1
|
225Ac-rHDL Nanoparticles: A Potential Agent for Targeted Alpha-Particle Therapy of Tumors Overexpressing SR-BI Proteins. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27072156. [PMID: 35408554 PMCID: PMC9000893 DOI: 10.3390/molecules27072156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/18/2022] [Accepted: 03/23/2022] [Indexed: 11/25/2022]
Abstract
Actinium-225 and other alpha-particle-emitting radionuclides have shown high potential for cancer treatment. Reconstituted high-density lipoproteins (rHDL) specifically recognize the scavenger receptor B type I (SR-BI) overexpressed in several types of cancer cells. Furthermore, after rHDL-SR-BI recognition, the rHDL content is injected into the cell cytoplasm. This research aimed to prepare a targeted 225Ac-delivering nanosystem by encapsulating the radionuclide into rHDL nanoparticles. The synthesis of rHDL was performed in two steps using the microfluidic synthesis method for the subsequent encapsulation of 225Ac, previously complexed to a lipophilic molecule (225Ac-DOTA-benzene-p-SCN, CLog P = 3.42). The nanosystem (13 nm particle size) showed a radiochemical purity higher than 99% and stability in human serum. In vitro studies in HEP-G2 and PC-3 cancer cells (SR-BI positive) demonstrated that 225Ac was successfully internalized into the cytoplasm of cells, delivering high radiation doses to cell nuclei (107 Gy to PC-3 and 161 Gy to HEP-G2 nuclei at 24 h), resulting in a significant decrease in cell viability down to 3.22 ± 0.72% for the PC-3 and to 1.79 ± 0.23% for HEP-G2 at 192 h after 225Ac-rHDL treatment. After intratumoral 225Ac-rHDL administration in mice bearing HEP-G2 tumors, the biokinetic profile showed significant retention of radioactivity in the tumor masses (90.16 ± 2.52% of the injected activity), which generated ablative radiation doses (649 Gy/MBq). The results demonstrated adequate properties of rHDL as a stable carrier for selective deposition of 225Ac within cancer cells overexpressing SR-BI. The results obtained in this research justify further preclinical studies, designed to evaluate the therapeutic efficacy of the 225Ac-rHDL system for targeted alpha-particle therapy of tumors that overexpress the SR-BI receptor.
Collapse
|
2
|
Peptide Receptor Radionuclide Therapy (PRRT) with 177Lu-DOTATATE; Differences in Tumor Dosimetry, Vascularity and Lesion Metrics in Pancreatic and Small Intestinal Neuroendocrine Neoplasms. Cancers (Basel) 2021; 13:cancers13050962. [PMID: 33668887 PMCID: PMC7956792 DOI: 10.3390/cancers13050962] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/12/2021] [Accepted: 02/19/2021] [Indexed: 12/20/2022] Open
Abstract
Simple Summary Patients suffering from disseminated, progressive, neuroendocrine neoplasms with a sufficient amount of somatostatin receptors and good kidney function can be treated with radioactive hormone-like molecules to prolong their life. In this study, the radioactivity in one tumor per patient at each treatment cycle was calculated and compared between 23 patients with pancreatic and 25 patients with small intestinal neuroendocrine neoplasia. Both types of tumors absorb a larger amount of radioactivity during early cycles that subsequently decline in the later cycles. This finding was more pronounced in the pancreatic tumors, which also expressed higher blood perfusion in the early cycles, known to facilitate the effect of radiation. This could be part of the reason why the pancreatic tumors shrunk more rapidly than the small intestinal ones. Our results also imply that increased administered activity in the early therapy cycles may be beneficial, at least in pancreatic neuroendocrine tumor patients. Abstract Dosimetry during peptide receptor radionuclide therapy (PRRT) has mainly focused on normal organs and less on the tumors. The absorbed dose in one target tumor per patient and several response related factors were assessed in 23 pancreatic neuroendocrine neoplasms (P-NENs) and 25 small-intestinal NEN (SI-NENs) during PRRT with 177Lu-DOTATATE. The total administered activity per patient was (mean ± standard error of mean (SEM) 31.8 ± 1.9 GBq for P-NENs and 36 ± 1.94 GBq for SI-NENs. The absorbed tumor dose was 143.5 ± 2 Gy in P-NENs, 168.2 ± 2 Gy in SI-NENs. For both NEN types, a dose–response relationship was found between the absorbed dose and tumor shrinkage, which was more pronounced in P-NENs. A significant drop in the absorbed dose per cycle was shown during the course of PRRT. Tumor vascularization was higher in P-NENs than in SI-NENs at baseline but equal post-PRRT. The time to progression (RECIST 1.1) was similar for patients with P-NEN (mean ± SEM 30 ± 1 months) and SI-NEN (33 ± 1 months). In conclusion, a dose response relationship was established for both P-NENs and SI-NENs and a significant drop in the absorbed dose per cycle was shown during the course of PRRT, which warrants further investigation to understand the factors impacting PRRT to improve personalized treatment protocol design.
