Lack of bioactivity has seriously restricted the development of biodegradable implants for bone tissue engineering. Therefore, surface modification of the composite is crucial to improve the osteointegration for bone regeneration. Bone morphogenetic protein-2 (BMP-2), a key factor in inducing osteogenesis and promoting bone regeneration, has been widely used in various clinical therapeutic trials. In this study, BMP-2 was successfully immobilized on graphene oxide-incorporated PLGA/HA (GO-PLGA/HA) biodegradable microcarriers. Our study demonstrated that the graphene oxide (GO) facilitated the simple and highly efficient immobilization of peptides on PLGA/HA microcarriers within 120 min. To further test in vitro, MC3T3-E1 cells were cultured on different microcarriers to observe various cellular activities. It was found that GO and HA significantly enhanced cell adhesion and proliferation. More importantly, the immobilization of BMP-2 onto the GO-PLGA/HA microcarriers resulted in significantly greater osteogenic differentiation of cells in vitro, as indicated by the alkaline phosphate activity test, quantitative real-time polymerase chain reaction analysis, immunofluorescence staining and mineralization on the deposited substrates. Findings from this study revealed that the method to use GO-PLGA/HA microcarriers for immobilizing BMP-2 has a great potential for the enhancement of the osseointegration of bone implants.

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OBJECTIVESpontaneous paralysis from hourglass-like fascicular constriction of peripheral nerves is rare, its clinical manifestations are not well documented, and its pathogenesis remains unknown. The unclear origin of this disorder and difficulty in diagnosis result in its uncertain management. The authors sought to gain a more thorough understanding of this condition through describing the anatomy, clinical features, etiology, and treatment of hourglass-like constriction.METHODSThe authors retrospectively reviewed 20 patients (22 nerves) with hourglass-like constriction. The patients’ clinical information was reviewed. Preoperative sonographic assessment and electrophysiological examination of involved nerves were performed. Surgical treatments included interfascicular neurolysis and neurorrhaphy. Samples of tissue subjected to resected constriction were sent for pathological analysis. The patients had regular face-to-face follow-up visits.RESULTSAcute pain was always the first symptom and was followed by paralysis. Paralysis progression was rapid and serious. Surgical exploration indicated an hourglass-like constricted segment completely unrelated to the compressive structures. Electrophysiological analysis showed severe denervation, and histopathological examination showed inflammatory cell infiltration, demyelination, and reduction of nerve fibers.CONCLUSIONSHourglass-like fascicular constrictive neuropathy has an integrative effect from multiple different mechanisms. Surgical intervention is beneficial for selected patients who do not recover in a timely fashion and have hourglass-like lesions confirmed by preoperative ultrasound imaging. The authors recommend that early surgical intervention of the nerve be offered to patients who do not show any signs of recovery 3 months after onset. Both interfascicular neurolysis and neurorrhaphy are effective treatment methods. Mild to moderate constriction can usually be treated successfully by interfascicular neurolysis alone, whereas more advanced lesions with loss of fascicle continuity (severe constriction) may be best treated with resection and direct neurorrhaphy.

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Objective. To assess if the addition of fentanyl to brachial plexus block has an impact on anesthetic outcomes and complication rates in patients undergoing upper extremity surgeries. Methods. We explore the PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases for all randomized controlled trials (RCTs) comparing adjuvant fentanyl with placebo/no drug for patients undergoing upper extremity surgery under brachial plexus block. Outcomes assessed were onset, duration of sensory and motor anesthesia, complications, and postoperative analgesia scores. Meta-analysis was conducted utilizing a random-effects model. The risk of bias was assessed using the Cochrane Collaboration’s risk of bias assessment tool 2. Certainty of evidence was assessed using GRADE. Subgroup analysis was conducted depending upon the approach of brachial plexus block and type of local anesthetic. Results. Twelve RCTs with 660 patients were included. Addition of fentanyl had no effect on onset of sensory anesthesia (11 studies; MD: 0.48; 95% CI: −1.81, 0.85; I2 = 96%; p = 0.48 ) but significantly shortened onset of motor anesthesia (8 studies; MD: −2.36; 95% CI: −3.99, −0.74; I2 = 96%; p = 0.48 ). Duration of sensory anesthesia (9 studies; MD: 82.81; 95% CI: 41.81, 123.81; I2 = 99%; p < 0.0001 ) and motor anesthesia (7 studies; MD: 93.41; 95% CI: 42.35, 144.46; I2 = 99%; p = 0.0003 ) was significantly increased with addition of fentanyl. The certainty of evidence-based on GRADE was deemed to be moderate for both onset and duration of anesthesia. The incidence of overall complications (nausea/vomiting and pruritis) was significantly higher in the fentanyl group (7 studies; OR: 2.14; 95% CI: 1.04, 4.40; I2 = 8%; p = 0.04 ) but with low certainty of evidence. Conclusions. Adjuvant fentanyl with brachial plexus block improves the onset of motor anesthesia but not sensory anesthesia. The duration of both sensory and motor anesthesia is significantly prolonged with fentanyl by around 83–93 minutes. However, clinicians should be aware that complications such as nausea/vomiting and pruritis are increased twofold with the addition of the drug. Current evidence is limited risk of bias in the RCTs and high heterogeneity in the meta-analyses.