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1.
Int J Nanomedicine ; 14: 5187-5199, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371955

RESUMO

Introduction and objective: Previous studies indicate that miltefosine (MFS) may be an alternative as an antifungal agent; however, it presents several adverse effects. Thus, the aim of this study was to produce miltefosine-loaded alginate nanoparticles (MFS.Alg) for toxicity reduction to be used as an alternative for the treatment of cryptococcosis and candidiasis. Methods: Alginate nanoparticles were produced using the external emulsification/gelation method, and their physicochemical and morphological characteristics were analyzed. MFS encapsulation efficiency, release assay and toxicity on red blood cells and on Galleria mellonella larvae were assessed. The antifungal activity was evaluated using in vitro and in vivo larval models of G. mellonella infected with Candida albicans (SC5314 and IAL-40), Cryptococcus neoformans H99 and Cryptococcus gattii ATCC 56990. The treatment efficacy was evaluated by survival curve, colony forming unit (CFU) counting and histopathological analysis. Results: MFS.Alg nanoparticles presented a mean size of 279.1±56.7 nm, a polydispersity index of 0.42±0.15 and a zeta potential of -39.7±5.2 mV. The encapsulation efficiency of MFS was 81.70±6.64%, and its release from the nanoparticles occurred in a sustained manner. MFS in alginate nanoparticles presented no hemolytic effect and no toxicity in G. mellonella larvae. Treatment with MFS.Alg extended the survival time of larvae infected with C. albicans and C. gattii. In addition, the fungal burden reduction was confirmed by CFU and histopathological data for all groups treated with 200 mg/Kg of MFS.Alg. Conclusion: These results support the use of alginate-based drug delivery systems as carriers for MFS for drug toxicity reduction and control of the fungal infection in the in vivo model of G. mellonella.


Assuntos
Alginatos/química , Candidíase/tratamento farmacológico , Criptococose/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Fosforilcolina/análogos & derivados , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida albicans/efeitos dos fármacos , Candidíase/microbiologia , Criptococose/microbiologia , Liberação Controlada de Fármacos , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Fosforilcolina/farmacologia , Fosforilcolina/uso terapêutico , Fosforilcolina/toxicidade , Ovinos
2.
J Agric Food Chem ; 67(37): 10481-10488, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31433940

RESUMO

Here, we report two methods that chemically modify alginate to achieve neutral-basic pH sensitivity of the resultant hydrogel. The first method involves direct amide bond formation between alginate and 4-(2-aminoethyl)benzoic acid. The second method that arose out of the desire to achieve better control of the degradation rate of the alginate hydrogel involves reductive amination of oxidized alginate. The products of both methods result in a hydrogel vehicle for targeted delivery of encapsulated payload under physiological conditions in the gastrointestinal tract. Two-dimensional diffusion-ordered spectroscopy and internal and coaxial external nuclear magnetic resonance standards were used to establish chemical bonding and percent incorporation of the modifying groups into the alginate polymer. The hydrogel made with alginate modified by each method was found to be completely stable under acidic pH conditions while disintegrating within minutes to hours in neutral-basic pH conditions. We found that, while alginate oxidation did not affect the ß-d-mannuronate/α-l-guluronate ratio of alginate, the rate of disintegration of the hydrogel made with oxidized alginate was dependent upon the degree of oxidation.


Assuntos
Alginatos/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/instrumentação , Administração Oral , Difusão , Hidrogéis/química , Concentração de Íons de Hidrogênio , Oxirredução , Polímeros/química
3.
Zhongguo Yi Liao Qi Xie Za Zhi ; 43(4): 275-278, 2019 Jul 30.
Artigo em Chinês | MEDLINE | ID: mdl-31460720

RESUMO

Using three-dimensional printing to produce antibacterial wound dressing is a new topic that will change the production style of wound dressing industry. Combining with post-3D-printed process, a desktop fused deposition molding equipment can be used to produce wound dressing containing polyvinyl alcohol, alginate and chitosan. The wound dressing produced by FDM has good aspects of absorbency, moisture vapour transmission rate and mechanical property. After loaded with antibacterial agent iodine and silver nano particle, the antibacterial activity rate increases to 99% and it is suitable to use as antibacterial wound dressing. This method affects the production of wound dressing to a more cost-effective way, and provides a possible individualized treatment for patient in the future.


