Hyaluronic acid-coated porphyrin nanoplatform with oxygen sustained supplying and glutathione depletion for enhancing photodynamic/ion/chemo synergistic cancer treatment.

Hypoxia and high concentration of glutathione (GSH) in tumor seriously hinder the role of reactive oxygen species (ROS) and oxygen-dependence strategy in tumor treatment. In this work, a self-generating oxygen and self-consuming GSH hyaluronic acid (HA)-coated porphyrin nanoplatform (TAPPP@CaO2/Pt(IV)/HA) is established for enhancing photodynamic/ion/chemo targeting synergistic therapy of tumor. During the efforts of ROS production by nanosystems, a GSH consuming strategy is implemented for augmenting ROS-induced oxidative damage for synergetic cancer therapy. CaO2 in the nanosystems is decomposed into O2 and H2O2 in an acidic environment, which alleviates hypoxia and enhances the photodynamic therapy (PDT) effect. Calcium overload causes mitochondria dysfunction and induces apoptosis. Pt (IV) reacts with GSH to produce Pt (II) for chemotherapy and reduce the concentration of GSH, protecting ROS from scavenging for augmenting ROS-induced oxidative damage. In vitro and in vivo results demonstrated the self-generating oxygen and self-consuming GSH strategy can enhance ROS-dependent PDT coupled with ion/chemo synergistic therapy. The proposed strategy not only solves the long-term problem that hypoxia limits therapeutic effect of PDT, but also ameliorates the highly reducing environment of tumors. Thus the preparation of TAPPP@CaO2/Pt(IV)/HA provided a novel strategy for the effective combined therapy of cancers.

Anti-photoaging activity of triterpenoids isolated from Centella asiatica.

Centella asiatica (L.) Urban is a medical plant rich in triterpenoids, frequently used in Asia to treat skin conditions such as acne. To search for anti-photoaging agents, 16 known triterpenoids and five undescribed triterpenoids, including three ursane, one oleanane and one nor-ursane were isolated from the whole herb of C. asiatica. The structures and relative stereochemistry of these compounds were elucidated by detailed NMR spectra and HRESIMS. Compounds 1 and 2 were isomers of ursane-type and oleane-type triterpenes with rare aldehyde groups on C-23. Compound 4 was a unique example of a nor-ursane type triterpenoid. The Ultraviolet B (UVB) induced HaCaT cell damage model was used to measure the in vitro anti-photoaging activity of all 21 compounds. Twenty compounds significantly increased HaCaT viability and inhibited lactate dehydrogenase (LDH) release after UVB exposure. These findings highlight the protective effects of C. asiatica-derived triterpenoids against UVB damage and indicate their potential as natural agents that can protect the skin against photoaging.