Hierarchically targetable polysaccharide-coated solid lipid nanoparticles as an oral chemo/thermotherapy delivery system for local treatment of colon cancer.

Although oral formulations of anticancer chemotherapies are clinically available, the therapeutic action relies mostly on drug absorption, being inevitably accompanied with systemic side effects. It is thus desirable to develop oral therapy systems for the local treatment of colon cancers featured with highly selective delivery to cancer cells and minimized systemic drug absorption. The present study demonstrates the effective accumulation and cell uptake of the doxorubicin and superparamagnetic iron oxide nanoparticles-loaded solid lipid nanoparticle (SLN) delivery system for chemo/magnetothermal combination therapy at tumors by hierarchical targeting of folate (FA) and dextran coated on SLN surfaces in a sequential layer-by-layer manner. Both the in vitro and in vivo characterizations strongly confirmed that the dextran shells on SLN surfaces not only retarded the cellular transport of the FA-coated SLNs by the proton-coupled FA transporter on brush border membranes in small intestine, but also enhanced the particle residence in colon by specific association with dextranase. The enzymatic degradation and removal of dextran coating led to the exposure of the FA residues, thereby further facilitating the cellular-level targeting and uptake of the SLNs by the receptor-mediated endocytosis. The evaluation of the in vivo antitumor efficacy of the hierarchically targetable SLN therapy system by oral administration showed the effective inhibition of primary colon tumors and peritoneal metastasis in terms of the ascites volume and tumor nodule number and size, along with the absence of systemic side effects.

Targeted Delivery of Functionalized Upconversion Nanoparticles for Externally Triggered Photothermal/Photodynamic Therapies of Brain Glioblastoma.

Therapeutic efficacy of glioblastoma multiforme (GBM) is often severely limited by poor penetration of therapeutics through blood-brain barrier (BBB) into brain tissues and lack of tumor targeting. In this regard, a functionalized upconversion nanoparticle (UCNP)-based delivery system which can target brain tumor and convert deep tissue-penetrating near-infrared (NIR) light into visible light for precise phototherapies on brain tumor was developed in this work. Methods: The UCNP-based phototherapy delivery system was acquired by assembly of oleic acid-coated UCNPs with angiopep-2/cholesterol-conjugated poly(ethylene glycol) and the hydrophobic photosensitizers. The hybrid nanoparticles (ANG-IMNPs) were characterized by DLS, TEM, UV/vis and fluorescence spectrophotometer. Cellular uptake was examined by laser scanning confocal microscopy and flow cytometry. The PDT/PTT effect of ANG-IMNPs was evaluated using MTT assay. Tumor accumulation of NPs was determined by a non-invasive in vivo imaging system (IVIS). The in vivo anti-glioma effect of ANG-IMNPs was evaluated by immunohistochemical (IHC) examination of tumor tissues and Kaplan-Meier survival analysis. Results: In vitro data demonstrated enhanced uptake of ANG-IMNPs by murine astrocytoma cells (ALTS1C1) and pronounced cytotoxicity by combined NIR-triggered PDT and PTT. In consistence with the increased penetration of ANG-IMNPs through endothelial monolayer in vitro, the NPs have also shown significantly enhanced accumulation at brain tumor by IVIS. The IHC tissue examination confirmed prominent apoptotic and necrotic effects on tumor cells in mice receiving targeted dual photo-based therapies, which also led to enhanced median survival (24 days) as compared to the NP treatment without angiopep-2 (14 days). Conclusion: In vitro and in vivo data strongly indicate that the ANG-IMNPs were capable of selectively delivering dual photosensitizers to brain astrocytoma tumors for effective PDT/PTT in conjugation with a substantially improved median survival. The therapeutic efficacy of ANG-IMNPs demonstrated in this study suggests their potential in overcoming BBB and establishing an effective treatment against GBM.