Low-level laser therapy with different irradiation methods modulated the response of bone marrow mesenchymal stem cells in vitro.

Low-level laser therapy (LLLT) also known as photobiomodulation is a treatment to change cellular biological activity. The exact effects of LLLT remain unclear due to the different irradiation protocols. The purpose of this study was to investigate the effects of LLLT by three different irradiation methods on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro. BMSCs were inoculated in 24-well plates and then irradiated or not (control) with a laser using three different irradiation methods. The irradiation methods were spot irradiation, covering irradiation, and scanning irradiation according to different spot areas (0.07 cm2 or 1.96 cm2) and irradiation areas (0.35 cm2 or 1.96 cm2), respectively. The laser was applied three times at energy densities of 4 J/cm2. The cell proliferation by CCK-8. ALP activity assay, alizarin red, and quantitative real-time polymerase chain reaction (RT-PCR) were performed to assess osteogenic differentiation and mineralization. Increases in cell proliferation was obvious following irradiation, especially for covering irradiation. The ALP activity was significantly increased in irradiated groups compared with non-irradiated control. The level of mineralization was obviously improved following irradiation, particularly for covering irradiation. RT-PCR detected significantly higher expression of ALP, OPN, OCN, and RUNX-2 in the group covering than in the others, and control is the lowest. The presented results indicate that the biostimulative effects of LLLT on BMSCs was influenced by t he irradiation method, and the covering irradiation is more favorable method to promote the proliferation and osteogenic differentiation of BMSCs.

Self-Propelled and Near-Infrared-Phototaxic Photosynthetic Bacteria as Photothermal Agents for Hypoxia-Targeted Cancer Therapy.

Hypoxia can increase the resistance of tumor cells to radiotherapy and chemotherapy. However, the dense extracellular matrix, high interstitial fluid pressure, and irregular blood supply often serve as physical barriers to inhibit penetration of drugs or nanodrugs across tumor blood microvessels into hypoxic regions. Therefore, it is of great significance and highly desirable to improve the efficiency of hypoxia-targeted therapy. In this work, living photosynthetic bacteria (PSB) are utilized as hypoxia-targeted carriers for hypoxic tumor therapy due to their near-infrared (NIR) chemotaxis and their physiological characteristics as facultative aerobes. More interestingly, we discovered that PSB can serve as a kind of photothermal agent to generate heat through nonradiative relaxation pathways due to their strong photoabsorption in the NIR region. Therefore, PSB integrate the properties of hypoxia targeting and photothermal therapeutic agents in an "all-in-one" manner, and no postmodification is needed to achieve hypoxia-targeted cancer therapy. Moreover, as natural bacteria, noncytotoxic PSB were found to enhance immune response that induced the infiltration of cytotoxicity T lymphocyte. Our results indicate PSB specifically accumulate in hypoxic tumor regions, and they show a high efficiency in the elimination of cancer cells. This proof of concept may provide a smart therapeutic system in the field of hypoxia-targeted photothermal therapeutic platforms.

Assemblies of indocyanine green and chemotherapeutic drug to cure established tumors by synergistic chemo-photo therapy.

Indocyanine green (ICG), a safe and clinically approved near-infrared (NIR) dye, was recently explored as a potential photosensitizer due to its excellent photophysical properties. However, ICG tends to form aggregations in physiological solution, causing fluorescence quenching, fast blood clearance and thereby inefficient tumor accumulation. Herein, we report ICG-based nanodrug delivery systems formed by self-assembly of ICG and chemotherapeutic drugs without any excipients for combined chemo- and photo-therapy. Taking advantage of the amphiphilic aromatic structure, ICG readily bounded with hydrophobic aromatic drugs such as SN38 and formed well-dispersible nanoparticles, which reduced its aggregation-induced quenching and thus greatly improved its photodynamic efficiency. The loaded hydrophobic drugs elicited chemotherapy synergizing the photodynamic therapy, giving rise to much enhanced antitumor activity in vitro and in vivo against human glioblastoma cells and breast cancer cells upon NIR irradiation. The work demonstrates the fabrication of readily translational nanoformulations of hydrophobic drugs using amphiphilic drugs.

