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1.
Acta Crystallogr D Struct Biol ; 76(Pt 4): 366-374, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32254061

RESUMO

In this study, the first crystal structure of a novel crystal form of human insulin bound to meta-cresol in an acidic environment is reported. The combination of single-crystal and powder X-ray diffraction crystallography led to the detection of a previously unknown monoclinic phase (P21). The structure was identified from the powder patterns and was solved using single-crystal diffraction data at 2.2 Šresolution. The unit-cell parameters at pH 6.1 are a = 47.66, b = 70.36, c = 84.75 Å, ß = 105.21°. The structure consists of two insulin hexamers per asymmetric unit. The potential use of this insulin form in microcrystalline drugs is discussed.


Assuntos
Cresóis/química , Insulina/química , Cristalografia por Raios X , Humanos , Modelos Moleculares , Multimerização Proteica , Estrutura Quaternária de Proteína , Difração de Raios X
2.
Chemistry ; 26(11): 2456-2463, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31889346

RESUMO

Polyamine-salt aggregates (PSA) are biomimetic soft materials that have attracted great attention due to their straightforward fabrication methods, high drug-loading efficiencies, and attractive properties for pH-triggered release. Herein, a simple and fast multicomponent self-assembly process was used to construct cross-linked poly(allylamine hydrochloride)/phosphate PSAs (hydrodynamic diameter of 360 nm) containing glucose oxidase enzyme, as a glucose-responsive element, and human recombinant insulin, as a therapeutic agent for the treatment of diabetes mellitus (GI-PSA). The addition of increasing glucose concentrations promotes the release of insulin due to the disassembly of the GI-PSAs triggered by the catalytic in situ formation of gluconic acid. Under normoglycemia, the GI-PSA integrity remained intact for at least 24 h, whereas hyperglycemic conditions resulted in 100 % cargo release after 4 h of glucose addition. This entirely supramolecular strategy presents great potential for the construction of smart glucose-responsive delivery nanocarriers.


Assuntos
Sistemas de Liberação de Medicamentos , Glucose/química , Insulina/administração & dosagem , Insulina/química , Nanocápsulas/química , Poliaminas/química , Reagentes para Ligações Cruzadas/química , Diabetes Mellitus/tratamento farmacológico , Gluconatos/química , Humanos , Insulina/farmacologia
3.
Carbohydr Polym ; 229: 115506, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826394

RESUMO

In this study, insulin-loaded nanoparticles (NPs) were prepared via self-gelation method using chitosan and aqueous soluble snail mucin as natural polymers. Herein, mucins were ionically interacted with chitosan at different concentrations to obtained insulin-loaded NPs, labelled as A1 (1:1) (i.e., chitosan 2 % w/v + mucin 2 % w/v) and A2 (2:1) (chitosan 4 % w/v + mucin 2 % w/v), using poloxamer and poly vinyl alcohol as solid surfactant. Such formulation was selected to provide the necessary dynamics for the formation of the nanoparticles while maintaining the surface properties that will favor the encapsulation of insulin. Each system was characterized in terms of their particle size distribution, morphology, zeta potential, and polydispersity index. In vitro release of insulin was evaluated in acidic solution (pH 1.2) and phosphate buffer solution (pH 7.4), and the hypoglycaemic activity was evaluated in diabetes rats. The prepared insulin-loaded NPs displayed particles with relatively smooth surfaces and an average particle size of 479.6 and 504.1 nm for A1 and A2, respectively. Zeta potential and polydispersity index, ranged from 22.1 to 31.2 mV and 0.155-0.185, respectively. The encapsulating efficiency for the systems A1 and A2 were 88.6 and 92.5, respectively, and a self-sustained release of encapsulated insulin was observed for over a period of 8 h. In vivo studies revealed a pronounced hypoglycaemic effect in diabetic rats after peroral administration of the insulin-loaded NPs compared to the effect caused by free oral insulin solution. In addition, both the pharmacokinetic and toxicity results showed low plasma clearance of insulin and no signs of toxicity on the liver enzyme and cell viability, which suggested good biocompatibility of the NPs formulations. Overall, the formation of NPs of insulin with chitosan and snail mucin represents a potentially safe and promising approach to protect insulin and enhance its peroral delivery.