Assuntos
Antibacterianos , Bandagens , Impressão Tridimensional , Cicatrização , Alginatos/química , Antibacterianos/administração & dosagem , Bactérias/efeitos dos fármacos , Bandagens/economia , Bandagens/normas , Quitosana/química , Humanos , Iodo/administração & dosagem , Iodo/farmacologia , Nanopartículas/administração & dosagem , Álcool de Polivinil/química , Prata/administração & dosagem , Prata/farmacologia
4.
Int J Nanomedicine ; 14: 4559-4571, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31417258

RESUMO

Background and objective: Tetracycline and its derivatives, combined with calcium phosphates, have been proposed as a delivery system to control inflammatory processes and chronic infections. The objective of this study was to evaluate the microspheres of alginate encapsulated minocycline-loaded nanocrystalline carbonated hydroxyapatite (CHAMINO) as a biomimetic device to carry out target-controlled drug delivery for alveolar bone repair. Methods: CHAMINO microspheres were implanted in a rat central incisor socket after 7 and 42 days. New bone was formed in both groups between 7 and 42 days of implantation. However, the bone growth was significantly higher for the CHAMINO microspheres. Results: The minocycline (MINO) loading capacity of the nanocrystaline carbonated hydroxyapatite (CHA) nanoparticles was 25.1±2.2 µg MINO/mg CHA for adsorption over 24 hrs. The alginate microspheres containing minocycline-loaded CHA were biologically active and inhibited the Enterococcus faecalis culture growth for up to seven days of the MINO release. An osteoblastic cell viability assay based on the resazurin reduction was conducted after the cells were exposed to the CHAMINO powder and CHAMINO microspheres. Thus, it was found that the alginate extracts encapsulated the minocycline-loaded CHA microspheres and did not affect the osteoblastic cell viability, while the minocycline-doped CHA powder reduced the cell viability by 90%. Conclusion: This study concluded that the alginate microspheres encapsulating the minocycline-loaded nanocrystalline carbonated hydroxyapatite exhibited combined antibacterial activity against Enterococcus faecalis with cytocompatibility and osteoconduction properties. The significant improvement in the new bone formation after 42 days of implantation suggests that the CHAMINO microsphere has potential in clinical applications of bone regeneration.


Assuntos
Alginatos/química , Regeneração Óssea/efeitos dos fármacos , Carbonatos/química , Durapatita/química , Microesferas , Minociclina/farmacologia , Nanopartículas/química , Animais , Antibacterianos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Enterococcus/efeitos dos fármacos , Humanos , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Osteoblastos/efeitos dos fármacos , Ratos Wistar , Difração de Raios X
5.
J Agric Food Chem ; 67(36): 10000-10009, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31442045

RESUMO

Improving plant resistance against systemic diseases remains a challenging research topic. In this study, we developed a dual-action pesticide-loaded hydrogel with the capacity to significantly induce plant resistance against tobacco mosaic virus (TMV) infection and promote plant growth. We produced an alginate-lentinan-amino-oligosaccharide hydrogel (ALA-hydrogel) by coating the surface of an alginate-lentinan drug-loaded hydrogel (AL-hydrogel) with amino-oligosaccharide using electrostatic action. We determined the formation of the amino-oligosaccharide film using various approaches, including Fourier transform infrared spectrometry, the ζ potential test, scanning electron microscopy, and elemental analysis. It was found that the ALA-hydrogel exhibited stable sustained-release activity, and the release time was significantly longer than that of the AL-hydrogel. In addition, we demonstrated that the ALA-hydrogel was able to continuously and strongly induce plant resistance against TMV and increase the release of calcium ions to promote Nicotiana benthamiana growth. Meanwhile, the ALA-hydrogel maintained an extremely high safety to organisms. Our findings provide an alternative to the traditional approach of applying pesticide for controlling plant viral diseases. In the future, this hydrogel with the simple synthesis method, green synthetic materials, and its efficiency in the induction of plant resistance will attract increasing attention and have good potential to be employed in plant protection and agricultural production.


