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1.
J Environ Sci (China) ; 85: 147-155, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471021

RESUMO

Polymer hydrogel-based materials have been shown to act as novel Fenton catalysts for water treatment, but the rational design of hydrogel-based catalysts with good stability has been a great challenge. To increase the stability and activity of polymer-based Fenton catalysts, uniform urchin-like α-Fe2O3 was grown in situ in a PVA carrier matrix here. PVA molecules promoted the growth of urchin-like α-Fe2O3, and then the PVA hydrogel acted as a barrier and carrier to reduce agglomeration. Through coordination by hydroxyl groups, PVA had good combination with Fe ions and α-Fe2O3. The formation of Fe-O-C bonds between iron oxides and polymers was reported for the first time, enhancing the material stability during catalysis. Under higher PVA concentrations, the resulting composite hydrogel could generate more ˙OH due to the increase in the number of active sites because of the hairy urchin-like structure. In tetracycline degradation through a heterogeneous Fenton reaction, the resulting material had good catalytic activity from pH 2 to pH 10 with low iron leaching, good reusability and remained at a level of nearly 90% after five consecutive cycles. Density functional theory calculations were used to further prove the mechanism of structural change of the iron oxides. The HOMO and LUMO energies of the iron oxides changed from 5.428 and 4.899 eV to 5.926 and 5.310 eV, indicating that the presence of PVA could influence the charge of the iron atom. The results provide new insights into the preparation of polymer hydrogel-based heterogeneous Fenton catalysts with enhanced stability for water treatment.


Assuntos
Hidrogéis/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Compostos Férricos , Peróxido de Hidrogênio/química , Polímeros
2.
Chem Commun (Camb) ; 55(66): 9865-9868, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31364624

RESUMO

Au hydrogel with a well-defined nanowire network was rationally designed through one-step dopamine-induced self-assembly. Due to the porous nanostructure along with the polydopamine induced accumulation and interfacial electron transfer effects, the resulting Au hydrogel nanozyme exhibits enhanced glucose oxidase-like activity and peroxidase-like activity, with a biomimetic cascade catalysis.


Assuntos
Biomimética , Dopamina/química , Glucose Oxidase/química , Ouro/química , Hidrogéis/química , Nanopartículas Metálicas/química , Peroxidase/química , Catálise , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxirredução
3.
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
4.
Int J Nanomedicine ; 14: 5125-5133, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371951

RESUMO

Purpose: The frequent usage of various lighting screens has made dry eye syndrome an increasingly serious phenomenon. To relieve this global problem, we have developed a photothermal conversion hydrogel based mini-eye patch. Methods: Gold nanoparticles (GNRs) were synthesized by a seed-mediated method, and then used as the inner cores to grow palladium (Pd) shell by PdCl42-reduction. Then, gelatin was added to prepare GNRs @ Pd hydrogel eye patch by genipin cross-linking. We implanted temperature sensitive ink (complex composed of amino resin and styrene maleic anhydride copolymer) in the eye patch, which could change color at different temperatures. Heating performance of the eye patch was accessed with an infrared temperature profile and the circulating temperature experiment. The safety assessment of the eye patch was conducted by H&E staining of the mouse's eyelid skin and CCK-8 assay. A Keratograph 5M noninvasive ocular surface analyzer was used to assess the impact of eye patches on dry eyes. Results: It was found that GNRs @ Pd hydrogel eye patches could sense various visible light and responded by heating up spontaneously. Results from the CCK-8 assay and H&E staining showed that the eye patch has good safety performance. Measurements of the first noninvasive tear break-up time (NITBUT), the average NITBUT, the tear meniscus height (TMH), combined with red eye analysis, further demonstrated the patch's eye-protective properties. Conclusion: After being pasted to the lacrimal gland, the hydrogel patch converted various light irradiations into heat and stimulated the lacrimal gland to produce more tears to relieve dry eye. The built-in temperature-sensitive ink can play an important role in warning people of their excessive eye usage. Because this recyclable strategy does not interfere with normal eye use, it is thus more environmentally friendly and convenient than ordinary infrared eyewear.


