RESUMO
The objective of present study is to explore whether polysaccharide could be a crystal growth inhibitor in poorly soluble antitumor drug Ibrutinib (IBR) formulation. In this work, small molecular ligands (amino or organic acids) in co-amorphous system (CAS) were preliminarily screened. A polysaccharide, microcrystalline cellulose (MCC) was selected to stabilize amorphous drug and enhance pharmacokinetic properties. Fourier-transform infrared, Raman, and X-ray photoelectron spectroscopy confirmed the ionic interaction of the ternary IBR formulation. Moreover, the biosafety of the ternary formulation was the same as that of IBR while the in vitro performance advantage of the ternary formulation was converted into higher bioavailability in vivo experiments. Overall, MCC as an effective crystal growth inhibitor in the novel ternary IBR formulation is a promising approach to improve the dissolution rate of crystalline drugs and the stability of amorphous drugs, as well as providing a theoretical basis for clinical applications.
Assuntos
Celulose/química , Pirazóis/química , Pirimidinas/química , Adenina/análogos & derivados , Animais , Disponibilidade Biológica , Linhagem Celular Tumoral , Fenômenos Químicos , Cristalização , Composição de Medicamentos , Humanos , Masculino , Piperidinas , Pirazóis/farmacocinética , Pirazóis/farmacologia , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , RatosRESUMO
In this study, a novel Bruton's tyrosine kinase inhibitor, ibrutinib, was loaded into chitosan/sulfobutylether-ß-cyclodextrin nanoparticles (NPs). NPs have gained high loading efficiency for the hydrophobic drug due to the inclusion of cyclodextrin. Ibrutinib-loaded NPs with an average diameter of 277.9 nm and ζ-potential of +19.1 mV were obtained after regulating several influencing factors. Electrostatic reaction between mucin and NPs indicated that the NPs had a mucoadhesive property. Kinase catalytic phosphorylation was monitored by capillary zone electrophoresis and found that chitosan/sulfobutylether-ß-cyclodextrin NPs did not weaken ibrutinib activity on the target kinase. In vitro drug release studies revealed that ibrutinib-loaded NPs exhibited a significantly slower gastric-release rate. This study applied a feasible nanocarrier for ibrutinib delivery, and the potential nanoformulation maintains drug activity and shows a sustained release property. These outcomes are helpful for the formulation exploitation of tyrosine kinase inhibitors.
Assuntos
Quitosana , Nanopartículas , Adenina/análogos & derivados , Portadores de Fármacos , Tamanho da Partícula , Piperidinas , Inibidores de Proteínas Quinases , beta-CiclodextrinasRESUMO
Empagliflozin is an oral sodium glucose co-transporter-2 inhibitor for type 2 diabetes mellitus. The interaction between empagliflozin and human serum albumin (HSA) was investigated experimentally and theoretically. Fluorescence quenching and time-resolved fluorescence spectroscopy indicated that the quenching mechanism of empagliflozin and HSA was dynamic and that the effective binding constant at body temperature was 3.495 × 103 M-1. Thermodynamic parameters showed that hydrophobic forces were the major binding force in the interaction between empagliflozin and HSA. Circular dichroism, Fourier transform infrared, and 3 D fluorescence spectroscopy revealed that empagliflozin showed a slight change in secondary structure without changing the basic carbon framework of HSA. Site marker displacement experiments revealed that empagliflozin bound to site I of HSA, which was supported by molecular docking. Molecular dynamic simulations indicated that empagliflozin could bind to HSA stably. This study provided insights into the binding mechanism between empagliflozin and HSA.Communicated by Ramaswamy H. Sarma.
