RESUMO
Alginate is one of the most important marine colloidal polysaccharides, and its oligosaccharides have been proven to possess diverse biological functions. Alginate lyases could specifically degrade alginate and therefore serve as desirable tools for the research and development of alginate. In this report, a novel catalytic domain, which demonstrated no significant sequence similarity with all previously defined functional domains, was verified to exhibit a random endo-acting lyase activity to alginate. The action pattern analysis revealed that the heterologously expressed protein, named Aly44A, preferred to degrade polyM. Its minimum substrates and the minimum products were identified as unsaturated alginate trisaccharides and disaccharides, respectively. Based on the sequence novelty of Aly44A and its homologs, a new polysaccharide lyase family (PL44) was proposed. The discovery of the novel enzyme and polysaccharide lyase family provided a new entrance for the gene-mining and acquiring of alginate lyases, and would facilitate to the utilization of alginate and its oligosaccharides.
Assuntos
Alginatos , Polissacarídeo-Liases , Polissacarídeo-Liases/metabolismo , Polissacarídeo-Liases/química , Polissacarídeo-Liases/genética , Alginatos/química , Alginatos/metabolismo , Especificidade por Substrato , Domínio Catalítico , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Sequência de Aminoácidos , Ácidos Hexurônicos/química , Ácidos Hexurônicos/metabolismoRESUMO
Biopolymers application in biomedical areas has been limited due to the physicochemical degradation that occurs using conventional processing/sterilization methods (e.g., steam heat, γ-radiation, ethylene oxide). Aiming to avoid/minimize degradation and preserve their properties, supercritical carbon dioxide (scCO2) has been proposed as an alternative sterilization method for such materials. ScCO2 can simultaneously be used as a drying method to produce aerogels (i) and sterilize them (ii). However, a solvent exchange is required to prepare the alcogel from hydrogel, achievable through high-pressure solvent exchange (HPSE) (iii). This study integrated three processes: HPSE, scCO2 drying, and sterilization to prepare alginate-gelatine sterilized aerogels. Two scCO2 sterilization methods were tested. Results showed that sterilization did not compromise the aerogels' chemical, thermal and swelling properties. Conversely, Young's Modulus increased, and BET surface area decreased, due to the structural changes caused by the fast pressurization/depressurization rates applied during sterilization. Regarding the sterilization efficiency, results showed a reduction in contamination throughout the process, achieving a SAL of 10-4. The sterilized aerogels were non-cytotoxic in vitro and showed improved wound-healing properties. The innovative integrated process produced decontaminated/sterile and ready-to-use aerogels reducing process time by 75 %, from 2 days up to 12 h without compromising the aerogel's properties.
Assuntos
Alginatos , Dióxido de Carbono , Gelatina , Géis , Esterilização , Alginatos/química , Gelatina/química , Esterilização/métodos , Dióxido de Carbono/química , Géis/química , Animais , Cicatrização/efeitos dos fármacos , Hidrogéis/química , Ácido Glucurônico/química , Solventes/química , Camundongos , Ácidos Hexurônicos/químicaRESUMO
Recently, nanocarriers have been utilized for encapsulating and sustained release of agrochemicals specifically auxins. Due to their potential applications such as increased bioavailability and improved crop yield and nutritional quality. Herein, the efficacy of alginate/chitosan nanocapsules as a nanocarrier for the hormone indole-3-butyric acid (IBA) loading and its effect on rooting tobacco plants has been carried out in the present study. The average particle size of IBA-alginate/chitosan nanocapsules was measured by Dynamic light scattering analysis at 321 nm. Scanning electron microscope studies revealed the spherical shape of nanoparticles with an average size of 97 nm. The average particle size of IBA-alginate/chitosan nanocapsules was measured by Dynamic light scattering analysis at 321 nm. The characteristic peaks of IBA on alginate/chitosan nanocapsules were identified by Fourier transform infrared spectroscopic analysis. Also, high efficiency (35%) of IBA hormone loading was observed. The findings indicated that the concentration of 3 mgL-1 of IBA-alginate/chitosan nanocapsules has the highest efficiency in increasing the rooting in tobacco (Nicotiana tabacum) plants compared to other treatments. According to our results, we can introduce alginate/chitosan nanocapsules as an efficient nanocarrier in IBA hormone transfer applications and their use in agriculture.