Collapse
|
3
|
Siragusa M, Baiocco G, Fredericia PM, Friedland W, Groesser T, Ottolenghi A, Jensen M. The COOLER Code: A Novel Analytical Approach to Calculate Subcellular Energy Deposition by Internal Electron Emitters. Radiat Res 2017. [DOI: 10.1667/rr14683.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Mattia Siragusa
- Hevesy Laboratory, Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark
| | | | - Pil M. Fredericia
- Hevesy Laboratory, Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark
| | - Werner Friedland
- Institute of Radiation Protection, Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Torsten Groesser
- Hevesy Laboratory, Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark
| | | | - Mikael Jensen
- Hevesy Laboratory, Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark
| |
Collapse
|
4
|
Sung W, Jung S, Ye SJ. Evaluation of the microscopic dose enhancement for nanoparticle-enhanced Auger therapy. Phys Med Biol 2016; 61:7522-7535. [PMID: 27716643 DOI: 10.1088/0031-9155/61/21/7522] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this study is to investigate the dosimetric characteristics of nanoparticle-enhanced Auger therapy. Monte Carlo (MC) simulations were performed to assess electron energy spectra and dose enhancement distributions around a nanoparticle. In the simulations, two types of nanoparticle structures were considered: nanoshell and nanosphere, both of which were assumed to be made of one of five elements (Fe, Ag, Gd, Au, and Pt) in various sizes (2-100 nm). Auger-electron emitting radionuclides (I-125, In-111, and Tc-99m) were simulated within a nanoshell or on the surface of a nanosphere. For the most promising combination of Au and I-125, the maximum dose enhancement was up to 1.3 and 3.6 for the nanoshell and the nanosphere, respectively. The dose enhancement regions were restricted within 20-100 nm and 0-30 nm distances from the surface of Au nanoshell and nanosphere, respectively. The dose enhancement distributions varied with sizes of nanoparticles, nano-elements, and radionuclides and thus should be carefully taken into account for biological modeling. If the nanoparticles are accumulated in close proximity to the biological target, this new type of treatment can deliver an enhanced microscopic dose to the target (e.g. DNA). Therefore, we conclude that Auger therapy combined with nanoparticles could have the potential to provide a better therapeutic effect than conventional Auger therapy alone.
Collapse
Affiliation(s)
- Wonmo Sung
- Department of Transdisciplinary Studies, Program in Biomedical Radiation Sciences, Seoul National University Graduate School of Convergence Science and Technology, Seoul, Korea. Biomedical Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | | | | |
Collapse
|
5
|
Göstring L, Lindegren S, Gedda L. 17AAG-induced internalisation of HER2-specific Affibody molecules. Oncol Lett 2016; 12:2574-2580. [PMID: 27698830 PMCID: PMC5038849 DOI: 10.3892/ol.2016.4990] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 06/16/2016] [Indexed: 02/03/2023] Open
Abstract
The geldanamycin derivative 17-allylamino-17-demethoxygeldanamycin (17-AAG) is known to induce internalisation and degradation of the otherwise internalisation-resistant human epidermal growth factor receptor 2 (HER2) receptor. In the present study, 17-AAG was used to increase internalisation of the HER2-specific Affibody molecule ABY-025. The cellular redistribution of halogen-labelled 211At-ABY-025 and radiometal-labelled 111In-ABY-025 following treatment with 17-AAG was studied. 17-AAG treatment of SKOV-3 human ovarian carcinoma and SKBR-3 human breast carcinoma cells to some extent shifted the localisation of 111In-ABY-025 from the cell surface to intracellular compartments in the two cell lines. ABY-025 labelled with the high-linear energy transfer α emitter 211At was also internalised to a higher degree; however, due to its physiological properties, this nuclide was excreted faster. The results indicate that 17-AAG may be used to facilitate cell-specific intracellular localisation of a suitable cytotoxic or radioactive agent coupled to ABY-025 in HER2-overexpressing cells.
Collapse
Affiliation(s)
- Lovisa Göstring
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185 Uppsala, Sweden
| | - Sture Lindegren
- Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg, SE-41345 Gothenburg, Sweden
| | - Lars Gedda
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-75185 Uppsala, Sweden; Swedish Radiation Safety Authority, SE-17116, Stockholm, Sweden
| |
Collapse
|
6
|
Hanaoka H, Nagaya T, Sato K, Nakamura Y, Watanabe R, Harada T, Gao W, Feng M, Phung Y, Kim I, Paik CH, Choyke PL, Ho M, Kobayashi H. Glypican-3 targeted human heavy chain antibody as a drug carrier for hepatocellular carcinoma therapy. Mol Pharm 2015; 12:2151-7. [PMID: 25955255 PMCID: PMC7720675 DOI: 10.1021/acs.molpharmaceut.5b00132] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Glypican-3 (GPC3) represents an attractive target for hepatocellular carcinoma (HCC) therapy because it is highly expressed in HCC but not in adult normal tissue. Recently, high affinity anti-GPC3 antibodies have been developed; however, full antibodies may not penetrate evenly into tumor parenchyma, reducing their effectiveness. In this study, we compared a whole IgG antibody, anti-GPC3 YP7, with an anti-GPC3 human heavy chain antibody, HN3, with regard to their relative therapeutic effects. Both YP7 and HN3 bound to GPC3-positive A431/G1 cells and were internalized by the cells by in vitro evaluation with (125)I- and (111)In-radiolabeling antibodies. In vivo biodistribution and tumor accumulation was performed with (111)In-labeled antibodies, and intratumoral microdistribution was evaluated using fluorescently labeled antibodies (IR700). HN3 showed similar high tumor accumulation but superior homogeneity within the tumor compared with YP7. Using the same IR700 conjugated antibodies photoimmunotherapy (PIT) was performed in vitro and in a tumor-bearing mouse model in vivo. PIT with IR700-HN3 and IR700-YP7 demonstrated that comparable results could be achieved despite of low reaccumulation 24 h after the first NIR light exposure. These results indicated that a heavy-chain antibody, HN3, showed more favorable characteristics than YP7, a conventional IgG, as a therapeutic antibody platform for designing molecularly targeted agents against HCC.
