Scaffolds are devices with interconnected pores that favor cell interaction and proliferation. They play a significant role in tissue engineering, as they mimic the conditions of tissue production in vivo. The aim of this study was to synthesize scaffolds of chitosan, collagen, and Jatropha mollissima by lyophilization and characterize their chemical/biodegradability and morphological properties. For that, techniques of optical microscopy, infrared spectrometry, biodegradation test, and degree of swelling were performed. A 2% (m/v) chitosan/collagen (1:9) in lactic acid solution was produced. Then, Jatropha mollissima crude extract was added to this solution in different proportions of mass (5, 10, and 15%). Optical microscope images indicated the three-dimensional network formation with interconnected pores and predominantly lamellar shape. Through infrared spectrometry, characteristic bands indicated a physical mixture. Also, the swelling degree of all samples was proportional to the amount of Jatropha mollissima extract with the highest percentage of 1852%. Biodegradation test also revealed a proportional ratio between the amount of sap used and the degraded percentage with the lowest value of around 35% in 28 days. In conclusion, it can be inferred that the scaffolds produced show potential to be used in tissue engineering as dressings. proliferation vivo chitosan collagen chemicalbiodegradability chemical biodegradability properties microscopy spectrometry performed 2 m/v mv m v (m/v chitosancollagen 19 1 9 (1:9 Then 5, 5 (5 10 15%. 15 15% . 15%) threedimensional three dimensional shape mixture Also 1852 1852% 35 days conclusion dressings (1: ( 185 3 (1 18

This study aimed to develop and evaluate chitosan (CS) and chitosan with N-Acetyl-D-glucosamine (CS/GlcNAc) sutures, comparing them to commercial Catgut sutures. Medium molecular weight chitosan was processed into sutures using the wet-spinning method, both with and without the addition of GlcNAc. The mechanical properties, surface morphology, biocompatibility, biodegradability and in vivo response of the sutures were evaluated. Scanning electron microscopy (SEM) and enzymatic degradation tests in phosphate-buffered saline (PBS) with lysozyme were conducted. Cytotoxicity was assessed using an agar diffusion assay on L929 cells. In vivo studies involved suturing rat skin, with monitoring at 5, 15 and 25 days post-surgery. Both macroscopic and microscopic analyses were performed to evaluate wound healing, tissue response, and complications. The chitosan-based sutures exhibited tensile strength within the standards for surgical sutures under dry and hydrated conditions. Particularly, the CS/GlcNAc sutures exhibited superior biodegradability, and biocompatibility compared to Catgut sutures. These sutures promoted tissue healing, reduced adverse tissue reactions and infections, and displayed non-toxic to L929 cells and favorable microbiological characteristics. Thus, CS and CS/GlcNAc sutures present promising alternatives to traditional Catgut sutures, contributing valuable advancements to the field of biodegradable surgical materials. (CS NAcetylDglucosamine N Acetyl D glucosamine CSGlcNAc GlcNAc (CS/GlcNAc wetspinning wet spinning method properties morphology evaluated SEM (SEM phosphatebuffered phosphate buffered PBS (PBS conducted L L92 skin 5 1 2 postsurgery. postsurgery post surgery. surgery post-surgery healing complications chitosanbased based conditions Particularly infections nontoxic non toxic characteristics Thus materials L9

