Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.262
Filtrar
Más filtros

Medicinas Complementárias
Intervalo de año de publicación
1.
Int J Biol Macromol ; 267(Pt 1): 131539, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38608994

RESUMEN

Sustainable strategies to improve the water resistance of cellulose paper are actively sought. In this work, polymeric microspheres (PMs), prepared through emulsion polymerization of cellulose nanofibers stabilized rubber seed oil-derived monomer, were investigated as coatings on corrugated medium paper (CMP). After infiltrating porous paper with PMs, the water-resistant corrugated papers (WRCPn) with enhanced mechanical properties were obtained. When 30 wt% PMs were introduced, WRCP30 turned out to be highly compacted with an increased water contact angle of 106.3° and a low water vapor transmission rate of 81 g/(m2 d) at 23 °C. Meanwhile, the tensile strength of WRCP30 increased to 22.2 MPa, a 4-fold increase from CMP. When tested in a well-hydrated state, 71% of its mechanical strength in the dry state was maintained. Even with a low content of 10 wt% PMs, WRCP10 also exhibited stable tensile strength and water wettability during the cyclic soaking-drying process. Thus, the plant oil based sustainable emulsion polymers provide a convenient route for enhancing the overall performance of cellulose paper.


Asunto(s)
Celulosa , Microesferas , Aceites de Plantas , Resistencia a la Tracción , Agua , Celulosa/química , Agua/química , Aceites de Plantas/química , Papel , Humectabilidad , Polímeros/química , Emulsiones/química , Porosidad , Nanofibras/química
2.
Arch Oral Biol ; 162: 105942, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38452415

RESUMEN

OBJECTIVES: The aim of this scoping review was to evaluate the available scientific evidence regarding the use of flavonoids in the treatment of caries-affected dentin focusing on bonding to dentin. METHODS: A comprehensive literature search was performed in five databases from March 2022 and updated in April 2023: PubMed, EMBASE, Scopus, Web of Science, and Scielo. Additionally, the references of included studies were manually searched. Gray literature was excluded from the review. STUDY SELECTION: Inclusion criteria included in vitro, in situ, and in vivo studies (animal or human) published in English. Abstracts, reviews, case reports, book chapters, doctoral dissertations, guidelines, and studies using pure plant extracts were excluded. Data collected from the selected studies were summarized and subjected to narrative and descriptive analysis. Out of the 91 studies identified, only 16 studies met the inclusion criteria. RESULTS: The review analyzed eight different flavonoids (hesperidin, galardin, proanthocyanidin, genipin, quercetin, naringin, epigallocatechin-3-gallate, and other catechins subtypes) used as pretreatment or loaded into adhesive systems, primers, and phosphoric acid. The use of flavonoids improved the mechanical properties of the materials and modified the biological properties of the dentin, reducing collagen loss by the inhibition of proteolytic activity of matrix metalloproteinases (MMPs). CONCLUSIONS: Based on the findings of this scoping review, it can be concluded that the use of flavonoids as pretreatment or incorporation into dental materials preserves collagen in the hybrid layer, inhibiting the MMPs activities, modifying the collagen fibrils of the dentin matrix and improving the mechanical properties of the dental adhesive systems. Therefore, it represents a promising approach for promoting dentin biomodification. This can result in more stable bonding of adhesive restorations to caries-affected dentin.


Asunto(s)
Recubrimiento Dental Adhesivo , Caries Dental , Humanos , Flavonoides/farmacología , Susceptibilidad a Caries Dentarias , Colágeno , Caries Dental/tratamiento farmacológico , Metaloproteinasas de la Matriz , Dentina , Recubrimientos Dentinarios , Ensayo de Materiales , Cementos de Resina , Resistencia a la Tracción
3.
Mar Biotechnol (NY) ; 26(2): 276-287, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38441733

