Neglected immunoregulation: M2 polarization of macrophages triggered by low-dose irradiation plays an important role in bone regeneration.

Current studies have found that low-dose irradiation (IR) can promote bone regeneration. However, mechanism studies of IR-triggered bone regeneration mainly focus on the effects of osteoblasts, neglecting the role of the surrounding immune microenvironment. Here in this study, in vitro proliferation experiments showed that low-dose IR ≤2 Gy could promote the proliferation of bone marrow mesenchymal stem cells (BMSCs), and qRT-PCR assay showed that low-dose IR ≤2 Gy could exert the M2 polarization of Raw264.7 cells, while IR >2 Gy inhibited BMSC proliferation and triggered M1 polarization in Raw264.7 cells. The ALP and mineralized nodules staining showed that low-dose IR ≤2 Gy not only promoted osteoblast mineralization through IR-triggered osteoblast proliferation but also through M2 polarization of Raw264.7 cells, while high-dose IR >2 Gy had the opposite effect. The co-incubation of BMSC with low-dose IR irradiated Raw264.7 cell supernatants increased the mRNA expression of BMP-2 and Osx. The rat cranial defects model revealed that low-dose IR ≤2 Gy gradually promoted bone regeneration, while high-dose IR >2 Gy inhibited bone regeneration. Detection of macrophage polarity in peripheral blood samples showed that low-dose IR ≤2 Gy increased the expression of CD206 and CD163, but decreased the expression of CD86 and CD80 in macrophages, which indicated M2 polarization of macrophages in vivo, while high-dose IR had the opposite effect. Our finding innovatively revealed that low-dose IR ≤2 Gy promotes bone regeneration not only by directly promoting the proliferation of osteoblasts but also by triggering M2 polarization of macrophages, which provided a new perspective for immune mechanism study in the treatment of bone defects with low-dose IR.

Mechanisms of action of Zishen Yutai pills in treating premature ovarian failure determined by integrating UHPLC-Q-TOF-MS and network pharmacology analysis.

BACKGROUND: Zishen Yutai (ZSYT) pill, a patent Chinese medicine, has been widely used in the treatment of infertility, abortion, and adjunctive treatment of in vitro fertilization (IVF) for decades. Recently, the results of clinical observations showed that premature ovarian failure (POF) patients exhibited improved expression of steroids and clinical symptoms associated with hormone disorders after treatment with Zishen Yutai pills. However, the pharmacological mechanism of action of these pills remains unclear. METHODS: The compounds of Zishen Yutai pills found in blood circulation were identified via ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) technique in the serum of POF mice after oral administration of Zishen Yutai pills. The potential targets of compounds were screened using Traditional Chinese Medicine Systems Pharmacology Database, Traditional Chinese Medicine Database@Taiwan, Drugbank Database, PubChem, HIT, Pharmapper, and Swiss Target Prediction. The target genes associated with POF were collected from Online Mendelian Inheritance in Man Database, PharmGkb, Genecards, Therapeutic Target Database, and Genetic Association Database. The overlapping genes between the potential targets of Zishen Yutai pills' compounds and the target genes associated with POF were clarified via protein-protein interaction (PPI), pathway, and network analysis. RESULTS: Nineteen compounds in Zishen Yutai pills were detected in the serum of POF mice after oral administration. A total of 695 Zishen Yutai (ZSYT) pill-related targets were screened, and 344 POF-related targets were collected. From the results of Zishen Yutai (ZSYT) pill-POF PPI analysis, CYP19A1, AKR1C3, ESR1, AR, and SRD5A2 were identified as key targets via network analysis, indicating their core role in the treatment of POF with Zishen Yutai pills. Moreover, the pathway enrichment results suggested that Zishen Yutai pills treated POF primarily by regulating neuroactive ligand-receptor interaction, steroid hormone biosynthesis, and ovarian steroidogenesis. CONCLUSIONS: Via virtual screening, we found that regulation of neuroactive ligand-receptor interaction, steroid hormone biosynthesis, and ovarian steroidogenesis was the potential therapeutic mechanism of Zishen Yutai pills in treating POF. Our study suggested that combining the analysis of Zishen Yutai pills' compounds in blood in vivo in the POF model and network pharmacology prediction might offer a tool to characterize the mechanism of Zishen Yutai pills in the POF.

Mild Hyperthermia Induced by Hollow Mesoporous Prussian Blue Nanoparticles in Alliance with a Low Concentration of Hydrogen Peroxide Shows Powerful Antibacterial Effect.

The emergence of superbacteria as well as the drug resistance of the current bacteria gives rise to worry regarding a bacterial pandemic and also calls for the development of novel ways to combat the bacteria. Here in this article, we demonstrate that mild hyperthermia induced by hollow mesoporous Prussian blue nanoparticles (HMPBNPs) in alliance with a low concentration of hydrogen peroxide (H2O2) shows a powerful inhibition effect on bacteria. Our results demonstrate that this therapeutic regime could realize almost full growth inhibition of both Gram-positive (Staphylococcus aureus, S. aureus) and -negative bacteria (Escherichia coli, E. coli), as well as potent inhibition/elimination of the S. aureus biofilm. The wound healing results indicate that combination regime of the antibacterial system could be conveniently used for wound disinfection in vivo and could promote wound healing. To our limited knowledge, this is one of the few pioneer works to apply mild hyperthermia for the combat of bacteria, which provides a novel strategy to inspire future studies.