Assuntos
Alginatos , Quitosana , Indóis , Nanocápsulas , Nicotiana , Raízes de Plantas , Quitosana/química , Nicotiana/efeitos dos fármacos , Nicotiana/crescimento & desenvolvimento , Nicotiana/metabolismo , Alginatos/química , Indóis/química , Nanocápsulas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Ácidos Hexurônicos/química , Ácido Glucurônico/química , Reguladores de Crescimento de Plantas/farmacologia , Reguladores de Crescimento de Plantas/químicaRESUMO
Calcined bone is an attractive natural material for use as a bone substitute because of its cost-effectiveness and high biocompatibility, which are comparable to that of synthetic hydroxyapatite. However, the calcination process has significantly weakened the mechanical properties. In this study, a composite of calcined bovine bone powder reinforced with silane cross-linked alginate was prepared to assess its biocompatibility, osteoconductivity, and mechanical compatibility as a bone substitute material. Culture studies with osteoblast-like cells (MC3T3-E1) showed no cytotoxicity toward the composite and exhibited general cell proliferative properties in its presence. In contrast, the composite reduced the alkaline phosphatase activity of osteoblasts but led to significant noncellular apatite deposition on the surface. In addition, quasi-static compression tests of the composite revealed mechanical properties comparable to those of human cancellous bone. The mechanical properties remained stable under wet conditions and did not deteriorate significantly even after 2 weeks of immersion in simulated body fluid at 37°C. The results show that this composite, composed of calcined bone powder and silane cross-linked alginate, is a promising bone substitute material with biocompatibility, osteoconductivity, and mechanical compatibility.
Assuntos
Alginatos , Substitutos Ósseos , Teste de Materiais , Osteoblastos , Silanos , Alginatos/química , Animais , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Camundongos , Bovinos , Osteoblastos/metabolismo , Osteoblastos/citologia , Silanos/química , Humanos , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Pós , Reagentes de Ligações Cruzadas/química , Linhagem CelularRESUMO
Interfibrillar phases and bonding in cellulose nanofibril (CNF)-based composites are crucial for materials performances. In this study, we investigated the influence of CNF surface characteristics, the guluronic acid/mannuronic acid ratio, and the molecular weight of alginates on the structure, mechanical, and barrier properties of CNF/alginate composite films. Three types of CNFs with varying surface charges and nanofibril dimensions were prepared from wood pulp fibers. The interfacial bonding through calcium ion cross-linking between alginate and carboxylated CNFs (TCNFs) led to significantly enhanced stiffness and strength due to the formation of an interpenetrating double network, compared to composites from alginates and CNFs with native negative or cationic surface charges. Various alginates extracted from Alaria esculenta (AE) and Laminaria hyperborea (LH) were also examined. The TCNF/AE composite, prepared from alginate with a high mannuronic acid proportion and high molecular weight, exhibited a Young's modulus of 20.3 GPa and a tensile strength of 331 MPa under dry conditions and a Young's modulus of 430 MPa and a tensile strength of 9.3 MPa at the wet state. Additionally, the TCNF/AE composite demonstrated protective properties as a barrier coating for fruit, significantly reducing browning of banana peels and weight loss of bananas stored under ambient conditions.
