Starch Modified With Chitosan and Reinforced With Feather Keratin Materials Produced by Extrusion Process: An Alternative to Starch Polymers

They also reached up to 3800% and 3150% in maximum strength, respectively, compared to the matrix. The lysozyme test showed relevant changes in the degradability rate, because the weight loss of the films at 3 weeks decreased from 53% for starch-chitosan matrix and up to 34% for composites with 5wt% of modified quill. The results corroborated that chicken feather materials can be useful for the development of a manufacturing process for starch composites, and the decomposition of starch-chitosan composites can be controlled depending on the content and type of keratin.Starch (potato), chitosan, and feather keratin are used for processing biodegradable films produced by extrusion. The morphology of the films is examined with a scanning electron microscope and showed the excellent dispersion of keratin. The dispersion is the result of compatibility between the polysaccharides and proteins, as well as the proper operation of the extrusion process. Water solubility of the starch-chitosan films decreased with an increase of keratin materials. The storage modulus increased up to 137% for the composites with unmodified ground quill, and by 192% for composites with modified ground quill. In a tensile test, the composites with unmodified and modified quill reached outstanding increments up to 8160 and 7250% in elastic modulus, respectively, compared to the matrixUniversidad Autonoma del Estado de Mexico Tecnologico Nacional de Mexico Universidad Nacional Autonoma de Mexico Universidad Autonoma de Cd. Juare

Chitosan–Starch–Keratin composites: Improving thermo-mechanical and degradation properties through chemical modification

The lysozyme test shows an improved in the degradability rate, the weight loss of the films at 21 days is reduced from 73 % for chitosan-starch matrix up to 16 % for the composites with 5wt% of quill; but all films show a biodegradable character depending on keratin type and chemical modification. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiat-ing chitosan–starch films with sustainable featuresChitosan–starch polymers are reinforced with different keratin materials obtained from chicken feather. Keratin materials are treated with sodium hydroxide; the modified surfaces are rougher in comparison with untreated surfaces, observed by Scanning Electron Microscopy. The results obtained by Differential Scanning Calorimetry show an increase in the endothermic peak related to water evaporation of the films from 92 °C (matrix) up to 102–114 °C (reinforced composites). Glass transition temperature increases from 126 °C in the polymer matrix up to 170–200 °C for the composites. Additionally, the storage modulus in the composites is enhanced up to 1614 % for the composites with modified ground quill, 2522 % for composites with modified long fiber and 3206 % for the composites with modified short fiber. The lysozyme test shows an improved in the degradability rate, the weight loss of the films at 21 days is reduced from 73 % for chitosan-starch matrix up to 16 % for the composites with 5wt% of quill; but all films show a biodegradable character depending on keratin type and chemical modification. The outstanding properties related to the addition of treated keratin materials show that these natural composites are a remarkable alternative to potentiat-ing chitosan–starch films with sustainable featuresUniversidad Autónoma del Estado de México Tecnológico Nacional de México, Instituto Tecnológico de Querétaro Universidad Nacional Autónoma de México Tecnológico Nacional de México, Instituto Tecnológico de Celaya Universidad Autónoma de Cd. Juáre

Evaluación físico-química de compositos madera-plástico para el diseño de productos

Los residuos de madera son tratados comúnmente como desecho y existe un problema para su disposición. Actualmente, las fibras son utilizadas para producir papel, material de construcción y bioplásticos; aunque han sido desarrollados previamente materiales compuestos madera-plástico, no hay reportes de uno con matriz de policaprolactona. Durante la investigación se desarrollaron materiales compuestos policaprolactona-harina de madera de álamo que fueron caracterizados por medio de microscopía electrónica de barrido, espectroscopía infrarrojo por transformada de Fourier, biodegradación, prueba de captación de agua, propiedades mecánicas de flexión a tres puntos y barrido de temperatura. Las imágenes de microscopía electrónica de barrido mostraron materiales compuestos con uniformidad en la matriz, la espectroscopía evidenció interacción del grupo carbonilo de la policaprolactona y el enlace de estiramiento O-C-O con los grupos OH de la madera. Los materiales compuestos son resistentes a la degradación hidrolítica aún bajo los efectos de los rayos UV. De acuerdo con los resultados, se obtuvo un material apropiado para su uso en diseño de productos, por lo que finalmente fue generada una propuesta de diseño del mismo