Assuntos
Síndromes do Olho Seco/terapia , Olho/patologia , Hidrogéis/química , Luz , Temperatura Ambiente , Adolescente , Adulto , Animais , Linhagem Celular , Feminino , Ouro/química , Humanos , Masculino , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Camundongos , Coelhos , Ratos Sprague-Dawley , Adulto Jovem
5.
Int J Nanomedicine ; 14: 5449-5475, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409998

RESUMO

Purpose: We created and evaluated an enhanced topical delivery system featuring a combination of highly skin-permeable growth factors (GFs), quercetin (QCN), and oxygen; these synergistically accelerated re-epithelialization and granulation tissue formation of/in diabetic wounds by increasing the levels of GFs and antioxidants, and the oxygen partial pressure, at the wound site. Methods: To enhance the therapeutic effects of exogenous administration of GFs for the treatment of diabetic wounds, we prepared highly skin-permeable GF complexes comprised of epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), platelet-derived growth factor-A (PDGF-A), and basic fibroblast growth factor (bFGF), genetically attached, via the N-termini, to a low-molecular-weight protamine (LMWP) to form LMWP-EGF, LMWP-IGF-I, LMWP-PDGF-A, and LMWP-bFGF, respectively. Furthermore, quercetin (QCN)- and oxygen-carrying 1-bromoperfluorooctane (PFOB)-loaded nanoemulsions (QCN-NE and OXY-PFOB-NE) were developed to improve the topical delivery of QCN and oxygen, respectively. After confirming the enhanced penetration of LMWP-GFs, QCN-NE, and oxygen delivered from OXY-PFOB-NE across human epidermis, we evaluated the effects of combining LMWP-GFs, QCN-NE, and OXY-PFOB-NE on proliferation of keratinocytes and fibroblasts, and the chronic wound closure rate of a diabetic mouse model. Results: The optimal ratios of LMWP-EGF, LMWP-IGF-I, LMWP-PDGF-A, LMWP-bFGF, QCN-NE, and OXY-PFOB-NE were 1, 1, 0.02, 0.02, 0.2, and 60, respectively. Moreover, a Carbopol hydrogel containing LMWP-GFs, QCN-NE, and OXY-PFOB-NE (LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL) significantly improved scratch-wound recovery of keratinocytes and fibroblasts in vitro compared to that afforded by hydrogels containing each component alone. LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL significantly accelerated wound-healing in a diabetic mouse model, decreasing wound size by 54 and 35% compared to the vehicle and LMWP-GFs, respectively. Conclusion: LMWP-GFs/QCN-NE/OXY-PFOB-NE-GEL synergistically accelerated the healing of chronic wounds, exerting both rapid and prolonged effects.


Assuntos
Diabetes Mellitus/patologia , Hidrogéis/química , Fator de Crescimento Insulin-Like I/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Oxigênio/metabolismo , Quercetina/farmacologia , Absorção Cutânea , Cicatrização/efeitos dos fármacos , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Colágeno/biossíntese , Modelos Animais de Doenças , Emulsões/química , Fator de Crescimento Epidérmico/farmacologia , Epiderme/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Peso Molecular , Nanopartículas/química , Nanopartículas/ultraestrutura , Octanos/química , Fator de Crescimento Derivado de Plaquetas/farmacologia , Protaminas/química , Absorção Cutânea/efeitos dos fármacos
6.
J Photochem Photobiol B ; 197: 111530, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31279287