Assuntos
Quitosana/química , Diabetes Mellitus/tratamento farmacológico , Portadores de Fármacos/química , Insulina/química , Mucinas/química , Membrana Mucosa/química , Nanopartículas/química , Adesividade , Administração Oral , Animais , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/farmacologia , Liberação Controlada de Fármacos , Feminino , Insulina/administração & dosagem , Insulina/uso terapêutico , Masculino , Ratos , Ratos Wistar
4.
Biosens Bioelectron ; 147: 111767, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655384

RESUMO

Herein, a highly efficient electrochemiluminescence resonance energy transfer (ECL-RET) immunosensor was established for ultrasensitive insulin detection. Silver/silver orthophosphate/graphene oxide composites (Ag/Ag3PO4/GO) were prepared as sensing platform for capture-antibody (Ab1) incubation. Ag3PO4 is a novel ECL donor whose emission could be remarkably enhanced by the synergetic assistance of GO with Ag NPs. Notably, GO presented excellent electrical conductivity and ultrahigh specific surface area to improve the loading capacity Ab1 and Ag3PO4, and Ag NPs with fine biocompatibility and catalytic property could immobilize Ab1 via Ag-N bond and further hasten the electron transfer to catalyze the generation of SO4•- radicals for boosting the ECL emission of donor. To establish a new ECL-RET system, Pd@Au core-shell nanoflower was prepared as a suitable ECL acceptor which could immobilize the detection-antibody (Ab2). Due to the fine spectral overlap, Pd@Au nanoflower could significantly quench the ECL emission of Ag3PO4, causing distinct decreases in ECL intensity. The proposed ECL-RET immunosensor exhibited sensitive response to insulin in a linear range of 0.0001-80 ng/mL with a low detection limit of 0.02 pg/mL (S/N = 3), it not only provides a reliable tool for insulin detection in diagnostics of diabetes, but also lights up a new avenue for designing effective ECL-RET pairs in bioanalysis.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Grafite/química , Insulina/isolamento & purificação , Glucose Oxidase/química , Ouro/química , Humanos , Insulina/química , Limite de Detecção , Medições Luminescentes , Nanopartículas Metálicas/química , Fosfatos/química , Prata/química
5.
Talanta ; 207: 120321, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31594568

RESUMO

An optical aptasensor-based sensing platform for rapid insulin detection was fabricated. Aminated porous silica microparticles (PSiMPs) were synthesized via a facile mini-emulsion method to provide large surface area for covalent immobilization of insulin-binding DNA aptamer (IGA3) by glutaraldehyde cross-linking protocol. A Nickel-salphen type complex with piperidine side chain [Ni(II)-SP] was synthesized with a simple one-pot reaction, and functionalized as an optical label due to strong π-π interaction between aromatic carbons of G-quadruplex DNA aptamer and planar aromatic groups of Ni(II)-SP to form the immobilized IGA3-Ni(II)-SP complex, i.e. the dye-labeled aptamer, thereby bringing yellow colouration to the immobilized G-quartet plane. Optical characterization of aptasensor towards insulin binding was carried out with a fiber optic reflectance spectrophotometer. The maximum reflectance intensity of the immobilized IGA3-Ni(II)-SP complex at 656 nm decreased upon binding with insulin as aptasensor changed to brownish orange colouration in the background. This allows optical detection of insulin as the colour change of aptasensor is dependent on the insulin concentration. The linear detection range of the aptasensor is obtained from 10 to 50 µIU mL-1 (R2 = 0.9757), which conformed to the normal fasting insulin levels in human with a limit of detection (LOD) at 3.71 µIU mL-1. The aptasensor showed fast response time of 40 min and long shelf life stability of >3 weeks. Insulin detection using healthy human serums with informed consent provided by participants suggests the DNA aptamer biosensor was in good agreement with ELISA standard method using BIOMATIK Human INS (Insulin) ELISA Kit.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Técnicas Biossensoriais/instrumentação , Insulina/análise , Dispositivos Ópticos , Compostos Organometálicos/química , Fenilenodiaminas/química , Aptâmeros de Nucleotídeos/química , Ensaio de Imunoadsorção Enzimática , Humanos , Concentração de Íons de Hidrogênio , Insulina/sangue , Insulina/química , Insulina/metabolismo , Limite de Detecção , Porosidade , Bases de Schiff/química , Dióxido de Silício/química , Fatores de Tempo
6.
Int J Nanomedicine ; 14: 9127-9138, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819423

