Smart silica-based nanoparticles for targeted drug delivery

Amongst various nanocarriers used for drug delivery applications, silica nanoparticles have received emerging interest. Also they have gained FDA investigational new drug approval for their human use in clinical trial. Mesoporous silica nanoparticles (MSN) are used extensively as drug delivery vehicles due to their excellent properties such as tunable nanoparticle size, large pore volume, highly ordered channels, convenient surface functionalization and large surface area.We synthesized various types of silica NPs in our laboratory comprising MSN, hollow mesoporous silica nanoparticles (HMSNs), rod silica NPs and dendritic silica NPs.Our research provides and important avenue for development of hybrid silica-based nanomedicines.In one of our study, to efficiently deliver the chemotherapeutics to the tumor tissue and minimize the associated adverse effects, nucleolin-targeted hybrid nanostructure based on HMSNs were fabricated. To provide the controlled, sustained drug release and enhance blood circulation, the surface of doxorubicin-encapsulated HMSNs were coated with acetylated carboxymethyl cellulose (Ac-CMC) and then covalently conjugated to AS1411 aptamer for guided drug delivery to nucleolin overexpressed cancerous cells. In vitro cellular uptake and cytotoxicity studies confirmed that AS1411 aptamer specifically targets nucleolin overexpressing MCF-7 and C26 cells. Moreover, the in vivo tumor inhibitory effect of AS1411 aptamer conjugated formulation demonstrated a superior therapeutic efficiency over non-targeted formulation and free doxorubicin. The obtained results might open a new insight to the development of targeted intelligent hybrid materials based on AcCMC-coated HMSNs with high loading capacity, smart characteristics and desirable anticancer potential.