Cationic β-lactoglobulin nanoparticles as a bioavailability enhancer: Comparison between ethylenediamine and polyethyleneimine as cationizers

Structural and tribological studies on the interaction of porcine gastric mucin with non- and cationic-modified β-lactoglobulins

β-lactoglobulin (BLG) is the major whey protein with negative charges at neutral pH in aqueous media. Thus, the interaction with mucins, the major polyanionic component of mucus, is very weak due to the electrostatic repulsion between them. The present study postulates that cationization of BLG molecules may reverse the interaction characteristics between BLG and mucin from repulsive to associative. To this end, cationic-modified BLGs were prepared by grafting positively charged ethylenediamine (EDA) moieties into the negatively charged carboxyl groups on the aspartic and glutamic acid residues and compared with non-modified BLG upon mixing with porcine gastric mucin (PGM). To characterize the structural and conformational features of PGM, non/cationized BLGs, and their mixtures, various spectroscopic approaches, including zeta potential, dynamic light scattering (DLS), and circular dichroism (CD) spectroscopy were employed. Importantly, we have taken surface adsorption with optical waveguide lightmode spectroscopy (OWLS), and tribological properties with pin-on-disk tribometry at the sliding interface as the key approaches to determine the interaction nature between them as mixing PGM with polycations can lead to synergistic lubrication at the nonpolar substrate in neutral aqueous media as a result of an electrostatic association. All the spectroscopic studies and a substantial improvement in lubricity collectively supported a tenacious and associative interaction between PGM and cationized BLGs, but not between PGM and non-modified BLG. This study demonstrates a unique and successful approach to intensify the interaction between BLG and mucins, which is meaningful for a broad range of disciplines, including food science, macromolecular interactions, and biolubrication etc.

Soy protein interactions with polyphenols: Structural and functional changes in natural and cationized forms

Herein, cationic soy protein (NSPI) was synthesized by grafting Ethylenediamine (EDA) onto soy protein isolate (SPI), and protein-gallic acid (GA) complexes were formed by mixing NSPI with GA in various ratios. We assessed the structure, particle size, thermal stability, emulsifying ability, and antioxidant capacity of NSPI and complexes. Results show that grafting with EDA introduced a positive charge to SPI and resulted in a uniform particle size, and enhanced thermal stability, emulsifying ability, and antioxidant capacity. In addition, NSPI presented more amino groups and stronger interactions with GA compared to SPI. EDA and GA synergistically increased the flexibility of SPI, reducing the α-helix content and increasing the random coil content. Moreover, the interactions between SPI, NSPI, and GA were static, and hydrophobic and electrostatic between GA and SPI and NSPI, respectively. Grafting SPI with EDA improved functionality and interactions with GA, implying that NSPI-GA complexes may function as emulsifiers and antioxidants.

Protein-Based Delivery Systems for Anticancer Metallodrugs: Structure and Biological Activity of the Oxaliplatin/β-Lactoglobulin Adduct

β-lactoglobulin is the major component of whey. Here, the adduct formed upon the reaction of the protein with oxaliplatin (OXA) has been prepared, structurally characterized by X-ray crystallography and electrospray ionization–mass spectrometry, and evaluated as a cytotoxic agent. The data demonstrate that OXA rapidly binds β-lactoglobulin via coordination with a Met7 side chain upon release of the oxalate ligand. The adduct is significantly more cytotoxic than the free drug and induces apoptosis in cancer cells. Overall, our results suggest that metallodrug/β-lactoglobulin adducts can be used as anticancer agents and that the protein can be used as a metallodrug delivery system.

Cisplatin binding to β-lactoglobulin: a structural study

The first structural study on the interaction of β-lactoglobulin with the anticancer compound cisplatin is here reported by combining spectroscopic, crystallographic and mass spectrometry techniques.

