Enhancing the Electron Transport, Quantum Yield, and Catalytic Performance of Carbonized Polymer Dots via MnO Bridges.

Carbonized polymer dots (CPDs) have received tremendous attention during the last decade due to their excellent fluorescent properties and catalytic performance. Doping CPDs with transition metal atoms accelerates the local electron flow in CPDs and improves the fluorescent properties and catalytic performance of the CPDs. However, the binding sites and the formation mechanisms of the transition-metal-atom-doped CPDs remain inconclusive. In this work, Mn2+ -ion-doped CPDs (Mn-CPDs) are synthesized by the hydrothermal method. The Mn2+ ions form MnO bonds that bridge the sp2 domains of carbon cores and increases the effective sp2 domains in the Mn-CPDs, which redshifts the fluorescence emission peak of the Mn-CPDs slightly. The Mn2+ ions form covalent bonds in the CPDs and remedy the oxygen vacancies of the CPDs, which cuts off the non-radiative-recombination process of the Mn-CPDs and increases the quantum yield of the Mn-CPDs to 70%. Furthermore, the MnO bonds accelerate the electron flow between adjacent sp2 domains and enhances the electron transport in the Mn-CPDs. Thus, the Mn-CPDs demonstrate excellent catalytic performance to activate hydrogen peroxide (H2 O2 ) and produce hydroxyl radicals (•OH) to degrade methylene blue (MB) and rhodamine B (RhB).

Albendazole solid dispersions prepared using PEG6000 and Poloxamer188: formulation, characterization and in vivo evaluation.

This study aimed to optimize the preparation process of albendazole (ABZ) solid dispersion (SD) and enhance its dissolution rate and oral bioavailability in dogs. The ABZ-SD formulations were prepared by a fusion method with ABZ and polyethylene glycol 6000 (PEG 6000), poloxamer 188 (P 188) polymers at various weight ratios or the combination of PEG 6000&P 188. The characterizations of the optimal formulations were performed by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), in vitro dissolution test and molecular docking. The in vivo pharmacokinetic study was conducted in beagle dogs. As a result, ABZ solid dispersion based on PEG 6000&P 188 (1:2) was successfully prepared. The ABZ-SD formulation could significantly improve the apparent solubility and dissolution rate of ABZ compared with commercial tablets. Furthermore, the water solubility of ABZ-SD was improved mainly based on hydrogen bond association. Besides, at an oral dosage of 15 mg/kg ABZ, the SDs had higher Cmax values and areas under the curve (AUCs) compared to those of commercial ABZ tablets. Preparation of ABZ-loaded SDs by PEG 6000&P 188 is a promising strategy to improve the oral bioavailability of ABZ.

Protective role of α2-macroglobulin against jaw osteoradionecrosis in a preclinical rat model.

OBJECTIVE: We have previously demonstrated the effect of alpha-2-macroglobulin (α2M) in the remediation of radiation-induced cellular damage. Here, we investigated the protective effects of α2M in a preclinical rat model of jaw osteoradionecrosis (ORN). METHODS: Eighteen rats were divided randomly into three groups: the control group, the radiation therapy (RT) alone group, and the radiated mandibles pretreated with α2M (α2M + RT) group. One month after radiation, all left molar teeth were extracted. After another 3 months, the animals were sacrificed and body weight, histopathology, microcomputed tomography and immunofluorescence were evaluated in all groups. RESULTS: The RT group showed serious alopecia, bone exposure, inflammation, necrosis, fibrosis, and the absence of new bone formation within the socket. The α2M + RT group exhibited less alopecia than the RT group and slight inflammation and fibrosis in the bone marrow cavity. The cortical bone was similar to normal bone tissue. Interestingly, compared with RT group, serum superoxide dismutase levels in the α2M + RT group increased at the 1th day (P = 0.037), 14th day (P = 0.012), while reactive oxygen species levels clearly decreased at the 1th day (P< 0.001), 14th day (P = 0.007), and 28th day (P = 0.013). CONCLUSIONS: A clinically translational model of jaw ORN was successfully established and the application of α2M prior to radiation protected the bone from being injured by the radiation, possibly related to oxidative stress.

