Formation and characterization of lactoferrin/pectin electrostatic complexes: Impact of composition, pH and thermal treatment

Thermal stability and in vitro biological fate of lactoferrin-polysaccharide complexes

Lactoferrin (LF) is a thermally sensitive iron-binding globular glycoprotein. Heat treatment can induce its denaturation and aggregation and thus affect its functional activity. In this study, carrageenan (CG), xanthan gum (XG) and locust bean gum (LBG), allowed to apply in infant food, were used to form protein-polysaccharide complexes to improve the thermal stability of LF. Meanwhile, in vitro simulated infant digestion and absorption properties of LF were also estimated. The results showed that the complexes formed by CG and XG with LF (LF-CG and LF-XG) could significantly inhibit the loss of α-helix structure of LF against heating. LF-CG and LF-LBG could protect LF from digestion in simulated infant gastric fluid and slow down the degradation of LF under the simulated intestinal conditions. Besides, LF, LF-CG and LF-XG showed no adverse effects on the growth of Caco-2 cells in the LF concentration range of 10-300 μg/mL, and LF-XG exhibited better beneficial to improve the cell uptake of the digestive product than the other protein-polysaccharides at the LF concentration of 100 µg/mL. This study may provide a reference for the enhancement of thermal processing stability of LF and development infant food ingredient with high nutrients absorption efficiency in the gastrointestinal environment in the future.

Lactoferrin/pectin nanocomplex encapsulating ciprofloxacin and naringin as a lung targeting antibacterial nanoplatform with oxidative stress alleviating effect

Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium with adaptive metabolic abilities. It can cause hospital-acquired infections with significant mortality rates, particularly in people with already existing medical conditions. Its ability to develop resistance to common antibiotics makes managing this type of infections very challenging. Furthermore, oxidative stress is a common consequence of bacterial infection and antibiotic therapy, due to formation of reactive oxygen species (ROS) during their mode of action. In this study we aimed to alleviate oxidative stress and enhance the antibacterial efficacy of ciprofloxacin (CPR) antibiotic by its co-encapsulation with naringin (NAR) within a polyelectrolyte complex (PEX). The PEX comprised of polycationic lactoferrin (LF) and polyanionic pectin (PEC). CPR/NAR-loaded PEX exhibited spherical shape with particle size of 237 ± 3.5 nm, negatively charged zeta potential (-23 ± 2.2 mV) and EE% of 61.2 ± 4.9 for CPR and 76.2 ± 3.4 % for NAR. The LF/PEC complex showed prolonged sequential release profile of CPR to limit bacterial expansion, followed by slow liberation of NAR, which mitigates excess ROS produced by CPR's mechanism of action without affecting its efficacy. Interestingly, this PEX demonstrated good hemocompatibility with no significant in vivo toxicity regarding hepatic and renal functions. In addition, infected mice administrated this nanoplatform intravenously exhibited significant CFU reduction in the lungs and kidneys, along with reduced immunoreactivity against myeloperoxidase. Moreover, this PEX was found to reduce the lungs´ oxidative stress via increasing both glutathione (GSH) and catalase (CAT) levels while lowering malondialdehyde (MDA). In conclusion, CPR/NAR-loaded PEX can offer a promising targeted lung delivery strategy while enhancing the therapeutic outcomes of CPR with reduced oxidative stress.

Ultrasonic and homogenization: An overview of the preparation of an edible protein-polysaccharide complex emulsion

