Bone presents an intrinsic ability for self-regeneration and repair, however critical defects and large fractures require invasive and time-consuming clinical interventions. As an alternative to current therapy, bone tissue engineering (BTE) has primarily aimed to recreate the bone microenvironment by delivering key biomolecules and/or by modification of scaffolds to guide cell fate towards the osteogenic lineage or other phenotypes that may benefit the bone regeneration mechanism. Considering that bone cells communicate, in their native microenvironment, through biochemical and physical signals, most strategies fail when considering only chemical, geometrical or mechanical cues. This is not representative of the physiological conditions, where the cells are simultaneously in contact and stimulated by several cues. Therefore, this review explores the synergistic effect of biochemical/physical cues in regulating cellular events, namely cell adhesion, proliferation, osteogenic differentiation, and mineralization, highlighting the importance of the combined modifications for the development of innovative bone regenerative therapies.

To analyze the biocompatibility of the scaffold produced from a natural polymer derived from castor oil through hemolytic activity and antimicrobial activity, to enable the clinical application. Three in vitro tests were performed: Hemolytic activity test - Polymer partially dissolved in contact with blood agar; Hemolytic activity test in sheep's blood - Polymer extract with red blood cells solution; Antimicrobial activity test - Solid polymer in direct contact with E. Coli and S. Aureus. For hemolytic tests, none of the samples showed hemolysis. Negative hemolytic activity is a good indicator, as the maintenance of the blood clot in the area of the lesion is essential for the formation of new tissue. For the antimicrobial activity test, no significant activity was observed against the bacteria used. The polymer is not toxic to red blood cells, being viable for clinical application as a matrix for tissue regeneration.

Use biological or synthetic scaffolds to conduct cellular events of the regenerative process constitute one of the major strategies in regenerative medicine area. Customized scaffolds built by additive manufacturing prove to be a great solution to this problem. Two desired features that aid in scaffold’s biocompatibility are the surface roughness and the geometric characteristic of the topography, usually achieved by a chemical procedure performed after printing. This research presented a modification on a 3D printer nozzle for directly generating an external topography in the extruded filaments, eliminating the need for an additional post-processing step. Cell morphology and viability on supports printed by the proposed and conventional method were evaluated in in vitro experiments and the new nozzle proved to be efficient in generating printed filaments with a degree of cytocompatibility superior to those obtained by conventional filaments.

Because bone-associated diseases are increasing, a variety of tissue engineering approaches with bone regeneration purposes have been proposed over the last years. Bone tissue provides a number of important physiological and structural functions in the human body, being essential for hematopoietic maintenance and for providing support and protection of vital organs. Therefore, efforts to develop the ideal scaffold which is able to guide the bone regeneration processes is a relevant target for tissue engineering researchers. Several techniques have been used for scaffolding approaches, such as diverse types of biomaterials. On the other hand, metallic biomaterials are widely used as support devices in dentistry and orthopedics, constituting an important complement for the scaffolds. Hence, the aim of this review is to provide an overview of the degradable biomaterials and metal biomaterials proposed for bone regeneration in the orthopedic and dentistry fields in the last years.

Background: This study aims to investigate the effects of the local application of doxycycline in the form of natrosolbased gel on bone regeneration by examining critical defects in rat calvaria. Methods: Twenty-four rats were randomly divided into three groups with eight animals each, according to the treatment received: BC (untreated, filled with blood clot), NAT (natrosol gel alone), and DOX (10% doxycycline gel). Four animals from each group were euthanized at 4 and 8 weeks postoperatively. In tomographic analysis, mean density in the region of the defect was calculated as a percentage relative to the native bone density. In histomorphometric analysis, the newly formed bone area was calculated as a percentage of the total area. The values obtained underwent analysis of variance and Tukey testing (P <0.05). Results: The mean percentage of tomographic density in the region of the defect at the end of 8 weeks was higher for DOX (44.37%), and statistical differences in this period were observed between DOX and NAT (33.10%) and DOX and BC (32.43%). Regarding new bone formation, at the end of 8 weeks, DOX (61.11%) also had the highest mean bone formation, and statistical differences were observed between DOX and NAT (34.61%) and DOX and BC (23.11%). Conclusion: It was observed that 10% doxycycline gel had a good effect on bone regeneration regarding the filling of critical defects in rat calvaria.

