Clinical Applications of Additive Manufacturing Models in Neurosurgery: a Systematic Review

Introduction Three-dimensional (3D) printing technologies provide a practical and anatomical way to reproduce precise tailored-made models of the patients and of the diseases. Those models can allow surgical planning, besides training and surgical simulation in the treatment of neurosurgical diseases. Objective The aim of the present article is to review the scenario of the development of different types of available 3D printing technologies, the processes involved in the creation of biomodels, and the application of those advances in the neurosurgical field. Methods We searched for papers that addressed the clinical application of 3D printing in neurosurgery on the PubMed, Ebsco, Web of Science, Scopus, and Science Direct databases. All papers related to the use of any additivemanufacturing technique were included in the present study. Results Studies involving 3D printing in neurosurgery are concentrated on threemain areas: (1) creation of anatomical tailored-made models for planning and training; (2) development of devices and materials for the treatment of neurosurgical diseases, and (3) biological implants for tissues engineering. Biomodels are extremely useful in several branches of neurosurgery, and their use in spinal, cerebrovascular, endovascular, neuro-oncological, neuropediatric, and functional surgeries can be highlighted. Conclusions Three-dimensional printing technologies are an exclusive way for direct replication of specific pathologies of the patient. It can identify the anatomical variation and provide a way for rapid construction of training models, allowing the medical resident and the experienced neurosurgeon to practice the surgical steps before the operation.

From the past to the future of therapeutic orthoses for upper limbs rehabilitation

Abstract Introduction The expansion of assistive technologies has been increasing significantly, involving almost all the daily activities, performed by disabled people. One of the highlights to be mentioned is the robotic orthoses, which are being used to amplify movements, to replace amputated limbs, and for a variety of rehabilitation therapies, among others. This study aims to present a review about upper limbs' orthoses, discussing their weaknesses, potentialities, and pointing out for future perspectives under the motor rehabilitation. Methods For this research, it had been identified 161 papers, based on the bibliographic bases from IEEE and Science Direct, which were filtered by the keywords orthoses, hand, upper-limbs and technology. After the appropriate exclusions, 22 papers were analyzed. Results This review indicates that most of the orthoses have been developed for rehabilitation therapies to be employed by people who have suffered stroke, cerebral palsy or spinal cord injury. This research summarized that the upper limbs movements are effectively produced by electric or pneumatic actuators, having a variety of degrees of freedom. Conclusion This review has shown that, although there are many orthoses styles, ranging from electric to pneumatic actuators; also there are some technical restrictions that prevent their use by most people. However, upper limb orthoses seem to be a great solution for the rehabilitation of people who have suffered a stroke.

Proliferation and differentiation of stem cells in contact with eluate from fibrin-rich plasma membrane / Proliferação e diferenciação de células-tronco em contato com eluato de membrana de fibrina

ABSTRACT Objective: To evaluate the ability of the eluate from fibrin-rich plasma (FRP) membrane to induce proliferation and differentiation of isolated human adipose-derived stem cells (ASCs) into chondrocytes. Method: FRP membranes were obtained by centrifugation of peripheral blood from two healthy donors, cut, and maintained in culture plate wells for 48 h to prepare the fibrin eluate. The SCATh were isolated from adipose tissue by collagenase digestion solution, and expanded in vitro. Cells were expanded and treated with DMEM-F12 culture, a commercial media for chondrogenic differentiation, and eluate from FRP membrane for three days, and labeled with BrdU for quantitative assessment of cell proliferation using the High-Content Operetta® imaging system. For the chondrogenic differentiation assay, the SCATh were grown in micromass for 21 days and stained with toluidine blue and aggrecan for qualitative evaluation by light microscopy. The statistical analysis was performed using ANOVA and Tukey's test. Results: There was a greater proliferation of cells treated with the eluate from FRP membrane compared to the other two treatments, where the ANOVA test showed significance (p < 0.001). The differentiation into chondrocytes was visualized by the presence of mucopolysaccharide in the matrix of the cells marked in blue toluidine and aggrecan. Conclusions: Treatment with eluate from FRP membrane stimulated cell proliferation and induced differentiation of the stem cells into chondrocytes, suggesting a potential application of FRP membranes in hyaline cartilage regeneration therapies.

