Publication Type Journal Article
Title Hybrid Mesoporous Nanoparticles for pH-Actuated Controlled Release
Authors José L. M. Gonçalves C. I. C. Crucho Sérgio Alves Carlos Baleizão José Paulo Farinha
Groups MPPM
Journal NANOMATERIALS
Year 2019
Month March
Volume 9
Number 3
Pages
Abstract Among a variety of inorganic-based nanomaterials, mesoporous silica nanoparticles (MSNs) have several attractive features for application as a delivery system, due to their high surface areas, large pore volumes, uniform and tunable pore sizes, high mechanical stability, and a great diversity of surface functionalization options. We developed novel hybrid MSNs composed of a mesoporous silica nanostructure core and a pH-responsive polymer shell. The polymer shell was prepared by RAFT polymerization of 2-(diisopropylamino)ethyl methacrylate (pKa similar to 6.5), using a hybrid grafting approach. The hybrid nanoparticles have diameters of ca. 100 nm at pH < 6.5 and ca. 60 nm at pH > 6.5. An excellent control of cargo release is achieved by the combined effect of electrostatic interaction of the cargo with the charged silica and the extended cationic polymer chains at low pH, and the reduction of electrostatic attraction with a simultaneous collapse of the polymer chains to a globular conformation at higher pH. The system presents a very low (almost null) release rate at acidic pH values and a large release rate at basic pH, resulting from the squeezing-out effect of the coil-to-globule transition in the polymer shell.
DOI http://dx.doi.org/10.3390/nano9030483
ISBN
Publisher
Book Title
ISSN 2079-4991
EISSN
Conference Name
Bibtex ID ISI:000464453800002
Observations
Back to Publications List