Sankha Chattopadhyay

Sankha Chattopadhyay
Variable Energy Cyclotron Centre | VECC · Department of Atomic Energy

PhD

About

75
Publications
14,433
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
988
Citations

Publications

Publications (75)
Article
(S)-5-bromo-N-[(1-cyclopropylmethyl-2-pyrrolidinyl)methyl]-2,3-dimethoxybenzamide (4) has pico-molar in vitro binding affinity to D(2) receptor (K(i) (D(2))=0.003 nM) with lower affinity to D(3) receptor (K(i) (D(3))=0.22 nM). In this study, we describe radiosynthesis of [(11)C]4 and evaluation of its binding characteristics in post-mortem human br...
Article
Molybdenum-99 of low-to-medium specific activity, 7.4-14.8 GBq/g, obtained by the (98)Mo(n,gamma)(99)Mo reaction in research reactors requires a large alumina column to adsorb the molybdenum since the capacity of alumina to adsorb Mo is limited (20 mg Mo/g of alumina). The large size of alumina column, in turn, requires large eluant volumes to elut...
Article
Many radionuclides, namely, 166Ho, 90Y, 165Dy, 32P, 198Au, 186Re, etc. have been used for radio-synovectomy. Silver-111 (T 1/2 7.45 d) can be produced in a nuclear reactor and is a potential therapeutic radionuclide decaying by beta(-) emission (92% E beta max=1.037MeV and 8% by beta(-) decay associated with emission of gamma-rays (E gamma=245.4keV...
Article
A method for the separation of no-carrier-added (nca) arsenic radionuclides from bulk amounts of irradiated germanium oxide (GeO2) target was developed in view of their potentialities in different biological and nuclear medicine applications. The beta- emitting 77As radionuclide, produced by the decay of 77Ge through the natGe(n,gamma)77Ge nuclear...
Article
Among various positron-emitting radionuclides, certain radioisotopes of Y, Sr and Rb have important applications in diagnostic and therapeutic nuclear medicine. In the present work, an attempt has been made to produce some of those radioisotopes by irradiating a natural Ge-target material with heavy-ion oxygen ((16)O(+6)) projectiles. An effective...
Article
Gallium-68 [ t 1/2 : 67.7 min, β ⁺ (89 %)] has application in PET imaging mainly for prostate cancer and neuroendocrine tumours. Gallium-68 is generally obtained from a ⁶⁸ Ge/ ⁶⁸ Ga generator. It is therefore an important task to prepare ⁶⁸ Ge ( t 1/2 = 271 days) radiochemical for the manufacture of ⁶⁸ Ge/ ⁶⁸ Ga generator to cater for the needs of...
Article
68Ga is produced from enriched zinc-68 target electrodeposited on copper base material which was irradiated with 15 MeV proton energy in 30 MeV cyclotron. A modified semi-automated separation and purification module was used to obtain pharmaceutical grade [68Ga]GaCl3 in 35 ± 5 min. The quality of [68Ga]GaCl3 produced was in accordance with Pharmeur...
Conference Paper
Full-text available
DAE Medical Cyclotron Facility at Kolkata wasinstalled by Variable Energy Cyclotron Centre. There wasa requirement to demonstrate the functioning of themachine for FDG production in the liquid target beamline. Complete wiring and control interface for thismachine was done by our team. We developed controlprograms and graphical user interface indige...
Article
A fully automated large-scale production of sodium [¹⁸F]fluoride ([¹⁸F]NaF) using SYNTHERA module with a modification in integrated fluidic processor (IFP) is reported. This modified IFP module is used to prepare [¹⁸F]NaF with more than 98% non-decay corrected radiochemical yield (RCY) within 5 min with specifications in accordance with United Stat...
Article
Background: Few nuclear reactors in the world producing high specific activity (HSA) 99Mo using enriched 235U (HEU), are aging and are planned for shut down in the near future. Further, HEU will not be freely available, due to safeguards, and the technology for 99Mo from low-enriched 235U (LEU) is not yet widely accepted since 239Pu contamination...