Collapse
Affiliation(s)
- Hirofumi Hanaoka
- †Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Tadanobu Nagaya
- †Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Kazuhide Sato
- †Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Yuko Nakamura
- †Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Rira Watanabe
- †Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Toshiko Harada
- †Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Wei Gao
- ‡Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Mingqian Feng
- ‡Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Yen Phung
- ‡Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Insook Kim
- §Applied/Developmental Research Directorate, Leidos Biomedical Research Inc., Frederick National Laboratory, Frederick, Maryland 21702, United States
| | - Chang H Paik
- ∥Nuclear Medicine Department, Warren Grant Magnuson Clinical Center, Radiology and Imaging Science, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Peter L Choyke
- †Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Mitchell Ho
- ‡Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Hisataka Kobayashi
- †Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| |
Collapse
|
7
|
Bhupathiraju NDK, Vicente MGH. Synthesis and cellular studies of polyamine conjugates of a mercaptomethyl-carboranylporphyrin. Bioorg Med Chem 2013; 21:485-95. [PMID: 23219853 PMCID: PMC3547609 DOI: 10.1016/j.bmc.2012.11.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/24/2012] [Accepted: 11/06/2012] [Indexed: 11/29/2022]
Abstract
Seven polyamine conjugates of a tri(p-carboranylmethylthio)tetrafluorophenylporphyrin were prepared in high yields by sequential substitution of the p-phenyl fluoride of tetrakis(pentafluorophenyl)porphyrin (TPPF), and investigated as boron delivery agents for boron neutron capture therapy (BNCT). The polyamines used were derivatives of the natural-occurring spermine with different lengths of the carbon chains, terminal primary amine groups and, in two of the conjugates, additional aminoethyl moieties. A tri(polyethylene glycol) conjugate was also synthesized for comparison purposes. The polyamine conjugates showed low dark cytotoxicity (IC(50) >400 μM) and low phototoxicity (IC(50) >40 μM at 1.5 J/cm(2)). All polyamine conjugates, with one exception, showed higher uptake into human glioma T98G cells (up to 12-fold) than the PEG conjugate, and localized preferentially in the cell ER, Golgi and the lysosomes. Our results show that spermine derivatives can serve as effective carriers of boronated porphyrins for the BNCT of tumors.
Collapse
Affiliation(s)
| | - M. Graça H. Vicente
- Louisiana State University, Department of Chemistry, Baton Rouge LA, 70803, USA
| |
Collapse
|
8
|
Zanotti-Fregonara P, Champion C, Marzola MC, Rubello D, Just PA, Moretti JL, Hindié E. Monte Carlo simulation of electron dose from (131)I-targeted tumor cells within a heterogeneous tumor. Cancer Biother Radiopharm 2011; 26:135-40. [PMID: 21355785 DOI: 10.1089/cbr.2010.0831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND AND AIM In internal radiotherapy, the variable distribution of target receptors within the tumoral tissue, and the variable ranges of electrons may be responsible for a heterogeneous dose distribution at the cellular level. The aim of the present study was to use Monte Carlo simulations to assess (131)I electron dose in a model of heterogeneous tumor containing multiple clusters of cancer cells, targeted by (131)I-labeled molecules. METHODS The model consisted of 150-μm-diameter spherical tumor cell clusters, in which (131)I was homogeneously distributed. Clusters were placed 24 μm apart, separated by septa of nonradioactive connective tissue. The electron dose distribution to tumor cells in a single cluster was first assessed. Then was assessed the dose increase to these targets after adding multiple layers of neighboring clusters (total number of clusters = 15,624). RESULTS Dose distribution within a single isolated cluster follows a decreasing gradient, the dose for the outermost cell layer being about half that at the center. When radioactive neighbors were added, the dose to the central cluster increased. The most important contribution was given by the nearest neighbors, whereas the contribution from neighbors beyond a distance of 1 mm was only for 5% of the final dose. If the central cluster was unlabeled, the absorbed dose to the outermost cell layer of this cluster was reduced by 27%, and that at the center by 45%. CONCLUSIONS The electron cross-dose of (131)I falls rapidly as a function of distance and becomes negligible after just 1 mm. Small clusters of tumor cells that are not radiolabeled may receive a very small dose. Therefore, in internal radiotherapy it is important to aim at targeting tumor cells as homogeneously as possible, rather than relying on the cross-dose to achieve a therapeutic effect.
Collapse
Affiliation(s)
- Paolo Zanotti-Fregonara
- Laboratoire de Physique Moléculaire et des Collisions, Université Paul Verlaine-Metz, Institut de Physique, Metz, France
| | | | | | | | | | | | | |
Collapse
|
9
|
Bousis C, Emfietzoglou D, Hadjidoukas P, Nikjoo H. A Monte Carlo study of cellularS-factors for 1 keV to 1 MeV electrons. Phys Med Biol 2009; 54:5023-38. [DOI: 10.1088/0031-9155/54/16/012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
10
|
Emfietzoglou D, Kostarelos K, Hadjidoukas P, Bousis C, Fotopoulos A, Pathak A, Nikjoo H. Subcellular S-factors for low-energy electrons: A comparison of Monte Carlo simulations and continuous-slowing-down calculations. Int J Radiat Biol 2009; 84:1034-44. [DOI: 10.1080/09553000802460180] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
11
|
Radioimmunotherapy of solid tumors targeting a cell-surface protein, FZD10: therapeutic efficacy largely depends on radiosensitivity. Ann Nucl Med 2009; 23:479-85. [PMID: 19412654 DOI: 10.1007/s12149-009-0265-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Accepted: 03/26/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Frizzled homolog 10 (FZD10) is expressed at high levels on the cell surface of almost all synovial sarcoma tissues, but is absent in most normal organs. In a previous study, yttrium-90 ((90)Y)-labeled anti-FZD10 antibody (MAb 92-13) showed considerable therapeutic efficacy in synovial sarcoma cell-bearing mice. The purpose of the present study was to elucidate the factors associated with this therapeutic efficacy of (90)Y-MAb 92-13. METHODS FZD10 expression levels of SYO-1 (FZD10-overexpressing synovial sarcoma cell line) and DLD-1/FZD10 (FZD10-transfected DLD-1 cell) were determined by the cell binding assay, and their radiosensitivity was evaluated by incubation with (90)Y-MAb 92-13 in vitro. Biodistribution study of indium-111 ((111)In)-MAb 92-13 was performed in SYO-1 and DLD-1/FZD10 tumor-bearing mice. For therapeutic studies, SYO-1 and DLD-1/FZD10 tumor-bearing mice were treated with (90)Y-MAb 92-13 (100, 150, and 200 muCi), after which the change in tumor volume was measured. Immunohistochemical staining was performed on the excised tumor. RESULTS Expression level of FZD10 on DLD-1/FZD10 was much greater than that on SYO-1. The accumulation of (111)In-MAb 92-13 was much higher in DLD-1/FZD10 tumor-bearing mice than in SYO-1 tumor-bearing mice (49.0 +/- 4.2 and 22.0 +/- 4.5% ID/g, respectively, at 48 h after administration). In SYO-1 tumor, substantial tumor size reduction was observed in all mice treated with (90)Y-MAb 92-13 (tumor volume decreased to less than 0.1 cm(3) at 11 days after treatment) and tumor regrowth was not observed in most of them. In contrast, only slow progression was observed in DLD-1/FZD10 tumor. When incubated with (90)Y-MAb 92-13, high radioactivity was needed to damage DLD-1/FZD10. Immunohistochemical study indicated apoptosis of SYO-1 tumor. CONCLUSIONS The therapeutic efficacy of RIT seems to largely depend on the tumor radiosensitivity.
