Fractionation of Soybean Globulins Using Ca2+ and Mg2+: A Comparative Analysis

Cellulose nanocrystals based delivery vehicles for anticancer agent curcumin

Cancer is a complex disease that starts with genetic alterations and mutations in healthy cells. The past decade has witnessed a huge demand for new biocompatibility and high-performance intelligent drug delivery systems. Curcumin (CUR) is a bioactive stimulant with numerous medical benefits. However, because of its hydrophobic nature, it has low bioavailability. The utilization of many biobased materials has been found to improve the loading of hydrophobic drugs. Cellulose nanocrystals (CNCs) with exceptional qualities and a wide range of applications, feature strong hydrophilicity and lipophilicity, great emulsification stability, high crystallinity and outstanding mechanical attributes. In this review, numerous CNCs-based composites have been evaluated for involvement in the controlled release of CUR. The first part of the review deals with recent advancements in the extraction of CNCs from lignocellulose biomass. The second elaborates some recent developments in the post-processing of CNCs in conjunction with other materials like natural polymers, synthetic polymers, β-CD, and surfactants for CUR loading/encapsulation and controlled release. Furthermore, numerous CUR drug delivery systems, challenges, and techniques for effective loading/encapsulation of CUR on CNCs-based composites have been presented. Finally, conclusions and future outlooks are also explored.

Preparation and Properties of Fractionated Soybean Protein Isolate Films

Soybean protein isolate (SPI) and its four fractionated products (7S globulin, 11S globulin, upper soybean residue, and lower soybean residue) were compared by fabricating films and film liquids. The separation and grading effects, rheological properties of the film liquids, and difficulty in uncovering the films, in addition to the mechanical properties, water vapor permeability, oil permeability, and surface morphology of the films, were investigated. Results showed that the centrifugal precipitation method could be used to produce fractionated products. The 7S and 11S globulin films exhibited better hydrogels at lower shear rates than the other SPIs; however, they were more difficult to uncover. The tensile strength of the graded films decreased by varying degrees. However, the elongation at the break of the upper soybean residue film considerably increased, reaching 70.47%. Moreover, the permeability and surface morphology of the film were enhanced or weakened. The fractionated products, 7S and 11S globulin films, exhibited better performance. Overall, this study provides a basis for the improved development and use of fractioned SPI products.

Separation of Storage Proteins (7S and 11S) from Soybean Seed, Meals and Protein Isolate Using an Optimized Method Via Comparison of Yield and Purity

The primary purpose of this study was to extract β-conglycinin (7S) and glycinin (11S) from soybean seed, soybean meals and soybean protein isolate and compare their yield and purity. The previous methods were modified for the extraction and isolation of 7S and 11S globulins. The adjustment mainly included sample to solution ratio of 1:10 (previously 1:15). Comparing the yield of 11S fraction in Tris-HCl and water as extractable solutions, it was almost doubled in soybean seed (16.97% to 32.41%) with purity from 96 to 98% respectively. In case of soybean meal, samples yield increased from 45.46 to 61.86% with purity from 94 to 98%. On contrary, 7S yield was significantly improved in soybean protein isolate sample from 30.33 to 53.81% along with no contamination in its purity while soybean seed and soybean meal samples had less increase in both yield and purity in Tris-HCl and water as extractable solutions. Results of this study will bring new insights into soybean 7S and 11S separation and purification techniques as well as pave the way for their application in food industry.

Fabrication of soy protein isolate/cellulose nanocrystal composite nanoparticles for curcumin delivery

In this study, we developed novel complex nanoparticles as carriers for curcumin (Cur) delivery by using soy protein isolate (SPI) and cellulose nanocrystals (CNC) as polymer matrices. We found that the SPI-to-CNC mass ratio influenced the stability and physical properties of the SPI-CNC complex nanoparticles. Moreover, SPI-CNC complex nanoparticles had a relatively small size (197.7 ± 0.2 nm) and low polydispersity index (0.14) at a 6:1 mass ratio. The nanosystem was relatively stable at different pH values (3-9), temperatures (30-90 °C), and salt concentrations (0-40 mmol/L). Furthermore, the complex nanoparticles exhibited a high encapsulation efficiency (88.3%) and sustained release during simulated gastrointestinal digestion. Therefore, SPI-CNC complex nanoparticles are a promising delivery system for hydrophobic bioactive compounds.