RESUMO

Purpose: This study evaluated the stereoisomeric effect of L- and D-penetratin-cell-penetrating peptides (CPPs)-incorporated insulin-loaded solid lipid nanoparticles (INS-SLNs) on the bioavailability (BA) of oral insulin (INS). Methods: Insulin-loaded solid nanoparticles, L-penetratin-INS-SLNs (LP-INS-SLNs), and D-penetratin-INS-SLNs (DP-INS-SLNs) were formulated by double emulsification. The developed SLNs were evaluated for particle size, zeta potential (ZP), and drug encapsulation and subjected to differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and evaluated for stability against enzymatic degradation in rat intestinal fluid. Finally, the SLNs were administered to rats to evaluate the BA of INS-SLNs that contained L- and D-penetratin. Results: The mean particle size, PDI, and ZP values of INS-SLNs, LP-INS-SLNs, and DP-INS-SLNs ranged from 618.5 to 973.0 nm, 0.227 to 0.734, and -17.0 to -23.7 mV, respectively. The encapsulation efficiency (%EE) and drug loading (%DL) of INS-SLNs, LP-INS-SLNs, and DP-INS-SLNs ranged from 59.03% to 67.42% and from 1.62% to 1.82%, respectively. Differential scanning calorimetry and FTIR analyses indicated that INS was successfully encapsulated in SLNs. Enzymatic degradation of DP-INS-SLNs was slower in intestinal fluid, and the half-life (t1/2) was significantly prolonged, compared to all other SLNs. The pharmacological availability (PA) and BA of orally administered LP-INS-SLNs, which were the most effective SLNs, were 13.1% and 15.7% relative to s.c. administration, respectively. Conclusion: Penetratin stereochemistry significantly impacted oral BA of INS-SLNs, which are promising carriers for oral INS administration.


Assuntos
Peptídeos Penetradores de Células/administração & dosagem , Peptídeos Penetradores de Células/química , Insulina/química , Lipídeos/química , Nanopartículas/química , Administração Oral , Animais , Disponibilidade Biológica , Glicemia/análise , Varredura Diferencial de Calorimetria , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Humanos , Insulina/administração & dosagem , Insulina/sangue , Insulina/farmacocinética , Masculino , Tamanho da Partícula , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Chem Commun (Camb) ; 55(83): 12507-12510, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31576386

RESUMO

Charge reduction and neutralization of electro-sprayed peptides are realized by selective gas-phase photocleavage of tailored covalent tags. The concept is demonstrated with four model peptides in positive and negative ion modes and tagged insulin as the largest construct.