Constructing Environmental-Friendly "Oil-Diode" Janus Membrane for Oil/Water Separation.

Oil leakage is a global environmental issue and happens frequently, resulting in a waste of oil resources and even threatening the safety of marine creatures and humans. Because of unidirectional oil transportation performance, "oil-diode" Janus membranes have attracted lots of attention for oil/water separation. However, the hydrophobic side of traditional "oil-diode" Janus membrane is completely hydrophobic, resulting in an easy permeation of oil, which hampers light oil recycling. Herein, we provide a facile approach to develop "oil-diode" Janus membranes with the special wettable structure for fast oil refining. The material characteristics and surface wettability of the membranes that generate superimposed efforts are vital to fabricate "oil-diode" Janus membranes. Interestingly, the manufactured membranes exhibit extra-high oil intrusion pressure up to 12 kPa and present high permeance of about 2993 L m-2 h-1 bar-1 in separating stable water-in-oil emulsion containing surfactant and separation efficiency up to 99.6%, thereby showing promising potential in oil recovery and refining.

Effect of α2­macroglobulin in the early stage of jaw osteoradionecrosis.

Advanced osteoradionecrosis (ORN) is one of the most serious complications in patients with head and neck cancer, resulting in poor prognosis. Numerous studies have therefore focused on the pathogenesis and interventions of ORN early stage. The present study aimed to investigate whether α2­macroglobulin (α2M) could prevent early­stage jaw osteoradionecrosis caused by radiotherapy (RT). Following local injection of α2M, a single dose of 30 Gy was delivered to rats for pathological exploration. For 28 days, the irradiated mandible and soft tissues were examined for potential changes. Furthermore, primary human bone marrow mesenchymal stem cells pretreated with α2M followed by 8 Gy irradiation (IR) were also used. Tartrate­resistant acid phosphatase assay, terminal uridine deoxynucleotidyl nick end labeling assay and immunohistochemical staining were performed on irradiated mandibular bone, tongue or buccal mucosa tissues from rats. Cell proliferation was assessed by evaluating the cell morphology by microscopy and by using the cell counting kit­8. Fluorescence staining, flow cytometry and western blotting were conducted to detect the reactive oxygen species level, cell apoptosis and protein expression of superoxide dismutase 2 (SOD2), heme oxygenase­1 (HO­1) and phosphorylated Akt following irradiation. The results demonstrated that α2M attenuated physical inflammation, osteoclasts number and fat vacuole accumulation in mandibular bone marrow and bone marrow cell apoptosis following IR in vivo. Furthermore, α2M pretreatment suppressed the expression of 8­hydroxy­2'­deoxyguanosine in mandibular bone and tongue paraffin embedded sections, which is a marker of oxidative damage, and increased SOD2 expression in mucosa and tongue paraffin embedded sections. The present study demonstrated the efficient regulation of antioxidative enzymes, including SOD2 and heme oxygenase­1, and reduction in oxidative damage by α2M. In addition, in vitro results confirmed that α2M may protect cells from apoptosis and suppress reactive oxygen species accumulation. Overall, the present study demonstrated that α2M treatment may exert some radioprotective effects in early­stage ORN via antioxidant mechanisms, and may therefore be considered as a potential alternative molecule in clinical prophylactic treatments.

Protective effects of α­2­macroglobulin on human bone marrow mesenchymal stem cells in radiation injury.