ABSTRACT The urine bag is a thermo-labile medical-hospital device used in clinical/surgical procedures in urine drainage and collection. As it is a thermolabile material, it is commonly sterilized by ethylene oxide, a highly toxic, mutagenic and carcinogenic cyclic ether gas. Currently, several countries require, through documents and standards, the quantification of ethylene oxide in medical and hospital devices. Thus, this work describes the development and validation of a method employed for the quantification of ethylene oxide (ETO) in urine bags. The method was developed based on the guidelines of ISO 10993-7, ANVISA and INMETRO. The work range, linearity, limits of detection and quantification, repeatability, intermediate precision and selectivity were evaluated. Statistical tools such as Levene's test, Grubbs, residual analysis, F-test of two variances, paired sample T test and ANOVA table, were also applied to evaluate the method. The linearity of the work range (10 – 400 mg.L-1) showed an adequate correlation coefficient (r > 0.9993), with a homoscedastic profile with absence of outliers while the limit of detection and quantification were 1,95 and 6,5 mg.L-1 respectively. After validation, 45 samples of urine bags of different batches were evaluated, which demonstrated levels of ETO below the limit of detection (1,95 mg.L-1). The results highlight a simple method that meets several regulations with a wide working range, high sensitivity and capability to quantify ETO not only in urine bags but also in other medical devices. thermo labile medicalhospital clinicalsurgical clinical surgical collection material toxic gas Currently require standards devices Thus (ETO 109937, 109937 10993 7, 7 10993-7 INMETRO repeatability evaluated Levenes Levene s Grubbs analysis Ftest F variances table 10 (1 40 mg.L1 mgL1 mgL mg.L 1 mg L r 0.9993, 09993 0.9993 , 0 9993 0.9993) 195 95 1,9 65 6 5 6, mg.L- respectively 4 (1,9 mg.L1. . 1099 10993- ( L1 0999 0.999 999 19 9 1, (1, 109 099 0.99 99 09 0.9 0.

RESUMO A investigação de novas formas farmacêuticas para o tratamento de queimaduras, representa um importante avanço tecnológico na área de engenharia de tecidos. Nesse contexto, os hidrogéis à base de poli(álcool vinílico)(PVA) e quitosana(CS) funcionalizados com o óleo essencial de melaleuca surgem como excipientes promissores para uso como curativos, buscando através de um efeito sinérgico obter biomateriais com amplos espectros de ação biológica possível de acelerar e ser eficiente no reparo e cicatrização de tecidos lesionados como queimaduras. Para tanto, a presente pesquisa teve como objetivo a produção e caracterização de hidrogéis PVA/CS nas proporções 1:1 e 1:2 (m/v), respectivamente, funcionalizadas com 3% (v/v) do óleo de melaleuca (OM) pelo método casting, visando a aplicação como curativos. Os hidrogéis funcionalizados foram analisados qualitativamente por inspeção visual e analisados por ensaios de intumescimento e molhabilidade por ângulo de contato assim como caracterizados por microscopia eletrônica de varredura (MEV) e difratometria de raios X (DRX). Mediante a inspeção visual, a maioria dos hidrogéis apresentaram-se translúcidos, exceto o hidrogel PVA+3%OM que teve excelente transparência ótica. No geral, os hidrogéis apresentaram caráter superhidrofílico e bom grau de intumescimento na presença dos fluidos, água destilada e PBS, indicando que esses hidrogéis funcionalizados com óleo de melaleuca mostram-se promissores para aplicação como curativos na regeneração de tecidos lesionados.

ABSTRACT The investigation of new pharmaceutical forms for the treatment of burns represents an important technological advance in the area of tissue engineering. In this context, poli(vinyl alcohol)(PVA) and chitosan(CS) hydrogels functionalized with tea tree essential oil appear as promising excipients for use as dressings, seeking through a synergistic effect to obtain biomaterials with broad spectrum of biological action possible to accelerate and be efficient in the repair and healing of injured tissues such as burns. For this purpose, the present research aimed at the production and characterization of PVA/CS hydrogels in the proportions 1:1 and 1:2 (w/v), respectively, functionalized with 3% (v /v) of tea tree oil (OM) by the casting method, aiming at the application as dressings. The functionalized hydrogels were analyzed qualitatively by visual inspection and analyzed by swelling and wettability tests as well as characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Upon visual inspection, most hydrogels were translucent, except for the PVA+3% OM hydrogel, which had excellent optical transparency. In general, the hydrogels had a superhydrophilic character and a good degree of swelling in the presence of fluids, distilled water and PBS, indicating that these hydrogels functionalized with tea tree oil are promising for application as dressings in the regeneration of injured tissues.

Abstract Crosslinking of chitosan (CS) woven meshes is reported in this study. CS filaments were obtained by wet spinning and hand-waved. The weft was coated with CS solutions (3 and 4% w/v) and crosslinked with sodium tripolyphosphate or genipin. CS filaments were free from superficial pores, and their mechanical properties were suitable for the weaving process. CS concentration in the coating, type, and the crosslinking time affected the mesh morphology obtained. Crosslinking by both agents was confirmed by spectroscopy, corroborating the reduction of the hydrophilicity of the crosslinked samples in the swelling and contact angle tests. Crosslinking conditions were effective in reducing the mechanical properties variation in the wet state, as well as regulating the degradation rate of the samples. Furthermore, it was observed that crosslinking did not significantly affect the cell viability of CS woven meshes, making them promising materials for application as stress material in a physiological environment.

