Radioactive holmium phosphate microspheres for cancer treatment

The aim of this study was the development of radioactive holmium phosphate microspheres (HoPO4-MS) with a high holmium content and that are stable in human serum for selective internal radiation therapy (SIRT) of liver cancer. To this end, holmium acetylacetonate microspheres (HoAcAc-MS) were prepared (34.2 ± 1.0 µm in diameter, holmium content of 46.2 ± 0.8 and density of 1.7 g/cm3) via an emulsification and solvent evaporation method. The concentration of HoAcAc in the organic solvent, the temperature of emulsification and the stirring speed were varied for the preparation of the HoAcAc-MS to obtain microspheres with different diameters ranging from 11 to 35 µm. Subsequently, the AcAc ligands of the HoAcAc-MS were replaced by phosphate ions by simply incubating neutron irradiated HoAcAc-MS in a phosphate buffer solution (0.116 M, pH 4.2) to yield radioactive HoPO4-MS. The obtained microspheres were analyzed using different techniques such as SEM-EDS, ICP-OES and HPLC. The prepared HoPO4-MS (29.5 ± 1.2 µm in diameter and a density of 3.1 g/cm3) present an even higher holmium content (52 wt%) than the HoAcAc-MS precursor (46 wt%). Finally, the stability of the HoPO4-MS was tested by incubation in human serum at 37 °C which showed no visible changes of the microspheres morphology and only 0.1% of holmium release was observed during the 2 weeks period of incubation. In conclusion, this study shows that stable radioactive HoPO4-MS can be prepared with suitable properties to be used for cancer therapy

Preparation and characterization of inorganic radioactive holmium-166 microspheres for internal radionuclide therapy

Microspheres with high specific activities of radionuclides are very interesting for internal radiotherapy treatments. This work focuses on the formulation and characterization of inorganic microspheres with a high content of holmium and therefore a high specific radioactivity of holmium-166. Two novel formulations of inorganic microspheres were obtained by dispersing solid holmium acetylacetonate microspheres (Ho2(AcAc)3-ms) in NaH2PO4 or NaOH solutions followed by 2 h incubation at room temperature. By exchange of acetylacetonate with phosphate or hydroxyl ions, holmium phosphate microspheres (HoPO4-ms) and holmium hydroxide microspheres (Ho(OH)3-ms) were formed respectively. The inorganic microspheres had a significantly smaller diameter (28.5 ± 4.4 μm (HoPO4-ms) and 25.1 ± 3.5 μm (Ho(OH)3-ms)) than those of Ho2(AcAc)3-ms (32.6 ± 5.2 μm). The weight percentage of holmium-165 in the microspheres increased significantly from 47% (Ho2(AcAc)3-ms) to 55% (HoPO4-ms) and 73% (Ho(OH)3-ms). After preparation of both HoPO4-ms and Ho(OH)3-ms, the stable holmium-165 isotope was partly converted by neutron activation into radioactive holmium-166 to yield radioactive microspheres. High specific activities were achieved ranging from 21.7 to 59.9 MBq/mg (166HoPO4-ms) and from 28.8 to 79.9 MBq/mg (166Ho(OH)3-ms) depending on the neutron activation time. The structure of both microspheres was preserved up to neutron activations of 6 h in a thermal neutron flux of 4.72 × 1016 n m-2 s-1. After activation, both microspheres revealed excellent stability in administration fluids (saline and phosphate buffer) having less than 0.05% of holmium released after 72 h incubation. Finally, the hemocompatibility of these inorganic microspheres was evaluated and it was shown that the microspheres did cause neither hemolysis nor depletion or inhibition of the coagulation factors of the intrinsic blood coagulation pathway meaning that the microspheres have a good hemocompatibility. Overall, this work shows that radioactive inorganic microspheres with high specific activities of holmium-166 can be prepared which potentially can be used for internal radionuclide therapy

