung, “A bioorthogonal 'turn-on' fluorescent probe for tracking mitochondrial nitroxyl formation.”, Chemical Communications (Camb), vol. 53, no. 10, pp. 1723-1726, 2017.[Abstract]

A bioreductant-resistant 'turn-on' chemodosimetric fluorescent probe Mito-1 has been developed for the detection of mitochondrial HNO in live cells. Mito-1 enables the detection of HNO as low as ∼18 nM. It has the capability to detect both exogenous and endogenous mitochondrial HNO formations in cellular milieus by providing fluorescence images. Its two-photon imaging ability fosters its use as a noninvasive imaging tool for the detection of mitochondrial nitroxyl.

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2017

Ya Zhou, Bobba, K. Nb, Lv, X. Wa, Yang, Da, Velusamy, Nb, Zhang, J. Fc, and Bhuniya, S., “A biotinylated piperazine-rhodol derivative: A 'turn-on' probe for nitroreductase triggered hypoxia imaging”, Analyst, vol. 142, pp. 345-350, 2017.[Abstract]

We developed a nitroreductase responsive theranostic probe 1; it comprises biotinylated rhodol in conjunction with p-nitrobenzyl functionality. The probe 1 showed a remarkable fluorescence 'turn-on' signal in the presence of nitroreductase under physiological conditions. The probe is considerably stable within a wide biological pH range (6-8) and also is very sensitive toward a reducing micro-environment e.g. liver microsome. Further, it enables providing cellular and in vivo nematode images in a reducing microenvironment. © The Royal Society of Chemistry 2017.

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2017

N. Velusamy, Anupama Binoy, Bobba, K. Naidu, Nedungadi, D., Dr. Nandita Mishra, and Bhuniya, S., “A bioorthogonal fluorescent probe for mitochondrial hydrogen sulfide: new strategy for cancer cell labeling”, Chem Commun (Camb)., vol. 53, no. 62, pp. 8802-8805, 2017.[Abstract]

We report the application of a chemodosimeter {'}turn on{'} fluorescent probe for detecting endogenous H2S formation in cancer cells. Mito-HS showed a bathochromic shift in the UV-vis-absorption spectrum from 355 nm to 395 nm in the presence of H2S. Furthermore{,} it showed an [similar]43-fold fluorescence enhancement at [small lambda]em = 450 nm in the presence of H2S (200 [small mu ]M). The cancer cell-specific fluorescence imaging reveals that Mito-HS has the ability to distinguish cancer cells from normal cells based on the level of endogenous H2S formation. In due course{,} Mito-HS would be a powerful cancer biomarker based on its ability to estimate endogenous H2S formation in living cells.

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2017

K. Naidu Bobba, Won, M., Shim, I., Velusamy, N., Yang, Z., Qu, J., Kim, J. Seung, and Bhuniya, S., “A BODIPY-based two-photon fluorescent probe validates tyrosinase activity in live cells.”, Chemical Communications, vol. 53, no. 81, pp. 11213-11216, 2017.[Abstract]

Herein, we report rational design, synthesis, and application of a two-photon fluorescent probe (Tyro-1) for tracking intracellular tyrosinase activity. The chemoselective detection of tyrosinase is precluded from interference of other competitive omnipresent oxidizing entities in cellular milieu. The probe showed 12.5-fold fluorescence enhancement at λ = 450 nm in the presence of tyrosinase. The nontoxic probe Tyro-1 provides information about HO-mediated upregulation of tyrosinase through cellular imaging. Its two-photon imaging ability makes it a noninvasive tool for validating the expression of tyrosinase in the live cells.

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2017

A. Podder, Alex, S. M., Maiti, M., Maiti, K. Kumar, and Bhuniya, S., “Self-calibrated fluorescent probe resembled as an indicator of the lysosomal phosphatase pertaining to the cancer cells.”, Journal of Photochemistry and Photobiology B: Biology, vol. 177, pp. 105-111, 2017.[Abstract]