Article
Background The drug cinnarizine is used in the treatment of vertigo and migraine. The main drawback is its very low water solubility which causes unpredictable bioavailability. Solubility is better in acidic pH. Therefore, gastro-retentive formulation would be beneficial to improve the bioavailability of the drug. Objective The objective of the st...
Article
The aim of this work was to develop a method for purification of the spent 100/99Mo–99mTc generator free from non-isotopic impurities like Nb, Y, Zr and recovery of 99mTc using a Sephadex column and MEK solvent extraction technique, respectively. This study was done by performing simulation experiment with ⁹⁸Mo(n,γ)⁹⁹Mo solution doped with the radi...
Article
Melanoma is a highly aggressive skin cancer. Paclitaxel formulation of solid lipid nanoparticles modified with Tyr-3-octreotide (PSM) is employed to treat melanoma that highly expresses somatostatin receptors (SSTRs). PSM shows more apoptotic and anti-invasive effect in B16F10 mice melanoma cells as compared to dacarbazine (DTIC), an approved chemo...
Article
Zirconium-89 (⁸⁹Zr) is an interesting immuno-PET imaging agent due to its favorable physical characteristics of 78.4 h half-life and a relatively low positron energy of 0.9 MeV. Radiochemical separation of ⁸⁹Zr from irradiated yttrium target matrix has been achieved by different separation methodologies like anion-exchange chromatography, cation-ex...
Article
The cross-linked chitosan polymer (CCM) is an emerging adsorbent matrix. The CCM matrix has very high adsorption for Mo and thus can be utilized to prepare ⁹⁹Mo/99mTc generator using low-specific activity (n, γ) ⁹⁹Mo. The elution efficiency of 99mTc from ⁹⁹Mo/99mTc generator based on the CCM polymer oxidized and non-oxidized form has been found mor...
Book
Full-text available
This publication presents a comprehensive overview of the technologies involved in the production of cyclotron based 99mTc. These would include techniques relevant to preparation of targets, irradiation of targets under high beam currents, target processing, target recovery and quality control of the final product. The publication provides broad in...
Article
Radioactive ion beams of 111 In (indium-111, half-life 2.8 days) have been produced using the plasma sputtering method in an electron cyclotron resonance (ECR) ion source at the Variable Energy Cyclotron Centre RIB facility. Indium isotopes were first produced by bombarding a natural silver target with a 32 MeV, 40 µA alpha particle beam from the K...
Article
Gallium-68 radioisotope is an excellent source in clinical positron emission tomography application due to its ease of availability from germanium-68 (68Ge)/gallium-68 (68Ga) generator having a shelf life of 1 year. In this paper, a modified method for purification of the primary eluate of 68Ge-68Ga generator by using a small cation exchange resin...
Article
The direct production of 99mTc in cyclotrons by the proton irradiation of highly enriched 100Mo requires recovery of the costly enriched 100Mo from the irradiated target to keep the cost of 99mTc within the affordable limit. Various isotopes (both radioactive and stable) of Mo, Nb, Zr, and Y may be concomitantly produced directly or indirectly by s...
Article
Full-text available
The purpose of this study was to develop surfactant-free quercetin-loaded PLGA nanoparticles (Qr-NPs) and investigate the hepatoprotective efficacy of the product non-invasively by nuclear scintigraphy. The nanoparticles were prepared using PLGA by dialysis method and ranged in size between 50 and 250 nm with a narrow range of distribution. They we...
Article
Statement of significance: Somatostatin receptors (SSTRs) especially subtype 2 (SSTR2) are overexpressed in various mammalian cancer cells. Proliferating endothelial cells of neovasculature also express SSTR2. Tyr-3-octreotide (TOC) is a known ligand for SSTR2. We have successfully prepared paclitaxelloaded solid lipid nanoparticles modified with...
Article
The direct production of 99mTc through (p, 2n) reaction on natural molybdenum target and enriched 100Mo target was investigated. Separation of technetium radionuclide from the irradiated 100Mo target by a new method using Dowex-1 ion exchange resin as well as by the standard solvent extraction (methyl ethyl ketone) method was studied. An automated...
