The use of biomaterials in medicine is not recent, and in the last few decades, the research and development of biocompatible materials had emerged. Hydroxyapatite (HAp), a calcium phosphate that constitutes a large part of the inorganic composition of human bones and teeth, has been used as an interesting bioceramic material. Among its applications, HAp has been used to carry antitumor drugs, such as doxorubicin, cisplatin, and gemcitabine. Such HAp-based composites have an essential role in anticancer drug delivery systems, including the treatment of osteosarcoma. In addition, the association of this bioceramic with magnetic nanoparticles (MNPs) has also been used as an effective agent of local magnetic hyperthermia. Further, the combined approach of the aforementioned techniques (HAp scaffolds combined with anti-tumor drugs and MNPs) is also an attractive therapeutical alternative. Considering the promising role of the use of bioceramics in modern medicine, we proposed this review, presenting an updated perspective on the use of HAp in the treatment of cancer, especially osteosarcoma. Finally, after giving the current progress in this field, we highlight the urgent need for efforts to provide a better understanding of their potential applications.

Peristaltic pumps are used in healthcare for their ability to aseptically displace various fluids, including medium-density gels and suspended solids. However, they have the undesirable characteristic of pulsing at their output. Three-dimensional printing is becoming a reality in tissue engineering, and it generally uses syringes to extrude hydrogels. One of the problems to be solved is the microdosing of biomaterials or bioinks when it is necessary to print large volumes. The use of peristaltic pumps in bioprinting is desirable as it does not limit the volume to the contents of a syringe while achieving dosage control. A peristaltic pump was designed and implemented to avoid pulsation errors and microliter dosing while allowing a large amount of fluid displacement. Two pumps with equal displacement were built. The first uses the conventional profile and is the baseline for comparisons, while the second presents the profile studied and proposed. The concepts demonstrated by Bernoulli were used, fixing the height of a column of water, while the two pumps provide flow to the system asynchronously, allowing the reading of pressure as a function of the speed variation created by the pulsation of each pump. An approximately 100 times reduction in pulsation was observed during fluid displacement with the variance reduced from 2.64 to 0.025 s 2 . The two pumps were also installed on a modified Ultimaker FDM 3D printer, and a standard for comparison was printed using a water-based hydrogel, corn starch, and corn-derived triglyceride, showing that the proposed pump improves the deposition quality of the material. Three-dimensional prints, tubes 20 mm in diameter by 8 mm in height and 0.7 mm in wall width, were also produced. Videos obtained show that the first pump was not able to print more than 4 mm in height, while the second prints the model with high quality and without deficiency. The results show that the new pump profile is able to provide a sufficiently constant volume for three-dimensional printing with excellent deposition control, building a simple object but difficult to obtain for a common peristaltic pump.

Introduction: 3D object printing technology is a resource increasingly used in medicine in recent years, mainly incorporated in surgical areas like orthopedics. The models made by 3D printing technology provide surgeons with an accurate analysis of complex anatomical structures, allowing the planning, training, and surgery simulation. In orthopedic surgery, this technique is especially applied in oncological surgeries, bone, and joint reconstructions, and orthopedic trauma surgeries. In these cases, it is possible to prototype anatomical models for surgical planning, simulating, and training, besides printing of instruments and implants. Purpose: The purpose of this paper is to describe the acquisition and processing from computed tomography images for 3D printing, to describe modeling and the 3D printing process of the biomodels in real size. This paper highlights 3D printing with the applicability of the 3D biomodels in orthopedic surgeries and shows some examples of surgical planning in orthopedic trauma surgery. Patients and Methods: Four examples were selected to demonstrate the workflow and rationale throughout the process of planning and printing 3D models to be used in a variety of situations in orthopedic trauma surgeries. In all cases, the use of 3D modeling has impacted and improved the final treatment strategy. Conclusion:The use of the virtual anatomical model and the 3D printed anatomical model with the additive manufacturing technology proved to be effective and useful in planning and performing the surgical treatment of complex articular fractures, allowing surgical planning both virtual and with the 3D printed anatomical model, besides being useful during the surgical time as a navigation instrument.

The use of bio-materials in medicine has intensified as new treatments are emerging. Among bio-materials, bio-ceramics have attracted attention due to their applications in regeneration, generation and formation of bone tissues. Calcium phosphates, more specifically hydroxyapatite, make up a large part of the composition of human bones and teeth. The bio-material is used mainly for the production of porous scaffolds to act as a bone graft. This work reviews techniques currently used for manufacturing scaffolds, and studies parameters of a technique called direct foaming to try to adapt the process for the production of hydroxyapatite scaffolds. Suspensions were produced with the aid of mechanical stirrer and ultrasonic stirrer to compare the dispersion produced. Results show the need to improve freeze casting techniques for biomedical applications. It was observed that 3D printing to produce scaffolds is adequate but can be optimized. The direct foaming method generated promising scaffolds, and it is possible to adapt the process to make parts of hydroxyapatite.

Resumo Objetivo Avaliar uma proposta de processo de impressão tridimensional (3D) de um biomodelo preparado com o auxílio da tecnologia de modelagem por deposição de material fundido (fused deposition modeling, FDM, em inglês) a partir de imagens de tomografia computadorizada (TC) de um indivíduo com pseudartrose de fratura coronal do côndilo femoral (fratura de Hoffa). Materiais e Métodos Para tanto, utilizamos imagens de TC, que permitem estudar a reconstrução volumétrica 3D do modelo anatômico, além da arquitetura e geometria óssea de sítios de anatomia complexa, como as articulações. Também permite o planejamento cirúrgico virtual (PCV) em um programa de desenho assistido por computador (computer-aided design, CAD, em inglês). Essa tecnologia possibilita a impressão de modelos anatômicos em escala real que podem ser utilizados em simulações cirúrgicas para o treinamento e a escolha do melhor posicionamento do implante de acordo com o PCV. Na avaliação radiográfica da osteossíntese da pseudartrose de Hoffa, verificou-se a posição do implante no modelo anatômico impresso em 3D e no joelho do paciente. Resultados O modelo anatômico impresso em 3D apresentou características geométricas e morfológicas semelhantes às do osso real. O posicionamento dos implantes em relação à linha de pseudartrose e pontos anatômicos foram bastante precisos na comparação do joelho do paciente com o modelo anatômico impresso em 3D. Conclusão A utilização do modelo anatômico virtual e do modelo anatômico impresso em 3D com a tecnologia de manufatura aditiva (MA) foi eficaz e auxiliou o planejamento e a realização do tratamento cirúrgico da pseudartrose da fratura de Hoffa. Desta forma, foi bastante preciso na reprodutibilidade do planejamento cirúrgico tanto virtual quanto no modelo anatômico impresso em 3D.