A self-calibrated fluorescent probe Lyso-Phos has synthesized followed by a straightforward synthetic pathway. Lyso-Phos acts as an indicator for lysosomal phosphatase. Its photophysical property including cellular imaging was described. Lyso-Phos showed ratiometric UV-Vis- absorption changes from λ 370nm to λ 450nm in the presence of alkaline phosphatase (ALP). On the other hand, fluorescence intensity λ 560nm of Lyso-Phos has increased around 45-fold in the presence of ALP. The probe Lyso-Phos was found to be highly chemoselective toward the phosphatase compared with other ubiquitous entities in cellular milieu. The non-toxic nature of the Lyso-phos has accounted by observing higher cell viability in prostate cancer- LnCap, fibrosarcoma HT1080 and normal mouse embryo fibroblast NIH3T3 cells. Further, the probe Lyso-Phos was utilized for tracking of cellular phosphatase in live-cells. Lyso-Phos enabled to track cellular phosphatase by the extent of fluorescence labeling of LnCap cells which showed reasonable uptake efficiency in the presence of Lyso-Phos as indicated by the intracellular fluorescence. The phosphoester bond in the probe was cleaved by intracellular alkaline phosphatase leading to turn on fluorescence of the fluorescent probe Lyso-Phos. Finally, cellular colocalization with Lyso-Tracker empowered our speculation that Lyso-Phos can track endogenous phosphatase in the lysosomes. Altogether these findings suggest that Lyso-Phos would be powerful probe to detect phosphates in cancer cells.

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2016

Y. K. Yasoda, Bobba, K. Naidu, Nedungadi, D., Dutta, D., M. Kumar, S., Kothurkar, N., Dr. Nandita Mishra, and Bhuniya, S., “GSH-responsive biotinylated poly(vinyl alcohol)-grafted GO as a nanocarrier for targeted delivery of camptothecin”, RSC Adv., vol. 6, pp. 62385-62389, 2016.[Abstract]

A water-soluble and biocompatible polymer{,} i.e. biotinylated poly(vinyl alcohol)-grafted graphene oxide (GO){,} was used as a nanocarrier for targeted delivery of anticancer drug camptothecin (CPT). The extent of CPT release in the presence of glutathione (GSH) from GO-biotinPVA-CPT was monitored by the increase in the fluorescence intensity{,} at [small lambda]max = 450 nm. The cell-specific (HeLa) antiproliferative activity of GO-biotinPVA-CPT makes it suitable to be used for targeted delivery of chemotherapeutics to cancerous cells. More »»

2016

D. Dutta, Alex, S. M., Bobba, K. Naidu, Maiti, K. Kumar, and Bhuniya, S., “New Insight into a Cancer Theranostic Probe: Efficient Cell-Specific Delivery of SN-38 Guided by Biotinylated Poly(vinyl alcohol)”, ACS Applied Materials & Interfaces, vol. 8, pp. 33430-33438, 2016.[Abstract]

An optically modulated “turn-on” theranostic prodrug TP1 has been explored and formulated with biotinylated poly(vinyl alcohol) (biotinPVA) to obtain desired pharmacokinetics. TP1, consisting of the antineoplastic camptothecin analogue SN-38, and the fluorescent dye rhodol green have been covalently conjugated through a disulfide bond. Glutathione triggering the release of drug and fluorophore has been well established by UV–vis measurements through mass spectral analysis in physiological conditions. The biocompatible biotinPVA formulated prodrug (PTP1) showed remarkably higher stability against blood serum and cell-specific activation in contrast to that of TP1. Significantly, PTP1 permits monitoring of the delivery and release of well-known topoisomerase I inhibitor SN-38 by modulating fluorescence signal at λem 550 nm within intracellular milieus. Moreover, theranostic probe PTP1 exhibited dose-dependent antiproliferative activity against receptor-positive HeLa cells, whereas it did not show such an effect against receptor-negative NIH3T3 cells. Finally, the cell-specific antiproliferative activity of PTP1 via the apoptotic pathway is an efficient approach in cancer theranostics. Thus, futuristic PTP1 could be a promising agent in which diagnostic and prognostic data will be monitored synergistically. More »»

2016

R. Kumar, Kim, E. - J., Han, J., Lee, H., Shin, W. Sup, Kim, H. Min, Bhuniya, S., Kim, J. Seung, and Hong, K. Soo, “Hypoxia-directed and activated theranostic agent: Imaging and treatment of solid tumor”, Biomaterials, vol. 104, pp. 119 - 128, 2016.[Abstract]

Abstract Hypoxia, a distinguished feature of various solid tumors, has been considered as a key marker for tumor progression. Inadequate vasculature and high interstitial pressures result in relatively poor drug delivery to these tumors. Herein, we developed an antitumor theranostic agent, 4, which is activated in hypoxic conditions and can be used for the diagnosis and treatment of solid tumors. Compound 4, bearing biotin, a tumor-targeting unit, and SN38, an anticancer drug, proved to be an effective theranostic agent for solid tumors. \{SN38\} plays a dual role: as an anticancer drug for therapy and as a fluorophore for diagnosis, thus avoids an extra fluorophore and limits cytotoxicity. Compound 4, activated in the hypoxic environment, showed high therapeutic activity in \{A549\} and HeLa cells and spheroids. In vivo imaging of solid tumors confirmed the tumor-specific localization, deep tissue penetration and activation of compound 4, as well as the production of a strong anticancer effect through the inhibition of tumor growth in a xenograft mouse model validating it as a promising strategy for the treatment of solid tumors. More »»

