Identificação de polímeros de microplásticos encontrados no trato digestivo de peixes do Lago de Amatitlán, Guatemala / Identification of microplastic polymers found in the digestive tract of fish from Lake Amatitlán, Guatemala

O objetivo desta pesquisa foi a identificação, por meio de espectroscopia no infravermelho com transformada de Fourier combinada com reflectância total atenuada (FTIR-ATR), de microplásticos extraídos do trato gastrointestinal de peixes coletados no Lago de Amatitlán, para determinar os principais polímeros e a possível origem da contaminação por esses materiais. Foram analisados 68 microplásticos, correspondendo a 10% do total de microplásticos extraídos. Estes originaram-se de 36 espécimes, sendo 35 da espécie Oreochromis niloticus e um de Parachromis managuensis, dos quais foram analisados de 1 a 5 microplásticos por espécime. Os polímeros identificados foram polipropileno (PP), nylon, polietileno de alta densidade (HDPE), tereftalato de polietileno (PET), látex, poliestireno (PE), polietileno de baixa densidade (LDPE) e poliuretano (PU). O polipropileno (32), o polietileno de alta densidade (13) e o nylon (10) foram os polímeros mais frequentes. Os possíveis itens plásticos que podem ter originado os microplásticos incluem brinquedos, equipamentos de laboratório, baldes, embalagens de alimentos, tubulações, isolamento para cabos, têxteis, cordas e móveis que são produzidos na indústria do plástico, localizada principalmente na vertente sul da cidade da Guatemala. Além disso, as espécies de peixes do presente estudo sustentam pescarias importantes, o que levanta problemas de saúde humana, uma vez que a ingestão de peixes que consomem plásticos tem o potencial de aumentar a carga corporal de substâncias químicas perigosas, pois estas aderem superficialmente aos plásticos no ambiente e são posteriormente bioacumuladas.

The objective of this research was the identification, through Fourier transform infrared spectroscopy combined with attenuated total reflectance (FTIR-ATR), of microplastics extracted from the gastrointestinal tract of fish collected in Lake Amatitlán, to determine the main polymers and the possible origin of contamination by these materials. 68 microplastics were analyzed, corresponding to 10% of the total microplastics extracted. These originated from 36 specimens, 35 of the species Oreochromis niloticus and one of Parachromis managuensis, of which 1 to 5 microplastics per specimen were analyzed. The polymers identified were polypropylene (PP), nylon, high-density polyethylene (HDPE), polyethylene terephthalate (PET), latex, polystyrene (PE), low-density polyethylene (LDPE) and polyurethane (PU). Polypropylene (32), high-density polyethylene (13) and nylon (10) were the most frequent polymers. Possible plastic items that may have caused microplastics include toys, laboratory equipment, buckets, food packaging, pipes, insulation for cables, textiles, ropes and furniture that are produced in the plastics industry, located mainly on the south side of Guatemala City. Furthermore, the fish species in the present study support important fisheries, which raises human health concerns, since the ingestion of fish that consume plastics has the potential to increase the body load of dangerous chemicals, as they adhere superficially to the plastics in the environment and are subsequently bioaccumulated.

In vitro characterization of a novel resin-based restorative material containing alkaline fillers

Abstract Objective: In this study, a comparative evaluation of the physicochemical properties of Cention N and other direct restorative materials was performed. Three restorative materials—a resin-modified glass ionomer (Fuji II LC), an alkasite-based resinous material (Cention N), and a resin composite (Tetric N Ceram)—were characterized in terms of degree of conversion, Knoop hardness number (KHN) ratio, flexural strength, elastic modulus, water sorption, water solubility, microshear bond strength to dentin, immediate microleakage, and radiopacity. Methodology: The microshear bond strength to dentin and microleakage of Cention N were evaluated with and without the application of an adhesive system (Tetric N Bond Universal). A one-way ANOVA test was used to analyze the data in terms of degree of conversion, KHN ratio, water sorption, water solubility, microshear bond strength to dentin, and radiopacity. A two-way ANOVA test (carried out considering the material type and ethanol aging as factors) was used to analyze the data in terms of flexural strength and elastic modulus. The Kruskal-Wallis test was used to statistically analyze the data on microleakage. A significance level of α=0.05 was used for all tests. Results: Fuji II LC was found to have the highest degree of conversion, water sorption, and microleakage, as well as the lowest flexural strength. Cention N had the highest solubility; when used with an adhesive system, it achieved bond strength and microleakage similar to those of the Tetric N Ceram composite. Tetric N Ceram had the highest degree of conversion, KHN ratio, and radiopacity. Conclusion: The properties of Cention N validate its efficacy as an alternative direct restorative material when used in conjunction with an adhesive system.

Autoimmune/inflammatory syndrome induced by adjuvants (ASIA), medical treatment of severe systemic compromise: case report

Case description: A 42-year-old woman with severe pulmonary and mediastinal inflammatory involvement, secondary to infiltration of a silicone-related allogenic material with systemic migration. Clinical findings: The patient developed esophageal and bronchial stenosis, recurrent infections, malnutrition, and respiratory deterioration, making surgical removal of the allogenic material impossible. Treatment and outcome: Clinical and radiological improvement was achieved after treatment with multiple intravenous and oral immunomodulators. Clinical relevance: Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) is a heterogeneous disease resulting from exposure to allogenic substances in a susceptible subject. These substances cause autoimmune or autoinflammatory phenomena. Since ASIA was described ten years ago, its diagnostic criteria are still under discussion, with an uncertain prognosis. The ideal therapy is based on eliminating the causative substance, but this is not always possible. Therefore, it is necessary to start an immunomodulatory treatment, using it in this patient, a scheme that had not been previously reported in the literature.