Assuntos
Compostos Benzidrílicos , Glucosídeos , Inibidores do Transportador 2 de Sódio-Glicose , Simportadores , Sítios de Ligação , Dicroísmo Circular , Diabetes Mellitus Tipo 2 , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Albumina Sérica Humana/metabolismo , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , TermodinâmicaRESUMO
The presence of dyes in a water system has potential adverse effects on the ecological environment. The conventional cyclodextrin (CD) polymer only has CD cavities as adsorption sites and exhibits slow adsorption for dye removal. In this study, we designed a novel carboxymethyl ß-CD polymer (ß-CDP-COOH). The structural properties of ß-CDP-COOH were characterized as an irregular cross-linked polymer with negative surface charge, and the introduction of carboxymethyl groups greatly enhanced the adsorption ability of the ß-CD polymer to basic fuchsin (BF). The maximum removal efficiency of ß-CDP-COOH (96%) could be achieved within 1 min, whereas that of conventional ß-CD polymer (70%) was achieved after 50 min. The adsorption mechanism revealed that the adsorption behavior of ß-CDP-COOH could be effectively fitted with the pseudo-second-order kinetic model and Langmuir isotherm. Both CD cavities and carboxymethyl groups were effective adsorption sites, so ß-CDP-COOH had an advantage in adsorption capacity over the conventional ß-CD polymer. This study indicated that ß-CDP-COOH is a potential highly efficient adsorbent for the removal of cationic dye contaminants.
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Telaprevir (TVR) is typically a poorly soluble drug with an extremely low bioavailability of 1.7%. Polymorph modifications cannot improve the solubility of TVR because it only has a single unsolvated crystalline form. Co-crystals also provide limited bioavailability enhancement for TVR. Thus, in this study, we increased the solubility and dissolution rate of TVR through formulations of TVR-polymer solid dispersions. Three solid dispersions of TVR were successfully prepared by co-milling with polyvinylpyrrolidone K30 (PVP), polyethylene glycol 6000, and hydroxypropyl methylcellulose (HPMC), which were characterized by different techniques. According to X-ray powder diffraction and differential scanning calorimetry results, TVR presented in amorphous form in all solid dispersions. The fourier transform infrared spectra results indicated that TVR may connect with polymers through the N-H···O or O-H···O hydrogen bonds, which were verified by molecular docking. TVR-PVP and TVR-HPMC displayed a good stability at conventional RH levels, and their thermostabilities were better than those of milled TVR. Among the three solid dispersions, TVR-HPMC showed significant solubility and dissolution rate advantages in different media. Moreover, TVR-HPMC displayed the same anticancer efficacy with crystalline TVR and presented no toxic side effects to normal liver cells. Thus, TVR-HPMC showed potential application value.
Assuntos
Fenômenos Químicos , Composição de Medicamentos/métodos , Oligopeptídeos/farmacologia , Varredura Diferencial de Calorimetria , Morte Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Conformação Molecular , Simulação de Acoplamento Molecular , Oligopeptídeos/química , Polímeros/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios XRESUMO
The study mainly aimed to improve the aqueous solubility of Balofloxacin (BLFX) by preparing the inclusion complexes (ICs) of BLFX with cyclodextrins (CDs). In this study, ICs in solid state were obtained by using beta-CD (ß-CD), 2-hydroxypropyl-ß-CD (HP-ß-CD), 2, 6-dimethyl-ß-CD (DM-ß-CD) through a freeze-drying technique. The formation of ICs was confirmed through Fourier-transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffraction, nuclear magnetic resonance, and scanning electron microscopy. Results demonstrated that the water solubility and dissolution rates of three ICs were distinctly improved than that of parent BLFX. Bacteriostatic experiment manifested that the antibacterial effect of BLFX was not inhibited after encapsulation in CDs. The damage of BLFX to kidney and liver cells was reduced. Consequently, successful preparation of the ICs of BLFX with CDs provided possibility for devising new dosage form of BLFX, which held great promise for further applications in clinical fields.
