Designing a green poly(ß-amino ester) for the delivery of nicotinamide drugs with biological activities and conducting a DFT investigation.

The environmentally friendly polymerization process was carried out using microwave irradiation without additional solvents or catalysts to produce poly(ß-amino ester) (PßAE) which served as a drug delivery system. PßAE was synthesized through Michael addition polymerization of 1,4-butane diol diacrylate and piperazine. Swelling and biodegradation studies were conducted in various solvents and phosphate-buffered saline (PBS, pH 7.4) at 37 °C to evaluate the properties of the polymeric gel. The PßAE matrix demonstrated solubility enhancement for hydrophobic antimicrobial and antitumor-active nicotinamide derivatives (TEINH, APTAT, and MOAPM), controlling their release over 10 days in (PBS). The successful formation of free and loaded PßAE with nicotinamide active materials was confirmed by spectroscopic analysis including Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Optimization and physical descriptor determination via the DFT/B3LYP-631(G) basis set were performed to aid in the biological evaluation of these compounds with elucidation of their physical and chemical interaction between poly(ß-amino ester) and nicotinamide drugs.

Synthesis and characterization of nanosilver-silicone hydrogel composites for inhibition of bacteria growth.

PURPOSE: Nanosilver-silicone hydrogel (NAgSiH) composites for contact lenses were synthesized to asses the antimicrobial effects. METHODS: Silicone hydrogel (SiH) films were synthesized followed by impregnation in silver nitrate solutions (10, 20, 30, 40, 60, 80ppm) and in-situ chemical reduction of silver ions using sodium borohydride (NaBH4). The silver nano particles (AgNPS) were identified by UV-vis absorption spectroscopy, Energy-dispersive X-ray spectroscopy (EDX) mapping and EDX spectrum. Physico-mechanical and chemical properties of NAgSIH films were studied. The antimicrobial effect of the hydrogels against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus was evaluated. The numbers of viable bacterial cells on NAgSiH surface or in solution compared to control SiH were examined. RESULTS: The NAgSiH films were successfully synthesized. FTIR results indicated that AgNPS had no effect on the bulk structure of the prepared SiH films. From TGA analysis, NAgSiH(R80) and SiH(R0) films had the same maximum decomposition temperature (404°C). UV-vis absorption spectroscopy and EDX mapping and spectrum emphasized that AgNPS were in spherical shape. The maximum absorption wavelength of NAgSiH films were around 400nm. The light transmittance decreased as the concentration of AgNPS increased, but still greater than 90% at wavelength around 555nm. The Young's modulus increased gradually from 1.06MPa of SiH(R0) to highest value 1.38MPa of NAgSiH(R80). AgNPS incorporated into SiH films reduced the bacterial cell growth and prevented colonization. Groups NAgSiH(R60,R80) demonstrated an excellent reduction in bacterial viability in solution and on the SiH surface. CONCLUSIONS: NAgSiH composites were successfully synthesized and possessed an excellent antimicrobial effects.

Natural rubber base matrix containing Calendula officinalis plant as a source of molluscicdal saponin.

Natural rubber (NR) has been used as a binding matrix for Calendula officinalis, where it is used as a vulcanizate. Various doses of the plant covering the range from 100 up to 200 parts per 100 of rubber (phr) were found suitable for processing conditions using conventional rubber mixing equipment. The release rate of saponin was extended to over 4 months. Incorporation of fillers, such as HAF and Hisil, in the compounded rubber decreased the release of saponin; especially in the first period of immersion. The amount of saponin released was affected by the environmental temperature and the type of fillers present in the formulations. The scanning electron micrographs illustrate the presence of a tortuous pass and pore structure that formed after soaking in water and leaching process occurred.