Nanocrystalline zirconia: A novel sorbent for the preparation of 188W/188Re generator
Introduction
Rhenium-188 (188Re) is an attractive therapeutic radionuclide due to its reasonable half life (16.9 h), high-energy beta radiation (Eβ max=2.118 MeV), low abundance (15.8%) of 155 keV photons and convenient availability in the form of 188W/188Re generator in high specific activity. Being a congener of 99mTc, the chemistry of Re is similar to Tc, which is an additional advantage for working with molecules that have shown promising results as 99mTc-radiopharmaceuticals. The low energy (155 keV) gamma emission enables imaging for monitoring in-vivo localization and dosimetric calculations (Jeong and Knapp, 2008; Knapp, 1998). The attractive physical properties of 188Re and its production from a long-lived parent Tungsten-188 (188W, T1/2=69.2 d), from a generator with an adequate shelf-life, makes it an interesting option for clinical use. Unfortunately, 188W can be produced only by double neutron capture with low absorption cross-sections [186W(n,γ)187W (σ=37.9±0.6 b); 187W(n,γ)188W (σ=64±10 b)]. Further, owing to rather long half-life of 188W, relatively long irradiation periods are required even for the production of 188W of modest specific activity (Knapp et al., 1994a, Knapp et al., 1994b). However, 188W, from the high flux reactors (φ∼1015 n cm−2 s−1) can be used to make 188W/188Re generators to obtain ‘no carrier added’ 188Re. Most of the commercially available 188W/188Re generators are akin to the 99Mo/99mTc generators using alumina columns, where tungsten is retained on the alumina column and 188Re is eluted with 0.9% NaCl solution (Perego et al., 2007; Dadachova et al., 1995; Kamioki et al., 1994; Knapp et al., 1994; Knapp and Mirzadeh, 1994; Coursey et al., 1990; Callahan et al., 1989). However due to the low specific activity of 188W, the 188Re obtained from 188W/188Re generators is dilute with low radioactivity concentration. Consequently, it often requires an additional concentration step (Sarkar et al., 2009; Mansur et al., 2006; Jackel et al., 2005; Mushtaq, 2004; Guhlke et al., 2000; Tanase et al., 1997) for clinical applications.
Although preparation of 188W/188Re generators using alumina sorbent remains the main commercial procedure, alternative pathways such as 188W/188Re gel generators based on matrices such as zirconium or titanium tungstate (Dadachov et al., 1994, Dadachov et al., 2002; Dadachov and Lambrecht, 1995) have also been exploited. In the last few years, a number of alternative sorbents with higher capacity for W such as gel metal oxide composite, hydroxyapatite and polymeric zirconium compound (PZC), have been developed and exploited for the preparation of 188W/188Re generators (Monroy-Guzman et al., 2009; Iller et al., 2007, Iller et al., 2007; Matsuoka et al., 2005). Recently, our group (Chakravarty et al., 2009, Chakravarty et al., 2009) has demonstrated the feasibility of developing an electrochemical 188W/188Re generator. However, these recent techniques have yet to reach the commercial stage for clinical applications. Development of alternative sorbents for 188W/188Re generators still remains an interesting challenge. Thus, in the search for a novel high capacity sorbent for use in 188W/188Re generators, we carried out the work reported here.
Nanoparticles are expected to provide unprecedented opportunities to develop and hold the promise of creating new materials for chromatographic applications. One of the specific properties of nanomaterials is that a high percent of the atoms reside on the surface. These surface atoms are unsaturated, exhibit intrinsic surface reactivity and have a tendency to chemisorb charged species in aqueous solution in order to achieve surface stabilization. The potential of such nanomaterials as new generation of sorbents in the chromatographic separation of metal ions (Cumbal et al., 2003; Okuyama and Lenggoro, 2003; Sarkar et al., 2003; Vassileva and Furuta, 2001; Manning et al., 1998; Hiraide et al., 1997; Ragai and Selim, 1987) have been exploited. However, researches about the preparation of radionuclidic generators using nanoparticles are seldom reported. Keeping parity with the modern trends and to tap the potential of nanomaterials as a sorbent in the relatively unexplored field of radionuclide generators, we earlier synthesized and characterized a noble sorbent, polymer embedded nanocrystalline titania (TiP) for its possible application in the preparation of 99Mo/99mTc (Chakravarty et al., 2008) and 188W/188Re (Chakravarty et al., 2009, Chakravarty et al., 2009) generators. In this communication, we report the synthesis and characterization of nanocrystalline zirconia and its utilization as a column material in the preparation of 188W/188Re generator.