Assuntos
Antivirais/química , Preparações de Ação Retardada/farmacologia , Portadores de Fármacos/química , Lentinano/química , Lentinano/farmacologia , Doenças das Plantas/virologia , Vírus do Mosaico do Tabaco/fisiologia , Tabaco/virologia , Alginatos/química , Antivirais/farmacologia , Preparações de Ação Retardada/química , Resistência à Doença , Hidrogéis/química , Doenças das Plantas/imunologia , Tabaco/imunologia
6.
Food Chem ; 298: 125045, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31261002

RESUMO

In this study, sacha inchi oil (SIO) (Plukenetia volubilis L.) was microencapsulated via complex coacervation of ovalbumin (OVA) and sodium alginate (AL), and the microcapsule properties were characterized. The omega-3 content in the SIO was evaluated after in vitro gastric simulation and microencapsulation. The coacervate complex between OVA and AL was evaluated based on electrostatic interactions and developed for use as a wall material via the SIO microencapsulation process. The best mass ratio for the biopolymers (OVA:AL) was 4:1 at pH 3.8, and the complex exhibited a thermal resistance at 189.86 °C. The SIO microcapsules showed a high encapsulation efficiency of approximately 94.12% in the ratio (OVA:AL) of 1:1. Furthermore, microencapsulated SIO presented resistance under gastric conditions with a low release of acyl (ω-3) units. These results demonstrate that it is possible to use OVA:AL as encapsulating agents to protect bioactive compounds and to improve the thermal behavior of microcapsules.


Assuntos
Composição de Medicamentos/métodos , Euphorbiaceae/metabolismo , Óleos Vegetais/química , Alginatos/química , Varredura Diferencial de Calorimetria , Cápsulas/química , Euphorbiaceae/química , Ácidos Graxos Ômega-3/química , Concentração de Íons de Hidrogênio , Ovalbumina/química , Eletricidade Estática
7.
Food Chem ; 299: 125109, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31295635

RESUMO

The aim of this research is to develop, characterize and utilize a multi-layer antibacterial film using chitosan (CS) and sodium alginate (SA) as biopolymers and cinnamon essential oil (CEO) as main antibacterial ingredients. The dense cross-section of SA layer in the scanning electron microscopy (SEM) analysis verified that layer-by-layer method improved physical and mechanical properties of CS-CEO single layer film. The thermogravimetric (TGA) and fourier transform infrared (FT-IR) analysis indicated that the layer-by-layer method changed the intermolecular interaction and the thermal stability. Importantly, the multi-layer film exhibited more sustained release and higher retention rate of CEO compared CS-CEO single layer film. The multi-layer coating showed a more significant and lasting inhibition of penicillium expansion which further demonstrated that the layer-by-layer method improved the release and retention of CEO in the multiphased system. To summarize, the multilayer film system is a promising controllable release system for loading essential oils.


Assuntos
Antifúngicos/farmacologia , Cinnamomum zeylanicum/química , Malus/microbiologia , Óleos Voláteis/farmacologia , Penicillium/efeitos dos fármacos , Alginatos/química , Antifúngicos/química , Quitosana/química , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacologia , Frutas/efeitos dos fármacos , Frutas/microbiologia , Malus/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Óleos Voláteis/farmacocinética , Penicillium/patogenicidade , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termogravimetria
8.
BMC Infect Dis ; 19(1): 568, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262260

