Reparación quirúrgica de fracturas de fémur distal con biomodelos impresos 3D / Surgical repair of distal femur fractures with 3D printed biomodels

Introducción: Las fracturas complejas de fémur distal AO/AOT tipo 33C3.3 constituyen un reto para los ortopedistas debido a la dificultad de su tratamiento y las complicaciones asociadas. El planeamiento y procedimiento quirúrgicos emplean placas condilares, pero estas se asocian a la pérdida de la fijación y al colapso de la reducción. Objetivo: Describir la planificación preoperatoria de una fractura de fémur distal AO/AOT 33C3.3 con bioimpresión 3D y reconstrucción por computadora. Presentación del caso: Paciente masculino de 34 años con fractura izquierda conminuta del fémur distal, AO/AOT tipo 33C3.3, por un accidente de tránsito. El planeamiento y el tratamiento quirúrgicos se realizaron exitosamente con la impresión y reconstrucción de biomodelos 3D. Basados en las imágenes tomográficas del paciente, se identificaron los principales fragmentos, la secuencia de reducción, la cantidad y la posición de los implantes a utilizar. Conclusiones: La planificación preoperatoria resulta una etapa de vital importancia en el manejo de fracturas complejas. Las técnicas convencionales pueden optimizarse con la cirugía asistida por computadora y reconstrucción con biomodelos 3D impresos. Esta novedosa propuesta permitirá el adecuado uso de materiales, una óptima secuencia de reducción, mejor estabilidad de la fractura y menor riesgo de complicaciones quirúrgicas(AU)

Introduction: Complex distal femur fractures AO/AOT type 33C3.3 constitute a challenge for orthopedists due to the difficulty of their treatment and associated complications. The surgical planning and procedure use condylar plates; but these are associated with loss of fixation and collapse of the reduction. Objective: To describe preoperative planning for an AO/AOT 33C3.3 distal femur fracture with 3D bioprinting and computer reconstruction. Case report: The case of a 34-year-old male patient is reported. He has comminuted left fracture of the distal femur, AO/AOT type 33C3.3, due to a traffic accident. Surgical planning and treatment were successfully performed with 3D biomodel printing and reconstruction. Based on the patient's tomographic images, the main fragments, the reduction sequence, the number and position of the implants to be used were identified. Conclusions: Preoperative planning is a critically important stage in managing complex fractures. Conventional techniques can be optimized with computer-assisted surgery and reconstruction with 3D printed biomodels. This novel proposal will allow the appropriate use of materials, optimal reduction sequence, better stability of the fracture and lower risk of surgical complications(AU)

4D bioprinting technology and its application in cardiovascular tissue engineering / 生物工程学报

3D bioprinting technology is a rapidly developing technique that employs bioinks containing biological materials and living cells to construct biomedical products. However, 3D-printed tissues are static, while human tissues are in real-time dynamic states that can change in morphology and performance. To improve the compatibility between in vitro and in vivo environments, an in vitro tissue engineering technique that simulates this dynamic process is required. The concept of 4D printing, which combines "3D printing + time" provides a new approach to achieving this complex technique. 4D printing involves applying one or more smart materials that respond to stimuli, enabling them to change their shape, performance, and function under the corresponding stimulus to meet various needs. This article focuses on the latest research progress and potential application areas of 4D printing technology in the cardiovascular system, providing a theoretical and practical reference for the development of this technology.

Focus on periodontal engineering by 3D printing technology ­ a systematic review / Enfoque en la ingeniería periodontal mediante la tecnología de impresión 3D: una revisión sistemática

Three-dimensional (3D) bioprinting of cells is an emerging area of research but has not been explored yet in the context of periodontal tissue engineering. Objetive: This study reports on the optimization of the 3D bioprinting scaffolds and tissues used that could be applied clinically to seniors for the regenerative purpose to meet individual patient treatment needs. Material and Methods: We methodically explored the printability of various tissues (dentin pulp stem/progenitor cells, periodontal ligament stem/progenitor cells, alveolar bone stem/progenitor cells, advanced platelet-rich fibrin and injected platelet-rich fibrin) and scaffolds using 3D printers pertaining only to periodontal defects. The influence of different printing parameters with the help of scaffold to promote periodontal regeneration and to replace the lost structure has been evaluated. Results: This systematic evaluation enabled the selection of the most suited printing conditions for achieving high printing resolution, dimensional stability, and cell viability for 3D bioprinting of periodontal ligament cells. Conclusion: The optimized bioprinting system is the first step towards the reproducible manufacturing of cell laden, space maintaining scaffolds for the treatment of periodontal lesions.