Assuntos
Insulina/química , Peptídeos/química , Vácuo , Íons/química , Estrutura Molecular , Processos Fotoquímicos
8.
Molecules ; 24(20)2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31618999

RESUMO

In this study, N-methylated analogs of hot-spots of insulin were designed and synthesized, in the expectation that they would inhibit the aggregation of both insulin hot-spots and the entire hormone. Synthesis of insulin "amyloidogenic" analogs containing N-methylated amino acid residues was performed by microwave-assisted solid phase according to the Fmoc/tert-Bu strategy. As a coupling reagent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium toluene-4-sulfonate (DMT/NMM/TosO-) was used. Three independent methods were applied in aggregation studies of the complexes of insulin with its N-methylated peptides. Additionally, circular dichroism (CD) measurements were used to confirm that aggregation processes did not occur in the presence of the N-methylated analogs of hot-spot insulin fragments, and that insulin retains its native conformation. Of the seven N-methylated analogs of the A- and B-chain hot-spots of insulin, six inhibited insulin aggregation (peptides 1 and 3-7). All tested peptides were found to have a lower ability to inhibit the aggregation of insulin hot-spots compared to the capability to inhibit native hormone aggregation.


Assuntos
Aminoácidos/química , Hormônios/química , Insulina/química , Sequência de Aminoácidos , Hormônios/metabolismo , Insulina/metabolismo , Metilação , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Agregados Proteicos
9.
Int J Mol Sci ; 20(18)2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31509943

RESUMO

Insulin-degrading enzyme (IDE) was applied to catalyze hydrolysis of Nociceptin/Orphanin 1-16 (OFQ/N) to show the involvement of the enzyme in degradation of neuropeptides engaged in pain transmission. Moreover, IDE degradative action towards insulin (Ins) was inhibited by the OFQ/N fragments, suggesting a possible regulatory mechanism in the central nervous system. It has been found that OFQ/N and Ins affect each other degradation by IDE, although in a different manner. Indeed, while the digestion of OFQ/N is significantly affected by the presence of Ins, the kinetic profile of the Ins hydrolysis is not affected by the presence of OFQ/N. However, the main hydrolytic fragments of OFQ/N produced by IDE exert inhibitory activity towards the IDE-mediated Ins degradation. Here, we present the results indicating that, besides Ins, IDE cleaves neuropeptides and their released fragments act as inhibitors of IDE activity toward Ins. Having in mind that IDE is present in the brain, which also contains Ins receptors, it cannot be excluded that this enzyme indirectly participates in neural communication of pain signals and that neuropeptides involved in pain transmission may contribute to the regulation of IDE activity. Finally, preliminary results on the metabolism of OFQ/N, carried out in the rat spinal cord homogenate in the presence of various inhibitors specific for different classes of proteases, show that OFQ/N proteolysis in rat spinal cord could be due, besides IDE, also to a cysteine protease not yet identified.


Assuntos
Insulina/metabolismo , Insulisina/metabolismo , Peptídeos Opioides/metabolismo , Medula Espinal/metabolismo , Sequência de Aminoácidos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Cromatografia Líquida/métodos , Insulina/química , Insulisina/antagonistas & inibidores , Espectrometria de Massas/métodos , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Neuropeptídeos/farmacologia , Peptídeos Opioides/química , Dor/prevenção & controle , Medição da Dor/métodos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Ratos , Receptor de Insulina/metabolismo , Medula Espinal/efeitos dos fármacos
10.
Elife ; 82019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31436533

RESUMO

Insulin signaling controls metabolic homeostasis. Here, we report the cryo-EM structure of full-length insulin receptor (IR) and insulin complex in the active state. This structure unexpectedly reveals that maximally four insulins can bind the 'T'-shaped IR dimer at four distinct sites related by 2-fold symmetry. Insulins 1 and 1' bind to sites 1 and 1', formed by L1 of one IR protomer and α-CT and FnIII-1 of the other. Insulins 2 and 2' bind to sites 2 and 2' on FnIII-1 of each protomer. Mutagenesis and cellular assays show that both sites 1 and 2 are required for optimal insulin binding and IR activation. We further identify a homotypic FnIII-2-FnIII-2 interaction in mediating the dimerization of membrane proximal domains in the active IR dimer. Our results indicate that binding of multiple insulins at two distinct types of sites disrupts the autoinhibited apo-IR dimer and stabilizes the active dimer.


