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Nanostructured porous silicon in preclinical imaging: Moving from bench to bedside

Published online by Cambridge University Press:  29 August 2012

Hélder A. Santos*
Affiliation:
Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland
Luis M. Bimbo
Affiliation:
Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland
Barbara Herranz
Affiliation:
Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland
Mohammad-Ali Shahbazi
Affiliation:
Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland; and Department of Pharmaceutics, Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
Jouni Hirvonen
Affiliation:
Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland
Jarno Salonen
Affiliation:
Department of Physics, Laboratory of Industrial Physics, University of Turku, Turku FI-20014, Finland
*
a)Address all correspondence to this author. e-mail: helder.santos@helsinki.fi
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Abstract

Advances in nanotechnology have prompted rapid progress and versatile imaging modalities for diagnostics and treatment of diseases. Molecular imaging is a powerful technique for quantifying physiological changes in vivo using noninvasive imaging probes. These probes are used to image specific cells and tissues within a whole organism. Currently, imaging is an essential part of clinical protocols providing morphological, structural, metabolic and functional information. Using theranostic micro- or nanoparticles, which combine both therapeutic and diagnostic capabilities in one single entity, holds a true promise to propel the biomedical field toward personalized medicine. With this approach, biological processes can be directly and simultaneously monitored with the treatment of the diseases. This mini-review highlights the recent innovative diagnostic imaging aspects of porous silicon (PSi) materials and emphasizes their potential as theranostic platforms and tools for the clinic. Multiple biomedical imaging applications of the PSi materials are also outlined.

Type
Review Article
Copyright
Copyright © Materials Research Society 2012

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References

REFERENCES

Santos, H.A., Bimbo, L.M., Lehto, V.P., Airaksinen, A.J., Salonen, J., and Hirvonen, J.: Multifunctional porous silicon for therapeutic drug delivery and imaging. Curr. Drug Discov. Technol. 8, 228 (2011).CrossRefGoogle ScholarPubMed
Auffan, M., Rose, J., Bottero, J.Y., Lowry, G.V., Jolivet, J.P., and Wiesner, M.R.: Towards a definition of inorganic nanoparticles from an environmental, health and safety perspective. Nat. Nanotechnol. 4, 634 (2009).CrossRefGoogle ScholarPubMed
Godin, B., Tasciotti, E., Liu, X., Serda, R.E., and Ferrari, M.: Multistage nanovectors: From concept to novel imaging contrast agents and therapeutics. Acc. Chem. Res. 44, 979 (2011).CrossRefGoogle Scholar
Fass, L.: Imaging and cancer: A review. Mol. Oncol. 2, 115 (2008).CrossRefGoogle ScholarPubMed
Cho, N-H., Cheong, T-C., Min, J.H., Wu, J.H., Lee, S.J., Kim, D., Yang, J-S., Kim, S., Kim, Y.K., and Seong, S-Y.: A multifunctional core-shell nanoparticle for dendritic cell-based cancer immunotherapy. Nat. Nanotechnol. 6, 675 (2011).CrossRefGoogle ScholarPubMed
Das, M., Mishra, D., Dhak, P., Gupta, S., Maiti, T.K., Basak, A., and Pramanik, P.: Biofunctionalized, phosphonate-grafted, ultrasmall iron oxide nanoparticles for combined targeted cancer therapy and multimodal imaging. Small 5, 2883 (2009).CrossRefGoogle ScholarPubMed
