Physicochemical Characterization of Oleanolic Acid–Human Serum Albumin Complexes for Pharmaceutical and Biosensing Applications

Abstract

Among numerous compounds found in marine organisms, triterpenes have attracted considerable research interest due to a beneficial impact on health including anti-inflammatory, antitumor, antiviral, and antioxidation effects. Specifically, new functionalities of oleanolic acid (OLA) have been revealed recently, indicating possible applications in nutrition and pharmaceuticals. However, this bioactive material has limited value due to low water solubility and stability. Therefore, oleanolic acid needs a carrier that protects it and enables controlled release in the human body. Innovative drug delivery systems provide a promising strategy for overcoming these problems. However, the development of those systems requires a comprehensive understanding of the physicochemical properties of triterpenes and their carriers as well as the interactions between them. Among numerous substances, human serum albumin (HSA) has been widely studied as a drug carrier. In addition, human serum albumin is the main blood plasma protein responsible for the transport of drugs and metabolites; therefore, the interactions between that protein and other substances are of physiological and pharmaceutical importance. Moreover, sensing the HSA level in blood plasma is an important challenge that requires binding studies on a molecular scale. The aim of this study was to investigate the properties of oleanolic acid in the presence of human serum albumin in terms of thermodynamics, morphology, and viscoelasticity at the air/water interface. Moreover, the wettability, surface free energy, and topography of the films after deposition on the solid substrate were determined. The results have been discussed in terms of providing physicochemical insight into the interfacial behavior of the OLA–HSA complex, which is crucial for pharmaceutical and bioanalytical applications.

Oleanolic Acid: Extraction, Characterization and Biological Activity

“…The thermodynamic analysis showed that the basic forces acting between bovine serum albumin and the triterpene were hydrogen bonds, van der Waals forces and hydrophobic interactions [ 85 ]. Dopierala et al [ 86 ] found that the binding of OA to albumin can be irreversible according to pH, ionic strength and temperature, which may have a significant impact on the distribution of oleanolic acid in the human body. Peng et al [ 85 ], Bhattacharya et al [ 87 ] and Subramanyam et al [ 88 ] anticipated that the complexation of plant triterpenoids with protein might be exploited as a biologically relevant model for evaluating the physiologically applicable no-covalent complexes in the in vivo examination of triterpenoid properties such as accumulation, bioavailability and distribution.…”

Surface Functionalization of Poly(lactic acid) via Deposition of Hydroxyapatite Monolayers for Biomedical Applications

“…Several publications have appeared recently documenting LB films built of gold nanoparticles, zinc oxide, , magnetic nanoparticles and nanowires, , fullerenes, graphene, and graphene oxide. , Ariga introduced the concept of nanoarchitectonics, which uses a liquid interface to form controlled nanostructures for nanosensing, nanophotonics, and molecular electronics . In addition, much research on complex, multicomponent monolayers has been done including thermodynamic characterization, rheological studies, and deposition on various substrates. − For instance, various biomolecules can be incorporated into the lipid monolayer such as proteins, , chitosan, collagen, and keratin as well as xenobiotics, , extending the applications of Langmuir films in the biomedical field.…”

Effect of Silica Microparticles on Interactions in Mono- and Multicomponent Membranes

“…Monolayers are formed at the air–water interface, which allows for the acquisition of a lot of information about the interactions and the physicochemical properties of its components. To obtain stable lipid monolayers that simulate biological model membranes, the Langmuir method can be used, which is a good technique to study the structures and properties of lipids, proteins and surfactants [ 16 , 17 , 18 ]. Furthermore, the properties of model lipid monolayers are similar to those of real biological membranes [ 19 , 20 ].…”