Assuntos
Alginatos , Celulose , Nanofibras , Resistência à Tração , Alginatos/química , Celulose/química , Nanofibras/química , Laminaria/química , Módulo de Elasticidade , Peso Molecular , Ácidos Hexurônicos/químicaRESUMO
Compact polyelectrolyte complexes (CoPECs) can exhibit mechanical properties similar to those of biological tissues and other interesting properties, such as self-healing. To date, a variety of CoPECs prepared from synthetic polyelectrolytes have been investigated, but there are very few examples based entirely on biopolymers. We describe here an investigation of CoPECs based on poly(l-lysine) (PLL) with sodium hyaluronate (HA) and alginate (Alg). A 2:1 ratio of cation:anion and 0.25 M NaBr was beneficial for the formation of viscoelastic PLL-HA CoPECs, with the favorable ratio attributed to the spacing of carboxylates on HA being one every two saccharide units. In contrast, 1.0 M NaBr and a 1:1 ratio were better for PLL-Alg CoPECs. Both CoPECs swelled or retained a constant volume when immersed in hypertonic media, but contracted in hypotonic media. The loading of molecules into the PLL-HA (2:1) CoPECs was investigated. Higher loadings were achieved for anionic molecules compared to cations, presumably due to the excess cationic binding sites on the networks. The times required for full release of the molecules ranged from less than 2 h for neutral paracetamol to about 48 h for crystal violet and diclofenac.
Assuntos
Alginatos , Ânions , Ácido Hialurônico , Polilisina , Polilisina/química , Ácido Hialurônico/química , Alginatos/química , Ânions/química , Eletrólitos/química , Ácidos Hexurônicos/química , Polissacarídeos/químicaRESUMO
To solve the problems existing in the clinical application of hypericin (Hyp) and tirapazamine (TPZ), a nano-drug delivery system with synergistic anti-tumor functions was constructed using mesoporous silica nanoparticles (MSN) and sodium alginate (SA). The system exhibited excellent stability, physiological compatibility and targeted drug release performance in tumor tissues. In the in vitro and in vivo experiments, Hyp released from MSN killed tumor cells through photodynamic therapy (PDT). The degree of hypoxia in the tumor tissue site was exacerbated, enabling TPZ to fully exert its anti-tumor activity. Our studies suggested that the synergistic effects between the components of the nano-drug delivery system significantly improve the anti-tumor properties of Hyp and TPZ.
Assuntos
Alginatos , Antracenos , Nanopartículas , Perileno , Dióxido de Silício , Tirapazamina , Microambiente Tumoral , Dióxido de Silício/química , Microambiente Tumoral/efeitos dos fármacos , Alginatos/química , Animais , Humanos , Tirapazamina/química , Tirapazamina/farmacologia , Nanopartículas/química , Perileno/análogos & derivados , Perileno/química , Perileno/farmacologia , Camundongos , Antracenos/química , Linhagem Celular Tumoral , Fotoquimioterapia , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Porosidade , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Sinergismo Farmacológico , Sistemas de Liberação de Fármacos por Nanopartículas/químicaRESUMO
The degradation of sodium alginate by human gut microbiota was found to be retarded via calcium cross-linking in our previous study. We hypothesized that the guluronic acid block (GB) on the alginate molecule might be the key structural region affecting alginate degradation by the gut microbiota when cross-linked with calcium. This study aims to prove this hypothesis by studying the structural features of the cross-linked GB on its in vitro fecal fermentation behaviors concerning the aspects of total carbohydrate contents, monosaccharide contents, short-chain fatty acids production, calcium state variations, and structural variations. Herein, GB isolated from sodium alginate was cross-linked under ranges of molar ratios of [Ca2+]/[-COOH] that further restricted the degradation by gut microbiota similar to the cross-linked alginates. First, total carbohydrate contents, short-chain fatty acids production, monosaccharides contents, and calcium state analyses confirmed that the degradation of GB by gut microbiota was restricted by calcium cross-linking. Furthermore, the tracking analysis of structural variations during in vitro fermentation revealed that the "granules" structure could further restrict degradation by the gut microbiota, leaving more cross-linked GB fragments surviving in comparison to the "networks" structure. In addition, Bacteroides xylanisolvens showed a significant positive correlation to the "cross-linking porosity (R = 0.825, p < 0.001), which supported our previous findings on fermentation behaviors of cross-linked alginate. Together, guluronic acid blocks are the key structural regions that retard the degradation of sodium alginate by the gut microbiota when cross-linked with calcium.