Nanodot-doped peptide hydrogels for antibacterial phototherapy and wound healing.

Bacterial infection of wounds delays the healing process, increases the risk of chronic trauma associated with pain and complications, and offers a breeding ground for drug-resistant bacteria. A rapid and effective eradication of the bacterial species in the wound area is thus important. Herein, we designed a phototherapeutic antibacterial platform based on peptides and copper sulfide nanodots (CuS NDs) for multi-mechanistic eradication of bacteria colonized on the wound surface. The antimicrobial peptide weaves into a network in the form of a hydrogel, which supports CuS NDs to generate heat and produce reactive oxygen species (ROS) under the irradiation of near-infrared light (NIR). The heat and ROS generated in situ act as non-contact-based antibacterial factors and together with contact-based antimicrobial peptides cause irreversible membrane destruction, cell content damage, and thermal ablation of the bacteria. Lastly, nanodot-doped peptide hydrogels combined with collagen showed complete bacterial elimination and significantly accelerated wound healing in a splint-fixed mouse infection model.

Inhibition of breast cancer proliferation and metastasis by strengthening host immunity with a prolonged oxygen-generating phototherapy hydrogel.

Hypoxia is a potent tumor microenvironmental (TME) factor promoting immunosuppression and metastatic progression. For current anticancer therapeutic strategies, the combination of hypoxia alleviation and photodynamic therapy (PDT) might be a useful approach to further improve anticancer efficacy. In this study, we alleviated tumor hypoxia using a prolonged oxygen-generating phototherapy hydrogel (POP-Gel), which effectively elevated the oxygen level and shrank the hypoxic regions of tumors for up to 5 days evaluated by photoacoustic (PA) imaging and immunofluorescence staining, meeting the requirement of the "once injection, sustained treatment" strategy and significantly increasing PDT efficacy. The long-period improvement of the tumor hostile environment downregulated the expression of hypoxia inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF), further preventing tumor growth and metastasis. More importantly, the enhanced PDT triggered a more intense immune response, improving the inhibition of triple negative breast cancer growth even tumor elimination. The POP-Gel may contribute useful insights into the combination of hypoxia alleviation and PDT.

Curcumin-coordinated nanoparticles with improved stability for reactive oxygen species-responsive drug delivery in lung cancer therapy.

BACKGROUND: The natural compound curcumin (Cur) can regulate growth inhibition and apoptosis in various cancer cell lines, although its clinical applications are restricted by extreme water insolubility and instability. To overcome these hurdles, we fabricated a Cur-coordinated reactive oxygen species (ROS)-responsive nanoparticle using the interaction between boronic acid and Cur. MATERIALS AND METHODS: We synthesized a highly biocompatible 4-(hydroxymethyl) phenylboronic acid (HPBA)-modified poly(ethylene glycol) (PEG)-grafted poly(acrylic acid) polymer (PPH) and fabricated a Cur-coordinated ROS-responsive nanoparticle (denoted by PPHC) based on the interaction between boronic acid and Cur. The mean diameter of the Cur-coordinated PPHC nanoparticle was 163.8 nm and its zeta potential was -0.31 mV. The Cur-coordinated PPHC nanoparticle improved Cur stability in physiological environment and could timely release Cur in response to hydrogen peroxide (H2O2). PPHC nanoparticles demonstrated potent antiproliferative effect in vitro in A549 cancer cells. Furthermore, the viability of cells treated with PPHC nanoparticles was significantly increased in the presence of N-acetyl-cysteine (NAC), which blocks Cur release through ROS inhibition. Simultaneously, the ROS level measured in A549 cells after incubation with PPHC nanoparticles exhibited an obvious downregulation, which further proved that ROS depression indeed influenced the therapeutic effect of Cur in PPHC nanoparticles. Moreover, pretreatment with phosphate-buffered saline (PBS) significantly impaired the cytotoxic effect of Cur in A549 cells in vitro while causing less damage to the activity of Cur in PPHC nanoparticle. CONCLUSION: The Cur-coordinated nanoparticles developed in this study improved Cur stability, which could further release Cur in a ROS-dependent manner in cancer cells.

Isotryptophan from Antarctic Bacillus amyloliquefaciens Pc3: purification, identification, characterization, and antifungal activity.

Strain Pc3 was isolated from Antarctic seawater and identified as Bacillus amyloliquefaciens. A compound with antifungal activity was purified from the fermentation supernatant of B. amyloliquefaciens Pc3. Its structure was determined to be (S)-2-amino-3-(1H-indol-2-yl) propanoic acid, named as isotryptophan, based on detailed analysis of its nuclear magnetic resonance (NMR) and high-resolution electrospray ionisation mass spectrometry (HR-ESI-MS). Isotryptophan exhibited good thermal stability and antifungal activity against several plant-pathogenic fungi with low minimum inhibitory concentrations. Therefore, the characterisation of isotryptophan from the Antarctic B. amyloliquefaciens Pc3 will facilitate its potential application in the control of plant-pathogenic fungal infection.