Gambogic acid and IR780 self-assembled nanoparticles for combined chemo-phototherapy.

Combined chemo-phototherapy has shown considerable advantages and potential in cancer treatment. For this purpose, self-assembled nanoparticles by gambogic acid (GA) and IR780 (referred to as GA-IR780 NPs) were prepared. Herein, GA, an active compound derived from Garcinia hanburyi Hook.f, was selected as a chemo-agent. IR780 was used as a photothermal agent as well as a photosensitizer, which could kill tumor cells via photothermal effect and photodynamic effect. The obtained GA-IR780 NPs were uniform spheres with particle size of ca. 50 nm. The drug loading efficiency of GA and IR780 was 38.42 % and 56.64 %, respectively. The GA-IR780 NPs exhibited excellent photothermal properties as well as photodynamic effect when irradiated by near infrared (NIR) light (808 nm, 2.0 W/cm2). Moreover, the GA-IR780 NPs showed enhanced cytotoxicity with NIR light activation. Results of animal experiments showed that GA-IR780 NPs had the most significant tumor inhibition when irradiated by laser, and the results of H&E, Ki-67 and TUNEL staining confirmed that the GA-IR780 NPs+Laser group caused the most severe tumor tissue damage. The above results indicated that GA-mediated chemotherapy combining with IR780-based phototherapy could significantly improve the anti-tumor efficacy.

Poly-tannic acid coated PLGA nanoparticle decorated with antimicrobial peptide for synergistic bacteria treatment and infectious wound healing promotion.

Bacterial infections pose a great threat to human health. Therefore, the development of new antibacterial agents or methods is in urgent need. In this study, we prepared polytannic acid (pTA)-coated PLGA nanoparticles decorated with Dermaseptin-PP (Der), an antimicrobial peptide (AMP), on the surface to obtain PLGA-pTA-Der. This nanoplatform could combine AMPs with photothermal treatment (PTT) mediated by pTA to achieve synergistic bacterial killing. The results of in vitro experiments showed that the PLGA-pTA-Der nanoparticles could eliminate nearly 99 % of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) upon near-infrared (NIR) laser irradiation (2.0 W·cm-2, 5 min), demonstrating excellent antibacterial properties. In addition, the results of atomic force microscopy (AFM) revealed that PLGA-pTA-Der with laser irradiation can greatly destroy the mechanical integrity of the bacterial outer membrane. And the presence of Der could exacerbate the heat damage caused by the PLGA-pTA NPs to the bacteria, which is helpful to reduce the critical temperature required for bacteria killing by PTT. In vivo experiments showed that PLGA-pTA-Der nanoparticles with laser irradiation significantly accelerated the wound healing process and inhibited the growth of bacterial. Moreover, it can achieve a strong photothermal antibacterial effect at a mild temperature (<45℃) and does not cause any obvious thermal damage to the surrounding normal skin tissues. Results of immunofluorescence staining showed that the expression of CD31 (a marker of new blood vessel formation) was significantly higher in the PLGA-pTA-Der + laser group than other groups, while the pro-inflammatory molecule TNF-α was significantly lower, indicating that PLGA-pTA-Der nanoparticles accelerated wound healing by enhancing angiogenesis and reducing the inflammatory response. In conclusion, PLGA-pTA-Der nanoparticles was a promising antimicrobial nanoplatform for treating bacterial infections and promoting wound healing.

Reinterpreting the Intercalation-Conversion Mechanism of FeP Anodes in Lithium/Sodium-Ion Batteries from Evolution of the Magnetic Phase.

Batteries with intercalation-conversion-type electrodes tend to achieve high-capacity storage, but the complicated reaction process often suffers from confusing electrochemical mechanisms. Here, we reinterpreted the essential issue about the potential of the conversion reaction and whether there is an intercalation reaction in a lithium/sodium-ion battery (LIB/SIB) with the FeP anode based on the evolution of the magnetic phase. Especially, the ever-present intercalation process in a large voltage range followed by the conversion reaction with extremely low potential was confirmed in FeP LIB, while it is mainly the conversion reaction for the sodium storage mechanism in FeP SIB. The insufficient conversion reaction profoundly limits the actual capacity to the expectedly respectable value. Accordingly, a graphene oxide modification strategy was proposed to increase the reversible capacity of FeP LIB/SIB by 99% and 132%, respectively. The results facilitate the development of anode materials with a high capacity and low operating potential.

Tuning transverse anisotropy in Co(III)-Co(II)-Co(III) mixed-valence complex toward slow magnetic relaxation.

Two cobalt mixed-valence complexes with different substituents have been prepared and structurally characterized by single-crystal X-ray diffraction to alter slow magnetic relaxation by tailoring the transverse anisotropy. The trinuclear complexes [(L(1))4Co3(H2O)2](NO3)4·CH3OH·5H2O (1-NO3) and [(L(2))4Co3(H2O)2](NO3)4·6H2O (2-NO3) feature a distorted octahedral Co(II) strongly hindered in a trinuclear Co(III)-Co(II)-Co(III) mixed-valence array. Detailed magnetic studies of 1-NO3 and 2-NO3 have been conducted using direct- and alternating-current magnetic susceptibility data. In accordance with variable-field magnetic susceptibility data at low temperatures, high-field electron paramagnetic resonance (HF-EPR) spectroscopy reveals the presence of an easy-plane anisotropy (D > 0) with a significant transverse component, E, in complexes 1-NO3 and 2-NO3. These findings indicate that the onset of the variation of distortion within complex 2-NO3 leads to a suppression of quantum tunneling of the magnetization within the easy plane, resulting in magnetic bistability and slow relaxation behavior. Consequently, the anisotropy energy scale associated with the relaxation barrier, 5.46 cm(-1) (τo = 1.03 × 10(-5) s), is determined by the transverse E term. The results demonstrate that slow magnetic relaxation can be switched through optimization of the transverse anisotropy associated with magnetic ions that possess easy-plane anisotropy.