RESUMEN

The present study aims to characterize and to evaluate the biological effects of a skin dressing manufactured with the organic part of the Chondrilla caribensis marine sponge (called spongin-like collagen (SC)) associated or not to photobiomodulation (PBM) on the skin wound healing of rats. Skin dressings were manufactured with SC and it was characterized using scanning electron microscopy (SEM) and a tensile assay. In order to evaluate its biological effects, an experimental model of cutaneous wounds was surgically performed. Eighteen rats were randomly distributed into three experimental groups: control group (CG): animals with skin wounds but without any treatment; marine collagen dressing group (DG): animals with skin wounds treated with marine collagen dressing; and the marine collagen dressing + PBM group (DPG): animals with skin wounds treated with marine collagen dressing and PBM. Histopathological, histomorphometric, and immunohistochemical evaluations (qualitative and semiquantitative) of COX2, TGFß, FGF, and VEGF were done. SEM demonstrates that the marine collagen dressing presented pores and interconnected fibers and adequate mechanical strength. Furthermore, in the microscopic analysis, an incomplete reepithelialization and the presence of granulation tissue with inflammatory infiltrate were observed in all experimental groups. In addition, foreign body was identified in the DG and DPG. COX2, TGFß, FGF, and VEGF immunostaining was observed predominantly in the wound area of all experimental groups, with a statistically significant difference for FGF immunostaining score of DPG in relation to CG. The marine collagen dressing presented adequate physical characteristics and its association with PBM presented favorable biological effects to the skin repair process.


Asunto(s)
Vendajes , Colágeno , Poríferos , Piel , Cicatrización de Heridas , Animales , Cicatrización de Heridas/efectos de la radiación , Ratas , Colágeno/metabolismo , Piel/efectos de la radiación , Terapia por Luz de Baja Intensidad , Masculino , Factor A de Crecimiento Endotelial Vascular/metabolismo , Ciclooxigenasa 2/metabolismo , Modelos Animales de Enfermedad , Ratas Wistar , Factor de Crecimiento Transformador beta/metabolismo , Resistencia a la Tracción , Factores de Crecimiento de Fibroblastos/metabolismo , Microscopía Electrónica de Rastreo
4.
J Mater Chem B ; 12(13): 3262-3272, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38456357

RESUMEN

Traditional petroleum-based plastics have high energy consumption, require professional equipment, are non-degradable after use, and lack antibacterial properties, making it impossible to achieve long-lasting freshness in fruits and vegetables. Herein, we report a novel co-type film-forming method with low energy consumption and without production equipment, which uses PVA-borax gel as a substrate and adds a certain proportion of CMC and TA to prepare multifunctional CMC/TA@PVA-borax composite hydrogels (CTPB). The dynamic borax ester bonding and hydrogen bonding in the CTPB hydrogel results in an ultra-high tensile strength of more than 5500% and rapid self-healing within 8 s. Interestingly, hydrogels can be arbitrarily shaped and stretched like play dough and thus can be stretched into ductile films by co-type film formation. The antimicrobial properties of the hydrogel film can be attributed to the synergistic effects of TA and borax. The mussel structure of TA allows the hydrogel film to adhere directly to different surfaces for more effective bacterial killing. In addition, the hydrogel film has a high level of biosafety and biodegradability and shows good performance in fruit storage. This study provides a convenient and low-energy method for the preparation of films, which in part reduces the increasing environmental pollution caused by petroleum-based plastics.


Asunto(s)
Boratos , Frutas , Petróleo , Resistencia a la Tracción , Alcohol Polivinílico/química , Hidrogeles/química , Plásticos
5.
Int J Biol Macromol ; 263(Pt 1): 130165, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38367784

RESUMEN

This work reports on the extraction and characterization of the behavior of starch from residues of several potato varieties (Criolla, Sabanera and Pastusa) of Colombian origin from the Andean region using different techniques and the evaluation of the effect of citric acid (CA) on the grain morphology. Additionally, films were produced with each one of the extracted starches and glycerol. Pastusa variety starch shows a higher granule size than the other varieties and Pastusa starch shows lower amylose content compared to Sabanera and Criolla. Criolla and Pastusa starches exhibit more thermal stability than Sabanera starch. Starch-glycerol films were also produced using the cast solving method. The films were mechanically analyzed by tensile test and the barrier properties were assessed by water vapor permeability (WVP). The tensile strength of the films varied in the 2.0-2.4 MPa range, while the elongation at break was comprised between 25 and 32 %. With regard to water vapor permeability, the obtained values fall within the 4-7 × 10-10 g m-1 s-1 Pa-1 range. It was observed that the thickness of the films and the protein content affected water vapor permeability, increasing this value at higher levels of thickness.