RESUMO A membrana de látex tem ganhado destaque em uma gama de aplicações, entretanto, a baixa uniformidade em sua espessura provoca discrepância nas propriedades se configurando como problema para a produção em larga escala, principalmente quando se trata de um produto para área biomédica. Portanto, este artigo pretende determinar a influência da espessura sobre as propriedades de membranas derivadas de látex natural. Para tanto, foram produzidas amostras com espessuras de 0,35 mm, 0,40 mm, 0,50 mm, 0,60 mm e 0,65 mm e foram submetidas aos ensaios de dureza, absorção e perda em água, molhabilidade por ângulo de contato e resistência mecânica à tração. Os resultados mostraram que quanto maior a espessura, menor foi a dureza, a absorção de água, o módulo de Young, a deformação e a molhabilidade, porém, maior foi a resistência à tração e a perda de massa em água. O desvio padrão das propriedades das amostras com espessura entre 0,40 mm e 0,60 mm foi até 550% inferior aos desvios encontrados para 0,35 mm e 0,50 mm, até 930% menor para 0,50 mm e 0,65 mm e para as faixas de espessuras entre 0,35 mm e 0,65 mm a diminuição foi de até 800%. Dessa forma, se conclui que para padronizar a produção de membranas de látex, garantindo boa uniformidade nas suas propriedades, as espessuras devem ser de 0,50 mm com desvio de 0,1 mm.

ABSTRACT The latex membrane has been gained prominence in several applications; however, the low uniformity in its thickness causes a discrepancy in properties, becoming a problem for large-scale production, especially when it comes to a product for the biomedical area. Therefore, this article aims to determine the influence of thickness on the properties of membranes derived from natural latex. For this, samples were produced with thicknesses of 0.35 mm, 0.40 mm, 0.50 mm, 0.60 mm, and 0.65 mm and subjected to hardness tests, water absorption and loss, wettability by the contact angle, and mechanical resistance. The results showed that the greater the thickness, the lower the hardness, the water absorption, Young's modulus, tensile deformation, and the wettability, but, greater was the tensile strength and the mass loss in water. The standard deviation of the properties of samples with a thickness between 0.40 mm and 0.60 mm was up to 550% less than the deviations found for 0.35 mm and 0.50 mm, up to 930% below for 0.50 mm and 0, 65 mm and up to 800% smaller for thickness ranges between 0.35 mm and 0.65 mm. Thus, to standardize the production of latex membranes, ensuring good uniformity in their properties, thicknesses must be 0.50 mm with 0.1 mm deviation.

RESUMO O objetivo do presente trabalho foi produzir e caracterizar um biomaterial na forma de esferas de quitosana/ Dysphania ambrosioides (L.) Mosyakin & Clemants (mastruz) a fim de associar características positivas de ambos materiais, a quitosana com potencial osteoindutor e o mastruz capacidade de regeneração óssea, formando biomaterial a ser utilizado na formação e regeneração óssea. A planta foi coletada, identificada botanicamente e obtido extrato alcoólico bruto de Dysphania ambrosioides (L.) Mosyakin & Clemants (EAB). Para produção das esferas de quitosana e quitosana com EAB utilizou-se a técnica de Gelificação Ionotrópica. As esferas foram divididas em três grupos: um grupo de quitosana pura, outro com concentração menor de EAB e o terceiro com a maior concentração de EAB. Estas foram caracterizadas por Microscopia Óptica (MO), Microscopia Eletrônica de Varredura (MEV) e análise do Grau de Intumescimento (GI). A MO evidenciou nas superfícies externa e interna, esferas com limites definidos e com mudança de cor à medida que o percentual do EAB foi aumentado, tornando-se mais escuras. A MEV revelou, em esferas de maior concentração, quando comparado as de menor concentração: uma diminuição no tamanho e aumento da quantidade e da intercomunicação dos poros, além da alteração do formato geométrico tanto das esferas quanto dos seus poros. Na análise do Grau de intumescimento não houve diferenças significativas entre os grupos. Conclui-se que foi possível a produção de esferas de quitosana e quitosana/ Dysphania ambrosioides (L.) Mosyakin & Clemants (mastruz), que no grupo com maior percentual de EAB as amostras apresentaram-se mais escuras e com maior quantidade e intercomunicação dos poros e que embora tenha havido o intumescimento, não foi observada diferença significativa entre os grupos.