Article
Full-text available
In this study, metabolic stability and biological evaluation of 99mTc labelled 6-hydrazinopyridine-3-carboxylic-acid (HYNIC)-Tyr3-Octreotide was reported as a candidate for imaging somatostatin-receptor (SSTR)-positive tumors. The metabolic stability analysis did not show any evidence of breaking of the labeled compound and formation of free 99mTc....
Article
Full-text available
Performance study of a computer controlled automated closed cyclic module for the separation and recovery of 99mTc from low specific activity (n, γ) 99Mo using methyl ethyl ketone (MEK) solvent extraction technique named 99Mo/99mTc-TCM-AUTOSOLEX (Technetium automated solvent extraction) Generator is described. The entire system is automated and con...
Article
Development of molecular imaging agents to target tumor has become a major trend in nuclear medicine. With the aim to develop new potential 99mTc-radiopharmaceuticals for targeting tumor we have synthesised 5-nitroimidazolyl amino acids and RGD-coupled 2-nitroimidazoles. Technetium-99m radiolabeling with high radiochemical purity (>90%) was achieve...
Article
Full-text available
Nanoparticle biodistribution study is of great importance in bringing nanomedicine to patients. In this article, solid lipid nanoparticle (SLN) with dimension less than 100 nm was successfully radiolabelled with 99mTc by using sodium borohydride as a reducing agent (instead of stannous salts). Paclitaxel (PTX) was used as a model anticancer drug fo...
Article
Full-text available
The objective of the present study was to develop bilayer tablets of atorvastatin and atenolol that are characterized by initial fast-release of atorvastatin in the stomach and comply with the release requirements of sustained-release of atenolol. An amorphous, solvent evaporation inclusion complex of atorvastatin with β -cyclodextrin, present in 1...
Article
Full-text available
Peptides are attracting increasing interest in nuclear oncology for targeted tumor diagnosis and therapy. We therefore synthesized new cyclic octapeptides conjugated with HYNIC by Fmoc solid-phase peptide synthesis. These were purified and analyzed by RP-HPLC, MALDI mass, (1)H NMR, (13)C NMR, HSQC, HMBC, COSY and IR spectroscopy. Conformational ana...
Article
Protection of the thiolate function of the mercaptoacetyltriglycine (MAG3) by S-thiomethyl group allows automatic deprotection of the protecting group during technetium-99m radiolabelling by transchelation using stannous chloride dihydrate as reductant. Protection of the thiolate group with S-thiomethyl increases the stability of the ligand, desire...
Article
99Mo produced 99mTc (t1/2=6hr, 140keV γ-ray) is the most useful radioisotope for nuclear diagnostics. High specific activity 99Mo is supplied globally mainly by five old reactors whose routine or unscheduled maintenance shutdown causes supply irregularities that adversely affects patient management in nuclear medicine centres. 99mTc may also be pro...
Article
(61)Cu was produced by (nat)Co(α, xn)(61)Cu reaction. (61)Cu production yield was 89.5 MBq/μAh (2.42 mCi/μAh) at the end of irradiation (EOI). A simple radiochemical separation method using anion exchange resin and ascorbic acid has been employed to separate the product radionuclide from inactive target material and co-produced non-isotopic impurit...
Article
A simple and inexpensive ion-exchange chromatography method for the separation of medically useful no-carrier-added (nca) iodine radionuclides from bulk amounts of irradiated tellurium dioxide (TeO(2)) target was developed and tested using (131)I. The radiochemical separation was performed using a very small Dowex-1x8 ion-exchange column. The overa...
Article
A simple and inexpensive method has been developed for the separation of (99m)Tc from (99)Mo produced from the neutron activation of (98)Mo by (98)Mo(n,gamma)(99)Mo nuclear reaction. The recovery of (99m)Tc was performed by solid-liquid extraction based on alumina column chromatography. The overall radiochemical yield for the complete separation of...
