Binding of Janus kinase inhibitor tofacitinib with human serum albumin: multi-technique approach

The interactions of novel anti-cancer therapeutic agents with the different plasma and tissue components, specifically serum albumins, have lately gained considerable attention due to the significant influence of such interactions on the pharmacokinetics and/or -dynamics of this important class of therapeutics. Nazartinib (EGF 816; NAZ) is a new anti-cancer candidate proposed as a third-generation epidermal growth factor receptor tyrosine kinase inhibitor that is being developed and clinically tested for the management of non-small cell lung cancer. The current study aimed to characterize the interaction between NAZ and human serum albumin (HSA) using experimental and theoretical approaches. Experimental results of fluorescence quenching of HSA induced by NAZ revealed the development of a statically formed complex between NAZ and HSA. Interpretation of the observed fluorescence data using Stern–Volmer, Lineweaver–Burk and double-log formulae resulted in binding constants for HSA-NAZ complex in the range of (2.34–2.81) × 10 4 M –1 over the studied temperatures. These computed values were further used to elucidate thermodynamic attributes of the interaction, which showed that NAZ spontaneously binds to HSA with a postulated electrostatic force-driven interaction. This was further verified by theoretical examination of the NAZ docking on the HSA surface that revealed an HSA-NAZ complex where NAZ is bound to HSA Sudlow site I driven by hydrogen bonding in addition to electrostatic forces in the form of pi-H bond. The HSA binding pocket for NAZ was shown to encompass ARG 257, ARG 222, LYS 199 and GLU 292 with a total binding energy of −25.59 kJ mol –1 .

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Human Serum Albumin Nanoparticles as a Carrier for On-Demand Sorafenib Delivery

Current Pharmaceutical Biotechnology ◽

10.2174/1389201022666210826152311 ◽

2021 ◽

Vol 22 ◽

Author(s):

Tania Caputo ◽

Angela Maria Cusano ◽

Menotti Ruvo ◽

Anna Aliberti ◽

Andrea Cusano

Keyword(s):

Drug Delivery ◽

Human Serum Albumin ◽

Drug Release ◽

Serum Albumin ◽

Human Serum ◽

Encapsulation Efficiency ◽

Kinase Inhibitor ◽

Force Microscopy ◽

Atomic Force

Background: Drug delivery systems based on Human Serum Albumin (HSA) have been widely investigated due to their capability to interact with several molecules together with their nontoxicity, non-immunogenicity and biocompatibility. Sorafenib (SOR) is a kinase inhibitor used as the first-line treatment in hepatic cancer. However, because of its several intrinsic drawbacks (low solubility and bioavailability), there is a growing need for discovering new carriers able to overcome the current limitations. Objective: To study HSA particles loaded with SOR as a thermal responsive drug delivery system. Method: A detailed spectroscopy analysis of the HSA and SOR interaction in solution was carried out in order to characterize the temperature dependence of the complex. Based on this study, the synthesis of HSA particles loaded with SOR was optimized. Particles were characterized by Dynamic Light Scattering, Atomic Force Microscopy and by spectrofluorometer. Encapsulation efficiency and in vitro drug release were quantified by RP-HPLC. Results: HSA particles were monodispersed in size (≈ 200 nm); encapsulation efficiency ranged from 25% to 58%. Drug release studies that were performed at 37 °C and 50 °C showed that HS5 particles achieved a drug release of 0.430 µM in 72 hours at 50 °C in PBS buffer, accomplishing a 4.6-fold overall SOR release enhancement following a temperature increase from 37 °C to 50 °C. Conclusion: The system herein presented has the potential to exert a therapeutic action (in the nM range) triggering a sustained temperature-controllable release of relevant drugs.

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