INTRODUÇÃO: O reparo tissular é o objetivo final da cirurgia. A cultura celular requer arcabouço mecânico que dê suporte ao crescimento celular e difusão dos nutrientes. O uso do plasma rico em plaquetas (PRP) como um arcabouço 3D possui diversas vantagens: é material biológico, de fácil absorção pós-transplante, rico em fatores de crescimento, em especial PDGF- ββ e TGF-β que estimula síntese de matriz extracelular na cartilagem. OBJETIVO: Desenvolver arcabouço 3D à base de PRP. MATERIAIS E MÉTODOS: Duas formas foram idealizadas: Sphere e Carpet. Condições estéreis foram utilizadas. O gel de plaquetas permaneceu em cultura celular, observado diariamente em microscópio invertido. RESULTADOS: Ambos arcabouços obtiveram sucesso, com aspectos positivos e negativos. DISCUSSÃO: A forma Sphere não aderiu ao plástico. Observou-se retração do gel e investigação ao microscópio dificultada devido às áreas opacas no campo visual. A forma Carpet não aderiu ao plástico e apresentou-se translúcida. O tempo de estudo foi de 20 dias. CONCLUSÕES: A produção de um arcabouço 3D PRP foi um sucesso, e trata-se de uma alternativa que necessita ser mais utilizado e investigado para que se consolide em uma rota eficiente e confiável na tecnologia de engenharia tissular, particularmente em cultura de tecido cartilaginoso.

Bacterial cellulose (BC) produced by some bacteria, among them Gluconacetobacter xylinum, which secrets an abundant 3D networks fibrils, represents an interesting emerging biocompatible nanomaterial. Since its discovery BC has shown tremendous potential in a wide range of biomedical applications, such as artificial skin, artificial blood vessels and microvessels, wound dressing, among others. BC can be easily manipulated to improve its properties and/or functionalities resulting in several BC based nanocomposites. As example BC/collagen, BC/gelatin, BC/Fibroin, BC/Chitosan, etc. Thus, the aim of this review is to discuss about the applicability in biomedicine by demonstrating a variety of forms of this biopolymer highlighting in detail some qualities of bacterial cellulose. Therefore, various biomedical applications ranging from implants and scaffolds, carriers for drug delivery, wound-dressing materials, etc. that were reported until date will be presented.

Avanços na engenharia tecidual trazem possibilidades terapêuticas inovadoras na odontologia, aliados a reabilitação oral do paciente. Dentro da endodontia, este campo é bastante novo e promissor, uma vez que pode revolucionar os tratamentos atuais utilizados para as doenças de polpa dentária e fornecer uma possibilidade de regeneração pulpar.Os scaffolds são estruturas tridimensionais semelhantes ao tecido original, em textura macro e micro-geometria favorecendo a adesão celular e sua consequente expressão. O melhor scaffold para a engenharia de tecidos seria a matriz extra-celular descelularizada do tecido alvo, uma vez que, a descelularização permite que os pesquisadores obtenham matrizes naturais, livres de células, caracterizadas por organização 3D adequada e composição molecular adequada. Este estudo se propôs a uma revisão sistemática sobre os melhores métodos para descelularização e recelularização da polpa dentária para a confecção de scaffolds naturais para utilização em revitalização pulpar. Um total de 300 referências foi recuperado nas bases de dados eletrônicas pesquisadas até maio de 2020, com primeira pesquisa realizada em julho de 2019. Após a remoção das duplicatas 174 títulos / resumos foram avaliados por dois revisores independentes, calibrados de acordo com os critérios de elegibilidade propostos. O resultado do processo de calibração demonstrou um nível de concordância substancial entre os revisores (κ =0.75) e um total de 6 artigos foram incluídos na sintese qualitativa de resultados. Estudos in vitro e in vivo dos estudos recuperados demonstraram algum nível de resultados positivos em relação aos testes biológicos, mesmo à luz dos diferentes níveis de complexidade dos testes realizados entre os diferentes estudos. Resultados promissores foram observados no desenvolvimento de scaffolds biológicos decelularizados derivado da polpa dentária com a perseveração de componentes estruturais extracelulares necessários para regeneração tecidual. No entanto, os dados atuais são heterogêneos demais para comparar e identificar as vantagens de qualquer método específico utilizado nos estudos recuperados.