Article
Protection of the thiol function of L,L′-EC by S-thiomethylation allowed automatic deprotection during 99mTc - chelation without the use of any additional reagents. After radiolabeling (either at pH 8.5 or > 8.5), this precursor of L,L′-EC produced the desired chelate that was compared to 99mTc L,L′-EC, the standard chelate, by HPLC, biodistributio...
Article
To synthesize and evaluate a (99m)Tc labeled fluroquinolone, moxifloxacin as a potential bacteria specific infection imaging agent. A radiolabeling formulation including moxifloxacin, [Moxicip(TM) injection, Cipla] (4mg), sodium pertechnetate and stannous chloride (5microg) gave the best radiolabeling efficiency and moderately stable labeled (99m)T...
Article
A simple and inexpensive method of separation of (99m)Tc from (99)Mo produced by neutron activation of (98)Mo via the (98)Mo(n,gamma)(99)Mo nuclear reaction is described. The recovery of (99m)Tc was performed by solvent extraction technique followed by column (active alumina) chromatography. The overall radiochemical yield for the complete separati...
Article
A simple and inexpensive method for the separation of medically useful no-carrier-added (nca) iodine radionuclides from bulk amounts of irradiated tellurium dioxide (TeO(2)) target was developed. The beta(-) emitting (131)I radionuclide, produced by the decay of (131)Te through the (nat)Te(n, gamma)(131)Te nuclear reaction, was used for standardiza...
Article
A simple separation technique of (99m)Tc from Na(2)[(99)Mo]MoO(4) in sodium hydroxide solution obtained from the (98)Mo(n,gamma)(99)Mo reaction is described. Low to medium specific activity (99)Mo-molybdate solution of 7.4-18.5GBq (200-500mCi) in sodium hydroxide was passed through a tiny Dowex-1 column (25mg) to separate the (99m)Tc from the (99)M...
Article
Full-text available
Nicotine alpha(4)beta(2) receptor subtypes are implicated in the study of Alzheimer's disease, schizophrenia, substance abuse, lung cancer, and other disorders. We report the development and evaluation of a putative antagonist, 5-(3'-fluoropropyl)-3-(2-(S)-pyrrolidinylmethoxy)pyridine (nifrolidine) as a PET agent for nicotine alpha(4)beta(2) recept...
Article
Full-text available
We have synthesized a new fluorinated dopamine D2 receptor agonist, (R,S)-2-(N-propyl-N-5'-fluoropentyl)amino-5-hydroxytetralin (5-OH-FPPAT). The radiosynthesis of the fluorine-18 analog, (18)F-5-OH-FPPAT was achieved in decay corrected yields of 10 to 15% in specific activities of approx. 1.5 to 2 Ci/micromol. In vitro binding and autoradiographic...
Article
We have synthesized a new fluorinated dopamine D2 receptor agonist, (R,S)-2-(N-propyl-N-5'-fluoropentyl)amino-5-hydroxytetralin (5-OH-FPPAT). The radiosynthesis of the fluorine-18 analog, F-18-5-OH-FPPAT was achieved in decay corrected yields of 10 to 15% in specific activities of approx. 1.5 to 2 Ci/mumol. In vitro binding and autoradiographic stu...
Article
Full-text available
Fallypride [benzamide, 5-(3-fluoropropyl)-2,3-dimethoxy-N-[(2S)-1-(2-propenyl)-2-pyrrolidinyl]methyl]-, CAS RN 166173-78-0] is a selective dopamine D2/D3 receptor antagonist. Carbon-11 labeled fallypride may serve as a radiotracer for use in biomedical imaging technique positron emission tomography (PET). The precursor, 5-(3-fluoropropyl)-2-hydroxy...
Article
99Mo of specific activity 7.4-14.8GBq (200-400mCi)/g was adsorbed on a 'jumbo' alumina column (40g, 90mm(H) x 20mm (dia.); 50g, 65mm(H) x 35mm(dia.). [99mTc]TcO4-, eluted with 50-70ml normal saline and applied to a tiny column of a strong anion exchanger, Dowex-1 x 8, 10-15 mg, 8-12 mm(H) x 1 mm(dia.). Pertechnetate was eluted from the Dowex-1 colu...