2016

E. - J. Kim, Bhuniya, S., Lee, H., Kim, H. Min, Shin, W. Sup, Kim, J. Seung, and Hong, K. Soo, “In Vivo Tracking of Phagocytic Immune Cells Using a Dual Imaging Probe with Gadolinium-Enhanced MRI and Near-Infrared Fluorescence”, ACS Applied Materials & Interfaces, vol. 8, pp. 10266-10273, 2016.[Abstract]

A novel dual imaging probe for in vivo magnetic resonance imaging (MRI) and optical imaging was developed by combining gadolinium (Gd)-chelating MR probe and a near-infrared (NIR) fluorophore, aza-BODIPY (AB; BODIPY = boron-dipyrromethene). This aza-BODIPY-based bimodal contrast agent (AB-BCA) showed a significant fluorescence emission around the NIR range and an enhanced longitudinal relaxivity in MR modality. The probe was easily delivered to phagocytic cells of the innate immune system, together with macrophages and dendritic cells (DCs), and presented high-performance fluorescence and MR imaging without obvious cytotoxicity. For in vivo visualization of AB-BCA using MRI and optical imaging, bone marrow-derived DCs were labeled and injected into the footpad of mice, and labeled DCs were tracked in vivo. We observed the migration of AB-BCA-labeled DCs into the lymph nodes via lymphatic vessels using NIR fluorescence and T1-weighted MR images. This dual-modality imaging probe was used for noninvasive monitoring of DC migration into lymph nodes and could be useful for investigating advanced cellular immunotherapy. More »»

2015

J. Hong Lee, Jang, J. Hee, Velusamy, N., Jung, H. Sung, Bhuniya, S., and Kim, J. Seung, “An intramolecular crossed-benzoin reaction based KCN fluorescent probe in aqueous and biological environments”, Chemical Communications, vol. 51, pp. 7709–7712, 2015.

2015

R. Kumar, Shin, W. Sup, Sunwoo, K., Kim, W. Young, Koo, S., Bhuniya, S., and Kim, J. Seung, “Small conjugate-based theranostic agents: an encouraging approach for cancer therapy”, Chemical Society Reviews, vol. 44, pp. 6670–6683, 2015.[Abstract]

The advances in genomics, proteomics, and bioinformatics have directed the development of new anticancer agents to reduce drug abuse and increase safe and specific drug treatment. Theranostics, combining therapy and diagnosis, is an appealing approach for chemotherapy in medicine which exhibits improved biodistribution, selective cancer targeting ability, reduced toxicity, masked drug efficacy, and minimum side effects. The role of diagnosis tools in theranostics is to collect the information of the diseased state before and after specific treatment. Magnetic particle-, mesoporous silica-, various carbon allotrope-, and polymer nanoparticle-based theranostic systems are well accepted and clinically significant. Currently, small conjugate-based systems have received much attention for cancer treatment and diagnosis. The structural architecture of these systems is relatively simple, compact, biocompatible, and unidirectional. In this tutorial review, we summarize the latest developments on small conjugate based theranostic agents for tumor treatment and diagnosis using fluorescence and magnetic resonance imaging (MRI). © The Royal Society of Chemistry 2015. More »»

2015

K. N. Bobba, Zhou, Y., Guo, L. E., Zang, T. N., Zhang, J. F., and Bhuniya, S., “Resorufin based fluorescent “turn-on” chemodosimeter for nitrosyl (HNO)”, RSC Advances - An international journal to further the chemical sciences, 2015.[Abstract]

A cellular responsive, highly selective fluorogenic and chromogenic chemodosimeter probe for HNO is developed. This new probe showed ∼30 fold fluorescence enhancement in the presence of HNO and is sensitive to HNO at concentrations as low as 0.02 μM. Further, it is capable of detecting HNO levels in cellular milieus as well as in live specimens e.g. C. elegans.