Assuntos
Alginatos , Cálcio , Colo , Fermentação , Microbioma Gastrointestinal , Ácidos Hexurônicos , Alginatos/química , Humanos , Colo/metabolismo , Colo/microbiologia , Cálcio/metabolismo , Ácidos Hexurônicos/química , Fezes/microbiologia , Ácidos Graxos Voláteis/metabolismoRESUMO
In present study, whey protein isolate fibrils and sodium alginate complexes (WPIFs-SA) were prepared and further used to stabilize Pickering emulsions for lycopene delivery. The optimal interaction between WPIFs and SA occurred at pH 3.0, with a mass ratio of 2:1. Increasing the oil fractions and the content of WPIFs-SA complexes significantly improved Pickering emulsions' stability, concurrently reducing droplet size and increasing viscoelasticity. Meanwhile, it facilitated the formation of a thicker protective layer and a compact network structure around the oil droplets, offering better protection for lycopene against thermal and photo degradation. In vitro digestion studies revealed that as the oil fractions and complex contents increased, the lipolysis degree decreased. The engineered WPIFs-SA Pickering emulsion could be used as an innovative delivery system for the protection and delivery of lycopene.
Assuntos
Alginatos , Emulsões , Licopeno , Proteínas do Soro do Leite , Proteínas do Soro do Leite/química , Alginatos/química , Licopeno/química , Concentração de Íons de Hidrogênio , Digestão , Viscosidade , Tamanho da Partícula , Carotenoides/química , Lipólise , Ácido Glucurônico/química , Ácidos Hexurônicos/químicaRESUMO
This study examined the impacts of ultrasonic power (0, 150, 300, 450, 600, and 750 W) and ultrasonic durations (3, 6, 9, 12, and 15 min) on the physicochemical properties and microstructure of diacylglycerol (DAG)-loaded emulsions stabilized with soybean protein isolate (SPI) and sodium alginate (SA). The findings indicated that the smallest particle size, zeta potential, and contact angle for SPI-SA-DAG emulsions were respectively 5.58 µm, -49.85 mV, and 48.65°, achieved at an ultrasonic power of 450 W. The emulsification properties, loss modulus, storage modulus, and apparent viscosity of the emulsions were optimal at this power setting and at a duration of 9 min. Analytical techniques, including confocal laser scanning-, scanning electron-, and atomic force microscopy, revealed that ultrasonication significantly altered emulsion aggregation state, with the surface roughness (Rq) being minimized at 450 W. These results demonstrated that the stability of SPI-SA-DAG emulsions can be effectively enhanced by an appropriate ultrasonic treatment at 450 W for 9 min. This research provides theoretical support for the broad application of sonication techniques in the food industry.
Assuntos
Alginatos , Diglicerídeos , Emulsões , Proteínas de Soja , Alginatos/química , Proteínas de Soja/química , Diglicerídeos/química , Sonicação , Ácidos Hexurônicos/química , Ácido Glucurônico/química , Fenômenos Químicos , Tamanho da Partícula , Ondas UltrassônicasRESUMO
Guided bone regeneration (GBR) is a widely used procedure that prevents the fast in-growth of soft tissues into bone defect. Among the different types of membranes, the use of collagen membranes is the gold standard. However, these membranes are implanted in tissue location where a severe acute inflammation will occur and can be negatively affected. The aim of this study was to develop a collagen-based membrane for GBR that incorporated alginate-hydroxyapatite microparticles. Membranes were manufactured using collagen type I and gelatin and alginate-hydroxyapatite microparticles. Membranes were assessed in terms of topography by scanning electron microscopy and confocal microscopy; stability by swelling after an overnight incubation in saline and enzymatic degradation against collagenase and mechanical properties by tensile tests. Furthermore, the biological response was assessed with SaOs-2 cells and THP-1 macrophages to determine alkaline phosphatase activity and inflammatory cytokine release. Our results showed that the incorporation of different percentages of these microparticles could induce changes in the surface topography. When the biological response was analyzed, either membranes were not cytotoxic to THP-1 macrophages or to SaOs-2 cells and they did not induce the release of pro-inflammatory cytokines. However, the different surface topographies did not induce changes in the macrophage morphology and the release of pro- and anti-inflammatory cytokines, suggesting that the effect of surface roughness on macrophage behavior could be dependent on other factors such as substrate stiffness and composition. Collagen-gelatin membranes with embedded alginate-hydroxyapatite microparticles increased ALP activity, suggesting a positive effect of them on bone regeneration, remaining unaffected the release of pro- and anti-inflammatory cytokines.