Radioactive holmium phosphate microspheres for cancer treatment

The aim of this study was the development of radioactive holmium phosphate microspheres (HoPO4-MS) with a high holmium content and that are stable in human serum for selective internal radiation therapy (SIRT) of liver cancer. To this end, holmium acetylacetonate microspheres (HoAcAc-MS) were prepared (34.2 ± 1.0 µm in diameter, holmium content of 46.2 ± 0.8 and density of 1.7 g/cm3) via an emulsification and solvent evaporation method. The concentration of HoAcAc in the organic solvent, the temperature of emulsification and the stirring speed were varied for the preparation of the HoAcAc-MS to obtain microspheres with different diameters ranging from 11 to 35 µm. Subsequently, the AcAc ligands of the HoAcAc-MS were replaced by phosphate ions by simply incubating neutron irradiated HoAcAc-MS in a phosphate buffer solution (0.116 M, pH 4.2) to yield radioactive HoPO4-MS. The obtained microspheres were analyzed using different techniques such as SEM-EDS, ICP-OES and HPLC. The prepared HoPO4-MS (29.5 ± 1.2 µm in diameter and a density of 3.1 g/cm3) present an even higher holmium content (52 wt%) than the HoAcAc-MS precursor (46 wt%). Finally, the stability of the HoPO4-MS was tested by incubation in human serum at 37 °C which showed no visible changes of the microspheres morphology and only 0.1% of holmium release was observed during the 2 weeks period of incubation. In conclusion, this study shows that stable radioactive HoPO4-MS can be prepared with suitable properties to be used for cancer therapy

Radioactive holmium phosphate microspheres for cancer treatment

The aim of this study was the development of radioactive holmium phosphate microspheres (HoPO4-MS) with a high holmium content and that are stable in human serum for selective internal radiation therapy (SIRT) of liver cancer. To this end, holmium acetylacetonate microspheres (HoAcAc-MS) were prepared (34.2 ± 1.0 µm in diameter, holmium content of 46.2 ± 0.8 and density of 1.7 g/cm3) via an emulsification and solvent evaporation method. The concentration of HoAcAc in the organic solvent, the temperature of emulsification and the stirring speed were varied for the preparation of the HoAcAc-MS to obtain microspheres with different diameters ranging from 11 to 35 µm. Subsequently, the AcAc ligands of the HoAcAc-MS were replaced by phosphate ions by simply incubating neutron irradiated HoAcAc-MS in a phosphate buffer solution (0.116 M, pH 4.2) to yield radioactive HoPO4-MS. The obtained microspheres were analyzed using different techniques such as SEM-EDS, ICP-OES and HPLC. The prepared HoPO4-MS (29.5 ± 1.2 µm in diameter and a density of 3.1 g/cm3) present an even higher holmium content (52 wt%) than the HoAcAc-MS precursor (46 wt%). Finally, the stability of the HoPO4-MS was tested by incubation in human serum at 37 °C which showed no visible changes of the microspheres morphology and only 0.1% of holmium release was observed during the 2 weeks period of incubation. In conclusion, this study shows that stable radioactive HoPO4-MS can be prepared with suitable properties to be used for cancer therapy

Preparation and characterization of inorganic radioactive holmium-166 microspheres for internal radionuclide therapy