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2014

S. Bhuniya, Maiti, S., Kim, E. - J., Lee, H., Sessler, J. L., Hong, K. Soo, and Kim, J. Seung, “An activatable theranostic for targeted cancer therapy and imaging”, Angewandte Chemie International Edition, vol. 53, pp. 4469–4474, 2014.[Abstract]

A new theranostic strategy is described. It is based on the use of an “all in one” prodrug, namely the biotinylated piperazine-rhodol conjugate 4 a. This conjugate, which incorporates the anticancer drug SN-38, undergoes self-immolative cleavage when exposed to biological thiols. This leads to the tumor-targeted release of the active SN-38 payload along with fluorophore 1 a. This release is made selective as the result of the biotin functionality. Fluorophore 1 a is 32-fold more fluorescent than prodrug 4 a. It permits the delivery and release of the SN-38 payload to be monitored easily in vitro and in vivo, as inferred from cell studies and ex vivo analyses of mice xenografts derived from HeLa cells, respectively. Prodrug 4 a also displays anticancer activity in the HeLa cell murine xenograft tumor model. On the basis of these findings we suggest that the present strategy, which combines within a single agent the key functions of targeting, release, imaging, and treatment, may have a role to play in cancer diagnosis and therapy.

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2014

E. J. Kim, Lee, H., Hong, K. S., and Bhuniya, S., “Tumor-specific T1 MR contrast agent for metastatic liver cancer model”, World Molecular Imaging Congress. 2014.

2014

J. Kang, Bhuniya, S., Lee, H., and Hong, K. S., “Protein responsive smart MRI T1 contrast agent”, World Molecular Imaging Congress. 2014.

2014

S. Bhuniya, Kang, J., Lee, H., and Hong, K. S., “Vicinal –Dithiol-Containing Protein Responsive Smart MRI T1 Contrast Agent”, 44th Meeting of the Korea Magnetic Resonance Society. 2014.

2013

J. Hee Jang, Bhuniya, S., Kang, J., Yeom, A., Hong, K. Soo, and Kim, J. Seung, “Cu2+-Responsive Bimodal (Optical/MRI) Contrast Agent for Cellular Imaging”, Organic Letters, vol. 15, pp. 4702-4705, 2013.[Abstract]

<p>A water-soluble T1 magnetic resonance imaging contrast agent (1) has been synthesized. The bimodal contrast agent 1 responds to the Cu2+ ion in living cells by enhancing the MRI modality signal whereas the optical signal gradually drops. This dual modality probe response depends on the cellular free copper ions in RAW 264.7 cells even at the micromolar level.</p>

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2013

S. Bhuniya, Lee, M. Hee, Jeon, H. Mi, Han, J. Hye, Lee, J. Hong, Park, N., Maiti, S., Kang, C., and Kim, J. Seung, “A fluorescence off-on reporter for real time monitoring of gemcitabine delivery to the cancer cells”, Chemical Communications, vol. 49, pp. 7141-7143, 2013.[Abstract]

We present the design{,} synthesis{,} optical properties and in vitro biological assessments of the theranostic prodrug 6 in which a near IR fluorophore is conjugated with a cancer cell-directing biotin unit; further it is linked with the anti-cancer drug gemcitabine via a self-immolative spacer{,} a disulfide bond. The prodrug 6 is able to monitor drug delivery and cellular imaging.

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2013

S. Maiti, Park, N., Han, J. Hye, Jeon, H. Mi, Lee, J. Hong, Bhuniya, S., Kang, C., and Kim, J. Seung, “Gemcitabine–coumarin–biotin conjugates: a target specific theranostic anticancer prodrug”, Journal of the American Chemical Society, vol. 135, pp. 4567–4572, 2013.

2013

S. Bhuniya, Kang, J., Jang, J., S., K. ;J., and Hong, K. S., “Copper ions-induced MRI T1 contrast agent for bimodal imaging of live cell”, The 18th Annual Scientific Meeting of KSMRM (KSMRM 2013). 2013.

2012

M. Hee Lee, Kim, J. Young, Han, J. Hye, Bhuniya, S., Sessler, J. L., Kang, C., and Kim, J. Seung, “Direct fluorescence monitoring of the delivery and cellular uptake of a cancer-targeted RGD peptide-appended naphthalimide theragnostic prodrug”, Journal of the American Chemical Society, vol. 134, pp. 12668–12674, 2012.

2012

P. Junwon, Jung, J. H., Hyunseung, L., Young-Woock, N., Taik, L. Yong, Hong, K. S., Kim, J. S., and Bhuniya, S., “DTTA-Ligated uridine-quantum dot (QD) conjugate as a bimodal contrast agent for cellular imaging”, Chemical Communications, vol. 48, pp. 3218-3220, 2012.[Abstract]

A uridine-quantum dot conjugate, a contrast agent for multimodal imaging, was synthesized. Its T(1) relaxivity was 655 and 571.2 mM(-1) s(-1) per particle at 36 °C in phosphate buffered saline at 60 and 200 MHz, respectively. In vitro multimodal images confirmed its uptake by RAW 264.7 cells.

