[Chlorine e6 in phospholipid nanoparticles with specific targeting and penetrating peptides as prospective composition for photodynamic therapy of malignant neoplasms]. / Khlorin e6 v fosfolipidnykh nanochastitsakh so spetsificheskimi adresnymi i pronikaiushchimi peptidami kak perspektivnaia kompozitsiia dlia fotodinamicheskoi terapii zlokachestvennykh novoobrazovanii.

Cytotoxic and photoinduced activity of chlorine e6 (Ce6) in phospholipid nanoparticles with specific tumor targeting and cell-penetrating peptides was studied in vitro using human fibrosarcoma cells HT-1080. It was shown, that the binding of cell-penetrating peptide R7 - alone or combined with the peptide containing specific targeting motif NGR (Asn-Gly-Arg) - resulted in 3-fold decrease of Ce6 photoinduced activity as compared with that in nanoparticles without peptides (IC50 values were 0.7 µg/ml and 2.1 µg/ml, respectively). The NGR influence was unexpectedly low - less than 20% (IC50 1.7 µg/ml). This suggests the more importance of Ce6 cell penetration in this case, than of NGR-mediated targeting. The effect of inclusion of both peptides on the total cytotoxicity of Ce6 was minimal (10-16 times less than on the specific photoinduced activity). The obtained results - together with earlier shown effects on improvement of the pharmacokinetics of Ce6 in vivo after its embedding into phospholipid nanoparticles - indicate the prospects of using the obtained phospholipid nanoparticles system for photodynamic therapy.

[Increase of antituberculosis efficiency of rifampicin embedded into phospholipid nanoparticles with sodium oleate]. / Povyshenie protivotuberkuleznogo deistviia rifampitsina pri vstraivanii v fosfolipidnye nanochastitsy c oleatom natriia.

The formulation of the antituberculosis drug rifampicin embedded into 20-30 nm nanoparticles from soy phosphatidylcholine and sodium oleate, is characterized by greater bioavailability as compared with free drug substance. In this study higher antituberculosis activity of this formulation was shown. Rifampicin in nanoparticles demonstrated more effective inhibition of M. tuberculosis H37Rv growth: minimal inhibiting concentration (MIC) was twice smaller than for free rifampicin. Administration of this preparation to mice with tuberculosis induced by M. tuberculosis Erdman revealed that after 6 weeks of oral administration the CUF value in lung was 22 times smaller for rifampicin in nanoparticles than for free drug (1.7 un. vs. 37.4 un.). The LD50 value in mice was two fold higher for rifampicin in nanoformulation.

[Influence of doxorubicin inclusion into phospholipid nanoparticles on tumor accumulation and specific activity]. / Vliianie vkliucheniia doksorubitsina v fosfolipidnye nanochastitsy na nakoplenie v opukholi i spetsificheskuiu aktivnost'.

The specific activity of drug formulation of doxorubicin embedded into phospholipid nanoparticles with diameter less than 30 nm ("Doxolip") was studied in mice LLC carcinoma. Doxolip was prepared according to technology that was elaborated in Institute earlier. Doxorubicin tumor accumulation after intraperitoneal administration (at 4 h) was 4.5 times higher for Doxolip, than for free doxorubicin. The study of doxorubicin antitumor activity in developing tumor after single intravenous administration, 48 h after inoculation, showed, that: 1) tumor growth inhibition of Doxolip was observed at 6th day, while it was only at 11th day for free doxorubicin and revealed in less extent; 2) there was no antitumor effect of free doxorubicin at 8 days after administration of doses 2 and 4 mg/kg, but it was observed for Doxolip in dose-dependent manner, 10% and 30% correspondently. In experiment with developed tumor weekly Doxolip intraperitoneal administration (5 mg/kg, 3 weeks beginning from 7 days after inoculation) resulted in 56% decrease of tumor volume as compared with control. This parameter for free doxorubicin was 2.8 times lower. The obtained data indicate, that incorporation of doxorubicin into phospholipid nanoparticles with size up to 30 nm as delivery system increases its tumor accumulation and results to increase of specific activity both in intraperitoneal and in intravenous administration.

New peptidomimetics of insulin.

New peptidomimetics that have been obtained in the course of our experimental work show distinct insulin-like activity both in vitro and in vivo. The first peptidomimetic (PM 1) is essentially a decapeptide in which sites of A (20-21) and B (19-26) chains of insulin are linked by the peptides bond (Cys-Gly-Glu-Arg-Gly-Phe-Phe-Tyr-Cys-Asn). The second peptidomimetic (PM 2) has similar set of amino acid residues, except that two aromatic amino acids corresponding to the residues of B chain of insulin (B24 and B26) have been replaced with their D optical isomers (Cys-Gly-Glu-Arg-Gly-DPhe-Phe-DTyr-Cys-Asn). The third peptidomimetic (PM 3) has been obtained through acylation of N-terminal of PM 1 by the use of palmitic acid. The peptidomimetic incorporating D aromatic amino acids (PM 2) was demonstrated to exhibit more pronounced hypoglycemic impact, while the acylation of decapeptide tends to prolong the effective time of peptidomimetic influence in vivo.

Synthetic insulin fragment with insulin-like biological activity.

An insulin fragment, representing the C-terminal functionally important site of its molecule and responsible for receptor binding, was synthesized. The fragment consists of two peptides: a dipeptide (A 20-21) and an octapeptide (B 19-26), linked with a disulfide bond (A20-B19). The biological activity of the newly synthesized fragment relative to insulin was assayed for the influence on glycogenesis and for the ability to stimulate glucose uptake. Comparative tests for the biological activity of the synthesized fragment and of the intact hormone allowed us to conclude that the fragment has insulin-like properties.