Microspheres with high specific activities of radionuclides are very interesting for internal radiotherapy treatments. This work focuses on the formulation and characterization of inorganic microspheres with a high content of holmium and therefore a high specific radioactivity of holmium-166. Two novel formulations of inorganic microspheres were obtained by dispersing solid holmium acetylacetonate microspheres (Ho2(AcAc)3-ms) in NaH2PO4 or NaOH solutions followed by 2 h incubation at room temperature. By exchange of acetylacetonate with phosphate or hydroxyl ions, holmium phosphate microspheres (HoPO4-ms) and holmium hydroxide microspheres (Ho(OH)3-ms) were formed respectively. The inorganic microspheres had a significantly smaller diameter (28.5 ± 4.4 μm (HoPO4-ms) and 25.1 ± 3.5 μm (Ho(OH)3-ms)) than those of Ho2(AcAc)3-ms (32.6 ± 5.2 μm). The weight percentage of holmium-165 in the microspheres increased significantly from 47% (Ho2(AcAc)3-ms) to 55% (HoPO4-ms) and 73% (Ho(OH)3-ms). After preparation of both HoPO4-ms and Ho(OH)3-ms, the stable holmium-165 isotope was partly converted by neutron activation into radioactive holmium-166 to yield radioactive microspheres. High specific activities were achieved ranging from 21.7 to 59.9 MBq/mg (166HoPO4-ms) and from 28.8 to 79.9 MBq/mg (166Ho(OH)3-ms) depending on the neutron activation time. The structure of both microspheres was preserved up to neutron activations of 6 h in a thermal neutron flux of 4.72 × 1016 n m-2 s-1. After activation, both microspheres revealed excellent stability in administration fluids (saline and phosphate buffer) having less than 0.05% of holmium released after 72 h incubation. Finally, the hemocompatibility of these inorganic microspheres was evaluated and it was shown that the microspheres did cause neither hemolysis nor depletion or inhibition of the coagulation factors of the intrinsic blood coagulation pathway meaning that the microspheres have a good hemocompatibility. Overall, this work shows that radioactive inorganic microspheres with high specific activities of holmium-166 can be prepared which potentially can be used for internal radionuclide therapy