Assuntos
Ativação Enzimática , Insulina/química , Insulina/metabolismo , Receptor de Insulina/química , Receptor de Insulina/metabolismo , Microscopia Crioeletrônica , Humanos , Ligação Proteica , Conformação Proteica , Multimerização Proteica
11.
Int J Pharm ; 569: 118584, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31376466

RESUMO

This study aimed to develop biocompatible deep eutectic solvents (DESs) as carriers for improving the nasal delivery of insulin. The DES was prepared from malic acid and choline chloride broadly used in foods, drugs, or cosmetics as biocompatible additives. The DES of choline chloride and malic acid (CM-DES) demonstrated lower melting point (-59.1 °C) and higher viscosity (120,000 cP) compared with hydrogels based on sodium carboxyl methyl cellulose (CMC-Na). The conformational structure of insulin does not change in CM-DES as characterized by circular dichroism. The in vitro results showed that CM-DES dissociated gradually but did not disintegrate immediately upon contact with water. CM-DES was able to improve the hypoglycemic effect of insulin significantly at different doses compared with hydrogels or solutions of insulin, which could be ascribed to facilitated penetration of insulin across the nasal epithelia by CM-DES. The hypoglycemic effect of CM-DES loading insulin at a dose of 25 IU/kg was similar to that of subcutaneous insulin at 1 IU/kg. In addition, no evident toxicity to nasal epithelia was observed after nasal administration to rats for seven consecutive days. In conclusion, CM-DES showed promising potential in enhancing the hypoglycemic effect of insulin via the nasal route.


Assuntos
Colina/administração & dosagem , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Malatos/administração & dosagem , Solventes/administração & dosagem , Administração Intranasal , Animais , Glicemia/efeitos dos fármacos , Colina/química , Liberação Controlada de Fármacos , Hidrogéis/administração & dosagem , Hidrogéis/química , Hipoglicemiantes/química , Insulina/química , Malatos/química , Mucosa Nasal/metabolismo , Ratos , Ratos Sprague-Dawley , Solventes/química , Água/química
12.
Biophys Chem ; 253: 106226, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31376619

RESUMO

The quaternary structures of insulin glargine and glulisine under formulation conditions and upon dilution using placebo or water were investigated using synchrotron small-angle X-ray scattering. Our results revealed that insulin glulisine in Apidra® is predominantly hexameric in solution with significant fractions of dodecamers and monomers. Upon dilution with placebo, this equilibrium shifts towards monomers. Insulin glargine in Lantus® and Toujeo® is present in a stable hexamer/dimer equilibrium, which is hardly affected by dilution with water down to 1 mg/ml insulin concentration. The results provide exclusive insight into the quaternary structure and thus the association/dissociation properties of the two insulin analogues in marketed formulations.


Assuntos
Hipoglicemiantes/química , Insulina Glargina/química , Insulina/análogos & derivados , Humanos , Insulina/química , Modelos Moleculares , Estrutura Quaternária de Proteína
13.
Eur J Pharm Biopharm ; 143: 98-105, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31425857

RESUMO

Oral delivery of peptides is challenging due to their low uptake through the small intestinal epithelium. Tight junctions, connecting the enterocytes, impede permeability, often necessitating the use of permeation enhancers in the formulation. Loading of peptide and permeation enhancer into micro-scale devices, such as microcontainers, can potentially confine the effective absorptive area through unidirectional release and thereby enhance absorption. This concept is investigated by in vitro permeation studies of insulin across Caco-2 cell and Caco-2/HT29-MTX-E12 co-culture monolayers mimicking the intestinal absorption barrier. The importance of proximity between the microcontainers and the barrier is assessed, by keeping the amounts of insulin and sodium caprate fixed throughout all experiments, while collectively orienting the unidirectional release towards the cell monolayers. Increasing the distance is observed to have a negative effect on insulin permeation matching a one-phase exponential decay function, while no difference in insulin transport is observed between Caco-2 and co-culture monolayers. Although there are no signs of cytotoxicity caused by the microcontainer material, reversible cell deterioration, as a consequence of high local concentrations of sodium caprate, becomes evident upon qualitative assessment of the cell monolayers. These results both suggest a potential of increasing oral bioavailability of peptides by the use of microcontainers, while simultaneously visualising the ability of regaining monolayer integrity upon local permeation enhancer induced toxicity.