RESUMO

A novel nano-formulations of biocompatible, biodegradable and thermo-responsive graphene quantum dots (GQDs) loaded dextran/poly(N-isopropylacrylamide) (Dex/PNIPAM) copolymeric matrix was synthesized and analyzed the materials characterization, sustained drug delivery system, tissue feasibility in the tissue implantation site. This research report was aimed to grafting and functionalizing thermo-responsive (Dex/PNIPAM) copolymeric composite with presence of graphene quantum dots to achieve thermal responsive drug delivery (TrDD) with no harm effect in the implantation site. The synthesized GQD by using ionic liquid were evaluated by spectroscopic (DLS, PL, XRD and Raman spectroscopy) and Transmission electron microscopic analysis (TEM). The ultra-small GQDs loaded Dex/PNIPAM and was appeared to be asymmetric and open uniform porous structure, which can be significantly favorable for cell uptake and greatly influenced to be an effective drug carrier into the cellular compartment with good fluid flow. The PNIPAM polymeric composite were exhibited sustained and enhanced drug release percentages with increasing temperature at above low critical solution temperature (LCST) is 39 °C comparable to the cumulative drug release profile of below LCST (32 °C), which demonstrated that thermo-responsive polymer was played a significant role in the delivery system. The treated group of GQDs-Dex/PNIPAM was observed that no inflammation and shows noteworthy stromal cell infiltration, demonstrating that the synthesized drug carriers did not harm to the nerves and tissues and only was responsible for the pain management.


Assuntos
Buprenorfina/química , Portadores de Fármacos/química , Grafite/química , Hidrogéis/química , Manejo da Dor , Pontos Quânticos/química , Resinas Acrílicas/química , Animais , Buprenorfina/uso terapêutico , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dextranos/química , Portadores de Fármacos/farmacologia , Feminino , Corantes Fluorescentes/química , Glicóis/química , Hidrogéis/farmacologia , Camundongos , Músculo Esquelético/patologia , Dor/tratamento farmacológico , Ratos , Ratos Sprague-Dawley
7.
Chem Commun (Camb) ; 55(61): 9019-9022, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31290863

RESUMO

DNA nanohydrogel assembled AuNPs were proposed as a high-throughput multidimensional sensing strategy for small molecule reductant profiling in rat brain. The equilibrium among AuNPs, DNA nanohydrogel and targets produced a unique fingerprint-like pattern for differentiating the reducing capacity.


Assuntos
Encéfalo/metabolismo , DNA de Cadeia Simples/química , Ouro/química , Hidrogéis/química , Nanopartículas Metálicas/química , Substâncias Redutoras/análise , Animais , Colorimetria/métodos , Análise Discriminante , Glutationa/líquido cefalorraquidiano , Oxirredução , Tamanho da Partícula , Ratos
8.
J Microbiol Biotechnol ; 29(7): 1078-1082, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31280528

RESUMO

Poly-γ-glutamate (γ-PGA) has various applications due to its desirable characteristics in terms of safety and biodegradability. Previous studies have been conducted on γ-PGA hydrogels produced by γ-ray irradiation, but these hydrogels have proved unstable in solutions. This study was conducted to enable the γ-PGA hydrogel to maintain a stable form in solutions. The γ-PGA mixture for UV-irradiation was prepared with a cross-linker (N,N,N-trimethyl-3-[(2- methylacryloyl)amino]propan-1-aminium). Both γ-PGA hydrogels' characteristics, including stability in solutions, were examined. The UV-irradiated γ-PGA hydrogel maintained a stable form during the nine weeks of the study, but the γ-ray irradiated hydrogel dissolved after one week.


Assuntos
Raios gama , Hidrogéis/química , Ácido Poliglutâmico/análogos & derivados , Raios Ultravioleta , Materiais Biocompatíveis/química , Reagentes para Ligações Cruzadas/química , Hidrogéis/síntese química , Concentração de Íons de Hidrogênio , Ácido Poliglutâmico/química , Soluções , Viscosidade
9.
J Nanobiotechnology ; 17(1): 82, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291960

RESUMO

Skin damages are defined as one of most common lesions people suffer from, some of wounds are notoriously difficult to eradicate such as chronic wounds and deep burns. Existing wound therapies have been proved to be inadequate and far from satisfactory. The cutting-edge nanotechnology offers an unprecedented opportunity to revolutionize and invent new therapies or boost the effectiveness of current medical treatments. In particular, the nano-drug delivery systems anchor bioactive molecules to applied area, sustain the drug release and explicitly enhance the therapeutic efficacies of drugs, thus making a fine figure in field relevant to skin regeneration. This review summarized and discussed the current nano-drug delivery systems holding pivotal potential for wound healing and skin regeneration, with a special emphasis on liposomes, polymeric nanoparticles, inorganic nanoparticles, lipid nanoparticles, nanofibrous structures and nanohydrogel.