Assuntos
Fluoroquinolonas/química , beta-Ciclodextrinas/química , Varredura Diferencial de Calorimetria , Composição de Medicamentos , Liofilização/métodos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Pós , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios XRESUMO
Nanoscale metal-organic frameworks (NMOFs) have attracted considerable attention for controlled drug delivery. However, the interaction between nanoparticles and the biological macromolecules of physiological system must be valued because the formed protein corona will endow NMOFs with new biorecognition properties. In this study, we carried out detailed protein adsorption studies in vitro and cell uptake tests of HeLa cells for nanospherical Uio66 and nanooctahedral Uio67. Uio67 with higher binding constants to human serum albumin needed to combine more protein molecules to achieve colloidal stability state than that needed by Uio66, and this phenomenon led Uio67 to aggregate under the same incubation condition due to the formation of a single-layer protein. Uio67 also induced an evident conformation change in protein to stabilize the combination. In particular, the cell uptake efficiencies of the two systems showed a significant thickness dependence on the protein corona. When samples incubated in 10% fetal bovine serum (FBS), the intracellular rate was the highest for both systems, but the rate was not proportional to the FBS concentration. Results of this work are important to the development of the considerable potential NMOFs-based medicals and also provide additional insight into protein corona.
Assuntos
Comunicação Celular/fisiologia , Estruturas Metalorgânicas/química , Nanopartículas/química , Coroa de Proteína/química , Coroa de Proteína/metabolismo , Adsorção , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Células HeLa , Humanos , Tamanho da Partícula , Ligação Proteica , Albumina Sérica Humana/química , Albumina Sérica Humana/metabolismoRESUMO
Ertugliflozin is a potent and selective inhibitor of sodium-dependent glucose cotransporters 2 (SGLT2) and used as a monotherapy to improve glycemic control in adult patients with type 2 diabetes. In this study, ertugliflozin binding to human serum albumin (HSA) was investigated by multispectroscopic and computer simulations. The fluorescence spectra demonstrated that the quenching mechanism of ertugliflozin and HSA was static quenching. Thermodynamic parameters indicated that hydrogen bonding and van der Waals forces played a key role in the binding. Fluorescence competition experiments and molecular docking revealed that ertugliflozin bound to HSA sites II. In three-dimensional fluorescence, circular dichroism spectroscopy, and molecular dynamics simulation, ertugliflozin did not affect the basic skeleton structure of HSA but slightly increased the α-helical structure content and changed the microenvironment around amino acid residues. Results provide valuable information on the basis of the interaction of ertugliflozin with HSA.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/metabolismo , Albumina Sérica Humana/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose/metabolismo , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica/efeitos dos fármacos , Albumina Sérica Humana/química , TermodinâmicaRESUMO
The binding properties between γ-lactone essences and HSA were investigated to explore interactional mechanism and influence of ligand side chains on binding via computer simulations, microscopy, and multiple-spectroscopies. Docking and molecular dynamics presented protein recognition mode with low fluctuations. NMR analysis revealed that the lactone ring of ligands was the main group bound to HSA. UV-vis and lifetime results revealed that the combination was static quenching mechanism with binding constants of 102-103â¯L/mol. FTIR and CD spectra showed conformational changes in the protein secondary structure induced by ligands. Side chains affect the binding process through steric hindrance and hydrophobicity. AFM images showed the four compounds caused different effects on molecular size of HSA. In conclusion, the binding ability and the protein secondary structure changes had a positive correlation with the length of side chain. These studies are beneficial for understanding the safety and biological action of γ-lactone essences.