Emulsion systems are extensively utilized in the food industry, including dairy products, such as ice cream and salad dressing, as well as meat products, beverages, sauces, and mayonnaise. Meanwhile, diverse advanced technologies have been developed for emulsion preparation. Compared with other techniques, high-intensity ultrasound (HIUS) and high-pressure homogenization (HPH) are two emerging emulsification methods that are cost-effective, green, and environmentally friendly and have gained significant attention. HIUS-induced acoustic cavitation helps in efficiently disrupting the oil droplets, which effectively produces a stable emulsion. HPH-induced shear stress, turbulence, and cavitation lead to droplet disruption, altering protein structure and functional aspects of food. The key distinctions among emulsification devices are covered in this review, as are the mechanisms of the HIUS and HPH emulsification processes. Furthermore, the preparation of emulsions including natural polymers (e.g., proteins-polysaccharides, and their complexes), has also been discussed in this review. Moreover, the review put forward to the future HIUS and HPH emulsification trends and challenges. HIUS and HPH can prepare much emulsifier-stable food emulsions, (e.g., proteins, polysaccharides, and protein-polysaccharide complexes). Appropriate HIUS and HPH treatment can improve emulsions' rheological and emulsifying properties and reduce the emulsions droplets' size. HIUS and HPH are suitable methods for developing protein-polysaccharide forming stable emulsions. Despite the numerous studies conducted on ultrasonic and homogenization-induced emulsifying properties available in recent literature, this review specifically focuses on summarizing the significant progress made in utilizing biopolymer-based protein-polysaccharide complex particles, which can provide valuable insights for designing new, sustainable, clean-label, and improved eco-friendly colloidal systems for food emulsion. PRACTICAL APPLICATION: Utilizing complex particle-stabilized emulsions is a promising approach towards developing safer, healthier, and more sustainable food products that meet legal requirements and industrial standards. Moreover, the is an increasing need of concentrated emulsions stabilized by biopolymer complex particles, which have been increasingly recognized for their potential health benefits in protecting against lifestyle-related diseases by the scientific community, industries, and consumers.

Improving Effects of Laccase-Mediated Pectin–Ferulic Acid Conjugate and Transglutaminase on Active Peptide Production in Bovine Lactoferrin Digests

Bovine lactoferrin (bLf) is a multifunctional glycoprotein and a good candidate for producing diverse bioactive peptides, which are easily lost during over-digestion. Accordingly, the effects of laccase-mediated pectin–ferulic acid conjugate (PF) and transglutaminase (TG) on improving the production of bLf active peptides by in vitro gastrointestinal digestion were investigated. Using ultra-high-performance liquid chromatography tandem mass spectroscopy (UPLC-MS-MS), the digests of bLf alone, PF-encapsulated bLf complex (LfPF), and TG-treated LfPF complex (LfPFTG) produced by conditioned in vitro gastric digestion (2000 U/mL pepsin, pH 3.0, 37 °C, 2 h) were identified with seven groups of active peptide-related fragments, including three common peptides (VFEAGRDPYKLRPVAAE, FENLPEKADRDQYEL, and VLRPTEGYL) and four differential peptides (GILRPYLSWTE, ARSVDGKEDLIWKL, YLGSRYLT, and FKSETKNLL). The gastric digest of LfPF contained more diverse and abundant detectable peptides of longer lengths than those of bLf and LfPFTG. After further in vitro intestinal digestion, two active peptide-related fragments (FEAGRDPYK and FENLPEKADRDQYE) remained in the final digest of LfPFTG; one (EAGRDPYKLRPVA) remained in that of bLf alone, but none remained in that of LfPF. Conclusively, PF encapsulation enhanced the production of bLf active peptide fragments under the in vitro gastric digestion applied. TG treatment facilitated active peptide FENLPEKADRDQYE being kept in the final gastrointestinal digest.

Tuning alginate β-lactoglobulin complex coacervation by modulating pH and temperature

The use of biomolecules in food matrices and encapsulation systems is, as in other areas, moving towards greener solutions and a center piece here is the complex coacervation between natural anionic polysaccharides and proteins. Both alginate and β-lactoglobulin (β-Lg) are used in different sectors and have been shown to coacervate at pH < 5.2. Albeit with increased interest, complex coacervation has almost exclusively been studied from a macromolecular perspective, and described as an interaction based on charge-charge attraction. Here, we show that through changes in pH and temperature, alginate β-Lg complex coacervation can be tuned to purpose. By detailed biophysical and chemical characterization of coacervation and coacervate particles, insights into the molecular interaction and effect of external factors are obtained. We find that carboxylate resonance stabilization causes a release of protons at pH < pK_a,alginate and an uptake of protons at pH > pK_a,alginate upon coacervation. Proton release and uptake were quantified at pH 2.65 and 4.00 by isothermal titration calorimetry to be 4 and 2 protons per β-Lg molecule, respectively. By increasing the temperature to 65 °C, we discovered a secondary β-Lg concentration dependent coacervation step, where the formed particles change into large assemblies driven by entropy. These findings bring new insights to complex coacervation and its applicability in microencapsulation and drug delivery.