Assuntos
Insulina/administração & dosagem , Insulina/química , Permeabilidade/efeitos dos fármacos , Administração Oral , Disponibilidade Biológica , Transporte Biológico/efeitos dos fármacos , Células CACO-2 , Linhagem Celular Tumoral , Técnicas de Cocultura/métodos , Humanos , Absorção Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Peptídeos/administração & dosagem , Peptídeos/química , Junções Íntimas/metabolismo
14.
AAPS PharmSciTech ; 20(7): 298, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31456109

RESUMO

We aimed to investigate the absorption-enhancing effect (AEE) of caproyl-modified G2 PAMAM dendrimer (G2-AC) on peptide and protein drugs via the pulmonary route. In this study, G2 PAMAM dendrimer conjugates modified with caproic acid was synthesized, the pulmonary absorption of insulin as models with or without G2-AC were evaluated. The results indicated that G2-AC6 exhibited a greatest AEE for insulin in various caproylation levels of G2-AC. G2-AC6 could significantly enhance the absorption of insulin, and the AEE of G2-AC6 was concentration-dependent. In toxicity tests, G2-AC6 displayed no measurable cytotoxicity to the pulmonary membranes over a concentration range from 0.1% (w/v) to 1.0% (w/v). Measurements of the TEER and permeability showed that G2-AC6 significantly reduced the TEER value of CF and increased its Papp value. The results suggested that G2-AC6 could cross epithelial cells by means of a combination of paracellular and transcellular pathways. These findings suggested G2-AC6 at lower concentrations (below 1.0%, w/v) might be promising absorption enhancers for increasing the pulmonary absorption of peptide and protein drugs.


Assuntos
Materiais Biocompatíveis/metabolismo , Dendrímeros/metabolismo , Insulina/metabolismo , Nanopartículas/metabolismo , Absorção pelo Trato Respiratório/fisiologia , Animais , Materiais Biocompatíveis/administração & dosagem , Materiais Biocompatíveis/química , Dendrímeros/administração & dosagem , Dendrímeros/química , Insulina/administração & dosagem , Insulina/química , Masculino , Nanopartículas/administração & dosagem , Nanopartículas/química , Permeabilidade/efeitos dos fármacos , Ratos , Ratos Wistar , Absorção pelo Trato Respiratório/efeitos dos fármacos
15.
Biophys Chem ; 253: 106231, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31377658

RESUMO

Amyloid fibrils have well known pathological implications as well as a clear functional role in different biological systems due to their peculiar structural and mechanical properties. We had previously shown the appearance of elastic properties during the formation of a gel of insulin amyloid fibrils. Here, we study the morphological, rheological and dynamical behaviour of this jammed system. We observe different non-diffusive relaxation processes over a wide length and time interval, suggesting the formation of an elastic transient network of fibrils, and evidencing the structural heterogeneity of the gel matrix and the peculiarity of this potentially new material.


Assuntos
Amiloide/química , Insulina/química , Termodinâmica , Animais , Fenômenos Biomecânicos , Bovinos , Tamanho da Partícula , Propriedades de Superfície
16.
Drug Deliv ; 26(1): 650-660, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31257946