ABSTRACT The objective was to produce and characterize a biomaterial in the form of chitosan spheres/ Dysphania ambrosioides (L.) Mosyakin & Clemants (mastruz) in order to associate positive characteristics of both materials, chitosan with osteoinductive potential and the bone regeneration ability of mastruz, producing a biomaterial to use as bone former and regenarator. Plant specimens were collected, identified botanically and crude alcohol extract (CAE) were obtained. For the production of the chitosan and chitosan spheres with CAE, the Ionotrope Gellification technique was used. The spheres were divided into three groups: one example group of pure chitosan; a second example group with low CAE concentration and a third example group with a higher CAE concentration; and them characterized by Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and swelling degree (SD). OM showed on the external and internal surfaces, spheres with defined limits and with color changed as the percentage of CAE was increased, becoming darker. The SEM showed, in spheres with higher CAE concentration, in comparison with the ones with low CAE concentration: A decrease in size, increase in the quantity and intercommunication of the pores, and the alteration of the geometric shape of both the spheres and their pores. In the analysis of the swelling degree, there were no significant differences between the groups. It is possible to produce chitosan spheres / Dysphania ambrosioides (L.) Mosyakin & Clemants (mastruz) which in the group with the highest percentage of CAE the samples were darker and with higher amounts and intercommunication pores and that although there was swelling, no significant difference was observed between the groups.

Polyetheretherketone (PEEK) has been prominent in orthopedic implants; however, it is inert, preventing interaction between the implant and adjacent bone tissues. One way to overcome this characteristic is physical modification its on surface by particle leaching promoting greater osseointegration. The objective of this research was to develop and characterize the PEEK using a surface modification technique via particle leaching. For of the samples, a layer deposition of NaCl was used on PEEK. This was subjected to the pressure of 850 kg/cm2 by 390ºC for 20 minutes. After cooling, were subjected to leaching process particles. The results indicated a porous surface exhibiting uniform and homogeneous morphology with defined pores interconected, to in the range of 140-373 µm, with an average diameter of 273 µm. These evidenced the considerable NaCl removal after the leaching process, with cavities from ideal sizes which promotes adequate cellular accommodation and distinct roughness, giving an overall possibility of being able to obtain a material more able to receive the cells while also possibly presenting cell viability. Although the compressive strength presented low values, it can still be suitable for applications in areas with a reduced modulus of elasticity.

Abstract The aim of this study was to evaluate the degree of conversion (DC) and the thermal stability of bulk-fill and conventional composite resins. Eleven composite resin samples were prepared to evaluate the DC, Vickers microhardness (VMH), mass and residue/particle loss, glass transition temperature (Tg), enthalpy, and linear coefficient of thermal expansion (CTE) using infrared spectroscopy (FTIR), microdurometer analyses, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dilatometry (DIL). The data were subjected to statistical analysis, with a significance level of 95%. DC and VMH were not influenced by the polymerized side of the sample, and statistical differences were recorded only among the materials. Decomposition temperature, melting, and mass and residue loss were dependent on the material and on the evaluation condition (polymerized and non-polymerized). Tg values were similar between the composites, without statistically significant difference, and CTE ranged from 10.5 to 37.1 (10-6/°C), with no statistical difference between the materials. There was a moderate negative correlation between CTE and the % of load particles, by weight. Most resins had a DC above that which is reported in the literature. TGA, Tg, and CTE analyses showed the thermal behavior of the evaluated composites, providing data for future research, assisting with the choice of material for direct or semidirect restorations, and helping choose the appropriate temperature for increasing the DC of such materials.