Asunto(s)
Películas Comestibles , Solanum tuberosum , Almidón/química , Solanum tuberosum/química , Vapor , Glicerol/química , Colombia , Permeabilidad , Resistencia a la Tracción
6.
Int J Biol Macromol ; 263(Pt 2): 130467, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38423433

RESUMEN

In order to solve the problem of uneven microporous structure of Poly(L-lactic acid) (PLLA) bulk orientation by using biological safety multi-functional plant oil as chain extenders (CE), multi-armed flexible chains were introduced into PLLA through reactive processing to prepare long chain branched PLLA (LCB-PLLA). When the total content of the CE was 6.15 wt%, PLLA and the CE reacted most fully, while maintaining the tensile strength of PLLA and improving toughness. After introducing the LCB structure, the presence of multi-armed flexible chains increased the mobility of the molecular chains, resulting in a significantly lower degree of crystallinity. When the draw ratio up to 900 %, the crystallinity of LCB-PLLA-F-900 % was only 45.15 %, lower than that of PLLA-F-900 %. Thanks to the mobility of polymer chains can be enhanced, which reduces the degree of crystallinity while promoting the uniform growth of oriented microporous structures. Finally, an oriented micro-porous biomimetic LCB-PLLA material with an average cell diameter of 540 nm was prepared, and the results of in vitro cell culture showed that the oriented micro-porous LCB-PLLA biomimetic material was more conducive to cell proliferation.


Asunto(s)
Biónica , Poliésteres , Poliésteres/química , Polímeros/química , Resistencia a la Tracción , Porosidad , Ácido Láctico/química
7.
Clin Oral Investig ; 28(1): 106, 2024 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-38244108

RESUMEN

OBJECTIVES: To evaluate the effect of bromelain associated with Biosilicate on the bond strength (BS) of a universal adhesive system to sound (SD) and caries-affected dentin (CAD), and on the proteolytic activity. MATERIALS AND METHODS: Cavities were prepared in 360 molars, half submitted to cariogenic challenge. Teeth were separated into groups (n=20): Control-No treatment; CHX-0.12% chlorhexidine; NaOCl-5% sodium hypochlorite; Br5%-5% bromelain; Br10%-10% bromelain; Bio-10% Biosilicate; NaOClBio-NaOCl+Bio; Br5%Bio-Br5%+Bio; Br10%Bio-Br10%+Bio. Following treatments, the adhesive system was applied, and cavities were restored. Samples were sectioned into sticks and stored at 37 °C for 24 h, 6 months, and 1 year. Microtensile BS (2-way ANOVA, Bonferroni's test, α=0.05), fracture patterns (SEM), and adhesive interfaces (TEM) were evaluated. Bacterial collagenase assay and in situ zymography were performed. RESULTS: In CAD, Br10% presented higher BS (p=0.0208) than Br5%Bio. Br5% presented higher BS (p=0.0033) after 6 months than after 24 h; and association of treatments, higher BS (p<0.05) after aging than after 24 h. Mixed fractures were the most prevalent. Association of treatments promoted a more uniform hybrid layer with embedded Bio particles. Experimental groups presented lower (p<0.0001) relative fluorescence units than Control. Bromelain, associated or not with Bio, showed collagenolytic degradation. CONCLUSIONS: Bromelain associated with Biosilicate did not affect the BS to SD. In CAD, Br5%Bio decreased immediate BS but had no long-term influence. This association decreased the proteolytic activity. CLINICAL RELEVANCE: Bromelain and Biosilicate may enhance the longevity of adhesive restorations by inhibiting endogenous proteases.