High internal phase emulsions stabilized by native and heat-treated lactoferrin-carboxymethyl chitosan complexes: Comparison of molecular and granular emulsifiers

While the high internal phase emulsions (HIPEs) have been formed by food-grade biopolymers and granules have been widely reported, it is not known which components are more effective. In this work, we first used heat-treated lactoferrin (LF)-carboxymethyl chitosan (CMCTS) granules and native LF-CMCTS physical mixtures as emulsifiers to form HIPEs. The results showed that the interfacial behavior and emulsifying properties of the two complexes were controlled by the ratio of LF-CMCTS and the optimal ratio of LF to CMCTS was 1:1. Heated LF-CMCTS granules anchored to the water-oil interface and formed an elastic shell to stabilize HIPEs, while unheated LF-CMCTS complexes formed a thick film layer to stabilize HIPEs. Both HIPEs could act as delivery systems loaded with curcumin, and they showed better protection of curcumin than Tween-80 under light. This study provides a new basis for the design of LF-based HIPEs systems loaded with lipophilic food functional ingredients.

Load phycocyanin to achieve in vivo imaging of casein-porous starch microgels induced by ultra-high-pressure homogenization

Traditional bioactive substances are often limited in practical application due to their poor stability and low solubility. Therefore, it is imperative to develop biocompatible high loading microgel carriers. In this study, a novel type of casein-porous starch microgel was prepared under ultra-high-pressure homogenization, by using porous starch with the honeycomb three-dimensional network porous structure. Molecular interaction force analysis and thermodynamic analysis showed that electrostatic interaction played a major role in the formation of microgels. Circular dichroism and Fourier transform infrared spectroscopy showed that homogenization and pH were the main factors, which affected the formation and structural stability of microgels. Compared with casein-glutinous rice starch microgels, the encapsulation efficiency and loading capacity of phycocyanin in casein-porous starch microgels were increased by 77.27% and 135.10%, respectively. Thus, casein-porous starch microgels could not only achieve a sustained release effect, but also effectively transport phycocyanin to the gastrointestinal tract of zebrafish, while achieving good fluorescence imaging in vivo. Ultimately, the prepared casein-porous starch microgels could enrich the nanocarriers material, and contribute to the research of safe and effective fluorescent imaging materials.

Bioactives in bovine milk: chemistry, technology, and applications

The significance of dairy in human health and nutrition is gaining significant momentum as consumers continue to desire wholesome, nutritious foods to fulfill their health and wellness needs. Bovine milk not only consists of all the essential nutrients required for growth and development, it also provides a broad range of bioactive components that play an important role in managing human homeostasis and immune function. In recent years, milk bioactives, including α-lactalbumin, lactoferrin, glycomacropeptide, milk fat globule membrane, and milk oligosaccharides, have been intensively studied because of their unique bioactivity and functionality. Challenges for the application of these bioactive components in food and pharmaceutical formulations are associated with their isolation and purification on an industrial scale and also with their physical and chemical instability during processing, storage, and digestion. These challenges can be overcome by advanced separation techniques and sophisticated nano- or micro-encapsulation technologies. Current knowledge about the chemistry, separation, and encapsulation technology of major bioactives derived from bovine milk and their application in the food industry is reviewed here.

Development of Encapsulation Strategies and Composite Edible Films to Maintain Lactoferrin Bioactivity: A Review

Lactoferrin (LF) is a whey protein with various and valuable biological activities. For this reason, LF has been used as a supplement in formula milk and functional products. However, it must be considered that the properties of LF can be affected by technological treatments and gastrointestinal conditions. In this article, we have revised the literature published on the research done during the last decades on the development of various technologies, such as encapsulation or composite materials, to protect LF and avoid its degradation. Multiple compounds can be used to conduct this protective function, such as proteins, including those from milk, or polysaccharides, like alginate or chitosan. Furthermore, LF can be used as a component in complexes, nanoparticles, hydrogels and emulsions, to encapsulate, protect and deliver other bioactive compounds, such as essential oils or probiotics. Additionally, LF can be part of systems to deliver drugs or to apply certain therapies to target cells expressing LF receptors. These systems also allow improving the detection of gliomas and have also been used for treating some pathologies, such as different types of tumours. Finally, the application of LF in edible and active films can be effective against some contaminants and limit the increase of the natural microbiota present in meat, for example, becoming one of the most interesting research topics in food technology.