Collapse
|
12
|
Champion C, Zanotti-Fregonara P, Hindié E. Reply: 131I Radiation Dose Distribution in Metastases of Thyroid Carcinoma. J Nucl Med 2009. [DOI: 10.2967/jnumed.109.061978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
13
|
Active targeting schemes for nanoparticle systems in cancer therapeutics. Adv Drug Deliv Rev 2008; 60:1615-26. [PMID: 18840489 DOI: 10.1016/j.addr.2008.08.005] [Citation(s) in RCA: 1087] [Impact Index Per Article: 67.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 08/28/2008] [Indexed: 12/21/2022]
Abstract
The objective of this review is to outline current major cancer targets for nanoparticle systems and give insight into the direction of the field. The major targeting strategies that have been used for the delivery of therapeutic or imaging agents to cancer have been broken into three sections. These sections are angiogenesis-associated targeting, targeting to uncontrolled cell proliferation markers, and tumor cell targeting. The targeting schemes explored for many of the reported nanoparticle systems suggest the great potential of targeted delivery to revolutionize cancer treatment.
Collapse
|
14
|
Hindié E, Champion C, Zanotti-Fregonara P, Rubello D, Colas-Linhart N, Ravasi L, Moretti JL. Calculation of electron dose to target cells in a complex environment by Monte Carlo code "CELLDOSE". Eur J Nucl Med Mol Imaging 2008; 36:130-6. [PMID: 18690435 DOI: 10.1007/s00259-008-0893-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Accepted: 07/11/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND We used the Monte Carlo code "CELLDOSE" to assess the dose received by specific target cells from electron emissions in a complex environment. (131)I in a simulated thyroid was used as a model. METHODS Thyroid follicles were represented by 170 microm diameter spherical units made of a lumen of 150 microm diameter containing colloidal matter and a peripheral layer of 10 microm thick thyroid cells. Neighbouring follicles are 4 microm apart. (131)I was assumed to be homogeneously distributed in the lumen and absent in cells. We firstly assessed electron dose distribution in a single follicle. Then, we expanded the simulation by progressively adding neighbouring layers of follicles, so to reassess the electron dose to this single follicle implemented with the contribution of the added layers. RESULTS Electron dose gradient around a point source showed that the (131)I electron dose is close to zero after 2,100 microm. Therefore, we studied all contributions to the central follicle deriving from follicles within 12 orders of neighbourhood (15,624 follicles surrounding the central follicle). The dose to colloid of the single follicle was twice as high as the dose to thyroid cells. Even when all neighbours were taken into account, the dose in the central follicle remained heterogeneous. For a 1-Gy average dose to tissue, the dose to colloidal matter was 1.168 Gy, the dose to thyroid cells was 0.982 Gy, and the dose to the inter-follicular tissue was 0.895 Gy. Analysis of the different contributions to thyroid cell dose showed that 17.3% of the dose derived from the colloidal matter of their own follicle, while the remaining 82.7% was delivered by the surrounding follicles. On the basis of these data, it is shown that when different follicles contain different concentrations of (131)I, the impact in terms of cell dose heterogeneity can be important. CONCLUSION By means of (131)I in the thyroid as a theoretical model, we showed how a Monte Carlo code can be used to map electron dose deposit and build up the dose to target cells in a complex multi-source environment. This approach can be of considerable interest for comparing different radiopharmaceuticals as therapy agents in oncology.
Collapse
Affiliation(s)
- Elif Hindié
- Service de Médecine Nucléaire, Hôpital Saint-Louis, 1, avenue Claude Vellefaux, 75475, Paris Cedex 10, France.
| | | | | | | | | | | | | |
Collapse
|
15
|
Champion C, Zanotti-Fregonara P, Hindié E. CELLDOSE: A Monte Carlo Code to Assess Electron Dose Distribution—S Values for 131I in Spheres of Various Sizes. J Nucl Med 2007; 49:151-7. [DOI: 10.2967/jnumed.107.045179] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
16
|
Sibrian-Vazquez M, Hao E, Jensen TJ, Vicente MGH. Enhanced cellular uptake with a cobaltacarborane-porphyrin-HIV-1 Tat 48-60 conjugate. Bioconjug Chem 2006; 17:928-34. [PMID: 16848399 DOI: 10.1021/bc060047v] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of four porphyrin-cobaltacarborane conjugates have been synthesized, containing three or four cobaltabisdicarbollide anions linked by O(CH(2)CH(2)O)(2) groups to the porphyrin macrocycle and one of them containing a HIV-1 Tat 48-60 peptide sequence linked via a low molecular weight poly(ethylene glycol) (PEG) spacer. The cellular uptake, cytotoxicity, and preferential sites of intracellular localization of the conjugates were evaluated in human HEp2 cells. All conjugates are nontoxic in the dark at the concentrations studied. Upon exposure to low light dose (1 J cm(-)(2)) only the porphyrin-cobaltacarborane-HIV-1 Tat 48-60 conjugate showed 30% inhibition of cell proliferation at a concentration of 10 microM. The cellular uptake was dependent on the number of carborane cages and was significantly enhanced by the presence of the cell penetrating peptide sequence HIV-1 Tat 48-60. All conjugates preferentially localized in the cell lysosomes.
