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Among Additive Manufacturing (AM) technologies, Laser Powder Bed Fusion (LPBF) has made a great contribution to optimizing the production of customized implant materials. However, the design of the ideal surface topography, capable of exerting the best biological effect without drawbacks, is still a subject of study. The aim of the present study is to topographically and biologically characterize AM-produced Ti6Al4V ELI (Extra Low Interstitial) samples by comparing different surface finishing. Vertically and horizontally samples are realized by LPBF with four surface finishing conditions (as-built, corundum-sandblasted, zirconia-sandblasted, femtosecond laser textured). Bioactivity in vitro tests are performed with human osteoblasts evaluating morphology, metabolic activity, and differentiation capabilities in direct contact with surfaces. Scanning electron microscope and profilometry analysis are used to evaluate surface morphology and samples' roughness with and without cells. All tested surfaces show good biocompatibility. The influence of material surface features is evident in the early evaluation, with the most promising results of morphological study for laser texturing. Deposition orientations seem to influence metabolic activities, with XZ orientation more effective than XY. Current data provide the first positive feedback on the biocompatibility of laser texturing finishing, still poorly described in the literature, and support the future clinical development of devices produced with a combination of LPBF and different finishing treatments., (© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.)

Additively manufactured medical devices require proper surface finishing before their use to remove partially adhered particles and provide adequate surface roughness. The literature widely investigates regular lattice structures-mainly scaffolds with small pores to enhance osseointegration; however, only a few studies have addressed the impact of surface finishing on the dimensional deviation and the global and local mechanical responses of lattice samples. Therefore, the current research investigates the impact of biomedical surface finishing (i.e., corundum sandblasting and zirconia sandblasting) on Voronoi lattice structures produced by laser powder bed fusion (LPBF) with large pores and different thicknesses on the surface morphology and global and local mechanical behaviors. MicroCT and SEM are performed for the assessment of dimensional mismatch and surface evaluation. The mechanical properties are investigated with 2D digital image correlation (DIC) in quasi-static compression tests to estimate the impact of surface finishes on local maps of strain. In the quasi-static tests, both the global mechanical performances, as expected, and local 2D DIC strain maps were mainly affected by the strut thickness, and the impact of different surface finishings was irrelevant; on the contrary, different surface finishing processes led to differences in the dimensional deviation depending on the strut thickness. These results are relevant for designing lattice structures with thin struts that are integrated into medical prostheses that undergo AM.

Background and Objectives: Spring-assisted surgery is a popular option for the treatment of non-syndromic craniosynostosis. The main drawback of this procedure is the need for a second surgery for spring removal, which could be avoided if a distractor material could be metabolised over time. Iron-Manganese alloys (FeMn) have a good trade-off between degradation rate and strength; however, their biocompatibility is still debated. Materials and Methods: In this study, the neuro-compatibility of Fe-20Mn (wt.%) was assessed using standard assays. PC-12 cells were exposed to Fe-20Mn (wt.%) and stainless steel via indirect contact. To examine the cytotoxicity, a Cell Tox Green assay was carried out after 1, 2, and 3 days of incubation. Following differentiation, a neurite morphological examination after 1 and 7 days of incubation time was carried out. The degradation response in modified Hank's solution at 1, 3, and 7 days was investigated, too. Results: The cytotoxicity assay showed a higher toxicity of Fe-20Mn than stainless steel at earlier time points; however, at the latest time point, no differences were found. Neurite morphology was similar for cells exposed to Fe-20Mn and stainless steel. Conclusions: In conclusion, the Fe-20Mn alloy shows promising neuro-compatibility. Future studies will focus on in vivo studies to confirm the cellular response to Fe-20Mn.

Prosthetic reconstruction can serve as a feasible alternative, delivering both functional and aesthetic benefits to individuals with hand and finger injuries, frequent causes of emergency room visits. Implant-related infections pose significant challenges in arthroplasty and osteosynthesis procedures, contributing to surgical failures. As a potential solution to this challenge, this study developed a new class of silver (Ag)-doped chitosan (CS) coatings via electrophoretic deposition (EPD) on osseointegrated prostheses for infection therapy. These coatings were successfully applied to additively manufactured Ti 6 Al 4 V ELI samples. In the initial phase, the feasibility of the composite coating was assessed using the Thermogravimetric Analysis (TGA) and Attenuated Total Reflection (ATR) techniques. The optimized structures exhibited impressive water uptake in the range of 300-360%. Codeposition with an antibacterial agent proved effective, and scanning electron microscopy (SEM) was used to examine the coating morphology. Biologically, CS coatings demonstrated cytocompatibility when in direct contact with a fibroblast cell line (L929) after 72 h. When exposed to the Staphylococcus epidermidis strain (ATCC 12228), these coatings inhibited bacterial growth and biofilm formation within 24 h. These findings underscore the significant potential of this approach for various applications, including endoprostheses like hip implants, internal medical devices, and transcutaneous prostheses such as osseointegrated limb prosthetics for upper and lower extremities.

Thumb amputations leads to 50 % loss in hand functionality. To date, silicone vacuum prosthesis and autologous transplantation are the most adopted treatment solutions: nevertheless, vacuum prostheses lack in stability and cause skin issue and surgical treatment is not always accepted by patients. Osseointegrated implants were demonstrated to enhance stability, restore osseoperception and increase the time of prosthesis use. Thumb amputations present varying stump sizes: a standard size implant cannot address specificity of each patient, while a patient matched solution can meet surgeon requirements, by geometrical features of implant. The fixture presented in the current paper is the first additively manufactured patient matched osseointegrated implant for the treatment of thumb amputees. The current work aims to verify and validate a predictive finite element model (FEM) for mechanical strength of the presented fixture. FEM was demonstrated to correctly evaluate the mechanical strength of patient matched device. Minimum strength requirements were calculated in different core diameters: FEM were experimentally validated. Safety factor of 1.5 was guaranteed. Finally, considerations on performance of the prototype were carried out by means of insertion tests in Sawbones and axial pull-out force assessment. Cadaver tests to evaluate the entire procedure and production process are ongoing., Competing Interests: Declaration of competing Interest The authors declare no conflict of interest., (Copyright © 2023 IPEM. Published by Elsevier Ltd. All rights reserved.)

Background and Aims: Transcatheter aortic valve replacement (TAVR) is the mainstay of treatment of inoperable and severe high-risk aortic stenosis and is noninferior to surgical aortic valve replacement (SAVR) for low-risk and intermediate-risk patients as well. We aim to compare the valve size, area, and transaortic mean gradients in SAVR patients before and after the implementation of TAVR since being approved by the Food and Drug Administration  in 2011., Methods: Patients who underwent a bioprosthetic SAVR placement were divided into two groups based on the date of procedure: the early pre-TAVR implementation group (years 2011-2012) and the contemporary post-TAVR group (years 2019-2020). The primary endpoint was the mean gradient across the aortic valve within 16 months of surgery. The secondary endpoints included the difference in valve size and various aortic valve echocardiographic variables., Results: One hundred and thirty patients had their valves replaced in the years 2011-2012 and 134 in the years 2019-2020. The early group had a significantly higher mean gradient (median of 13 mmHg [interquartile range, IQR: 9.3-18] vs. 10 mmHg [IQR: 7.5-13.1], p  = 0.001) and a smaller median effective orifice area index (0.8 cm 2 /m 2 [IQR: 0.6-1] vs. 1.1 cm 2 /m 2 [IQR: 0.8-1.3], p  < 0.001). The median valve size was significantly smaller in the early group (median of 21 mm [IQR: 21-23] vs. 23 mm [IQR: 22.5-25], p  < 0.001)., Conclusion: In the contemporary era, surgical patients receive larger valves which translates into lower mean gradients, larger valve area, and lower rates of patient-prosthesis mismatch than in previous years before the routine introduction of TAVR., Competing Interests: The authors declare no conflicts of interest., (© 2022 The Authors. Health Science Reports published by Wiley Periodicals LLC.)

Sustainability has for long been promoted as a medium for social and economic development, one that focuses on constant availability of natural assets and ecological amenities. By questioning the possibility of reaching a balanced and sustainable state of functioning for social-ecological systems, resilience improves the static framework of sustainability by acknowledging non-linear behavior of complex systems, inevitability of change, and consistent presence of uncertainty. At the core of sustainable development, environmental policy is embedded in the socio-spatial structures that constantly re-organize and breed uncertainty, such as political, economic, and climate uncertainty. These uncertainties create episodes of instability that shock the entire system including the structures of environmental protection. In this article, focusing on the aftermath of 2016 US presidential election and 2018 general election in Brazil, both broadly recognized as political shocks, we highlight the vulnerabilities of environmental protection structures to the rise of conservative populist movements. We attribute these vulnerabilities, partially, to the superiority of market-based instruments, as well as apolitical understandings of resilience under neoliberalism that overlook political instabilities and socio-spatial outcomes of neoliberal restructuring projects. In our assessment, political unpreparedness of sustainability against the right-wing onslaught in the US and Brazil further underlines the need for resilience theory to incorporate sources of political instability in order to protect the environment., (© The Author(s) 2021.)

The present work explores the effect of a stress relieving heat treatment on the microstructure, tensile properties and residual stresses of the laser powder bed fused AlSi9Cu3 alloy. In fact, the rapid cooling rates together with subsequent heating/cooling cycles occurred during layer by layer additive manufacturing production make low temperature heat treatments desirable for promoting stress relaxation as well as limited grain growth: this combination can offer the opportunity of obtaining the best compromise between high strength, good elongation to failure and limited residual stresses. The microstructural features were analysed, revealing that the high cooling rate, induced by the process, caused a large supersaturation of the aluminum matrix and the refinement of the eutectic structure. Microhardness versus time curve, performed at 250 °C, allowed to identify a stabilization of the mechanical property at a duration of 25 h. The microstructure and the mechanical properties of the samples heat treated at 25 h and at 64 h, considered as a reference for the conventionally produced alloy, were compared with the ones of the as-built alloy. Finally, it was shown that a 59% reduction of the principal residual stresses could be achieved after the 25 h-long treatment and such evolution was correlated to the mechanical behaviour.

Purpose of Review: Sickle cell disease (SCD) is a hematological disorder which leads to serious complications in multiple organ systems. While significant research has addressed many of the effects of acute pain episodes and end-organ damage connected to this disease, little has approached the chronic pain state associated with this condition., Recent Findings: Associated chronic pain represents a significant detractor from the quality of life experienced by these patients, affecting over half of those with SCD on more days than not. Current treatment typically is centered upon preventing and responding to acute vasoocclusive crises, presumably because this is the most common reason for hospitalization in these patients. The lack of management of chronic pain symptoms leaves many with SCD in a state of suffering. In this review, the treatment methodologies of SCD patients are examined including alternative treatments, both pharmaceutical and non-pharmaceutical, as well as procedural approaches specifically aimed at reducing chronic pain in these patients.