Benefits of hypericin transport and delivery by low- and high-density lipoproteins to cancer cells: From in vitro to ex ovo.

Lipoproteins are very attractive natural-based transport systems suitable for applications in diagnostics and cancer therapy. Low- and high-density lipoproteins (LDL, HDL) were selected for hypericin (hyp) delivery in cancer cells. Hyp was used, as it is a well-known model for hydrophobic molecules, in order to estimate the LDL and HDL transport efficacy. We applied fluorescence techniques, absorption and Raman spectroscopy to characterize the state and alteration of LDL and HDL in the absence and presence of hyp. The fluorescence intensity of hyp loaded in lipoproteins was two times weaker in HDL than LDL. We demonstrated that there are faster redistribution kinetics of hyp from HDL than from LDL. As a consequence, hyp uptake by glioma and breast cancer cells was driven more via endocytosis when hyp was delivered by LDL than by HDL. Hyp induced photodynamic action was stronger when hyp was delivered by HDL than LDL. Ex ovo hyp fluorescence pharmacokinetics demonstrated differences in biodistributions of hyp in lipoproteins topical applications. However, hyp was successfully delivered to cancer cells grafted on quail's chorioallantoic membrane. The results presented in this paper could provide strategies to develop adequate and targeted anticancer therapy.

Hypericin can cross barriers in the chicken's chorioallantoic membrane model when delivered in low-density lipoproteins.

BACKGROUND: Low-density lipoproteins (LDL) were used as a natural drug delivery system for the transport of hypericin (Hyp) in the bloodstream of the chicken's chorioallantoic membrane model (CAM). Hyp was chosen as a model for hydrophobic drug used in photo-diagnosis and photo-treatments (PDT). The extravasation of the Hyp:LDL complexes for different concentration ratios and the redistribution of Hyp between different serum components were investigated with an innovative statistical treatment. METHODS: Hyp biodistribution was monitored in CAM by intravital fluorescence microscopy. The innovative statistical treatment of experimental data presented here enabled us to obtain highly detailed information from the weak Hyp fluorescence distribution in CAM blood vessels. Hyp redistribution between the serum components was studied by fluorescence spectroscopy in lipids/protein composed solutions. RESULTS: Extravasation of Hyp was dependent on Hyp:LDL concentration ratio. While Hyp:LDL = 50:1 resulted in a significant Hyp extravasation, the Hyp extravasation from Hyp:LDL = 100:1 was weak. The redistribution of Hyp was found to be faster for lipidic particles than for proteins. CONCLUSION: We have demonstrated that lipids composition has a significant control over Hyp delivery in CAM.

Response of Heme Symmetry to the Redox State of Bovine Cytochrome c Oxidase.

Second-derivative absorption spectroscopy was employed to monitor the response of effective symmetry of cytochromes a and a3 to the redox and ligation states of bovine cytochrome c oxidase (CcO). The Soret band π → π* electronic transitions were used to display the changes in symmetry of these chromophores induced by the reduction of CcO inhibited by the exogenous ligands and during catalytic turnover. The second derivative of the difference absorption spectra revealed only a single Soret band for the oxidized cytochromes a and a3 and cyanide-ligated oxidized cytochrome a3. In contrast, two absorption bands were resolved in ferrous cytochrome a and ferrous cytochrome a3 ligated with cyanide. A transition from one-band spectrum to two-band spectrum indicates the lowering of symmetry of these hemes due to the alteration of their immediate surroundings. It is suggested that the changes in polarity occurring in the vicinity of these cofactors are main reason for the split of the Soret band of both ferrous cytochrome a and cyanide-bound ferrous cytochrome a3.

Relationship between A163G osteoprotegerin gene polymorphism and other osteoporosis parameters in Roma and non-Roma postmenopausal women in eastern Slovakia.

BACKGROUND: The study was focused on evaluating the possible correlation between biochemical, anthropometric, and genetic indicators of osteoporosis in postmenopausal women. The frequency of genotypes and differences in measured parameters were evaluated within two ethnically different groups of women in Slovakia. METHODS: The study included 310 postmenopausal women divided into non-Roma and Roma groups. Based on results of densitometry, they were divided into control groups and women with osteoporosis and osteopenia. In all women, a genetic analysis of polymorphism of osteoprotegerin gene promotor region (A163G) was provided along with measurement of indicators of bone tissue metabolism. RESULTS: There is a particularly low incidence of osteoporosis in Roma women. We found a correlation between bone mineral density (BMD), body mass index, and waist and hip circumference in women with osteoporosis and in Roma women with osteopenia. The frequency of the AG genotype was higher in non-Roma women with osteoporosis, but reached only 10.7% in Roma women with osteopenia. While the presence of the G allele in the non-Roma population was accompanied by higher BMD and markers of osteoformation, it was accompanied by significantly higher concentrations of parathyroid hormone in the Roma population. CONCLUSION: The presence of the AG genotype has a different effect on bone metabolism in two ethnically diverse populations of women in Slovakia. In the general population, the presence of the G allele exhibited protective effects consistent with other studies, but in Roma population this appears to be the allele A. However, this requires a further study for confirmation and more detailed characterization of the differences between populations that have this work indicated.

Detection and aggregation of the antitumoral drug parietin in ethanol/water mixture and on plasmonic metal nanoparticles studied by surface-enhanced optical spectroscopy: Effect of pH and ethanol concentration.

In the present paper, we have investigated the effect of ethanol in aqueous media, the pH and the presence of Ag nanoparticles (NPs) on the aggregation processes of the antitumoral anthraquinone parietin in aqueous media and on the metal surface. UV-visible absorption, fluorescence and Raman spectra of parietin were used for such purpose. The present study provides information about the deprotonation and molecular aggregation processes occurring in parietin under different environments: ethanol/water mixture and when adsorbed onto Ag nanoparticles. The effect of ethanol on the optical properties of parietin in alcohol-water mixtures was also investigated at different ethanol concentrations with the time. For the case of the adsorption and organization of parietin molecules on the surface of Ag NPs, special attention was paid to the use of surface-enhanced optical techniques, SEF (surface-enhanced fluorescence) and SERS (surface-enhanced Raman scattering), for the characterization of the parietin aggregates and the ionization of the molecule on the surface. In particular, we have studied the variation of the SEF signal with the pH, which depends on the molecular organization of the molecule on the surface. Furthermore, a detailed analysis of the SERS spectra at different pH was accomplished and the main Raman bands of the protonated, mono-deprotonated and di-deprotonated parietin were identified. Finally, the second ionization pK of parietin on metal NPs was deduced from the SERS spectra.