Farokhzad, O.C. and Langer, R.: Impact of nanotechnology on drug delivery. ACS Nano 3, 16 (2009).CrossRefGoogle ScholarPubMed
Ferrari, M.: Cancer nanotechnology: Opportunities and challenges. Nat. Rev. Cancer 5, 161 (2005).CrossRefGoogle ScholarPubMed
Kelkar, S.S. and Reineke, T.M.: Theranostics: Combining imaging and therapy. Bioconjugate Chem. 22, 1879 (2011).CrossRefGoogle ScholarPubMed
Sumer, B. and Gao, J.: Theranostic nanomedicine for cancer. Nanomedicine 3, 137 (2008).CrossRefGoogle ScholarPubMed
Jaffer, F.A. and Weissleder, R.: Molecular imaging in the clinical arena. JAMA 293, 855 (2005).CrossRefGoogle ScholarPubMed
Minchin, R.F. and Martin, D.J.: Minireview: Nanoparticles for molecular imaging—an overview. Endocrinology 151, 474 (2010).CrossRefGoogle Scholar
Weissleder, R.: Molecular imaging in cancer. Science 312, 1168 (2006).CrossRefGoogle ScholarPubMed
Massoud, T.F. and Gambhir, S.S.: Molecular imaging in living subjects: Seeing fundamental biological processes in a new light. Genes Dev. 17, 545 (2003).CrossRefGoogle Scholar
Iagaru, A., Masamed, R., Keesara, S., and Conti, P.: Breast MRI and 18F FDG PET/CT in the management of breast cancer. Ann. Nucl. Med. 21, 33 (2007).CrossRefGoogle ScholarPubMed
Kjær, A.: Molecular imaging of cancer using PET and SPECT, in New Trends in Cancer for the 21st Century, Vol. 587, edited by Llombart-Bosch, A., Felipo, V., and Lopes-Guerrero, J.A. (Springer, New York, NY, 2006); p. 277.CrossRefGoogle Scholar
Ray, P., Wu, A.M., and Gambhir, S.S.: Optical bioluminescence and positron emission tomography imaging of a novel fusion reporter gene in tumor xenografts of living mice. Cancer Res. 63, 1160 (2003).Google ScholarPubMed
Atri, M.: New technologies and directed agents for applications of cancer imaging. J. Clin. Oncol. 24, 3299 (2006).CrossRefGoogle ScholarPubMed
Luo, S., Zhang, E., Su, Y., Cheng, T., and Shi, C.: A review of NIR dyes in cancer targeting and imaging. Biomaterials 32, 7127 (2011).CrossRefGoogle ScholarPubMed
Campbell, J.L., Arora, J., Cowell, S.F., Garg, A., Eu, P., Bhargava, S.K., and Bansal, V.: Quasicubic magnetite/silica core-shell nanoparticles as enhanced MRI contrast agents for cancer imaging. PLoS One 6, e21857 (2011).CrossRefGoogle ScholarPubMed
Wan, X., Wang, D., and Liu, S.: Fluorescent pH-sensing organic/inorganic hybrid mesoporous silica nanoparticles with tunable redox-responsive release capability. Langmuir 26, 15574 (2010).CrossRefGoogle ScholarPubMed
Gao, X., Cui, Y., Levenson, R.M., Chung, L.W.K., and Nie, S.: In vivo cancer targeting and imaging with semiconductor quantum dots. Nat. Biotechnol. 22, 969 (2004).CrossRefGoogle ScholarPubMed
Michalet, X., Pinaud, F.F., Bentolila, L.A., Tsay, J.M., Doose, S., Li, J.J., Sundaresan, G., Wu, A.M., Gambhir, S.S., and Weiss, S.: Quantum dots for live cells, in vivo imaging, and diagnostics. Science 307, 538 (2005).CrossRefGoogle ScholarPubMed
Huang, C.C., Khu, N.H., and Yeh, C.S.: The characteristics of sub 10 nm manganese oxide T1 contrast agents of different nanostructured morphologies. Biomaterials 31, 4073 (2010).CrossRefGoogle ScholarPubMed
Wu, E.C., Andrew, J.S., Cheng, L., Freeman, W.R., Pearson, L., and Sailor, M.J.: Real-time monitoring of sustained drug release using the optical properties of porous silicon photonic crystal particles. Biomaterials 32, 1957 (2011).CrossRefGoogle ScholarPubMed
Salonen, J., Kaukonen, A.M., Hirvonen, J., and Lehto, V.P.: Mesoporous silicon in drug delivery applications. J. Pharm. Sci. 97, 632 (2008).CrossRefGoogle ScholarPubMed