Assuntos
Alginatos , Regeneração Óssea , Durapatita , Inflamação , Osteoblastos , Regeneração Óssea/efeitos dos fármacos , Humanos , Osteoblastos/efeitos dos fármacos , Osteoblastos/citologia , Durapatita/química , Durapatita/farmacologia , Alginatos/química , Inflamação/patologia , Propriedades de Superfície , Gelatina/química , Macrófagos/metabolismo , Regeneração Tecidual Guiada/métodos , Membranas Artificiais , Tamanho da Partícula , Citocinas/metabolismo , Colágeno Tipo I/química , Colágeno Tipo I/metabolismo , Colágeno Tipo I/farmacologia , Ácido Glucurônico/química , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/química , Ácidos Hexurônicos/farmacologiaRESUMO
Carvacrol has demonstrated antioxidant activity; however, its high volatility and low water solubility limit its direct application in food matrices. Then, an effective encapsulation system is required to protect it. This study aimed to design and characterize a carvacrol-based additive encapsulated in a spray-dried multilayer emulsion based on chitosan/sodium alginate/maltodextrin. Spray-drying temperature of 120 °C and 3 %(w/w) maltodextrin content maximized both encapsulation efficiency (~97 %) and loading capacity (~53 %). The powder's antioxidant properties were evaluated in two food simulant media: water (SiW) and water-ethanol (SiD). The highest antioxidant activity was observed in SiW for both ABTSâ¢+ (8.2 ± 0.3mgEAG/g) and FRAP (4.1 ± 0.2mgEAG/g) methods because of the reduced release of carvacrol in SiD vs. SiW, as supported by micro- and macrostructural observations by SAXS and microscopy, respectively. An increase from 143 to 157 °C attributable to carvacrol protection and Tg = 44.4 °C (> ambient) were obtained by TGA and DSC, respectively. FT-IR confirmed intermolecular interactions (e.g. -COO- and -NH3+) as well as H-bonding formation. High water solubility (81 ± 3 %), low hygroscopicity (8.8 ± 0.2 %(w/w), poor flowability (CI:45 ± 4), and high cohesiveness (HR:1.8 ± 0.1) between particles were achieved, leading to a powdered antioxidant additive with high potential for applications which required avoiding/reducing oxidation on hydrophilic and hydrophobic food products.
Assuntos
Alginatos , Antioxidantes , Quitosana , Cimenos , Emulsões , Polissacarídeos , Pós , Quitosana/química , Antioxidantes/química , Antioxidantes/farmacologia , Cimenos/química , Alginatos/química , Emulsões/química , Polissacarídeos/química , Ácido Glucurônico/química , Ácidos Hexurônicos/químicaRESUMO
We have successfully created self-assembled membranes by combining positively charged (Pro-X-(Phe-X)5-Pro) PFX peptides with negatively charged alginate. These PFX/alginate membranes were formed by three different peptides that contain either X = Arginine (R), Histidine (H), or Ornithine (O) as their charged amino acid. The assemblies were compared to membranes that were previously reported by us composed of X = lysine (K). This study enabled us to elucidate the impact of amino acids' specific interactions on membrane formation. SEM, SAXS, and cryo-TEM measurements show that although K, R, H, and O may have a similar net charge, the specific traits of the charged amino acid is an essential factor in determining the hierarchical structure of alginate/PFX self-assembled membranes.