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2012

M. H. Lee, Han, J. H., Kwon, P. - S., Bhuniya, S., Kim, J. Y., Sessler, J., Khang, C., and Kim, J. S., “A hepatocyte targeting single galactose-appended naphthalimide: A tool for intracellular thiol imaging in vivo”, Journal of the American Chemical Society, vol. 134, pp. 1316-1322, 2012.

2012

J. S. Kim, Lee, S., Hong, K. S., Lee, H., Moon, H., and Bhuniya, S., “Uridine-based gadolinium complex, method for manufacturing the same, and MRI contrast agent comprising the complex”, U.S. Patent KR 2012107541.2012.

2012

M. H. Lee, Bhuniya, S., Dongbang, S., Han, J. H., Kwon, P. - S., . Y Kim, J., Sessler, J. L., Kang, C., and Kim, J. S., “Cancer targeted theranostic drug delivery by RGD appended naphthalimide moiety”, 3rd MSMLG International Conference. 2012.

2012

S. Bhuniya, park, J., Lee, H., Lim, Y. T., Hong, K. - S., and Kim, J. S., “DTTA-ligated uridine-quantum dot: A nano assembled bimodal contrast agent for cellular imaging”, 3rd MSMLG International Conference. 2012.

2012

H. Lee, Bhuniya, S., Moon, H., Kim, J. S., and Hong, K. - S., “Liver directing uridine-based paramagnetic amphiphilic T1 MRI contrast agent with high relaxivity”, Proceedings of the international society for magnetic resonance in medicine. 2012.

2011

S. Bhuniya, Moon, H., Lee, H., Hong, K. Soo, Lee, S., Yu, D. - Y., and Kim, J. Seung, “Uridine-based paramagnetic supramolecular nanoaggregate with high relaxivity capable of detecting primitive liver tumor lesions”, Biomaterials, vol. 32, pp. 6533–6540, 2011.

2011

S. Lee, Lee, J. Hong, Pradhan, T., Lim, C. Su, Cho, B. Rae, Bhuniya, S., Kim, S., and Kim, J. Seung, “Fluorescent turn-on Zn2+ sensing in aqueous and cellular media”, Sensors and Actuators B: Chemical, vol. 160, pp. 1489 - 1493, 2011.[Abstract]

A naphthalimide-based water soluble Zn2+ sensor bearing polyamino carboxylate as a metal chelating moiety was synthesized and its application for the selective detection of Zn2+ ion in 100% aqueous solution is demonstrated. The newly developed fluorescent sensor exhibits selective binding affinity towards Zn2+ and pH insensitivity in biologically relevant range. Confocal fluorescent microscopy images indicate that this probe works effectively for intracellular Zn2+ imaging with high cell permeability.

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2011

J. Feng Zhang, Lim, C. Su, Bhuniya, S., Cho, B. Rae, and Kim, J. Seung, “A Highly Selective Colorimetric and Ratiometric Two-Photon Fluorescent Probe for Fluoride Ion Detection”, Organic Letters, vol. 13, pp. 1190-1193, 2011.[Abstract]

A naphthalimide-based highly selective colorimetric and ratiometric fluorescent probe for the fluoride ion displayed both one- and two-photon ratiometric changes. Upon reaction with the F− (TBA+ and Na+ salts) anion in CH3CN as well as in aqueous buffer solution, probe 1 shows dramatic color changes from colorless to jade-green and remarkable ratiometric fluorescence enhancements signals. These properties are mechanistically ascribed to a fluoride-triggered Si−O bond cleavage that resulted in a green fluorescent 4-amino-1,8-naphthalimide.

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2011

H. Lee, Bhuniya, S., Moon, H., Lee, S., Kim, J. S., and Hong, K. - S., “Uridine-based Paramagnetic Supramolecular Nanoaggregate: a Liver Specific T1 MRI Contrast Agent with High Relaxivity”, 2011World Molecular Imaging Congress. 2011.

2010

W. Xiu Ren, Bhuniya, S., Zhang, J. Feng, Lee, Y. Hoon, Lee, S. Joong, and Kim, J. Seung, “A new fluorogenic chemodosimetric system for mercury ion recognition”, Tetrahedron Letters, vol. 51, pp. 5784 - 5786, 2010.[Abstract]

A new probe system for fluorogenic sensing of mercury ions has been designed and synthesized. It is the first intermolecular reaction-based fluorogenic chemodosimetric probe system for Hg(II) ion recognition. High and low concentrations of mercury ions gave different fluorescence responses that could easily be distinguished by the naked eye. This unique system allows detection of the concentration and presence of the mercury ion.