Anglin, E.J., Cheng, L., Freeman, W.R., and Sailor, M.J.: Porous silicon in drug delivery devices and materials. Adv. Drug Delivery Rev. 60, 1266 (2008).CrossRefGoogle ScholarPubMed
Bimbo, L.M., Makila, E., Laaksonen, T., Lehto, V.P., Salonen, J., Hirvonen, J., and Santos, H.A.: Drug permeation across intestinal epithelial cells using porous silicon nanoparticles. Biomaterials 32, 2625 (2011).CrossRefGoogle ScholarPubMed
Bimbo, L.M., Makila, E., Raula, J., Laaksonen, T., Laaksonen, P., Strommer, K., Kauppinen, E.I., Salonen, J., Linder, M.B., Hirvonen, J., and Santos, H.A.: Functional hydrophobin-coating of thermally hydrocarbonized porous silicon microparticles. Biomaterials 32, 9089 (2011).CrossRefGoogle ScholarPubMed
Kinnari, P., Makila, E., Heikkila, T., Salonen, J., Hirvonen, J., and Santos, H.A.: Comparison of mesoporous silicon and nonordered mesoporous silica materials as drug carriers for itraconazole. Int. J. Pharm. 414, 148 (2011).CrossRefGoogle ScholarPubMed
Laaksonen, T., Santos, H., Vihola, H., Salonen, J., Riikonen, J., Heikkila, T., Peltonen, L., Kumar, N., Murzin, D.Y., Lehto, V.P., and Hirvonen, J.: Failure of MTT as a toxicity testing agent for mesoporous silicon microparticles. Chem. Res. Toxicol. 20, 1913 (2007).CrossRefGoogle ScholarPubMed
Vale, N., Mäkilä, E., Salonen, J., Gomes, P., Hirvonen, J., and Santos, H.A.: New times, new trends for ethionamide: In vitro evaluation of drug-loaded thermally carbonized porous silicon microparticles. Eur. J. Pharm. Biopharm. 81, 314 (2012).CrossRefGoogle ScholarPubMed
Tahvanainen, M., Rotko, T., Mäkilä, E., Santos, H.A., Neves, D., Laaksonen, T., Kallonen, A., Hämäläinen, K., Peura, M., Serimaa, R., Salonen, J., Hirvonen, J., and Peltonen, L.: Tablet preformulations of indomethacin-loaded mesoporous silicon microparticles. Int. J. Pharm. 422, 125 (2012).CrossRefGoogle ScholarPubMed
McInnes, S.J.P. and Voelcker, N.H.: Silicon–polymer hybrid materials for drug delivery. Future Med. Chem. 1, 1051 (2009).CrossRefGoogle ScholarPubMed
Santos, H.A., Salonen, J., Bimbo, L.M., Lehto, V.P., Peltonen, L., and Hirvonen, J.: Mesoporous materials as controlled drug delivery formulations. J. Drug Delivery Sci. Technol. 21, 139 (2011).CrossRefGoogle Scholar
Wu, E.C., Park, J.H., Park, J., Segal, E., Cunin, F., and Sailor, M.J.: Oxidation-triggered release of fluorescent molecules or drugs from mesoporous Si microparticles. ACS Nano 2, 2401 (2008).CrossRefGoogle ScholarPubMed
Tasciotti, E., Godin, B., Martinez, J.O., Chiappini, C., Bhavane, R., Liu, X., and Ferrari, M.: Near-infrared imaging method for the in vivo assessment of the biodistribution of nanoporous silicon particles. Mol. Imaging 10, 56 (2011).CrossRefGoogle ScholarPubMed
Tasciotti, E., Liu, X., Bhavane, R., Plant, K., Leonard, A.D., Price, B.K., Cheng, M.M., Decuzzi, P., Tour, J.M., Robertson, F., and Ferrari, M.: Mesoporous silicon particles as a multistage delivery system for imaging and therapeutic applications. Nat. Nanotechnol. 3, 151 (2008).CrossRefGoogle ScholarPubMed
Park, J.H., Gu, L., von Maltzahn, G., Ruoslahti, E., Bhatia, S.N., and Sailor, M.J.: Biodegradable luminescent porous silicon nanoparticles for in vivo applications. Nat. Mater. 8, 331 (2009).CrossRefGoogle ScholarPubMed
Cheng, L., Anglin, E., Cunin, F., Kim, D., Sailor, M.J., Falkenstein, I., Tammewar, A., and Freeman, W.R.: Intravitreal properties of porous silicon photonic crystals: A potential self-reporting intraocular drug-delivery vehicle. Br. J. Ophthalmol. 92, 705 (2008).CrossRefGoogle ScholarPubMed