Assuntos
Lactonas/química , Albumina Sérica Humana/química , Albumina Sérica Humana/metabolismo , Sítios de Ligação , Dicroísmo Circular , Humanos , Interações Hidrofóbicas e Hidrofílicas , Lactonas/metabolismo , Ligantes , Espectroscopia de Ressonância Magnética , Microscopia de Força Atômica , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Estrutura Secundária de Proteína , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The interaction mechanism and binding mode of capecitabine with ctDNA was extensively investigated using docking and molecular dynamics simulations, fluorescence and circular dichroism (CD) spectroscopy, DNA thermal denaturation studies, and viscosity measurements. The possible binding mode and acting forces on the combination between capecitabine and DNA had been predicted through molecular simulation. Results indicated that capecitabine could relatively locate stably in the G-C base-pairs-rich DNA minor groove by hydrogen bond and several weaker nonbonding forces. Fluorescence spectroscopy and fluorescence lifetime measurements confirmed that the quenching was static caused by ground state complex formation. This phenomenon indicated the formation of a complex between capecitabine and ctDNA. Fluorescence data showed that the binding constants of the complex were approximately 2 × 104 M-1. Calculated thermodynamic parameters suggested that hydrogen bond was the main force during binding, which were consistent with theoretical results. Moreover, CD spectroscopy, DNA melting studies, and viscosity measurements corroborated a groove binding mode of capecitabine with ctDNA. This binding had no effect on B-DNA conformation.
Assuntos
Antimetabólitos Antineoplásicos/química , Capecitabina/química , DNA/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Algoritmos , Animais , Antimetabólitos Antineoplásicos/farmacologia , Sítios de Ligação , Capecitabina/farmacologia , Bovinos , Modelos Teóricos , Estrutura Molecular , Conformação de Ácido Nucleico , Reprodutibilidade dos Testes , Reologia , Análise EspectralRESUMO
Interaction between ulipristal acetate (UPA) and human serum albumin (HSA) was investigated in simulated physiological environment using multi-spectroscopic and computational methods. Fluorescence experiments showed that the quenching mechanism was static quenching, which was confirmed by the time-resolved fluorescence. Binding constants (Ka) were found to be 1 × 105 L mol-1, and fluorescence data showed one binding site. Thermodynamic constants suggested the binding process was mainly controlled by electrostatic interactions. Results from the competition experiments indicated that UPA bound to site I of HSA. Fourier transform infrared spectra, circular dichroism spectra, synchronous fluorescence spectra, and 3D fluorescence indicated that UPA can induce conformation change in the HSA. The content of α-helix and ß-sheet increased, while ß-turn decreased. Hydrophobicity around the tryptophan residues declined, whereas its polarity increased. Molecular docking results were consistent with the experimental results. Results suggested that UPA located at the hydrophobic cavity site I of HSA, and hydrophobic force played the key role in the binding process. Moreover, molecular dynamics simulation was performed to determine the stability of free HSA and HSA-UPA system. Results indicated that UPA can stabilize HSA to a certain degree and enhance the flexibility of residues around site I. Communicated by Ramaswamy H. Sarma.
Assuntos
Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Norpregnadienos/metabolismo , Albumina Sérica Humana/metabolismo , Espectrometria de Fluorescência/métodos , Sítios de Ligação , Fenômenos Biofísicos , Humanos , Norpregnadienos/química , Ligação Proteica , Conformação Proteica , Albumina Sérica Humana/química , TermodinâmicaRESUMO
The interactions between 2-{4-[(3S)-piperidin-3-yl] phenyl}-2H-indazole-7-carboxamide (niraparib) and human serum albumin (HSA) were investigated through fluorescence and computational studies. Fluorescence experiments showed that the static quenching mechanism and the binding constant of the HSA-niraparib system at a single binding site was approximately 4â¯×â¯104â¯Lâ¯mol-1. Thermodynamic constants indicated that the binding of niraparib to HSA was mainly driven by electrostatic interactions. Competition experiments and molecular docking simulations revealed that niraparib bound to site III of HSA. Synchronous fluorescence and Fourier transform infrared spectroscopy (FT-IR) results suggested that interactions between niraparib and HSA could affect the conformation and microenvironment of HSA. Circular dichroism (CD) measurements revealed that the α-helix contents of HSA negligibly increased after binding with niraparib. Molecular dynamics simulations demonstrated the stability of the binary HSA-niraparib system and confirmed that electrostatic forces accounted for the dominant contribution to system energy between HSA and niraparib.