Section snippets
Chemicals
Reagents such as hydrochloric acid, ammonium hydroxide, etc. were of analytical grade and were procured from SD Fine Chemicals, Mumbai or BDH (India). Zirconyl chloride (ZrOCl2·8H2O) and isopropyl alcohol (A.R grade) were obtained from E. Merck, Mumbai, India. Stannous chloride and DMSA were obtained from Sigma Chemical Company, USA. Na2H2HEDP was obtained from Sigma (St. Louis, MO). Paper chromatography strips were purchased from M/s. Whatman, UK. Flexible silica plates (coating thickness 0.25
Results
The goal of the present study was to evaluate the merits of nanocrystalline zirconia sorbent in the preparation of 188W/188Re generator system. In order to demonstrate the reliability of this new sorbent and to validate the parameters for sorption of 188W and separation of 188Re, we have optimized various process parameters.
Discussion
The overall objective of the present work is to demonstrate the potential utility of nanocrystalline zirconia as an alternative sorbent, in the preparation of 188W/188Re generator to obtain clinical grade 188Re. The synthesis process reported here is inexpensive, simple, carried out at ambient conditions and amenable for large-scale production. All precursors of the synthesis process are commercially available. The material obtained is suitable for chromatographic applications. Initially, most
Conclusions
This investigation demonstrates that nanocrystalline zirconia is a promising sorbent with significant ion-exchange capacity for 188W and could be an attractive option for the preparation of 188W/188Re generators. The 188W/188Re generator prepared using this nanocrytalline zirconia sorbent provides carrier-free 188Re (as ) on elution with 0.9% NaCl solution, which is physiologically compatible. The sorbent was stable and the performance of the generator remained consistent over a period
Acknowledgements
The authors are grateful to Dr. V. Venugopal, Director, Radiochemistry and Isotope Group, Bhabha Atomic Research Centre for his support to this program. The authors also acknowledge Dr. V.K. Manchanda, Head, Radiochemistry Division and Dr. (Ms.) S. Ray, Head, Uranium Extraction Division of this centre for providing their facilities for the determination of zeta potential and ICP analyses respectively.
References (45)
- et al.
Polymer supported inorganic nanoparticles: characterization and environmental applications
React. Funct. Polym.
(2003) - et al.
Development of titanium tungstate-based 188W/188Re gel generator using tungsten of natural isotope abundance
Appl. Radiat. Isot.
(2002) - et al.
Collection of trace heavy metals complexed with ammonium pyrrolidinedithiocarbamate on surfactant-coated alumina sorbents
Talanta
(1997) - et al.
Development of semi-automated system for the preparation of 188Re aqueous solutions of high and reproducible activity concentrations
Appl. Radiat. Isot.
(2005) - et al.
Use of the Oak Ridge National Laboratory Tungsten-188/Rhenium-188 generator for preparation of the Rhenium-188 HDD/Lipiodol complex for trans-arterial liver cancer therapy
Semin. Nucl. Med.
(2008) - et al.
Processing of reactor-produced 188W for fabrication of clinical scale alumina based 188W/188Re generators
Appl. Radiat. Isot.
(1994) - et al.
Preparation of [186Re] Re-DMSA and its biodistribution studies
Appl. Radiat. Isot.
(1999) - et al.
Preparation, stability studies and pharmacological behavior of [186Re]Re-HEDP
Appl. Radiat. Isot.
(1999) - et al.
Effect of reaction conditions on preparations of rhenium-188 hydroxyethylidene diphosphonate complexes
Nucl. Med. Biol.
(1999) Recovery of enriched 186W from spent 188W/188Re generators
Appl. Radiat. Isot.
(1996)
Preparation of nanoparticles via spray route
Chem. Eng. Sci.
Ion exchange and surface properties of titania gels from Ti- III solutions
J. Colloid Interface Sci.
Characterization and optimization of a chromatographic process based on ethylenediamine-N,N,N′,N′-tetra(methylphosphonic) acid-modified zirconia particles
J. Chromatogr. B
Evaluation of two methods of concentrating perrhanate (188Re) eluates from 188W–188Re generator
Appl. Radiat. Isot.
A 99mTc generator using a new inorganic polymer adsorbent for (n,γ) 99Mo
Appl. Radiat. Isot.
Preparation of homodispersed nano zirconia
Powder Technol.
Preparation, biodistribution and dosimetry of 188Re(V)-DMSA in patients with disseminated bone metastases
Nucl. Med. Commun.
Rhenium-188 from therapeutic application from an alumina based tungsten-188/rhenium-188 radionuclide generator. A radionuclide generator system based on sorption of 188W sodium or potassium tungstate on alumina gives good yields of 188Re for radiolabeling of therapeutic agents
Nucl. Compact
99mTc labeled 1-hydroxy ethylene-1,1-disodium phosphonate
J. Nucl. Med.
Polymer embedded nanocrystalline titania sorbent for 99Mo-99mTc generator
J. Nanosci. Nanotechnol.
A novel 188W/188Re electrochemical generator with potential for medical applications
Radiochim. Acta
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