La bioimpresión tridimensional (3D) de células es un área emergente de investigación, pero aún no se ha explorado en el contexto de la ingeniería de tejidos periodontales. Objetivo: Este estudio informa sobre la optimización de los tejidos y andamios de bioimpresión 3D utilizados que podrían aplicarse a personas mayores en el entorno clínico con fines regenerativos para satisfacer las necesidades de tratamiento de cada paciente. Material y Métodos: Exploramos metódicamente la capacidad de impresión de varios tejidos (células madre / progenitoras de la pulpa de dentina, células madre / progenitoras del ligamento periodontal, células madre / progenitoras de hueso alveolar, fibrina rica en plaquetas avanzada y fibrina rica en plaquetas inyectada) y andamios utilizando impresoras 3D que pertenecen solo a defectos periodontales. Se ha evaluado la influencia de diferentes parámetros de impresión con la ayuda de andamios para promover la regeneración periodontal y reemplazar la estructura perdida. Resultados: Esta evaluación sistemática permitió la selección de las condiciones de impresión más adecuadas para lograr una alta resolución de impresión, estabilidad dimensional y viabilidad celular para la bioimpresión 3D de células del ligamento periodontal. Conclusión: El sistema de bioimpresión optimizado es el primer paso hacia la fabricación reproducible de andamios de mantenimiento de espacio cargados de células para el tratamiento de lesiones periodontales

Uso de digitalizador e impressora doméstica em 3 dimensões em rinoplastia / Domestic three-dimensional scanner and printer in patients undergoing rhinoplasty

Os princípios para uma rinoplastia bem-sucedida incluem consulta e planejamento pré-operatório e uma análise clínica abrangente que defina as metas da cirurgia. Mais recentemente, a digitalização e a impressão doméstica em 3 dimensões tornaram-se disponíveis. O objetivo deste estudo é descrever um método de digitalização em 3 dimensões e de impressão doméstica da anatomia real do paciente para ser usada como ajuda intraoperatória. Nós apresentamos uma forma de uso desta tecnologia no transoperatório, auxiliando o cirurgião a comparar os resultados obtidos após suas manobras, verificar a sua adesão ao plano cirúrgico previamente estabelecido e melhorar a sua tomada de decisão durante a cirurgia. Em conclusão, a aplicação da impressão doméstica em 3 dimensões demonstra um efeito positivo sobre o tratamento de alterações estéticas do nariz.

The principles for a successful rhinoplasty include preoperative consultation and planning, as well as a comprehensive clinical analysis and defining rhinoplasty goals. Three-dimensional domestic scanning and printing have recently become available. We sought to objectively describe this method as an intraoperative aid in patients' anatomy. This method can be used trans-operatively to help surgeons compare the results of his or her technique, check adherence to the surgical plan, and improve his or her surgical decision-making. We found that the application of 3-dimensional printing had a positive effect on the treatment of patients with aesthetic nose disorders.

Optimization and comparison of two different 3D culture methods to prepare cell aggregates as a bioink for organ printing

The ultimate goal of tissue engineering is to design and fabricate functional human tissues that are similar to natural cells and are capable of regeneration. Preparation of cell aggregates is one of the important steps in 3D tissue engineering technology, particularly in organ printing. Two simple methods, hanging drop (HD) and conical tube (CT) were utilized to prepare cell aggregates. The size and viability of the aggregates obtained at different initial cell densities and pre-culture duration were compared. The proliferative ability of the cell aggregates and their ability to spread in culture plates were also investigated. In both methods, the optimum average size of the aggregates was less than 500 µm. CT aggregates were smaller than HD aggregates. 5,000 cells per drop HD aggregates showed a marked ability to attach and spread on the culture surface. The proliferative ability reduced when the initial cell density was increased. Comparing these methods, we found that the HD method having better size controlling ability as well as enhanced ability to maintain higher rates of viability, spreading, and proliferation. In conclusion, smaller HD aggregates might be a suitable choice as building blocks for making bioink particles in bioprinting technique.