Descripción del caso: Mujer de 42 años con compromiso inflamatorio pulmonar y mediastinal severo, secundario a infiltración de un material alogénico relacionado con la silicona con migración sistémica. Hallazgos clínicos: La paciente desarrolló estenosis esofágica y bronquial, infecciones recurrentes, desnutrición y deterioro respiratorio, imposibilitando la extracción quirúrgica del material alogénico. Tratamiento y resultado: Mejoría clínica y radiológica lograda tras un tratamiento con múltiples inmunomoduladores intravenosos y orales. Relevancia clínica: El síndrome autoinmune / inflamatorio inducido por adyuvantes (ASIA) es una enfermedad heterogénea que resulta de la exposición a sustancias alógenas en un sujeto con susceptibilidad genética. Estas sustancias inducen fenómenos autoinmunitarios o autoinflamatorios. Desde que ASIA fue descrito hace 10 años, sus criterios diagnósticos continúan en discusión, con un pronóstico incierto. El tratamiento idóneo se basa en eliminar la sustancia causante, pero no siempre es posible, por lo cual se hace necesario iniciar un tratamiento inmunomodulador, empleándose en esta paciente un esquema que no había sido reportado previamente en la literatura.

Formulation and evaluation of Buccal mucoadhesive tablets of diclofenac sodium using 23 factorial designs

Buccal tablets

Diclofenac sodium

Drug release

Mucoadhesion

Mucoadhesive tablets

Release kinetics

Carbomer hemorrhoid gel for the treatment of second-degree internal hemorrhoid bleeding / 中国基层医药

Objective:To investigate the clinical efficacy of carbomer hemorrhoid gel in the treatment of second-degree internal hemorrhoid bleeding.Methods:A total of 160 anorectal outpatients with second-degree internal hemorrhoid bleeding who received treatment in Zhuhai Hospital of Integrated Traditional Chinese and Western Medicine from January 2017 to January 2021 were included in this study. They were randomly divided into an observation group and a control group ( n = 80/group). In the observation group, carbomer hemorrhoid gel was used to plug the anus, while in the control group, a hemorrhoid suppository was used to plug the anus. All patients were treated for 7 days. Clinical efficacy was compared between the two groups. Results:After 4 days of treatment, the bleeding score in the observation group was lower than that in the control group [1(0) point vs. 2(1) points, Z = -6.70, P < 0.05). After 7 days of treatment, the bleeding score in the observation group was significantly lower than that in the control group [0(1) point vs. 1(1) point, Z = -4.73, P < 0.05]. After 4 days of treatment, there was no significant difference in the size score of the hemorrhoids between the two groups ( P > 0.05). After 4 days of treatment, the size score of hemorrhoids in the control group did not differ significantly compared with before treatment ( P > 0.05). After 4 days of treatment, the size score of hemorrhoids in the observation group differed significantly compared with before treatment ( Z = -3.16, P < 0.05). After 7 days of treatment, the size score of the hemorrhoids in the observation group was lower than that in the control group [1(1) point vs. 1(0) point, Z = -4.48, P < 0.05]. The total response rate in the observation group was significantly higher than that in the control group [97.5% (78/80) vs. 75% (60/80), Z = -4.50, P < 0.05]. Conclusion:Carbomer hemorrhoid gel is a new drug used to treat hemorrhoids. It has a new dosage form, has no stimulation to the rectum, and is safe to use. Carbomer hemorrhoid gel is highly effective on second-degree internal hemorrhoid bleeding and deserves clinical popularization.

3D Raman mapping as an analytical tool for investigating the coatings of coated drug particles / 药物分析学报

The properties of dry-coated paracetamol particles(fast-dissolving model drug)with carnauba wax particles as the coating agent(dissolution retardant)were investigated.Raman mapping technique was used to non-destructively examine the thickness and homogeneity of coated particles.The results showed that the wax existed in two forms on the surface of the paracetamol particles,forming a porous coating layer:i)whole wax particles on the surface of paracetamol and glued together with other wax surface particles,and ii)deformed wax particles spread on the surface.Regardless of the final particle size fraction(between 100 and 800 μm),the coating thickness had high variability,with average thickness of 5.9±4.2 μm.The ability of carnauba wax to decrease the dissolution rate of paracetamol was confirmed by dissolution of powder and tablet formulations.The dissolution was slower for larger coated particles.Tableting further reduced the dissolution rate,clearly indicating the impact of subsequent formulation processes on the final quality of the product.

Progress in stimuli-responsive molecularly imprinted polymers for enrichment analysis of trace components in traditional Chinese medicine / 中国中药杂志

Molecularly imprinted polymers demonstrate outstanding performance in the research on trace ingredients because of their high selectivity. Stimuli-responsive molecularly imprinted polymers(STR-MIPs) with the introduction of different responsive groups on the basis of traditionally imprinted materials can undergo reversible transformations when exposed to external stimuli such as temperature, magnetism, pH or light. Such responsiveness, combined with the specific recognition, endows STR-MIPs with excellent perfor-mance in trace component studies. Traditional Chinese medicine(TCM) contains complex components with trace content, and thus STR-MIPs have broad application prospects in the enrichment analysis of trace components in TCM. This paper elaborates on the application of STR-MIPs in the enrichment analysis of trace components in TCM from the perspectives of different stimuli, summarized relevant research achievements in the recent five years to broaden the application fields of molecular imprinting, and proposed a few opi-nions about their future development.