Assuntos
Indazóis/química , Indazóis/metabolismo , Piperidinas/química , Piperidinas/metabolismo , Albumina Sérica Humana/química , Albumina Sérica Humana/metabolismo , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Espectrometria de Fluorescência , Eletricidade EstáticaRESUMO
The preparation of co-amorphous drug systems by adding a small molecular excipient is a promising formulation in the modern pharmaceutical industry to improve the solubility, dissolution rate, and bioavailability of poorly soluble drugs. In this study, palbociclib co-amorphous systems with organic acids (succinic, tartaric, citric, and malic acid) at molar ratios of 1 : 1 were prepared by co-milling and characterized by differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR) and solid-state nuclear magnetic resonance (SS-NMR). These solid-state investigations have confirmed the formation of co-amorphous salts between PAL and organic acids. The solubility, dissolution rate and stability of the four co-amorphous drug systems were significantly improved compared with these of crystalline and amorphous palbociclib. The biosafety of the co-amorphous drug systems was the same as that of palbociclib without affecting the efficacy of the drug and eliciting toxic side effects. These comprehensive approaches for the palbociclib-acid co-amorphous drug systems provided a theoretical basis for its clinical applications.
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Dabrafenib is a novel targeted antimelanoma drug. The present work explored the binding mechanism of dabrafenib-human serum albumin (HSA) and the effect on the esterase-like activity and antioxidant activity of HSA by using 19F NMR, spectroscopy methods, and molecular dynamics simulation. The results of 19F NMR, fluorescence, and time-resolved fluorescence spectroscopy revealed that dabrafenib spontaneously binds to the subdomain IIIA of the HSA by hydrophobic action and forms a static complex. The binding affects the esterase-like activity of HSA but not its antioxidant activity. According to the results of molecular dynamics simulation, dabrafenib interacts with Arg410 and Tyr411, which are the key residue associated with the esterase-like activity of HSA. Meanwhile, dabrafenib does not interact with Cys34, the key residue associated with the antioxidant activity of HSA. The results of circular dichroism spectroscopy and molecular dynamics simulation show that the conformation of HSA is not affected by the binding of dabrafenib. This study can provide useful information for understanding the pharmacokinetic properties of dabrafenib.
Assuntos
Antineoplásicos/farmacocinética , Esterases/metabolismo , Imidazóis/farmacocinética , Oximas/farmacocinética , Albumina Sérica Humana/metabolismo , Antineoplásicos/química , Sítios de Ligação , Dicroísmo Circular , Cisteína/metabolismo , Esterases/química , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Simulação de Dinâmica Molecular , Oximas/química , Ligação Proteica , Albumina Sérica Humana/química , Espectrometria de FluorescênciaRESUMO
This study aimed to develop a novel sustained release system for mesalazine (MSZ) by preparing hydroxypropyl-ß-cyclodextrin (HP-ß-CD) inclusion complex loaded chitosan (CS) nanoparticles (NPs). The HP-ß-CD/MSZ complex was prepared at 1:1 stoichiometry and characterized by using various analysis techniques. The HP-ß-CD/MSZ/CS NPs prepared under the optimum condition had a spherical shape (90±17 nm diameter), a narrow size distribution, and a high loading efficiency. Compared with free MSZ, the HP-ß-CD/MSZ/CS NPs exhibited an obvious sustained release of MSZ. The activity of the NPs against a cytokine-triggered inflammatory response was evaluated in cytokine-stimulated HT-29 cell lines by monitoring key inflammatory mediators. The results revealed that compared with free MSZ, the NPs more strongly inhibited the production of NO, PGE2, and IL-8, indicating the NPs possibly had better anti-inflammatory effects. Therefore, the established HP-ß-CD/MSZ/CS NPs may be a promising delivery system of MSZ.
