Retention Characteristics of Tc-99m-Pullulan-Derivatives in CT26 Tumor of Mice.
- Author:
Young Jun HEO
1
;
Ho Chun SONG
;
Hee Seung BOM
;
Kun NA
;
Seong Min KIM
Author Information
1. Department of Nuclear Medicine, Chonnam National University Hospital, Gwangju, Korea. hsbom@jnu.ac.kr
- Publication Type:Original Article
- Keywords:
Pullulan derivatives;
Tc-99m;
mouse;
CT26;
retention
- MeSH:
Animals;
Body Image;
Colonic Neoplasms;
Hydrogel;
Injections, Subcutaneous;
Mice*;
Nanoparticles;
Osmolar Concentration;
Radioisotopes;
Sodium Pertechnetate Tc 99m
- From:Korean Journal of Nuclear Medicine
2003;37(6):393-401
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVE: Pullulan derivatives (PD) can be used to make self-assembled hydrogel nanoparticles which are responsive to ionic strength. The aim of this study is to evaluate the potential of PD as a retaining carrier of radioisotope inside tumors. MATERIALS AND METHODS: Four types of PD were evaluated which included pullulan acetate (PA), succinylated PA (SPA), PA-DTPA and SPA-DTPA conjugates. They were radiolabeled with Tc-99m. Labelling efficiencies were determined at 30 min, 1, 2, 4 and 12 hours after radiolabeling. CT-26 colon cancer cells were subcutaneously injected into Balb/c mice. After 2 weeks of subcutaneous injection, Tc-99m-labelled PD (Tc-99m-PD) were injected into the tumors. Whole body images of mice were obtained at 30 min, 1, 2, and 12 hr after intratumoral injection. All twenty mice were grouped into four groups by largest diameter; control A (largest diameter = 5 mm, n = 5), control B (largest diameter = 10 mm, n = 5), pullulan A (largest diameter = 5 mm, n = 5), pllulan B (largest diameter = 10 mm, n = 5). Dynamic images were obtained for 1 hour after intratumoral injection. Static images were obtained at 1 hr, 2 hr, 3 hr and 4 hr after intratumoral injection with Tc-99m pertechnetate and Tc-99m-PA. Target-to-background ratios and retention rates were calculated. RESULTS: Labeling efficiencies of PA, SPA, PA-DTPA and SPA-DTPA were 94.5 +/- 5.9%, 97.8 +/- 3.5% 94.2 +/- 3.8%, and 92.5 +/- 6.2%, respectively (p> 0.05). Percent retention rates (%RR) of PA and PA-DTPA were significantly higher than those of control, however, those of SP-DTPA and SPA became similar to control at 4 and 12 hr, respectively. %RR of pullulan A and pullulan B at 1, 4 and 8 hr is significantly higher than that of control (p < 0.05). However, %RR between pullulan A and pullulan B were similar. CONCLUSION: The ionic strength dependent PD-nanoparticles are retained in the tumor. No difference of %RR according to tumor size was noted. Therapeutic application of PD labelled with beta- or alpha- emitting radionuclides can be expected.