Advances on the production of organic acids by yeast / 生物工程学报

Organic acids are organic compounds that can be synthesized using biological systems. They often contain one or more low molecular weight acidic groups, such as carboxyl group and sulphonic group. Organic acids are widely used in food, agriculture, medicine, bio-based materials industry and other fields. Yeast has unique advantages of biosafety, strong stress resistance, wide substrate spectrum, convenient genetic transformation, and mature large-scale culture technology. Therefore, it is appealing to produce organic acids by yeast. However, challenges such as low concentration, many by-products and low fermentation efficiency still exist. With the development of yeast metabolic engineering and synthetic biology technology, rapid progress has been made in this field recently. Here we summarize the progress of biosynthesis of 11 organic acids by yeast. These organic acids include bulk carboxylic acids and high-value organic acids that can be produced naturally or heterologously. Finally, future prospects in this field were proposed.

Efficiency analysis of commercial polymeric membranes for bone regeneration in rat cranial defects

Purpose: To evaluate the in vivo efficiency of commercial polymeric membranes for guided bone regeneration. Methods: Rat calvarial critical size defects was treated with LuminaCoat (LC), Surgitime PTFE (SP), GenDerm (GD), Pratix (PR), Techgraft (TG) or control (C-) and histomorphometric analysis determined the percentage of new bone, connective tissue and biomaterial at 1 or 3 months. Statistical analysis used ANOVA with Tukey's post-test for means at same experimental time and the paired Student's t test between the two periods, considering p < 0.05. Results: New bone at 1 month was higher for SP, TG and C-, at 3 months there were no differences, and between 1 and 3 months PR had greater increase growthing. Connective tissue at 1 month was higher for C-, at 3 months for PR, TG and C-, and between 1 and 3 months C- had sharp decline. Biomaterial at 1 month was higher for LC, in 3 months for SP and TG, and between 1 and 3 months, LC, GD and TG had more decreasing mean. Conclusion: SP had greater osteopromotive capacity and limitation of connective ingrowth, but did not exhibit degradation. PR and TG had favorable osteopromotion, LC less connective tissue and GD more accelerated biodegradation.

Fabrication of 1,4-alpha-D-glucan glucanohydrolase holding Gel-Scaffolds using Agar-Agar, a natural polysaccharide and Polyacrylamide, a synthetic organic polymer for continuous liquefaction of starch

1,4-alpha-D-glucan glucanohydrolase is among the most widely used commercial hydrolytic enzymes acting randomly on the glycosidic linkages of starch resulting in its saccharification and liquefaction. Its applicability in different industries can be improved by enhancing its stability and reusability. Therefore, in the present study attempts have been made to enhance the industrial applicability of 1,4-alpha-D-glucan glucanohydrolase from Bacillus subtilis KIBGE-HAR by adapting immobilization technology. The study developed mechanically stable, enzyme containing gel-frameworks using two support matrices including agar-agar, a natural polysaccharide and polyacrylamide gel, a synthetic organic polymer. These catalytic gel-scaffolds were compared with each other in terms of kinetics and stability of entrapped 1,4-α-D-glucan glucanohydrolase. In case of polyacrylamide gel, Km value for immobilized enzyme increased to 7.95 mg/mL, while immobilization in agar-agar resulted in decreased Km value i.e 0.277 mg/mL as compared to free enzyme. It was found that immobilized enzyme showed maximum activity at 70 °C in both the supports as compared to free enzyme having maximum activity at 60 °C. Immobilized 1,4-α-D-glucan glucanohydrolase exhibited no change in optimal pH 7.0 before and after entrapment in polyacrylamide gel and agar-agar. The enzyme containing gel-scaffold was found suitable for repeated batches of starch liquefaction in industrial processes. Agar-agar entrapped 1,4-α-D-glucanglucanohydrolase was capable to degrade starch up to seven repeated operational cycles whereas polyacrylamide entrapped enzyme conserved its activity up to sixth operational cycle.

Comparison of shear bond strength and color reproduction of two different high-performance polymers veneered with two different thicknesses of resin composite: an in-vitro study / Comparação da resistência ao cisalhamento e reprodução de cor de dois diferentes polímeros de alto desempenho revestidos com duas diferentes espessuras de resina composta: um estudo in vitro

Objective: to evaluate the effect of material type and veneer thickness on the final color and shear bond strength of PEEK bilayered restorations. Material and Methods: sixty-four square-shaped core specimens (7×7×2), were fabricated by CAD/CAM technology from two high-strength polymers, BioHPP (High-Performance Polymer, group B n=32), and Pekkton® ivory (PolyEtherKetoneKetone, group P n=32) then were veneered with resin composite (crea.lign dentin A3). Specimens from each group were divided (n=16) according to the veneer layer thickness (0.5 & 1 mm), then according to the test applied (n=8), either ΔE or shear bond strength (SBS). Specimen surfaces were treated according to the manufacturer's instructions. Specimens were veneered according to the manufacturer's instructions.The mode of failure was evaluated under a stereomicroscope at 40 x magnification after the shear bond strength test. Results: data showed parametric distribution and variance homogeneity and were analyzed using two-way ANOVA. The significance level was set at p<0.05 for all tests. Statistical analysis was performed with the R statistical analysis software version 4.3.1.Results of two-way ANOVA showed that material types and veneer thicknesses had an individual significant effect on the color change. For the shear bond strength, only the sample thickness (1mm) had a significant effect (p=0.033). The majority of samples in different groups presented a mixed failure mode with all the differences being not statistically significant (p>0.05). Conclusion: the thickness of the resin composite veneer can significantly affect the final esthetic outcome and shear bond strength of a bilayered restoration.(AU)