Assuntos
2-Hidroxipropil-beta-Ciclodextrina/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Quitosana/administração & dosagem , Portadores de Fármacos/administração & dosagem , Mesalamina/administração & dosagem , Nanopartículas/administração & dosagem , 2-Hidroxipropil-beta-Ciclodextrina/química , Anti-Inflamatórios não Esteroides/química , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Dinoprostona/metabolismo , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Células HT29 , Humanos , Interleucina-8/metabolismo , Mesalamina/química , Nanopartículas/química , Óxido Nítrico/metabolismo , SolubilidadeRESUMO
Sitafloxacin (STFX) is a new generation of broad-spectrum oral fluoroquinolones. STFX has significantly enhanced antibacterial activity than most similar drugs. Clinically, this drug is mainly used to treat respiratory and urinary tract infections and other serious bacterial infections. In this study, the interaction between sitafloxacin and human serum albumin (HSA) was investigated by spectroscopic methods and molecular simulations. Fluorescence quenching experiments showed that the interaction mechanism between STFX and HSA was static quenching, which was confirmed by time-resolved fluorescence. Thermodynamic parameters and docking results indicated that hydrophobic and electrostatic forces played a key role in this mechanism. Probe experiments and molecular docking results indicated that the major binding of STFX was at site I. 3D fluorescence showed that the insertion of STFX had minimal impact on the microenvironment. Analysis of the protein secondary structure showed that the insertion of STFX had little effect on the secondary structure of the protein. Hydrophobicity experiments showed the slight decrease in the overall hydrophobicity index of the system. Molecular dynamics simulations further validated the stability of the HSA-STFX complex. This study are useful for further drug development, in vivo toxicity studies, and can provide guidance for the clinical application of STFX to study its pharmacokinetic properties.
Assuntos
Fluoroquinolonas/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Albumina Sérica Humana/química , Anti-Infecciosos , Humanos , Estrutura Secundária de Proteína , Espectrometria de Fluorescência , TermodinâmicaRESUMO
This study aims to design a novel nano-sized anticancer drug delivery system that can enhance the therapeutic effects of the loaded drug. With this idea in mind, this work reported the design and characterization of epigallocatechin-3-gallate (EGCG) functionalized chitin (CH) derivative, and its application in nano-drug delivery system. The EGCG-functionalized CH (CE) polymer was firstly prepared and characterized. The nanoparticles (NPs) of CE-loaded honokiol (HK), which was prepared by ionic crosslinking, exhibited a size of 80â¯nm, zeta potential of +33.8â¯mV, and spherical morphology. The antitumor activity of the CE-HK NPs in vitro and in vivo was investigated and compared to free HK. As a result, the CE-HK NPs can effectively inhibited cell proliferation of HepG2 cell by inhibiting more cells in the G2/M phase and decreasing mitochondrial membrane potential. The CE-HK NPs (40â¯mg/kg) inhibited tumor growth by 83.55% (pâ¯<â¯0.05), which was far higher than the 30.15% inhibition of free HK (40â¯mg/kg). The proposed delivery system exhibits better tumor selectivity and growth reduction both in vitro and in vivo, and does not induce any side effects. Therefore, the CE-HK NPs may act as an effective delivery system of liver cancer agent HK.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Compostos de Bifenilo/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Catequina/análogos & derivados , Quitina/química , Portadores de Fármacos , Lignanas/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Nanopartículas , Animais , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Compostos de Bifenilo/química , Carcinoma Hepatocelular/patologia , Catequina/administração & dosagem , Catequina/química , Proliferação de Células/efeitos dos fármacos , Reagentes de Ligações Cruzadas/química , Relação Dose-Resposta a Droga , Composição de Medicamentos , Liberação Controlada de Fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Cinética , Lignanas/química , Neoplasias Hepáticas/patologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Nanotecnologia , Tamanho da Partícula , Solubilidade , Propriedades de Superfície , Tecnologia Farmacêutica/métodos , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Ibrutinib (IBR) is a novel Bruton's tyrosine kinase inhibitor and shows good efficacy for several B-cell malignancies. In the current study, the molecular mechanism of the interaction between IBR and the transport protein human serum albumin (HSA) was ascertained by spectroscopic, calorimetric, and docking studies. Detailed investigations on affinity parameter, binding model, conformational change, and site selectivity were implemented by receptor-based and ligand-based analysis. An unusual fluorescence co-quenching (mutual quenching) was observed in the binding of IBR to HSA, followed by a static mechanism. Fluorescence spectroscopy and isothermal titration calorimetry indicated that the binding affinity was at 104â¯M-1 level and electrostatic interactions and hydrophobic forces contributed the interaction. UV-vis and 3D fluorescence spectroscopy suggested the conformational changes of HSA after binding with IBR. Fourier transform infrared and circular dichroism spectroscopy further verified the variation in the secondary structure of HSA. Site-markers competition and molecular docking confirmed that IBR preferably binds to HSA at the cysteine-rich region of Sudlow's site I (subdomain IIA). This study systematically clarified the binding process of the novel antitumor drug with the functional biomacromolecule for the first time. The findings are helpful for IBR pharmacological assessment and can provide valuable reference for other tinib-type drugs.
