Thermosensitive and tum or microenvironment activated nanotheranostics for the chemodynamic/photothermal therapy of colorectal tumor

This research proposes the one-pot preparation of polydopamine (PDA) decorated mesoporoussilica nanoparticle (PMSN) for the thermal and tumor micro-environment (TME) responsive colorectal tumor therapy. The pores of PMSN were used for the Fe³⁺ loading. Lauric acid (LA), a phase-change ligand, was selected as a "doorkeeper" to coat the surface of Fe³⁺-loaded PMSN and prevent the undesired leakage of Fe³⁺. Bovine serum albumin (BSA) was selected as a stabilizer to endow the PMSN-Fe-LA-BSA nanopartilces (PMFLB) with colloidal stability. Under the near infrared laser, the light-sensitive PDA produced significant heat to kill the colorectal cancer cells via hyperthermia. Moreover, the heat induced the phase-change of LA and triggered the release of Fe³⁺, which further reacted with the endogenous H₂S in the colorectal TME. After that, the Fe³⁺ was transformed into Fe²⁺, which triggered the Fenton reaction with the H₂O₂ in the TME and effectively generated hydroxyl radical (·OH). Finally, the Fe²⁺ was transformed into Fe³⁺, which repeatedly reacted with the H₂S and produced more ·OH to enhance the chemodynamic therapy of colorectal tumor. Such a thermosensitive PMFLB which operates in synergy with the colorectal TME opens an alternative avenue for the rational design of multifunctional nano-therapeutic agents.

Transformation pathways and fate of engineered nanoparticles (ENPs) in distinct interactive environmental compartments: A review

The ever increasing production and use of nano-enabled commercial products release the massive amount of engineered nanoparticles (ENPs) in the environment. An increasing number of recent studies have shown the toxic effects of ENPs on different organisms, raising concerns over the nano-pollutants behavior and fate in the various environmental compartments. After the release of ENPs in the environment, ENPs interact with various components of the environment and undergoes dynamic transformation processes. This review focus on ENPs transformations in the various environmental compartments. The transformation processes of ENPs are interrelated to multiple environmental aspects. Physical, chemical and biological processes such as the homo- or hetero-agglomeration, dissolution/sedimentation, adsorption, oxidation, reduction, sulfidation, photochemically and biologically mediated reactions mainly occur in the environment consequently changes the mobility and bioavailability of ENPs. Physico-chemical characteristics of ENPs (particle size, surface area, zeta potential/surface charge, colloidal stability, and core-shell composition) and environmental conditions (pH, ionic strength, organic and inorganic colloids, temperature, etc.) are the most important parameters which regulated the ENPs environmental transformations. Meanwhile, in the environment, organisms encountered multiple transformed ENPs rather than the pristine nanomaterials due to their interactions with various environmental materials and other pollutants. Thus it is the utmost importance to study the behavior of transformed ENPs to understand their environmental fate, bioavailability, and mode of toxicity.

Novel half-sandwich rhodium(III) and iridium(III) photosensitizers for dual chemo- and photodynamic therapy

BACKGROUND AND OBJECTIVE

Photodynamic therapy has emerged as a promising treatment for cancer and other malignancies. Design of photosensitizers with two different action mechanisms may be an essential strategy for the improvement of the efficacy of phototherapeutic drugs. The objective of this study was to evaluate the anticancer photo- and chemocytotoxic effects of the novel half-sandwich rhodium(III) and iridium(III) photosensitizers.

MATERIALS AND METHODS

A series of novel half-sandwich Cp*-Rh(III) and Cp*-Ir(III) complexes containing 9-anthraldehyde thiosemicarbazones, (Cp*)M(L)Cl (M = Rh or Ir, L = 9-anthraldehyde thiosemicarbazones), were compared for cell uptake and photo- and chemocytotoxic effects against human prostate carcinoma (PC3) and human ovarian carcinoma (SKOV3) cell lines.

RESULTS

Cp*-Ir(III) complexes, (Cp*)Ir(L)Cl, showed remarkable phototoxic behavior against human ovarian adenocarcinoma SKOV3 cells (IC₅₀ = 2.7 and 2.3 μM, respectively, λ_irr > 400 nm), as well as the 7.4 and 5.3-fold lower toxicity in the dark, implying possibility of dual action as chemo- and phototherapeutic agents.

CONCLUSION

The complexes, which present a synergistic effect with good properties of both the Cp*-Rh(III) and Cp*-Ir(III) chemotherapeutic effect and the anthracene photodynamic therapy efficiency, show great potential as a new generation of light activated dual-action anticancer agents for photodynamic therapy.