Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 14.159
Filtrar
1.
Int J Nanomedicine ; 15: 6183-6200, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922001

RESUMO

Purpose: Diethylaminoethyl-chitosan (DEAE-CH) is a derivative with excellent potential as a delivery vector for gene therapy applications. The aim of this study is to evaluate its toxicological profile for potential future clinical applications. Methods: An endotoxin-free chitosan (CH) modified with DEAE, folic acid (FA) and polyethylene glycol (PEG) was used to complex small interfering RNA (siRNA) and form nanoparticles (DEAE12-CH-PEG-FA2/siRNA). Based on the guidelines from the International Organization for Standardization (ISO), the American Society for Testing and Materials (ASTM), and the Nanotechnology Characterization Laboratory (NCL), we evaluated the effects of the interaction between these nanoparticles and blood components. In vitro screening assays such as hemolysis, hemagglutination, complement activation, platelet aggregation, coagulation times, cytokine production, and reactive species, such as nitric oxide (NO) and reactive oxygen species (ROS), were performed on erythrocytes, plasma, platelets, peripheral blood mononuclear cells (PBMC) and Raw 264.7 macrophages. Moreover, MTS and LDH assays on Raw 264.7 macrophages, PBMC and MG-63 cells were performed. Results: Our results show that a targeted theoretical plasma concentration (TPC) of DEAE12-CH-PEG-FA2/siRNA nanoparticles falls within the guidelines' thresholds: <1% hemolysis, 2.9% platelet aggregation, no complement activation, and no effect on coagulation times. ROS and NO production levels were comparable to controls. Cytokine secretion (TNF-α, IL-6, IL-4, and IL-10) was not affected by nanoparticles except for IL-1ß and IL-8. Nanoparticles showed a slight agglutination. Cell viability was >70% for TPC in all cell types, although LDH levels were statistically significant in Raw 264.7 macrophages and PBMC after 24 and 48 h of incubation. Conclusion: These DEAE12-CH-PEG-FA2/siRNA nanoparticles fulfill the existing ISO, ASTM and NCL guidelines' threshold criteria, and their low toxicity and blood biocompatibility warrant further investigation for potential clinical applications.


Assuntos
Quitosana/química , Terapia Genética , Nanopartículas/química , Polietilenoglicóis/química , Polímeros/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Ácido Fólico/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Nanopartículas/administração & dosagem , Óxido Nítrico/metabolismo , Células RAW 264.7 , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade
2.
Int J Nanomedicine ; 15: 6433-6449, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922010

RESUMO

Background: Electrospun nanofibers based on Colocasia esculenta tuber (CET) protein are considered as a promising material for wound dressing applications. However, the use of these nanofibers in aqueous conditions has poor stability. The present study was performed to obtain insights into the crosslinked electrospun CET's protein-chitosan (CS)-poly(ethylene oxide) (PEO) nanofibers and to evaluate their potential for wound dressing applications. Methods: The electrospun nanofibers were crosslinked with glutaraldehyde (GA) vapor and heat treatment (HT) to enhance their physicochemical stability. The crosslinked nanofibers were characterized by protein profiles, morphology structures, thermal behavior, mechanical properties, and degradation behavior. Furthermore, the antibacterial properties and cytocompatibility were analyzed by antibacterial assessment and cell proliferation. Results: The protein profiles of the electrospun CET's protein-CS-PEO nanofibers before and after HT crosslinking contained one major bioactive protein with a molecular weight of 14.4 kDa. Scanning electron microscopy images of the crosslinked nanofibers indicated preservation of the structure after immersion in phosphate buffered saline. The crosslinked nanofibers resulted in higher ultimate tensile strength and lower ultimate strain compared to the non-crosslinked nanofibers. GA vapor crosslinking showed higher water stability compared to HT crosslinking. The in vitro antibacterial activity of the crosslinked nanofibers showed a stronger bacteriostatic effect on Staphylococcus aureus than on Escherichia coli. Human skin fibroblast cell proliferation on crosslinked GA vapor and HT nanofibers with 1% (w/v) CS and 2% (w/v) CET's protein demonstrated the highest among all the other crosslinked nanofibers after seven days of cell culture. Cell proliferation and cell morphology results revealed that introducing higher CET's protein concentration on crosslinked nanofibers could increase cell proliferation of the crosslinked nanofibers. Conclusion: These results are promising for the potential use of the crosslinked electrospun CET's protein-CS-PEO nanofibers as bioactive wound dressing materials.


Assuntos
Antibacterianos/farmacologia , Quitosana/química , Colocasia/química , Reagentes para Ligações Cruzadas/química , Nanofibras/química , Proteínas de Plantas/química , Tubérculos/química , Polietilenoglicóis/química , Animais , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Nanofibras/ultraestrutura , Proteínas de Plantas/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Estresse Mecânico , Temperatura
3.
Pharm Res ; 37(10): 195, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32944793

RESUMO

PURPOSE: Design imiquimod-loaded chitosan nanocapsules for transdermal delivery and evaluate the depth of imiquimod transdermal absorption as well as the kinetics of this absorption using Raman Microscopy, an innovative strategy to evaluate transdermal absorption. This nanovehicle included Compritol 888ATO®, a novel excipient for formulating nanosystems whose administration through the skin has not been studied until now. METHODS: Nanocapsules were made by solvent displacement method and their physicochemical properties was measured by DLS and laser-Doppler. For transdermal experiments, newborn pig skin was used. The Raman spectra were obtained using a laser excitation source at 532 nm and a 20/50X oil immersion objective. RESULTS: The designed nanocapsules, presented nanometric size (180 nm), a polydispersity index <0.2 and a zeta potential +17. The controlled release effect of Compritol was observed, with the finding that half of the drug was released at 24 h in comparison with control (p < 0.05). It was verified through Raman microscopy that imiquimod transdermal penetration is dynamic, the nanocapsules take around 50 min to penetrate the stratum corneum and 24 h after transdermal administration, the drug was in the inner layers of the skin. CONCLUSIONS: This study demonstrated the utility of Raman Microscopy to evaluate the drugs transdermal penetration of in the different layers of the skin. Graphical Abstract New imiquimod nanocapsules: evaluation of their skin absorption by Raman Microscopy and effect of the compritol 888ATO® in the imiquimod release profile.


Assuntos
Quitosana/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Ácidos Graxos/farmacocinética , Imiquimode/farmacocinética , Nanocápsulas/administração & dosagem , Pele/metabolismo , Administração Cutânea , Animais , Quitosana/administração & dosagem , Quitosana/química , Ácidos Graxos/administração & dosagem , Ácidos Graxos/química , Imiquimode/administração & dosagem , Imiquimode/química , Nanocápsulas/química , Microscopia Óptica não Linear/métodos , Absorção Cutânea , Suínos
4.
Pharm Res ; 37(10): 196, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32944844

RESUMO

PURPOSE: Hypoxia-inducible factor (HIF) is one of the critical components of the tumor microenvironment that is involved in tumor development. HIF-1α functionally and physically interacts with CDK1, 2, and 5 and stimulates the cell cycle progression and Cyclin-Dependent Kinase (CDK) expression. Therefore, hypoxic tumor microenvironment and CDK overexpression lead to increased cell cycle progression and tumor expansion. Therefore, we decided to suppress cancer cell expansion by blocking HIF-1α and CDK molecules. METHODS: In the present study, we used the carboxylated graphene oxide (CGO) conjugated with trimethyl chitosan (TMC) and hyaluronate (HA) nanoparticles (NPs) loaded with HIF-1α-siRNA and Dinaciclib, the CDK inhibitor, for silencing HIF-1α and blockade of CDKs in CD44-expressing cancer cells and evaluated the impact of combination therapy on proliferation, metastasis, apoptosis, and tumor growth. RESULTS: The results indicated that the manufactured NPs had conceivable physicochemical properties, high cellular uptake, and low toxicity. Moreover, combination therapy of cancer cells using CGO-TMC-HA NPs loaded with HIF-1α siRNA and Dinaciclib (SCH 727965) significantly suppressed the CDKs/HIF-1α and consequently, decreased the proliferation, migration, angiogenesis, and colony formation in tumor cells. CONCLUSIONS: These results indicate the ability of CGO-TMC-HA NPs for dual drug/gene delivery in cancer treatment. Furthermore, the simultaneous inhibition of CDKs/HIF-1α can be considered as a novel anti-cancer treatment strategy; however, further research is needed to confirm this treatment in vivo. Graphical Abstract The suppression of HIF-1α and CDKs inhibits cancer growth. HIF-1α is overexpressed by the cells present in the tumor microenvironment. The hypoxic environment elevates mitochondrial ROS production and increases p38 MAP kinase, JAK/STAT, ERK, JNK, and Akt/PI3K signaling, resulting in cyclin accumulation and aberrant cell cycle progression. Furthermore, the overexpression of HIF-1α/CDK results in increased expression of genes such as BCL2, Bcl-xl, Ki-67, TGFß, VEGF, FGF, MMP2, MMP9, and, HIF-1α and consequently raise the survival, proliferation, angiogenesis, metastasis, and invasion of tumor cells. In conclusion, HIF-1α-siRNA/Dinaciclib-loaded CGO-TMC-HA NPs can inhibit the tumor expansion by blockage of CDKs and HIF-1α (JAK: Janus kinase, STAT: Signal transducer and activator of transcription, MAPK: mitogen-activated protein kinase, ERK: extracellular signal-regulated kinase, JNK: c-Jun N-terminal kinase, PI3K: phosphatidylinositol 3-kinase).


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neoplasias Experimentais/terapia , Compostos de Piridínio/administração & dosagem , RNA Interferente Pequeno/administração & dosagem , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Quitosana/química , Grafite/química , Ácido Hialurônico/química , Camundongos , Nanopartículas/química , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Compostos de Piridínio/química , Compostos de Piridínio/farmacocinética , RNA Interferente Pequeno/química , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacocinética
5.
Int J Nanomedicine ; 15: 4877-4898, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32753869

RESUMO

Background: Although dynamics and uses of modified nanoparticles (NPs) as orally administered macromolecular drugs have been researched for many years, measures of molecule stability and aspects related to important transport-related mechanisms which have been assessed in vivo remain as relatively under characterized. Thus, our aim was to develop a novel type of oral-based delivery system for insulin and to overcome barriers to studying the stability, transport mechanisms, and efficacy in vivo of the delivery system. Methods: NPs we developed and tested were composed of insulin (INS), dicyandiamide-modified chitosan (DCDA-CS), cell-penetrating octaarginine (r8), and hydrophilic hyaluronic acid (HA) and were physically constructed by electrostatic self-assembly techniques. Results: Compared to free-insulin, levels of HA-DCDA-CS-r8-INS NPs were retained at more desirable measures of biological activity in our study. Further, our assessments of the mechanisms for NPs suggested that there were high measures of cellular uptake that mainly achieved through active transport via lipid rafts and the macropinocytosis pathway. Furthermore, investigations of NPs indicated their involvement in caveolae-mediated transport and in the DCDA-CS-mediated paracellular pathway, which contributed to increasing the efficiency of sequential transportation from the apical to basolateral areas. Accordingly, high efficiency of absorption of NPs in situ for intestinal loop models was realized. Consequently, there was a strong induction of a hypoglycemic effect in diabetic rats of NPs via orally based administrations when compared with measures related to free insulin. Conclusion: Overall, the dynamics underlying and influenced by HA-DCDA-CS-r8-INS may hold great promise for stability of insulin and could help overcome interference by the epithelial barrier, and thus showing a great potential to improve the efficacy of orally related treatments.


Assuntos
Quitosana/química , Ácido Hialurônico/química , Insulina/administração & dosagem , Nanopartículas Multifuncionais/química , Nanopartículas/química , Administração Oral , Animais , Transporte Biológico/efeitos dos fármacos , Células CACO-2 , Morte Celular/efeitos dos fármacos , Quitosana/síntese química , Diabetes Mellitus Experimental/tratamento farmacológico , Impedância Elétrica , Endocitose/efeitos dos fármacos , Guanidinas/síntese química , Guanidinas/química , Humanos , Ácido Hialurônico/síntese química , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/farmacologia , Insulina/uso terapêutico , Absorção Intestinal/efeitos dos fármacos , Masculino , Muco/metabolismo , Nanopartículas/ultraestrutura , Ratos , Solubilidade , Suínos
6.
Int J Nanomedicine ; 15: 5005-5016, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764932

RESUMO

Background and Aim: With the wide applications of chitosan and gold nanoparticles in drug delivery and many consumer products, there is limited available information about their effects on drug-metabolizing enzymes (DMEs). Changes in DMEs could result in serious drug interactions. Therefore, this study aimed to investigate the effects of exposure to chitosan or gold nanoparticles on hepatic Phase I and II DMEs, liver function and integrity, oxidative damage and liver architecture in male rats. Methods: Animals were divided into three equal groups: a control group, a group treated with chitosan nanoparticles (200 mg/kg, 50±5 nm) and a group treated with gold nanoparticles (4 mg/kg, 15±5 nm). Rats were orally administered their respective doses daily for 10 days. Results: Both chitosan and gold nanoparticles decreased the body weights by more than 10%. Gold nanoparticles reduced the activities of antioxidants (superoxide dismutase and catalase), and reduced glutathione level and elevated the malondialdehyde level in the liver. Gold nanoparticles caused significant reductions in CYP1A1, CYP2E1, quinone oxidoreductase1, and glutathione S-transferase and elevated CYP2D6 and N-acetyl transferase2. Chitosan elevated CYP2E1 and CYP2D6 and reduced UDP-glucuronosyltransferase 1A1. Both nanoparticles disturbed the architecture of the liver, but the deleterious effects after gold nanoparticles treatment were more prominent. Conclusion: Taken together, gold nanoparticles severely perturbed the DMEs and would result in serious interactions with many drugs, herbs, and foods.


Assuntos
Antioxidantes/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Inativação Metabólica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Nanopartículas Metálicas/efeitos adversos , Animais , Catalase/genética , Catalase/metabolismo , Quitosana/química , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP2E1/metabolismo , Interações Medicamentosas , Glucuronosiltransferase/genética , Glucuronosiltransferase/metabolismo , Glutationa/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Ouro/química , Ouro/farmacocinética , Fígado/metabolismo , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Nanopartículas Metálicas/química , Ratos Wistar , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
7.
Int J Nanomedicine ; 15: 5629-5643, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801706

RESUMO

Purpose: Lecithin/chitosan nanoparticles have shown great promise in the transdermal delivery of therapeutic agents. Baicalein, a natural bioactive flavonoid, possesses multiple biological activities against dermatosis. However, its topical application is limited due to its inherently poor hydrophilicity and lipophilicity. In this study, the baicalein-phospholipid complex was prepared to enhance the lipophilicity of baicalein and then lecithin/chitosan nanoparticles loaded with the baicalein-phospholipid complex were developed to improve the transdermal retention and permeability of baicalein. Methods: Lecithin/chitosan nanoparticles were prepared by the solvent-injection method and characterized in terms of particle size distribution, zeta potential, and morphology. The in vitro release, the ex vivo and in vivo permeation studies, and safety evaluation of lecithin/chitosan nanoparticles were performed to evaluate the effectiveness in enhancing transdermal retention and permeability of baicalein. Results: The lecithin/chitosan nanoparticles obtained by the self-assembled interaction of chitosan and lecithin not only efficiently encapsulated the drug with high entrapment efficiency (84.5%) but also provided sustained release of baicalein without initial burst release. Importantly, analysis of the permeation profile ex vivo and in vivo demonstrated that lecithin/chitosan nanoparticles prolonged the retention of baicalein in the skin and efficiently penetrated the barrier of stratum corneum without displaying skin irritation. Conclusion: These results indicate the potential of drug-phospholipid complexes in enhancing the entrapment efficiency and self-assembled lecithin/chitosan nanoparticles based on phospholipid complexes in the design of a rational transdermal delivery platform to improve the efficiency of transdermal therapy by enhancing its percutaneous retention and penetration in the skin.


Assuntos
Flavanonas/administração & dosagem , Nanopartículas/administração & dosagem , Fosfolipídeos/química , Administração Cutânea , Animais , Quitosana/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Flavanonas/farmacocinética , Interações Hidrofóbicas e Hidrofílicas , Lecitinas/química , Masculino , Nanopartículas/efeitos adversos , Nanopartículas/química , Permeabilidade , Ratos Sprague-Dawley , Pele/efeitos dos fármacos , Pele/patologia , Absorção Cutânea/efeitos dos fármacos , Testes de Irritação da Pele
8.
Int J Food Microbiol ; 331: 108786, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32659617

RESUMO

Sweet orange essential oil is obtained from the peels of Citrus sinensis (CSEO) by cold pressing, and used as a valuable product by the food industry. Nanoencapsulation is known as a valid strategy to improve chemical stability, organoleptic properties, and delivery of EO-based products. In the present study we encapsulated CSEO using chitosan nanoemulsions (cn) as nanocarrier, and evaluated its antimicrobial activity in combination with mild heat, as well as its sensorial acceptability in orange and apple juices. CSEO composition was analyzed by GC-MS, and 19 components were identified, with limonene as the predominant constituent (95.1%). cn-CSEO was prepared under low shear conditions and characterized according to droplet size (<60 nm) and polydispersity index (<0.260 nm). Nanoemulsions were stable for at least 3 months at 4 ± 2 °C. cn-CSEO were compared with suspensions of CSEO (s-CSEO) (0.2 µL of CSEO/mL) in terms of antibacterial activity in combination with mild heat (52 °C) against Escherichia coli O157:H7 Sakai. cn-CSEO displayed a greater bactericidal activity than s-CSEO at pH 7.0 and pH 4.0. The validation in fruit juices showed an improved bactericidal effect of cn-CSEO in comparison with s-CSEO when combined with mild heat in apple juice, but not in orange juice. In both juices, the combination of CSEO and mild heat exerted synergistic lethal effects, reducing the treatment time to cause the inactivation of up to 5 Log10 cycles of E. coli O157:H7 Sakai cells. Finally, the sensory characteristics of both juices were acceptable either when using s-CSEO or CSEO nanoemulsified with chitosan. Therefore, as a promising carrier for lipophilic substances, the encapsulation of EOs with chitosan nanoemulsions might represent an advantageous alternative when combined with mild heat to preserve fruit juices.


Assuntos
Quitosana/química , Emulsões/farmacologia , Conservação de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Bebidas/microbiologia , Quitosana/farmacologia , Citrus sinensis/química , Contagem de Colônia Microbiana , Emulsões/química , Escherichia coli O157/efeitos dos fármacos , Frutas/química , Temperatura Alta , Malus/microbiologia
9.
Int J Food Microbiol ; 330: 108766, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32659522

RESUMO

The aim of the study was to explore the antifungal and aflatoxin B1 inhibitory efficacy of nanoencapsulated antifungal formulation. Mixture design response surface methodology (RSM) was utilized to design the antifungal formulation (SBC 4:1:1) based on the combination of chemically characterized Ocimum sanctum (S), O. basilicum (B), and O. canum (C) against Aspergillus flavus. The SBC was incorporated inside the chitosan nanomatrix (Ne-SBC) using an ultrasonic probe (40 kHz) and interactions were confirmed by SEM, FTIR and XRD analysis. The results showed that the Ne-SBC possessed enhanced antifungal and aflatoxin B1 inhibitory effect over the free form of SBC. The biochemical and in silico results indicate that the antifungal and aflatoxin B1 inhibitory effect was related to perturbance in the plasma membrane function (ergosterol biosynthesis and membrane cation) mitochondrial membrane potential, C-sources utilization, antioxidant defense system, and the targeted gene products Erg 28, cytochrome c oxidase subunit Va, and Nor-1. In-situ observation revealed that Ne-SBC effectively protects the Avena sativa seeds from A. flavus and AFB1 contamination and preserves its sensory profile. The findings suggest that the fabrication of SBC inside the chitosan nano-matrix has promising use in the food industries as an antifungal agent.


Assuntos
Aflatoxina B1/antagonistas & inibidores , Antifúngicos/farmacologia , Microbiologia de Alimentos , Ocimum/química , Óleos Voláteis/farmacologia , Aflatoxina B1/metabolismo , Antifúngicos/química , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/metabolismo , Quitosana/química , Quitosana/farmacologia , Composição de Medicamentos , Ocimum/classificação , Óleos Voláteis/química , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Sementes/microbiologia
10.
PLoS One ; 15(7): e0236371, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706802

RESUMO

We present a simple but accurate algorithm to calculate the flow and shear rate profile of shear thinning fluids, as typically used in biofabrication applications, with an arbitrary viscosity-shear rate relationship in a cylindrical nozzle. By interpolating the viscosity with a set of power-law functions, we obtain a mathematically exact piecewise solution to the incompressible Navier-Stokes equation. The algorithm is validated with known solutions for a simplified Carreau-Yasuda fluid, full numerical simulations for a realistic chitosan hydrogel as well as experimental velocity profiles of alginate and chitosan solutions in a microfluidic channel. We implement the algorithm in an easy-to-use Python tool, included as Supplementary Material, to calculate the velocity and shear rate profile during the printing process, depending on the shear thinning behavior of the bioink and printing parameters such as pressure and nozzle size. We confirm that the shear stress varies in an exactly linear fashion, starting from zero at the nozzle center to the maximum shear stress at the wall, independent of the shear thinning properties of the bioink. Finally, we demonstrate how our method can be inverted to obtain rheological bioink parameters in-situ directly before or even during printing from experimentally measured flow rate versus pressure data.


Assuntos
Alginatos/química , Quitosana/química , Hidrogéis/química , Agulhas , Impressão Tridimensional/instrumentação , Algoritmos , Hidrodinâmica , Microfluídica , Resistência ao Cisalhamento , Viscosidade
11.
Food Chem ; 332: 127375, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32622189

RESUMO

Biopolymer films based on chitosan/potato protein/linseed oil/ZnO NPs were developed to maintain the storage quality of raw meat. Results indicated that the incorporation of ZnO NPs could effectively improve the transparency and tensile strength of the films, while addition of linseed oil could make the composite film maintain good elastic property. Films blended with chitosan/potato protein/linseed oil/ZnO NPs (Fcpzl) exhibited an excellent moisture barrier capability. SEM showed that ZnO NPs could harmoniously exist in various polymers matrix. FTIR analysis demonstrated that different components were bound together by intramolecular and intermolecular interactions, among which hydrogen bonds were the main force. Raw meat samples were wrapped with different films to evaluate the preservative effect during 4 °C storage. Results indicated that Fcpzl possessed best protective effect of raw meat with excellent acceptable sensory properties during 7 days storage, which could reduce the speed of increasing pH and total bacterial counts.


Assuntos
Quitosana/química , Embalagem de Alimentos/métodos , Armazenamento de Alimentos/métodos , Óleo de Semente do Linho/química , Carne , Proteínas de Plantas/química , Óxido de Zinco/química , Qualidade dos Alimentos , Carne/microbiologia , Solanum tuberosum/química , Resistência à Tração
12.
Int J Nanomedicine ; 15: 4717-4737, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32636627

RESUMO

Purpose: The present study was designed to study the gentamycin (GTM)-loaded stimulus-responsive chitosan nanoparticles to treat bacterial conjunctivitis. Methods: GTM-loaded chitosan nanoparticles (GTM-CHNPs) were prepared by ionotropic gelation method and further optimized by 3-factor and 3-level Box-Behnken design. Chitosan (A), sodium tripolyphosphate (B), and stirring speed (C) were selected as independent variables. Their effects were observed on particle size (PS as Y1), entrapment efficiency (EE as Y2), and loading capacity (LC as Y3). Results: The optimized formulation showed the particle size, entrapment efficiency, and loading capacity of 135.2±3.24 nm, 60.18±1.65%, and 34.19±1.17%, respectively. The optimized gentamycin-loaded chitosan nanoparticle (GTM-CHNPopt) was further converted to the stimulus-responsive sol-gel system (using pH-sensitive carbopol 974P). GTM-CHNPopt sol-gel (NSG5) exhibited good gelling strength and sustained release (58.99±1.28% in 12h). The corneal hydration and histopathology of excised goat cornea revealed safe to the cornea. It also exhibited significant (p<0.05) higher ZOI than the marketed eye drop. Conclusion: The finding suggests that GTM-CHNP-based sol-gel is suitable for ocular delivery to enhance the corneal contact time and improved patient compliance.


Assuntos
Antibacterianos/administração & dosagem , Gentamicinas/administração & dosagem , Gentamicinas/farmacologia , Hidrogéis/administração & dosagem , Nanopartículas/química , Administração Oftálmica , Animais , Antibacterianos/farmacologia , Quitosana/química , Córnea/efeitos dos fármacos , Portadores de Fármacos , Liberação Controlada de Fármacos , Hidrogéis/química , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Polifosfatos/química , Reologia
13.
Int J Nanomedicine ; 15: 4471-4481, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606689

RESUMO

Background: Ineffective integration has been recognized as one of the major causes of early orthopedic failure of titanium-based implants. One strategy to address this problem is to develop modified titanium surfaces that promote osteoblast differentiation. This study explored titanium surfaces modified with TiO2 nanotubes (TiO2 NTs) capable of localized drug delivery into bone and enhanced osteoblast cell differentiation. Materials and Methods: Briefly, TiO2 NTs were subjected to anodic oxidation and loaded with Metformin, a widely used diabetes drug. To create surfaces with sustainable drug-eluting characteristics, TiO2 NTs were spin coated with a thin layer of chitosan. The surfaces were characterized via scanning electron microscopy, atomic force microscopy, and contact angle measurements. The surfaces were then exposed to mesenchymal bone marrow stem cells (MSCs) to evaluate cell adhesion, growth, differentiation, and morphology on the modified surfaces. Results: A noticeable increase in drug release time (3 days vs 20 days) and a decrease in burst release characteristics (85% to 7%) was observed in coated samples as compared to uncoated samples, respectively. Chitosan-coated TiO2 NTs exhibited a considerable enhancement in cell adhesion, proliferation, and genetic expression of type I collagen, and alkaline phosphatase activity as compared to uncoated TiO2 NTs. Conclusion: TiO2 NT surfaces with a chitosan coating are capable of delivering Metformin to a bone site over a sustained period of time with the potential to enhance MSCs cell attachment, proliferation, and differentiation.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Quitosana/química , Liberação Controlada de Fármacos , Metformina/farmacologia , Nanotubos/química , Osteoblastos/citologia , Titânio/química , Fosfatase Alcalina/metabolismo , Animais , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Nanotubos/ultraestrutura , Osteoblastos/efeitos dos fármacos , Osteoblastos/ultraestrutura , Osteogênese/efeitos dos fármacos , Ratos Wistar , Molhabilidade
14.
Food Chem ; 333: 127493, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32659659

RESUMO

The effects of the addition of salt ions and molecular weights (Mw) of CH on Mesona chinensis polysaccharide (MCP)-chitosan (CH) hydrogel were investigated. Result indicated both low concentration of monovalent salt ions (Na+ and K+), divalent cations (Ca2+) and oxoanions (SO42-) could promote the gel properties of MCP-CH hydrogel. The Mw of CH has huge impact on the formation and properties of hydrogel. Combining the relationship between rheology and structural, monovalent salt ions such as Na+ and K+ affect gel formation and its properties by influencing electrostatic interaction and chain conformation. Both divalent cations (Ca2+) and oxoanions (SO42-) facilitated the formation of gel networks via electrostatic interaction, coordination bonds and hydrogen bonds. Moreover, Mw of CH influenced formation and texture of MCP-CH hydrogel via affecting the conformation of CH molecular chain. These findings will provide a few theoretical bases to understand the formation mechanism of MCP-CH hydrogel.


Assuntos
Quitosana/química , Hidrogéis/química , Lamiaceae/química , Extratos Vegetais/química , Polieletrólitos/química , Sais/química , Ânions/química , Cálcio/química , Hidrogéis/síntese química , Peso Molecular , Polissacarídeos/química , Potássio/química , Reologia , Sódio/química
15.
Food Chem ; 333: 127524, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679418

RESUMO

Semicarbazide (SEM) is a protein-bound nitrofurazone metabolite that is detrimental to human health. Therefore, to ensure food safety, it is necessary to detect SEM in food samples. To this end, we developed a novel electrochemical sensor to detect SEM by using a molecularly imprinted polymer (MIP) as the recognition element. Computer-aided molecular modelling was performed to guide the synthesis of the MIP, and subsequently, MIP/carboxylated single-walled carbon-nanotubes/chitosan (MIP/SWNTs-COOH/CS) was prepared as the sensing platform to develop the electrochemical sensor. The linear range of the sensor was 0.04-7.6 ng mL-1, with a detection limit of 0.025 ng mL-1. The sensor was successfully applied to detect SEM in four different real samples, with recoveries ranging from 83.16% to 93.40%. The results indicated that the fabricated electrochemical sensor can be widely applied to detect SEM in the environment and in agri-food products.


Assuntos
Quitosana/química , Técnicas Eletroquímicas/métodos , Impressão Molecular , Nanotubos de Carbono/química , Semicarbazidas/análise , Eletrodos , Mel/análise , Humanos , Limite de Detecção , Carne/análise , Polímeros/química , Reprodutibilidade dos Testes , Alimentos Marinhos/análise
16.
AAPS PharmSciTech ; 21(5): 173, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32548717

RESUMO

Innovative strategies for periodontal regeneration have been the focus of research clusters across the globe for decades. In order to overcome the drawbacks of currently available options, investigators have suggested a novel concept of functionally graded membrane (FGM) templates with different structural and morphological gradients. Chitosan (CH) has been used in the past for similar purpose. However, the composite formulation of composite and tetracycline when cross-linked with glutaraldehyde have received little attention. Therefore, the purpose of the study was to investigate the drug loading and release characteristics of novel freeze gelated chitosan templates at different percentages of glutaraldehyde. These were cross-linked with 0.1 and 1% glutaraldehyde and loaded with doxycycline hyclate. The electron micrographs depicted porous morphology of neat templates. After cross-linking, these templates showed compressed ultrastructures. Computerized tomography analysis showed that the templates had 88 to 92% porosity with average pore diameter decreased from 78 to 44.9 µm with increasing concentration. Fourier transform infrared spectroscopy showed alterations in the glycosidic segment of chitosan fingerprint region which after drug loading showed a dominant doxycycline spectral composite profile. Interestingly, swelling profile was not affected by cross-linking either at 0.1 and 1% glutaraldehyde and template showed a swelling ratio of 80%, which gained equilibrium after 15 min. The drug release pattern also showed a 40 µg/mL of release after 24 h. These doxycycline-loaded templates show their tendency to be used in a functionally graded membrane facing the defect site.


Assuntos
Materiais Biocompatíveis/química , Quitosana/química , Reagentes para Ligações Cruzadas/química , Congelamento , Regeneração Tecidual Guiada Periodontal/métodos , Materiais Biocompatíveis/farmacocinética , Quitosana/farmacocinética , Reagentes para Ligações Cruzadas/farmacocinética , Liberação Controlada de Fármacos , Géis , Glutaral/química , Glutaral/farmacocinética , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
17.
AAPS PharmSciTech ; 21(5): 167, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32504176

RESUMO

Ciprofloxacin is a commonly used antibiotic for treatment of bacterial conjunctivitis. The conventional eye drop dosage form is the widely used mode of treatment, but it has low corneal residence time. This drawback can be overcome by developing a bioadhesive noisome system (chitosan-coated) for enhanced corneal residence time. The niosomes were prepared by thin-film hydration technique and optimized by using Box-Behnken statistical design software. Cholesterol (A), Span 60 (B), and sonication time (C) were selected as independent variables, whereas vesicle size (Y1 in nm), entrapment efficiency (Y2 in %), and drug release (Y3 in %) were chosen as dependent variables. The vesicle size, entrapment efficiency, and drug release of optimized CIP niosomes (CIP-NSMopt) were found to be 180.34 ± 5.13 nm, 78.32 ± 4.49%, and 82.87 ± 4.01% (in 12 h), respectively. Further CIP-NSMopt was coated with different chitosan concentrations (0.1 to 0.3%) to enhance mucoadhesion. Finally, optimized chitosan-coated niosomes (chitosomes; CIP-CHTopt) showed a vesicle size of 210.65 ± 2.76 nm, zeta potential of - 35.17 ± 2.25Mv, and PDI of 0.221. CIP-CHTopt exhibited sustained release profile (75.31% in 12 h) with the Korsmeyer-Peppas kinetic model (R2 = 0.980). The permeation study showed 1.79-fold enhancements in corneal permeation compared with marketed CIP eye drop. The hen's egg chorioallantoic membrane (HET-CAM) study showed 0 scores (no irritation), and it was further confirmed by corneal hydration and histopathology study. The antimicrobial study exhibited a significant high zone (P < 0.05) of inhibition against tested organism. Our findings demonstrated that chitosan-coated niosomes are a promising drug carrier to enhance corneal contact time and treatment of bacterial conjunctivitis.