Assuntos
Materiais Biocompatíveis/química , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Fenômenos Fisiológicos da Pele , Cicatrização/efeitos dos fármacos , Animais , Liberação Controlada de Fármacos , Humanos , Hidrogéis/química , Lipídeos/química , Lipossomos/química , Polímeros/química , Regeneração
10.
Nat Commun ; 10(1): 3098, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31308369

RESUMO

Design strategies for small diameter vascular grafts are converging toward native-inspired tissue engineered grafts. A new automated technology is presented that combines a dip-spinning methodology for depositioning concentric cell-laden hydrogel layers, with an adapted solution blow spinning (SBS) device for intercalated placement of aligned reinforcement nanofibres. This additive manufacture approach allows the assembly of bio-inspired structural configurations of concentric cell patterns with fibres at specific angles and wavy arrangements. The middle and outer layers were tuned to structurally mimic the media and adventitia layers of native arteries, enabling the fabrication of small bore grafts that exhibit the J-shape mechanical response and compliance of human coronary arteries. This scalable automated system can fabricate cellularized multilayer grafts within 30 min. Grafts were evaluated by hemocompatibility studies and a preliminary in vivo carotid rabbit model. The dip-spinning-SBS technology generates constructs with native mechanical properties and cell-derived biological activities, critical for clinical bypass applications.


Assuntos
Bioprótese , Prótese Vascular , Vasos Coronários/anatomia & histologia , Engenharia Tecidual/métodos , Animais , Implante de Prótese Vascular/instrumentação , Implante de Prótese Vascular/métodos , Ponte de Artéria Coronária/instrumentação , Ponte de Artéria Coronária/métodos , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Hidrogéis/química , Teste de Materiais/métodos , Modelos Animais , Coelhos , Resistência à Tração
11.
Soft Matter ; 15(30): 6171-6179, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31318005

RESUMO

In this work, we prepared locust bean gum (LBG)/gellan gum (Gg) double network (DN) hydrogels based on pH-sensitive borate-ester bonds in the LBG network and hydrogen-bond-associated double-helix bundles in the Gg network by using two novel natural polysaccharide polymers. The DN hydrogels with optimized Gg and borax concentrations exhibit good mechanical properties (the fracture tensile stress is almost three times that of the LBG single network hydrogel). Because of their unique thermo- and pH-sensitive DN structure, the LBG/Gg DN hydrogels also show excellent self-healing, thermo-processability, and pH-driven shape memory properties. Such novel DN hydrogels demonstrate strong potentiality in many challenging applications such as biomedicine, soft robotics and other fields.


Assuntos
Galactanos/química , Hidrogéis/química , Mananas/química , Gomas Vegetais/química , Polissacarídeos Bacterianos/química , Concentração de Íons de Hidrogênio , Fenômenos Mecânicos
12.
Adv Mater ; 31(33): e1902462, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31265196

RESUMO

The controlled presentation of proteins from and within materials remains of significant interest for many bioengineering applications. Though "smart" platforms offer control over protein release in response to a single external cue, no strategy has been developed to trigger delivery in response to user-specified combinations of environmental inputs, nor to independently control the release of multiple species from a homogenous material. Here, a modular semisynthetic scheme is introduced to govern the release of site-specifically modified proteins from hydrogels following Boolean logic. A sortase-mediated transpeptidation reaction is used to generate recombinant proteins C-terminally tethered to gels through environmentally sensitive degradable linkers. By varying the connectivity of multiple stimuli-labile moieties within these customizable linkers, YES/OR/AND control of protein release is exhaustively demonstrated in response to one and two-input combinations involving enzyme, reductant, and light. Tethering of multiple proteins each through a different stimuli-sensitive linker permits their independent and sequential release from a common material. It is expected that these methodologies will enable new opportunities in tissue engineering and therapeutic delivery.


