Antimicrobial and Pro-Osteogenic Coaxially Electrospun Magnesium Oxide Nanoparticles-Polycaprolactone /Parathyroid Hormone-Polycaprolactone Composite Barrier Membrane for Guided Bone Regeneration.

Introduction: An antibacterial and pro-osteogenic coaxially electrospun nanofiber guided bone regeneration (GBR) membrane was fabricated to satisfy the complicated and phased requirements of GBR process. Methods: In this study, we synthesize dual-functional coaxially electrospun nanofiber GBR membranes by encapsulating parathyroid hormone (PTH) in the core layer and magnesium oxide nanoparticles (MgONPs) in the shell layer (MgONPs-PCL/PTH-PCL). Herein, the physicochemical characterization of MgONPs-PCL/PTH-PCL, the release rates of MgONPs and PTH, and antibacterial efficiency of the new membrane were evaluated. Furthermore, the pro-osteogenicity of the membranes was assessed both in-vitro and in-vivo. Results: We successfully fabricated a coaxially electrospun nanofiber MgONPs-PCL/PTH-PCL membrane with the majority of nanofibers (>65%) ranged from 0.40~0.60µm in diameter. MgONPs-PCL/PTH-PCL showed outstanding antibacterial potential against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through the release of MgONPs. We also discovered that the incorporation of MgONPs significantly prolonged the release of PTH. Furthermore, both the in-vivo and in-vitro studies demonstrated that high dosage of PTH promoted pro-osteogenicity of the membrane to improve bone regeneration efficacy with the presence of MgONPs. Conclusion: The new composite membrane is a promising approach to enhance bone regeneration in periodontitis or peri-implantitis patients with large-volume bone defects.

What is a meaningful pain reduction in patients with complex regional pain syndrome type 1?

OBJECTIVE: To investigate the degree of pain reduction in patients with complex regional pain syndrome type 1 (CRPS 1) that can be defined as "successful." DESIGN: All patients rated their pain on a visual analog scale (VAS; 0-10) before treatment and on three occasions after treatment, at 6 months, 1 year, and 2 years. Patients also rated a Global Perceived Effect (GPE) for their pain relief at the same time periods. The GPE items were classified as "successful" or "unsuccessful." The mean absolute and relative pain reduction (using the VAS) was calculated for both "successful" and "unsuccessful" GPE classifications for each time period. Sensitivity and specificity analyses were performed. PATIENTS: Sixty-one patients with CRPS 1. RESULTS: The patients defined a relative pain reduction of 58% (SD, 23.4) or more as "successful," whereas in "successful" and "unsuccessful" patient groups the pain was reduced significantly on the VAS. Furthermore, sensitivity and specificity analyses showed that a cut-off point of 50% relative pain reduction and a 3-cm absolute pain reduction on the VAS have the highest likelihood that patients will report their treatment "successful" on the GPE. CONCLUSIONS: Relative pain reduction of 50% or more and an absolute pain reduction of at least 3 cm on the VAS are accurate in predicting a successful pain reduction after a given treatment.