Assuntos
Pirazóis/metabolismo , Pirimidinas/metabolismo , Albumina Sérica Humana/metabolismo , Adenina/análogos & derivados , Antineoplásicos/metabolismo , Sítios de Ligação , Calorimetria , Dicroísmo Circular , Cisteína/química , Humanos , Simulação de Acoplamento Molecular , Piperidinas , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
ABSTRACT The PI3K/mTOR pathway is one of the most frequently aberrantly activated pathways in human malignancies, such as renal cell carcinoma (RCC), and contributes to resistance to antitumor therapies. Thus, PI3K/mTOR is an attractive target for the development of antitumor agents. In this study, we evaluated the preclinical effects of a novel inhibitor SN202. We examined Akt/mTOR activities in renal cancer cells after SN202 treatment. The preclinical effects of SN202 on tumor growth were evaluated in renal cancer cells in vitro and in murine xenografts in vivo. SN202 inhibits PI3Kα, PI3Kγ, and mTOR, the corresponding IC50 values were 3.2, 3.3, and 1.2 nM, respectively. In A498, 786-0, and ACHN renal cancer cell lines, SN202 inhibits cell proliferation in a dose-dependent manner and significantly inhibits 786-0 cell growth. Western blot analysis revealed that SN202 decreases the phosphorylation of PI3K downstream signaling molecules, Akt and S6K, in 786-0 renal cancer cells. Furthermore, oral administration of SN202 results in significant inhibition in human renal carcinoma xenografts in nude mice and favourable pharmacokinetic properties in rats. These results suggest that SN202 might be a promising therapeutic agent against RCC as a dual PI3K/mTOR inhibitor.
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This study aims to investigate the interaction mechanism of a hypoglycemic agent, trelagliptin (TLP), and human serum albumin (HSA) through computer simulation and assisted spectroscopy methods. Computer simulation including molecular docking and molecular dynamics analysis was conducted under physiological conditions. Molecular docking results indicate that TLP bound to HSA at site I, and the binding behavior was mainly governed by hydrophobic force. Competitive experiments further verified the theoretical conclusion from molecular docking. Molecular dynamics simulation revealed that TLP indeed stably bound to site I of HSA in the hydrophobic subdomain IIA. Moreover, TLP presented a certain effect on the structural compactness of HSA. In molecular dynamics simulation, hydrogen bonds appeared, which suggested the reliability and stability of the combination. The binding energy of the stable phase is around -250â¯kJ/mol. Fluorescence quenching studies and time-resolved fluorescence analysis indicated that the evident fluorescence quenching phenomenon of HSA could be due to TLP binding initiated by static quenching mechanism. The binding constants (Ka) of the complex were found to be around 104 via fluorescence data, and the calculated thermodynamic parameters indicated that hydrophobic force played major role in the binding of TLP to HSA. Synchronous fluorescence and three-dimensional fluorescence results demonstrated that TLP slightly disturbed the microenvironment of amino residues. Circular dichroism spectra showed that TLP affected the secondary structure of HSA. The theoretical and experimental results showed excellent agreement.