Osteoradionecrosis of the jaws (ORNJ) is a complication of oral and maxillofacial malignancy that arises following radiotherapy; progressive jaw necrosis severely decreases the quality of life of patients. Human bone marrow mesenchymal stem cells (hBMMSCs) are a cell type with self­renewal and pluripotent differentiation potential in the bone marrow stroma. These cells are associated with bone tissue regeneration and are one of the primary cell types affected by bone tissue radiation injury. α­2­macroglobulin (α2M) is a glycoprotein­rich macromolecule that interacts with cytokines, growth factors and hormones to serve a variety of biological roles. In addition, α2M possesses radio­protective effects. The aim of the present study was to investigate whether α2M has protective effects against radiation injury of hBMMSCs. Cell counting kit­8 and colony formation assays were used to monitor cell proliferation. Western blot analysis and reverse transcription­quantitative polymerase chain reaction were used to detect Beclin1, microtubule­associated protein 1A/1B, sex determining region Y, Nanog, runt­related transcription factor 2, osteoglycin and manganese superoxide dismutase expression. The formation of calcium nodules was evaluated by Alizarin red staining after osteogenic induction. Flow cytometric analysis of Annexin­V and propidium iodide double staining was used to detect changes in apoptosis rate. Alkaline phosphatase and superoxide dismutase activity were determined using colorimetric assays. Reactive oxygen species levels were detected using 2',7'­dichlorodihydrofluorescein diacetate. The results of the present study revealed that α2M increased the rate of proliferation, reduced autophagy, alleviated pluripotent differentiation injury, increased the osteogenic differentiation ability and decreased the rate of apoptosis in hBMMSCs following irradiation via an antioxidative pathway. In conclusion, α2M exhibited protective effects against radiation injury in hBMMSCs and may be considered a potential therapeutic agent for the prevention and treatment of ORNJ.

[Progress in research of clinical applications of fascia lata allograft].

OBJECTIVE: To find out the recent progress in research of clinical application of fascia lata allograft. METHODS: The domestic and international articles were reviewed to summarize the principal properties, processing techniques, and various uses of fascia lata allograft. RESULTS: Histologically fascia lata is composed of parallel and compact bundles of collagen fibers with few cells and immunologically it is low-antigenic. After varied tissue processing and storage techniques, fascia lata, as the scaffold only with the extracellular matrix, has been used in clinical practice and achieved good results, such as ophthalmology, urology, and orthopaedics. CONCLUSION: Because of these unique properites in repairing defects and reconstructing functions, fascia lata allograft, as a natural biomaterial, is promising to be used in more aspects with the development of the biomedical techniques.

[Preparation of xenogeneic bone graft and its osteoinductivity].

OBJECTIVE: To develop a deantigenated porcine bone graft through enzyme treatment and to study the biomechanical properties and osteoinductivity of the xenogeneic bone graft. METHODS: Deantigenated xenogeneic bone was prepared from porcine bone by a series treatment including alpha-galactosidase (alpha-Gal) treatment, freeze drying and irradiation at a does of 25 kGy. Samples were divided into 4 groups according to the treatment methods: fresh bone (group A); deantigenated bone (group B); deantigenated and freeze dried bone (group C); deantigenated-freeze dried-irradiated bone (group D). SEM observation to group B samples was performed and the diameters of the caves of the porcine cancellous bone were measured. The a-Gal contents of samples of groups A, B, D were measured by ELISA. The effects of different treatments on porcine bone mechanic properties were evaluated through compressive test of 4 groups. The prepared porcine cortical bone were demineralized and ectopically implanted into muscle groups of hind limbs of Wistar rats as experimental group, and the demineralized cortical bone which were inactivated by high temperature and pressure were implanted as control group. Histological observation was performed and ALP activity was tested at different time postoperatively to investigate the osteoinductivity of the xenogeneic bone implants. RESULTS: The porous structure of prepared porcine cancellous bone was similar to that of human cancellous bone. The diameters of the caves were between 150-600 microm. The A value of the groups A, B, D was 0.358 +/- 0.027, 0.191 +/- 0.011, 0.191 +/- 0.009, respectively, with statistically differences between groups (P < 0.05). While the biomechanical properties among 4 groups had no statistically difference (P > 0.05). Histological observation showed mesenchymal cells immigrated into cartilage and converted into chondrocytes at 3 weeks postoperatively. Cartilage was formed at 4 weeks and osteoid and more adult cartilage was formed at 6 weeks within the implants of experimental group, while there was no bone formation in control group. ALP activity of experimental group at different times were obviously higher than that of the control group (P < 0.05). CONCLUSION: The main xenogeneic antigen of the porcine bone was removed while the mechanic properties and osteoinductivity remained, thus it may be a suitable bone substitute for clinical use.