NIR-Triggered Multifunctional NO Nanoplatform for Conquering Thermal Resistance in Biofilms.

Photothermal treatment (PTT) has emerged as a promising avenue for biofilm elimination, yet its potential drawbacks, such as local hyperpyrexia and bacterial heat resistance, have posed challenges. To address these concerns, an innovative nanoplatform (Au@mSiO2-arg/ICG) is devised that integrates phototherapeutic and gas therapeutic functionalities. This multifaceted nanoplatform is composed of mesoporous silica-coated Au nanorods (Au@mSiO2), supplemented with l-arginine (l-arg) and indocyanine green (ICG), and is engineered for mild temperature PTT aimed at biofilm eradication. Au@mSiO2-arg/ICG nanoparticles (NPs) show excellent antibacterial effects through the generation of nitric oxide (NO) gas, heat, and reactive oxygen species (ROS) under 808 nm light irradiation. The ROS generated by ICG initiates a cascade reaction with l-arg, ultimately yielding NO gas molecules. This localized release of NO not only effectively curbs the expression of heat shock proteins 70 mitigating bacterial thermoresistance, but also reduces extracellular polymeric substance allowing better penetration of the therapeutic agents. Furthermore, this nanoplatform achieves an outstanding biofilm elimination rate of over 99% in an abscess model under 808 nm light irradiation (0.8 W·cm-2), thereby establishing its potential as a dependable strategy for NO-enhanced mild PTT and antibacterial photodynamic therapy (aPDT) in clinical settings.

Medical Applications and Advancement of Near Infrared Photosensitive Indocyanine Green Molecules.

Indocyanine green (ICG) is an important kind of near infrared (NIR) photosensitive molecules for PTT/PDT therapy as well as imaging. When exposed to NIR light, ICG can produce reactive oxygen species (ROS), which can kill cancer cells and pathogenic bacteria. Moreover, the absorbed light can also be converted into heat by ICG molecules to eliminate cancer cells. In addition, it performs exceptionally well in optical imaging-guided tumor therapy and antimicrobial therapy due to its deeper tissue penetration and low photobleaching properties in the near-infrared region compared to other dyes. In order to solve the problems of water and optical stability and multi-function problem of ICG molecules, composite nanomaterials based on ICG have been designed and widely used, especially in the fields of tumors and sterilization. So far, ICG molecules and their composite materials have become one of the most famous infrared sensitive materials. However, there have been no corresponding review articles focused on ICG molecules. In this review, the molecular structure and properties of ICG, composite material design, and near-infrared light- triggered anti-tumor, and antibacterial, and clinical applications are reviewed in detail, which of great significance for related research.

Near-infrared light-triggered nitric oxide nanocomposites for photodynamic/photothermal complementary therapy against periodontal biofilm in an animal model.

Background: Periodontal disease, an oral disease that initiates with plaque biofilm infection, affects 10% of the global population. Due to the complexity of tooth root anatomy, biofilm resistance and antibiotic resistance, traditional mechanical debridement and antibiotic removal of biofilms are not ideal. Nitric oxide (NO) gas therapy and its multifunctional therapy are effective methods to clear biofilms. However, large and controlled delivery of NO gas molecules is currently a great challenge. Methods: The core-shell structure of Ag2S@ZIF-90/Arg/ICG was developed and characterized in detail. The ability of Ag2S@ZIF-90/Arg/ICG to produce heat, ROS and NO under 808 nm NIR excitation was detected by an infrared thermal camera, probes and Griess assay. In vitro anti-biofilm effects were evaluated by CFU, Dead/Live staining and MTT assays. Hematoxylin-eosin staining, Masson staining and immunofluorescence staining were used to analyze the therapeutic effects in vivo. Results: Antibacterial photothermal therapy (aPTT) and antibacterial photodynamic therapy (aPDT) could be excited by 808 nm NIR light, and the produced heat and ROS further triggered the release of NO gas molecules simultaneously. The antibiofilm effect had a 4-log reduction in vitro. The produced NO caused biofilm dispersion through the degradation of the c-di-AMP pathway and improved biofilm eradication performance. In addition, Ag2S@ZIF-90/Arg/ICG had the best therapeutic effect on periodontitis and NIR II imaging ability in vivo. Conclusions: We successfully prepared a novel nanocomposite with NO synergistic aPTT and aPDT. It had an outstanding therapeutic effect in treating deep tissue biofilm infection. This study not only enriches the research on compound therapy with NO gas therapy but also provides a new solution for other biofilm infection diseases.