Abstract Poly(ether ether ketone) (PEEK) has excellent properties, such as high biocompatibility and an elastic modulus similar to bone, which makes it a suitable biomaterial. When modified with sulfuric acid (H2SO4) and hydroxyapatite (HA), its workability and bioactivity is enhanced, and this makes it of great importance in medicine. This study investigates a better combination of process parameters to manufacture sulfonated PEEK/HA (SPEEK/HA) membranes for biomaterials. Chemical, thermal, and biological analyses were carried out on all samples. The sulfonated structure was observed to enhance wettability, adhesion, and cell viability. Furthermore, an increase in the degree of sulfonation facilitated their workability as required for biomaterials; making them suitable for osseointegration. Besides, the SPEEK/HA membranes presented cell adhesion, confirming the viability to use as biomaterial. This study presents a cheap alternative method to easily process biomaterials of improved workability.

RESUMO Com o presente estudo, objetivou-se comparar a técnica padrão do CXL com o tratamento utilizando a genipina como reticulante, com e sem desepitelização da córnea. Comparou-se propriedades químicas, mecânicas e morfológicas de córneas de suínos submetidas aos tratamentos de crosslinking com riboflavina egenipina, bem como comparar a citotoxicidade das soluções reticulantes, para possível aplicação no ceratocone. Para isso, as córneas foram divididas em quatro grupos: riboflavina e UVA conforme tratamento padrão, genipina com e sem desepitelização e controle sem reticulante. As córneas foram submetidas àscaracterizações de MO, MEV, ensaio de tração, dilatometria e intumescimento. A citotoxicidade foi realizada comparando o padrão com a genipina. Os resultados demonstram maior resistência à tração e maior grau de intumescimento quando a genipina foi aplicada após desepitelização da córnea. As inclinações descendentesna curva de dilatometria mostram-se lineares no UV-CXL e controle, e com a genipina, a contração tende a ficar mais acentuada em temperaturas maiores. Pela MEV foi verificada uma linha de demarcação no estroma corneano tratado com UV-CXL ou genipina e a MO exibiu padrões diversos de luz transmitida nos diferentesgrupos, demonstrando maior opacidade no UV-CXL. O crosslinking do colágeno corneano induzido pela genipina 0,1% produz aumento na resistência da córnea sem provocar opacidade corneana considerável, podendo ser útil no tratamento do ceratocone. O potencial de citotoxicidade aos fibroblastos se mostrou semelhante entre os métodos de reticulação.

ABSTRACT With the present study, we aimed to compare the standard technique of CXL with the treatment using genipine as a crosslinker, with and without corneal de-epithelialization. The chemical, mechanical and morphological properties of pig corneas submitted to crosslinking treatments with riboflavin and genipine were compared, as well as to compare the cytotoxicity of the crosslinking solutions for possible application in keratoconus. The corneas were divided into four groups: riboflavin and UVA according to standard treatment,genipina with epithelium off, genipina with epithelium on and control without crosslinker. In this way, the corneas were submitted to the characterizations and analyzed by the following techniques: OM, SEM, traction test, dilatometry and swelling. The cytotoxicity analysis was performed comparing the standard treatment with genipine. The results demonstrate a greater tensile strength, as well as more swelling when genipine was applied to the epithelium off corneal surface. The downward slopes in the dilatometry curve are linear in the UV-CXL and control, and with genipine, the contraction tends to become more pronounced at higher temperatures. By MEV was able to demonstrate a dmarcation line in the corneal stroma treated with UV-CXL or genipine and OM exhibits different patterns of transmitted light in the different groups, demonstrating greater UV-CXL opacity. The corneal collagen crosslinking induced by 0.1% genipine produces an increase in corneal resistance without causing considerable corneal opacity and may be useful in the treatment of keratoconus. The potential for cytotoxicity to fibroblasts was similar between crosslinking methods.