Assuntos
Alginatos , Alginatos/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Peptídeos/química , Cátions/química , Membranas Artificiais , Arginina/químicaRESUMO
Microalgae immobilization in alginate beads shows promise for biomass production and water pollution control. However, carrier instability and mass transfer limitations are challenges. This study introduces buoyant barium alginate bubble beads (BABB), which offer exceptional stability and enhance Chlorella vulgaris growth. In just 12 days, compared to traditional calcium alginate beads, BABB achieved a 20 % biomass increase while minimizing cell leakage and simplifying harvesting. BABB optimization involved co-immobilization with BG-11 medium, enrichment of CO2 in internal bubbles, and the integration of Fe nanoparticles (FeNPs). In the open raceway pond reactor, these optimizations resulted in a 39 % increase in biomass over 7 days compared to the unoptimized setup in closed flasks. Furthermore, enhancements in pigment and organic matter production were observed, along with improved removal of ammonia nitrogen and phosphate. These results highlight the overall advantages of BABB for microalgae immobilization, offering a scientific foundation for their effective utilization.
Assuntos
Alginatos , Chlorella vulgaris , Ácido Glucurônico , Chlorella vulgaris/crescimento & desenvolvimento , Alginatos/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Biomassa , Células Imobilizadas/metabolismo , Bário/química , Microalgas/crescimento & desenvolvimento , Microesferas , Reatores Biológicos , Dióxido de CarbonoRESUMO
This paper focuses on the preparation and characterization of antibacterial alginate microparticles containing silver@hydroxyapatite functionalized calcium carbonate composites for tissue engineering. Microparticles were prepared by cross-linking a silver@composite sodium alginate dispersion with CaCl2. This method showed a very good silver efficiency loading and the presence of silver chloride nanoparticles was detected. Silver free microparticles, containing hydroxyapatite functionalized calcium carbonates and neat alginate microparticles were prepared as well. All microparticles were characterized for water absorption and for in vitro bioactivity by immersion in simulated body fluid (SBF). Finally, antimicrobial and antibiofilm activities as well as cytotoxicity were evaluated. Microparticles containing silver@composites exhibited good antimicrobial and antibiofilm activities against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans, but exerted a certain cytotoxicity against the tested cell models (fibroblasts and osteoblasts). Microparticles containing hydroxyapatite functionalized calcium carbonates were found to be always less cytotoxic, also in comparison to neat alginate microparticles, proving that the presence of the inorganic matrices exerts a protective effect on microparticle cytotoxicity.
Assuntos
Alginatos , Antibacterianos , Carbonato de Cálcio , Durapatita , Prata , Alginatos/química , Durapatita/química , Prata/química , Prata/farmacologia , Carbonato de Cálcio/química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Fibroblastos/efeitos dos fármacos , Animais , Linhagem Celular , Humanos , Compostos de Prata/química , Compostos de Prata/farmacologia , Candida albicans/efeitos dos fármacos , CamundongosRESUMO
Ulcerative colitis (UC) is a chronic bowel inflammatory disease affecting the colorectum. Epidermal growth factor (EGF) has been demonstrated to be effective to counteract UC. However, there exists the gastrointestinal challenges such as stomach acid, enzyme and bile salts for oral delivery of EGF. Herein, calcium alginate microsphere was prepared by the microfluidic technique to encapsulate EGF. The morphology of EGF-loaded microsphere (MS-EGF) was spherical and its average particle size was 80 ± 23 µm. The encapsulation efficiency of EGF was reaching to 93.8 % ± 1.6 %. In vitro release experiments showed that MS-EGF presented the good pH-sensitive properties, that was, it could effectively resist the gastric acid and small intestinal fluids, and undergone the rapid dissolution in the artificial colon fluid. In vitro cellular experiments demonstrated that the bioactivity of EGF was well preserved by microsphere. Moreover, in vivo murine colitis model showed that MS-EGF presented the obvious colitis alleviation. Furthermore, the colonic morphology of colitis mice was effectively recovered and the tight junction between the gut epithelium was obviously repaired. In conclusion, calcium alginate microsphere might be a promising vehicle of EGF for UC treatment.