Lipid nanoparticles for gene therapy in ocular diseases

Objectives Lipid nanoparticles, as a nucleic acid delivery system, have been used as an alternative to treat ocular diseases, since they can cross the ocular barrier and efficiently transfecting nucleic acids to various cells of the eye. The size influences the transfection of genes, biological distribution, diffusion, and cellular uptake. It is therefore important to establish a relationship between size, formulation, and encapsulation percentage. Evidence acquisition In this review, we used a search strategy to compare studies of nanomedicine systems aimed at eye diseases where the size of the nanoparticles and the efficiency of encapsulation of genetic material are reported based on the criteria of Preferred Reporting Items for Systematic Reviews (PRISMA ScR 2020 guidelines). Results Out of the initial 5932, 169 studies met the inclusion criteria and were included to form the basis of the analysis. Nanoparticles reported are composed mainly of PEG-modified lipids, cholesterol, and cationic lipids, that in combination with messenger or interference RNA, allow the formulation of a nanoparticle with an encapsulation efficiency greater than 95%. The diseases treated mainly focus on conditions related to the retina and cornea. Certain characteristics of nanoparticles increase encapsulation efficiency, such as the size of the nanoparticle and the charge of the outer layer of the nanoparticle. Conclusion It is still unknown what characteristics lipid nanoparticles should have to successfully treat human eye illnesses. The in vitro and in vivo investigations covered in this review, however, present encouraging results. To improve encapsulation effectiveness and disease gene silencing, nanoparticle formulation is essential. The most stable nanoparticles are those made mostly of cationic lipids, PEG lipids, and cholesterol, which also effectively encapsulate RNA. The encapsulation efficiency is not only influenced by size, but also by other factors such as methods of preparation

Synergistic Interactions between Tocol and Phenolic Extracts from Different Tree Nut Species against Human Cancer Cell Lines

Tree nuts are rich in polar (phenolic compounds) and non-polar (tocols) antioxidants, with recognized effects in the prevention of diseases such as cancer. These biomolecules possess antiproliferative activity on cancer cells; however, the combined effect of both types of compounds has been scarcely studied, and this approach could give valuable information on the real anticancer potential of tree nuts. In the present study, the antiproliferative activity of pure tocols and phenolic compounds, tocol- and phenolic-rich extracts (TRE and PRE, respectively) from tree nuts and the extracts combinations, was evaluated in four cancer (HeLa, MCF7, PC3, A549) and one control (ARPE) cell lines. The most sensible cell lines were HeLa and MCF7. TRE and PRE from nuts were chemically characterized; γ and δ tocopherols, total tocols, total tocopherols and total phenolic compounds were negatively correlated with cell viability in MCF7 cells. In HeLa cells, only δ and total tocopherols were negatively correlated with cell viability. TRE and PRE had a low effect in reducing cell viability of the cancer cell lines, the most effective extracts were those of emory oak acorn (EOA), pecan nut (PEC) and walnut (WAL), and these were further studied for their pharmacological interactions, using the combination index and the isobologram methods. Combinations of both extracts showed a synergistic and strongly synergistic behavior in the three nuts (EOA, PEC and WAL), with combination indexes between 0.12 and 0.55. These results highlight the need to understand the interactions among components found in complex natural extracts or food products in order to fully understand their bioactivities

Photocatalytical degradation of methyl orange (MO) using ZnO nanoparticles from alkaline wasted batteries. The effect of the MO, catalyst, and organic loads

The photocatalytic degradation of methyl orange (MO) using ZnO nanoparticles is reported. NPs in the range of 40-60 nm were obtained from wasted alkaline batteries anodes. The effect of the MO concentration and the catalyst load were analyzed finding that NPs exhibited similar photocatalytic activities than those reported for ZnO-NPs obtained from pure sources when similar conditions are used. The effect of the organic loads (COD from 60 to 900 ppm) in the catalyst efficiency was studied detecting that COD:60 ppm does not affect the ZnO photocatalytical properties. However, high COD loads (600-900 ppm) make the degradation efficiency almost null

