One-Pot Synthesis of Phenylboronic Acid-Based Microgels for Tunable Gate of Glucose-Responsive Insulin Release at Physiological pH.

Glucose-responsive insulin delivery systems that effectively regulate insulin retention and release in response to real-time fluctuation of glucose levels are highly desirable for diabetes care with minimized risk of hypoglycemia. Herein, we report a class of glucose-sensitive copolymer microgels, prepared from a simple one-pot precipitation copolymerization of 4-vinylphenylboronic acid (VPBA), 2-(dimethylamino) ethyl acrylate (DMAEA), and oligo(ethylene glycol) methyl ether methacrylate (M = 300, MEOMA), for gated glucose-responsive insulin release within the physiologically desirable glucose level range. The composition of the p(VPBA-DMAEA-MEOMA) copolymer microgels were analyzed using NMR and FTIR spectra.

Catalytic degradation of various dyes using silver nanoparticles fabricated within chitosan based microgels.

Precipitation polymerization method was used to synthesize chitosan based poly[chitosan-N-isopropylmethacrylamide-acrylic acid] [P(CS-NI-AA)] microgel particles. Synthesized P(CS-NI-AA) microgel particles were utilized as micro-reactors for the fabrication of silver nanoparticles (AgNPs) inside the structure of microgels through chemical reduction of Ag ions using NaBH as reducing agent. P(CS-NI-AA) and Ag-P(CS-NI-AA) systems were analyzed using various characterization techniques like scanning electron microscopy (SEM), ultraviolet-visible (UV-visible) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy.

,-Dimethylaminoethyl methacrylate-based core/shell microgels loaded with silver nanoparticles for catalysis.

In this work, poly(styrene)@poly(-isopropylmethacrylamide--2-(,-dimethyl)aminoethyl methacrylate [p(sty)@p(NIPMAM-DMAEMA)] core/shell microgel particles were produced by a two-step free-radical precipitation polymerization process. Ag nanoparticles were successfully embedded inside the sieves of a crosslinked network by using silver nitrate as the precursor salt and NaBH as the reductant. The synthesized pure and hybrid microgels were analyzed by various characterization tools, including Fourier transform infrared (FTIR) and UV-visible (UV-vis) spectroscopies, transmission electron microscopy (TEM) and dynamic light scattering (DLS).

Fabrication of silver nanoparticles within chitosan based microgels for catalysis.

Chitosan based monodisperse poly[chitosan-N-isopropylmethacrylamide-acrylic acid] [P(CNA)] microgels were produced via precipitation polymerization. Resulting crosslinked P(CNA) micro particles were used as micro-reactors to prepare silver nanoparticles within the polymeric network by chemical reduction of Ag ions with sodium borohydride. Various techniques including transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-vis) spectroscopy were used to analyze P(CNA) microgels and Ag-P(CNA) hybrid microgels.

5,7,7,12,14,14-Hexamethyl-4,11-diaza-1,8-diazo-niacyclo-tetra-decane bis-(perchlorate) monohydrate.

In the title hydrated salt, C(16)H(38)N(4) (2+)·2ClO(4) (-)·H(2)O, the dication is protonated at the diagonally opposite N atoms proximate to the -C(CH(3))(2)- groups. Within the cavity, there are two ammonium-amine N-H⋯N hydrogen bonds. Supra-molecular layers are formed in the crystal packing whereby the water mol-ecule links two perchlorate anions, and the resultant aggregates are connected to the dications via N-H⋯O hydrogen bonds.