Collapse
|
17
|
Carlsson J, Ren ZP, Wester K, Sundberg AL, Heldin NE, Hesselager G, Persson M, Gedda L, Tolmachev V, Lundqvist H, Blomquist E, Nistér M. Planning for intracavitary anti-EGFR radionuclide therapy of gliomas. Literature review and data on EGFR expression. J Neurooncol 2006; 77:33-45. [PMID: 16200342 DOI: 10.1007/s11060-005-7410-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Targeting with radionuclide labelled substances that bind specifically to the epidermal growth factor receptor, EGFR, is considered for intracavitary therapy of EGFR-positive glioblastoma multiforme, GBM. Relevant literature is reviewed and examples of EGFR expression in GBM are given. The therapeutical efforts made so far using intracavitary anti-tenascin radionuclide therapy of GBM have given limited effects, probably due to low radiation doses to the migrating glioma cells in the brain. Low radiation doses might be due to limited penetration of the targeting agents or heterogeneity in the expression of the target structure. In this article we focus on the possibilities to target EGFR on the tumour cells instead of an extracellular matrix component. There seems to be a lack of knowledge on the degree of intratumoral variation of EGFR expression in GBM, although the expression seemed rather homogeneous over large areas in most of the examples (n=16) presented from our laboratory. The observed homogeneity was surprising considering the genomic instability and heterogeneity that generally characterises highly malignant tumours. However, overexpression of EGFR is, at least in primary GBMs, one of the steps in the development of malignancy, and tumour cells that lose or downregulate EGFR will probably be outgrown in an expanding tumour cell population. Thus, loss of EGFR expression might not be the critical factor for successful intracavitary radionuclide therapy. Instead, it is likely that the penetration properties of the targeting agents are critical, and detailed studies on this are urgent.
Collapse
Affiliation(s)
- J Carlsson
- Unit of Biomedical Radiation Sciences, Department of Oncology, Radiology and Clinical Immunology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Carlsson J, Eriksson V, Stenerlöw B, Lundqvist H. Requirements regarding dose rate and exposure time for killing of tumour cells in beta particle radionuclide therapy. Eur J Nucl Med Mol Imaging 2006; 33:1185-95. [PMID: 16718515 PMCID: PMC1998878 DOI: 10.1007/s00259-006-0109-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Accepted: 02/26/2006] [Indexed: 10/25/2022]
Abstract
PURPOSE The purpose of this study was to identify combinations of dose rate and exposure time that have the potential to provide curative treatment with targeted radionuclide therapy applying low dose rate beta irradiation. METHODS Five tumour cell lines, U-373MG and U-118MG gliomas, HT-29 colon carcinoma, A-431 cervical squamous carcinoma and SKBR-3 breast cancer, were used. An experimental model with 10(5) tumour cells in each sample was irradiated with low dose rate beta particles. The criterion for successful treatment was absence of recovery of cells during a follow-up period of 3 months. The initial dose rates were in the range 0.1-0.8 Gy/h, and the cells were continuously exposed for 1, 3 or 7 days. These combinations covered dose rates and doses achievable in targeted radionuclide therapy. RESULTS Continuous irradiation with dose rates of 0.2-0.3 and 0.4-0.6 Gy/h for 7 and 3 days, respectively, could kill all cells in each tumour cell sample. These treatments gave total radiation doses of 30-40 Gy. However, when exposed for just 24 h with about 0.8 Gy/h, only the SKBR-3 cells were successfully treated; all the other cell types recovered. There were large cell type-dependent variations in the growth delay patterns for the cultures that recovered. The U-118MG cells were most resistant and the U-373MG and SKBR-3 cells most sensitive to the treatments. The HT-29 and A-431 cells were intermediate. CONCLUSION The results serve as a guideline for the combinations of dose rate and exposure time necessary to kill tumour cells when applying low dose rate beta irradiation. The shift from recovery to "cure" fell within a narrow range of dose rate and exposure time combinations.
Collapse
Affiliation(s)
- Jörgen Carlsson
- Division of Biomedical Radiation Sciences, Department of Oncology, Radiology and Clinical Immunology, Rudbeck Laboratory, Uppsala University, SE-751 85, Uppsala, Sweden.
| | | | | | | |
Collapse
|
19
|
Sibrian-Vazquez M, Jensen TJ, Hammer RP, Vicente MGH. Peptide-mediated cell transport of water soluble porphyrin conjugates. J Med Chem 2006; 49:1364-72. [PMID: 16480271 DOI: 10.1021/jm050893b] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Five new porphyrin-peptide conjugates bearing a nuclear localizing sequence SV40 or a fusogenic peptide (HIV-1Tat 40-60 or octa-arginine) linked by low molecular weight poly(ethylene glycol) have been synthesized. In vitro studies using human HEp2 cells show that the cellular uptake of the conjugates depends significantly on the nature and sequence of amino acids in the peptide and on the nature of the substituents on the porphyrin macrocycle. The fusogenic peptide sequences HIV-1Tat 40-60 and octa-arginine were the most effective in delivering the conjugates to the cells. The subcellular distribution of the conjugates was found to be dependent on the nature of substituents on the porphyrin macrocycle. The conjugates bearing a hydrophobic porphyrin localized preferentially in the endoplasmic reticulum and were significantly more phototoxic to HEp2 cells than the carboxylic acid functionalized porphyrin conjugates, which localized mainly in the lysosomes.
Collapse
|
20
|
Almqvist Y, Orlova A, Sjöström A, Jensen HJ, Lundqvist H, Sundin A, Tolmachev V. In vitro characterization of 211 At-labeled antibody A33--a potential therapeutic agent against metastatic colorectal carcinoma. Cancer Biother Radiopharm 2006; 20:514-23. [PMID: 16248767 DOI: 10.1089/cbr.2005.20.514] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The humanized antibody A33 binds to the A33 antigen, expressed in 95% of primary and metastatic colorectal carcinomas. The restricted pattern of expression in normal tissue makes this antigen a possible target for radioimmunotherapy of colorectal micrometastases. In this study, the A33 antibody was labeled with the therapeutic nuclide (211)At using N-succinimidyl para-(tri-methylstannyl)benzoate (SPMB). The in vitro characteristics of the (211)At-benzoate-A33 conjugate ((211)At-A33) were investigated and found to be similar to those of (125)I-benzoate-A33 ((125)I-A33) in different assays. Both conjugates bound with high affinity to SW1222 cells (K(d) = 1.7 +/- 0.2 nM, and 1.8 +/- 0.1 nM for (211)At-A33 and (125)I-A33, respectively), and both showed good intracellular retention (70% of the radioactivity was still cell associated after 20 hours). The cytotoxic effect of (211)At-A33 was also confirmed. After incubation with (211)At-A33, SW1222 cells had a survival of approximately 0.3% when exposed to some 150 decays per cell (DPC). The cytotoxic effect was found to be dose-dependent, as cells exposed to only 56 DPC had a survival of approximately 5%. The (211)At-A33 conjugate shows promise as a potential radioimmunotherapy agent for treatment of micrometastases originating from colorectal carcinoma.