Nanotechnological Manipulation of Nutraceuticals and Phytochemicals for Healthy Purposes: Established Advantages vs. Still Undefined Risks

Numerous foods, plants, and their bioactive constituents (BACs), named nutraceuticals and phytochemicals by experts, have shown many beneficial effects including antifungal, antiviral, anti-inflammatory, antibacterial, antiulcer, anti-cholesterol, hypoglycemic, immunomodulatory, and antioxidant activities. Producers, consumers, and the market of food- and plant-related compounds are increasingly attracted by health-promoting foods and plants, thus requiring a wider and more fruitful exploitation of the healthy properties of their BACs. The demand for new BACs and for the development of novel functional foods and BACs-based food additives is pressing from various sectors. Unfortunately, low stability, poor water solubility, opsonization, and fast metabolism in vivo hinder the effective exploitation of the potential of BACs. To overcome these issues, researchers have engineered nanomaterials, obtaining food-grade delivery systems, and edible food- and plant-related nanoparticles (NPs) acting as color, flavor, and preservative additives and natural therapeutics. Here, we have reviewed the nanotechnological transformations of several BACs implemented to increase their bioavailability, to mask any unpleasant taste and flavors, to be included as active ingredients in food or food packaging, to improve food appearance, quality, and resistance to deterioration due to storage. The pending issue regarding the possible toxic effect of NPs, whose knowledge is still limited, has also been discussed.

Development of astaxanthin-loaded layer-by-layer emulsions: physicochemical properties and improvement of LPS-induced neuroinflammation in mice

Astaxanthin (AST) has been shown to have neuroprotective effects; however, its bioavailability in vivo is low due to its hydrophobic properties. In this study, lactoferrin (LF) was prepared by heat-treatment at different temperatures, and on this basis, a layer-by-layer self-assembly method was used to construct double-layer emulsions with LF as the inner layer and polysaccharide (beet pectin, BP or carboxymethyl chitosan, CMCS) as the outer layer. Then AST was encapsulated in the emulsions and their physiochemical properties and function were investigated. The results indicated that high temperature heated LF (95 °C) showed a more stable structure than the lower temperature one, and the exposed internal nonpolar groups of LF could give the emulsion an enhanced stability. The rheology results showed that compared with CMCS, the double-layer emulsion formed by BP had a higher viscosity. In addition, the 95 °C LF-AST-BP emulsion showed the best stability among all the bilayer emulsions. The best emulsion was then used as a model drug to investigate its effects on lipopolysaccharide (LPS)-induced neuroinflammation and learning-memory loss in C57BL/6J mice. Through animal behavioral experiments, it was found that dietary supplementation with the AST emulsion could effectively improve the brain cognitive and learning memory impairment caused by inflammation. Transmission electron microscopy, mRNA and western blotting results also illustrated that the AST emulsion could alleviate neuroinflammation caused by LPS. This study provides a feasible scheme for exploring an AST loaded system and may be suitable for food and drug applications.

Lactoferrin: an overview of its main functions, immunomodulatory and antimicrobial role, and clinical significance

Lactoferrin (LF), a glycoprotein found in mucosal secretions, is characterized by a wide range of functions, including immunomodulatory and anti-inflammatory activities. Moreover, several investigations confirmed that LF displays high effectiveness against multiple bacteria and viruses and may be regarded as a potential inhibitor of enveloped viruses, such as presently prevailing SARS-CoV-2. In our review, we discuss available studies about LF functions and bioavailability of different LF forms in in vitro and in vivo models. Moreover, we characterize the potential benefits and side effects of LF use; we also briefly summarize the latest clinical trials examining LF application. Finally, we point potential role of LF in inflammatory bowel disease and indicate its use as a marker for disease severity.

Phytochemical delivery through nanocarriers: a review

In recent times, phytochemicals encapsulated or conjugated with nanocarriers for delivery to the specific sites have gained considerable research interest. Phytochemicals are mostly plant secondary metabolites which reported to be beneficial for human health and in disease theraphy. However, these compound are large size and polar nature of these compounds, make it difficult to cross the blood-brain barrier (BBB), endothelial lining of blood vessels, gastrointestinal tract and mucosa. Moreover, they are enzymatically degraded in the gastrointestinal tract. Therefore, encapsulation or conjugation of these compounds with nanocrriers could be an alternate way to enhance their bioefficacy by influencing their gastrointestinal stability, rate of absorption and dispersion. This review presents an overview of nanocarriers alternatives which improves therapeutic value and avoid toxicity, by releasing bioactive compounds specifically at target tissues with enhanced stability and bioavailability. Future investigations may emphasize on deciphering the structural changes in nanocarriers during digestion and absorption, the difference between in-vitro and in-vivo digestion simulations, and impact of nanocarriers on the metabolism of phytochemicals.