Asunto(s)
Recubrimiento Dental Adhesivo , Caries Dental , Humanos , Cementos Dentales/química , Recubrimientos Dentinarios/química , Bromelaínas/farmacología , Bromelaínas/análisis , Ensayo de Materiales , Dentina , Cerámica , Resistencia a la Tracción , Cementos de Resina/farmacología
8.
Int J Biol Macromol ; 254(Pt 2): 127927, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37944730

RESUMEN

Starch film has poor tensile properties and poor water resistance. We aimed to improve these properties by adding kaolin impregnated with calico plant extract (CP-Kaolin). UV-Vis spectrophotometry showed that the calico plant extract (CPE) contained 4867.52 mg/L of total phenolic compounds and betacyanins were the predominant constituents. CP-Kaolin was characterized by Fourier transform infrared spectroscopy (FTIR), zeta potential, scanning electron microscopy (SEM) and x-ray diffraction (XRD) analysis. FTIR analysis showed that betacyanins were adsorbed on kaolin via hydrogen bonding. Zeta potential analysis confirmed the adsorption of betacyanins on kaolin. The intercalation of betacyanins between kaolin platelets was observed by XRD. SEM revealed that CP-Kaolin was well dispersed and embedded within the starch matrix. It was found that the addition of 10 wt% of CP-Kaolin increased the water resistance, tensile strength and thermal stability of starch film. Moreover, starch film containing 10 wt% of CP-Kaolin was sensitive to the change in pH of the fish during storage. Therefore, the addition of CP-Kaolin improved the properties of starch film and starch film composite with CP-Kaolin could be applied as a smart packaging in the food industry.


Asunto(s)
Extractos Vegetales , Almidón , Animales , Almidón/química , Extractos Vegetales/farmacología , Extractos Vegetales/química , Caolín , Betacianinas , Resistencia a la Tracción , Espectroscopía Infrarroja por Transformada de Fourier , Agua , Embalaje de Alimentos
9.
Int J Prosthodont ; 37(1): 41-48, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-37222545

RESUMEN

PURPOSE: To evaluate the effect of adding tea tree oil to denture liners on Candida albicans and bond strength to the acrylic denture base. MATERIALS AND METHODS: Disc-shaped specimens were fabricated from silicone-based resilient liner (Tokuyama, Molloplast), acrylic-based hard liner (GC Reline), and acrylic-based soft liner (Visco-gel). Tea tree oil (TTO) was incorporated into the liners at varying concentrations (0% [control], 2%, 5%, 8%). C albicans were counted by viable colony count, and optical density (OD) was measured with a spectrophotometer. The tensile strength to heat polymerized acrylic denture base was measured in a universal testing machine. The compliance of the data to the distribution of normality was evaluated using the Shapiro Wilk test. Two-way ANOVA, Bonferroni correction, and paired sample t test were performed (α = .05). RESULTS: The addition of TTO into liners provided a significant decrease in the OD values (P < .001). The control groups of the liners presented the highest colony counts, whereas increasing TTO decreased the results (P < .01). According to tensile bond strength test, 8% TTO addition resulted in a significant decrease for Tokuyama (P < .01) and Molloplast liners (P < .05), while 2% TTO resulted in significance for GC Reline (P < .001). CONCLUSIONS: Denture liners containing increasing percentages of TTO presented lower amounts of C albicans colonies and decreased bond strength to the denture bases. When using TTO for its antifungal properties, the amount added should be carefully selected because the tensile bond strength may be affected.


Asunto(s)
Recubrimiento Dental Adhesivo , Alineadores Dentales , Aceite de Árbol de Té , Elastómeros de Silicona/química , Bases para Dentadura , Candida albicans , Aceite de Árbol de Té/farmacología , Resinas Acrílicas/química , Ensayo de Materiales , Polimetil Metacrilato , Resistencia a la Tracción
10.
Int J Biol Macromol ; 254(Pt 2): 127791, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37923044