Sarparanta, M.P., Bimbo, L.M., Makila, E.M., Salonen, J.J., Laaksonen, P.H., Helariutta, A.M., Linder, M.B., Hirvonen, J.T., Laaksonen, T.J., Santos, H.A., and Airaksinen, A.J.: The mucoadhesive and gastroretentive properties of hydrophobin-coated porous silicon nanoparticle oral drug delivery systems. Biomaterials 33, 3353 (2012).CrossRefGoogle ScholarPubMed
Bimbo, L.M., Sarparanta, M., Santos, H.A., Airaksinen, A.J., Makila, E., Laaksonen, T., Peltonen, L., Lehto, V.P., Hirvonen, J., and Salonen, J.: Biocompatibility of thermally hydrocarbonized porous silicon nanoparticles and their biodistribution in rats. ACS Nano 4, 3023 (2010).CrossRefGoogle ScholarPubMed
Sarparanta, M., Bimbo, L.M., Rytkonen, J., Makila, E., Laaksonen, T.J., Laaksonen, P., Nyman, M., Salonen, J., Linder, M.B., Hirvonen, J., Santos, H.A., and Airaksinen, A.J.: Intravenous delivery of hydrophobin-functionalized porous silicon nanoparticles: stability, plasma protein adsorption and biodistribution. Mol. Pharmaceutics 9, 654 (2012).CrossRefGoogle ScholarPubMed
Sarparanta, M., Makila, E., Heikkila, T., Salonen, J., Kukk, E., Lehto, V.P., Santos, H.A., Hirvonen, J., and Airaksinen, A.J.: 18F-labeled modified porous silicon particles for investigation of drug delivery carrier distribution in vivo with positron emission tomography. Mol. Pharmaceutics 8, 1799 (2011).CrossRefGoogle ScholarPubMed
Low, S.P., Williams, K.A., Canham, L.T., and Voelcker, N.H.: Evaluation of mammalian cell adhesion on surface-modified porous silicon. Biomaterials 27, 4538 (2006).CrossRefGoogle ScholarPubMed
Santos, H.A., Riikonen, J., Salonen, J., Makila, E., Heikkila, T., Laaksonen, T., Peltonen, L., Lehto, V.P., and Hirvonen, J.: In vitro cytotoxicity of porous silicon microparticles: Effect of the particle concentration, surface chemistry and size. Acta Biomater. 6, 2721 (2010).CrossRefGoogle ScholarPubMed
Bimbo, L.M., Sarparanta, M., Makila, E., Laaksonen, T., Laaksonen, P., Salonen, J., Linder, M.B., Hirvonen, J., Airaksinen, A.J., and Santos, H.A.: Cellular interactions of surface-modified nanoporous silicon particles. Nanoscale 4, 3184 (2012).CrossRefGoogle ScholarPubMed
Low, S.P., Voelcker, N.H., Canham, L.T., and Williams, K.A.: The biocompatibility of porous silicon in tissues of the eye. Biomaterials 30, 2873 (2009).CrossRefGoogle ScholarPubMed
McInnes, S.J., Irani, Y., Williams, K.A., and Voelcker, N.H.: Controlled drug delivery from composites of nanostructured porous silicon and poly(L-lactide). Nanomedicine 6, 6 (2012).Google Scholar
Canham, L.T., Kluczewska, A.A., Barley, J.P., and Varajao, R.F.D.C.: Imaging agents comprising silicon. WO/2007/034196, (March 29, 2007).Google Scholar
Bisi, O., Ossicini, S., and Pavesi, L.: Porous silicon: A quantum sponge structure for silicon based optoelectronics. Surf. Sci. Rep. 38, 1 (2000).CrossRefGoogle Scholar
Cunin, F., Schmedake, T.A., Link, J.R., Li, Y.Y., Koh, J., Bhatia, S.N., and Sailor, M.J.: Biomolecular screening with encoded porous silicon photonic crystals. Nat. Mater. 1, 39 (2002).CrossRefGoogle ScholarPubMed
D’Hallewin, M-A., El Khatib, S., Leroux, A., Bezdetnaya, L., and Guillemin, F.: Endoscopic confocal fluorescence microscopy of normal and tumor-bearing rat bladder. J. Urol. 174, 736 (2005).CrossRefGoogle ScholarPubMed
He, W., Wang, H., Hartmann, L.C., Cheng, J-X., and Low, P.S.: In vivo quantitation of rare circulating tumor cells by multiphoton intravital flow cytometry. Proc. Natl. Acad. Sci. U.S.A. 104, 11760 (2007).CrossRefGoogle ScholarPubMed