Assuntos
Alginatos , Colite Ulcerativa , Fator de Crescimento Epidérmico , Mucosa Intestinal , Microesferas , Animais , Alginatos/química , Alginatos/administração & dosagem , Colite Ulcerativa/tratamento farmacológico , Fator de Crescimento Epidérmico/administração & dosagem , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Camundongos , Administração Oral , Masculino , Liberação Controlada de Fármacos , Humanos , Tamanho da Partícula , Colo/metabolismo , Colo/efeitos dos fármacos , Colo/patologia , Portadores de Fármacos/química , Modelos Animais de Doenças , Ácidos Hexurônicos/química , Ácidos Hexurônicos/administração & dosagemRESUMO
Microspheres are micrometer-sized particles that can load and gradually release drugs via physical encapsulation or adsorption onto the surface and within polymers. In the field of biomedicine, hydrogel microspheres have been extensively studied for their application as drug carriers owing to their ability to reduce the frequency of drug administration, minimize side effects, and improve patient compliance. Sodium alginate (ALG) is a naturally occurring linear polysaccharide with three backbone glycosidic linkages. There are two auxiliary hydroxyl groups present in each of the moieties of the polymer, which have the characteristics of an alcohol hydroxyl moiety. The synthetic ALG units can undergo chemical cross-linking reactions with metal ions, forming a cross-linked network structure of polymer stacks, ultimately forming a hydrogel. Hydrogel microspheres can be prepared using a simple process involving the ionic cross-linking properties of ALG. In this study, we prepared ALG-based hydrogel microspheres (ALGMS) using a microfluidic electrodeposition strategy. The prepared hydrogel microspheres were uniformly sized and well-dispersed, owing to accurate control of the microfluidic electrospray flow. ALGMS cross-linked with different metal ions were prepared using a microfluidic electrospray technique combining microfluidic and high electric field, and its antimicrobial properties, slow drug release ability, and biocompatibility were investigated. This technology holds promise for application in advanced drug development and production.
Assuntos
Alginatos , Microesferas , Alginatos/química , Reagentes de Ligações Cruzadas/química , Hidrogéis/química , Técnicas Analíticas Microfluídicas/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Portadores de Fármacos/químicaRESUMO
The extraction of cannabinoids from the inflorescence and leaves of Cannabis sativa L. is gaining interest from researchers, in addition to addressing the under-utilization of the by-products in the stems and roots of the trees. The present study investigated the recovery of pectin from the left-over parts of hemp tress using an eco-friendly method with the aid of organic acids. Different cannabis cultivars-Chalotte's Angels (CHA) and Hang-Krarog (HKR)-were used as plant materials. The stems of both cannabis cultivars contained more pectin than the roots, and tartaric acid-aided extraction provided higher yields than from citric acid. Extracting the acid solution affected some characteristics, thereby differentiating the functional properties of the derived pectin. Extraction using tartaric acid provided pectin with a higher galacturonic acid content, whereas pectin with a higher methylation degree could be prepared using citric acid. The pectin samples extracted from the stems of CHA (P-CHA) and HKR (P-HKR) had low methoxyl pectin. P-CHA had better free radical scavenging capability, whereas P-HKR showed more potent reducibility. Considering the functional properties, P-CHA showed greater emulsion formability and foaming activity, whereas P-HKR possessed a better thickening effect. The present work suggests the feasible utilization of P-CHA and P-HKR as food additives with bioactivity.