RESUMO

BACKGROUND: With the aim of preparing a more effective, safe and economical vaccine for tuberculosis, inhalable live mycobacterium formulations were evaluated. METHODS: Alginate particles in the size range of 2-4 µm were prepared by encapsulating live Bacille Calmette-Guérin (BCG) and "Mycobacterium indicus pranii" (MIP). These particles were characterized for their size, stability and release profile. Mice were immunized with liquid aerosol or dry powder aerosol (DPA) alginate encapsulated mycobacterium particles and their in-vitro recall response and infection with mycobacterium H37Rv were investigated. RESULTS: It was found that the DPA of alginate encapsulated mycobacterium particles invoked superior immune response and provided higher protection in mice than the liquid aerosol. The BCG encapsulated in alginate particles (BEAP) and MIP encapsulated in alginate particles (MEAP) were engulfed by bone marrow dendritic cells (BMDCs) and co-localized with lysosome. The MEAP/BEAP activated BMDCs exhibited higher chemotaxis movement and had enhanced ability of antigen presentation to T cells. The in-vitro recall response of BEAP/MEAP immunized mice when compared in terms of proliferation index and Interferon gamma (IFN-gamma) released by splenocytes and mediastinal lymph node cells was found to be higher than mice immunized by liquid aerosol of BCG/MIP. Finally, different groups of immunized mice were infected with M. tb H37Rv and after 16 weeks the Colony forming units (CFUs) in lung and spleen estimated. The bacilli burden in the BEAP/MEAP immunized mice was significantly less than the respective liquid aerosol immunized mice and the histopathology of BEAP/MEAP immunized mice lungs showed very little damage. CONCLUSIONS: These inhale-able vaccines formulation of alginate coated live mycobacterium are more immunogenic as compared to the aerosol of bacilli and they provide better protection in mice when infected with H37Rv.


Assuntos
Aerossóis/administração & dosagem , Pulmão/imunologia , Vacinas contra a Tuberculose/farmacologia , Tuberculose/prevenção & controle , Alginatos/química , Animais , Vacina BCG/imunologia , Sistemas de Liberação de Medicamentos/métodos , Interferon gama/imunologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Complexo Mycobacterium avium/química , Complexo Mycobacterium avium/imunologia , Mycobacterium bovis/química , Mycobacterium bovis/imunologia , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Baço/microbiologia , Linfócitos T/imunologia , Linfócitos T/microbiologia , Tuberculose/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/imunologia , Vacinação/métodos
9.
Food Chem ; 300: 125174, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31330370

RESUMO

This paper focuses on the use of a new type of yeast encapsulation procedure, applying the chitosan-calcium alginate double layer microcapsules, for the production of Riesling sparkling wine. Four different sparkling wines were produced by free or encapsulated yeasts. The four types of yeast used were adapted (Free EtOH-A, Encapsulated EtOH-A) and non-adapted to ethanol (Free, Encapsulated). The different yeast-inoculating formats had a significant impact on oxygen consumption and pressure increase rate in the bottle during the prise de mousse. Similarly to the free form, encapsulated yeast successfully completed the secondary fermentation. After an ageing period of 6 months, volatiles and sensory profiles of sparkling wines were compared. Although, some differences in volatile profiles were found among samples, sparkling wines produced by Encapsulated EtOH-A showed sensory properties, in terms of aroma, taste and body, similar to those produced by free yeast (both adapted and non-adapted to ethanol).


Assuntos
Alginatos/química , Quitosana/química , Saccharomyces cerevisiae/fisiologia , Vinho/microbiologia , Adulto , Idoso , Cápsulas , Etanol/química , Etanol/farmacologia , Feminino , Fermentação , Humanos , Masculino , Pessoa de Meia-Idade , Odorantes , Pressão , Saccharomyces cerevisiae/efeitos dos fármacos , Paladar , Compostos Orgânicos Voláteis/análise , Vinho/análise
10.
Food Chem ; 298: 125023, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260964

RESUMO

This research investigated the effect of pH on forming electrostatic complexes between lentil protein isolate (LPI) and a range of anionic polysaccharides [carboxymethyl cellulose (CMC), gum Arabic (GA), alginate (AL), and ι-carrageenan (CAR)] at 4:1 LPI-polysaccharide mixing ratio, and their resulting emulsifying abilities. Maximum optical densities were found to be 0.486, 0.716, 0.310, and 0.190 for LPI-CMC, LPI-GA, LPI-AL, and LPI-CAR, respectively indicating the level of aggregate size and growth. LPI-CAR emulsion displayed the highest emulsion stability (ES) because of its higher continuous phase and emulsion viscosities, lower mean droplet sizes, and negatively charged droplets. They also formed much smaller complexes within solution due to their high negative charge. All other LPI-polysaccharide systems formed less stable emulsions than LPI alone due to the larger sizes of both complexes and oil droplets.


