Model Protein Adsorption on Polymers Explained by Hansen Solubility Parameters

Bovine serum albumin (BSA) protein is widely used to fabricate antifouling coatings for nanobiotechnology applications. Numerous BSA protein options are commercially available and obtained through different purification methods, however, there is no guidance on which ones are preferable for antifouling coatings. Herein, we investigate the real-time fabrication of antifouling coatings composed of BSA proteins obtained through different purification methods, and report significant differences in ultrathin film coating properties and ability to mitigate serum biofouling and to prevent nanoparticle-induced immune reactions. Mechanistic studies unravel the source of these performance variations, which are related to some BSA proteins containing fatty acid stabilizers while other BSA proteins are fatty acid-free depending on the purification method. Fatty acid-free BSA proteins exhibit greater conformational flexibility and less charge repulsion, which allow them to form more rigidly attached and tightly packed coatings on flat surfaces and nanoparticles that result in superior application performance.

Preliminary study of adsorption behavior of bovine serum albumin (BSA) protein and its effect on antibacterial and corrosion property of Ti-3Cu alloy

Natural proteins such as bovine serum albumin (BSA) are readily extracted from biological fluids and widely used in various applications such as drug delivery and surface coatings. It is standard practice to dope BSA proteins with an amphipathic stabilizer, most commonly fatty acids, during purification steps to maintain BSA conformational properties. There have been extensive studies investigating how fatty acids and related amphiphiles affect solution-phase BSA conformational properties, while it is far less understood how amphipathic stabilizers might influence noncovalent BSA adsorption onto solid supports, which is practically relevant to form surface coatings. Herein, we systematically investigated the binding interactions between BSA proteins and different molar ratios of caprylic acid (CA), monocaprylin (MC), and methyl caprylate (ME) amphiphiles-all of which have 8-carbon-long, saturated hydrocarbon chains with distinct headgroups-and resulting effects on BSA adsorption behavior on silica surfaces. Our findings revealed that anionic CA had the greatest binding affinity to BSA, which translated into greater solution-phase conformational stability and reduced adsorption-related conformational changes along with relatively low packing densities in fabricated BSA adlayers. On the other hand, nonionic MC had moderate binding affinity to BSA and could stabilize BSA conformational properties in the solution and adsorbed states while also enabling BSA adlayers to form with higher packing densities. We discuss physicochemical factors that contribute to these performance differences, and our findings demonstrate how rational selection of amphiphile type and amount can enable control over BSA adlayer properties, which could lead to improved BSA protein-based surface coatings.

Adsorption of bovine serum albumin on amorphous carbon surfaces studied with dip pen nanolithography

Surface pattern by nanoimprint for membrane fouling mitigation: Design, performance and mechanisms

Inflammation is a manifestation of the immune response to eliminate antigens and a process to respond to tissue damage. There are various drugs to control and suppress inflammation, referred to as anti-inflammatory agents. One method to test anti-inflammatory activity is the inhibition of Bovine Serum Albumin (BSA) protein denaturation. This review article will discuss the stages and optimal conditions in the inhibition of BSA protein denaturation method using various leaf extract samples. Literature was gathered from several journal database websites such as PubMed, ScienceDirect, and Google Scholar with keywords "anti-inflammatory," "inhibition of BSA protein denaturation," and "leaf extract," spanning publication years from 2002 to 2023. The results of anti-inflammatory activity tests can be expressed as either percentage inhibition or IC50 values. Optimal conditions were obtained by preparing a 0.2% BSA solution with Tris Buffer Saline (TBS), maintaining a 9:1 composition ratio between the BSA solution and the sample, and heating at an optimal denaturation temperature of 70 °C. Before conducting tests using this method, it is crucial to ensure that the suspected active compounds with anti-inflammatory activity are not degraded at this heating temperature.

The organically modified montmorillonite (M‐Mt) was applied as an adsorbent for the purification of bovine serum albumin (BSA). In order to differentiate the selectivity and perform the purification of BSA, two kinds of proteins, BSA and lysozyme (LYZ) were mixed together and prepared at different pH, which could change the electrical charges on the surfaces of the proteins. BSA and LYZ can be adsorbed at the lower pH into the organically modified montmorillonite, which could be confirmed by powder X‐ray diffraction (XRD) in the d‐value increased after the adsorption of proteins. However, there is only BSA desorption was observed, approved by the method of Sodium dodecyl sulfate (SDS)‐polyacrylamide gel electrophoresis (PAGE), from this adsorbed protein mixture when the pH of the solution was adjusted and optimized. These results indicate that there is electrostatic interaction between a suitably modified montmorillonite and proteins BSA and LYZ to perform the selective desorption from BSA in the mixture of these proteins.