Objetivo: avaliar o efeito do tipo de material e da espessura do revestimento na cor final e na resistência ao cisalhamento de restaurações em duas camadas de PEEK. Material e Métodos: foram fabricados 64 espécimes com núcleo de formato quadrado (7x7x2) usando tecnologia CAD/CAM a partir de dois polímeros de alta resistência, BioHPP (Polímero de Alto Desempenho, grupo B n=32) e Pekkton ivory (Polieterecetona cetona, grupo P n=32), que foram então revestidos com resina composta (crea.lign dentin A3). Os espécimes de cada grupo foram divididos (n=16) de acordo com a espessura do revestimento (0,5 e 1 mm), e depois de acordo com o teste aplicado (n=8), seja ΔE ou resistência ao cisalhamento (SBS). As superfícies dos espécimes foram tratadas de acordo com as instruções do fabricante. Os espécimes foram revestidos de acordo com as instruções do fabricante. O modo de falha foi avaliado sob um estereomicroscópio com ampliação de 40x após o teste de resistência ao cisalhamento. Resultados: os dados apresentaram distribuição paramétrica e homogeneidade de variância e foram analisados por ANOVA de duas vias. O nível de significância foi estabelecido em p<0,05 para todos os testes. A análise estatística foi realizada com o software de análise estatística R, versão 4.3.1. Os resultados da ANOVA de duas vias mostraram que os tipos de materiais e as espessuras do revestimento tiveram um efeito significativo individual na mudança de cor. Para a resistência ao cisalhamento, apenas a espessura da amostra (1mm) teve um efeito significativo (p=0,033). A maioria das amostras em diferentes grupos apresentou um modo de falha misto, com todas as diferenças não sendo estatisticamente significativas (p>0,05). Conclusão:a espessura do revestimento de resina composta pode afetar significativamente o resultado estético final e a resistência ao cisalhamento de uma restauração em duas camadas.(AU)

Effect of different materials for temporary removable partial denture: an in vitro study on surface roughness and fracture resistance / Efeito de diferentes materiais para confecção de prótese parcial removível provisória: um estudo in vitro sobre rugosidade superficial e resistência à fratura

ABSTRACT The use of removable partial dentures is considered a common and inexpensive treatment option to rehabilitate edentulous areas. The aim of this study was to evaluate the effect of different materials for provisional removable partial dentures, an in vitro study on surface roughness and fracture resistance. Thermopolymerizable acrylic resin and thermoplastic resin specimens with dimensions of 10 x 10 x 2 mm (blocks) (n=10) and with dimensions of 65 x 20 x 3 mm (bars) (n=10 were analyzed for their surface roughness (Ra) and three-point flexural strength test. All specimens were subjected to oven aging for 60 days at 37°C±0.5°C in distilled water. The statistical analysis was performed with a significance level of 5%, and the surface roughness data were submitted to the Two-way Anova statistical test (P < 0.05) and the mechanical strength data were subjected to One-way Anova statistical test (P < 0.05). For roughness, the factor resin type (P = 0.000) and the factor aging (P = 0.000) were statically significant, as well as showing interaction (P = 0.228). The Thermopolymerizable acrylic resin had the lowest mean roughness values compared to the thermoplastic resin and showed no statistical difference after aging. The same scenario was repeated for flexural strength values; Thermopolymerizable acrylic resin was statistically superior to thermoplastic resin (P = 0.000). Thermopolymerized acrylic resin showed lower surface roughness values and higher flexural strength values compared to thermoplastic resin.

RESUMO O uso de próteses parciais removíveis é considerado uma opção de tratamento comum e de baixo custo para reabilitar áreas edêntulas. O objetivo deste estudo foi avaliar o efeito de diferentes materiais para próteses parciais removíveis provisórias, um estudo in vitro sobre rugosidade superficial e resistência à fratura. Espécimes de resina acrílica termopolimerizável e de resina termoplástica com dimensões de 10 x 10 x 2 mm (blocos) (n = 10) e de 65 x 20 x 3 mm (barras) (n = 10) foram analisados em rugosidade superficial média (Ra) e teste de resistência à flexão de três pontos. Todos os espécimes foram submetidos ao envelhecimento em estufa por 60 dias a 37 ° C ± 0,5 ° C em água destilada. A análise estatística se deu com nível de significância de 5%, e os dados de rugosidade superficial foram submetidos ao teste estatístico Anova dois fatores (P <0,05) e os dados de resistência mecânica foram submetidos ao teste estatístico Anova um fator (P <0,05). Para rugosidade, o fator tipo resina (P = 0,000) e o fator envelhecimento (P = 0,000) foram estatisticamente significantes, além de apresentar interação (P = 0,228). A resina acrílica termopolimerizável apresentou menores valores médios de rugosidade em relação à resina termoplástica e não apresentou diferença estatística após envelhecimento. O mesmo cenário foi repetido para valores de resistência à flexão; a resina acrílica termopolimerizável foi estatisticamente superior à resina termoplástica (P = 0,000). A resina acrílica termopolimerizada apresentou menores valores de rugosidade superficial e maiores valores de resistência à flexão em relação à resina termoplástica.

