Improvement In Cranioplasty: Advanced Prosthesis Biomanufacturing

Additive manufacturing (AM) is a technology that enables the production of models and prosthesis directly from the 3D CAD model facilitating surgical procedures, implant quality and reducing risks. Furthermore, the additive manufacturing has been used to produce implants especially designed for a particular patient, with sizes, shapes and mechanical properties optimized, in many areas of medicine such as cranioplasty surgery. This work presents AM technologies applied to design and manufacture of a biomodel, in fact, an implant for the surgical reconstruction of a large cranial defect. A series of computed tomography data was obtained and software was used to extract the cranial geometry. The protocol presented was used for creation of anatomic biomodel of the bone defect for the surgical planning as well as to design and manufacture of the patient-specific implant, reducing duration of surgery besides improving the surgical accuracy due to preoperative planning of the anatomical details. (C) 2015 The Authors. Published by Elsevier B.V.492032082nd CIRP Conference on Biomanufacturing (CIRP-BioM)JUL 29-31, 2015Manchester, ENGLAN

EBSD-data analysis of an additive manufactured maraging 300 steel submitted to different tempering and aging treatments

This research was funded by FAPESP grants (2017/17697-5, 2019/00691-0, and 2020/09079-2) and was supported by LNNano – Brazilian Nanotechnology National Laboratory (CNPEM/MCTI) during the use of the electron microscopy open access facility. F. Conde acknowledges the Ph.D. scholarship CNPq 142440/2019-1. In addition, JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, of the Associate Laboratory Institute of Nanostructures, Nanomodelling, and Nanofabrication – i3N. Finally, Julian A. Avila is a Serra Hunter Fellow and a CNPq fellow. Publisher Copyright: © 2023 The AuthorsMaraging is a high alloy steel sensitive to the precipitation of intermetallics from a supersaturated solid solution during aging heat treatments. The precipitation phenomenon is well described in the literature, which gave rise to the alloy name regarding a martensite matrix with precipitates formed by aging treatment. Many studies have been performed to characterize this material, usually subjected to many sample preparations for transmission microscopy, which is very laborious, and few EBSD analyses. Therefore, in this work, a large study was conducted using electron backscatter diffraction (EBSD) to analyze maraging microstructures through band-contrast, kernel average misorientation (KAM), grain orientation spread (GOS), and misorientation distribution. Our results show that solubilization of the additive manufactured maraging steel resulted in a more homogeneous microstructure with new angle grain boundaries. Furthermore, tempering heat treatments relieve martensite strain, increasing band contrast values. Posterior aging presented a low impact on the results of EBSD analysis.publishersversionpublishe

Regenerative collagen biomembrane: Interim results of a Phase I veterinary clinical trial for skin repair [version 1; referees: 2 approved, 1 approved with reservations]

Background: The availability of commercial tissue engineering skin repair products for veterinary use is scarce or non-existent. To assess features of novel veterinary tissue engineered medical devices, it is therefore reasonable to compare with currently available human devices. During the development and regulatory approval phases, human medical devices that may have been identified as comparable to a novel veterinary device, may serve as predicate devices and accelerate approval in the veterinary domain. The purpose of the study was to evaluate safety and efficacy of the biomembrane for use in skin repair indications. Methods: In the study as a whole (3 year total length), 15 patients (animals), dogs and cats (male/female, 2 cm), with a wound depth equivalent to 2nd/3rd degree burns are to be studied from Day 0 to Day 120-240, post-application of the biomembrane. This interim report covers the 5 patients assessed to date and deemed eligible, of which 3 enrolled, and 2 have completed the treatment. Wound beds were prepared and acellular collagen biomembranes (Eva Scientific Ltd, São Paulo, Brazil) applied directly onto the wounds, and sutured at the margins to the patient's adjacent tissue. Wound size over time, healing rate, general skin quality and suppleness were assessed as outcomes. Qualitative (appearance and palpation) and quantitative (based on Image Analysis of photographs) wound assessment techniques were used. Results: Both patients’ wounds healed fully, with no adverse effects, and the healing rate was comparable in both, maxing out at approximately 1 cm2/day. Conclusions: Early results on the biomembrane's safety and efficacy indicate suitability for skin repair usage in veterinary patients

Austenite reversion kinetics and stability during tempering of an additively manufactured maraging 300 steel