Lactoferrin, a multi-functional glycoprotein: Active therapeutic, drug nanocarrier & targeting ligand

Recent progress in protein-based nanomedicine, inspired by the success of Abraxane® albumin-paclitaxel nanoparticles, have resulted in novel therapeutics used for treatment of challenging diseases like cancer and viral infections. However, absence of specific drug targeting, poor pharmacokinetics, premature drug release, and off-target toxicity are still formidable challenges in the clinic. Therefore, alternative protein-based nanomedicines were developed to overcome those challenges. In this regard, lactoferrin (Lf), a glycoprotein of transferrin family, offers a promising biodegradable well tolerated material that could be exploited both as an active therapeutic and drug nanocarrier. This review highlights the major pharmacological actions of Lf including anti-cancer, antiviral, and immunomodulatory actions. Delivery technologies of Lf to improve its pries and enhance its efficacy were also reviewed. Moreover, different nano-engineering strategies used for fabrication of drug-loaded Lf nanocarriers were discussed. In addition, the use of Lf for functionalization of drug nanocarriers with emphasis on tumor-targeted drug delivery was illustrated. Besides its wide application in oncology nano-therapeutics, we discussed the recent advances of Lf-based nanocarriers as efficient platforms for delivery of anti-parkinsonian, anti-Alzheimer, anti-viral drugs, immunomodulatory and bone engineering applications.

Addition of Anionic Polysaccharide Stabilizers Modulates In Vitro Digestive Proteolysis of a Chocolate Milk Drink in Adults and Children

There is a need to better understand the possible anti-nutritional effect of food stabilizers on the digestibility of important macronutrients, like proteins. This study hypothesized that the anionic nature of κ-, ι-, λ-, Carrageenan (CGN) and xanthan gum directs their interactions with food proteins leading to their subsequent attenuated digestive proteolysis. Model chocolate milk drinks were tested for their colloidal properties, viscosity and proteolytic breakdown in adults and children using in vitro digestion models coupled with proteomic analyses. SDS-PAGE analyses of gastro-intestinal effluents highlight stabilizers hinder protein breakdown in adults and children. Zeta potential and colloidal particle size were the strongest determinants of stabilizers’ ability to hinder proteolysis. LC-MS proteomic analyses revealed stabilizer addition significantly reduced bioaccessibility of milk-derived bioactive peptides with differences in liberated peptide sequences arising mainly from their location on the outer rim of the protein structures. Further, liberation of bioactive peptides emptying from a child stomach into the intestine were most affected by the presence of ι-CGN. Overall, this study raises the notion that stabilizer charge and other properties of edible proteins are detrimental to the ability of humans to utilize the nutritional potential of such formulations. This could help food professionals and regulatory agencies carefully consider the use of anionic stabilizers in products aiming to serve as protein sources for children and other liable populations.

Preparation and characterization of zein/carboxymethyl dextrin nanoparticles to encapsulate curcumin: Physicochemical stability, antioxidant activity and controlled release properties

In this work, zein/carboxymethyl dextrin nanoparticles were successfully fabricated at different zein to carboxymethyl dextrin (CMD) mass ratios. Zein/CMD nanoparticles with the negative charge and the smallest size (212 nm) were formed when the mass ratio of zein to CMD was 2:1, exhibiting improved encapsulation efficiency of curcumin (85.5%). Electrostatic interactions, hydrogen bonding and hydrophobic interactions were main driven forces for nanoparticles formulation and curcumin encapsulation. Fourier transform infrared spectroscopy determined curcumin might be partially embedded in CMD during encapsulation. The spherical structures of zein/CMD nanoparticles and curcumin-loaded zein/CMD nanoparticles were observed by transmission electron microscopy. The photothermal stability and antioxidant activity of curcumin were significantly enhanced after be loaded in zein/CMD nanoparticles. Furthermore, encapsulation of curcumin in zein/CMD nanoparticles significantly delayed the release of curcumin in simulated gastrointestinal fluids. These results indicated that zein/CMD nanoparticles could be effective encapsulating materials for bioactive compounds in food industry.