Instrumento de avaliação prática empírica de materiais termoplásticos para órteses / Empirical practical evaluation instrument for thermoplastic materials for orthoses

Resumo Introdução Após o advento dos termoplásticos de baixa temperatura, sua prevalência na confecção de órteses para membros superiores é identificada por vários autores. A compreensão de suas propriedades, por parte do terapeuta ocupacional e de outros profissionais que atuam na área, é importante no processo de seleção do termoplástico, que segue uma lógica para combinar as características do material à função desejável para cada órtese. Objetivos Sistematizar as características dos termoplásticos de baixa temperatura e, a partir disso, elaborar um instrumento para realizar testes práticos empíricos com os materiais a fim de estabelecer critérios para o seu manuseio e avaliação. Método Pesquisa de caráter exploratório, constituindo a criação de procedimentos de teste e, consequentemente, a elaboração de um instrumento de avaliação de abordagem qualitativa e que valoriza a experiência prática do profissional, que manipula o material e avalia cada requisito. Resultados O instrumento criado contempla 14 caraterísticas do material, acompanhadas de uma definição, um procedimento com recomendações para o teste prático e um campo destinado ao preenchimento das alternativas de resposta. Conclusão O instrumento considera características importantes a serem verificadas durante a avaliação dos materiais e poderá direcionar o olhar e os registros do profissional, auxiliando o nas decisões clínicas. Isso será importante para melhorar a qualidade das órteses e de outros dispositivos de Tecnologia Assistiva confeccionados com esse grupo de materiais. Além disso, a sistematização da avaliação prática dos materiais termoplásticos poderá auxiliar no desenvolvimento de estudos da área da saúde e de pesquisas envolvendo materiais para órteses.

Abstract Introduction After the advent of low-temperature thermoplastics, their prevalence in the manufacture of orthoses for upper limbs has been identified by several authors. The understanding of their properties by occupational therapists and other professionals working in this field is important in the process of selecting the thermoplastic, which follows a logic to match the material's characteristics to the desired function for each orthosis. Objectives Systematize the characteristics of low-temperature thermoplastics and, from that, develop an instrument for carrying out practical empirical tests with the materials, to establish criteria for their handling and evaluation. Method Exploratory study consisting of the creation of testing procedures and, consequently, the development of a qualitative assessment instrument that values ​​the practical experience of the professional who handles the material and evaluates each requirement. Results The created instrument includes 14 material characteristics, accompanied by a definition, a procedure with recommendations for the practical testing, and a field for filling in response alternatives. Conclusions The instrument considers important characteristics to be verified during the evaluation of materials and can direct the professional's observations and records, aiding in clinical decision-making. This will be important to improve the quality of orthoses and other assistive technology devices made with these thermoplastics. In addition, the systematization of the practical evaluation of thermoplastic materials can assist in the development of health studies and research involving materials for orthoses.

Interplay between resin cements and surface-treated Poly-Ether-Ether-Ketone (PEEK): effect of aging

Aim: This study assessed the effect of thermal aging on the interfacial strength of resin cements to surface-treated PEEK. Methods: Ninety-six PEEK blocks were allocated into 4 groups (n=24), according to following surface treatments: SB - sandblasting with aluminum oxide; SA - acid etched with 98% sulfuric acid; CA ­ coupling agent (Visio.link, Bredent) and CO - control group (untreated). Surface roughness (Ra) was measured and one cylinder (1-mm diameter and height) of Rely-X Ultimate - ULT (3M/ESPE) and another one of Panavia V5 - PAN (Kuraray) were constructed on the treated or untreated PEEK surfaces. Half of the samples of each group were thermal aged (1,000 cycles). Samples were tested at a crosshead speed of 1 mm/min in shear mode (µSBS). Ra and µSBS data were compared using one- and three-way ANOVA, respectively, and Tukey's tests. Results: SA and SB samples had the roughest surfaces, while CA the smoother (p<0.001). Thermal aging reduced µSBS regardless the surface treatment and resin cement used. There was interaction between surface treatment and resin cement (p <0.001), with ULT showing higher µSBS values than PAN. SA provided higher µSBS than SB for both resin cements, while for CA µSBS was higher (PAN) or lower than SB (ULT). Conclusion: Aging inadvertently reduces interfacial strength between PEEK and the resin cements. If ULT is the resin cement of choice, reliable interfacial strength is reached after any PEEK surface treatment. However, if PAN is going to be used only SA and CA are recommended as PEEK treatment

Preliminary application evaluation of polydopamine nano-carriers labeled with multiple radionuclides / 中华核医学与分子影像杂志

Objective:To prepare nanoprobes by using polydopamine (PDA) as a carrier which is modified with the sonosensitizer protoporphyrin Ⅸ (PpⅨ) and labeled with 131I, 99Tc m or 177Lu, and to explore the value of these new nanoprobes in diagnosis and combination therapy of breast cancer. Methods:PDA particles were synthesized by aqueous oxidation, and a layer of polyethylene glycol (PEG) and PpⅨ were modified on the surface to product PDA-PEG-PpⅨ. Then the nuclides 131I, 99Tc m and 177Lu were labeled on PDA, respectively, and the labeling yield and stability were determined. The cytotoxicity test was conducted by comparing the viabilities of 4T1 tumor cells in free 131I group and 131I-PDA-PEG-PpⅨ group. The 4T1 cells were divided into 7 groups according to different treatment methods: PDA-PEG-PpⅨ group, PDA-PEG-PpⅨ+ photothermal therapy (PTT) group, PDA-PEG-PpⅨ+ sonodynamic therapy (SDT) group, 131I-PDA-PEG-PpⅨ+ PTT group, 131I-PDA-PEG-PpⅨ+ SDT group, 131I-PDA-PEG-PpⅨ+ PTT+ SDT group (100 μg/ml PDA-PEG-PpⅨ, 925 kBq/ml 131I), and the control group (DMEM culture medium). The cell viabilities of those groups were compared to evaluate the therapeutic effect. 4T1 tumor bearing mouse models were established, then 99Tc m-PDA-PEG-PpⅨ was injected through the tail vein (29.6 MBq) or intratumorally (14.8 MBq) to perform gamma imaging. The independent-sample t test and one-way analysis of variance were used for data analysis. Results:The PDA particles were uniform in size, with a particle size of (160.0±1.5) nm. They had a good photothermal conversion effect. A characteristic peak consistent with PpⅨ (400 nm) appeared in the UV-Vis absorption spectrum of PDA-PEG-PpIX. In the cytotoxicity test, when the radioactivity was 1.850 or 3.700 or 7.400 MBq/ml, the cell viabilities of free 131I group and 131I-PDA-PEG-PpⅨ group were significantly different ((72.18±6.57)% vs (86.07±5.17)%, (59.31±9.06)% vs (80.85±4.21)%, (42.90±1.30)% vs (72.99±5.73)%; t values: 3.71, 4.82, 11.46, P values: 0.006, 0.001, <0.001). The 131I-PDA-PEG-PpⅨ+ PTT+ SDT combination therapy had a better killing effect on 4T1 tumor cells than the combination of 131I-PDA-PEG-PpⅨ+ PTT and 131I-PDA-PEG-PpⅨ+ SDT (cell viabilities: (10.09±2.50)% vs (16.04±2.63)%, (28.65±4.72)%; F=351.66, P<0.001). In vivo imaging showed that 99Tc m-PDA-PEG-PpⅨ was stable in mouse models and could be effectively enriched in tumors. Conclusions:A multifunctional nanoprobe based on PDA is successfully prepared. The radionuclide labeling method is simple and effective, with a good stability. 131I-PDA-PEG-PpⅨ can kill 4T1 cells efficiently. 99Tc m-PDA-PEG-PpⅨ has an obvious tumor concentration effect in mouse models.