Protein-Based Nanostructures for Food Applications

Proteins are receiving significant attention for the production of structures for the encapsulation of active compounds, aimed at their use in food products. Proteins are one of the most used biomaterials in the food industry due to their nutritional value, non-toxicity, biodegradability, and ability to create new textures, in particular, their ability to form gel particles that can go from macro- to nanoscale. This review points out the different techniques to obtain protein-based nanostructures and their use to encapsulate and release bioactive compounds, while also presenting some examples of food grade proteins, the mechanism of formation of the nanostructures, and the behavior under different conditions, such as in the gastrointestinal tract.

Development of nanoformulation approaches for the control of weeds

The nanoformulation of pesticides has the potential to increase food productivity, while resolving the drawbacks of conventional agrochemicals, which have negative environmental impacts. In this study, herbicide (metsulfuron methyl)-loaded pectin (polysaccharide) nanoparticles were synthesized and evaluated for herbicidal activity and cytotoxicity. The optimum formulation of nanoparticles was obtained using the Central Composite Design. The basic properties (mean particle size, stability, morphology, and interaction between polymer and herbicide) were characterized using a particle size analyzer (PSA), zeta potential, transmission electron microscopy (TEM), and Fourier Transform infrared spectroscopy (FTIR), respectively. The nanoparticles were found to be in size range of 50-90nm with zeta potential value of -35.9mV. The herbicide loading and herbicide encapsulation efficiency of the nanoparticles were determined to be 6.30% and 63±2%, respectively. The cytotoxicity of the herbicide-loaded nanoparticles was evaluated using healthy cell lines (Vero cell lines) and compared with that of commercial herbicide. In addition, an in-field evaluation of our nanoformulation's effects on the Chenopodium album plant was performed using a pectin nanocarrier. The results showed that application of herbicide-loaded nanoparticles could be used to reduce the use of herbicides with improved efficacy and environmental safety.

β-Lactoglobulin: An efficient nanocarrier for advanced delivery systems

Thanks to the progress of nanotechnology there are several agent-delivery systems that can be selected to achieve rapid and specific delivery of a wide variety of biologically active agents. Consequently, the manipulation and engineering of biopolymers has become one of the most exciting subjects for those who study delivery systems on the nanoscale. In this regard, both nanoparticle formation and a carrier role have been observed in the case of the globular milk whey protein, β-lactoglobulin (β-LG), setting it apart from many other proteins. To date, many efforts adopting different approaches have created β-LG nanoparticles useful in forming delivery systems for various agents with specific targets. In this review, the potential of β-LG to play the role of an efficient and diverse carrier protein, as well as its ability to form a well-targeted nano-scale delivery system is discussed.

Effects of Desolvating Agent Types, Ratios, and Temperature on Size and Nanostructure of Nanoparticles from α-Lactalbumin and Ovalbumin

In this study, we compare the preparation of ovalbumin (OVA) and α-lactalbumin (α-LA) nanoparticles using different desolvating agents (ethanol, acetone, and methanol) and water: desolvating agent volume ratios (1:3, 1:4, 1:5, 1:10, and 1:20). Also the effects of protein solution temperature (25, 50, and 80 ℃) on the size of nanoparticles and the stability of crosslinked nanoparticles for 30 d were studied. OVA and α-LA were shown to be good candidates for nanoparticulation and nanoparticles in the range of 60 to 230 nm were obtained. The comparison between the 2 proteins offers guidance to optimize OVA and α-LA nanoparticle fabrication and to efficiently obtain nanoparticles with desired characteristics. The particle sizes of OVA nanoparticles were found to be in the range of 60 to 160 nm, and the particle sizes of α-LA were between 150 and 230 nm. The sizes varied with different desolvating agents: for OVA, ethanol, and methanol both produced nanoparticles smaller than 100 nm; for α-LA, methanol produced the smallest nanoparticles. Water: desolvating agent ratios, in the studied range, did not show a significant effect on the particle sizes for both OVA and α-LA nanoparticles. The size and morphology of the nanoparticles were found to change when the protein solutions were heated up to 50 and 80 ℃ and cooled down before nanoparticulation and most nanoparticles had a smaller diameter.