Characterization and enhanced functionality of nanoparticles based on linseed protein and linseed gum biocomplexes

The formation, characterization, and functionality of hybrid nanoparticles based on linseed bio-macromolecules extracted as linseed protein (LP) and linseed gum (LG) from the remaining meal after oil extraction were investigated. The assembly of bioparticles at different protein to polysaccharide ratios as a function of pH was characterized in terms of absorbance measurements, dynamic light scattering and surface charge. The wettability of the assembled particles as well as the plain LP and LG was also determined. By increasing the LG proportion in the bioparticles, both the size of the particles and their contact angle tended to decrease, whereas their zeta potential became more negative over the whole studied pH range. The formed negatively charged particles at pH 3 with a 50:50 LP to LG ratio and a size of approximately 300 nm were selected and their functional properties (solubility, emulsifying and foaming properties) were compared to the individual biopolymers. The interaction between LG and LP was found to modify the functional properties of native LP especially at and around its isoelectric point. The LP-LG particles could be useful for stabilizing plant-based emulsions and foams.

Effect of lactoferrin on physicochemical properties and microstructure of pullulan-based edible films

BACKGROUND

Pullulan is a polysaccharide polymer commonly used to produce edible films. However, pure pullulan film is usually brittle and very hydrophilic, which limit its use in both food and pharmaceutical fields. The objective of this research is to improve the structural and mechanical properties of pullulan film by incorporating globular protein lactoferrin (LF).

RESULTS

The incorporation of LF increased the surface hydrophobicity and decreased the water vapor permeability (WVP) of pullulan film. The presence of low concentrations of LF (< 0.03%) has no significant influence on tensile strength (TS) and elongation at break (EAB) of pullulan film. However, further increase of LF concentration to levels > 0.03% resulted in a film-weakening effect. LF molecules aggregated with each other during the film-producing process, which presented as spherical particles from the observation of microscopy. LF aggregates dispersed homogeneously throughout the pullulan matrix and their size increased with increasing concentration. Analysis from Fourier transform infrared spectroscopy indicated that the secondary structure of LF molecules was modified during the drying process.

CONCLUSIONS

It is possible to increase the hydrophobicity of pullulan film while maintaining its mechanical properties. The produced composite film can be potentially used for food and medical packaging. © 2019 Society of Chemical Industry.

Fabrication and Characterization of Layer-by-Layer Composite Nanoparticles Based on Zein and Hyaluronic Acid for Codelivery of Curcumin and Quercetagetin

The utilization of layer-by-layer composite nanoparticles fabricated from zein and hyaluronic acid (HA) for the codelivery of curcumin and quercetagetin was investigated. A combination of hydrophobic effects and hydrogen bonding was responsible for the interaction of zein with both curcumin and quercetagetin inside the nanoparticles. Electrostatic attraction and hydrogen bonding were mainly responsible for the layer-by-layer deposition of hyaluronic acid on the surfaces of the nanoparticles. The secondary structure of zein was altered by the presence of the two nutraceuticals and HA. The optimized nanoparticle formulation contained relatively small particles ( d = 231.2 nm) that were anionic (ζ = -30.5 mV). The entrapment efficiency and loading capacity were 69.8 and 2.5% for curcumin and 90.3 and 3.5% for quercetagetin, respectively. Interestingly, the morphology of the nanoparticles depended on their composition. In particular, they changed from coated nanoparticles to nanoparticle-filled microgels as the level of HA increased. The nanoparticles were effective at reducing light and thermal degradation of the two encapsulated nutraceuticals and remained physically stable throughout 6 months of long-term storage. In addition, the nanoparticles were shown to slowly release the nutraceuticals under simulated gastrointestinal tract conditions, which may help improve their oral bioavailability. In summary, we have shown that layer-by-layer composite nanoparticles based on zein and HA are an effective codelivery system for two bioactive compounds.