Evaluation, preparation, and description of chitosan nanoparticles, as well as improving rivaroxaban bioavailability

The aim of the present study is the Evaluation, preparation, and description of chitosan nanoparticles and bioavilibility enhancement of rivaroxaban. Preparation of Rivaroxaban nanoparticles (RB-NPs) were prepared by the ionic gelation method. Different parameters were studied for evaluation, Preparation & description of nanoparticles. The results of the present study showed that the formulation F7 showed the significant results for all the selected parameter as compared to the other formulations. The formulation F1, F5, and F6 showed the highest production yield (52.5, 52.35, and 52.35% respectively) and F7 showed the significant production yield (51.85%), zeta-potential (23.63 mV), entrapment efficiency (99.87), particle size (316.12±2.14 nm) and poly disparity index (0.32). Nanoparticles are solid colloidal drug carriers ranging from 10—1000 nm in diameter and are composed of synthetic, natural or semi-synthetic polymers encapsulating the drug molecule.

Efeitos do laser de baixa intensidade em osteoblastos cultivados em arcabouços nanofibrosos de ácido polilático / Effects of low-intensity laser on osteoblasts cultured on polylactic acid nanofibrous scaffolds

A engenharia de tecidos ósseos é um ramo importante da medicina regenerativa e envolve o desenvolvimento de arcabouços com composição e arquitetura favoráveis à integração celular, além do estudo de fatores capazes de promover a adesão e proliferação celular, incluindo estímulos químicos e biofísicos. O objetivo do estudo foi avaliar a utilização do laser de baixa intensidade (LBI) como uma ferramenta para promover a bioestimulação in vitro de células osteoblásticas cultivadas em arcabouços nanofibrosos de ácido polilático (PLA). Os arcabouços foram produzidos pela técnica de eletrofiação e caracterizados quanto à molhabilidade, composição pela espectroscopia no infravermelho por transformada de Fourier (FTIR), morfologia da superfície por microscópica eletrônica de varredura (MEV), caracterização termogravimétrica (TGA), calorimetria diferencial exploratória (DSC) e cristalinidade por difração de raios-X (DRX). Os ensaios biológicos foram conduzidos com osteoblastos da linhagem OFCOL II cultivados na superfície dos arcabouços e submetidos ou não (grupo controle) a irradiação com laser diodo InGaAIP na potência de 30 mW, nas doses de 1, 4 e 6 J/cm² e nos comprimentos de onda de 660 nm (grupos V1, V4, V6, respectivo as doses) e 780 nm (grupos I1, I4 e I6, respectivo as doses). Os efeitos do LBI na proliferação dos osteoblastos foram avaliados através do método bioquímico Alamar Blue, nos intervalos de 24, 48 e 72h, enquanto a viabilidade e a morfologia celular foram analisadas no intervalo de 72h, através do ensaio Live/Dead e da microscopia eletrônica de varredura (MEV), respectivamente. Os dados do ensaio bioquímico de Alamar Blue mostraram uma maior proliferação celular nos grupos V6 em todos os intervalos analíticos em comparação ao grupo controle (p<0,05). Outras diferenças entre o grupo controle e irradiados foram encontradas apenas nos intervalos de 48h e 72h para V1, e para o grupo IV6 em 72h. O ensaio Live/Dead revelou um aumento na viabilidade celular nos grupos trados com LBI, sendo significativamente maior no grupo V1 quando comparado ao grupo controle. A análise por MEV mostrou adequada interação dos osteoblastos aos arcabouços, com o corpo celular se espalhando ao longo do eixo da nanofibra e a presença de contatos físicos mais evidentes, através da formação de ligação por meio de filopódios e lamelipódios, nos grupos V1, V6 e I6. Em conjunto, os dados do presente trabalho mostraram que o LBI promove a bioestimulação de osteoblastos cultivados sobre nanofibras de PLA, o que aponta para o seu uso potencial nas técnicas de engenharia tecidual óssea, sobretudo no que se refere ao uso do comprimento de onda de 660 nm, a qual apresentou grupos com mais resultados significativos (AU).