RESUMEN

The current study focuses on the preparation and characterization of potato starch-based biocomposite films by reinforcing them with banana fiber. The banana fibers were modified using ultrasonication and cellulase enzyme, individually and in combination. Both native and modified banana fibers underwent physical, morphological, FTIR, and crystallinity analyses. The resulting biocomposite films, created by incorporating native and treated banana fibers, were then evaluated for their mechanical, thermal, barrier, and biodegradable properties. The findings indicated that combining ultrasound with enzyme treatment of banana fibers in the potato starch matrix led to a substantial reduction in water-sorption and water-vapor permeability (0.156 g mm m-2 h-1 kPa-1) of the packaging films. Additionally, the mechanical properties (5.02 MPa-Tensile strength, 4.27 MPa-Sealability) of the films significantly improved with the inclusion of modified banana fibers. FTIR analysis revealed similar spectra for all modified samples, along with enhanced crystallinity. Moreover, the thermal stability of the developed films was enhanced by the incorporation of modified banana fibers. Scanning electron microscopy showed that the modified fibers exhibited smooth surfaces and an even distribution of spaces compared with the native fibers. The biocomposite films demonstrated biodegradation within 42 days. Furthermore, the packaging application was tested with grapes, which showed that the films could maintain storability for up to 8 days. Overall, these results suggest a promising eco-friendly method for producing packaging films with biocompatible, biodegradable, and non-toxic properties.


Asunto(s)
Musa , Solanum tuberosum , Vitis , Celulosa , Agua , Resistencia a la Tracción , Embalaje de Alimentos/métodos , Almidón , Permeabilidad
11.
Int J Biol Macromol ; 256(Pt 2): 128511, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38043658

RESUMEN

Water resistance, mechanical behavior and coloration of pectin needs to be tuned for packing utilization. Plasma was used for the treatment of natural products, but there is no research on its effect on the biomass in the presence of ammonia. Though the reaction of pectin (PE) and ammonia was known to impart the ammonolysis and de-esterification, the plasma treatment on PE solution containing ammonia was explored to exemplify the amination and polymerization of the carbohydrate at the ambient condition. The plasma treatment increased the coloration of the solution due to the deprotonation of PE for the production of more sp2 carbon. The film from the amination of PE showed higher hydrophobicity and water stability than the bare PE. The plasma treatment alone decreased the Young's modulus (4.3 MPa versus 22 MPa), while the nitrogen addition enhanced the Young's modulus to 160 MPa and increased the tensile strength (28.7 MPa versus 25.8 MPa of PE). The hydrogen bonds from the amine group induced a glass-to-rubber transition at 77.9 °C by the increasing the crosslinking. This work provided a facile way of aminating and conjugating the biomass in solution to produce polymer with improved mechanical properties using plasma and ammonia incorporation.


Asunto(s)
Pectinas , Polímeros , Polímeros/química , Pectinas/química , Amoníaco , Agua , Resistencia a la Tracción
12.
J Esthet Restor Dent ; 36(5): 770-777, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38014602

RESUMEN

OBJECTIVE: This study evaluated the effect of bromelain and propolis extract on the bond strength (BS) of a universal adhesive system to eroded dentin. MATERIALS AND METHODS: Sixty human molars with exposed dentin were halved, with one half protected by composite resin and the other subjected to erosive treatment followed by remineralization. After the erosive treatment, the composite resin was removed, and the teeth were randomly assigned to three groups (n = 20): Adhesive-Control System; Br-10%; Pr-16%. Following the treatments, composite resin blocks were built on the dentin surfaces and sticks of 0.9 mm2 were obtained and stored in distilled water at 37°C for 24 h and 6 months. After these periods, the sticks underwent bond strength testing and the data were analyzed using 2-way ANOVA, Bonferroni test, p < 0.05. Fracture patterns were observed using light microscope and scanning electron microscopy. RESULTS: Irrespective of the substrate and aging duration, propolis demonstrated higher BS (p < 0.05) compared to the other treatments. Eroded dentin exhibited greater removal of the smear layer and dentinal tubules with a larger diameter than sound dentin, especially when treated with bromelain, resulting in the formation of resin tags. CONCLUSIONS: Propolis consistently promoted the highest bond strength, irrespective of aging or substrate. Eroded dentin treated with propolis, or bromelain exhibited a higher prevalence of non-adhesive fractures and resin tag formation. CLINICAL SIGNIFICANCE: Propolis shows promise for enhancing the longevity of adhesive restorations in eroded dentin due to its ability to promote high bond strength.


