Hollow Double-Layered Polymer Microspheres with pH and Thermo-Responsive Properties as Nitric Oxide-Releasing Reservoirs
作者：Tuanwei Liu, Wei Zhang, Tao Song, Xinlin Yang*, Chenxi Li
關鍵字：Doule-shell hollow microspheres; NO reservior; Controlled release; pH and thermo dual-responisve
論文來源：期刊
具體來源：Polym. Chem., 6 (17), 3305-3314 (2015). DOI: 10.1039/C5PY00001G
發表時間：2015年
Nitric
oxide-releasing hollow double-layered polymer microspheres (HDPMs) with both
pH- and thermo-responsive properties in aqueous media are designed and prepared
by a multi-step process. Silica/polymer (SiO2/P(bocAmEMA-co-EGDMA)) core-shell microspheres with boc-protected
secondary amino groups are synthesized by distillation precipitation copolymerization
of 2-(ethyl(boc)amino)ethyl methacrylate (bocAmEMA) functional monomer and
ethyleneglycol dimethacrylate (EGDMA) in presence of 3-(methacryloxy)
propyltrimethoxysilane (MPS) modified silica nanospheres as seeds. Hollow
double-shelled polymer microspheres with secondary amino groups are prepared by
distillation precipitation copolymerization of N-isopropylacrylamide (NIPAAm) with 2-(dimethylamino) ethyl
methacrylate (DMAEMA) and EGDMA in presence of SiO2/P(bocAmEMA-co-EGDMA) core-shell microspheres as
seeds to obtain SiO2/P(bocAmEMA-co-EGDMA)/P(EGDMA-co-DMAEMA-co-NIPAAm) tri-layer microspheres with subsequent removal of silica
core by hydrogen fluoride aqueous solution and deprotection of secondary amino
groups with CF3CO2H. Hollow polymer microspheres with N-diazenuimdiolated NO donors are
prepared by the reaction between secondary amino groups of hollow P(AmEMA-co-EGDMA)/P(EGDMA-co-DMAEMA-co-NIPAAm) microspheres
and high pressure of NO (5.0 atm) under basic condition (CH3ONa). The
resultant microspheres are systematically characterized by TEM, FT-IR, TGA,
elemental analysis and dynamic laser scattering (DLS). The final N-diazeniumdiolated hollow
double-shelled microspheres show a controlled NO release behavior dependent on
the pH and temperature in the environment.