EpCAM aptamer-functionalized mesoporous silica nanoparticles for efficient colon cancer cell-targeted drug delivery.

Targeted delivery of anticancer agents by functional nanoparticles is an attractive strategy to increase their therapeutic efficacy while reducing toxicity. In this work, doxorubicin (DOX)-loaded mesoporous silica nanoparticles (MSNs) were modified with aptamer (Ap) against the epithelial cell adhesion molecule (EpCAM) for targeted delivery of DOX to colon cancer cells. These nanoparticles (Ap-MSN-DOX) were characterized by particle size, zeta potential, aptamer conjugation efficiency, drug encapsulation efficiency, and drug release properties. The in vitro cell recognition, cellular uptake, EpCAM protein inhibition efficiency, and cytotoxicity of Ap-MSN-DOX were also studied. Results demonstrated that EpCAM conjugation increased binding of Ap-MSN-DOX to EpCAM over-expressing SW620 colon cancer cells but not EpCAM-negative Ramos cells, resulting in enhanced cellular uptake and increased cytotoxicity of the DOX in SW620 cells when compared to non-Ap-modified nanoparticles (MSN-DOX). Additionally, Ap-MSN-DOX exhibited significant inhibition effects on the expression of EpCAM on SW620 cells. These results suggested that Ap-MSN-DOX has the potential for the targeted delivery of therapeutic agents into EpCAM positive colon cancer cells to improve therapeutic index while reducing side effects.

Xie X ，Li F ，Zhang H ，Lu Y ，Lian S ，Lin H ，Gao Y ，Jia L ... -  《-》

Epithelial cell adhesion molecule aptamer conjugated PEG-PLGA nanopolymersomes for targeted delivery of doxorubicin to human breast adenocarcinoma cell line in vitro.

Targeted delivery of anti-cancer agents exclusively to tumor cells introduces an attractive strategy because it increases the therapeutic index compared with untargeted drugs. Aptamer conjugated nanoparticles that can specifically bind to the proteins on a tumor cell surface are capable nanoscale delivery systems for enhancing cellular uptake of chemotherapeutic agents. The epithelial cell adhesion molecule (EpCAM) as a cancer stem cell marker emerges as a versatile target for aptamer-based cancer therapy due to its high expression level in various adenocarcinoma cell lines and its very low expression level in normal cells. We developed EpCAM-targeted PEG-PLGA nanopolymersomes by covalently coupling the EpCAM aptamer to the surface of nanopolymersomes loaded with the anticancer agent doxorubicin via pH gradient method. The results indicated that doxorubicin was entrapped in PEG-PLGA nanopolymersomes with encapsulation efficiency and loading content of 91.25±4.27% and 7.3±0.34%, respectively. Over a period of 5 days, up to 8% of the DOX was released through this system. The doxorubicin-loaded aptamer conjugated nanopolymersomes exhibited efficient cell uptake and internalization, and were significantly more cytotoxic (P<0.01) toward EpCAM-positive tumor cells (MCF-7) than non-targeted nanopolymersomes. Our data suggest that EpCAM-targeted nanopolymersomes will lead to an improved therapeutic index of doxorubicin to EpCAM positive cancer cells.

Alibolandi M ，Ramezani M ，Sadeghi F ，Abnous K ，Hadizadeh F ... -  《-》

Hybrid silica-coated Gd-Zn-Cu-In-S/ZnS bimodal quantum dots as an epithelial cell adhesion molecule targeted drug delivery and imaging system.

Dual-modal imaging probes based on fluorescence (FL) and magnetic resonance (MR) modalities have attracted great attention due to their ability to combine the target specificity and high penetration into body tissues. In this study, we developed a potent nanocarrier with an effective photoluminescent emission and MR imaging capacity to deliver the doxorubicin to breast cancer 4T1 cells. The nanocarrier was fabricated by coating of quantum dots (QDs) with mesoporous silica followed by amine functionalization of the silica surface. Then, the doxorubicin was loaded into the silica pores and biheterofunctional PEG was covalently bound to the surface of core-shell quantum dot mesoporous silica nanoparticles. In order to target the DOX-loaded nanoparticles, the EpCAM DNA aptamer was attached on the surface of the DOX-loaded PEGylated nanoparticles. The synthesized NPs were analyzed for their size distribution, morphology, zeta potential and magnetic susceptibility using HRTEM, SEM and VSM analysis. The QD-encapsulated mesoporous silica revealed spherical shapes with an average particle size of 100 nm. The maximum encapsulation efficacy of doxorubicin in the silica pores was 25%. The in vitro release assessment demonstrated the pH-sensitive release of doxorubicin from the designed formulations. The in vitro cytotoxicity assays indicated that the aptamer targeted nanoparticles showed greater cytotoxicity than both non-targeted NPs and free DOX toward 4T1 and MCF-7 cell lines. The in vivo studies in 4T1 tumor-bearing Balb/c mice demonstrated that EpCAM aptamer could specifically deliver the DOX-loaded nanoparticles into the tumor tissue and cause remarkable inhibition of tumor growth as compared to non-targeted formulation and free DOX. Moreover, the in vivo MR and fluorescent imaging in 4T1 tumor-bearing mice confirmed the accumulation and residence of targeted system in tumor tissue even 24 h post-injection. This work presents a novel system for preparing bimodal imaging theranostic NPs through hybridization of silica and magnetic-fluorescent quantum dots.

Akbarzadeh M ，Babaei M ，Abnous K ，Taghdisi SM ，Peivandi MT ，Ramezani M ，Alibolandi M ... -  《-》

Natural gelatin capped mesoporous silica nanoparticles for intracellular acid-triggered drug delivery.

Zou Z ，He D ，He X ，Wang K ，Yang X ，Qing Z ，Zhou Q ... -  《-》

A dual-functional HER2 aptamer-conjugated, pH-activated mesoporous silica nanocarrier-based drug delivery system provides in vitro synergistic cytotoxicity in HER2-positive breast cancer cells.

Shen Y ，Li M ，Liu T ，Liu J ，Xie Y ，Zhang J ，Xu S ，Liu H ... -  《International Journal of Nanomedicine》