**2.7 Study of kinetics of B-16 melanoma cell population**

Kinetics of B-16 melanoma cell population was studied at determination of melanocytes and DNA-synthesizing cells percentage in total studied tumor cells.

For this purpose tumors of exponential growth phase were used. On 7-th day after subcutaneous inoculation experimental С57BL/6 mice (body weight of 17-20 g; tumor size

Binary Radiotherapy of Melanoma - Russian Research Results 131

In our studies we have used the following medicines: [10B]-ВРА (Khoknlov, 2001, Kulakov, 2001, Kulakov, 2002) – 4-(dihidroxyboron)–L-phenilalane (BPA, KatChem, Chehia), Katchem, (Czechia), chemical purity of 98 % , degree of enrichment of 10В 99.7 %); borated ethers with

(Czechia) , chemical purity of 99 % ; degree of enrichment of 10В – 99.7 %; novel boroncontained compound KUG-1 (this is manufacturing code of compound), chemical purity of 99 % with natural boron and Dipentast® – Gd-DTPA based pharmaceutical with Gd content of

The dogs were intravenously administrated with boron-containing compounds while the mice were administrated with boron-containing compounds intraperitoneally. Dipentast® was administrated intratumorally at uniform distribution (4-6 injection per tumor) both in

In the time interval from 1 to 12 h after the BSH administration relatively high boron content was in subcellular structures of tumor tissue. BSH was preferably accumulated in nuclei and mitochondria. (Table 1). These data suggest the BNCT with BSH might be more effective

Nucleus 5.7 14 6.9 12.0 2.2 2.9 Mitochondria 3.0 6.1 2.6 5.1 2.1 0.5 Lysosomes 0.8 1.8 - 4.9 2.0 1.2 Cytosol 1.5 1.2 0.2 1.5 0.2 1.3 Table 1. 10В concentration in subcellular fractions of B-16 melanoma and liver in С57Bl/6

In the time interval from 24 to 48 h after the KUG-1 administration maximal boron content was in nuclear fraction. This concentration exceeded necessary and sufficient concentration for successful NCT. Boron content in other subcellular fractions was sufficient for therapeutic efficacy of NCT. (Table 2). Therefore boron subcellular distribution had

Nucleus 8.13 9.1 10.9 9.3 Mitochondria 4.59 3.17 4.29 4.56 Lysosomes 3.48 3.83 4.58 13.5 Cytosol 3.3 5.28 1.53 5.8 Table 2. 10В concentration in subcellular fractions of B-16 melanoma and liver in С57Bl/6

Time after administration, h 1 6 12 Tumor Liver Tumor Liver Tumor Liver

> Time after administration, h 24 48 Tumor Liver Tumor Liver

10B12H11SH - [10B]-BSH (Katchem,

D-fructose ([10B]-ВРА-F) and D-galactose ([10B]-ВРА-Gal); Na2

during time interval from 6 to 12 h after drug administration.

28.11% and semi-elimination period from site of injection - 556 min.).

**2.10 Drugs** 

NCT and PCT studies.

Subcellular fractions

**3. Results of investigations** 

mice after BSH administration [10В µg/g]

confirmed clinical perspectives of KUG-1.

mice after KUG-1 administration [10В µg/g]

Subcellular fractions

**3.1 Cell pharmacokinetics** 

of 4-5 mm in diameter) were intraperitoneally administrated with 100 mg of BSH per 1 kg of body weight. In 1 hour before euthanasia the mice were administrated with 3Н-thymidin (74 kBq/g of body weigh); as control administration saline was used Excised tumors were used for preparation of cytological preparations. Melanocytes were determined as cells containing more than 5 granules of melanin (Alberts, 1989). Analysis of kinetics of DNAsynthesizing cells was studied in preparations covered with "M" emulsion counting 3Нlabelled melanocytes. These parameters were separately assessed for peripheral and central zones.