Comparison of structural and physicochemical properties of lysozyme/carboxymethylcellulose complexes and microgels

Proteins and polysaccharides can be used to assemble colloidal delivery systems suitable for industrial applications, such as functional foods, supplements, pharmaceuticals, and personal care products. The purpose of this work was to compare the physicochemical and structural properties of colloidal delivery systems prepared from lysozyme and carboxymethyl cellulose (CMC) at different biopolymer ratios, pH values, and salt levels. Specifically, the performance of unheated ("complexes") and heated ("microgels") lysozyme-CMC systems were compared. Isothermal turbidity-pH titrations indicated that the critical pH value for complex formation was lower for microgels than for complexes. Complexes were prone to dissociation when the pH or ionic strength was altered due to weakening of electrostatic interactions between the CMC and lysozyme. Conversely, microgels remained intact when the pH or ionic strength was altered, exhibiting swelling or shrinkage rather than dissociation. These results have important implications for the selection of the most appropriate protein/polysaccharide systems to achieve specific functional requirements. Complexes may be more suitable for pH- or salt-based triggered release whereas microgels may be more suitable for sustained release.

Fabrication and characterization of functional protein–polysaccharide–polyphenol complexes assembled from lactoferrin, hyaluronic acid and (−)-epigallocatechin gallate

Functional lactoferrin–EGCG–hyaluronic acid complexes could be conditionally assembled at different pH values.

Immobilization of β-galactosidase by complexation: Effect of interaction on the properties of the enzyme

In the present work, we aimed to explore the molecular binding between alginate and β-galactosidase, as well as the effect of this interaction on the activity retention, thermal stability, and kinetic properties of the enzyme. The impact of pH and enzyme/alginate ratio on physicochemical properties (turbidity, morphology, particle size distribution, ζ-potential, FTIR, and isothermal titration calorimetry) was also evaluated. The ratio of biopolymers and pH of the system directly affected the critical pH of complex formation; however, a low alginate concentration (0.1 wt%) could achieve an electrical charge equivalence at pH 3.4 with 93.72% of yield. The binding between β-galactosidase and alginate was an equilibrium between enthalpic and entropic contributions, which promoted changes in the structure of the enzyme. Nevertheless, this conformational modification was reversible after the dissociation of the complex, which allowed the enzyme to regain its activity. These findings will likely broaden functional applications of enzyme immobilization.

Zein-hyaluronic acid binary complex as a delivery vehicle of quercetagetin: Fabrication, structural characterization, physicochemical stability and in vitro release property

The antisolvent coprecipitation method was utilized for fabricating the zein and hyaluronic acid complex at different mass ratios (100:5, 100:10, 100:15, 100:20, 100:25 and 100:30). Results showed that negatively charged zein-hyaluronic acid complex with small size (181.5 nm) was formed through the driving force of electrostatic attraction, followed by hydrogen bonding and hydrophobic effects. The incorporation of hyaluronic acid led to conformational change of zein, and improved its physical and thermal stability. Native hyaluronic acid showed a three-dimensional network structure, while zein-hyaluronic acid binary complex exhibited two different microstructures, including nanoparticles (zein: hyaluronic acid, above 100:20) and particle-filled-microgel (zein: hyaluronic acid, below 100:20). In addition, zein-hyaluronic acid complex was designed as a new delivery vehicle to anti- thermal degradation and control release of quercetagetin. These findings indicated that zein-hyaluronic acid complex would be a useful and promising delivery vehicle for embedding and protecting bioactive compounds.

Protein-polysaccharide nanohybrids: Hybridization techniques and drug delivery applications

Complex nanosystems fabricated by hybridization of different types of materials such as lipids, proteins, or polysaccharides are usually superior to simple ones in terms of features and applications. Proteins and polysaccharides hold great potential for development of nanocarriers for drug delivery purposes based on their unique biocompatibility, biodegradability, ease of functionalization, improved biodistribution and minimal toxicity profiles. Protein-polysaccharide nanohybrids have gained a lot of attention in the past few years particularly for drug delivery applications. In this review, different hybridization techniques utilized in the fabrication of such nanohybrids including electrostatic complexation, Maillard conjugation, chemical coupling and electrospinning were thoroughly reviewed. Moreover, various formulation factors affecting the characteristics of the formed nanohybrids were discussed. We also reviewed in depth the outcomes of such hybridization ranging from stability enhancement, to toxicity reduction, improved biocompatibility, and drug release modulation. We also gave an insight on their limitations and what hinders their clinical translation and market introduction.