Stability-Indicating Analytical Approach for Stability Evaluation of Lactoferrin

Technical note: optimizing and validating an RP-HPLC method to determine lactoferrin in porcine colostrum and milk

This Technical Note provides a detailed description of a sample preparation procedure, along with the validation of a reversed-phase high-performance liquid chromatography (RP-HPLC) method for quantitatively determining lactoferrin (LF) in porcine colostrum and milk. The analysis of native milk samples is a challenging process due to the complex composition of the sample. Raw milk is an emulsion and colloid of fat globules in a water-based liquid containing dissolved carbohydrates and protein aggregates with minerals. This paper aims to optimize a method for preparing porcine colostrum and milk samples, which involves a new combination of homogenization, centrifugation, dilution, and filtration techniques for the subsequent analysis of LF via RP-HPLC. A validation process was implemented to ensure the reliability and repeatability of this analytical approach. The results showed that the quantification of LF content in porcine colostrum (1,684.58 ± 466.68 µg/mL; n = 10) and milk (849.75 ± 85.82 µg/mL; n = 10) is feasible with successful validation. In addition, the improved sensitivity due to the novel combination of these preparation steps is shown by low limits of detection and quantification of 0.21 µg/mL each. The advantage of this optimized methodology is that the sample preparation can be carried out relatively simply and using standard laboratory equipment, thus enabling the accurate determination of LF in porcine colostrum and milk samples.

Enteric Coated Pellets with Lactoferrin for Oral Delivery: Improved Shelf Life of the Product

BACKGROUND/OBJECTIVES

Lactoferrin (Lf), a multifunctional iron-binding protein, has considerable potential for use as an active ingredient in food supplements due to its numerous positive effects on health. As Lf is prone to degradation, we aimed to develop a formulation that would ensure sufficient stability of Lf in the gastrointestinal tract and during product storage.

METHODS

A simple, efficient, and well-established technology that has potential for industrial production was used for the double-coating of neutral pellet cores with an Lf layer and a protective enteric coating.

RESULTS

The encapsulation efficiency was 85%, which is among the highest compared to other reported Lf formulations. The results of the dissolution tests performed indicated effective protection of Lf from gastric digestion. A comprehensive stability study showed that the stability was similar regardless of the neutral pellet core used, while a significant influence of temperature, moisture, product composition, and packaging on the stability of Lf were observed, and were therefore considered in the development of the final product. The experimentally determined shelf life is extended from 15 to almost 30 months if the product is stored in a refrigerator instead of at room temperature, which ensures the commercial applicability of the product.

CONCLUSION

We successfully transferred a technology commonly used for small molecules to a protein-containing product, effectively protected it from the destructive effects of gastric juice, and achieved an acceptable shelf life.

A Comprehensive Analytical Approach for Quality Control of Collagen in Food Supplements

Collagen is a popular nutricosmetic ingredient in food supplements due to its anti-aging and other positive effects on the skin. Due to its widespread use and the lack of regulation in this area, appropriate quality control is required to ensure efficacy and safety, with the development of analytical methods playing an important role. Currently, the quantitative determination of collagen is mainly based on time-consuming derivatization-based spectroscopic methods or on complex chromatographic methods with mass spectrometric detection. Therefore, in this study, two new, simple chromatographic methods have been developed. One is intended for the analysis of untreated samples and is characterized by the speed and simplicity of sample preparation. The other method quantifies collagen via the underivatized tripeptide Gly-Pro-Hyp formed by bacterial collagenase hydrolysis and is characterized by its specificity and ability to distinguish between marine and terrestrial collagen. The latter is a novelty in the field of simple methods for collagen analysis and is particularly important in terms of safety. Our comparison with established analytical methods (e.g., via hydroxyproline after complete hydrolysis) for collagen analysis undoubtedly showed the superiority of these new methods for the routine quality control of collagen supplements in terms of specificity, repeatability, sample stability, and simplification in sample preparation. The collagen content in the supplements tested was found to be adequate; however, some discrepancies were found regarding the labeling and origin of the collagen, with possible safety implications.

Investigating topical delivery of erythromycin laden into lipid nanocarrier for enhancing the anti-bacterial activity

Skin infections considered as one of the predominant disorders that could greatly influence humans. Topical drug delivery is believed to be an effective substitute to systemically delivered medication for skin disorders management. Erythromycin has been proven to retain anti-bacterial activity. Based on that, the aim of existent study is to develop a proper nanocarrier, namely; nanoemulsion using tea tree oil including Erythromycin. Applying quality by design approach, the optimized nanoemulsion was selected based on number of independent variables namely; particle size and in vitro release study. Yet, in order to get appropriate topical application, the optimized nanoemulsion was combined with previously prepared hydrogel base to provide Erythromycin based nanoemulgel. The developed nanoemulgel was assessed for its organoleptic and physical characters to ensure its suitability for topical application. Stability study was implemented over three months after being kept in two distinct environments. Eventually, the antibacterial behavior of the preparation was investigated on MRSA to verify the expected antibacterial improvement and validate the effectiveness of the developed nanocarrier. The formulation showed consistent appearance, with pH (6.11 ± 0.19), viscosity (10400 ± 1275 cP), spreadability (54.03 ± 2.3 mm), extrudability (80.36 ± 3.15 g/cm2) and drug content (99.3 ± 0.46 %) that seemed to be satisfied for topical application. It could provide 48.1 ± 4.2 % releases over 6 h in addition to be stable at room temperature and at refrigerator. Ultimately, the formula showed a significant antibacterial activity against MRSA proving the combination and the nanocarrier effectiveness.

