No abstract

Nanosized constructs are widely applied to address the common drawbacks of conventional cancer therapy, such as a nonspecific biodistribution, toxicity and targeting. Nevertheless, there are several challenges in transporting sufficient drugs to the tumor using these nanoconstructs, which are discussed in this review. Additionally, the current opportunities that improve the biodistribution of nanoconstructs, tumor penetration and drug accumulation are elaborated. The distinct features of currently available strategies do not adequately fit the classical passive and active targeting categories; therefore, in this review, they are regrouped into autonomous and nonautonomous drug delivery systems. Autonomous systems are defined as self-directed systems that can enhance nanoparticle retention and distribution in solid tumors without the need to align with the blood flow direction, while non-autonomous systems primarily rely on the blood flow direction, longevity in the circulation and specific affinity to the target cells. Moreover, the effectiveness of the existing delivery systems could be further improved through the correct choice of route of administration. The role of the route of administration in improving these drug delivery methods and some recent examples of locoregional cancer therapy are discussed. These findings could stimulate improvements in the delivery of multifunctional nanoconstructs, which could facilitate successful cancer treatments.

Photosensitizing nanogels were obtained through a surfactant-free single-step protocol by using a porphyrin-based cross-linker for stabilizing self-assembled nanosized aggregates of thermoresponsive copolymers. Nanogels with varying amounts of porphyrin retained the singlet oxygen generation ability of the porphyrin core and were also capable of inducing temperature increase upon irradiation at 635 nm. Photoinduced killing efficiency was tested against three cell lines: human breast adenocarcinoma (MDA-MB-231 and MCF7) and pancreatic adenocarcinoma (AsPC-1) cells, and a predominant photodynamic mechanism at 450 nm and a mixed photodynamic and photothermal effect at 635 nm was observed. This innovative access to photosensitizing nanogels is a proof of concept, and opens new perspectives toward the preparation of optimized nanophotosensitizers.

The use of nanocarriers to improve the delivery and efficacy of antimetastatic agents is less explored when compared to cytotoxic agents. This study reports the entrapment of an antimetastatic Signal Transducer and Activator of Transcription 3 (STAT3) dimerization blocker, Stattic (S) into a chitosan-coated-poly(lactic-co-glycolic acid) (C-PLGA) nanocarrier and the improvement on the drug's physicochemical, in vitro and in vivo antimetastatic properties post entrapment. Methods: In vitro, physicochemical properties of the Stattic-entrapped C-PLGA nanoparticles (S@C-PLGA) and Stattic-entrapped PLGA nanoparticles (S@PLGA, control) in terms of size, zeta potential, polydispersity index, drug loading, entrapment efficiency, Stattic release in different medium and cytotoxicity were firstly evaluated. The in vitro antimigration properties of the nanoparticles on breast cancer cell lines were then studied by Scratch assay and Transwell assay. Study on the in vivo antitumor efficacy and antimetastatic properties of

No abstract