Asunto(s)
Recubrimiento Dental Adhesivo , Própolis , Humanos , Bromelaínas , Recubrimientos Dentinarios/química , Cementos de Resina/química , Própolis/farmacología , Dentina , Resinas Compuestas/química , Resistencia a la Tracción , Ensayo de Materiales
13.
Colloids Surf B Biointerfaces ; 234: 113712, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38157762

RESUMEN

In the present study, a film based on the gelatin skin of tilapia (Oreochromis niloticus) was developed, using surfactants and adding plant extract of pitomba seed (Talisia esculenta). The aim was to investigate the mechanical and barrier properties of the cover, as well as its effectiveness in conserving papayas against diseases caused by fungi. The film presented tensile strength of 38.78 MPa, elongation of 120.49%, and water vapor permeability of 5.90 g.mm.h-1.m2.kPa-1 when equally composed of SDS and Tween 80, in a percentage of 40% in relation to the total mass of the film. The films lasted 12 d in an environment with a relative humidity of 75% (25 ºC), longer than the shelf life of papaya (limited to 8 d). With applying the film with the extract, the incidence of diseases such as anthracnose, fusariosis, and stem rot caused by these microorganisms in papaya was reduced.


Asunto(s)
Carica , Cíclidos , Sapindaceae , Tilapia , Animales , Gelatina , Extractos Vegetales , Hawaii , Resistencia a la Tracción , Permeabilidad , Embalaje de Alimentos
14.
Int J Biol Macromol ; 258(Pt 1): 128740, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38101678

RESUMEN

Acetylated starch shows enhanced thermal stability and moisture resistance, but its compatibilization with other more hydrophilic polysaccharides remains poor or unknown. In this study, the feasibility of thermomechanically compounding organocatalytically acetylated pea starch (APS), produced at two different degrees of substitution with alkanoyl groups (DSacyl, 0.39 and 1.00), with native pea starch (NPS), high (HMP) and low methoxyl (LMP) citrus pectin, and sugar beet pectin (SBP, a naturally acetylated pectin) for developing hot-pressed bioplastics was studied. Generally, APS decreased hydrogen bonding (ATR-FTIR) and crystallinity (XRD) of NPS films at different levels, depending on its DSacyl. The poor compatibility between APS and NPS or HMP was confirmed by ATR-FTIR imaging. Contrariwise, APS with DSacyl 1 was effectively thermomechanically mixed with the acetylated SBP matrix, maintaining homogeneous distribution within it (ATR-FTIR imaging). APS (any DSacyl) significantly increased the visible/UV light opacity of NPS-based films and decreased their water vapor transmission rate (WVTR, by ca. 11 %) and surface water wettability (by ca. 3 times). In comparison to NPS-APS films, pectin-APS showed higher visible/UV light absorption, tensile strength (ca.2.9-4.4 vs ca.2.4 MPa), and Young's modulus (ca.96-116 vs ca.60-70 MPa), with SBP-APS presenting significantly lower water wettability than the rest of the films.


Asunto(s)
Pisum sativum , Almidón , Resistencia a la Tracción , Pectinas
15.
Int J Biol Macromol ; 253(Pt 4): 126959, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37739289

RESUMEN

The increasing number of petroleum-based plastics has caused severe environmental pollution, which has attracted great research interest in the development of low-cost, renewable, and degradable starch-based bioplastics. However, developing starch-based bioplastics with robust mechanical strength, excellent water resistance, and thermal resistance remains a great challenge. In this study, we presented a simple and efficient method for preparing high-performance novel starch-based bioplastics with chemical and physical double crosslinking network structures filled with 2,2,6,6-tetramethylpiperidine 1-oxy-oxidized cellulose nanofibers and zinc oxide nanoparticles. Compared with pure starch-based bioplastics, the tensile strength of the novel robust strength starch-based bioplastics increased by 431.2 %. The novel starch-based bioplastics exhibited excellent mechanical properties (tensile strength up to 24.54 MPa), water resistance, thermal resistance, and biodegradability. In addition, the novel starch-based bioplastics could be reused, crushed, dissolved, and re-poured after use. After recycling, the novel starch-based bioplastics could be discarded in the soil to achieve complete degradation within six weeks. Owing to these characteristics, the novel starch-based bioplastics are good alternatives used to replace traditional petroleum-based plastics and have great development prospects.


