TY - JOUR T1 - Investigation of new 32P-CP-PLLA microparticle in the treatment of pancreatic cancer mice JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1573 LP - 1573 VL - 50 IS - supplement 2 AU - Min Yang AU - Dong Pan AU - Yu Xu AU - Li Wang AU - Shi Luo Y1 - 2009/05/01 UR - http://jnm.snmjournals.org/content/50/supplement_2/1573.abstract N2 - 1573 Objectives L-Polylactide (PLLA) is a good biocompatibility and biodegradable polymer. 32P-chromic phosphate-L-polylactide (32P-CP-PLLA) microparticle is a new control release preparation of the therapy radionuclide 32P. The objective of the study is to compare systemic distribution and effective therapy of 32P-CP colloidal and new 32P- CP-PLLA microparticle. Methods 32P-CP-PLLA microparticles were prepared by SED process. The microparticle exhibits as a cylinder, the diameter length, height and mass were 0.85~0.9 mm, 2.2~2.5mm and 0.9~1.1mg, respectively. Nude mice with pancreatic cancerxenograft were divided into seven groups randomly. Group A: 3.7MBq 32P-CP colloidal; group B: 3.7MBq 32P-CP-PLLA microparticles; group C: 7.4MBq 32P-CP-PLLA microparticles; group D: 18.5MBq 32P-CP-PLLA microparticles; group E: 37MBq 32P-CP-PLLA microparticles; group F: 74MBq 32P-CP-PLLA; group G: untreated mice. The tumor and other interesting organs of group A and B were counted for radioactivity at 24h, 8d and 16d post implantation. Body weight, complete blood count and tumor volume of each group were monitoredfor 4 weeks post implantation. Results Maximum tolerated dose of the microparticle was determined as 3700 MBq/kg. The radioactivity in the 32P-CP-PLLA microparticles were restrained fully in the tumor, while 32P colloid may diffuse from tumor to other organs after injecting into tumors. Body weight andplatelet counts recover to baseline value by 4 weeks. Conclusions The new microparticle could restrain diffusion of colloidal 32P from tumor to the other outer-tumor organs and deposit colloidal 32P in the tumors for longer time, therefor decrease the systemic distribution and side effect. Tumor growth control was successfully achieved with the new dosage form. Research Support National 863 Program 2007AA02Z471 ER -