Effect of thermal processing for rutin preservation on the properties of phenolics & starch in Tartary buckwheat achenes.

The endogenous rutin-degrading enzymes (RDEs) in Tartary buckwheat (TB) considerably limit the development of TB functional foods. In this study, three thermal treatments, including superheated steam (SS), saturated steam (ST), and far-infrared drying (FID), were used to inactivate RDEs in TB. Results showed that SS and ST could efficiently inactivate RDEs, whereas FID could not. The extractable rutin contents in TB were increased by 52.3% and 12.3% by SS and ST, respectively, with 90 s of treatment time. Furthermore, the properties of phenolics and starch were used to evaluate the influence of thermal inactivation on TB. Results showed that the soluble phenolic compounds contents in TB were significantly improved (p < 0.05) by SS. The bound phenolic compounds contents were decreased after SS and ST treatments. The change in antioxidant properties was consistent with that of phenolics and flavonoids. Besides, the starch in SS- and ST-treated TB achenes had higher relative crystallinity, setback, transition temperatures, rapidly digestible starch, and slowly digestible starch contents, but a lower ratio of 1047 cm-1/1022 cm-1, peak viscosity, breakdown, gelatinization enthalpy, and resistant starch contents, than native TB starch. In conclusion, SS was a better method for the inactivation of RDEs than ST.

[A new benzamide derivative from rice fermentation of Streptomyces sp. CPCC 202950].

Eight compounds were isolated from the rice fermentation of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over silica, Sephadex LH-20, flash C18, and reversed-phase HPLC. Their structures were identified as 3-[(3'-amino-3'-oxoprop-1'-en-2'-yl)oxy]benzamide (1), m-hydroxybenzamide (2), leptosphaepin (3), 5-methyluracil (4), feruloylamide (5), p-hydroxyphenylacetoamide (6), vanillamide (7), cyclo (L-val-L-ala) (8). Among them, 1 was a new benzamide analogue, and 2 was a new natural product. In the preliminary assays, none of the compounds 1-8 exhibited obvious inhibition of HIV-1 protease activity, and toxic with the Hela, HepG2, and U2OS cells. (IC50 > 10 µmol•L⁻¹).

[Chemical constituents from culture of Streptomyces sp. CPCC 202950].

Eleven compounds were isolated from the culture of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over macroporous resin HP-20, MCI, and reversed-phase HPLC. Their structures were identified as 1H-pyrrole-2-carboxamide(1),5'-deoxy-5'-methylthioinosine(2), vanillamide(3), trans-3-methylthioacrylamide(4), 1,2,3,4-Tetraydro-1H-pyrido[3,4-b]indole-3-carboxylic acid(5), cyclo(L-pro-L-tyr) (6), N-[2-(4-hydroxyphenyl)]ethylacetamide(7), benzamide (8), cyclo ('L-leucyl-trans-4-hydroxy-L-proline)(9), cyclo-(Phe-Gly) (10), and tryptophan (11). Among them, compounds 1 and 2 were new natural products. In the preliminary assays, none of the compounds exhibited obvious inhibition of HIV-1 protease activity (IC50 > 10 micromol x L(-1)).

Multifunctional Au@mSiO2/rhodamine B isothiocyanate nanocomposites: cell imaging, photocontrolled drug release, and photothermal therapy for cancer cells.

The synthesis of Au@mesoporous SiO(2)/rhodamine B isothiocyanate (Au@mSiO(2)/RBITC) composite nanoparticles (NPs) is presented and their unique biofunctional properties are studied. The structure and morphology of the NPs are characterized by X-ray powder diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. These NPs can not only be functionalized for fluorescence imaging, but also possess well-defined mesopore structures for drug loading and strong infrared surface plasmon absorption for light-controlled drug release and photothermal therapy for cancer cells. In the biological experiments, one 808 nm laser is coupled to a confocal laser scanning microscopy (CLSM) system to monitor the photothermal therapy, drug release, and cell position and viability in real time by using the multichannel function of CLSM for the first time. Such novel nanomaterials offer a new chemotherapeutic route for cancer treatment by combining cell imaging and hyperthermia in a synergistic way.

12P-conjugated PEG-modified gold nanorods combined with near-infrared laser for tumor targeting and photothermal therapy.