RESUMO Nanomateriais vem atraindo bastante atenção nos últimos anos em virtude das suas propriedades que permitem aplicações em diversas áreas como: química, física, medicina, fármacos e engenharias. No universo dos nanomaterias, as nanopartículas de prata (AgNPs) tem despertado o interesse de vários pesquisadores devido ao seu potencial bactericida. Estudos recentes correlacionaram a eficácia da atividade antimicrobiana com a razão superfície-volume, morfologia, polidispersividade, tamanho de partícula e estabilidade das AgNPs. Este trabalho teve como objetivo compreender a influência do borohidreto de sódio (NaBH4) e do peróxido de hidrogênio (H2O2) nas propriedades das AgNPs. A síntese das AgNPs foi realizada através da redução química de íons de prata com NaBH4, na presença de H2O2 e Citrato de Sódio (SCT). Para determinar a influência causada pelo H2O2 e NaBH4, foram empregados diferentes variações de concentrações e volumes e ao resultado foi aplicado o Teste de Fisher para determinar a significância entre essas variáveis. As amostras foram caracterizadas por Espalhamento Dinâmico de Luz (DLS) e Potencial Zeta. Como resultado, o Teste de Fisher em conjunto com os valores obtidos de tamanho de partícula, estabilidade e polidispersividade determinaram variáveis estatisticamente iguais, ou seja, as variáveis que não influenciam estatisticamente na formação das partículas, bem como, a influência causada pela variação do H2O2 e do NaBH4 nas propriedades das AgNPs. Por fim, a variação da concentração de NaBH4 e volume de H2O2 causam efeitos sob o diâmetro, estabilidade e polidispersividade de AgNPs os quais foram estudados e aqui estão descritos.

ABSTRACT Nanomaterials has attracted a lot of attention in recent years due to its properties that allow applications in several areas such as chemistry, physics, medicine, pharmaceuticals, and engineering. In the nanomaterial universe, silver nanoparticles (AgNPs) have awakened the interest of several researchers because of their bactericidal potential. Recent studies have correlated the efficacy of antimicrobial activity with the surfacevolume ratio, morphology, polydispersity, particle size and AgNPs stability. This work aimed to understand the influence of sodium borohydride (NaBH4) and hydrogen peroxide (H2O2) on the AgNPs properties. The synthesis of AgNPs was performed by chemical reduction of silver ions with sodium borohydride in the presence of hydrogen peroxide and sodium citrate. To determine the influence caused by H2O2 and NaBH4, different concentrations and volume variations were used and a Fisher’s exact test was applied to determine the significance between variables. The samples were characterized by Dynamic Light Scattering (DLS) and Zeta Potential. Results determined that the Fisher’s exact test along with the obtained results of variables of particle size, stability and polydispersity are statistically the same, that is, the variables do not influence statistically the formation of the particles, as well as the influence caused by H2O2 and NaBH4 variation on the AgNPs properties. In summary, variation of NaBH4 concentration and H2O2 volume causes effects under the diameter, stability and polydispersity of AgNPs which have been studied and described herein.

RESUMO Os polímeros, devido às suas diversas aplicações e funcionalidades, estão entre os excipientes mais utilizados para a obtenção de formas farmacêuticas, ganhando destaque a quitosana. O objetivo deste trabalho foi desenvolver e avaliar comparativamente membranas de quitosana com diferentes concentrações da espécie vegetal Cissus verticillata (L.) Nicolson & C.E. Jarvis (insulina), para uso em sistema de liberação de fármaco. Foi realizada coleta, identificação botânica e obtenção do extrato alcoólico bruto (EAB) da planta. Para produção das membranas de quitosana e quitosana com EAB utilizou-se a técnica de evaporação do solvente. As membranas foram divididas nos grupos: MQ (Membrana de quitosana), MQ5 (Membrana de quitosana com 5% de EAB) e MQ20 (Membrana de quitosana com 20% de EAB), sendo as amostrascaracterizadas pelas técnicas de Microscopia Ótica (MO), Microscopia Eletrônica de Varredura (MEV), de Resistência à Tração e Citotoxicidade. Analisando macroscopicamente as membranas, evidenciou-se mudança de cor à medida que o percentual do EAB foi aumentado, tornando as amostras mais escuras. As análises de MO e MEV evidenciaram membranas com superfície lisa e regular. O ensaio mecânico de resistência à tração revelou diminuição na resistência à tensão quando acrescido 5% de EAB, e aumento desta com 20% de EAB. O teste de citotoxicidade mostrou que todas as amostras são viáveis para uso em sistemas biológicos. Logo, conclui-se que foi possível desenvolver membranas de quitosana com diferentes concentrações de EAB, e que o grupo MQ possui uma maior resistência à tensão em relação aos demais grupos.