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2010

H. Sung Jung, Ko, K. Chul, Lee, J. Hong, Kim, S. Hoon, Bhuniya, S., Lee, J. Yong, Kim, Y., Kim, S. Jin, and Kim, J. Seung, “Rationally Designed Fluorescence Turn-On Sensors: A New Design Strategy Based on Orbital Control”, Inorganic Chemistry, vol. 49, pp. 8552-8557, 2010.[Abstract]

Herein, we explore a new strategy in the chemo-sensor field for fluorescence amplification upon binding with metal ions based on controlled participation of the nitrogen lone pair orbital. The basic architecture of the sensor entails a fluorophore, the sp2 hybridized nitrogen lone pair (-C═N-), and a chelator site referred to as the control part. Though nonplanar and nonfluorescent, compound IC1 achieved pseudo planarity from binding with Zn2+ as indicated by the increased fluorescence signal. Its other analogue (IC2) is also planar, and unlike IC1-Zn2+ was fluorescent with a lack of binding affinity to metal ions. The time-dependent density functional theory (TDDFT) calculations revealed that the fluorescence amplification was due to the blocking of the nitrogen lone pair orbital; unlikely geometrical rearrangements were insignificant. This could indicate a breakthrough concept in the future design of fluorescent turn-on sensors.

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2010

J. Feng Zhang, Bhuniya, S., Lee, Y. Hoon, Bae, C., Lee, J. Hae, and Kim, J. Seung, “Novel 2,2′-bipyridine-modified calix[4]arenes: ratiometric fluorescent chemosensors for Zn2+ ion”, Tetrahedron Letters, vol. 51, pp. 3719 - 3723, 2010.[Abstract]

Two calix[4]arene derivatives with modified bipyridine as binding sites have been designed and synthesized. Compounds 1 and 2 are the first 2,2′-bipyridine-modified calix[4]arene-based sensors that can detect Zn2+ selectively with respect to ratiometric fluorescent changes and red shift. A binuclear complex structure has been demonstrated in the binding modes of 1-Zn2+ and 2-Zn2+ complexes.

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2009

B. H. Kim, Bhuniya, S., and Park, S. M., “Biotin-Amino Acid Conjugate Useful as a Hydrogelator and Hydrogel Prepared Therefrom”, 2009.

2009

H. Jung Kim, Bhuniya, S., Mahajan, R. Kumar, Puri, iv, R., Liu, H., Ko, K. Chul, Lee, J. Yong, and Kim, J. Seung, “Fluorescence turn-on sensors for HSO4-”, Chem. Commun., pp. 7128-7130, 2009.[Abstract]

A coumarin-based derivative (1){,} a highly selective and sensitive turn-on fluorogenic probe for the detection of HSO4- ions in aqueous solution{,} has been designed and synthesized. Various spectroscopic and DFT calculations revealed that H-bonding between the phenolic -OH and imine nitrogen of 1 played a crucial role in its high selectivity for HSO4-.

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2008

Y. Jun Seo, Bhuniya, S., Yi, J. Wu, and Kim, B. Hyean, “A co-assembled probing system using the homoadenine self duplex signal”, Tetrahedron Letters, vol. 49, pp. 2701 - 2703, 2008.[Abstract]

A co-assembly system consisting of fluorescent oligodeoxynucleotide (ODN) and biotin has been developed to recognize streptavidin, and it shows a fluorescent discrimination between blue and red signals through recognizing streptavidin.

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2007

B. H. Kim, Park, S. M., and Bhuniya, S., “Biotin-amino Acid conjugates useful as a hydrogelator and hydrogel prepared there form”, 2007.

2007

H. - S. Chong, Mhaske, S., Lin, M., Bhuniya, S., Song, H. A., Brechbiel, M. W., and Sun, X., “Novel synthetic ligands for targeted \PET\ imaging and radiotherapy of copper”, Bioorganic & Medicinal Chemistry Letters, vol. 17, pp. 6107 - 6110, 2007.[Abstract]

Novel ligands, NBEA, NBPA, NETA, NE3TA, and NE3TA–Bn, were synthesized and evaluated as potential chelators of copper radioisotopes for use in targeted positron emission tomography (PET) imaging or radiation therapy. The new ligands were radiolabeled with 64Cu, and in vitro stability of the radiolabeled complexes was assessed in rat serum. Serum stability results suggest that among the ligands tested, NETA, NE3TA, and NE3TA–Bn form stable complexes with 64Cu.