Recent trends in protein and peptide-based biomaterials for advanced drug delivery

Engineering protein and peptide-based materials for drug delivery applications has gained momentum due to their biochemical and biophysical properties over synthetic materials, including biocompatibility, ease of synthesis and purification, tunability, scalability, and lack of toxicity. These biomolecules have been used to develop a host of drug delivery platforms, such as peptide- and protein-drug conjugates, injectable particles, and drug depots to deliver small molecule drugs, therapeutic proteins, and nucleic acids. In this review, we discuss progress in engineering the architecture and biological functions of peptide-based biomaterials -naturally derived, chemically synthesized and recombinant- with a focus on the molecular features that modulate their structure-function relationships for drug delivery.

Facile continuous production of soy peptide nanogels via nanoscale flash desolvation for drug entrapment

A facile continuous production of soy peptide nanogels was demonstrated using a multi-inlet vortex micromixer for the entrapment of active ingredients. The full flow regime in the micromixer was systematically studied to understand the flow impact on nanogel size, drug encapsulation efficiency and drug loading efficiency. Ibuprofen was chosen as a model drug to demonstrate encapsulation capability. The study showed that the nanogel size, drug encapsulation efficiency and drug loading efficiency did not alter significantly as long as the flow rates were in transition and turbulent regimes. The driving force behind the folding of peptides within the microenvironment is kinetic mixing with high flow rates, which dominates in comparison to molecular diffusion, nucleation, and growth. Moreover, the hydrophilic-lipophilic balance of the soy peptides determined the drug encapsulation efficiency and the drug loading efficiency, which did not vary much under different manufacturing parameters. Both characteristics are beneficial to mass production of drug-entrapped peptide. In a 50% water-ethanol mixture, the encapsulation efficiency achieved 70% and the drug loading efficiency was up to 25% in transition and turbulent flow regimes. This work opens the avenues to continuous production of drug-entrapped soy peptide nanogels using a multi-inlet vortex micromixer.

Folic acid-conjugated soybean protein-based nanoparticles mediate efficient antitumor ability in vitro

In this study, soy protein isolate was hydrolyzed by compound enzymes to give aqueous soy protein with low molecular weights. Folic acid modified and free soy protein nanoparticles were successfully prepared by a desolvation method as target-specific drug delivery, respectively. Ultraviolet spectrophotometry demonstrated that folic acid was successfully grafted onto soy protein. The shape and size of folic acid modified soy protein nanoparticles were detected by transmission electron microscopy, scanning electron microscope, and dynamic light scattering. In addition, a series of characteristics including kinetic stability, pH stability, and time stability were also performed. Doxorubicin was successfully loaded into folic acid modified soy protein nanoparticles, and the encapsulation and loading efficiencies were 96.7% and 23%, respectively. Doxorubicin-loaded folic acid modified soy protein nanoparticles exhibited faster drug release rate than soy protein nanoparticles in PBS solution (pH = 5). The tumor penetration and antitumor experiments were done using three-dimensional multicellular tumor spheroids as the in vitro model. The results proved that folic acid modified soy protein nanoparticles display higher penetration and accumulation than soy protein nanoparticles, therefore possessing efficient growth inhibitory ability against multicellular tumor spheroids.

Coagulation of β-conglycinin, glycinin and isoflavones induced by calcium chloride in soymilk

The coagulation of β-conglycinin (7S), glycinin (11S) and isoflavones induced by calcium chloride was investigated. Approximately 92.6% of the soymilk proteins were coagulated into the soymilk pellet fraction (SPF) after the addition of 5 mM calcium chloride. SDS-PAGE and two-dimensional electrophoresis analysis indicated that most of the 7S (α', α and β), 11S acidic (A1a, A1b, A2, A3 and A4) and 11S basic (B1a) proteins in the SSF were coagulated into the SPF after treatment with 5 mM calcium chloride. Isoflavones, including daidzein and genistein, were also coagulated into the SPF after the addition of 5 mM calcium chloride. The amounts of daidzein and genistein in the SSF decreased to 39.4 ± 1.6 and 11.8 ± 7.0%, respectively. HPLC analysis suggested that daidzein and genistein were bound with 7S and 11S proteins and then were coprecipitated into the SPF by 5 mM calcium chloride.