Serda, R.E., Godin, B., Blanco, E., Chiappini, C., and Ferrari, M.: Multistage delivery nanoparticle systems for therapeutic applications. Biochim. Biophys. Acta 1810, 317 (2011).CrossRefGoogle ScholarPubMed
Li, Y.Y., Cunin, F., Link, J.R., Gao, T., Betts, R.E., Reiver, S.H., Chin, V., Bhatia, S.N., and Sailor, M.J.: Polymer replicas of photonic porous silicon for sensing and drug delivery applications. Science 299, 2045 (2003).CrossRefGoogle ScholarPubMed
Choy, G., Choyke, P., and Libutti, S.K.: Current advances in molecular imaging: Noninvasive in vivo bioluminescent and fluorescent optical imaging in cancer research. Mol. Imaging 2, 303 (2003).CrossRefGoogle Scholar
Canham, L.T.: Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers. Appl. Phys. Lett. 57, 1046 (1990).CrossRefGoogle Scholar
Jurbergs, D., Rogojina, E., Mangolini, L., and Kortshagen, U.: Silicon nanocrystals with ensemble quantum yields exceeding 60%. Appl. Phys. Lett. 88, 233116 (2006).CrossRefGoogle Scholar
Hong, C., Lee, J., Son, M., Hong, S.S., and Lee, C.: In vivo cancer cell destruction using porous silicon nanoparticles. Anticancer Drugs 22, 971 (2011).CrossRefGoogle ScholarPubMed
Tilley, R.D. and Yamamoto, K.: The microemulsion synthesis of hydrophobic and hydrophilic silicon nanocrystals. Adv. Mater. 18, 2053 (2006).CrossRefGoogle Scholar
Weissleder, R.: A clearer vision for in vivo imaging. Nat. Biotechnol. 19, 316 (2001).CrossRefGoogle ScholarPubMed
Aime, S., Castelli, D.D., Crich, S.G., Gianolio, E., and Terreno, E.: Pushing the sensitivity envelope of lanthanide-based magnetic resonance imaging (MRI) contrast agents for molecular imaging applications. Acc. Chem. Res. 42, 822 (2009).CrossRefGoogle ScholarPubMed
Chen, T., Shukoor, M.I., Wang, R., Zhao, Z., Yuan, Q., Bamrungsap, S., Xiong, X., and Tan, W.: Smart multifunctional nanostructure for targeted cancer chemotherapy and magnetic resonance imaging. ACS Nano 5, 7866 (2011).CrossRefGoogle ScholarPubMed
Jain, R., Dandekar, P., and Patravale, V.: Diagnostic nanocarriers for sentinel lymph node imaging. J. Controlled Release 138, 90 (2009).CrossRefGoogle ScholarPubMed
Zhou, Z., Li, D., Yang, H., Zhu, Y., and Yang, S.: Synthesis of d-f coordination polymer nanoparticles and their application in phosphorescence and magnetic resonance imaging. Dalton Trans. 40, 11941 (2011).CrossRefGoogle ScholarPubMed
Terreno, E., Castelli, D.D., Viale, A., and Aime, S.: Challenges for molecular magnetic resonance imaging. Chem. Rev. 110, 3019 (2010).CrossRefGoogle ScholarPubMed
Werner, E.J., Datta, A., Jocher, C.J., and Raymond, K.N.: High-relaxivity MRI contrast agents: Where coordination chemistry meets medical imaging. Angew. Chem. Int. Ed. 47, 8568 (2008).CrossRefGoogle ScholarPubMed
Jun, Y.W., Lee, J.H., and Cheon, J.: Chemical design of nanoparticle probes for high-performance magnetic resonance imaging. Angew. Chem. Int. Ed. 47, 5122 (2008).CrossRefGoogle ScholarPubMed
Viswanathan, S., Kovacs, Z., Green, K.N., Ratnakar, S.J., and Sherry, A.D.: Alternatives to gadolinium-based metal chelates for magnetic resonance imaging. Chem. Rev. 110, 2960 (2010).CrossRefGoogle ScholarPubMed
Yu, M.K., Jeong, Y.Y., Park, J., Park, S., Kim, J.W., Min, J.J., Kim, K., and Jon, S.: Drug-loaded superparamagnetic iron oxide nanoparticles for combined cancer imaging and therapy in vivo. Angew. Chem. Int. Ed. 47, 5362 (2008).CrossRefGoogle ScholarPubMed