Collapse
Affiliation(s)
- Ylva Almqvist
- Department of Oncology, Radiology, and Clinical Immunology, Uppsala University, Uppsala, Sweden.
| | | | | | | | | | | | | |
Collapse
|
21
|
Unak P, Cetinkaya B. Absorbed dose estimates at the cellular level for 131I. Appl Radiat Isot 2005; 62:861-9. [PMID: 15799863 DOI: 10.1016/j.apradiso.2004.07.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Revised: 06/02/2004] [Accepted: 07/01/2004] [Indexed: 10/25/2022]
Abstract
Microdosimetric calculations of 131I have been evaluated for a single cell and for cell clusters. A VsBasic program has been used to calculate stopping power, linear energy transfer, range values and deposited energies per decay for beta particles, Auger and conversion electrons of 131I. The chemical composition of the cell has been taken into account in this model; results were compared with water medium. Besides, total absorbed doses have been calculated for the radionuclides distributed randomly within the cell and clusters. Cross-fire irradiation has been considered for clusters of cells. In this case, absorbed doses per cell within a cluster were found to be significantly higher than absorbed doses per single cell, depending on the cluster size. Results showed that 131I is a promising radionuclide for therapy of tumors from millimeter to centimeter dimensions.
Collapse
Affiliation(s)
- Perihan Unak
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Bornova, Izmir 35100, Turkey.
| | | |
Collapse
|
22
|
Malaroda A, Flux G, Ott R. The Application of Dose-Rate Volume Histograms and Survival Fractions to Multicellular Dosimetry. Cancer Biother Radiopharm 2005; 20:58-65. [PMID: 15778582 DOI: 10.1089/cbr.2005.20.58] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The distribution of therapeutic radiopharmaceuticals in volumes smaller than those that can be fully resolved by the imaging system, such as by PET and SPECT scanners, is usually assumed to be homogeneous. The aim of this study was to investigate the implications of such an assumption at a scale that can be defined as multicellular for heterogeneous activity localizations of (32)P, (90)Y, and (131)I. Dose-rate distributions from heterogeneous radioactivity uptakes have been calculated in cubic volumes of 1, 3, and 4 mm using the in-house software package DOVE. These have been studied by the use of dose-rate volume histograms, and the influence of the heterogeneous dose distribution on the treatment outcome has been analyzed by the calculation of Integral Survival Fractions. The results showed that the effect of the heterogeneous localization of the compound can be overridden by the amount of radioactivity administered. However, significant variations in the survival probability distributions have been observed, depending on the amount of initial activity considered, the activity configuration, the radionuclide, and the time over which the energy was deposited. It has been shown, for example, that the ability of longer-range beta emitters, such as (32)P and (90)Y, to invalidate heterogeneous dose-rate distributions may be negated by the decay rate of the radioactivity.
Collapse
Affiliation(s)
- Alessandra Malaroda
- Joint Department of Physics, Institute of Cancer Research and Royal Marsden Hospital, Sutton, UK.
| | | | | |
Collapse
|
23
|
Sundberg AL, Gedda L, Orlova A, Bruskin A, Blomquist E, Carlsson J, Tolmachev V. [177Lu]Bz-DTPA-EGF: Preclinical Characterization of a Potential Radionuclide Targeting Agent Against Glioma. Cancer Biother Radiopharm 2004; 19:195-204. [PMID: 15186600 DOI: 10.1089/108497804323071977] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Patients with glioblastoma multiforme have a poor prognosis due to recurrences originating from spread cells. The use of radionuclide targeting might increase the chance of inactivating single tumor cells with minimal damage to surrounding healthy tissue. As a target, overexpressed epidermal growth factor receptors (EGFR) may be used. A natural ligand to EGFR, the epidermal growth factor (EGF) is an attractive targeting agent due to its low molecular weight (6 kDa) and high affinity for EGFR. 177Lu (T(1/2) = 6.7 days) is a radionuclide well suited for treatment of small tumor cell clusters, since it emits relatively low-energy beta particles. The goal of this study was to prepare and preclinically evaluate both in vitro and in vivo the [177Lu]Bz-DTPA-EGF conjugate. The conjugate was characterized in vitro for its cell-binding properties, and in vivo for its pharmacokinetics and ability to target EGFR. [177Lu]Bz-DTPA-EGF bound to cultured U343 glioblastoma cells with an affinity of 1.9 nM. Interaction with EGFR led to rapid internalization, and more than 70% of the cell-associated radioactivity was internalized after 30 minutes of incubation. The retention of radioactivity was good, with more than 65% of the 177Lu still cell-associated after 2 days. Biodistribution studies of i.v. injected [177Lu]Bz-DTPA-EGF in NMRI mice demonstrated a rapid blood clearance. Most of the radioactivity was found in the liver and kidneys. The liver uptake was receptor-mediated, since it could be significantly reduced by preinjection of unlabeled EGF. In conclusion, [177Lu]Bz-DTPA-EGF seems to be a promising candidate for locoregional treatment of glioblastoma due to its high binding affinity, low molecular weight, and ability to target EGFR in vivo.