CIGR E-Journal Volume 7

Peer Reviewed Original Research Articles --- 1.) A. Tambunan, Y. Sagara, Y. Seo, and Y. Kawagoe. Image Analysis on Temperature Distribution within Lettuce Undergoing Vacuum Cooling. Manuscript FP 04 002. Vol. VII. January 2005. --- 2.) S. Nimmermark and G. Gustafsson. Influence of Temperature, Humidity, and Ventilation Rate on the Release of Odour and Ammonia in a Floor Housing System for Laying Hens. Manuscript BC 04 008. Vol. VII. March 2005. --- 3.) S. Hassan-Beygi and B. Ghobadian. Noise Attenuation Characteristics of Different Road Surfaces During Power Tiller Transport. Manuscript PM 04 009. Vol.VII. March 2005. 4.) L. Pan, P. Shao, and S. Jiang. Separation of Phytosterol and Synthesized VE Succinate from Rapeseed Oil Deodorizer Distillate. Manuscript FP 04 010. March 2005. --- 5.) S. Shrestha, F. Kazama, Y. Sakamoto, and S. Bastola. Statistical Modeling of Pollutant Load in Subbasins of the Fuji River Basin, Japan. Manuscript LW 05 001. Vol. VII. March, 2005. --- 6.) M. Rijo and C. Arranja. Hydraulic Performance of a Downstream Controlled Irrigation Canal Equipped with Different Offtake Types. Manuscript LW 04 014. Vol. VII. March, 2005. --- 7.) J. Krahl, A. Munack, O. Schroeder, H. Stein, L. Herbst, A. Kaufmann, and J. Buenger. Fuel Design as Constructional Element with the Example of Biogenic and Fossil Diesel Fuels. Manuscript EE 04 008. Vol. VII. March, 2005. --- 8.) M. Aradas, I. Naas, and D. Salgado. Comparing the Thermal Environment in Broiler Houses Using Two Bird Densities Under Tropical Conditions. Manuscript BC 03 017. Vol. VII. March, 2005. 9.) N. Kyei-Baffour. The Effect of Quality of Rising Capillary Water on Soil Surface Sodicity. Manuscript LW 04 013. April, 2005. 10.) P. Soni, V. Salokhe, and H. Tantau. Effect of Screen Porosity on Selected Microclimatic Parameters of Naturally Ventilated Tropical Greenhouses. Manuscript BC 05 002. Vol. VII. April, 2005. --- 11.) I. Naas, S. Campos, and K. Silva. Comparison of Manual and Electronic Traceability in Swine Production. Manuscript IT 05 001. Vol. VII. April, 2005. --- 12.) V. Assaad, J. Jofriet, S. Negi, and G. Hayward. Corrosion of Reinforced Concrete Specimens Exposed to Hydrogen Sulfide and Sodium Sulfate. Manuscript BC 03 013. Vol. VII. April, 2005. 13.) S. Sivakumar, R. Manian, K. Kathirvel, and G. Raghavan. Investigation on the Influence of Machine and Operational Parameters for the Development of a Manually-Drawn Rice Seeder for Direct Sowing. Manuscript PM 04 008. Vol. VII. May, 2005. --- 14.) S. Jekayinfa and O. Omisakin. The Energy Potentials of some Agricultural Wastes as Local Fuel Materials in Nigeria. Manuscript EE 05 003. Vol. VII. May, 2005. --- 15.) S. Pedersen, S. Morsing, and J. Strom. Simulation of Heat Requirement and Air Quality in Weaner Houses for Three Climate Regions Using CIGR 2002 Heat Production Equations. Manuscript BC 05 001. Vol. VII. June, 2005. --- 16.) V. Carvalho, I. Naas, M. Mollo, and V. Massafera. Prediction of the Occurrence of Lameness in Dairy Cows using a Fuzzy-Logic Based Expert System??t I. Manuscript IT 05 002. Vol. VII. June, 2005. --- 17.) H. Pandorfi and I. Da Silva. Evaluation of the Behavior of Piglets in Different Heating Systems using Analysis of Image and Electronic Identification. BC 03 021. Vol. VII. August, 2005. 18.) T. Ozturk and M. Bayrakh. The Possibilities of using Tobacco Wastes in Producing Lightweight Concrete. Manuscript BC 05 006. Vol. VII. August, 2005. --- 19.) P. Goodrich, D. Schmidt, and D. Haubenschild. Anaerobic Digestion for Energy and Pollution Control. Manuscript EE 03 001. Vol. VII. August, 2005. --- 20.) W. Lee, J. Schueller, and T. Burks. Wagon-Based Silage Yield Mapping System. Manuscript IT 05 003. Vol. VII. August, 2005. 