Asunto(s)
Petróleo , Almidón , Almidón/química , Plásticos/química , Agua , Resistencia a la Tracción
16.
Lasers Med Sci ; 38(1): 224, 2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37773548

RESUMEN

This study aimed to assess the efficacy of phototherapy with an Er, Cr:YSGG laser on the bond strength of dentin using two different adhesive systems after chlorhexidine (CHX) application. Twenty-four non-carious human molar teeth were separated into three main groups: negative control Group A (Group A), CHX and phototherapy with an Er, Cr:YSGG laser (Group PC), and CHX with conventional diamond bur (no phototherapy) (Group C). These groups were divided into two subgroups based on adhesives: Clearfil Universal Quick Bond and Clearfil SE Bond. To evaluate the microtensile bond strength, the occlusal enamel surfaces of the teeth were removed with a low-speed, water-cooled diamond bur to expose hard dentin tissue. The teeth within Group PC were treated with Er, Cr:YSGG phototherapy. The surfaces were then disinfected with 0.2% chlorhexidine gluconate. Subgroups were applied according to the manufacturer's instructions using the adhesive systems mentioned above. Following adhesive application, the teeth were restored with composite resin. A microtensile bond strength test was performed on the test sticks obtained from the teeth using a universal test device. Data were analyzed using variance analysis (ANOVA) at a significance level of p < 0.05. Among all groups, the highest bond strength was achieved with Clearfil SE Bond with CHX + phototherapy (45.6 ± 4.2), while the lowest was achieved with Clearfil Universal Quick Bond without phototherapy (control group) (27.0 ± 6.7) (p < 0.05). Phototherapy with Er, Cr: YSGG following chlorhexidine application enhanced the bond strength of both the bond systems (p < 0.05).


Asunto(s)
Recubrimiento Dental Adhesivo , Láseres de Estado Sólido , Humanos , Adhesivos , Clorhexidina/farmacología , Dentina , Láseres de Estado Sólido/uso terapéutico , Fototerapia , Resistencia a la Tracción , Diamante , Recubrimientos Dentinarios/química , Ensayo de Materiales
17.
Int J Mol Sci ; 24(14)2023 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-37511327

RESUMEN

The dental prophylactic cleaning of a damaged resin-based composite (RBC) restoration with sodium bicarbonate can change the surface characteristics and influence the repair bond strength. The purpose of this study was to compare the effect of sodium bicarbonate (SB) and aluminum oxide (AO) surface treatments on the microtensile bond strength (µTBS) of repaired, aged RBC. Bar specimens were prepared from microhybrid RBC and aged in deionized water for 8 weeks. Different surface treatments (AO air-abrasion; SB air-polishing), as well as cleaning (phosphoric acid, PA; ethylene-diamine-tetraacetic-acid, EDTA) and adhesive applications (single bottle etch-and-rinse, ER; universal adhesive, UA), were used prior to the application of the repair RBC. Not aged and aged but not surface treated RBCs were used as positive and negative controls, respectively. The repaired blocks were cut into sticks using a precision grinding machine. The specimens were tested for tensile fracture and the µTBS values were calculated. Surface characteristics were assessed using scanning electron microscopy. AO-PA-UA (62.6 MPa) showed a 20% increase in µTBS compared to the NC (50.2 MPa), which proved to be the most significant. This was followed by SB-EDTA-UA (58.9 MPa) with an increase of 15%. In addition to AO-PA-UA, SB-EDTA-UA could also be a viable alternative in the RBC repair protocol.


