A promising theranostic platform for solid tumors would deliver and release anticancer nanomedicine effectively in tumor cells. However, diverse biological barriers, especially related to the tumor microenvironment, impede these theranostic agents from reaching the tumor cell. Herein, a sequential pH and reduction-responsive polymer and gold nanorod (AuNR) core-shell assembly to overcome these barriers via a two-stage size decrease and disassembly of the nano platform responding to the specified tumor microenvironment are reported. The tumor uptake of the hybrid nanoparticle (NP) is 14.2% ID g −1 , which is two and four times higher than the noneresponsive hybrid NPs and small AuNR@PEG, respectively. After tumor uptake of the hybrid NPs, the disassembled ultrasmall AuNRs coated with a polymer of polymerized reduction-responsive doxorubicin (DOX) prodrug monomers penetrate into the solid tumor and lead to localized DOX release in the tumor cell. A linear increase in photoacustic (PA) effects from the PA activating polymer on an AuNR cluster surface indicates a critical role of electromagnetic fields in the AuNR assembly, which is consistent with the theoretical calculation results. Furthermore, the hybrid NP can serve as a promising deep-tissue PA and surfaceenhanced Raman scattering imaging agent for real-time in vivo investigation of physiological behaviors and deep tumor penetrating nanotherapy effects.

Nanoparticles have been widely tested as drug delivery carriers or imaging agents, largely because of their ability to selectively accumulate in tumors through the enhanced permeability and retention (EPR) effect. However, studies show that many tumors afford a less efficient EPR effect and that many nanoparticles are trapped in the perivascular region after extravasation and barely migrate into tumor centers. This is to a large degree attributed to the dense tumor extracellular matrix (ECM), which functions as a physical barrier to prevent efficient nanoparticle extravasation and diffusion. In this study, we report a photodynamic therapy (PDT) approach to enhance tumor uptake of nanoparticles. Briefly, we encapsulate ZnFPc, a photosensitizer, into ferritin nanocages, and then conjugate to the surface of the ferritin a single chain viable fragment (scFv) sequence specific to fibroblast activation protein (FAP). FAP is a plasma surface protein widely upregulated in cancer-associated fibroblasts (CAFs), which is a major source of the ECM fiber components. We found that the scFv-conjugated and ZnFPc-loaded ferritin nanoparticles (scFv-Z@FRT) can mediate efficient and selective PDT, leading to eradication of CAFs in tumors. When tested in bilateral 4T1 tumor models, we found that the tumor accumulation of serum albumin (BSA), 10 nm quantum dots (QDs), and 50 nm QDs was increased by 2-, 3.5-, and 18-fold after scFv-Z@FRT mediated PDT. Our studies suggest a novel and safe method to enhance the delivery of nanoparticles to tumors.

BackgroundLong noncoding small nucleolar RNA host gene 16 (SNHG16) has been shown to play an oncogenic role in multiple cancers. However, the biological roles and mechanism of SNHG16 action in the regulation of papillary thyroid cancer (PTC) remains unknown. The aims of this study were to investigate the roles and the possible mechanism of SNHG16 in PTC progression.Materials and methodsThe expression of SNHG16 PTC tissues and cell lines was detected by reverse-transcription quantitative PCR (qRT-PCR). The effect of SNHG16 on cell proliferation, apoptosis, migration, and invasion was detected by Cell Counting Kit-8, flow cytometry, wound-healing assay, and Matrigel invasion assay, respectively. In addition, the regulatory relationships between SNHG16 and miR-497 were explored by luciferase reporter assay and qRT-PCR.ResultsThe SNHG16 expression was upregulated in PTC tissues and cell lines, whose expression was positively associated with advanced TNM stage and lymph node metastasis. Function analysis demonstrated that depletion of SNHG16 in PTC cells significantly inhibited cell proliferation, induced cell apoptosis, and suppressed cell migration and invasion abilities. Mechanistic studies indicated that SNHG16 functioned as an endogenous sponge for miR-497 to regulate its target genes brain-derived neurotrophic factor and yes-associated protein 1 expression. Furthermore, the inhibition of miR-497 antagonized the suppressive effect of SNHG16-depleted cells on cell proliferation, migration, and invasion.ConclusionThese findings revealed that SNHG16 drived the PTC progression possibly via regulating miR-497, suggesting that SNHG16 might be a novel therapeutic agent for PTC.