ABSTRACT The polymers, due to their diverse applications and functionalities, are among the most used excipients to obtain pharmaceutical forms, with emphasis on chitosan. This study aimed to develop and evaluate comparatively membranes of chitosan to different concentrations of the plant species Cissus verticillata (L.) Nicolson & C.E. Jarvis (insulin), in order to use in a drug delivery system. It was realized data collection, botanical identification and the obtaining of the crude alcohol extract (CAE) of the plant. For the production of chitosan and crude alcohol extracted chitosan membrane, it is used the solvent evaporation technique. The membranes were divided into groups: CM (chitosan membrane), CM5 (5% of crude alcohol extracted chitosan membrane) e CM20 (20% of crude alcohol extracted chitosan membrane), being the samples characterized by the techniques of Optical Microscopy (OM), Scanning Electron Microscopy (SEM), of Tensile Strength and Cytotoxicity. Macroscopically analyzing the membranes revealed a change in color as the percentage of CAE increased, making the samples darker. The MO and SEM analyzes showed membranes with smooth and regular surface. The mechanical tensile strength test revealed a decrease in tensile strength when 5% of CAE was added and increased with 20% of CAE. The cytotoxicity test showed that all samples are viable for use in biological systems. Therefore, it was concluded that it was possible to develop chitosan membranes with different concentrations of CAE, and that the CM group has a higher resistance to tension in relation to the other groups.

RESUMO O elevado número de pacientes com problemas de saúde por doenças ósseas ou traumas tem promovido o desenvolvimento de pesquisas em biomateriais de modo a garantir uma melhor qualidade de vida. Dentre os diversos biomateriais, os cimentos ósseos poliméricos (PMMA) ou cerâmicos (fosfatos e silicatos de cálcio) destacam-se para aplicações em cirurgias ortopédicas e odontológicas, tais como: reconstrução óssea, artoplastia. Diante do exposto o objetivo da pesquisa foi avaliar a influência da incorporação de fosfatos de cálcio (β-TCP (amostra 1 -A1) e hidroxiapatita – HAp (amostra 2 – A2) na proporção de 2% (m/m) para a formação de cimento ósseo de silicato de cálcio (wollastonita/brushita) pelo método de dissolução/precipitação. A mistura do pó (wollastonita) foi homogeneizada, posteriormente uma solução de ácido fosfórico adicionada para formação do cimento ósseo, foram colocadas em um molde de teflon baseado com a norma ABNT NBR ISO 5833, e finalmente deixados a 25ºC por 24 horas obtendo os corpos de prova. A análise por DRX das amostras indicaram a presença das fases cristalinas do fosfato de cálcio (β-TCP e HAp) e silicato de cálcio (wollastonita e Brushita). As imagens das amostras por MEV apresentaram tamanho de partículas características da wollastonita/brushita/HAp/β-TCP. Foi realizado uma análise granulométrica a partir das micrografias, onde se observou que a incorporação dos fosfatos influencio na aglomeração dos tamanhos das partículas quando comparados ao cimento ósseo puro. O ensaio de compressão indica que a incorporação dos fosfatos melhora a propriedade mecânica, devido à redução das partículas o qual provoca uma maior compactação. Conclui-se que a A2 com a incorporação da HAp essa melhora da resistência mecânica foi mais intensa em relação a A1, no entanto, às duas amostras tiveram melhorias significativas em comparação ao cimento ósseo de silicato de cálcio.

ABSTRACT The high number of patients with health problems due to bone diseases or trauma has promoted the development of biomaterial research to ensure a better quality of life. Among the various biomaterials, polymeric (PMMA) or ceramic bone cements (phosphates and calcium silicates) stands out for such application. In view of the above, the objective of the research was to evaluate the incorporation of calcium phosphates (β-TCP (sample 1-A1) and hydroxyapatite-HAp (sample 2-A2) in the proportion of 2% (m/m) for the formation of calcium silicate bone cement (wollastonite / brushite) by the method of dissolution/precipitation. The powder mixture (wollastonite) was homogenized, subsequently a solution of phosphoric acid added to form the bone cement were placed in a teflon mold based on the ISO 5833 ABNT NBR standard, and finally left at 25ºC for 24 hours obtaining the specimens. XRD analysis of the samples indicated the presence of the crystalline phases of calcium phosphate (β-TCP and HAp) and calcium silicate (wollastonite and Brushite). The MEV images showed particle size wollastonite/brushite/HAp/β-TCP. A granulometric analysis was carried out from the micrographs, where it was observed that the incorporation of the phosphates influenced the agglomeration of the particle sizes when compared to the pure bone cement. The compression test indicates that the incorporation of the phosphates improves the compressive strength, due to the reduction of the particles which causes a greater compression. It is concluded that A2 with the incorporation of HAp this improvement of mechanical resistance was more intense in relation to A1, however the two samples had significant improvements in relation to calcium silicate bone cement.