Amino acids signatures of distance-related surgical margins of oral squamous cell carcinoma.

BACKGROUND: Histological assessment of resected margins has some drawbacks. We therefore aimed to identify a panel of metabolic markers for evaluating the surgical margins of oral squamous cell carcinoma during surgery. METHODS: A total of 28 case of OSCC samples were enrolled in the study. Gas chromatography-mass spectrometry based untargeted metabolic analysis was employed to acquire the metabolic perturbation of the distance-related surgical margins in the development group. The acquired MS data were then subjected to univariate and multivariate analysis by MetaboAnalyst. Ultra-high performance liquid chromatography-tandem mass spectrometerbased targeted metabolomics for quantitative analysis of the validation group was performed to verify the results of the development group. Another 60 OSCC patients with dysplastic surgical margins were used to further validate the results of the development group by immunohistochemical examination of key enzyme expression, and correlate them with clinicopathological parameters and clinical outcomes. FINDINGS: We finally identified 4 amino acids as negative margin markers, and 6 amino acids as dysplastic margin markers. IHC analysis showed that asparagine synthetase positive expression in dysplastic surgical margins and its higher expression was correlated with tumor recurrence and local relapse-free survival. INTERPRETATIONS: We developed a panel of metabolic molecular markers to supplement the evaluation of negative and dysplastic margins. FUND: This study was supported by Nanjing Municipal Key Medical Laboratory Constructional Project Funding (Since 2012); Center of Nanjing Clinical Medicine Tumor (Since 2014). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Porous Organic Polymer-Coated Band-Aids for Phototherapy of Bacteria-Induced Wound Infection.

Band-Aids have been widely used for wound care. For most adhesive bandages, however, they have a limited capacity to speed up the wound healing process, which in turn may cause serious wound infections. In this study, antibacterial Band-Aids, combining porphyrin-based porous organic polymers (POPs) with commercial antibiotic-free Band-Aids, are designed. Under white light irradiation, POPs can produce effective photothermal heat, as well as highly reactive oxygen species (ROS), thereby triggering the potent hyperthermia and simultaneous ROS increase on wounds. Additionally, white light is similar to sunlight, which makes POP-based Band-Aids (PBAs) ideal wound dressings for wound disinfection.

Targeting regenerative exosomes to myocardial infarction using cardiac homing peptide.

Rationale: Cardiac stem cell-derived exosomes have been demonstrated to promote cardiac regeneration following myocardial infarction in preclinical studies. Recent studies have used intramyocardial injection in order to concentrate exosomes in the infarct. Though effective in a research setting, this method is not clinically appealing due to its invasive nature. We propose the use of a targeting peptide, cardiac homing peptide (CHP), to target intravenously-infused exosomes to the infarcted heart. Methods: Exosomes were conjugated with CHP through a DOPE-NHS linker. Ex vivo targeting was analyzed by incubating organ sections with the CHP exosomes and analyzing with fluorescence microscopy. In vitro assays were performed on neonatal rat cardiomyocytes and H9C2 cells. For the animal study, we utilized an ischemia/reperfusion rat model. Animals were treated with either saline, scramble peptide exosomes, or CHP exosomes 24 h after surgery. Echocardiography was performed 4 h after surgery and 21 d after surgery. At 21 d, animals were sacrificed, and organs were collected for analysis. Results: By conjugating the exosomes with CHP, we demonstrate increased retention of the exosomes within heart sections ex vivo and in vitro with neonatal rat cardiomyocytes. In vitro studies showed improved viability, reduced apoptosis and increased exosome uptake when using CHP-XOs. Using an animal model of ischemia/reperfusion injury, we measured the heart function, infarct size, cellular proliferation, and angiogenesis, with improved outcomes with the CHP exosomes. Conclusions: Our results demonstrate a novel method for increasing delivery of for treatment of myocardial infarction. By targeting exosomes to the infarcted heart, there was a significant improvement in outcomes with reduced fibrosis and scar size, and increased cellular proliferation and angiogenesis.