Article
Full-text available
A novel method for the recovery of (TcO4-)-Tc-99m from (n , gamma)(99) Mo using conventional anion-exchange chromatography over Dowex- 1 x 8 column, followed by elution and subsequent novel purification over AgCl-alumina column is reported. (MoO42-)-Mo-99 2- solution (7-14GBq/mg) in NaOH was passed down a Dowex- 1 x 8 column (6-7 x 2 min), collecte...
Article
99Mo of specific activity 7.4–14.8GBq (200–400mCi)/g was adsorbed on a ‘jumbo’ alumina column (40g, 90mm(H)×20mm (dia.); 50g, 65mm(H)×35mm(dia.). [99mTc]TcO4−, eluted with 50–70ml normal saline and applied to a tiny column of a strong anion exchanger, Dowex-1×8, 10–15mg, 8–12mm(H)×1mm(dia.). Pertechnetate was eluted from the Dowex-1 column with 5–6...
Article
99mTc-d,l-HMPAO, an important SPECT agent for imaging cerebral perfusion, suffers from the disadvantage of an inherent instability and its shelf life has been reported to be 30 min. The latter is a harsh constraint and not compatible with Centralized Radiopharmacy procedures. During the attempts to improve upon the stability of 99mTc-d,l-HMPAO, pre...
Article
A method of purification of [131I]mIBG (diagnostic dose) by solvent extraction and possibility of its stabilisation by storage in ethyl acetate and chloroform at up to 40 degrees C for not less than 14 days is described. In order to further enhance the utility of this finding, the organic extract was dispensed into vials and dried. Vials containing...
Article
Ethylene dicysteine (EC) and ethyl cysteinate dimer (ECD) complexes of67Ga and111In were prepared and the complexation yield and radiochemical purity estimated by paper chromatography, paper electrophoresis and solvent extraction into chloroform.111In-EC was found to be anionic, whereas111In-ECD was neutral. EC complexes of67Ga and111In were stable...
Article
A reported paper chromatographic technique has been extended to delineate the hydrolysed components in 201Tl radiopharmaceuticals for the determination of radiochemical purity. Detailed radiochemical purity analysis of 201TlCl has been demonstrated using mini paper chromatographic systems. The technique is also useful in evaluation of the radiochem...
Article
A reliable method of labelling MIBG with 131I is reported. Radioiodination involved nucleophilic exchange reaction (160 degrees C, 30 min) catalysed by directly added Cu(II) or by Cu(I) generated in situ by addition of Na2S2O5 to CuSO4. An additional step of purification of the radiolabelled MIBG by anion exchange chromatography is recommended. The...
Article
The retention and elution of Fe(III) on Dowex-50 cation exchange column in conc. HCl medium was studied using 59Fe as a tracer. Details of the retention/elution behaviour of trace quantities of 114mIn and 67Ga on Dowex-50 resin in the presence of various iron concentrations were also studied since the iron content altered the adsorption behaviour o...
Article
111In was obtained by a two-step separation procedure from an irradiated cadmium target, extending the method developed earlier by the authors for silver targets. The overall yield was 90–95% and the purity of the 111In was compatible with medical applications.
Article
An additional elution step with dilute ascorbic acid is used to remove iron from [67Ga]gallium citrate without any significant loss of 67Ga. The addition of ascorbic acid resulted in the reduction of Fe(III) to Fe(II) and quantitative elution of iron from an ion exchange column. High yield of 67Ga free from iron was obtained. The new method is a re...
Article
111In was produced by the 109Ag(α, 2n)111In reaction. A simple radiochemical separation technique, using Dowex-50 cation exchange resin (with prior removal of copper bulk, if present), has been employed to separate radioindium from inactive contaminants like Ag, Cu, Fe and active contaminant like 67Ga and 65Zn. The radiochemical separation yield wa...

Network

Cited By