Assuntos
Aminoaciltransferases/química , Proteínas de Bactérias/química , Materiais Biocompatíveis/química , Cisteína Endopeptidases/química , Sistemas de Liberação de Medicamentos/métodos , Hidrogéis/química , Proteínas Recombinantes/química , Aminoaciltransferases/administração & dosagem , Proteínas de Bactérias/administração & dosagem , Cisteína Endopeptidases/administração & dosagem , Dissulfetos/química , Liberação Controlada de Fármacos , Humanos , Luz , Oxirredução , Peptídeos/química , Fotólise , Polietilenoglicóis/química , Proteínas Recombinantes/administração & dosagem , Staphylococcus aureus/enzimologia
13.
Biomater Sci ; 7(9): 3906-3917, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31322163

RESUMO

Cardiovascular diseases represent a major socio-economic burden. In recent years, considerable effort has been invested in optimizing cell delivery strategies to advance cell transplantation therapies to restore heart function for example after an infarct. A particular issue is that the implantation of cells using a non-electroconductive matrix potentially causes arrhythmia. Here, we demonstrate that our hydrazide-functionalized nanotubes-pericardial matrix-derived electroconductive biohybrid hydrogel provides a suitable environment for maturation of human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes. hiPSC-derived cardiomyocytes exhibited an improved contraction amplitude (>500%) on conductive hydrogels compared to cells cultured on Matrigel®. This was accompanied by increased cellular alignment, enhanced connexin 43 expression, and improved sarcomere organization suggesting maturation of the hiPSC-derived cardiomyocytes. Sarcomeric length of these cells increased from 1.3 to 1.7 µm. Moreover, 3D cell-laden engineered tissues exhibited enhanced calcium handling as well as positive response to external electrical and pharmaceutical stimulation. Collectively, our data indicate that our biohybrid hydrogels consisting of solubilized nanostructured pericardial matrix and electroconductive positively charged hydrazide-conjugated carbon nanotubes provide a promising material for stem cell-based cardiac tissue engineering.


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/citologia , Nanotubos de Carbono/química , Pericárdio/química , Tecidos Suporte/química , Biomarcadores/metabolismo , Cálcio/metabolismo , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Colágeno/química , Conexina 43/metabolismo , Combinação de Medicamentos , Condutividade Elétrica , Humanos , Laminina/química , Células-Tronco Mesenquimais/citologia , Tamanho da Partícula , Proteoglicanas/química
14.
Chemistry ; 25(51): 11847-11851, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31353639

RESUMO

The controlled self-assembly of porphyrin derivatives (TCPP, tetrakis(4-carboxyphenyl)porphyrin) within Fmoc-protected (Fmoc=9-Fluorenylmethyloxycarbonyl) dipeptide (Fmoc-TL-NH2 ) nanofibers is demonstrated. The biocatalytic co-assembly in aqueous medium generated an energy transfer hydrogel. Depending on the concentrations of porphyrin used, the resulting nanofibrous gels show two distinct regions of self-assembly behavior that is, integration of TCPP into nanostructures to produce two-component co-assembly fibers, or heterogeneous self-aggregation of TCPP within the self-assembled matrix observed at higher concentrations. The mode of assembly directly impacts on the energy transfer efficiency of these nanostructures. These results show that reversible biocatalytic co-assembly of structural and functional components enables fine-tuning of peptide/porphyrin energy transfer nanostructures.


Assuntos
Dipeptídeos/química , Peptídeos/química , Porfirinas/química , Biocatálise , Transferência de Energia , Hidrogéis/química , Nanofibras/química , Nanoestruturas/química
15.
Chem Commun (Camb) ; 55(49): 7093-7096, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31155632

RESUMO

A peptidic 'nanomillipede', consisting of a worm-like nanoscale 'body' and cysteine-terminated 'legs', was synthesized, tuned (with ultrasound) and utilized to crosslink the vinyl sulfone-modified dextran to form hybrid hydrogels with soft-tissue mimicking tuneable mechanical strength, self-healing property, and tuneable shear-thinning property, thereby indicating its potential use in tissue engineering and drug delivery.