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2007

Y. J. Seo, Tapadar, S., Jeong, W. Y., Kim, B. H., and Bhuniya, S., “Bulletin of the Korean Chemical Society”, 2007.

2007

Y. Jun Seo, Bhuniya, S., and Kim, B. Hyean, “Reversible sol-gel signaling system with epMB for the study of enzyme- and pH-triggered oligonucleotide release from a biotin hydrogel”, Chem. Commun., pp. 1804-1806, 2007.[Abstract]

The biotin-based low molecular weight hydrogel (G1) is able to entrap the epMB and as a consequence{,} the color of the epMB changes from green to blue; the color change depends on the state of the gelator{,} i.e. upon proceeding from sol to gel and vice versa.

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2007

X. Ma, Song, A., Bhuniya, S., Mhaske, S., and Chong, H. - S., “Generation of new chelates for targeted MRI and radio immunotherapy”, 233rd ACS National Meeting. 2007.

2006

S. Bhuniya, Seo, Y. Jun, and Kim, B. Hyean, “(S)-(+)-Ibuprofen-based hydrogelators: an approach toward anti-inflammatory drug delivery”, Tetrahedron Letters, vol. 47, pp. 7153 - 7156, 2006.[Abstract]

We have synthesized (S)-(+)-ibuprofen-based hydrogelators that feature dipeptide linkages. In aqueous media, one of these hydrogelators formed robust gels that were stable for several months. Enzyme-mediated hydrolysis offers a route toward the sustained release of this anti-inflammatory agent.

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2006

S. Bhuniya and Kim, B. Hyean, “An insulin-sensing sugar-based fluorescent hydrogel”, Chem. Commun., pp. 1842-1844, 2006.[Abstract]

We have prepared a small library of amphiphiles{,} each comprising a polar carbohydrate head group attached through an N-terminal amino acid to a nonpolar pyrene tail group. One of these derivatives is sensitive to the presence of insulin in aqueous media.

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2005

S. Rahman, Bhuniya, S., Satyananda, A. J., Gharia, M. M., and Dave, A. M., “Process for preparing acarbohydrate-based bio-degradable hydrogel”, 2005.

2005

S. Bhuniya, Park, S. Min, and Kim*, andByeang Hye, “Biotin−Amino Acid Conjugates:  An Approach Toward Self-Assembled Hydrogelation”, Organic Letters, vol. 7, pp. 1741-1744, 2005.[Abstract]

Amino acid-appended biotin hydrogelators are a new class of low-molecular-weight gelators that display remarkable gelation properties in aqueous media, including buffer solutions with variable pH.

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2004

S. M. Park, Bhuniya, S., and Kim, B. H., “Biotin based hydrogelators and their gelations”, IUPAC International Symposium and Macro-Supramolecular Architectures and Materials (MAM-04). 2004.

2003

S. Bhuniya, Rahman, S., Satyananda, A. J., Gharia, M. M., and Dave, A. M., “A novel route to synthesize allyl starch and synthesis of biodegradable hydrogel by co-polymerizing allyl modified starch with methacrylic Acid and acrylamide”, Journal of Polymer Science, 2003.

2003

S. Bhuniya and Adhikari, B., “Toughening of epoxy resins by hydroxy-terminated, silicon-modified polyurethane oligomers”, Journal of Applied Polymer Science, vol. 90, pp. 1497–1506, 2003.[Abstract]

Epoxy resins are among the most versatile engineering structural materials. A wide variety of epoxy resins are commercially available, but most are brittle. Several approaches have been used to improve the toughness of epoxy resins, including the addition of fillers, rubber particles, thermoplastics, and their hybrids, as well as interpenetrating polymer networks (IPNs) of acrylic, polyurethane, and flexibilizers such as polyols. This last approach has not received much attention; none of them have been able to suitably increase resin toughness with out sacrificing tensile properties. Therefore, in an attempt to fill this gap, we experimented with newly synthesized hydroxy-terminated silicon-modified polyurethane (SiMPU) oligomers as toughening agents for epoxy resins. SiMPU oligomers were synthesized from dimethyl dichlorosilane, poly(ethylene glycol) (weight-average molecular weight ∼ 200), and toluene 2,4-diisocyanate and characterized with IR, 1H-NMR and 13C-NMR, and gel permeation chromatography. The synthesized SiMPU oligomers, with different concentrations, formed IPNs within the epoxy resins (diglycidyl ether of bisphenol A). The resultant IPN products were cured with diaminodiphenyl sulfone, diaminodiphenyl ether, and a Ciba–Geigy hardener under various curing conditions. Various mechanical properties, including the lap-shear, peel, and impact strength, were evaluated. The results showed that 15 phr SiMPU led to better impact strength of epoxy resins than the others without the deterioration of the tensile properties. The impact strength increased continuously and reached a maximum value (five times greater than that of the virgin resin) at a critical modifier concentration (20 phr). The critical stress intensity factor reached 3.0 MPa m1/2 (it was only 0.95 MPa m1/2 for the virgin resin). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1497–1506, 2003 More »»

2002

S. Bhuniya and Maiti, S., “Heterocyclic-based epoxy-terminated structural adhesive. II. Curing, adhesive strength, and thermal stability”, Journal of applied polymer science, vol. 86, pp. 3520–3526, 2002.