RESUMO Objetivo: Avaliar a capacidade do eluato proveniente da membrana de plasma rico em fibrina (PRF) de induzir proliferação e diferenciação das células-tronco humanas isoladas de tecido adiposo (CTDAh) em condrócitos. Método: As membranas de PRF foram obtidas por centrifugação de sangue periférico de dois indivíduos saudáveis, cortadas, colocadas em poços de placa de cultivo por 48 h para obtenção do eluato de fibrina. As CTDAh foram isoladas do tecido adiposo por digestão com solução de colagenase e expandidas in vitro. As células foram expandidas e tratadas com meio de cultivo DMEM-F12, meio comercial para diferenciação condrocítica, e eluato de fibrina durante três dias e marcadas com BrdU para avaliação quantitativa da proliferação celular com o uso do sistema de imagens High-Content Operetta®. Para o ensaio de diferenciação condrogênica, as CTDAh foram cultivadas em micromassa por 21 dias e coradas com azul de toluidina e agrecana para avaliação qualitativa em microscópio óptico. As avaliações estatísticas foram feitas por meio dos testes Anova e Tukey. Resultados: Houve uma maior proliferação das células tratadas com o eluato de fibrina comparativamente com os outros dois tratamentos, nos quais o teste Anova apontou significância (p < 0,001). A diferenciação em condrócitos foi visualizada pela presença de mucopolissacarídeos na matriz das células tratadas com meio de diferenciação ou eluato e marcação positiva para agrecana. Conclusões: O tratamento com o eluato da membrana de fibrina estimulou a proliferação celular e induziu a diferenciação das células-tronco em condrócitos, o que sugere uma potencial aplicação da membrana de PRF nas terapias de regeneração de cartilagem hialina.

Biocompatible glassceramic applied in drug release system / Vitrocerâmico biocompatível aplicado em sistemas de liberação de medicamentos

A anortita é um material inteligente que se degrada apenas em meio ácido. Este comportamento, juntamente com a sua biocompatibilidade, é interessante para aplicações clínicas onde a degradação do biomaterial é desejável, como em sistemas de liberação de medicamentos. O objetivo deste trabalho é avaliar a aplicabilidade das cápsulas de anortita como sistemas de liberação de medicamentos,usando L-Dopa mais benserazida como medicamento de teste. Cápsulas esféricas foram confeccionadas, pesadas, preenchidas com o medicamento, seladas e imersas em solução tampão com pH = 3,5 durante 120 horas, mantida em movimento constante para simular o ambiente corpóreo. No final do ensaio as cápsulas foram esvaziadas, lavadas, secas e pesadas novamente. A perda de massa média foi de 0,004 mais ou menos 0,001 g, demonstrando a degradação do vitrocerâmico em meio ácido. Um espectrofotômetro UV/VIS foi usado para medir a quantidade de medicamento liberada na solução, através de amostras coletadas em períodos de 24, 72 e 120 horas após o início do ensaio. O medicamento foi detectado na solução após 24 horas, com concentração crescente até 72 horas, quando a taxa de liberação do medicamento pareceu diminuir. Através das amostrasanalisadas, foi possível concluir que ocorreu uma liberação contínua do medicamento através das paredes das cápsulas devido à sua porosidade. Os resultados mostraram a possibilidade de utilização da anortita em sistemas de liberação de medicamentos mantendo a liberação contínua da droga no organismo.

The anorthite is an intelligent material which degrades only in acid medium. this behavior along with its biocompatibility is interesting for clinical applications where degradation of a biomaterial is desired, such as in a drug delivery systems. The aim os this work is the assessment of the application of anorthite capsules as drug delivery system...