RESUMO

Purpose: With the increase of population aging and the proportion of overweight and obese, a growing number of people are suffering from diabetes. Insulin (INS) as the most widely used hypoglycemic agent was always chosen as the most effective treatment method of diabetes. In this study, fumaryl diketopiperazine (FDKP) was used as a carrier for the pulmonary delivery of insulin. Patients and methods: The INS-loaded FDKP microspheres (INS@FDKP-MPs) were prepared by spray drying and physicochemical properties (drug loading, particle size, flowability, moisture content, morphology, and crystalline state) were further investigated. Pharmacodynamics was investigated on diabetic model rats administrated by intratracheal insufflation. Results: The INS-loaded FDKP microspheres show satisfied flowability and in vitro deposition with FPF 50.2% and MMAD 3.45 ± 0.13 µm, and the blood glucose level was significantly decreased. Moreover, no inflammatory reaction was observed during the safety study. Conclusion: To sum up, the aim was to develop a non-injection system for insulin, INS@FDKP-MPs powder inhalation with high dose, low toxicity, and good lung deposition inhalation could rapidly decrease the blood glucose level without immune stimulation, which shows remarkably potential on diabetes treatment by pulmonary delivery route.


Assuntos
Dicetopiperazinas/administração & dosagem , Dicetopiperazinas/química , Insulina/administração & dosagem , Insulina/química , Pós/administração & dosagem , Pós/química , Administração por Inalação , Animais , Sistemas de Liberação de Medicamentos/métodos , Inaladores de Pó Seco/métodos , Hipoglicemiantes/química , Masculino , Microesferas , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley
17.
Talanta ; 204: 285-293, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357295

RESUMO

To obtain sensitive analytical detection methods, many unique materials have been developed and made them promising candidates for biosensing. In this study, a type of core-shell gold nanorods, GNR@Au2S/AuAgS/CuS, possessing peroxidase-like activity was prepared in a simple, facile manner. A colorimetric strategy for detection of blood glucose, insulin and differentiating type 1 and type 2 diabetes was developed based on the unique GNR@Au2S/AuAgS/CuS. The sensitive colorimetric approach for detection of glucose in the dynamic range of 2.5-200 µM was first established based on the catalytic performance of GNR@Au2S/AuAgS/CuS. Meanwhile, the catalytic activity of the peroxidase-like GNR@Au2S/AuAgS/CuS can be regulated by introducing the high affinity and specific reaction between DNA aptamer and insulin on the surface of GNR@Au2S/AuAgS/CuS, which allows the colorimetric assay to be extended to the detection of insulin, and a quantitative analysis of insulin based on the specific recognition can be implemented at the range from 0.014 to 1.08 µU/mL. Furthermore, colorimetric approach coupling peroxidase-like performance and specific recognition on the surface of GNR@Au2S/AuAgS/CuS nanoparticles was developed to measure glucose/insulin ratio and directly differentiate type 1 and type 2 diabetes mellitus. Practical human serum samples were tested and only the glucose/insulin ratio greater than 2.2 (µU/mL) may lead to the appearance of color change. The coupling of this different bioassay on the same nanoparticles reflects the versatility and integration characteristics of the colorimetric assay and is highly promising for improving diabetes management.


Assuntos
Glicemia/análise , Colorimetria/métodos , Insulina/sangue , Nanotubos/química , Animais , Aptâmeros de Nucleotídeos/química , Benzidinas/química , Materiais Biomiméticos/química , Glicemia/química , DNA/química , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 2/diagnóstico , Diagnóstico Diferencial , Glucose Oxidase/química , Ouro/química , Humanos , Peróxido de Hidrogênio , Insulina/química , Peroxidase/química , Suínos
18.
J Photochem Photobiol B ; 197: 111541, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31272033