Cationic beta-lactoglobulin nanoparticles as a bioavailability enhancer: Effect of surface properties and size on the transport and delivery in vitro

BLG (beta-lactoglobulin) and CBLG (cationic BLG developed by our lab) were evaluated as potential nutraceutical/drug carriers. The cationic corona conferred CBLG with superior integrity and drug retention under gastrointestinal conditions, at most 40-fold higher mucoadhesion, up to 30-fold greater transepithelial permeation and, at most 285% higher cellular uptake, compared to BLG. Furthermore, the more hydrophilic CBLG species exhibited better mucoadhesion, while the more hydrophobic one exhibited higher cellular uptake. Intriguingly, protein molecules were more cytotoxic and exhibited up to 175% higher tight junction-opening capacity than did protein nanoparticles, whereas the nanoparticles displayed up to 770% higher mucoadhesion, greater transepithelial permeation and elevated cellular uptake. Finally, all these surface properties and performances were significantly altered as CBLG bound to serum proteins. Possible mechanisms underlying these findings are discussed in detail. This research sheds some light on the development of protein-based nanoencapsulants and their performance upon oral administration.

Enhanced delivery of daidzein into fibroblasts and neuronal cells with cationic derivatives of gamma-cyclodextrin for the control of cellular glycosaminoglycans

Two cationic derivatives of γ-cyclodextrin (GCD) were synthesized by functionalization with glycidyltrimethylammonium chloride (GTMAC) and ethylenediamine (EDA). Both these derivatives (GCD-GTMAC and GCD-EDA) have been shown to interact strongly with anionic biopolymers, unfractionated heparin (UFH) and mucin, the latter showing their mucoadhesive properties. They form inclusion complexes with daidzein (DAI), an isoflavone displaying a multitude of physiological effects, much more efficiently than the unmodified GCD. It was also shown that the complexes of these GCD derivatives with DAI and Nile Red penetrate human fibroblasts and murine hippocampal neuronal cells indicating that cationic GCD derivatives can be considered as potential delivery systems for isoflavones and other poorly water soluble compounds. Moreover, it was found that DAI delivered in cationic GCD complexes decreased the level of the cellular glycosaminoglycans (GAGs) in normal fibroblasts suggesting their possible application in the control of GAGs in mucopolysaccharidoses, lysosomal storage diseases caused by pathological accumulation of GAGs in the cells.

Beta-lactoglobulin-based encapsulating systems as emerging bioavailability enhancers for nutraceuticals: a review

Encapsulating systems prepared with beta-lactoglobulin, the major component of whey protein, may serve as versatile bioavailability enhancers for poorly absorbed nutraceuticals.

Insight into curcumin-loaded β-lactoglobulin nanoparticles: incorporation, particle disintegration, and releasing profiles

This study aimed at developing protein nanoparticles with desirable loading efficiency (LE) and low cross-linker concentration. Using β-lactoglobulin (BLG) and curcumin as a model system, this work demonstrated that the LE could be improved by up to 157% by maintaining low antisolvent content before mild evaporation. Moreover, the optimal level of glutaraldehyde decreased by 50% as the curcumin/protein ratio increased, suggesting that toxic cross-linkers could be partly replaced with natural phenols such as curcumin. The BLG-curcumin nanoparticles showed average size of 164-214 nm, zeta potential of -42 mV, and LE of up to 11%. Interestingly, BLG nanoparticles demonstrated rapid disintegration and nutraceutical release in simulated gastric fluid (SGF) at pH 2, despite the known resistance of BLG against pepsin. However, they maintained integrity in SGF at pH 5. This phenomenon, followed by extensive degradation in simulated intestinal fluid, suggested the controlled-release property of BLG nanoparticles when administered orally.