Asunto(s)
Resinas Compuestas , Recubrimiento Dental Adhesivo , Resinas Compuestas/química , Óxido de Aluminio/química , Bicarbonato de Sodio , Ácido Edético , Propiedades de Superficie , Microscopía Electrónica de Rastreo , Materiales Dentales , Resistencia a la Tracción , Ensayo de Materiales , Cementos de Resina/química
18.
Molecules ; 28(11)2023 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-37298757

RESUMEN

This study aimed to improve the physical, mechanical, and biological properties of a monolayer pectin (P) film containing nanoemulsified trans-Cinnamaldehyde (TC) by incorporating it between inner and outer layers of ethylcellulose (EC). The nanoemulsion had an average size of 103.93 nm and a zeta potential of -46 mV. The addition of the nanoemulsion increased the opacity of the film, reduced its moisture absorption capacity, and improved its antimicrobial activity. However, the tensile strength and elongation at break of the pectin films decreased after the incorporation of nanoemulsions. Multilayer films (EC/P/EC) showed a higher resistance to breaking and better extensibility compared to monolayer films. The antimicrobial activity of both mono and multilayer films was effective in inhibiting the growth of foodborne bacteria during storage of ground beef patties at 8 °C for 10 days. This study suggests that biodegradable antimicrobial multilayer packaging films can be effectively designed and applied in the food packaging industry.


Asunto(s)
Antiinfecciosos , Animales , Bovinos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Fenómenos Químicos , Resistencia a la Tracción , Embalaje de Alimentos , Pectinas
19.
Int J Biol Macromol ; 242(Pt 4): 125099, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37263328

RESUMEN

Natural fibers are available as an essential substitute for synthetic fiber in many applications. However, the sensitivity of Chinese Windmill Palm or Trachycarpus Fortune Fiber (TFF) to water causes low interfacial bonding between the matrix and the fiber and at the end reduces the mechanical properties of the composite product. Alkaline treatment improves mechanical properties and does not affect water absorption. Hence, additional treatment in the coating is required. This study uses alkaline treatment and coating modification using blended chitosan and Acrylated Epoxidized Soybean Oil (AESO). Blend coating between AESO and chitosan is performed to increase water absorption and mechanical properties. TFF water resistance improved significantly after the coating, with water absorption of the alkaline/blend coating-TFF of 3.98 % ± 0.52 and swell ability of 3.156 % ± 0.17. This indicated that blend coating had formed a cross-link of fiber and matrix after alkalization. Thus, the single fiber tensile strength increased due to the alkaline treatment, and water absorption decreased due to the coating. The combination of alkaline treatment and blend coating on TFF brings excellent properties, as shown by the increase in tensile strength in both single fiber test and composite.


Asunto(s)
Arecaceae , Biopolímeros , Quitosano , Materiales Biocompatibles Revestidos , Aceite de Soja , Arecaceae/química , Quitosano/química , Álcalis/química , Resistencia a la Tracción , Aceite de Soja/química , Interacciones Hidrofóbicas e Hidrofílicas , Biopolímeros/química , Materiales Biocompatibles Revestidos/química
20.
Macromol Biosci ; 23(9): e2300039, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37203244

RESUMEN

Meshes from natural silk are hand knitted and surface functionalized to facilitate hernia repair and other load bearing, tissue applications. Purified organic silk is - hand knitted and then coated with chitosan (CH)/bacterial cellulose (BC) blend polymer using four phytochemicals such as pomegranate (PG) peel, Nigella sativa (NS) seed, Licorice root (LE), and Bearberry leaf extracts (BE) separately. Characterizations using GCMS analysis shows the presence of bioactive chemicals in the extracts. Scanning electron microcopy (SEM) shows that the surface is coated with the composite polymer t. Fourier transform infrared spectroscopy (FTIR) shows significant elements found in CH, BC, and phytochemicals in plant extracts with no chemical changes. Tensile strength of the coated meshes is higher to support tissue as implants. The release kinetics suggest sustained release of phytochemical extracts. In vitro studies confirmed the noncytotoxic, biocompatible, wound healing potential of the meshes. Furthermore, gene expression analysis of 3-wound healing genes shows marked increase in the in vitro cell cultures due to the presence of extracts. These results suggest that the composite meshes can efficiently support hernia closure while facilitating wound/tissue healing and combating bacterial infections. Therefore, these meshes can be good candidates for fistula and cleft palate repair.


Asunto(s)
Quitosano , Quitosano/farmacología , Quitosano/química , Seda , Cicatrización de Heridas , Polímeros , Resistencia a la Tracción , Celulosa/química , Mallas Quirúrgicas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA