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1.
Antioxidants (Basel) ; 12(10)2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37891945

RESUMO

The bacterium Helicobacter pylori (H. pylori) represents a major risk factor associated with the development of gastric cancer. The anti-oxidant curcumin has been ascribed many benefits to human health, including bactericidal effects. However, these effects are poorly reproducible because the molecule is extremely unstable and water insoluble. Here we solubilized curcumin as either nanoemulsions or chitosan nanocapsules and tested the effects on H. pylori. The nanoemulsions were on average 200 nm in diameter with a PdI ≤ 0.16 and a negative zeta potential (-54 mV), while the nanocapsules were 305 nm in diameter with a PdI ≤ 0.29 and a positive zeta potential (+68 mV). Nanocapsules were safer than nanoemulsions when testing effects on the viability of GES-1 gastric cells. Also, nanocapsules were more efficient than nanoemulsions at inhibiting H. pylori growth (minimal inhibitory concentration: 50 and 75 µM, respectively), whereby chitosan contributed to this activity. Importantly, both formulations effectively diminished H. pylori's adherence to and internalization by GES-1 cells, as well as biofilm formation. In summary, the demonstrated activity of the curcumin nanoformulations described here against H. pylori posit them as having great potential to treat or complement other therapies currently in use against H. pylori infection.

2.
Polymers (Basel) ; 16(1)2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38201804

RESUMO

Iron deficiency anemia (IDA) presents a global health challenge, impacting crucial development stages in humans and other mammals. Pigs, having physiological and metabolic similarities with humans, are a valuable model for studying and preventing anemia. Commonly, a commercial iron dextran formulation (CIDF) with iron dextran particles (IDPs) is intramuscularly administered for IDA prevention in pigs, yet its rapid metabolism limits preventive efficacy. This study aimed to develop and evaluate chitosan thermosensitive hydrogels (CTHs) as a novel parenteral iron supplementation strategy, promoting IDPs' prolonged release and mitigating their rapid metabolism. These CTHs, loaded with IDPs (0.1, 0.2, and 0.4 g of theoretical iron/g of chitosan), were characterized for IM iron supplementation. Exhibiting thermosensitivity, these formulations facilitated IM injection at ~4 °C, and its significant increasing viscosity at 25-37 °C physically entrapped the IDPs within the chitosan's hydrophobic gel without chemical bonding. In vitro studies showed CIDF released all the iron in 6 h, while CTH0.4 had a 40% release in 72 h, mainly through Fickian diffusion. The controlled release of CTHs was attributed to the physical entrapment of IDPs within the CTHs' gel, which acts as a diffusion barrier. CTHs would be an effective hydrogel prototype for prolonged-release parenteral iron supplementation.

3.
Food Funct ; 13(3): 1370-1379, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35044402

RESUMO

Among vegetable oils, chia oil has been gaining interest in recent years due to its high linolenic acid content (ALA, 18:3 ω3). The aim of this work was to study the influence of the particle size of encapsulated purified chia oil (PCO) on the encapsulation efficiency and PCO release during in vitro digestion. PCO micro- and nano-sized particles with sodium alginate (SA) as an encapsulating agent (ME-PCO-SA and NE-PCO-SA) were designed by micro and nano spray-drying, respectively, applying a central composite plus star point experimental design. NE-PCO-SA showed a smaller particle size and higher encapsulation efficiency of PCO than ME-PCO-SA (0.16 µm vs. 3.5 µm; 98.1% vs. 92.0%). Emulsions (NE-PCO and ME-PCO) and particles (NE-PCO-SA and ME-PCO-SA) were subjected to in vitro static gastrointestinal digestion. ME-PCO and NE-PCO showed sustained oil release throughout the three phases of digestion (oral, gastric and intestinal phases), whereas the PCO release from ME-PCO-SA and NE-PCO-SA occurred mainly in the intestinal phase, showing the suitability of sodium alginate as an intestine-site release polymer. Nano-sized particles showed a significantly higher PCO release after in vitro digestion (NE-PCO-SA, 78.4%) than micro-sized particles (ME-PCO-SA, 69.8%), and also higher bioaccessibility of individual free fatty acids, such as C18:3 ω-3 (NE-PCO-SA, 23.6%; ME-PCO-SA, 7.9%), due to their greater surface area. However, when ME-PCO-SA and NE-PCO-SA were incorporated into yogurt, the PCO release from both particle systems after the digestion of the matrix was similar (NE-PCO-SA, 58.8%; ME-PCO-SA-Y, 61.8%), possibly because the calcium ions contained in the yogurt induced partial ionic gelation of SA, impairing the PCO release. Sodium alginate spray-dried micro and nanoparticles showed great potential for vehiculation of omega-3 rich oils in the design of functional foods.


Assuntos
Digestão/efeitos dos fármacos , Óleos de Plantas/farmacologia , Salvia hispanica , Alginatos/química , Alimento Funcional , Trato Gastrointestinal/efeitos dos fármacos , Humanos , Nanopartículas , Óleos de Plantas/química
4.
Int J Mol Sci ; 22(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34445078

RESUMO

The Smoothened (SMO) receptor is the most druggable target in the Hedgehog (HH) pathway for anticancer compounds. However, SMO antagonists such as vismodegib rapidly develop drug resistance. In this study, new SMO antagonists having the versatile purine ring as a scaffold were designed, synthesised, and biologically tested to provide an insight to their mechanism of action. Compound 4s was the most active and the best inhibitor of cell growth and selectively cytotoxic to cancer cells. 4s induced cell cycle arrest, apoptosis, a reduction in colony formation and downregulation of PTCH and GLI1 expression. BODIPY-cyclopamine displacement assays confirmed 4s is a SMO antagonist. In vivo, 4s strongly inhibited tumour relapse and metastasis of melanoma cells in mice. In vitro, 4s was more efficient than vismodegib to induce apoptosis in human cancer cells and that might be attributed to its dual ability to function as a SMO antagonist and apoptosis inducer.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Purinas/farmacologia , Receptor Smoothened/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células HT29 , Proteínas Hedgehog/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Neoplasias/metabolismo , Purinas/química , Purinas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Receptor Smoothened/metabolismo
5.
J Control Release ; 331: 443-459, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33220325

RESUMO

Multiple sclerosis (MS) is an autoimmune disease affecting the central nervous system (CNS). Interferon (IFN)-ß constitutes one of the first-line therapies to treat MS, but has limited efficacy due to the injectable systemic administration, short half-life, and limited CNS access. To address these limitations, we developed IFN-ß-loaded chitosan/sulfobutylether-ß-cyclodextrin nanoparticles (IFN-ß-NPs) for delivery of IFN-ß into the CNS via the intranasal (i.n.) route. The nanoparticles (NPs) (≈200 nm, polydispersity ≈0.1, and zeta potential ≈20 mV) were prepared by mixing two aqueous solutions and associated human or murine IFN-ß with high efficiency (90%). Functional in vitro assays showed that IFN-ß-NPs were safe and that IFN-ß was steadily released while retaining biological activity. Biodistribution analysis showed an early and high fluorescence in the brain after nasal administration of fluorescent probe-loaded NPs. Remarkably, mice developing experimental autoimmune encephalomyelitis (EAE), an experimental model of MS, exhibited a significant improvement of clinical symptoms in response to intranasal IFN-ß-NPs (inIFN-ß-NPs), whereas a similar dose of intranasal or systemic free IFN-ß had no effect. Importantly, inIFN-ß-NPs treatment was equally effective despite a reduction of 78% in the total amount of weekly administered IFN-ß. Spinal cords obtained from inIFN-ß-NPs-treated EAE mice showed fewer inflammatory foci and demyelination, lower expression of antigen-presenting and costimulatory proteins on CD11b+ cells, and lower astrocyte and microglia activation than control mice. Therefore, IFN-ß treatment at tested doses was effective in promoting clinical recovery and control of neuroinflammation in EAE only when associated with NPs. Overall, inIFN-ß-NPs represent a potential, effective, non-invasive, and low-cost therapy for MS.


Assuntos
Encefalomielite Autoimune Experimental , Esclerose Múltipla , Nanopartículas , Administração Intranasal , Animais , Encefalomielite Autoimune Experimental/tratamento farmacológico , Interferon beta/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Esclerose Múltipla/tratamento farmacológico , Distribuição Tecidual
7.
Diabetol Metab Syndr ; 12: 66, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32774470

RESUMO

BACKGROUND: In type I diabetes mellitus (T1DM) pancreatic ß cells are destroyed. Treatment entails exogenous insulin administration and strict diet control, yet optimal glycemic control is hardly attainable. Islet transplant could be an alternative in patients with poor glycemic control, but inefficient islet purification and autoimmune response of patients is still a challenge. For these reasons, it is necessary to explore new cellular sources and immunological isolation methods oriented to develop T1DM cell-based therapies. AIMS: We postulate human adipose-derived stem cell (hASC) as an adequate source to generate pancreatic islet cells in vitro, and to produce islet-like structures. Furthermore, we propose microencapsulation of these aggregates as an immunological isolation strategy. METHODS: hASC obtained from lipoaspirated fat tissue from human donors were differentiated in vitro to insulin (Ins) and glucagon (Gcg) producing cells. Then, insulin producing cells (IPC) and glucagon producing cells (GPC) were cocultured in low adhesion conditions to form cellular aggregates, and later encapsulated in a sodium alginate polymer. Expression of pancreatic lineage markers and secretion of insulin or glucagon in vitro were analyzed. RESULTS: The results show that multipotent hASC efficiently differentiate to IPC and GPC, and express pancreatic markers, including insulin or glucagon hormones which they secrete upon stimulation (fivefold for insulin in IPC, and fourfold for glucagon, compared to undifferentiated cells). In turn, calculation of the Feret diameter and area of cellular aggregates revealed mean diameters of ~ 80 µm, and 65% of the aggregates reached 4000 µm2 at 72 h of formation. IPC/GPC aggregates were then microencapsulated in sodium-alginate polymer microgels, which were found to be more stable when stabilized with Ba2+, yielding average diameters of ~ 300 µm. Interestingly, Ba2+-microencapsulated aggregates respond to high external glucose with insulin secretion. CONCLUSIONS: The IPC/GPC differentiation process from hASC, followed by the generation of cellular aggregates that are later microencapsulated, could represent a possible treatment for T1DM.

8.
Mar Drugs ; 18(6)2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32604880

RESUMO

Astaxanthin (ASX) is a carotenoid pigment with strong antioxidant properties. We have reported previously that ASX protects neurons from the noxious effects of amyloid-ß peptide oligomers, which promote excessive mitochondrial reactive oxygen species (mROS) production and induce a sustained increase in cytoplasmic Ca2+ concentration. These properties make ASX a promising therapeutic agent against pathological conditions that entail oxidative and Ca2+ dysregulation. Here, we studied whether ASX protects neurons from N-methyl-D-aspartate (NMDA)-induced excitotoxicity, a noxious process which decreases cellular viability, alters gene expression and promotes excessive mROS production. Incubation of the neuronal cell line SH-SY5Y with NMDA decreased cellular viability and increased mitochondrial superoxide production; pre-incubation with ASX prevented these effects. Additionally, incubation of SH-SY5Y cells with ASX effectively reduced the basal mROS production and prevented hydrogen peroxide-induced cell death. In primary hippocampal neurons, transfected with a genetically encoded cytoplasmic Ca2+ sensor, ASX also prevented the increase in intracellular Ca2+ concentration induced by NMDA. We suggest that, by preventing the noxious mROS and Ca2+ increases that occur under excitotoxic conditions, ASX could be useful as a therapeutic agent in neurodegenerative pathologies that involve alterations in Ca2+ homeostasis and ROS generation.


Assuntos
Cálcio/metabolismo , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Células Cultivadas , Hipocampo/efeitos dos fármacos , Humanos , N-Metilaspartato/toxicidade , Neuroblastoma , Neurônios/efeitos dos fármacos , Cultura Primária de Células , Ratos , Xantofilas/farmacologia
9.
Wounds ; 32(3): E14-E18, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32335521

RESUMO

INTRODUCTION: Diabetic foot ulcers may lead to nontraumatic amputations of the foot, leading to a decrease in patient quality of life. Transmetatarsal amputations (TMAs) represent an effective surgical procedure in cases of severe foot infection, but the tissue reconstruction is complicated and additional procedures should be considered. The present case report evaluates the wound closure of an open TMA in a patient with diabetes treated with a new aerogel composed of chitosan (ChS) and chondroitin sulphate (CS), without needing a skin graft. CASE REPORT: A 72-year-old man with diabetes and a history of successive amputations was admitted to a hospital in Valdivia, Chile, due to a severe infection of toes 2 and 4 of the right foot. After the diagnosis of gangrene and osteomyelitis, the patient underwent a TMA of his right forefoot. The surgeon proposed the incorporation of ChS and CS aerogels to accelerate wound healing to avoid another surgical procedure. The TMA surgical wound area closed 50% after day 28 from starting treatment with aerogels. Complete closure was achieved at day 94 of treatment with aerogels, with good epithelial tissue and favorable cosmetic results and without residual limb deformities. The patient experienced minimal physical and psychological impairment from the procedure. Other surgical procedures were not necessary. CONCLUSIONS: Due to the results of this patient, use of ChS and CS aerogels could represent an alternative treatment for forefoot TMA wound closure and prevent further surgical procedures, such as skin grafting. Future works should consider a larger number of cases.


Assuntos
Amputação Cirúrgica , Quitosana/farmacologia , Sulfatos de Condroitina/farmacologia , Diabetes Mellitus Tipo 2/complicações , Pé Diabético/cirurgia , Metatarso/cirurgia , Cicatrização/efeitos dos fármacos , Idoso , Pé Diabético/etiologia , Gangrena/etiologia , Géis , Humanos , Masculino , Osteomielite/etiologia
10.
Nanomaterials (Basel) ; 9(7)2019 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-31261871

RESUMO

We report on the design, development, characterization, and a preliminary cellular evaluation of a novel solid material. This material is composed of low-molecular-weight hyaluronic acid (LMWHA) and polyarginine (PArg), which generate aqueous ionic nanocomplexes (INC) that are then freeze-dried to create the final product. Different ratios of LMWHA/PArg were selected to elaborate INC, the size and zeta potential of which ranged from 100 to 200 nm and +25 to -43 mV, respectively. Turbidimetry and nanoparticle concentration analyses demonstrated the high capacity of the INC to interact with increasing concentrations of LMWHA, improving the yield of production of the nanostructures. Interestingly, once the selected formulations of INC were freeze-dried, only those comprising a larger excess of LMWHA could form reproducible sponge formulations, as seen with the naked eye. This optical behavior was consistent with the scanning transmission electron microscopy (STEM) images, which showed a tendency of the particles to agglomerate when an excess of LMWHA was present. Mechanical characterization evidenced low stiffness in the materials, attributed to the low density and high porosity. A preliminary cellular evaluation in a fibroblast cell line (RMF-EG) evidenced the concentration range where swollen formulations did not affect cell proliferation (93-464 µM) at 24, 48, or 72 h. Considering that the reproducible sponge formulations were elaborated following inexpensive and non-contaminant methods and comprised bioactive components, we postulate them with potential for biomedical purposes. Additionally, this systematic study provides important information to design reproducible porous solid materials using ionic nanocomplexes.

11.
Mol Pharm ; 16(7): 2892-2901, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31181908

RESUMO

To date, a large number of active molecules are hydrophilic and aromatic low molecular-weight drugs (HALMD). Unfortunately, the low capacity of these molecules to interact with excipients and the fast release when a formulation containing them is exposed to biological media jeopardize the elaboration of drug delivery systems by using noncovalent interactions. In this work, a new, green, and highly efficient methodology to noncovalently attach HALMD to hydrophilic aromatic polymers to create nanocarriers is presented. The proposed method is simple and consists in mixing an aqueous solution containing HALMD (model drugs: imipramine, amitriptyline, or cyclobenzaprine) with another aqueous solution containing the aromatic polymer [model polymer: poly(sodium 4-styrenesulfonate) (PSS)]. NMR experiments demonstrate strong chemical shifting of HALMD aromatic rings when interacting with PSS, evidencing aromatic-aromatic interactions. Ion pair formation and aggregation produce the collapse of the system in the form of nanoparticles. The obtained nanocarriers are spheroidal, their size ranging between 120 and 170 nm, and possess low polydispersity (≤0.2) and negative zeta potential (from -60 to -80 mV); conversely, the absence of the aromatic group in the polymer does not allow the formation of nanostructures. Importantly, in addition to high drug association efficiencies (≥90%), the formed nanocarriers show drug loading values never evidenced for other systems comprising HALMD, reaching ≈50%. Diafiltration and stopped flow experiments evidenced kinetic drug entrapment governed by molecular rearrangements. Importantly, the nanocarriers are stable in suspension for at least 18 days and are also stable when exposed to different high ionic strength, pH, and temperature values. Finally, they are transformable to a reconstitutable dry powder without losing their original characteristics. Considering the large quantity of HALMD with importance in therapeutics and the simplicity of the presented strategy, we envisage these results as the basis to elaborate a number of drug delivery systems with applications in different pathologies.


Assuntos
Antidepressivos Tricíclicos/química , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/métodos , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas/química , Polímeros/química , Ácidos Sulfônicos/química , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Peso Molecular , Nanomedicina/métodos , Tamanho da Partícula
12.
Nanoscale ; 10(47): 22612-22622, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30484463

RESUMO

Curcumin is widely considered beneficial to human health, but insolubility and instability greatly hamper reproducible exploitation of the advantageous traits. Here we report on the development, characterization and evaluation of a curcumin-loaded nanoemulsion (CUR-NEM) that is highly effective in preventing post-surgery tumor reincidence and metastasis. The method of fabrication utilized safe excipients and generated particles of 200 nm (PDI ≤ 0.2) with negative zeta potential (-30 mV) and a high yield of curcumin (95%), which can be converted by lyophilization to a dry powder. In vitro assays showed that CUR-NEM is safe in non-cancerous human cells (HEK-293T) and preferentially cytotoxic in gastric (AGS), colon (HT29-ATCC, HT29-US), breast (MDA-MB-231) and melanoma (B16F10) cells. In addition, in melanoma cells the nanoformulation increases intracellular curcumin accumulation and reactive oxygen species (ROS) formation, while preventing cell-migration and invasion. In vivo studies in C57BL/6 mice demonstrated that a single dose, applied topically to the wounded area after surgical excision of primary tumors formed upon subcutaneous injection of syngeneic B16F10 cells, was sufficient to completely prevent reincident tumor growth and spontaneous lung metastasis, while in untreated animals 70% reincidence and metastasis were observed. In vivo experiments also showed that the fluorescence signal due to curcumin was maintained at least 15 days after topical application of CUR-NEM, while when administered in DMSO the curcumin signal disappeared within 4 days. Importantly, the administration of a dose 22 times larger than that applied topically to animals after tumor surgery did not alter biochemical parameters. Due to the safety and efficacy of the formulation, we envisage it as ideal for topical application in cancer patients following surgery, to prevent tumor reincidence and metastasis. In addition, other routes of administration/protocols could also be proposed to treat/prevent malignant tumors in patients.


Assuntos
Curcumina/química , Emulsões/química , Neoplasias/patologia , Células A549 , Adenocarcinoma/patologia , Animais , Linhagem Celular Tumoral , Movimento Celular , Sobrevivência Celular , Portadores de Fármacos/química , Células HEK293 , Humanos , Neoplasias Pulmonares/patologia , Melanoma Experimental , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Metástase Neoplásica , Espécies Reativas de Oxigênio/metabolismo , Solventes/química
13.
Curr Top Med Chem ; 18(14): 1242-1251, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30095055

RESUMO

Collagen, the most abundant component in mammalian tissues, has a crucial impact at skin level. Both promotion and maintenance of cross-linked collagen at the skin are critical to sustain the functionality and appearance of that tissue. Lysyl oxidases, also known as LOX enzymes, are the major collagen cross-linking enzymes that play a pivotal role in homeostasis. This minireview summarizes evidence that describes an amino oxidase-like activity, which could be attributed to polyphenols, or where polyphenols could be required. We also discuss some available collagen formulations and the scientific evidence that describes the impact on dermal extracellular matrix. In addition, information about encapsulation strategies to carry polyphenols, and some examples are also provided.


Assuntos
Colágeno , Polifenóis , Pele , Aminoácido Oxirredutases , Animais , Humanos , Estrutura Molecular
14.
Molecules ; 23(5)2018 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-29783629

RESUMO

Here we report the incorporation of gold nanostructures (nanospheres or nanorods, functionalized with carboxylate-end PEG) and curcumin oil-in-water (O/W) nanoemulsions (CurNem) into alginate microgels using the dripping technique. While gold nanostructures are promising nanomaterials for photothermal therapy applications, CurNem possess important pharmacological activities as reported here. In this sense, we evaluated the effect of CurNem on cell viability of both cancerous and non-cancerous cell lines (AGS and HEK293T, respectively), demonstrating preferential toxicity in cancer cells and safety for the non-cancerous cells. After incorporating gold nanostructures and CurNem together into the microgels, microstructures with diameters of 220 and 540 µm were obtained. When stimulating microgels with a laser, the plasmon effect promoted a significant rise in the temperature of the medium; the temperature increase was higher for those containing gold nanorods (11⁻12 °C) than nanospheres (1⁻2 °C). Interestingly, the incorporation of both nanosystems in the microgels maintains the photothermal properties of the gold nanostructures unmodified and retains with high efficiency the curcumin nanocarriers. We conclude that these results will be of interest to design hydrogel formulations with therapeutic applications.


Assuntos
Portadores de Fármacos/química , Ouro/química , Nanosferas/química , Nanotubos/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Curcumina/administração & dosagem , Curcumina/química , Liberação Controlada de Fármacos , Emulsões , Géis , Células HEK293 , Humanos , Lasers , Tamanho da Partícula , Fotoquimioterapia/métodos , Polietilenoglicóis/química , Solubilidade , Propriedades de Superfície
15.
Food Chem ; 253: 71-78, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29502846

RESUMO

The development of fat replacers to obtain healthier/functional foods is a constant challenge. With this aim, double emulsions (DE) with a blend of olive, linseed and fish oils as oil phase were developed. To prevent the oxidation of these oils, gallic acid and quercetin were incorporated in the internal and the external aqueous phase (W2), respectively, according to a factorial design. Considering the low solubility of quercetin in water, it was included in O/W nanoemulsions (QN), thus being freely dispersible in W2. The antioxidant activity in DE was attributed to QN, which significantly improved the oxidative stability of DE/QN. Furthermore, DE/QN showed good physical stability with a limited coalescence during storage at 4 °C for 28 days, significantly longer than time usually required for food ingredients. Therefore, DE/QN could be used as potential fat replacer in a variety of food formulations, providing blends of fatty acids consistent with dietary recommendations.


Assuntos
Ácidos Graxos/química , Ácido Gálico/química , Nanoestruturas/química , Quercetina/química , Água/química , Emulsões , Solubilidade
16.
J Biomed Mater Res B Appl Biomater ; 106(6): 2464-2471, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29424958

RESUMO

In this study, highly neutralized, highly porous, and ultralight polymeric aerogels prepared from aqueous colloidal suspensions of chitosan (CS) and chondroitin sulfate (ChS) nanocomplexes, formulated as quasi-equimolar amounts of both, are described. These aerogels were designed as healing agents under the inspiration of minimizing the amount of matter applied to wounds, reducing the electrostatic potential of the material and avoiding covalent cross-linkers in order to decrease metabolic stress over wounds. Aerogels synthesized under these criteria are biocompatible and provide specific properties for the induction of wound healing. They do not affect neither the metabolic activity of cultured 3T3 fibroblasts nor the biochemical parameters of experimental animals, open wounds close significantly faster and, unlike control wounds, complete reepithelialization and scarring can be attained 14 days after surgery. Because of its hydration abilities, rapid adaptation to the wound bed and the early accelerator effect of wound closure, the CS/ChS aerogels appear to be functional inducers of the healing. Previous information show that CS/ChS aerogels improve wound bed quality, increase granulation tissue and have pain suppressive effect. CS/ChS aerogels are useful as safe, inexpensive and easy to handle materials for topical applications, such as skin chronic wounds. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2464-2471, 2018.


Assuntos
Sulfatos de Condroitina , Teste de Materiais , Pele , Cicatrização/efeitos dos fármacos , Células 3T3 , Administração Tópica , Animais , Quitosana/química , Quitosana/farmacologia , Sulfatos de Condroitina/química , Sulfatos de Condroitina/farmacologia , Géis , Masculino , Camundongos , Porosidade , Coelhos , Pele/lesões , Pele/metabolismo , Pele/patologia
17.
Macromol Rapid Commun ; 37(21): 1729-1734, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27616076

RESUMO

The formation of redox-active, totally organic nanoparticles in water is achieved following a strategy similar to that used to form metal nanoparticles. It is based on two fundamental concepts: i) complexation through aromatic-aromatic interactions of a water-soluble precursor aromatic molecule with polyelectrolytes bearing complementary charged aromatic rings, and ii) reduction of the precursor molecule to achieve stabilized nanoparticles. Thus, formazan nanoparticles are synthesized by reduction of a tetrazolium salt with ascorbic acid using polyelectrolytes bearing benzene sulfonate residues of high linear aromatic density, but cannot be formed in the presence of nonaromatic polyelectrolytes. The red colored nanoparticles are efficiently encapsulated in calcium alginate beads, showing macroscopic homogeneity. Bleaching kinetics with chlorine show linear rates on the order of tenths of milli-meters per minute. A linear behavior of the dependence of the rate of bleaching on the chlorine concentration is found, showing the potential of the nanoparticles for chlorine sensing.


Assuntos
Eletrólitos/química , Formazans/química , Hidrocarbonetos Aromáticos/química , Nanopartículas/química , Polímeros/química , Sais de Tetrazólio/química , Água/química , Oxirredução , Tamanho da Partícula , Propriedades de Superfície
18.
Curr Pharm Des ; 21(29): 4329-41, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26323420

RESUMO

The treatment of skin wounds represents an important research area due to the important physiological and aesthetic role of this tissue. During the last years, nanoparticles have emerged as important platforms to treat skin wounds. Silver, gold, and copper nanoparticles, as well as titanium and zinc oxide nanoparticles, have shown potential therapeutic effects on wound healing. Due to their specific characteristics, nanoparticles such as nanocapsules, polymersomes, solid lipid nanoparticles, and polymeric nanocomplexes are ideal vehicles to improve the effect of drugs (antibiotics, growth factors, etc.) aimed at wound healing. On the other hand, if active excipients are added during the formulation, such as hyaluronate or chitosan, the nanomedicine could significantly improve its potential. In addition, the inclusion of nanoparticles in different pharmaceutical materials may enhance the beneficial effects of the formulations, and allow achieving a better dose control. This paper aims at reviewing significant findings in the area of nanoparticles and wound treatment. Among the reviewed topics, we underline formulations comprising inorganic, polymeric, surfactant self-assembled, and lipid nanosystems. Among the drugs included in the nanoformulations, the paper refers to antibiotics, natural extracts, proteins, and growth factors, among others. Finally, the paper also addresses nanoparticles embedded in secondary vehicles (fibers, dressings, hydrogels, etc.) that could improve their application and/or upgrade the release profile of the active.


Assuntos
Nanopartículas Metálicas/administração & dosagem , Ferimentos e Lesões/tratamento farmacológico , Animais , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Sistemas de Liberação de Medicamentos/métodos , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/administração & dosagem , Peptídeos e Proteínas de Sinalização Intercelular/uso terapêutico , Nanopartículas Metálicas/uso terapêutico , Pele/efeitos dos fármacos , Pele/lesões , Cicatrização/efeitos dos fármacos
19.
Nanomedicine (Lond) ; 10(2): 253-69, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25600970

RESUMO

Retinoids are lipophilic compounds that are highly used in cosmetics/therapeutics for skin disorders. Conventional formulations are limited by poor water solubility, high chemical/photochemical instability and the irritation of retinoids. Interestingly, lipid nanoparticles enable the administration of retinoids in aqueous media, providing drug stabilization and controlled release. Recently, it has been demonstrated that retinoids in solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions and nanocapsules can decrease degradation, improve targeting and enhance efficacy for the treatment of skin disorders. This article focuses on the formulation, fabrication, characterization and in vitro/in vivo evaluation of solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions and nanocapsules loaded with retinoids for skin administration. Furthermore, the incorporation of these lipid nanoparticles into secondary vehicles is discussed.


Assuntos
Lipídeos/química , Nanopartículas/química , Retinoides/administração & dosagem , Retinoides/química , Administração Cutânea , Animais , Humanos , Pele/metabolismo , Absorção Cutânea
20.
J Pharm Sci ; 104(3): 1141-52, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25557590

RESUMO

The association efficiency of oxytetracycline (OTC) to pharmaceutical available, ionic oil-in-water nanoemulsions is studied. Theoretical mathematical developments allowed us to differentiate by diafiltration (DF) between thermodynamically and kinetically controlled binding of the drug to the nanoemulsions, and relate these important magnitudes to the association efficiency. The nanoemulsions have been prepared by the solvent displacement technique in the presence of cationic and anionic surfactants. The resulting nanoemulsions were stable at 4°C and 25°C for 60 days, have a size of ∼ 200 nm, showing polydispersity indexes ranging between 0.11 and 0.23, and present zeta potentials ranging between -90 and +60 mV, depending on the charge of the surfactants used. The zeta potential of the nanoemulsions influenced the interaction with OTC, having three ionic forms at different pH, namely, cationic, zwitterionic, and anionic. DF proved to be a powerful tool for the quantification of the drug association efficiency, achieving values up to 84%. Furthermore, this technique allowed obtaining different values of the drug fractions reversibly bound (11%-57%) and irreversibly bound (10%-40%) to the nanoemulsions depending on the surfactants used and pH. These findings may be useful for the development of new drug delivery systems, and as routine assays in academia and pharmaceutical industries.


Assuntos
Antibacterianos/química , Portadores de Fármacos , Filtração/métodos , Nanopartículas , Óleos/química , Oxitetraciclina/química , Tecnologia Farmacêutica/métodos , Água/química , Ânions , Cátions , Química Farmacêutica , Estabilidade de Medicamentos , Emulsões , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Cinética , Modelos Químicos , Nanotecnologia , Solubilidade , Propriedades de Superfície , Tensoativos/química , Temperatura
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