Cytotoxicity evaluation of extracts and fractions of five marine sponges from the Persian Gulf and HPLC fingerprint analysis of cytotoxic extracts

Objective: To screen the cytotoxic effects of some marine sponges extracts on HeLa and PC12 cells. Methods: Five marine sponges including Ircinia echinata (I. echinata), Dysidea avara, Axinella sinoxea, Haliclona tubifera and Haliclona violacea were collected from the Persian Gulf (Hengam Island). The cytotoxic effect of these sponges was evaluated by using MTT assay. The metabolic high performance liquid chromatography fingerprint of I. echinata was also carried out at two wavelengths (254 and 280 nm). Results: Among the sponges tested in this study, the extracts of I. echinata and Dysidea avara possessed the cytotoxic effect on HeLa and PC12 cells. The obtained fractions from high performance liquid chromatography were evaluated for their cytotoxic properties against the cell lines. The isolated fractions did not show significant cytotoxic properties. Conclusions: I. echinata could be considered as a potential extract for chemotherapy. Further investigation is needed to determine the accuracy of mechanism

Volumetric properties and sorption behavior of perfluoropolymers with dioxolane pendant rings

Lattice fluid theory is used to develop transport property–structure correlations for glassy perfluoropolymers with dioxolane pendant rings, a new class of membrane materials for gas separation. Poly(perfluoro-2-methylene-1,3-dioxolane) (poly(PFMD)) and poly(perfluoro-2-methylene-4-methyl-1,3-dioxolane) (poly(PFMMD)) exhibit lower permeability but much higher selectivity than commercial fluoropolymers, such as Teflons AF. Their enhanced separation performance is due to the combined effect of solubility- and diffusivity-selectivity. Moreover, poly(PFMD) and poly(PFMMD) exhibit enhanced CO2-philicity as compared to Teflons AF, which can be ascribed to the higher oxygen/carbon ratio exhibited by the former materials. To provide rational guidelines to maximize the solubility-selectivity, the enthalpic and entropic contributions to sorption coefficient were calculated and compared for several polymers of practical interest for gas separation. In the absence of localized penetrant–polymer interactions, gas sorption is controlled essentially by the free volume and solubility-selectivity is controlled by the polymer cohesive energy density

Dioxolane-Based Perfluoropolymers with Superior Membrane Gas Separation Properties

Glassy perfluoropolymers have become an exciting materials platform for membrane gas separation as they define the upper bounds for some gas separations, such as He/H₂, He/CH₄, and N₂/CH₄. However, due to the difficulty in synthesis, only a few glassy perfluoropolymers are commercially available, including Teflon AF and Hyflon AD derived from dioxoles and Cytop derived from dihydrofuran. In this study, two perfluoropolymers based on dioxolanes, poly­(perfluoro-2-methylene-1,3-dioxolane) (poly­(PFMD)) and poly­(perfluoro-2-methylene-4-methyl-1,3-dioxolane) (poly­(PFMMD)), were synthesized by radical polymerization and characterized thoroughly for physical properties such as glass transition temperature (<i>T</i>_g), <i>d</i>-spacing between polymer chains, and fractional free volume (FFV). The gas permeability and solubility were determined at 35 <i>°</i>C for a series of pure gases in these perfluorodioxolanes and compared with the commercial perfluoropolymers. Poly­(PFMD) and poly­(PFMMD) exhibit separation properties of He/H₂, He/CH₄, H₂/CH₄, H₂/CO₂, and N₂/CH₄ near or above the upper bounds in Robeson’s plots, and superior to the commercial perfluoropolymers, despite their similar <i>T</i>_g and FFV. The underlying reasons for the superior gas separation properties in these dioxolane-based perfluoropolymers are discussed

Comparison between Alpha and Calendula for Healing of Third-Degree Burn in Rats: Burn healing in rat by Alpha and Calendula

In this study, we compared the effects of Calendula and Alpha ointment in the treatment of burn wounds and also compared its results with silver sulfadiazine (SSD). Seventy-five male Sprague-Dawley rats were divided into five groups, and similar burn ulcers were produced on anterior surface of thigh of rats. In the first group of rats no treatment was applied, base gel was applied topically to group II, in groups III-V, Alpha, SSD, and Calendula preparations were applied, respectively. Wound healing, contraction, and histopathological evaluation were evaluated at the end of 7, 14, and 21 days. Alpha ointment was equally effective as Calendula gel, and had better efficacy compared to SSD for all markers of wound healing at days of 7, 14, and 21.Alpha and Calendula preparations are less expensive drugs and significantly improve the quality of wound healing and scar formation and are more appropriate treatment choices than SSD. Therefore, we recommended them as alternative to SSD, especially in patients with low economical backgrounds or in those who show adverse reactions to SSD