21.) M. Heinloo, T. Leola, and V. Veinla. Synthesis of the Manipulator for the Scraper of a Press Manure Removal. Manuscript MES 05 002. Vol. VII. August, 2005. --- 22.) T. Tomson and A. Annuk. Wind Energy in Estonian Western Highlands. Manuscript EE 04 001. Vol. VII. September, 2005. --- 23.) G. Bora, M. Schrock, D. Oard, J. Grimm, and T. Kolb. Performance of a Stacked Valve Multipoint Pulse Width Modulation (PWM) Manifold for Variable Rate Anhydrous Ammonia Application. Manuscript PM 05 005. Vol.VII. September, 2005. --- 24.) E. Quendler, P. Veith, A. Pohl, and J. Boxberger. More Security for Kids Around Moving Vehicles on Farms. Manuscript SAFETY 05 001. Vol. VII. September, 2005. --- 25.) M. Queiroz, I. Naas, C. Sampaio. Estimating Thermal Comfort for Piglets Considering Ammonia Concentration. Manuscript IT 05 004/BC 05 005. Vol. VII. September, 2005. --- 26.) S. Ojolo and A. Bamgboye. Thermochemical Conversion of Municipal Solid Waste to Produce Fuel and Reduce Waste. Manuscript EE 05 006. Vol. VII. September, 2005. --- 27.) Y. Mijinyawa and J. Adetunji. Evaluation of Farm Transportation System in Osun and Oyo States of Nigeria. Manuscript LW 05 004. Vol. VII. September, 2005. --- 28.) S. Morsing, S. Pedersen, J. Strom, and L. Jacobsen. Energy Consumption and Air Quality in Growing-Finishing Pig Houses for Three Climate Regions Using CIGR 2002 Heat Production Equations. Manuscript BC 05 007. Vol. VII. September, 2005. --- 29.) R. Schmersahl and V. Scholz. Testing a PEM Fuel Cell System with Biogas Fuel. Manuscript EE 05 002. Vol. VII. September, 2005. --- 30.) U. Mutwiwa and H. Tantau. Suitability of a UV Lamp for Trapping the Greenhouse Whitefly Trialeurodes vaporariorum Westwood (Hom: Aleyrodidae). Manuscript BC 05 004. Vol. VII. September, 2005. --- 31.) S. Kazemi, N. Wang, M. Ngadi, and S. Prasher. Evaluation of Frying Oil Quality Using VIS/NIR Hyperspectral Analysis. Manuscript FP 05 001. Vol. VII. September, 2005. --- 32.) W. Reimann. Down Streaming of Lactic Acid from Hydrolysate of Barley after Fermentation. Manuscript FP 05 004. Vol. VII. September, 2005. --- 33.) B. Sarkar and G. Tiwari. Thermal Modeling of a Greenhouse Fish Pond System. Manuscript BC 05 015. Vol. VII. October, 2005. 34.) S. Ido and M. Bux. Prediction of Evaporation Rate in a Solar Dryer for Sewage Sludge. Manuscript EE 05 009. Vol. VII. October, 2005. --- 35.) U. Dhakal, V. Salokhe, H. Tantau, and J. Max. Development of a Greenhouse Nutrient Recycling System for Tomato Production in the Humid Tropics. Manuscript BC 05 008. Vol. VII. October, 2005. --- 36.) E. Ajav and B. Adejumo. Performance Evaluation of an Okra Thresher. Manuscript PM 04 006. Vol. VII. October, 2005. --- 37.) K. Patil, T. Bowser, D. Bellmer, and R. Huhnke. Fluidization Characteristics of Sand and Chopped Switchgrass-Sand Mixtures. Manuscript EE 04 005. Vol. VII. October, 2005. --- 38.) S. Al-Kufaishi, S. Blackmore, H. Sourell, and G. Maletti. Assessment of Two Variable Rate Irrigation Controllers used on a Centre-Pivot. Manuscript LW 05 002. Vol. VII. October, 2005. --- 39.) P. Maly, T. Hoffman, and Ch. Furll. Gentle Harvest of Potatoes in Storage Boxes. Manuscript FP 05 002. Vol. VII. October, 2005. --- 40.) M. Reza Ehsani, C. Divaker Durairaj, S. Woods, and M. Sullivan. Potential Application of Electrical Conductivity(EC) Map for Variable Rate Seeding. Manuscript IT 05 006. Vol. VII. November, 2005. --- 41.) O. Kitani, K. Roy, M. Yoshida, and R. Endo. Control of Water Environment of Plants using Waste Biomass. Manuscript LW 05 007. Vol. VII. November, 2005. --- 42.) J. Hou, Y. Qian, G. Lui, and R. Dong. The Influence of Temperature, pH, and C/N Ratio on the Growth and Survival of Earthworms in Municipal Solid Waste. Manuscript FP 04 014. Vol VII. November, 2005. --- 43.) G. Gustafsson, K-H. Jeppsson, J. Hultgren, and J-O. Sanno. Techniques to Reduce the Ammonia Release from a Cowshed with Tied Dairy Cattle. Manuscript BC 04 010. Vol. VII. November, 2005. --- 44.) K. Hassenberg and Chr. Idler. Influence of Washing Method on the Quality of Prepacked Iceberg Lettuce. Manuscript FP 05 