A Smart Multifunctional Nanoparticle for Enhanced Near-Infrared Image-Guided Photothermal Therapy Against Gastric Cancer.

BACKGROUND: Surgery is considered to be a potentially curative approach for gastric cancer. However, most cases are diagnosed at a very advanced stage for the lack of typical symptoms in the initial stage, which makes it difficult to completely surgical resect of tumors. Early diagnosis and precise personalized intervention are urgent issues to be solved for improving the prognosis of gastric cancer. Herein, we developed an RGD-modified ROS-responsive multifunctional nanosystem for near-infrared (NIR) imaging and photothermal therapy (PTT) against gastric cancer. METHODS: Firstly, the amphiphilic polymer was synthesized by bromination reaction and nucleophilic substitution reaction of carboxymethyl chitosan (CMCh) and 4-hydroxymethyl-pinacol phenylborate (BAPE). Then, it was used to encapsulate indocyanine green (ICG) and modified with RGD to form a smart multifunctional nanoparticle targeted to gastric cancer (CMCh-BAPE-RGD@ICG). The characteristics were determined, and the targeting capacity and biosafety were evaluated both in vitro and in vivo. Furthermore, CMCh-BAPE-RGD@ICG mediated photothermal therapy (PTT) effect was studied using gastric cancer cells (SGC7901) and SGC7901 tumor model. RESULTS: The nanoparticle exhibited suitable size (≈ 120 nm), improved aqueous stability, ROS-responsive drug release, excellent photothermal conversion efficiency, enhanced cellular uptake, and targeting capacity to tumors. Remarkably, in vivo studies suggested that CMCh-BAPE-RGD@ICG could accurately illustrate the location and margin of the SGC7901 tumor through NIR imaging in comparison with non-targeted nanoparticles. Moreover, the antitumor activity of CMCh-BAPE-RGD@ICG-mediated PTT could effectively suppress tumor growth by inducing necrosis and apoptosis in cancer cells. Additionally, CMCh-BAPE-RGD@ICG demonstrated excellent biosafety both in vitro and in vivo. CONCLUSION: Overall, our study provides a biocompatible theranostic nanoparticle with enhanced tumor-targeting ability and accumulation to realize NIR image-guided PTT in gastric cancer.

Π electron-stabilized polymeric micelles potentiate docetaxel therapy in advanced-stage gastrointestinal cancer.

Gastrointestinal (GI) cancers are among the most lethal malignancies. The treatment of advanced-stage GI cancer involves standard chemotherapeutic drugs, such as docetaxel, as well as targeted therapeutics and immunomodulatory agents, all of which are only moderately effective. We here show that Π electron-stabilized polymeric micelles based on PEG-b-p(HPMAm-Bz) can be loaded highly efficiently with docetaxel (loading capacity up to 23 wt%) and potentiate chemotherapy responses in multiple advanced-stage GI cancer mouse models. Complete cures and full tumor regression were achieved upon intravenously administering micellar docetaxel in subcutaneous gastric cancer cell line-derived xenografts (CDX), as well as in CDX models with intraperitoneal and lung metastases. Nanoformulated docetaxel also outperformed conventional docetaxel in a patient-derived xenograft (PDX) model, doubling the extent of tumor growth inhibition. Furthermore, micellar docetaxel modulated the tumor immune microenvironment in CDX and PDX tumors, increasing the ratio between M1-and M2-like macrophages, and toxicologically, it was found to be very well-tolerated. These findings demonstrate that Π electron-stabilized polymeric micelles loaded with docetaxel hold significant potential for the treatment of advanced-stage GI cancers.

Co-encapsulation of magnetic Fe3O4 nanoparticles and doxorubicin into biocompatible PLGA-PEG nanocarriers for early detection and treatment of tumours.

At present, cancer is the first cause of death for humans, but early detection and treatment can help improve prognoses and reduce mortality. However, further development of carrier-assistant drug delivery systems (DDSs) is retarded by the aspects such as the low drug-carrying capacity, carrier-induced toxicity and immunogenicity, complex synthesis manipulation. The development of nanoscale drug delivery systems (NDDS) have been rapidly developed to address these issues. In this article, we used PLGA-PEG with good biocompatibility to encapsulate Fe3O4 nanoparticles (a magnetic resonance imaging contrast agent) and DOX (an antitumour drug) via the emulsion-solvent evaporation method, aimed at achieving a dual function of the early detection and the treatment of mammary cancer. The results showed that the Fe3O4/DOX/PLGA-PEG nanoparticles had a relatively uniform size, a high carrier rate of Fe3O4 and high encapsulation efficiency of DOX, and a relatively high activity of released DOX within 120 h. In addition, in vitro studies showed that the Fe3O4/DOX/PLGA-PEG nanoparticles were cytocompatibility in NIH 3T3 fibroblast cells culture study while had a special effect on destroying human breast cancer MCF-7 cells compared with pure DOX solution. In vitro studies revealed that the Fe3O4/DOX/PLGA-PEG enabled enhanced T2 contrast magnetic resonance. Overall, our multifunctional Fe3O4/DOX/PLGA-PEG nanoparticles, composed of biocompatible substances and therapeutic/imaging materials, have great potential for the early detection of cancer and accurate drug delivery via the dynamic monitoring using MRI.