Gold nanorods have been reported as potential tumor photothermal therapy in vivo and in vitro. However, development of the safe and efficient tumor-targeting gold nanorods for in vivo localized tumor therapy is still a challenge. In our present study, we synthesized the PEG modified gold nanorods and demonstrated its negligible cytotoxicity in vitro. These nanorods also have been demonstrated to efficiently ablate the different kinds of tumor cells in vitro after exposure to the near-infrared laser. When the PEG modified gold nanorods conjugated with the 12P (sequence: TACHQHVRMVRP), this conjugate showed great tumor-targeting and hyperthermia effects on the human liver cancer cell line HepG2 in vitro when coupled with the near-infrared laser treatment. To determine the potential hyperthermia effect of PEG modified gold nanorods or 12P conjugate on tumor cells in vivo, the mice hepatic cancer cells were used to induce the subcutaneous tumor-bearing model in ICR mice. The significant inhibition effects of near-infrared laser mediated PEG modified gold nanorods or 12P conjugate on the tumor growth were observed. These composite results suggest that the 12P-conjugated PEG modified gold nanorods exhibit great biocompatible, particular tumor-targeting and effective photothermal ablation of tumor cells, which warrant the potential therapeutic value of this conjugate for further application in in vivo localized tumor therapy.

Selective photothermal therapy for breast cancer with targeting peptide modified gold nanorods.

In this work, we prepared polyacrylic acid (PAA) coated gold nanorods (GNRs) and then the targeting peptide modified GNRs. The biocompatibility and stability of functionalized GNRs were investigated by monitoring the surface plasmon resonance (SPR) absorption intensity. The efficacy of targeted thermal therapy can be significantly enhanced via decoration with surface-bound peptide which was obtained through phage display technology. In addition, the photothermal therapy was monitored in real time with the multi-channel function of a confocal laser scanning microscope (CLSM) coupled with an 808 nm laser. This selective photothermal therapy of GNRs is a promising candidate for phototherapeutic applications.

[Anti-HIV activities of Achyranthes bidentata polysaccharide sulfate in vitro and in vivo].

Achyranthes bidentata polysaccharide sulfate (ABPS) was a sulfated derivate derived from Achyranthes bidentata polysaccharide (ABP) which was isolated and identified from Chinese herb Achyranthes bidentata. The anti human immunodeficiency virus type 1 (HIV-1) activities were studied in vitro and in vivo. ABPS was found to inhibit HIV-1 reverse transcriptase and integrase with the 50% inhibiting concentration (IC60) of (2.948 +/- 0.556) micromol x L(-1) and (0.155 +/- 0.030) micromol x L(-1), respectively, but the parent compound ABP was not effective. ABPS inhibited HIV-1 P24 antigen with IC50 of (0.082 +/- 0.044) micromol x L(-1) and selective index (SI) of > (358 +/- 148) in MT-4 cell cultures acutely infected with HIV-1 IIIB virus, and with IC50 of (11.80 +/- 5.90) micromol x L(-1) and SI of > (24.2 +/- 12.1) in PBMC cell cultures acutely infected with clinical isolated zidovudine resistant HIV-1 virus, but there was no activity even at its concentration of 500 micromol x L(-1) in latent infection of H9/HIV-1 IIIB cell cultures. 5% sera taken from rats after intraperitoneal injection from rats with ABPS 125 mg x kg(-1) once or mice with 3 mg x kg(-1) qd for 20 days effectively inhibited HIV-1 P24 in MT-4 cell cultures, but those had no inhibitory effect when given orally. The results suggested that ABPS is a promising HIV-1 inhibitor, active on HIV-1 reverse transcriptase, integrase in vitro and HIV-1 P24 antigens in cell cultures, it was well absorbed by intraperitoneal injection but poor in oral bioavailability. It warrants further study.

Three new derivatives of anti-HIV-1 polyphenols isolated from Salvia yunnanensis.

During the study of anti-HIV-1 active components of the aqueous extracts of the roots of Salvia yunnanensis, three new derivatives of polyphenols, namely: methyl salvianolate A (2), ethyl salvianolate A (3) and cis-lithospermic acid (5) were isolated along with two known polyphenols, salvianolic acid A (1) and lithospermic acid (4) their structures were elucidated on the basis of NMR and MS spectral analyses. The anti-HIV-1 activities of the 5 polyphenols were tested for the inhibition of P24 antigen in HIV-1 infected MT-4 cell cultures and HIV-1 replicative enzymes in vitro.