2002

S. Bhuniya and Maiti, S., “Phosphorus based epoxy terminated structural adhesive 2. Curing, adhesive strength and thermal stability”, European Polymer Journal, vol. 38, pp. 195 - 201, 2002.[Abstract]

The curing behavior of phosphorus based epoxy terminated polymers was studied using diaminodiphenyl ether, diaminodiphenyl sulfone, benzophenone tetracarboxylic dianhydride and the commercial hardener of Ciba-Geigy's two-pack araldite, as curing agent. The adhesive strength of these adhesives was measured by various \{ASTM\} methods like lap-shear, peel, and cohesive tests on metal–metal, wood–wood and wood–metal interfaces. All these results were compared with the synthesized epoxy resins prepared from bisphenol-A and epichlorohydrin having the epoxy equivalent value of 0.519. The thermal stability of both the virgin resin and its cured form was also studied by thermogravimetric analysis. More »»

1999

S. Bhuniya, “Toughening of epoxy resin by oligomer”, International Conference on Chemistry and Thirty-sixth Annual Convention of Chemists. 1999.

1998

S. Maiti and Bhuniya, S., “Synthesis and characterization of a new epoxy resin”, Journal of Polymer Materials(Netherlands), vol. 15, pp. 335–341, 1998.

1998

S. Bhuniya and Maiti, S., “Synthesis and Characterization of New Epoxy Terminated Polymers”, International Journal of Polymeric Materials and Polymeric Biomaterials, vol. 42, pp. 27-37, 1998.[Abstract]

Abstract Synthesis of epoxy terminated adhesive polymers based on a proprietary trifunctional heterocyclic compounds, 4,4′-sulfone diphenol, 4,4′-thiodiphenol and epichlorohydrin was carried out by the solution polymerization process using DMAc as solvent. These polymers were characterized by viscosity measurement, elemental analysis, IR spectroscopy, 1H-NMR and 13C-NMR spectrometry and X-ray diffraction. The polymers were soluble in acetone, DMF, DMAc, HMPA, NMP and DMSO like polar solvent. More »»

Peer Reviewed International Journals (Under Review)

  1. Kim, E. J., Bhuniya, S.; Lee, H.; Kim, H. M.; Cho, J.-H.; Shin, W-S.; Kim, J. S. and Hong, K.-S.,  “Dual imaging probe with Gd-enhanced magnetic resonance and BODIPY near-infrared fluorescence , Chemical Communications (Under Review); IF: 6.718
  2. Kumar, Rajesh, Shin, W. S.; Sunwoo, K.; Kim, W. Y.; Koo, S. Bhuniya,* S. and Kim* J. S., “Small molecule based theranostic agents: an encouraging approach for cancer therapy”,  Chemical Society Reviews, (Under Review); IF: 30.425 ( review proposal accepted)

Seminars and Workshops – Invited Talks

  1. Bhuniya, S. “Enzyme responsive smart MRI T1 contrast agent”, the 2nd International Congress on MRI (ICMRI 2013) & The 19th Annual Scientific Meeting of KSMRM (KSMRM 2014), Seoul, South Korea. March 28-29, 2014.

Awards & Honors

  1. International Award: Brain Pool Fellow: National Research Foundation - Korea Republic; April 2018
  2. National eligibility Test (NET) for Lectureship & Junior Research Fellowship in Indian Universities and Colleges, conducted by Council of Industrial Research &Technology (CSIR), 1994
  3. Qualified in the Graduate Aptitude Test in Engineering (GATE) conducted by the All India Council for Technical Education, India for a fellowship, 1995; 99.51 (percentile, 10thin all India rank)

Membership in Professional Bodies

  1. Professor Sukumar Maiti Polymer Award Foundation– Life Member.
  2. The International Society of Magnetic Resonance Imaging in Medicine, Member, 2004-2015.

Student Guidance

Master’s Students

  1. “GSH  activatable graphene based anti cancer theranostic tool”, Yamini Yasoda, Department of Biomedical Engineering, 2015-2016 (Dr. Nikhil Kothurkar)