Assuntos
Ânions/química , Lens (Planta)/química , Proteínas de Plantas/química , Polissacarídeos/química , Alginatos/química , Carboximetilcelulose Sódica/química , Carragenina/química , Emulsões , Goma Arábica/química
11.
Food Chem ; 299: 125142, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31325715

RESUMO

Alginate lyases can be used for alginate oligosaccharide production and for structural characterization or modification of alginates. For these applications it is important to obtain detailed information on mode of action and substrate specificities of alginate lyases. In this study, five alginate lyase genes were cloned from Cellulophaga algicola DSM 14237 genomic DNA, heterologously expressed, and characterized by using HPSEC-RI and HPAEC-PAD/MS. It was demonstrated that these analytical approaches can provide detailed information on preferred substrates, extent of hydrolysis, and the liberated products. The recombinant enzymes cleaved alginates endolytically (CaAly1, CaAly2, CaAly3) or exolytically (CaAly4, CaAly5). The three endolytic alginate lyases predominantly hydrolyzed guluronic acid-rich alginates, only CaAly1 also showed activity on mannuronic acid-rich alginates. The oligosaccharide profiles further demonstrated that the endolytic enzymes have rather narrow but slightly different substrate specificities and that the two exolytic alginate lyases mainly cleaved unsaturated guluronic acid oligosaccharides to monomers.


Assuntos
Alginatos/metabolismo , Cromatografia em Gel/métodos , Cromatografia por Troca Iônica/métodos , Flavobacteriaceae/enzimologia , Polissacarídeo-Liase/metabolismo , Alginatos/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Flavobacteriaceae/genética , Ácidos Hexurônicos/metabolismo , Hidrólise , Polissacarídeo-Liase/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
12.
Ceska Slov Farm ; 68(2): 69-77, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31331176

RESUMO

Currently, the method of external ionic gelation for the preparation of alginate particles is successfully used not only in the field of pharmacy and medicine, but also especially in the field of biotechnology. Therefore, the preparation of alginate particles and their subsequent evaluation using principal component analysis was the key task of our experiment. To optimize this method, we focused on the evaluation of the effect of formulation (the polymer concentration, the hardening solution concentration) and process parameters (the outer diameter of the injection needle) on the properties of the resulting beads (yield, sphericity factor, equivalent diameter and swelling capacity at pH 6). Using multivariate data analysis, the major influence on the resulting properties of the prepared particles was confirmed only in sodium alginate concentration. Obtained results verified the reliable and safe potential of the external ionic gelation for preparation alginate-based particulate dosage forms.


Assuntos
Alginatos/química , Cobre/química , Polímeros , Análise de Componente Principal
13.
Chemphyschem ; 20(16): 2082-2092, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31233266

RESUMO

The studied enzyme-based biocatalytic system mimics NXOR Boolean logic gate, which is a logical operator that corresponds to equality in Boolean algebra. It gives the functional value true (1) if both functional arguments (input signals) have the same logical value (0,0 or 1,1), and false (0) if they are different (0,1 or 1,0). The output signal producing reaction is catalyzed by pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH), which is inhibited at acidic and basic pH values. Two other reactions catalyzed by esterase and urease produce acetic acid and ammonium hydroxide, respectively, shifting solution pH from the optimum pH for PQQ-GDH to acidic and basic values (1,0 and 0,1 input combinations, respectively), thus switching the enzyme activity off (output 0). When the input signals are not applied (0,0 combination) or both applied compensating each other (1,1 combination) the optimum pH is preserved, thus keeping PQQ-GDH running at the high rate (output 1). The biocatalytic cascade mimicking the NXOR gate was characterized optically and electrochemically. In the electrochemical experiments the PQQ-GDH enzyme communicated electronically with a conducting electrode support, thus resulting in the electrocatalytic current when signal combinations 0,0 and 1,1 were applied. The logic gate operation, when it was realized electrochemically, was also extended to the biomolecular release controlled by the gate. The release system included two electrodes, one performing the NXOR gate and another one activated for the release upon electrochemically stimulated alginate hydrogel dissolution. The studied system represents a general approach to the biocatalytic realization of the NXOR logic gate, which can be included in different catalytic cascades mimicking operation of concatenated gates in sophisticated logic circuitries.