Berret, J.F., Schonbeck, N., Gazeau, F., El Kharrat, D., Sandre, O., Vacher, A., and Airiau, M.: Controlled clustering of superparamagnetic nanoparticles using block copolymers: Design of new contrast agents for magnetic resonance imaging. J. Am. Chem. Soc. 128, 1755 (2006).CrossRefGoogle ScholarPubMed
Ntziachristos, V., Bremer, C., and Weissleder, R.: Fluorescence imaging with near-infrared light: New technological advances that enable in vivo molecular imaging. Eur. J. Radiol. 13, 195 (2003).CrossRefGoogle ScholarPubMed
Ananta, J.S., Godin, B., Sethi, R., Moriggi, L., Liu, X., Serda, R.E., Krishnamurthy, R., Muthupillai, R., Bolskar, R.D., Helm, L., Ferrari, M., Wilson, L.J., and Decuzzi, P.: Geometrical confinement of gadolinium-based contrast agents in nanoporous particles enhances T1 contrast. Nat. Nanotechnol. 5, 815 (2010).CrossRefGoogle ScholarPubMed
Serda, R.E., Mack, A., Pulikkathara, M., Zaske, A.M., Chiappini, C., Fakhoury, J.R., Webb, D., Godin, B., Conyers, J.L., Liu, X.W., Bankson, J.A., and Ferrari, M.: Cellular association and assembly of a multistage delivery system. Small 6, 1329 (2010).CrossRefGoogle ScholarPubMed
Stark, D.D., Weissleder, R., Elizondo, G., Hahn, P.F., Saini, S., Todd, L.E., Wittenberg, J., and Ferrucci, J.T.: Superparamagnetic iron oxide: Clinical application as a contrast agent for MR imaging of the liver. Radiology 168, 297 (1988).CrossRefGoogle ScholarPubMed
Kinsella, J.M., Ananda, S., Andrew, J.S., Grondek, J.F., Chien, M-P., Scadeng, M., Gianneschi, N.C., Ruoslahti, E., and Sailor, M.J.: Enhanced magnetic resonance contrast of Fe3O4 nanoparticles trapped in a porous silicon nanoparticle host. Adv. Mater. 23, H248 (2011).CrossRefGoogle Scholar
Hamoudeh, M., Kamleh, M.A., Diab, R., and Fessi, H.: Radionuclides delivery systems for nuclear imaging and radiotherapy of cancer. Adv. Drug Delivery Rev. 60, 1329 (2008).CrossRefGoogle ScholarPubMed
Debbage, P. and Jaschke, W.: Molecular imaging with nanoparticles: Giant roles for dwarf actors. Histochem. Cell. Biol. 130, 845 (2008).CrossRefGoogle ScholarPubMed
Li, Z. and Conti, P.S.: Radiopharmaceutical chemistry for positron emission tomography. Adv. Drug Delivery Rev. 62, 1031 (2010).CrossRefGoogle ScholarPubMed
Vallabhajosula, S., Solnes, L., and Vallabhajosula, B.: A broad overview of positron emission tomography radiopharmaceuticals and clinical applications: What is new? Semin. Nucl. Med. 41, 246 (2011).CrossRefGoogle Scholar
Tu, C., Ma, X., House, A., Kauzlarich, S.M., and Louie, A.Y.: PET imaging and biodistribution of silicon quantum dots in mice. ACS Med. Chem. Lett. 2, 285 (2011).CrossRefGoogle ScholarPubMed
Pysz, M.A., Gambhir, S.S., and Willmann, J.K.: Molecular imaging: Current status and emerging strategies. Clin. Radiol. 65, 500 (2010).CrossRefGoogle ScholarPubMed
Lecchi, M., Ottobrini, L., Martelli, C., Del Sole, A., and Lucignani, G.: Instrumentation and probes for molecular and cellular imaging. Q. J. Nucl. Med. Mol. Imaging 51, 111 (2007).Google ScholarPubMed
Committee on State of the Science of Nuclear Medicine, National Research Council, in Advancing Nuclear Medicine through Innovation (National Academies Press, Washington, DC, 2007).Google Scholar
86.Goh, A.S-W., Chung, A.Y-F., Lo, R.H-G., Lau, T-N., Yu, S.W-K., Chng, M., Satchithanantham, S., Loong, S.L-E., Ng, D.C-E., Lim, B-C., Connor, S., and Chow, P.K-H.: A novel approach to brachytherapy in hepatocellular carcinoma using a phosphorous32 (32P) brachytherapy delivery device—a first-in-man study. Int. J. Radiat. Oncol. Biol. Phys. 67, 786 (2007).CrossRefGoogle ScholarPubMed
87.www.psivida.com (accessed 10 June 2012).Google Scholar