Assuntos
Antibacterianos/química , Quitosana/química , Membrana Corioalantoide/efeitos dos fármacos , Ciprofloxacino/química , Soluções Oftálmicas/química , Animais , Galinhas , Ciprofloxacino/farmacologia , Ciprofloxacino/toxicidade , Portadores de Fármacos , Composição de Medicamentos , Lipossomos/química
18.
Food Chem ; 330: 127239, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32540522

RESUMO

Crabapple (Malus prunifolia Willd. Borkh) is a kind of wild apples with many health benefits. However, the utilization of crabapple fruit remains scarce, due to the poor stability of C3G. In this study, C3G loaded nanoparticles were established by chitosan (CS), chitosan oligosaccharides (CSO), and carboxymethyl chitosan (CMC) united with ionic crosslinking agent γ-Polyglutamic acid (PGA) or calcium chloride (CaCl2) to improve the stability of C3G. Results showed that C3G-loaded nanoparticles were exhibited nearly spherical with homogeneous morphology. Particularly, C3G-CMC-CaCl2 nanoparticles exhibited the highest encapsulation efficiency (53.88%) and loading efficiency (5.11%) with preferable particle size (180 nm), good stability (-19 mV) and blood compatibility. C3G-CMC-CaCl2 nanoparticles also revealed the highest releasing ratio (~75%) at pH 5.3 with stability. Present study established the chemical and cell biological basis for further application of C3G-loaded nanoparticles in nutraceutical and functional food fields, extending the application of crabapple in food processing with bioactive enhancement.


Assuntos
Antocianinas/química , Glucosídeos/química , Nanopartículas/química , Quitosana/análogos & derivados , Quitosana/química , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Tamanho da Partícula
19.
Food Chem ; 329: 126989, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32502742

RESUMO

In this study, a polyethylene (PE) film coated with chitosan (CS) and gallic acid (GA) was prepared using plasma modification technology and applied for the preservation of tilapia fillets. Based on the analysis of surface morphology and surface functional groups, it was shown that plasma modification allowed CS and GA coating on PE. And GACS/PE demonstrated better antioxidant ability than CS/PE and GA/PE individually. The results of the tilapia freshness test showed that the total plate count showed that GACS/PE can inhibit 1.52 log CFU/g and delay the production of volatile basic nitrogen below 15 mg/100 g after 14 d of storage. Moreover, GA/PE (0.26 mg MDA/kg) and GACS/PE (0.24 mg MDA/kg) showed better thiobarbituric acid inhibitiry effect than control (0.30 mg MDA/kg) on day 14. These results indicate that these packaging films are efficient in extending the shelf life of tilapia fillets.


Assuntos
Quitosana/química , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Ácido Gálico/química , Polietileno/química , Tilápia , Animais
20.
J Chromatogr A ; 1623: 461198, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505287

RESUMO

Microcystins (MCs) and nodularin (NOD) are tumor promoters produced by cyanobacteria and present in surface water. In this work, a novel mesoporous metal-organic framework-5@chitosan (MOF-5@CS) material was synthesized and applied for the enrichment of MCs and NOD in water and fish samples. The mesoporous MOF-5@CS material was firstly synthesized via a one-step hydrothermal method, and the chitosan was combined with MOF-5 via chemical bonding assembly. As a new adsorbent, the as-synthesized material was found having a large specific surface area and good thermal stability. Under the optimized conditions, MCs and NOD were enriched by the MOF-5@CS material and detected by ultra-performance liquid chromatography-tandem mass spectrometry. The limit of detection of the new method for MCs and NOD were in the range of 0.0018-0.077 ng/mL. The value of relative standard deviation for repeatability were 2.69-6.30%, and the recovery of the analytes ranged from 84.36% to 118.51%. Compared with other reported method for MCs and NOD detection in complex matrices, better adsorption performance for MCs and NOD were obtained by our new method, and the sensitivity of MCs-RR and NOD were improved nearly 20 times and 30 times, respectively.


Assuntos
Quitosana/química , Cromatografia Líquida de Alta Pressão/métodos , Estruturas Metalorgânicas/química , Microcistinas/análise , Peptídeos Cíclicos/análise , Espectrometria de Massas em Tandem/métodos , Adsorção , Microcistinas/química , Peptídeos Cíclicos/química , Padrões de Referência , Reprodutibilidade dos Testes , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA