Aluminum Nanoparticles Affect Human Platelet Function In Vitro

Endoprostheses are prone to tribological wear and biological processes that lead to the release of particles, including aluminum nanoparticles (Al NPs). Those particles can diffuse into circulation. However, the toxic effects of NPs on platelets have not been comprehensively analyzed. The aim of our work was to investigate the impact of Al NPs on human platelet function using a novel quartz crystal microbalance with dissipation (QCM-D) methodology. Moreover, a suite of assays, including light transmission aggregometry, flow cytometry, optical microscopy and transmission electron microscopy, were utilized. All Al NPs caused a significant increase in dissipation (D) and frequency (F), indicating platelet aggregation even at the lowest tested concentration (0.5 µg/mL), except for the largest (80 nm) Al NPs. A size-dependent effect on platelet aggregation was observed for the 5–20 nm NPs and the 30–50 nm NPs, with the larger Al NPs causing smaller increases in D and F; however, this was not observed for the 20–30 nm NPs. In conclusion, our study showed that small (5–50 nm) Al NPs caused platelet aggregation, and larger (80 nm) caused a bridging–penetrating effect in entering platelets, resulting in the formation of heterologous platelet–Al NPs structures. Therefore, physicians should consider monitoring NP serum levels and platelet activation indices in patients with orthopedic implants

Aluminum Nanoparticles Affect Human Platelet Function In Vitro

Endoprostheses are prone to tribological wear and biological processes that lead to the release of particles, including aluminum nanoparticles (Al NPs). Those particles can diffuse into circulation. However, the toxic effects of NPs on platelets have not been comprehensively analyzed. The aim of our work was to investigate the impact of Al NPs on human platelet function using a novel quartz crystal microbalance with dissipation (QCM-D) methodology. Moreover, a suite of assays, including light transmission aggregometry, flow cytometry, optical microscopy and transmission electron microscopy, were utilized. All Al NPs caused a significant increase in dissipation (D) and frequency (F), indicating platelet aggregation even at the lowest tested concentration (0.5 µg/mL), except for the largest (80 nm) Al NPs. A size-dependent effect on platelet aggregation was observed for the 5–20 nm NPs and the 30–50 nm NPs, with the larger Al NPs causing smaller increases in D and F; however, this was not observed for the 20–30 nm NPs. In conclusion, our study showed that small (5–50 nm) Al NPs caused platelet aggregation, and larger (80 nm) caused a bridging–penetrating effect in entering platelets, resulting in the formation of heterologous platelet–Al NPs structures. Therefore, physicians should consider monitoring NP serum levels and platelet activation indices in patients with orthopedic implants

The outcome of primary per oral endoscopic myotomy (POEM) for treatment of achalasia: Norwegian single-center experience with long-term follow-up

Background and aims: Per oral endoscopic myotomy (POEM) has become an established treatment for achalasia, but no Scandinavian studies with long-term follow-up exist. This study from a tertiary referral center in Norway investigates the short-, mid-, and long-term feasibility, safety, efficacy, and complications of POEM. Methods: Prospective data from the first 84 patients who underwent POEM from 2014 to 2019 were analyzed. The median follow-up time was 44 months. Clinical success was defined as the Eckardt score (ES) ⩽3, and reflux as pathological if the acid exposure time (pH < 4) was more than 6%. ES was used for symptom evaluation before, and at 6, 12, and up to 64 months after POEM. Results: A total of 50 males and 34 females were included. A total of 43 (51%) were treatment naïve, 24 (28.6%) had been previously treated with botulinum toxin, pneumatic balloon dilatation, or both, and 17 (20.2%) were previously treated with Heller’s myotomy. The median post-POEM ES at 12 months was 1 (0–9), compared to pre-POEM 7 (4–12) (p < 0.01). At 12 months after POEM, clinical success persisted in 74 patients (88.1%). Clinical success was the highest for patients who were naïve to treatment, 41/43 (95%), and lower for those previously treated with Heller’s myotomy 12/17 (70.6%). Long-term follow-up at 5–6 years of 42 patients showed a clinical success rate of 94%. We experienced adverse events in five patients (6%). Post-POEM pathological reflux was found in 46% (28/61). After 3–4 years, the median ES was 1, and after 5–6 years, it was 2. Conclusion: POEM was safe and relieved the symptoms of achalasia significantly and persistently. The procedure had a better outcome in treatment naïve than previously treated patients. However, POEM is associated with significantly increased esophageal acid exposure.publishedVersio