Bioactive Coatings Formed on Titanium by Plasma Electrolytic Oxidation: Composition and Properties.

Bioactive coatings on VT1-0 commercially pure titanium were formed by the plasma electrolytic oxidation (PEO). A study of the morphological features of coatings was carried out using scanning electron microscopy. A composition of formed coatings was investigated using energy-dispersive spectroscopy and X-ray diffractometry analysis. It was shown that PEO-coatings have calcium phosphate in their composition, which increases the bioactivity of the surface layer. Electrochemical properties of the samples were studied by potentiondynamic polarization and electrochemical impedance spectroscopy in different physiological media: simulated body fluid and minimum essential medium. The data of electrochemical studies indicate more than 15 times decrease in the corrosion current density for the sample with coating (5.0 × 10-9 A/cm2) as compared to the bare titanium (7.7 × 10-8 A/cm2). The formed PEO-layers have elastoplastic properties close to human bone (12-30 GPa) and a lower friction coefficient in comparison with bare metal. The wettability of PEO-layers increased. The contact angle for formed coatings reduced by more than 60° in comparison with bare metal (from 73° for titanium to 8° for PEO-coating). Such an increase in surface hydrophilicity contributes to the greater biocompatibility of the formed coating in comparison with commercially pure titanium. PEO can be prospective as a method for improving titanium surface bioactivity.

Alkaloids of fascaplysin are promising chemotherapeutic agents for the treatment of glioblastoma: Review.

Glioblastoma is one of the most aggressive human brain tumors. Even following all the modern protocols of complex treatment, the median patient survival typically does not exceed 15 months. This review analyzes the main reasons for glioblastoma resistance to therapy, as well as attempts at categorizing the main approaches to increasing chemotherapy efficiency. Special emphasis is placed on the specific group of compounds, known as marine alkaloids and their synthetic derivatives exerting a general antitumor effect on glioblastoma cells. The unique mechanisms of marine alkaloid influence on the tumor cells prompt considering them as a promising basis for creating new chemotherapeutic agents for glioblastoma treatment.

3-Bromofascaplysin is a prospective chemical compound for developing new chemotherapy agents in glioblastoma treatment.

Glioblastoma (GB) is one of the most aggressive human brain tumors. The prognosis is unfavorable, its treatment is relatively ineffective, and the median survival is about 15months. Medication development with new chemical compounds is one of the ways to solve the problem of current treatment inefficiency. This study is focused on the group of chemical substances, based on pentacyclic system of 12H-pyrido[1,2-a:3,4-b]diindole, and the most well-known part of this group is fascaplysin, first extracted from the sponge Fascaplysinopsis spp. We have synthesized a series of the following fascaplysin derivatives: 7-phenylfascaplysin, 3-chlorofascaplysin, 3-bromofascaplysin, 9-bromofascaplysin. The paper is aimed at analyzing the cytotoxic effect of these compounds on GB cells. MATERIALS AND METHODS: The study used rat glioma C6 cell line (ATCC®; cat no CCL-107), U-87MG cell line (ATCC; cat no. HTB-14™) and human glioblastoma T98-G cells (ATCC® CRL-1690™). Cell culture method, experimental pharmacological trials and γ-radiation in vitro, as well as flow cytofluorometry were used in the study. RESULTS: Cytotoxic effect of the tested compounds is stronger than the effect of unsubstituted fascaplysin, and appears to be dose-dependent and time-dependent. 3-bromofascaplysin is more efficient for cancer cells elimination, and by the end of the experiment the amount of living cancer cells in G0 phase remained at its lowest. Cytotoxic effect of 3-bromofascaplysin on glioblastoma T98-G cells is inferior to that of TMZ, and in case of preliminary radiation treatment of cancer cells with 48Gy the effect of the compound matches the TMZ treatment results. CONCLUSION: 3-Bromofascaplysin is a prospective chemical compound for development of new anti-cancer chemotherapeutic agents.