Effect of Hydrothermal (Sr)-Hydroxyapatite Coatings on the Corrosion Resistance and Mg2+ Ion Release to Enhance Osteoblastic Cell Responses of AZ91D Alloy.

The biomedical applications of Mg-based alloys are limited by their rapid corrosion rate in the body fluid. In this study, the hydrothermal synthesis is employed to produce protective bioactive hydroxyapatite coating (HAC) and strontium-substituted hydroxyapatite coating (Sr-HAC) to further enhance the corrosion resistance and in vitro biocompatibility of biodegradable AZ91D Mg alloy in physiological environments. For comparison, the brucite Mg(OH)2 prepared by the alkaline pre-treatment is designated as a control group. Experimental evidences of XRD and XPS analysis confirm that Sr2+ ions can be incorporated into HA crystal structure. It is noted that the hydrothermally synthesized Sr-HAC conversion coating composed of a specific surface topography with the nanoscaled flake-like fine crystallites is constructed on the AZ91D Mg alloy. The hydrophilicity of Mg substrate is effectively enhanced with the decrease in static contact angles after performing alkaline and hydrothermal treatments. Potentiodynamic polarization measurements reveal that the nanostructured Sr-HAC-coated specimens exhibit superior corrosion resistance than HAC and alkaline pre-treated Mg(OH)2. Moreover, immersion tests demonstrate that Sr-HAC provides favorable long-term stability for the Mg alloy with decreasing concentration of released Mg2+ ions in the SBF and the reduced corrosion rate during the immersion length of 30 days. The cells cultured on Sr-HAC specimens exhibit higher viability than those on the alkaline-pre-treated Mg(OH)2 and HAC specimens. The Sr-substituted HA coating with a nanostructured surface topography can help to stimulate the cell viability of osteoblastic cells.

Effectiveness of electroacupuncture (EA) for the treatment of urinary incontinence (UI) in patients with spinal cord injury (SCI): A protocol of systematic review of randomized controlled trials.

BACKGROUND: The objective of this study is to examine the effectiveness and safety of electroacupuncture (EA) in the treatment of urinary incontinence (UI) in patients with spinal cord injury (SCI). METHODS: All potential studies will be retrieved from the electronic databases of MEDLINE, EMBASE, Cochrane Library, PsycINFO, Web of Science, CBM, and China National Knowledge Infrastructure from origin of each database up to January 31, 2020. Additionally, we will check other resources, such as Google scholar, dissertations, conference proceedings, and reference lists of included studies. No language and publication date limitations will be considered in the literature resources search. All randomized controlled trials using EA for the treatment of UI in patients with SCI will be included. Two independent investigators will perform study selection, data extraction and study quality assessment. If any conflicts occur, we will invite a third investigator to solve them. Cochrane risk of bias will be used for study quality assessment, and RevMan 5.3 software will be employed for statistical analysis. RESULTS: This study will summarize the most recent evidence to assess the effectiveness and safety of EA for the treatment of UI in patients with SCI. CONCLUSION: The results of this study will provide helpful evidence to determine whether EA is effective and safety for the treatment of UI in patients with SCI or not. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42020165562.

Neuromuscular electrical stimulation for cancer pain in children with osteosarcoma: A protocol of systematic review.

BACKGROUND: This systematic review will assess the effectiveness and safety neuromuscular electrical stimulation (NMES) for cancer pain (CP) in children with osteosarcoma. METHODS: This systematic review protocol will retrieve the following electronic databases from inception to June 1 in Cochrane Library, MEDLINE, EMBASE, Web of Science, Scopus, CNKI, and VIP database. Manual head-searching of reference lists and conference proceedings will be performed to further examine the articles of interest. No restrictions will be applied to language and publication status. We will utilize a 3-stage approach to scan titles, abstracts, and full-text studies against all eligibility criteria, and collect data from included trials. Study quality will be evaluated by the Cochrane Risk of Bias Tool. If possible, we will narratively summarize study results and carry out meta-analysis. RESULTS: This study will recapitulate the present high quality trials to appraise the effectiveness and safety of NMES for CP in children with osteosarcoma. CONCLUSION: The findings of this study will present evidence to determine whether NMES is effective and safe for CP in children with osteosarcoma.