Assuntos
Cannabis , Pectinas , Extratos Vegetais , Pectinas/química , Pectinas/isolamento & purificação , Cannabis/química , Extratos Vegetais/química , Ácido Cítrico/química , Folhas de Planta/química , Caules de Planta/química , Tartaratos/química , Raízes de Plantas/química , Ácidos Hexurônicos/química , Ácidos Hexurônicos/análiseRESUMO
Nonhealing infectious wounds, characterized by bacterial colonization, wound microenvironment destruction, and shape complexity, present an intractable problem in clinical practice. Inspired by LEGOs, building-block toys that can be assembled into desired shapes, we proposed the use of electrospray nano-micro composite sodium alginate (SA) microspheres with antibacterial and angiogenic properties to fill irregularly shaped wounds instantly. Specifically, porous poly(lactic-co-glycolic acid) (PLGA) microspheres (MSs) encapsulating basic fibroblast growth factor (bFGF) were produced by a water-in-oil-in-water double-emulsion method. Then, bFGF@MSs were blended with the SA solution containing ZIF-8 nanoparticles. The resultant solution was electrosprayed to obtain nano-micro composite microspheres (bFGF@MS/ZIF-8@SAMSs). The composite MSs' size could be regulated by PLGA MS mass proportion and electrospray voltage. Moreover, bFGF, a potent angiogenic agent, and ZIF-8, bactericidal nanoparticles, were found to release from bFGF@MS/ZIF-8@SAMSs in a controlled and sustainable manner, which promoted cell proliferation, migration, and tube formation and killed bacteria. Through experimentation on rat models, bFGF@MS/ZIF-8@SAMSs were revealed to adapt to wound shapes and accelerate infected wound healing because of the synergistic effects of antibacterial and angiogenic abilities. In summation, this study developed a feasible approach to prepare bioactive nano-micro MSs as building blocks that can fill irregularly shaped infected wounds and improve healing.
Assuntos
Alginatos , Antibacterianos , Fator 2 de Crescimento de Fibroblastos , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Cicatrização , Alginatos/química , Antibacterianos/química , Antibacterianos/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Ratos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Fator 2 de Crescimento de Fibroblastos/química , Fator 2 de Crescimento de Fibroblastos/farmacologia , Humanos , Ratos Sprague-Dawley , Staphylococcus aureus/efeitos dos fármacos , Masculino , Escherichia coli/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Ácidos Hexurônicos/química , Ácidos Hexurônicos/farmacologia , Células Endoteliais da Veia Umbilical Humana , Testes de Sensibilidade Microbiana , Proliferação de Células/efeitos dos fármacos , Ácido Glucurônico/química , Ácido Glucurônico/farmacologiaRESUMO
Obtaining high-added value compounds from agricultural waste receives increasing attention, as it can both improve resource utilization efficiency and reduce waste generation. In this study, polysaccharides are extracted from the discarded roots of Abelmoschus manihot (L.) by the high-efficiency ultrasound-assisted extraction (UAE). The optimized condition was determined as solid-liquid ratio SL ratio = 1:20, temperature T = 30 °C and time T = 40 min, achieving an extraction yield of 13.41%. Composition analysis revealed that glucose (Glc, 44.65%), rhamnose (Rha, 26.30%), galacturonic acid (GalA, 12.50%) and galactose (Gal, 9.86%) are the major monosaccharides of the extract. The extract showed a low degree of esterification (DE) value of 40.95%, and its Fourier-transform infrared (FT-IR) spectrum exhibited several characteristic peaks of polysaccharides. Inspired by the wide cosmetic applications of polysaccharides, the skincare effect of the extract was evaluated via the moisture retention, total phenolic content (TPC) quantification, 2,2-Diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging activity, anti-hyaluronidase and anti-elastase activity experiments. The extract solutions demonstrated a 48 h moisture retention rate of 10.75%, which is superior to that of commercially available moisturizer hyaluronic acid (HA). Moreover, both the TPC value of 16.16 mg GAE/g (dw) and DPPH-free radical scavenging activity of 89.20% at the concentration of 2 mg/mL indicated the strong anti-oxidant properties of the extract. Furthermore, the anti-hyaluronidase activity and moderate anti-elastase activity were determined as 72.16% and 42.02%, respectively. In general, in vitro skincare effect experiments suggest moisturizing, anti-oxidant, anti-radical and anti-aging activities of the A. manihot root extract, indicating its potential applications in the cosmetic industry.