Polymer microspheres as a scaffold for nitric oxide release in PBS buffer and bovine serum
作者：Tuanwei Liu, Dongwei Zhang, Xinlin Yang*, and Chenxi Li
关键字：Nitric oxide; N-diazeniumdiolate polymer microsphere; NO release nanoparticles.
论文来源：期刊
具体来源：Polymer Chemistry 6 (9), 1512-1520 (2015). DOI: 10.1039/C4PY01326C
发表时间：2015年
This paper reports the design, preparation and
characterization of functional polymer microsphere as a reservoir for nitric
oxide (NO)-release. Silica/polymer core-shell microspheres and the
corresponding hollow functional polymer microspheres with secondary amino
groups were converted to N-diazeniumdiolate
as scaffolds for nitrogen oxide (NO) release. The silica/polymer core-shell
microspheres were prepared by a multi-step procedure, which involves synthesis
of functional 2-(ethyl(boc)amino)ethyl methacrylate (bocAmEMA) monomers with
boc-protected secondary amine sites, distillation precipitation polymerization
of ethyleneglycol dimethacrylate and boc-protected co-monomers with presence of
3-(methacryloxy)propyltrimethoxysilane (MPS)-modified silica nanoparticles as
seeds, de-protection of the amino sites, and subsequent reaction between the
secondary amino and NO under high pressure (5.0 atm) in presence of sodium
methoxide. The corresponding hollow polymer microspheres are prepared via the selective
removal of silica core from silica/polymer core-shell microspheres with
hydrofluoride (HF) aqueous solution and the subsequent conversion to N-diazeniumdiolate NO donors via
exposure to high pressure of NO (5.0 atm) under basic condition. The hollow
microspheres with secondary amino groups exhibited a high storage capacity for
NO (up to 5.5 mmol NO/mg), greatly increasing that of
NO from the corresponding silica/polymer core-shell donors (3.6 mmol NO/mg). Both the silica/polymer and
hollow polymer scaffolds are shown to release NO for extended periods of time
with an ‘apparent’ t1/2 value of 35 min (silica/polymer scaffolds; PBS buffer), 10 min (hollow polymer
scaffolds; PBS buffer), 19 min (hollow polymer scaffolds; bovine
serum), and release durations of 15 h via the proton initiated
diazeniumdiolate decomposition to give off NO spontaneously under physiological
conditions.