Assuntos
Hidrogéis/síntese química , Nanopartículas/química , Peptídeos/química , Sistemas de Liberação de Medicamentos , Hidrogéis/química , Estrutura Molecular , Tamanho da Partícula , Peptídeos/síntese química , Propriedades de Superfície , Engenharia Tecidual
16.
Carbohydr Polym ; 219: 162-171, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151513

RESUMO

Rheological behaviors of microbial polysaccharides with different substituents in aqueous solutions have been systematically investigated. Both the saccharide side chains and acetyl substituents improve the gelation of welan gum (WG), diutan gum (DG) and gellan gum (GG) in pure water at 25 °C. For the polysaccharides with saccharide side chains (WG and DG), the relationship between the apparent viscosity and concentration conforms to the linear equation, while that of the polysaccharide with acetyl (GG) is exponential. More importantly, the roles of substituents on the stability of the molecular conformation of polysaccharides are significantly depended on the surrounding environment. Disaccharide side chains promote the stability of helical conformation and gel aggregates of GG at high temperature (85 °C) or in the presence of inorganic salts with the ionic strength of 2.0 mol L-1. The stability of gel structure containing acetyl (GG) shows higher temperature/salt sensitivity. Additionally, deacylated gellan gum (GG(d)) solutions transform into hydrogels in the presence of dodecyltrimethylammonium bromide (DTAB). This study will help to obtain a better understanding on the rheological properties of polysaccharides with respect to the conformation and applications.


Assuntos
Bactérias/metabolismo , Hidrogéis/química , Polissacarídeos Bacterianos/química , Reologia , Tensoativos/química , Ácido Acético/química , Concentração Osmolar , Sais/química , Soluções/química , Temperatura Ambiente , Viscosidade
17.
Environ Pollut ; 251: 945-951, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31234261

RESUMO

The removals of arsenic and selenium pollutants are always urgent desires for the water security. In this study, both sorption and catalysis strategies were combined for the effective removals of As(V) and Se(VI) over magnetic graphene oxide sheets (GOs)-oxidized carbon nanotubes (OCNTs) hydrogels. The sorption behavior facilitated the operation of catalysis reactions, meanwhile, the catalytic reduction promoted the release of occupied sorption sites and then restarted a new sorption-catalysis cycle. The synergic effect of sorption and catalysis realized 258.2 mg g-1 for As(V) enrichment capacity on MPG2T1, and ultra-fast sorption and catalysis equilibriums were identified within 9 min. In the case of Se(VI), a moderate enrichment performance was observed to be 46.2 mg g-1. Similarly, the ultra-fast sorption and reduction of Se(VI) were realized within 2 min. In the competition experiments, only SO42-, SO32-, and HPO42- showed interference for As(V) and Se(VI) removals. These results testified the superiority of the synergy effect of sorption and catalysis, and the feasibility of 3D magnetic GOs-OCNTs hydrogel in practical implementations.


Assuntos
Arsênico/química , Grafite/química , Nanotubos de Carbono/química , Selênio/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Catálise , Hidrogéis/química
18.
Int J Nanomedicine ; 14: 4211-4227, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239676