Collapse
|
24
|
Sundberg AL, Almqvist Y, Orlova A, Blomquist E, Jensen HJ, Gedda L, Tolmachev V, Carlsson J. Combined effect of gefitinib ('Iressa', ZD1839) and targeted radiotherapy with 211At-EGF. Eur J Nucl Med Mol Imaging 2003; 30:1348-56. [PMID: 12937952 DOI: 10.1007/s00259-003-1308-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2003] [Accepted: 07/19/2003] [Indexed: 12/20/2022]
Abstract
The EGFR-TKI (epidermal growth factor receptor tyrosine kinase inhibitor) gefitinib ['Iressa' (trademark of the AstraZeneca group of companies), ZD1839] increases the cellular uptake of radiolabelled epidermal growth factor (EGF). We investigated gefitinib treatment combined with astatine-211 EGF targeting in vitro using two cell lines expressing high levels of EGFR: A431 (sensitive to gefitinib) and U343MGaCl2:1 (resistant to gefitinib). In both cell lines, the uptake of 211At-EGF was markedly increased by concomitant treatment with gefitinib. Survival was investigated using both a clonogenic survival assay and a cell growth assay. Combined gefitinib and 211At-EGF treatment reduced the survival of U343 cells 3.5-fold compared with 211At-EGF alone. In A431 cells, 211At-EGF treatment resulted in very low survival, but combined treatment with gefitinib increased the survival by about 20-fold. These results indicate that combined treatment with gefitinib might increase the effect of ligand-mediated radionuclide therapy in gefitinib-resistant tumours and decrease the effect of such therapy in gefitinib-sensitive tumours.
Collapse
Affiliation(s)
- Asa Liljegren Sundberg
- Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Malaroda A, Flux GD, Buffa FM, Ott RJ. Multicellular dosimetry in voxel geometry for targeted radionuclide therapy. Cancer Biother Radiopharm 2003; 18:451-61. [PMID: 12954133 DOI: 10.1089/108497803322285215] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A software package to investigate absorbed doses and dose-rates at the cellular and multicellular scale has been developed that considers two- and three-dimensional activity distributions and makes use of analytical representations of the point-dose kernels for (131)I, (32)P, and (90)Y. This software allows cell assemblies to be simulated by definition of the number, size, and geometry of cells and their nuclei, and radionuclide uptake can be specified to occur within the nucleus, the cytoplasm, at the membrane, or within the extracellular space. The software has been validated at a cellular scale by comparison with results obtained using spherical geometry, as found in the literature. At a multicellular scale, comparisons were made with a Monte Carlo simulation in voxel geometry. The software has been designed to work within a user-defined voxel geometry. This geometry is useful not only to simulate complex cell assemblies and realistic heterogeneous radionuclide distributions, but will also allow the use of histological and autoradiographic data. Absorbed dose distributions for a single cell calculated using this code varied significantly with activity localization within the cell, and to a lesser extent, with the cellular geometry. At a multicellular level, a two-dimensional heterogeneous activity distribution inferred from a two-dimensional image of a slice throughout a spheroid was used to calculate a dose-rate distribution. This resulted in a heterogeneous dose-rate delivery even for longer-range radionuclides such as (90)Y and (32)P.
Collapse
Affiliation(s)
- A Malaroda
- Joint Dept. of Physics, Institute of Cancer Research and Royal Marsden Hospital, London, UK.
| | | | | | | |
Collapse
|
26
|
Sundberg AL, Blomquist E, Carlsson J, Steffen AC, Gedda L. Cellular retention of radioactivity and increased radiation dose. Model experiments with EGF-dextran. Nucl Med Biol 2003; 30:303-15. [PMID: 12745022 DOI: 10.1016/s0969-8051(02)00421-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Targeting of tumor cells with radiolabeled biomolecules is a possible approach to inactivate disseminated tumor cells. However, rapid degradation of the biomolecules after cellular internalization and subsequent excretion of the radioactivity is a problem. We studied the possibility of using dextran as a carrier of radionuclides to improve the intracellular retention. An EGF-dextran conjugate, aimed for targeting of tumor cells overexpressing the EGF-receptor, was used as model. Retention tests were performed with (125)I on different parts: [(125)I]-EGF-dextran-[(125)I], [(125)I]-EGF-dextran and EGF-dextran-[(125)I]. Comparisons were made with [(125)I]-EGF. The radiolabeled compounds were incubated with cultured glioma cells for different times. The cellular retention of radioactivity was then measured for up to 24 h. Expected radiation doses at the cellular level were calculated assuming that (131)I, instead of (125)I, was coupled to EGF and EGF-dextran. The results indicated that the EGF-part of the conjugate was degraded and the EGF-attached radioactivity was rapidly excreted, whereas radioactivity on dextran was retained intracellularly to a high degree, i.e. 70-80% of the radioactivity bound to dextran was still cell-associated after 24 h. The retention after 24 h was significantly higher (p < 0.001) when the radioactivity was on the dextran instead of the EGF-part. The radiolabeled EGF-dextran had a notably high specific radioactivity; up to 11 MBq/microg. There was potential for at least hundred times increased radiation dose per receptor interaction when the radioactivity was on the dextran part. The advantage with radioactivity on the dextran part was the high cellular retention and the high specific radioactivity (higher than previously reported for other residualizing labels) without severe loss of receptor specific binding. Thus, dextran seems suitable as a carrier of radionuclides aimed for therapy and gives potential for a highly increased radiation dose.
Collapse
Affiliation(s)
- Asa Liljegren Sundberg
- Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University, Sweden
| | | | | | | | | |
Collapse
|
27
|
Kullberg EB, Nestor M, Gedda L. Tumor-cell targeted epiderimal growth factor liposomes loaded with boronated acridine: uptake and processing. Pharm Res 2003; 20:229-36. [PMID: 12636161 DOI: 10.1023/a:1022223204460] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE The aim of this work was to investigate the cellular binding and processing of polyethylene glycol-stabilized epidermal growth factor (EGF) liposomes. The liposomes were actively loaded with water-soluble boronated acridine (WSA), primarily developed for boron neutron capture therapy. METHODS The uptake, internalization, and retention of EGF-liposome conjugates were studied in two cultured monolayer cell-lines, A-431 and U-343, with regard to the nuclide-label on the targeting agent, the carrier, and the load. The subcellular localization of WSA was studied using confocal microscopy. RESULTS We found that the liposome complex was internalized after specific binding to the EGF receptor. After internalization in the tumor cells, WSA was distributed mainly in the cytoplasm and was shown to have long cellular retention, with 80% of the boron remaining after 48 h. CONCLUSIONS The long retention of the compound and the cellular boron concentration reached makes these targeted liposomes interesting for further development toward boron neutron capture therapy.
Collapse
Affiliation(s)
- Erika Bohl Kullberg
- Division of Biomedical Radiation Sciences, Department of Oncology, Radiology and Clinical Immunology, Rudbeck Laboratory, Uppsala University, S-751 85 Uppsala, Sweden.
| | | | | |
Collapse
|
28
|
Carlsson J, Forssell Aronsson E, Hietala SO, Stigbrand T, Tennvall J. Tumour therapy with radionuclides: assessment of progress and problems. Radiother Oncol 2003; 66:107-17. [PMID: 12648782 DOI: 10.1016/s0167-8140(02)00374-2] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Radionuclide therapy is a promising modality for treatment of tumours of haematopoietic origin while the success for treatment of solid tumours so far has been limited. The authors consider radionuclide therapy mainly as a method to eradicate disseminated tumour cells and small metastases while bulky tumours and large metastases have to be treated surgically or by external radiation therapy. The promising therapeutic results for haematological tumours give hope that radionuclide therapy will have a breakthrough also for treatment of disseminated cells from solid tumours. New knowledge related to this is continuously emerging since new molecular target structures are being characterised and the knowledge on pharmacokinetics and cellular processing of different types of targeting agents increases. There is also improved understanding of the factors of importance for the choice of appropriate radionuclides with respect to their decay properties and the therapeutic applications. Furthermore, new methods to modify the uptake of radionuclides in tumour cells and normal tissues are emerging. However, we still need improvements regarding dosimetry and treatment planning as well as an increased knowledge about the tolerance doses for normal tissues and the radiobiological effects on tumour cells. This is especially important in targeted radionuclide therapy where the dose rates often are lower than 1Gy/h.
Collapse
Affiliation(s)
- Jörgen Carlsson
- Department of Oncology, Radiology and Clinical Oncology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden
| | | | | | | | | |
Collapse
|
29
|
Vicente MGH, Nurco DJ, Shetty SJ, Osterloh J, Ventre E, Hegde V, Deutsch WA. Synthesis, dark toxicity and induction of in vitro DNA photodamage by a tetra(4-nido-carboranylphenyl)porphyrin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2002; 68:123-32. [PMID: 12468207 DOI: 10.1016/s1011-1344(02)00383-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The total synthesis of tetra(4-carboranylphenyl)porphyrins 4 and 6 and their zinc(II) complexes 5 and 7 are described. These compounds were characterized by analytical and spectroscopic methods and, in the case of 5, by X-ray crystallography. The water-soluble nido-carboranylporphyrins 6 and 7 were found to have low dark toxicity towards V79 hamster lung fibroblast cells, using a clonogenic assay (50% colony survival, CS(50)>300 microM). Upon light activation nido-carboranylporphyrin 6 effectively induced DNA damage in vitro. Two different methods were used to assess the extent of DNA damage: the super-coiled to nicked DNA and the alkaline Comet assay using human leukemia K562 cells. Significant PDT-induced DNA damage was observed for porphyrin 6 using both assays, compared to light-only and porphyrin-only experiments. It is concluded that this type of nido-carboranylporphyrin is a promising sensitizer for both the boron neutron capture therapy and the photodynamic therapy of tumors.
Collapse
Affiliation(s)
- M G H Vicente
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA.
| | | | | | | | | | | | | |
Collapse
|
30
|
Li WB, Friedland W, Pomplun E, Jacob P, Paretzke HG, Lassmann M, Reiners C. Track structures and dose distributions from decays of (131)I and (125)I in and around water spheres simulating micrometastases of differentiated thyroid cancer. Radiat Res 2001; 156:419-29. [PMID: 11554854 DOI: 10.1667/0033-7587(2001)156[0419:tsaddf]2.0.co;2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The disintegration of the radionuclides (131)I and (125)I and the subsequent charged-particle tracks left behind in water (as a model substance for a biological cell) are simulated by the Monte Carlo track structure simulation code PARTRAC, using new inelastic electron scattering cross sections for condensed water. Every photon and electron emitted was followed in detail, event by event, down to 10 eV. From the spatial information on the track structures, absorbed dose distributions per (131)I and (125)I decay were calculated in and around water spheres simulating micrometastases as well as in the tissue surrounding such metastases. These radionuclides were assumed to be distributed uniformly inside spheres of different diameters (0.01, 0.03, 0.1, 0.3, 1.0 and 3.0 mm). The respective electron degradation spectra, the nearest-neighbor distance distributions between inelastic events, and the distance distributions for all activations for both iodine radionuclides were calculated. The absorbed fractions of the initial electron energies, absorbed doses and energy depositions, and single-event distributions, F(1)(epsilon), inside the six water spheres described above and in the surrounding tissue were also calculated. The absorbed doses per decay inside the six water spheres, i.e., the calculated S values (listed from 0.01 to 3.0 mm), were 6.8 x 10(-4), 7.2 x 10(-5), 5.5 x 10(-6), 4.9 x 10(-7), 3.1 x 10(-8) and 1.8 x 10(-9) Gy Bq(-1) s(-1) for (131)I, and 3.4 x 10(-3), 1.7 x 10(-4), 5.1 x 10(-6), 2.0 x 10(-7), 5.6 x 10(-9) and 2.2 x 10(-10) Gy Bq(-1) s(-1) for (125)I. It is concluded that, in the treatment of thyroid cancer, the geometrical track structure properties of (125)I might be superior to those of (131)I in micrometastases with diameters less than 0.1 mm; however, in this medical context, many other factors also have to be considered.
Collapse
Affiliation(s)
- W B Li
- GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg, Germany.
| | | | | | | | | | | | | |
Collapse
|