Bone tissue engineering is a relevant branch of regenerative medicine and involves the development of scaffolds with composition and architecture favorable to cell integration, in addition to studying factors capable of promoting cell adhesion and proliferation, including chemical and biophysical stimuli. The study aimed to evaluate the use of low-level laser irradiation (LLLI) to promote in vitro biostimulation of osteoblastic cells cultured on polylactic acid (PLA) nanofibrous scaffolds. The scaffolds were produced by the electrospinning technique and characterized in terms of wettability, composition by Fourier transform infrared spectroscopy (FTIR), surface morphology by scanning electron microscopy (SEM), thermogravimetric characterization (TGA), differential scanning calorimetry (DSC) and crystallinity by Xray diffraction (XRD). The biological assays were conducted with osteoblasts of the OFCOL II lineage cultured on the surface of the scaffolds and submitted or not (control group) to irradiation with InGaAIP diode laser, power of 30 mW, with doses of 1, 4 and 6 J/cm² and wavelengths of 660 nm (groups V1, V4, V6, respectively doses) and 780 nm (groups I1, I4 and I6, respectively doses). The effects of LLLT from the perspective of osteoblasts were evaluated using the biochemical method Alamar Blue assay, at intervals of 24, 48 and 72h, while cell viability and morphology were observed at 72h, using the Live/Dead assay and electron microscopy. scan (SEM), respectively. The Alamar Blue assay data showed more significant cell proliferation in groups in the V6 groups at all analytical intervals compared to the control group (p<0.05). Other differences between the control and irradiated groups were found only at intervals of 48h and 72h for V1, and for group IV6 at 72h. The Live/Dead assay revealed an increase in cell viability in the groups treated with LLLT, being significantly higher in the V1 group when compared to the control group. SEM analysis showed adequate interaction between osteoblasts and scaffolds, with the cell body spreading along the nanofiber axis and the presence of more evident physical contacts, through the formation of bonds through filopodia and lamellipodia, in groups V1, V6 and I6. Together, the data from the present study observed that LLLT promotes the biostimulation of osteoblasts cultured on PLA nanofibers, which pointed to its potential use in bone tissue engineering techniques, especially with regard to the use of the wavelength of 660 nm, which presented groups with more significant results (AU).

Eletrofiação aplicada a cicatrização de feridas: revisão de literatura / Electrospinning applied to wound healing: literature review / Electroalambre aplicado a la cicatrización de heridas: revisión de la literatura

feridas correspondem a interrupção da continuidade da pele, com a perda de uma ou mais camadas do tecido cutâneo. Curativos tradicionalmente aplicados em feridas cutâneas buscam principalmente fornecer uma barreira de proteção e permitir o desenvolvimento dos eventos celulares e bioquímicos que compreendem a cicatrização. Objetivou-se com este estudo apresentar sob a forma de revisão de literatura narrativa os principais eventos relacionados ao processo de reparo tecidual da pele, bem como abordar a aplicabilidade da técnica de eletrofiação no desenvolvimento de curativos funcionais biocompatíveis. Foram selecionados artigos voltados à caracterização dos eventos chave ocorridos a nível tecidual durante a cicatrização e, na sequência, buscou-se artigos voltados à produção, caracterização e aplicação de filmes nanoeletrofiados com ênfase na utilização de biopolímeros e substâncias bioativas. Observou-se que a maioria dos trabalhos recentes, voltados a pesquisa de base, descrevem a resposta vascular como o principal evento do processo cicatricial, sendo responsável pelas etapas que se desenrolam a seguir, que compreendem as fases inflamatória, proliferativa e de remodelamento, classicamente já descritas. Os curativos funcionais baseados em polímeros eletrofiados apresentam resultados superiores quanto testados in vitro e in vivo. As características morfoestruturais mimetizam a matriz extracelular e podem atuar em tecidos alvo como dispositivos de entrega de substâncias. Conclui-se que a atualização e reorganização de conceitos relativos à cicatrização podem contribuir no desenvolvimento de inovações, como os curativos produzidos por eletrofiação. Embora promissora, as desvantagens da técnica encontram-se principalmente no processo de obtenção e disponibilidade, que limitam a aplicação clínica em escala comercial.

Wounds correspond to the interruption of skin continuity, with the loss of one or more layers of skin tissue. Dressings traditionally applied to cutaneous wounds mainly seek to provide a protective barrier and allow the development of cellular and biochemical events that comprise healing. The objective of this study was to present, in the form of a narrative literature review, the main events related to the skin tissue repair process, as well as to address the applicability of the electrospinning technique in the development of biocompatible functional dressings. Articles focused on the characterization of the key events that occurred at the tissue level during healing were selected and, subsequently, articles focused on the production, characterization and application of nanoelectrospun films with emphasis on the use of biopolymers and bioactive substances were sought. It was observed that most recent works, focused on basic research, describe the vascular response as the main event of the healing process, being responsible for the steps that follow, which include the inflammatory, proliferative and remodeling phases, classically already described. Functional dressings based on electrospun polymers show superior results when tested in vitro and in vivo. The morphostructural features mimic the extracellular matrix and can act in target tissues as substance delivery devices. It is concluded that the updating and reorganization of concepts related to healing can contribute to the development of innovations, such as dressings produced by electrospinning. Although promising, the technique's disadvantages lie mainly in the process of obtaining and availability, which limit clinical application on a commercial scale.