Bioactividad y biocompatibilidad de compósitos de zirconia estabilizada con Y/ hidroxiapatita-Cu, Fosfato Tricálcico-Ag o Fosfato Tricálcico-Ga

The biological compatibility of bone and dental implants is limited, since it is placed until a long time after it has been implanted, due to its low resistance of infections attributed to a quick degradation of the implant which is present in the physiological fluids. Therefore, in this investigation, hydroxyapatite-zirconia (HA-ZrO2) composite materials were developed, where zirconia was stabilized with yttrium and hydroxyapatite was doped with silver, copper and gallium, in order to give biological properties to the composite that the zirconia does not present. Each component of the composite material has different characteristics; such as hydroxyapatite (HA) that provides it a bioactive behavior, On the other hand ZrO2 stabilized with yttrium gives it excellent resistance; otherwise, Ag, Ga and Cu provide antimicrobial properties. To obtain these systems, the materials were synthesized by the Pechini method and chemical precipitation. Afterward the compounds were obtained and tested by bioactivity tests, hemolysis, cell viability studies by the MTT method and osteoblast adhesion by staining, hence there were obtained bioactive, non-hemolytic, non-toxic materials with cell adhesion to the composite. and as a result of that, these awesome materials can be useful for dental implants

Synergistic interactions between tocol and phenolic extracts from tree nuts species against human cancer cell lines

Tree nuts are rich in polar (phenolic compounds) and non-polar (tocols) antioxidants, with recognized effects in the prevention of diseases such as cancer. These biomolecules possess antiproliferative activity on cancer cells; however, the combined effect of both types of compounds has been scarcely studied, and this approach could give valuable information on the real anticancer potential of tree nuts. In the present study, the antiproliferative activity of pure tocols and phenolic compounds, tocol- and phenolic-rich extracts (TRE and PRE, respectively) from tree nuts and the extracts combinations, was evaluated in four cancer (HeLa, MCF7, PC3, A549) and one control (ARPE) cell lines. The most sensible cell lines were HeLa and MCF7. TRE and PRE from nuts were chemically characterized; γ and δ tocopherols, total tocols, total tocopherols and total phenolic compounds were negatively correlated with cell viability in MCF7 cells. In HeLa cells, only δ and total tocopherols were negatively correlated with cell viability. TRE and PRE had a low effect in reducing cell viability of the cancer cell lines, the most effective extracts were those of emory oak acorn (EOA), pecan nut (PEC) and walnut (WAL), and these were further studied for their pharmacological interactions, using the combination index and the isobologram methods. Combinations of both extracts showed a synergistic and strongly synergistic behavior in the three nuts (EOA, PEC and WAL), with combination indexes between 0.12 and 0.55. These results highlight the need to understand the interactions among components found in complex natural extracts or food products in order to fully understand their bioactivitie

Composite scaffolds of chitosan/polycaprolactone functionalized with protein of Mytilus californiensis for bone tissue regeneration

Nowadays, the treatment for bone damage remains a significant challenge. As a result, the development of bioactive three-dimensional scaffolds for bone regeneration has become a key area of study within tissue engineering. This research is focused on the evaluation of the properties of Chitosan (Ch)/Polycaprolactone (PCL) scaffolds with the Mytilus californiensis protein by Thermally Induced Phase Separation (TIPS). This study used the extrapalleal fluid protein from Mytilus californiensis because it increases biological processes that support bone regeneration. Two methodologies were used for the scaffolds functionalization: (I) an immersion process in a solution with the protein and (II) the protein direct addition during the scaffold synthesis. The scaffolds were analyzed by Fourier Transformed Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), and Mechanical Compression test to determine the composition, morphology, and mechanical properties of each material. In vitro analysis of biodegradation, bioactivity, and biocompatibility were also performed. The scaffolds with the protein added directly presented superior properties in the tests of bioactivity and cellular proliferation, making these composites attractive for the area of bone regeneration