Assuntos
Computadores Moleculares , Esterases/química , Glucose Desidrogenase/química , Lógica , Urease/química , Acetatos/química , Alginatos/química , Animais , Canavalia/enzimologia , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Fluoresceína-5-Isotiocianato/química , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Ferro/química , Nanotubos de Carbono/química , Suínos , Ureia/química
14.
Food Chem ; 293: 74-82, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151651

RESUMO

The main object of study is application of whey protein concentrate (WPC) and whey protein hydrolysate (WPH) for probiotic encapsulation. The controlled enzymatic hydrolysis was applied to change technological properties of WPC what leads to obtained different carriers. Probiotic carriers (beads) were made by electrostatic extrusion. Bead properties (mechanical properties, FTIR fingerprint, cell release) and parameters of fermentation were examined. According to cell release, it can be concluded that WPH build less porous matrix with alginate than WPC. Beads with WPH contained more living cells and suffered more changes during fermentation than beads with WPC. Probiotic viability in simulated gastrointestinal conditions (SGIC) is the most critical parameter for probiotic encapsulation. Probiotic encapsulated in protein-alginate beads survived SGIC with more than 96% viable cells, compared to 37.43% for free culture. According to all examined parameters, it can be concluded that WPH builds more suitable carrier for probiotic culture than WPC.


Assuntos
Probióticos , Hidrolisados de Proteína/química , Proteínas do Soro do Leite/química , Alginatos/química , Técnicas de Cultura Celular por Lotes , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Int J Nanomedicine ; 14: 3471-3490, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190805

RESUMO

Background: Zinc-doped hydroxyapatite has been proposed as a graft biomaterial for bone regeneration. However, the effect of zinc on osteoconductivity is still controversial, since the release and resorption of calcium, phosphorus, and zinc in graft-implanted defects have rarely been studied. Methods: Microspheres containing alginate and either non-doped carbonated hydroxyapatite (cHA) or nanocrystalline 3.2 wt% zinc-doped cHA (Zn-cHA) were implanted in critical-sized calvarial defects in Wistar rats for 1, 3, and 6 months. Histological and histomorphometric analyses were performed to evaluate the volume density of newly formed bone, residual biomaterial, and connective tissue formation. Biomaterial degradation was characterized by transmission electron microscopy (TEM) and synchrotron radiation-based X-ray microfluorescence (SR-µXRF), which enabled the elemental mapping of calcium, phosphorus, and zinc on the microsphere-implanted defects at 6 months post-implantation. Results: The bone repair was limited to regions close to the preexistent bone, whereas connective tissue occupied the major part of the defect. Moreover, no significant difference in the amount of new bone formed was found between the two microsphere groups. TEM analysis revealed the degradation of the outer microsphere surface with detachment of the nanoparticle aggregates. According to SR-µXRF, both types of microspheres released high amounts of calcium, phosphorus, and zinc, distributed throughout the defective region. The cHA microsphere surface strongly adsorbed the zinc from organic constituents of the biological fluid, and phosphorus was resorbed more quickly than calcium. In the Zn-cHA group, zinc and calcium had similar release profiles, indicating a stoichiometric dissolution of these elements and non-preferential zinc resorption. Conclusions: The nanometric size of cHA and Zn-cHA was a decisive factor in accelerating the in vivo availability of calcium and zinc. The high calcium and zinc accumulation in the defect, which was not cleared by the biological medium, played a critical role in inhibiting osteoconduction and thus impairing bone repair.