Las heridas corresponden a la interrupción de la continuidad de la piel, con la pérdida de una o más capas de tejido cutáneo. Los apósitos aplicados tradicionalmente a las heridas cutáneas buscan principalmente proporcionar una barrera protectora y permitir el desarrollo de los eventos celulares y bioquímicos que comprenden la curación. El objetivo de este estudio fue presentar en forma de revisión bibliográfica narrativa los principales acontecimientos relacionados con el proceso de reparación tisular de la piel, así como abordar la aplicabilidad de la técnica de electrodeposición en el desarrollo de apósitos funcionales biocompatibles. Se seleccionaron artículos dirigidos a la caracterización de los eventos chave ocurridos a nivel técnico durante la cicatrización y, a continuación, se buscaron artículos dirigidos a la producción, caracterización y aplicación de películas nanoelectrofíricas con énfasis en el uso de biopolímeros y sustancias bioativas. Se observa que la mayoría de los trabajos recientes, realizados en la investigación de base, describen la respuesta vascular como el principal evento del proceso cicatricial, siendo responsable de las etapas que se desarrollan a continuación, que comprenden las fases inflamatoria, proliferativa y de remodelación, clásicamente descritas. Los apósitos funcionales basados en polímeros electro-tejidos presentan resultados superiores cuando se prueban in vitro e in vivo. Las características morfoestruturales mimetizan la matriz extracelular y pueden actuar en tejidos alvos como dispositivos de entrega de sustancias. Se concluye que la actualización y la reorganización de los conceptos relativos a la cicatrización pueden contribuir al desarrollo de innovaciones, como las curativas producidas por la electrofagia. Aunque es prometedora, las desventajas de la técnica radican principalmente en el proceso de obtención y la disponibilidad, que limitan la aplicación clínica a escala comercial.

A REVIEW ON ECOFRIENDLY POLYMERS AND THEIR POTENTIAL APPLICATIONS IN BIOMEDICAL SCIENCES

Eco-friendly polymers are biodegraded by microorganisms, making it easy to transform them into safer, more straightforward forms. These biodegradable materials can be used in a variety of industries, including medicine, agriculture, drug release research, food and medication packaging, and artificial skin grafts. It prevents environmental accumulation and cannot result in pollution of the land, air, or water

Desempeño Mecánico de Compuestos de Madera Plástica de Matriz Poliolefínica / Mechanical performance of polyolefinic wood plastic composites / Desempenho mecânicos de compostos de Madeira Plástica de Matriz Poliolefina

Resumen Los polímeros termoplásticos, pueden ser mezclados con diferentes tipos de cargas con el propósito de mejorar su rendimiento físico-mecánico, al mismo tiempo que permiten en muchos casos, generar soluciones a problemáticas ambientales como por ejemplo la disposición final de residuos de madera. Los compuestos de madera plástica son productos elaborados mediante la incorporación de fibras o partículas de madera en la matriz polimérica, donde la interacción entre los dos materiales (nula o con acople) es clave para lograr un adecuado desempeño del producto final. En esta revisión se establecen las matrices poliméricas y los tipos de maderas empleadas comúnmente en la elaboración de productos de madera plástica, al mismo tiempo que se definen los tratamientos previos que deben ser realizados tanto en la madera como en el polímero con el propósito de mejorar la compatibilidad de los dos materiales, y de esta manera mejorar propiedades como la absorción de agua, la resistencia a la descomposición, a la intemperie y el desempeño mecánico. En cuanto a las propiedades mecánicas, al adicionar un contenido de madera en el polímero se modifica la rigidez del material polimérico y la resistencia en tensión, flexión e impacto; sin embargo, se establece que es clave el uso de agentes funcionalizantes para que el efecto de la incorporación de la madera en polímero sea positivo. Finalmente se estudian las nuevas tendencias en el uso de diferentes tipos de residuos y matrices poliméricas para la elaboración de maderas plásticas.

Abstract Polymeric materials, especially thermoplastics, can be mixed with different types of fillers to improve their physical-mechanical performance, at the same time they allow, in many cases, to generate solutions to environmental problems such as the final disposal of wood waste. The plastic wood composites are products made by incorporating wood fibers in the polymer matrix, where the interaction between the two materials is key to achieve an adequate performance of the final product. This review establishes the polymer matrices and the types of wood commonly used in the production of plastic wood products, at the same time defining the previous treatments that must be carried out in the wood and in the polymer to improve the compatibility of the two materials, and in this way improve properties such as water absorption, resistance to decomposition, resistance to weathering and mechanical performance. Related to the mechanical properties, adding the wood fibers in the polymer modifies the rigidity of the polymeric material and the resistance in tension, bending and impact; however, it is established that the use of functionalizing agents is a fundamental key to improve the effect of wood incorporation into the polymer matrix. Finally, the new trends in the use of different types of waste and polymeric matrices to produce plastic wood are studied.

Resumo Os materiais poliméricos, principalmente os termoplásticos, podem ser misturados a diferentes tipos de cargas para melhorar seu desempenho físico-mecânico, ao mesmo tempo que, em muitos casos, permitem gerar soluções para problemas ambientais como a destinação final de resíduos. madeira. Os compósitos madeira-plástico são produtos obtidos pela incorporação de fibras de madeira à matriz polimérica, onde a interação entre os dois materiais é fundamental para um desempenho adequado do produto final. Nesta revisão, são estabelecidas as matrizes poliméricas e os tipos de madeira comumente utilizados na produção de produtos plásticos de madeira, ao mesmo tempo em que são definidos os tratamentos anteriores que devem ser realizados na madeira e no polímero para melhorar a compatibilidade dos dois materiais, e desta forma melhorar propriedades como absorção de água, resistência à decomposição, intempéries e desempenho mecânico. Em relação às propriedades mecânicas, ao adicionar as fibras de madeira ao polímero, a rigidez do material polimérico e a resistência à tração, flexão e impacto são modificadas; porém, está estabelecido que o uso de agentes funcionalizantes é fundamental para que o efeito da incorporação da madeira no polímero seja positivo. Por fim, são estudadas as novas tendências no uso de diferentes tipos de resíduos e matrizes poliméricas para a produção de madeira plástica.