Methacrylate Ester Monomers.

The Expert Panel for Cosmetic Ingredient Safety reviewed newly available studies since their original assessment in 2005, along with updated information regarding product types and concentrations of use, and confirmed that these 22 methacrylate ester monomers are safe as used in nail enhancement products in the practices of use and concentration as described in this report, when skin contact is avoided.

Thermo- and Light-Responsive Polymer-Coated Magnetic Nanoparticles as Potential Drug Carriers.

A series of thermo- and light-responsive copolymers of poly (N-isopropylacrylamide) (PNIPAM) and 6-[4-(4-methoxy phenyl azo)-phenoxyl-hexyl methacrylate) (AzoMA) (PNIPAM-b-PAzoMA) were synthesized via reversible addition-fragmentation chain transfer (RAFT) radical polymerization. The resulting copolymers had a narrow molecular weight distribution range of 1.06-1.24, in which M n changed regularly with the monomer concentration. Subsequently, the diblock copolymers were successfully modified on the surface of iron oxide nanoparticles through the interaction between the chemical bonds to prepare Fe3O4@(PNIPAM-b-PAzoMA) nanoparticles. The size of fabricated nanoparticles with excellent thermo-sensitivity and photo-sensitivity was controlled at about 40-50 nm. Cell viability assays suggested that the nanoparticles showed no significant cytotoxicity and potential drug delivery in the tumor microenvironment.

Fabrication and evaluation of an organic monolithic column based upon the polymerisation of hexyl methacrylate with 1,6-hexanediol ethoxylate diacrylate for the separation of small molecules by capillary liquid chromatography.

This paper describes the fabrication of a new porous monolith, prepared in 100µm i.d. capillaries by the co-polymerisation of hexyl methacrylate with 1,6-hexanediol ethoxylate diacrylate, poly (HMA-co-1,6 HEDA), in the presence of azobisisobutyronitrile, 1, 4-butanediol and 1-propanol were used as porogens for the monoliths; the monoliths were then used as a stationary phase for capillary liquid chromatography. Two cross linkers namely 1,6 HEDA and EDMA were utilised in order to investigate the effects of cross linker length on the separation efficiency of small molecules, and it was found that the efficiency of the separation improved tenfold when using the longer cross linker, 1,6 HEDA. This improvement is associated with the increase in number of methylene groups which resulted in an increased number of mesopores, less than 50nm. The 1,6 HEDA based monolith showed a high porosity (90%) and no evidence of swelling or shrinking with the use of organic solvents. Moreover, the 1,6 HEDA monolith demonstrated high reproducibility for the separation of the retained compounds anisole and naphthalene; these showed retention time RSDs of 1.79% and 2.74% respectively. The fabricated monolith also demonstrated high selectivity for neutral non-polar molecules, weak acids, and basic molecules. The asymmetry factors for basic molecules (nortriptyline and amitriptyline) were 1.5 and 1.3 respectively, indicating slight tailing, which is often noticeable on silica based phases due to secondary interactions between basic moieties and the hydroxyl groups of the silica.