RESUMO

Here, we report the novel fabrication of ZnO nanoparticles using the Costus igneus leaf extract. Gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance (1H NMR) spectroscopy to determine the bioactive components present in the plant extract. The synthesis of Ci-ZnO NPs (C. igneus- coated zinc oxide nanoparticles) was accomplished using a cost-effective and simple technique. Ci-ZnO NPs were specified using UV-visible spectroscopy, FTIR, XRD, and TEM. Ci-ZnO NPs was authenticated by UV-Vis and exhibited a peak at 365 nm. The XRD spectra proved the crystalline character of the Ci-ZnO NPs synthesized as hexagonal wurtzite. The FTIR spectrum illustrated the presence of possible functional groups present in Ci-ZnO NPs. The TEM micrograph showed evidence of the presence of a hexagonal organization with a size of 26.55 nm typical of Ci-ZnO NPs. The α-amylase and α-glucosidase inhibition assays demonstrated antidiabetic activity of Ci-ZnO NPs (74 % and 82 %, respectively), and the DPPH [2,2-diphenyl-1-picrylhydrazyl hydrate] assay demonstrated the antioxidant activity of the nanoparticles (75%) at a concentration of 100 µg/ml. The Ci-ZnO NPs exhibited promising antibacterial and biofilm inhibition activity against the pathogenic bacteria Streptococcus mutans, Lysinibacillus fusiformis, Proteus vulgaris, and Vibrio parahaemolyticus. Additionally, the Ci-ZnO NPs showed biocompatibility with mammalian RBCs with minimum hemolytic activity (0.633 % ±â€¯0.005 %) at a concentration of 200 µg/ml.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/química , Biofilmes/efeitos dos fármacos , Nanopartículas Metálicas/química , Extratos Vegetais/química , Óxido de Zinco/química , Antibacterianos/síntese química , Antibacterianos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Costus/química , Costus/metabolismo , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/fisiologia , Química Verde , Hemólise/efeitos dos fármacos , Humanos , Insulina/química , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
19.
Nat Commun ; 10(1): 3312, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31346174

RESUMO

Compromised function of insulin-secreting pancreatic ß cells is central to the development and progression of Type 2 Diabetes (T2D). However, the mechanisms underlying ß cell failure remain incompletely understood. Here, we report that metabolic stress markedly enhances macroautophagy-independent lysosomal degradation of nascent insulin granules. In different model systems of diabetes including of human origin, stress-induced nascent granule degradation (SINGD) contributes to loss of insulin along with mammalian/mechanistic Target of Rapamycin (mTOR)-dependent suppression of macroautophagy. Expression of Protein Kinase D (PKD), a negative regulator of SINGD, is reduced in diabetic ß cells. Pharmacological activation of PKD counters SINGD and delays the onset of T2D. Conversely, inhibition of PKD exacerbates SINGD, mitigates insulin secretion and accelerates diabetes. Finally, reduced levels of lysosomal tetraspanin CD63 prevent SINGD, leading to increased insulin secretion. Overall, our findings implicate aberrant SINGD in the pathogenesis of diabetes and suggest new therapeutic strategies to prevent ß cell failure.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Lisossomos/metabolismo , Animais , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatologia , Humanos , Insulina/química , Secreção de Insulina , Células Secretoras de Insulina/citologia , Masculino , Camundongos Endogâmicos C57BL , Proteína Quinase C/genética , Proteína Quinase C/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
20.
Int J Biol Macromol ; 138: 89-96, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31302129

RESUMO

Studies of amyloid proteins have gradually become a hot topic. Nevertheless, very few effective drugs and treatments is available to cope with amyloid diseases. New molecules that can inhibit the protein fibrillation are highly anticipated. Insulin is one of the popular amyloid protein research models. On the other hand, resazurin and resorufin are widely known as a redox pair. We describes here an unexpected finding that resazurin plays a role in modulating insulin fibrillation, whereas resorufin doesn't. We hypothesize that the positively charged insulin at low pH can combine with the negatively charged resazurin due to electrostatic interaction, through which resazurin inhibited the process of insulin fibrillation. This effect was characterized and verified by using various biochemical, spectroscopic and imaging tools. This inhibition of this biocompatible dye can be achieved at various stages of fibrillation, suggesting the toxicity of the protein fibrils can be eliminated by using resazurin.


Assuntos
Insulina/química , Insulina/metabolismo , Agregados Proteicos , Escherichia coli/efeitos dos fármacos , Modelos Moleculares , Oxazinas/química , Oxazinas/metabolismo , Oxazinas/toxicidade , Oxirredução , Conformação Proteica , Xantenos/química , Xantenos/metabolismo , Xantenos/toxicidade
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