RESUMO

Background: Cisplatin is an extensively used anti-neoplastic agent for the treatment of various solid tumors. However, a high incidence of severe ototoxicity is accompanied by its use in the clinic. Currently, no drugs or therapeutic strategies have been approved for the treatment of cisplatin-induced ototoxicity by the FDA. Purpose: The purpose of this study was to investigate the otoprotective effects of dexamethasone (DEX)-loaded silk-polyethylene hydrogel (DEX-SILK) following round window membrane administration in the cisplatin-induced ototoxicity mouse model. Methods: The morphology, gelation kinetics, viscosity and secondary structure of the DEX-SILK hydrogel were analyzed. DEX concentration in the perilymph was tested at different time points following hydrogel injection on the RWM niche. Cultured cells (HEI-OC1), organ of Corti explants (C57/BL6, P0-2), and cisplatin-induced hearing loss mice model (C57/BL6) were used as in vitro and in vivo models for investigating the otoprotective effects of DEX-SILK hydrogel against cisplatin. Results: Encapsulation of DEX with a loading of 8% (w/v) did not significantly change the silk gelation time, and DEX was evenly distributed in the Silk-PEG hydrogel as visualized by scanning electron microscopy (SEM). The concentration of Silk majorly influenced DEX distribution, morphological characteristics, viscosity, and gelation time. The optimized DEX-SILK hydrogel (8% w/v loading, 15% silk concentration, 10 µl) was administered directly onto the RWM of the guinea pigs. The DEX concentration in the perilymph was maintained above 1 µg/ml for at least 21 days for the DEX-SILK, while it was maintained for less than 6 h in the control sample of free DEX. DEX-SILK (5-60 ng/ml) exhibited significant protective effects against cisplatin-induced cellular ototoxicity and notably reduced the production of reactive oxygen species (ROS). Eventually, pretreatment with DEX-SILK effectively preserved outer hair cells in the cultured organ of Corti explants and demonstrated significant hearing protection at 4, 8, and 16 kHz in the cisplatin-induced hearing loss mice as compared to the effects noted following pretreatment with DEX. Conclusion: These results demonstrated the clinical value of DEX-SILK for the therapy of cisplatin-induced ototoxicity.


Assuntos
Cisplatino/efeitos adversos , Dexametasona/farmacologia , Orelha/patologia , Hidrogéis/química , Injeções , Polietilenoglicóis/química , Seda/química , Animais , Materiais Biocompatíveis/efeitos adversos , Bombyx , Linhagem Celular , Cóclea/efeitos dos fármacos , Cóclea/patologia , Dexametasona/uso terapêutico , Modelos Animais de Doenças , Liberação Controlada de Fármacos , Cobaias , Perda Auditiva/induzido quimicamente , Perda Auditiva/tratamento farmacológico , Camundongos Endogâmicos C57BL , Substâncias Protetoras/farmacologia , Espécies Reativas de Oxigênio/metabolismo
19.
Anal Bioanal Chem ; 411(17): 3829-3838, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31172234

RESUMO

The rapid detection of bacterial strains has become a major topic thoroughly discussed across the biomedical field. Paired with the existence of nosocomial pathogen agents that imply extreme medical and financial challenges throughout diagnosis and treatment, the development of rapid and easy-to-use sensing devices has gained an increased amount of attention. Moreover, antibiotic resistance considered by World Health Organization as one of the "biggest threats to global health, food security, and development today" enables this topic as high priority. Pseudomonas aeruginosa, one of the most ubiquitous bacterial strains, has various quorum-sensing systems that are a direct cause of their virulence. One of them is represented by pyocyanin, a blue pigment with electroactive properties that is synthesized from early stages of bacterial colonization. Thus, the sensitive detection of this biomarker could enable a personalized and efficient therapy. It was achieved with the development of an electrochemical sensor based on a thermosensitive polymer, modified with Au/Ag nanoalloy for the rapid and accurate detection of pyocyanin, a virulence biomarker of Pseudomonas aeruginosa. The sensor displayed a linear range from 0.12 to 25 µM, and a limit of detection of 0.04 µM (signal/noise = 3). It was successfully tested in real samples spiked with the target analyte without any pretreatment other than a dilution step. The detection of pyocyanin with high recovery in whole blood in a time frame of 5-10 min from the moment of collection was performed with this electrochemical sensor. Graphical abstract.


Assuntos
Ligas/química , Ouro/química , Hidrogéis/química , Nanopartículas Metálicas/química , Piocianina/análise , Prata/química , Ágar/química , Artefatos , Biomarcadores/análise , Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Limite de Detecção , Sistemas Automatizados de Assistência Junto ao Leito , Pseudomonas aeruginosa/isolamento & purificação , Piocianina/sangue , Reprodutibilidade dos Testes , Temperatura Ambiente
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