FAPESP (2017/17697-5) FAPESP (2008/57863-0) FAPESP (2014/20844-1) FAPESP (2019/00691-0) CNPq (573661/2008-1) UID/EMS/00667/2019Reverted austenite is a metastable phase that can be used in maraging steels to increase ductility via transformation-induced plasticity or TRIP effect. In the present study, 18Ni maraging steel samples were built by selective laser melting, homogenized at 820 °C and then subjected to different isothermal tempering cycles aiming for martensite-to-austenite reversion. Thermodynamic simulations were used to estimate the inter-critical austenite + ferrite field and to interpret the results obtained after tempering. In-situ synchrotron X-ray diffraction was performed during the heating, soaking and cooling of the samples to characterize the martensite-to-austenite reversion kinetics and the reverted austenite stability upon cooling to room temperature. The reverted austenite size and distribution were measured by Electron Backscattered Diffraction. Results showed that the selected soaking temperatures of 610 °C and 650 °C promoted significant and gradual martensite-to-austenite reversion with high thermal stability. Tempering at 690 °C caused massive and complete austenitization, resulting in low austenite stability upon cooling due to compositional homogenization.publishe

Effect of thermal cycling and aging stages on the microstructure and bending strength of a selective laser melted 300-grade maraging steel

Additive manufacturing techniques allow the creation of complex parts in a layer by layer fashion, bringing new opportunities in terms of applications and properties when compared to conventional manufacturing processes. Among other ultra-high-strength steels, the 18 Ni maraging 300 steel offers a good toughness/strength ratio. However, when fabricated by additive manufacturing, this steel presents lower ductility and strain-hardening than its forging counterparts. One way to enhance ductility and toughness is to promote martensite-to-austenite reversion. Therefore, in the present study, 18 Ni maraging steel powder was processed by selective laser melting and different heat treatments were applied to the built parts, aiming for homogenization, microstructural refinement and martensite-to-austenite reversion. Thermodynamic simulations were used to assess a range of temperatures for the reversion heat treatments. Microstructural characterization was performed by scanning electron microscopy, electron backscattered diffraction and x-ray diffraction758192201CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP573661/2008-1não tem2017/17697-5; 2008/57863-0We would like to thank the Brazilian Nanotechnology National Laboratory and Brazilian Synchrotron Light Laboratory (LNLS) for the use of the SEM/EBSD and X-Ray Diffractometer, and the Gleeble 3S50™ thermo-mechanical simulator, respectively. FAPESP (2017/17697-5), FAPESP (2008/57863-0) and CNPq (573661/2008-1), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001, and the Portuguese foundation FCT - MCTES via UID/EMS/00667/2019 for their financial support. The chemical composition measurements were conducted at VILLARES METAL

CFD study of chemical vapor deposition reactor for synthesis of PHEMA

The current development of technologies related to materials for science, biology and medicine is gaining a new impetus in order to give a better treatment to injured tissues and organs. In this context, biomaterials and biofabrication techniques are providing a healthier life to the population. However, to produce implant parts and devices, there is the need for biocompatibility and absence of toxic materials, which may preclude their medical application. To avoid this situation, Chemical Vapor Deposition (CVD) is presented as an attractive technique, since it can produce, in some case solvent less, polymeric biomaterials and uniform adherent films over substrates in just one single processing step. The development of CVD reactors has been extensively studied, but little is known about their fluid dynamic behavior and associated heat and mass transfer effects. The aim of this paper was to simulate a CVD reactor during the synthesis of poly 2-hydroxyethyl methacrylate (PHEMA), through of the release of the gaseous 2-hydroxyethyl methacrylate (2-HEMA) and initiators in a single step, completely dry, without the use of solvents or volatiles. The impact of operating conditions in the quality and characteristics of the deposited material was explored. A computational fluid dynamic (CFD) study was carried out to simulate velocity and temperature distribution on the vertical CVD. As a result, certain design aspects related to heat and mass transfer were addressed, which allowed to understand and to suggest modifications in the reactor design. These simulations were important to define a desirable temperature operation range aiming a uniform flow distribution in the reactor4314591464FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação12th International Conference on Chemical and Process Engineering (ICheaP

Cranial reconstruction: 3D biomodel and custom-built implant created using additive manufacturing

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQAdditive manufacturing (AM) technology from engineering has helped to achieve several advances in the medical field, particularly as far as fabrication of implants is concerned. The use of AM has made it possible to carry out surgical planning and simulation using a three-dimensional physical model which accurately represents the patient's anatomy. AM technology enables the production of models and implants directly from a 3D virtual model, facilitating surgical procedures and reducing risks. Furthermore, AM has been used to produce implants designed for individual patients in areas of medicine such as craniomaxillofacial surgery, with optimal size, shape and mechanical properties. This work presents AM technologies which were applied to design and fabricate a biomodel and customized implant for the surgical reconstruction of a large cranial defect. A series of computed tomography data was obtained and software was used to extract the cranial geometry. The protocol presented was used to create an anatomic biomodel of the bone defect for surgical planning and, finally, the design and manufacture of the patient-specific implant.42818771884FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ2008/57860-32010/05321-1573661/2008-