Protein nanoparticles as drug delivery carriers for cancer therapy

Nanoparticles have increasingly been used for a variety of applications, most notably for the delivery of therapeutic and diagnostic agents. A large number of nanoparticle drug delivery systems have been developed for cancer treatment and various materials have been explored as drug delivery agents to improve the therapeutic efficacy and safety of anticancer drugs. Natural biomolecules such as proteins are an attractive alternative to synthetic polymers which are commonly used in drug formulations because of their safety. In general, protein nanoparticles offer a number of advantages including biocompatibility and biodegradability. They can be prepared under mild conditions without the use of toxic chemicals or organic solvents. Moreover, due to their defined primary structure, protein-based nanoparticles offer various possibilities for surface modifications including covalent attachment of drugs and targeting ligands. In this paper, we review the most significant advancements in protein nanoparticle technology and their use in drug delivery arena. We then examine the various sources of protein materials that have been used successfully for the construction of protein nanoparticles as well as their methods of preparation. Finally, we discuss the applications of protein nanoparticles in cancer therapy.

Formation of complex interface and stability of oil-in-water (O/W) emulsion prepared by soy lipophilic protein nanoparticles

A lipophilic protein nanoparticle (LPP) was fabricated by ultrasonication of the soy lipophilic protein (LP), which contains hydrophobic proteins and phospholipids. This LPP (Rh = 136 ± 0.8 nm, ζ-potential = -20 mV, pH 7.0) had an improved dispersibility and acted as an emulsifier. The oil/water (O/W) emulsion stabilized by this LPP exhibited superior physical stability over long-term storage (8 weeks), during a stress storage test (200 mM NaCl addition and heating at 90 °C), and in the presence of Tween 20 (1.0-4.0 wt %), in contrast to those emulsions stabilized by β-conglycinin and glycinin. Langmuir-Blodgett method and interface pressure determination revealed that LPP formed rigid and rough granular film at air/water interface. The excellent stability of emulsions stabilized by LPP highlights the synergic effect between hydrophobic proteins and phospholipids. These findings suggest that the complexes of hydrophobic protein aggregates and biosurfactant could form a stable interface which could be developed into a novel strategy to fabricate a stable food emulsion.

Nanoparticles synthesized from soy protein: preparation, characterization, and application for nutraceutical encapsulation

Nanoparticles were synthesized from soy protein, one of the most abundant and widely utilized plant proteins, for nutraceutical and drug encapsulation. The preparation process consisted of dispersion, desolvation, drug incorporation, cross-linking, and evaporation. The role of each procedure in the formation of nanoparticles was systematically investigated by means of particle size, size distribution, and zeta potential as well as morphology observation. Curcumin as a model drug was encapsulated successfully into the nanoparticles, evidenced by Fourier transform infrared spectroscopy and X-ray diffraction patterns. The average size of the curcumin-loaded nanoparticles was 220.1 to 286.7 nm, and their zeta potential was around -36 mV. The highest encapsulation efficiency and loading efficiency achieved were 97.2% and 2.7%, respectively. The release of curcumin in phosphate buffer saline followed a biphasic pattern. Possible mechanisms of the formation of soy protein nanoparticles as well as the incorporation of curcumin were discussed based on the data obtained from this study.

Isolation of glycinin (11S) from lipid-reduced soybean flour: effect of processing conditions on yields and purity

Defatted soybean flour was treated with hexane and ethanol to reduce lipid content and heated to inactivate lipoxygenase (LOX, linoleate:oxygen reductase; EC 1.13.11.12) to obtain lipid-reduced soybean flour (LRSF). The effects of processing conditions such as pH, reducing agent and storage time on yields and purity of glycinin (11S) were evaluated in the fractionation of soybean glycinin isolated from LRSF. Adjusting the pH of protein extract from 6.2 to 6.6, the yield of glycinin decreased by 16.71%, while the purity of the protein increased by 4.60%. Sulfhydryl and disulfide content of proteins increased by degrees with increasing pH. Compared with dithiothreitol (DTT) or β-mercaptoethanol (ME) as reducing agent, the yield of glycinin was the highest when sodium bisulfite (SBS) was added to the protein extract at pH 6.4. The effect of DTT on yields of glycinin was the lowest of the three kinds of reducing agent. The purity of glycinin was similar when the three kinds of reducing agent were used. These results showed that SBS was the best choice for the isolation of 11S-rich fraction. Prolonging storage time in the precipitation stage, 10 h was the best for yields and purity of glycinin in the experiment, while there was no significant difference at P ≥ 0.05 for total sulfhydryl and disulfide content. The decreased free sulfhydryl content of glycinin indicated that the oxidation of free sulfhydryls and the formation of disulfide bonds occurred when the extraction time was prolonged.