Poly(DMAEMA-co-MPS) coated mesoporous silica nanoparticles as smart drug carriers with pH-controlled on-off release

In this paper, pH-responsive nanocarriers based on mesoporous silica nanoparticles (MSN) modified with the pH-sensitive polymer: poly(AyV-dimethylaminoethyl methacrylate) (PDMAEMA) were constructed, characterized and tested to evaluate their efficacy as drug delivery systems (DDS). The hybrid nanocarriers were synthesized successfully via a simultaneous copolymerization reaction between two monomers; 2-dimethylamino-ethylmethacrylate (DMAEMA) and 3-methacryloxypropyltrimethoxysilane (MPS) within the mesopores of MSN. Exploiting the polymerizable moiety of MPS together with its alkoxysilane moity susceptible to condensation with silanols surface onto silica, MPS comono-mer can act as a bridge for yielding a robust and simple hybrid consisting of MSN-P(DMAEMA-co-MPS). In addition, the grafted PDMAEMA serves as efficient gatekeeper to adjust the encapsulation and in vitro release of cargos loaded inside the pores by altering pH values of the medium. These hybrid nanoparticles showed a high loading capacity with quick release in acidic pH, which exists mainly in the diseases environments e.g. inflammatory and cancerous sites.