Selective adsorption of acidic protein of bovine serum albumin onto sheet-like calcium hydroxyapatite particles produced by microreactor

The surface chemistry of ions, water molecules, and proteins as well as their ability to form stable networks in foams can influence and control macroscopic properties such as taste and texture of dairy products considerably. Despite the significant relevance of protein adsorption at liquid interfaces, a molecular level understanding on the arrangement of proteins at interfaces and their interactions has been elusive. Therefore, we have addressed the adsorption of the model protein bovine serum albumin (BSA) at the air-water interface with vibrational sum-frequency generation (SFG) and ellipsometry. SFG provides specific information on the composition and average orientation of molecules at interfaces, while complementary information on the thickness of the adsorbed layer can be obtained with ellipsometry. Adsorption of charged BSA proteins at the water surface leads to an electrified interface, pH dependent charging, and electric field-induced polar ordering of interfacial H(2)O and BSA. Varying the bulk pH of protein solutions changes the intensities of the protein related vibrational bands substantially, while dramatic changes in vibrational bands of interfacial H(2)O are simultaneously observed. These observations have allowed us to determine the isoelectric point of BSA directly at the electrolyte-air interface for the first time. BSA covered air-water interfaces with a pH near the isoelectric point form an amorphous network of possibly agglomerated BSA proteins. Finally, we provide a direct correlation of the molecular structure of BSA interfaces with foam stability and new information on the link between microscopic properties of BSA at water surfaces and macroscopic properties such as the stability of protein foams.

Gold nanoparticles synthesized from Bacopa monneri plant extract: Bovine serum albumin protein interactions and antibacterial effectiveness

The interaction of an anti-gout drug, febuxostat was studied with bovine serum albumin (BSA) applying fluorescence quenching method for the first time. Interaction parameter and magnitude of the force indicated for both, dynamic and static quenching in between febuxostat and BSA protein. Thermodynamic studies indicated for both hydrogen and hydrophobic interactions, observed at 280 nm and only hydrophobic at 293 nm excitation wavelength. Negative ΔHo and positive ΔSo, indicated for distinctive characteristics for the existence of both, hydrogen and hydrophobic binding throughout the interactions. The binding constant Kb at λex=280 nm was 3.467 × 103 μM-1 and 4.943 × 103 μM-1 at 298 and 308 K temperature whereas, 5.54 × 103 μM-1 and 4.44 × 103 μM-1 was noted during excitation at λex=293 nm wavelength. The Kb values in different temperatures assumed that the stability of binding increased with the increase of temperature at λex=280 nm, but reverse effect was experienced at an excitation wavelength of λex=293 nm. The number of bound febuxostat molecules per BSA protein was found ~1.5 at both 298 and 308 K.

In this study, we firstly investigated the surface and protein adsorption properties of montmorillonite (MMT)/chitosan (CS) composite films with various MMT/CS weight ratios for metallic implants coating applications. Bicinchoninic acid (BCA) protein assay results show that the neat CS film exhibits a high concentration of bovine serum albumin (BSA) protein adhesion because the abundant carbonyl and amide functional groups on the surface of the CS film easily form hydrogen bonds with the copious carboxylic acid groups on the surface of the BSA protein. The MMT/CS composite films with MMT/CS = 3, 5, 8, and 10 possess a much lower BSA adhesion concentration than that of the neat CS film, as some of the carbonyl and amide functional groups on the surface of the composite films are replaced by the –Si–O–Si and –Al–O–Al groups. Among these MMT/CS composite films, the film with MMT/CS = 5 exhibits the lowest BSA adsorption concentration because it possesses a higher MMT content than those with MMT/CS = 1 and 3 and a smoother and non-porous surface than those with MMT/CS = 8 and 10. According to our results, MMT/CS composite films with appropriate MMT/CS weight ratios exhibit better surface and protein adsorption properties than neat CS for biomedical applications.

A criterion of diluent selection for the polymeric membrane formation via thermally induced phase separation process based on Hansen solubility parameter theory

Protein-encapsulated nanoclusters (NCs) are emerging as a versatile platform for in-vivo imaging and other biomedical applications due to their ultrasmall size and excitation in the near-infrared region. Encapsulation may however affect protein structure, size, charge, and its interaction with lipid membranes. In this study, bulk characterization methods along with surface-sensitive vibrational sum-frequency generation (VSFG) spectroscopy were employed to study the secondary structure of bovine serum albumin (BSA) with blue-emitting Au8NCs at the air/water and 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DPPG) lipid/water interfaces. With this approach, the difference in the adsorption behavior between native BSA and BSA with an increasing number of blue-emitting NCs was investigated under different pH conditions. At pH 7, at which both BSA and the lipid are negatively charged, protein molecules are found to associate with the DPPG monolayer via hydrophobic interactions with no preferential orientation across the lipid monolayer. At pH 3, adsorption of BSA at the DPPG monolayer occurs mainly due to electrostatic interactions between the negatively charged lipid headgroups and the positively charged protein, resulting in a uniform orientation of the protein across the lipid monolayer. Complimentary bulk studies by circular dichroism and particle size measurements show that the encapsulation of Au8NCs is associated with the loss of BSA helicity, which makes BSA-encapsulated Au8NCs prone to oligomerization, especially at a high content of Au8NCs at one BSA protein. The results indicate that the hydrodynamic diameter of BSA with Au8NCs strongly depends on the molar fraction of gold, the pH, and the storage time. A prolonged storage of Au8NCs@BSA at pH 7 increases the rate of protein oligomerization.

Low band-gap energy photocatalytic membrane based on SrTiO3–Cr and PVDF substrate: BSA protein degradation and separation application