Assuntos
Alginatos/química , Regeneração Óssea , Cálcio/metabolismo , Durapatita/química , Microesferas , Nanopartículas/química , Zinco/química , Zinco/metabolismo , Animais , Materiais Biocompatíveis/química , Disponibilidade Biológica , Regeneração Óssea/efeitos dos fármacos , Carbonatos/química , Morte Celular , Linhagem Celular , Sobrevivência Celular , Feminino , Camundongos , Nanopartículas/ultraestrutura , Ratos Wistar , Crânio/fisiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
16.
Ecotoxicol Environ Saf ; 181: 525-533, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31234067

RESUMO

The mechanism of improving pyrene (PYR)-degrading ability of bacteria CP13 in Layer-by-layer (LBL) assembly chitosan/alginate (CHI/ALG) bio-microcapsules was investigated. Flow cytometry analysis showed that LBL microcapsules could effectively slow down the increasing rate of bacterial cell membrane permeability and the decreasing rate of the membrane potential, so as to reduce the death rate and number of the cells, which could protect the degrading bacteria. The results of Fluorescence spectrum, circular dichroism (CD) spectrum and laser light scattering (LLS) analysis revealed that the other possible mechanism for LBL microcapsules to promote bacterial degradation were following: CHI could enter the secondary structure of the protein of the extracellular polymeric substances (EPS) from CP13 and combined with EPS to generate a stable ground material, which had larger molecular weight (3.76×106 g mol-1) than the original EPS (2.52×106 g mol-1). The combination of CHI and EPS resulted in the decrease of the density of EPS from 1.18 to 0.72 g L-1, suggesting that CHI can loosen the EPS configurations, improving the capture ability of bacteria for PYR as well as the mass transfer of PYR from the extracellular to intracellular, thus eventually promoting the bacteria degrade performance.


Assuntos
Bactérias/metabolismo , Cápsulas/química , Cápsulas/metabolismo , Pirenos/metabolismo , Alginatos/química , Biodegradação Ambiental , Quitosana/química , Matriz Extracelular de Substâncias Poliméricas/química
17.
Carbohydr Polym ; 219: 113-120, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151507

RESUMO

Honey is an ancient natural wound-healing agent and has been reintroduced to modern clinical wound care as it has various bioactivities. In this study, honey was incorporated into an alginate/PVA-based electrospun nanofibrous membrane to develop an efficient wound dressing material. The morphology and chemical composition of the nanofibrous membrane were observed by scanning electron microscopy and characterized via Fourier transform infrared spectroscopy, respectively, demonstrating that honey was successfully introduced to the nanofibers. The nanofibrous membranes with increasing honey content showed enhanced antioxidant activity, suggesting the ability to control the overproduction of reactive oxygen species. Disc diffusion assay and dynamic contact assay proved the antibacterial activity of the honey loaded nanofibers towards Gram-positive bacterium (Staphylococcus aureus) and Gram-negative bacterium (Escherichia coli). The cytotoxicity assay illustrated the non-cytotoxicity and biocompatibility of the nanofibrous membranes. Therefore, the developed honey/alginate/PVA nanofibrous membranes are promising for wound dressings.


Assuntos
Alginatos , Antibacterianos , Antioxidantes , Mel , Membranas/química , Nanofibras , Alginatos/química , Alginatos/uso terapêutico , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Apiterapia , Escherichia coli/efeitos dos fármacos , Humanos , Camundongos , Células NIH 3T3 , Nanofibras/química , Nanofibras/uso terapêutico , Nanofibras/toxicidade , Curativos Oclusivos , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Cicatrização
18.
Chemosphere ; 233: 373-380, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31176900

RESUMO

While surface morphology is the key parameter affecting membrane performance, its exact roles on membrane fouling have not well unveiled. In this study, effects of membrane surface roughness on fouling caused by alginate adhesion were investigated by thermodynamic techniques of the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) approach and density functional theory (DFT). The energy of a single typical alginate chain adhering to rough membrane surface was figured out to be 0.5-3.0 kJ/mol for the first time. Whereas, the related bending energy at typical bending angle was calculated to be over 13.0 kJ/mol based on DFT calculations. The big energy gap suggested that the alginate chain in solution would not change its configuration to fit membrane surface morphology, and tended to directly adhere to membrane surface. The thermodynamic analyses predicted that the direct adhesion pathway was favorable in energy when an alginate chain approaching to rough membrane surface. As a result, as compared to the smooth membrane, rough membrane corresponds to less alginate adhesion and adhesive fouling. Combination of XDLVO and DFT techniques provided not only molecular insights into membrane fouling, but also a new way for fouling research.


