In order to face this situation, biomaterials have been used for the production of three-dimensional (3D) structures, denominated scaffolds, which provide more advantages than powder, granulated materials or even some of the before mentioned transplants. These scaffolds have the potential to induce bone regeneration and are able to degrade after a certain period after implantation [2][3][4]. The achievement of stable direct contact between bone and the scaffold surface is a critical requirement for the development of optimal scaffolds and such surface contact must be structural, mechanical and functional. In addition, non-toxicity, biocompatibility and an adequate mechanical strength are necessary to obtain suitable scaffolds for implantation.The scaffold's microstructure could range from membranes to porous structures. Also for their fabrication, several biodegradable materials (synthetic polymers as polycaprolactone, polylactic-co-glycolic acid, polyethylene Fabrication of chitosan/bioactive glass composite scaffolds for medical applicationsABSTRACT: In the current study, a bioactive glass (BG) powder was prepared by sol-gel technique in the system SiO 2 -CaO-P2O5, and both, bioactive glass precursors (BGi) and the powder of bioactive glass (BGp) were used to produce crosslinked chitosan composite scaffolds (CH/BGi and CH/BGp), which were produced by lyophilization. The bioactive glass was analyzed to know its composition, crystallinity and morphology through Raman Spectroscopy (RS), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. In addition, compression strength tests were carried out on the resulting composite scaffolds. Experimental results show that the fabricated CH/BG scaffolds might be a promising composite biomaterial for bone tissue engineering, due to the XRD results, showing a pollutant-free biomaterial, and, SEM shows bioactive glass particles homogenously distributed within the chitosan matrix which suggested that the developed composite scaffolds possess the prerequisites for tissue engineering and these can be used for tissue engineering applications. RESUMEN:En el presente estudio, un polvo de vidrio bioactivo (VB) fue preparado por la técnica sol-gel en el sistema SiO2-CaO-P2O5, y ambos, precursores de vidrio bioactivo (VBi) y polvo de vidrio bioactivo (VBp) se utilizaron para producir andamios compuestos por quitosano y vidrio bioactivo (Qno/VBi y Qno/VBp), los cuales fueron producidos por liofilización. El vidrio bioactivo fue analizado para conocer su composición, cristalinidad y morfología a través de Espectroscopía Raman (RS), Difracción de Rayos X (DRX) y Microscopía Electrónica de Barrido (MEB), respectivamente. Además, pruebas de resistencia a la compresión se llevaron a cabo sobre los andamios compuestos resultantes. Los resultados experimentales muestran que los andamios de Qno/VB podrían ser un biomaterial compuesto muy prometedor para ingeniería de tejido óseo, debido a los resultados de DRX, que muestra un biomaterial libre de contaminantes, además e...

The regeneration of bone is one of the main challenges of modern medicine because many diseases, including trauma and tumor, can cause bone defects. Tissue engineering (TE) is a promising approach to cure these bone diseases because it allows the reconstruction of tissue by colonization and proliferation of healthy cells in an artificial extracellular matrix (scaffolds). The aim of this project was to prepare chitosan/hydroxyapatite CH/HA scaffolds, using various ratios and two different methods: powder hydroxyapatite (commercial) and in situ hydroxyapatite, and then compare their properties. The morphology, chemical composition and mechanical properties were evaluated by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and compression tests. The scaffolds obtained showed an interconnected porous structure. The scaffolds with chitosan and hydroxyapatite manufacturing by in situ protocol, have better applications in tissue engineering, because they have a better morphology and allow the cell growth. These scaffolds are suitable for tissue engineering.----------Keywords: bone, chitosan, hydroxyapatite in situ, hydroxyapatite in powder, scaffolds chitosan/ hydroxyapatite, tissue engineering

The skeletal system is vulnerable to injuries and bone loss over the years, making the use of autologous or allogeneic implants necessary. However, these implants have complications, such as the limited amount of bone to be extracted and the cell death at the extraction site; hence, biomaterials have been developed as platforms for cell growth (scaffolds). Biomaterials and bones have similar properties that facilitate the integration between the material and the bone tissue, helping the tissue to regenerate. Traditional ceramic implants are hydroxyapatite, but given their low mechanical properties, they have been replaced with better inert ceramics. Therefore, this study aims at manufacturing titanium dioxide scaffolds through various techniques, using collagen, polyvinyl alcohol (PVA), sodium chloride, and corn flour as binders to influence pore size. Scaffolds were characterized by a Scanning Electron Microscope (SEM) and evaluated by compression and degradability tests in a Simulated Body Fluid (SBF). The prepared scaffolds had mechanical behaviors with ranges within the bone parameters; among them, the scaffold obtained by infiltration with 10% PVA presented values of compression strength (6.75 MPa), elastic modulus (0.23 GPa), and porosities (54-67%) closer to the values of the trabecular bone.

Chitosan has gained agro-industrial interest due to its potential applications in food preservation. In this work, chitosan applications for exotic fruit coating, using feijoa as a case of study, were evaluated. For this, we synthetized and characterized chitosan from shrimp shells and tested its performance. Chemical formulations for coating preparation using chitosan were proposed and tested. Mechanical properties, porosity, permeability, and fungal and bactericidal characteristics were used to verify the potential application of the film in the protection of fruits. The results indicated that synthetized chitosan has comparable properties to commercial chitosan (deacetylation degree > 82%), and, for the case of feijoa, the chitosan coating achieved significant reduction of microorganisms and fungal growth (0 UFC/mL for sample 3). Further, membrane permeability allowed oxygen exchange suitable for fruit freshness and natural physiological weight loss, thus delaying oxidative degradation and prolonging shelf-life. Chitosan’s characteristic of a permeable film proved to be a promising alternative for the protection and extension of the freshness of post-harvest exotic fruits.

En el presente trabajo se realizó un estudio estadístico para optimizar el rendimiento del proceso de extracción de fibroína del capullo del gusano de seda Bombyx Mori, también conocido como desgomado, en el cual la fibroína y la sericina, componentes que conforman la estructura del capullo, son separadas utilizando soluciones acuosas de carbonato de sodio (Na2CO3); el estudio en cuestión se hizo mediante un diseño experimental 23 con dos puntos centrales, para ello, los factores seleccionados fueron la temperatura, la relación Na2CO3/Capullos y el tiempo de extracción. La significativa estadística de estos factores fue estudiada mediante análisis de varianza (ANOVA). De acuerdo con los resultados, el proceso de extracción depende principalmente del tiempo de extracción (p = 0,009) y la temperatura de trabajo (p = 0,0112), obteniéndose bajo las condiciones óptimas de extracción un promedio de 74,76% de fibroína del capullo. Finalmente, la muestra obtenida bajo las mejores condiciones se caracterizó por medio de análisis Infrarrojo por Transformada de Fourier (FTIR) y por análisis termogravimétrico (TGA) con el fin de tener la base del material obtenido para posibles aplicaciones biomédicas.