ABSTRACT The chemical modification of chitosan (CH) from shrimp shells (Litopenaeus vannamei) was performed with amino acids: L-leucine (Leu) and L-tyrosine (Tyr), in order to change some of its physical and chemical properties, which allow the enhancement of the applications of chitosan in biomedical and pharmacological areas. The characterization of chitosan derivatives (CH-CH-Leu and Tyr) was performed by infrared spectroscopy studies (ATR-FTIR) to verify the new structure of the modified compounds. The thermal stability was analyzed by thermogravimetry (TGA). Solubility tests were carried out, where it was observed that the obtained derivatives are soluble in aqueous solutions at neutral and alkaline pH values, unlike the chitosan that is only soluble under acid pH conditions. The cytotoxicity of the derivatives was analyzed by hemocompatibility tests with human erythrocytes. Subsequently, membranes were obtain from the derivatives of CH-Leu and CH-Tyr, and contact angle was measured. The process of biodegradability in these membranes was studied through hydrolysis processes in H2O and phosphate buffered saline (PBS), pH 7.4 at 37ºC during time intervals of 24, 72 and 168 h. Scaffolds were prepared using the electrospinning technique to be able to prepare a mixture between poly (vinyl alcohol) (PVA) and CH derivatives (given their solubility in water) and the morphology was studied using scanning electron microscopy (SEM). In general, FTIR spectroscopy, TGA thermal analysis and SEM served as tools to verify the modification, and these derivatives allow to expand the physical and chemical properties of neat chitosan, mainly in terms of its solubility, allowing this novel biomaterial to be used in multiple applications, highlighting that they can be mixed with synthetic polymer phases which opens windows for the use of this interesting biopolymer.

RESUMEN Se realizó la modificación química de quitosano (CH) proveniente de conchas de camarón (Litopenaeus vannamei) con aminoácidos: L-leucina (Leu) y L-tirosina (Tyr), con el fin de variar algunas de sus propiedades físicas y químicas, y ampliar su uso en la fabricación de películas y andamios, potenciando las aplicaciones del quitosano en áreas biomédicas y farmacológicas. Los derivados (CH-Leu y CH-Tyr) fueron caracterizados mediante estudios de espectroscopia infrarrojo (ATR-FTIR) para verificar la estructura de los productos modificados y las propiedades térmicas fueron analizadas mediante termogravimetría (TGA). Se realizaron ensayos de solubilidad, donde se observó que los derivados obtenidos son solubles en disoluciones acuosas a valores de pH neutro y alcalino, a diferencia del quitosano que solo es soluble bajo condiciones de pH ácido. La citotoxicidad de los derivados fue analizada mediante ensayos de hemocompatibilidad con eritrocitos humanos. Posteriormente se realizaron membranas a partir de los derivados de CH-Leu y CH-Tyr, y se determinó el ángulo de contacto. El proceso de biodegradabilidad en membranas se estudió a través de procesos de hidrólisis en H2O y buffer fosfato salino (PBS), pH 7,4 a 37ºC durante intervalos de tiempo de 24, 72 y 168 h. Los andamios fueron preparados usando la técnica de electrospinning al preparar una mezcla entre poli(vinil alcohol) (PVA) y los derivados de CH (dada la solubilidad mostrada en agua), y la morfología de las fibras fue estudiada mediante microscopía electrónica de barrido (MEB). En general, los resultados obtenidos por FTIR, TGA y MEB sirvieron como herramientas para verificar la modificación, y estos derivados permiten ampliar las propiedades físicas y químicas del quitosano puro, principalmente en cuanto a su solubilidad, permitiendo que este novedoso biomaterial sea empleado en múltiples aplicaciones, resaltando que pueden ser mezclados con fases poliméricas sintéticas lo cual abre ventanas para el uso de este interesante biopolímero.