Assuntos
Alginatos/química , Incrustação Biológica , Membranas Artificiais , Modelos Teóricos , Aderência Bacteriana , Propriedades de Superfície , Termodinâmica
19.
AAPS PharmSciTech ; 20(6): 241, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31250260

RESUMO

Particulate drug delivery systems (PDDS) have been broadly explored as platforms for delivery of drugs, enzymes, cells, and vaccines for pharmaceutical applications. Studies suggest that microspheres (MS) can stimulate innate immune cells even without a drug payload; however, less is known regarding how they impact host cells in dealing with the bacillary infection. We examined the role of drug-free inhalable alginate microspheres (A-MS) on phagocytosis efficiency and subsequent immune cell activation in Escherichia coli-infected THP-1-derived macrophages. Alginate particles have been widely investigated as carriers for prolonged delivery of bioactive (i.e., drugs, diagnostics, and vaccines). A-MS were fabricated by industry scalable spray-congealing process using divalent cation-induced gelification. E. coli-infected macrophages (multiplicity of infection (MOI 1:10) were treated with drug-free A-MS, where we found a consistent moderate reduction in bacillary viability. Particles were more efficiently and rapidly phagocytized by infected macrophages as compared with normal macrophage cells. Subsequently, A-MS induced markers of M1 macrophage responses and stimulated the processing and secretion of pro-inflammatory cytokines (IL-6, IL-12). It also notably augmented the generation of reactive oxygen species (ROS) and nitric oxide (NO) in infected cells. Results illustrate that, the blank A-MS (without a drug payload) able to moderately check the growth of intracellular E. coli (without significant cytotoxicity) by modulating the M1 inflammatory response by host cells. This "added value" can be utilized in the design and development of therapeutic system with the additional advantage of immune-modulatory activity, in addition to serving as a drug carrier.


Assuntos
Alginatos/farmacologia , Escherichia coli/imunologia , Imunidade Inata/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Microesferas , Alginatos/química , Animais , Citocinas/metabolismo , Humanos , Macrófagos/imunologia , Óxido Nítrico/metabolismo , Fagocitose/efeitos dos fármacos
20.
J Food Sci ; 84(6): 1427-1438, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31070787

RESUMO

Thyme essential oil-loaded microcapsules (TMS) were fabricated using natural polysaccharide chitosan (CS) and sodium alginate (SA) as the shell material via the method of layer-by-layer (LBL) assembly. The accumulated release rates of thyme oil and microcapsules at 4 °C were 42.50% and 10.16%, respectively. After heating at 100 °C for 5 hr, the release rate of the 0, 2, 4, 6 layers assembled microcapsules were 100%, 48.84%, 28.38%, 19.3%, severally. Microcapsules also had good pH sensitivity in the range of 4 to 10. Antimicrobial function studies showed that the microcapsules are more effective than thyme oil for three tested microorganisms. When the temperature rose from 37 °C to 121 °C, the antibacterial zone of thyme oil gradually decreased from 18.5 ± 0.6 mm to 12.3 ± 0.6 mm, although inhibition rate of microcapsules increased from 87.97% to 99.75%. The antibacterial effect of thyme oil declined with the increase of pH, in terms of microcapsules, the efficiency was better under acidic or alkaline conditions. The thyme oil microcapsules can suppress the growth of Staphylococcus aureus in milk and prolong its shelf life. It was determined that this microcapsule could be a potential alternative as a natural antimicrobial agent in food and pharmaceutical industries. PRACTICAL APPLICATION: This work provided release performance and mechanism of layer-by-layer (LBL) thyme oil microcapsule under different conditions, and further studies showed its antibacterial ability to explore how herb essential oils can be potentially applied in food packaging and antibacterial areas.


Assuntos
Óleos Vegetais , Thymus (Planta)/química , Alginatos/química , Animais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Cápsulas/química , Cápsulas/farmacologia , Quitosana/química , Preparações de Ação Retardada , Concentração de Íons de Hidrogênio , Leite/microbiologia , Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Temperatura Ambiente
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