003. Vol. VII. November, 2005. --- 45.) E. Mamman and K. Oni. Draught Performance of a Range of Model Chisel Furrowers. Manuscript PM 05 003. Vol. VII. November, 2005. --- 46.) E. Mamman, B. Umar, and N. Aviara. Effect of Moisture Content and Loading Orientation on the Mechanical Properties of Balanites Aegyptiaca Nuts. Manuscript FP 04 015. Vol. VII. December, 2005. --- 47.) Y. Yiljep, G. Fumen, and E. Ajisegiri. The Effects of Peeling, Splitting and Drying on Ginger Quality and Oil/oleoresin Content. Manuscript FP 05 009. Vol. VII. December, 2005. --- 48.) Y. Yiljep and U. Mohammed. Effect of Knife Velocity on Cutting Energy and Efficiency during Impact Cutting of Sorghum Stalk. Manuscript PM 05 004. Vol. VII. December, 2005. --- 49.) G. Gustafsson and E. von Wachenfelt. Measures against Ammonia Release in a Floor Housing System for Laying Hens. Manuscript BC 05 003. Vol. VII. December, 2005. --- 50.) A. Prochnow, M. Heiermann, A. Drenckhan, and H. Schelle. Seasonal Pattern of Biomethanisation of Grass from Landscape Managemant. Manuscript EE 05 011. Vol. VII. December, 2005. --- 51.) A. Wagner and W. Buescher. Compression Characteristics of Wilted Grass. Manuscript IT 05 007. Vol. VII. December, 2005. --- 52.) H. Kushwaha, A. Srivastava, and H. Singh. Development and Performance Evaluation of an Okra Seed Extractor. Manuscript PM 05 001. Vol. VII. December, 2005. ---- 53.) P. Mahnert, M. Heiermann, and B. Linke. Batch- and Semicontinuous Biogas Production from Different Grass Species. Manuscript EE 05 010. Vol. VII. December, 2005. --- Invited Overview Articles --- 1.) L. Pereira. Water and Agriculture: Facing Water Scarcity and Environmental Challenges. Invited Overview. Vol. VII. February 2005. --- 2.) A. Raji and A. Olamutu. Prospects of Computer Vision Automated Sorting Systems in Agricultural Process Operations in Nigeria. Invited Overview. Vol. VII. February 2005. --- 3.) J. Yuan. The Status of China's Agricultural Machinery Industry and the Prospects for International Cooperation. Invited Overview. Club of Bologna. Vol. VII. March, 2005. --- 4.) S. Li. Agricultural Mechanization Promotion in China-Current Situation and Future. Invited Overview. Club of Bologna. Vol. VII. March, 2005. --- 5.) G. Gavioli. Cost Benefits of the Platform Principles for Tractors and Other Agricultural Machinery. Invited Overview. Club of Bologna. Vol. VII. March, 2005. --- 6.) G. Gavioli. Cost Benefits of the Platform Principles for Tractors and Other Agricultural Machinery. Invited Overview. Power Point Slides. Club of Bologna. Vol. VII. March, 2005. --- 7.) A. Segre and H. Petrics. EU Enlargement and its Influence on Agriculture and Mechanisation. Invited Overview. Club of Bologna. Vol. VII. March, 2005. --- 8.) E. Gasparetto. Conclusions and recommendations. Invited Overview. Club of Bologna. Vol. VII. March, 2005. --- 9.) J. Ullman. Remedial Activities to Reduce Atmospheric Pollutants from Animal Feeding Operations. Invited Overview. Vol. VII. June, 2005. --- 10.) Y. Mijinyawa. Agricultural Engineering Education in Nigeria. Invited Overview. Vol. VII. August. 2005

Microalgal Biomass of Industrial Interest: Methods of Characterization

International audienceMicroalgae represent a new source of biomass for many applications. The advantage of microalgae over higher plants is their high productivities. The photoautotrophic microalgae include all photosynthetic microorganisms, i.e. Cyanobacteria (prokaryotes) or microalgae (eukaryotes). These microorganisms are characterized by a large biodiversity and chimiodiversity. Then, the analysis of microalgal and cyanobacterial biomass often needs specific adaptations of the classical protocols for extraction as well as for quantification of their contents. This chapter reviewed the main analytical methods used for the analysis of microalgae biomass and its main vaporizable compounds: proteins, polysaccharides, lipids, pigments and secondary metabolites