Polímeros biorreabsorvíveis como substrato para cultura de células e engenharia tecidual

Cashew gum as future multipurpose biomacromolecules

The review highlights significant advances in delivery systems, with an emphasis on the use of cashew gum (CG), a natural polysaccharide extracted from Anacardium occidentale L., recognized for its remarkable biodegradability and versatility. CG has a wide range of applications spanning sectors such as food, pharmaceuticals, agriculture, and biotechnology. This study examines research focused on the extraction, purification, and chemical modifications of CG, as well as its combination with other biopolymers to enhance physicochemical and mechanical properties. These strategies aim to optimize the gum's characteristics, allowing for the creation of innovative materials with improved performance, expanding its potential applications. This review aims to provide a comprehensive overview of recent research trends, focusing on the utilization of CG as a polymeric component in the development of biomaterials with diverse applications.

Biological performance of a bioabsorbable Poly (L-Lactic Acid) produced in polymerization unit: in vivo studies

Background: The biomaterials engineering goal is to manufacture a biocompatible scaffold that adequately supports or improves tissue regeneration after implantation of the biomaterial in the injured area. Many requirements are demanded for a biomaterial, such as biocompatibility, elasticity, degradation time, and a very important factor is its cost of importation or synthesis, making its application inaccessible to some countries. Studies about biomaterials market show that Polylactic acid (PLLA) is one of the most used polymers, but expensive to produce. It becomes important to prove the biocompatibility of the new PLLA and to find strategies to produce biocompatible biopolymers at an acceptable production cost. Methods: In this work, the polylactic acid biomaterial was synthesized by ring-opening polymerization. The polymer was submitted to initial in vivo biocompatibility studies in 12 New Zealand female rabbits, assigned to two groups: (1) Lesion and PLLA group (n = 6), (2) Lesion No PLLA group (n = 6). Each group was divided into two subgroups at six and nine months post-surgical time. Before euthanasia clinical and biochemical studies were performed and after that tomographic (CT), histological (Hematoxylin and Eosin and Masson's trichrome) and histomorphometric analyses were performed to evaluate the injury site and prove biocompatibility. The final cost of this polymer was analyzed. Results: The statistical studies of hemogram and hepatocyte enzymes, showed that there were no significant differences between the groups for any of the times studied, in any of the variables considered and the results of CT and histology showed that there was an important process of neoregeneration. The cost analysis showed the biopolymer synthesis is between R$3,06 - R$5,49 cheaper than the import cost. Conclusions: It was possible to synthesize the PLLA biopolymer by cyclic ring opening, which proved to be biocompatible, potential osteoregenerative and cheaper than other imported biopolymers.

Electrospun natural rubber latex biocomposite for scaffolds in tissue engineering

Fibrous scaffold along with seed cells are essential players for engineered tissue regeneration. Recently, PLGA/epoxidized poly(isoprene) dense membranes have been evaluated for cell growth and have shown satisfactory results. However, porous and fibrous structures suitable for obtaining 3D supports have not yet been evaluated for the PLGA/epoxidized poly(isoprene). The present work aimed to establish the electrospinning conditions for obtaining electrospun membranes with a smaller diameter of fibers and adequate morphology, which were characterized in vitro by their physical, chemical and biological properties. The best electrospun fibers were obtained from the following conditions: an applied voltage of 15 kV, a needle-collector distance of 20 cm and, a flow rate of 5 mL/h. The functional groups of the polymers involved in the blend did not show any changes. The mechanical properties of the electrospun membranes are within the lower limits known to human skin and some soft tissues. The in vitro degradation test showed a loss of mass of approximately 20% in 28 days. Significant adhesion and proliferation of human adipose–derived mesenchymal stem cells were demonstrated, indicating that there was cellular penetration into the scaffold and proliferation. Therefore, the preliminary results suggest that the electrospun PLGA/epoxidized poly(isoprene) membranes have high potential for application as a 3D tissue engineering scaffold.

Hidrogéis a base de ácido hialurônico e quitosana para engenharia de tecido cartilaginoso

Resumo A Engenharia de Tecidos envolve o desenvolvimento de novos materiais ou dispositivos capazes de interações específicas com os tecidos biológicos, buscando a utilização de materiais biocompatíveis que devem servir como arcabouço para o crescimento de células in vitro, organizando e desenvolvendo o tecido que posteriormente será implantado no paciente. Uma variedade de arcabouços como hidrogéis poliméricos, sintéticos e naturais, têm sido investigados para a expansão de condrócitos in vitro, visando o reparo da cartilagem lesionada. Um hidrogel de interesse particular na regeneração de cartilagem é o ácido hialurónico (AH). Trata-se de um biopolímero atraente para a fabricação de arcabouços artificiais para Engenharia de Tecidos por ser biocompatível e biodegradável. A biocompatibilidade do AH deve-se ao fato de estar presente na matriz extracelular nativa, deste modo, cria-se um ambiente propício que facilita a adesão, proliferação e diferenciação celular, além da existência de sinalização celular específica, o que contribui para a regeneração do tecido. O uso de hidrogel composto de ácido hialurónico e quitosana (QUI) também tem sido investigado em aplicações de Engenharia de Tecidos de cartilagem, com resultados promissores. Baseando-se nestas informações, o objetivo este trabalho foi investigar as alternativas disponíveis para regeneração tecidual da cartilagem e conhecer mais detalhadamente as relações entre células e biomateriais.

Cellular and morphological aspects of fibrodysplasia ossificans progressiva. Lessons of formation, repair, and bone bioengineering

Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disease that causes bone formation within the muscles, tendons, ligaments and connective tissues. There is no cure for this disorder and only treatment of the symptoms is available. The purpose of this study was to review the literature and describe the clinical, cellular and molecular aspects of FOP. The material used for the study was obtained by reviewing scientific articles published in various literature-indexed databases. In view of its rarity and of the lack of insightful information and the unpredictability of its course, FOP is a challenging disorder for professionals who are confronted by it. However, this rare disease raises a great deal of interest because understanding the mechanism of mature bone formation can encourage research lines related to bone regeneration and the prevention of heterotopic ossification.

Citocompatibilidade de blendas de poli(p-dioxanona)/ poli(hidroxi butirato) (PPD/PHB) para aplicações em engenharia de tecido cartilaginoso

Buscando estratégias que repercutam na melhoria da interação entre materiais poliméricos biorreabsorvíveis e o crescimento celular, o presente estudo in vitro teve como objetivo estudar a influência de blendas de PPD/PHB na adesão celular e crescimento de fibrocondrócitos obtidos a partir de cultura primária. As blendas de PPD/PHB foram preparadas pelo método de evaporação de solvente nas composições 100/0, 60/40 e 50/50 e caracterizadas por microscopia eletrônica de varredura (MEV). Observações ultra-estruturais mostraram alterações na morfologia celular, sugerindo que os fibrocondrócitos podem responder a alterações no substrato alterando seu perfil fenotípico. As análises com MTT demonstraram que as blendas não apresentaram citotoxicidade e permitiram a adesão e proliferação dos fibrocondrócitos sobre os substratos em todas as suas composições. O ensaio colorimétrico com Sirius Red evidenciou a capacidade de manutenção da síntese de matriz extracelular colágena sobre as amostras, concluindo-se que as blendas de PPD/PHB podem ser indicadas para o cultivo celular.