Impact of Ultrafiltration on the Physicochemical Properties of Bovine Lactoferrin: Insights into Molecular Mass, Surface Morphology, and Elemental Composition

The large-scale isolation of bovine lactoferrin (bLF) typically involves using large amounts of concentrated eluents, which might introduce impurities to the final product. Sometimes, protein pre-concentration is required for the greater accuracy of experimental results. In this research, the supplied bLF sample was subjected to additional ultrafiltration (UF) to eliminate possible small impurities, such as salts and peptides of bLF. Beforehand, the basic characterization of native bLF, including surface-charge properties and the structural sensitivity to the various pH conditions, was performed. The study aimed to evaluate the difference in molecular mass, primary structure, surface morphology, and elemental composition of the protein before and after UF. The research was provided by application of spectroscopic, spectrometric, electrophoretic, and microscopic techniques. The evident changes in the surface morphology of bLF were observed after UF, while the molecular masses of both proteins were comparable. According to MALDI-TOF/MS results, UF had a positive impact on the bLF sample representation, improving the identification parameters, such as sequence coverage and intensity coverage.

A high-throughput differential scanning fluorimetry method for rapid detection of thermal stability and iron saturation in lactoferrin

Thermal stability and iron saturation of lactoferrin (LF) are of great significance not only for the evaluation of the biological activities of LF but also for the optimization of the isolation and drying process parameters. Differential scanning calorimetry (DSC) is a well-established and efficient method for thermal stability and iron saturation detection in LF. However, multiple DSC measurements are typically performed sequentially, thus time-consuming and low throughput. Herein, we introduced the differential scanning fluorimetry (DSF) approach to overcome such limitations. The DSF can monitor LF thermal unfolding with a commonly available real-time PCR instrument and a fluorescent dye (SYPRO orange or Glomelt), and the measured melting temperature of LF is consistent with that determined by DSC. On the basis of that, a new quantification method was established for determination of iron saturation levels using the linear correlation of the degree of ion saturation of LF with DSF measurements. Such DSF method is simple, inexpensive, rapid (<15 min), and high throughput (>96 samples per experiment), and provides a valuable alternative tool for thermal stability detection of LF and other whey proteins.

The essential oil of Melaleuca alternifolia incorporated into hydrogel induces antimicrobial and anti-inflammatory effects on infected wounds by Staphylococcus aureus

Staphylococcus aureus is one of the most common bacterial isolates found in wounds. Thus, innovative dressings, such as hydrogels, are interesting vehicles for incorporating bioactive compounds like those from Melaleuca alternifolia essential oil (MaEO). In this study, we evaluated the antimicrobial and anti-inflammatory potential of MaEO incorporated into an alginate and chitosan hydrogel for treating wounds infected by S. aureus. The hydrogel incorporated with MaEO 1% (HMa 1%) was homogeneous with a bright pale-yellow color and the characteristic smell of Melaleuca. The incorporation of MaEO 1% does not affect the stability of the hydrogel, which was stable up to 90 days of storage. The Scanning electron microscopy analysis revealed that hydrogels showed irregular surfaces and interconnected porous structures with accumulations of oil crystals distributed throughout the formulation. HMa 1% has a high moisture content (95.1%) and can absorb simulated wound fluid. Regarding the antimicrobial effects, HMa 1% reduced the growth of S. aureus ATCC 6538 in both in vitro conditions and in an ex vivo model of wounds using porcine skin. In addition, the dairy topical treatment of murine skin lesions with HMa 1% induced a significant reduction of the wound area, inflammation score, and bacterial load, as well as tissue re-epithelialization and modulation of inflammatory mediators. Therefore, hydrogel incorporated with MaEO 1% has excellent potential to be used in the pharmacotherapy of infected wounds.

Encapsulation and stabilization of lactoferrin in polyelectrolyte ternary complexes

Effective delivery of the bioactive protein, lactoferrin (LF), remains a challenge as it is sensitive to environmental changes and easily denatured during heating, restricting its application in functional food products. To overcome these challenges, we formulated novel polyelectrolyte ternary complexes of LF with gelatin (G) and negatively charged polysaccharides, to improve the thermal stability of LF with retained antibacterial activity. Linear, highly charged polysaccharides were able to form interpolymeric complexes with LF and G, while coacervates were formed with branched polysaccharides. A unique multiphase coacervate was observed in the gum Arabic GA-LF-G complex, where a special coacervate-in-coacervate structure was found. The ternary complexes made with GA, soy soluble polysaccharide (SSP), or high methoxyl pectin (HMP) preserved the protein structures and demonstrated enhanced thermal stability of LF. The GA-LF-G complex was especially stable with >90% retention of the native LF after treatment at 90 °C for 2 min in a water bath or at 145 °C for 30 s, while the LF control had only ~ 7% undenatured LF under both conditions. In comparison to untreated LF, LF in ternary complex retained significant antibacterial activity on both Gram-positive and Gram-negative bacteria, even after heat treatment. These ternary complexes of LF maintain the desired functionality of LF, thermal stability and antibacterial activity, in the final products. The ternary complex structure, particularly the multiphase coacervate, may serve as a template for the encapsulation and stabilization of other bioactives and peptides.

Biogenic engineered nanomaterials for enhancing bioavailability via developing nano-iron-fortified smart foods: advances, insight, and prospects of nanobionics in fortification of food

Iron deficiency is a significant cause of iron deficiency anemia (IDA). Treatment of IDA is challenging due to several challenges, including low target bioavailability, low palatability, poor pharmacokinetics, and extended therapeutic regimes. Nanotechnology holds the promise of revolutionizing the management and treatment of IDA. Smart biogenic engineered nanomaterials (BENMs) such as lipids, protein, carbohydrates, and complex nanomaterials have been the subject of extensive research and opened new avenues for people and the planet due to their enhanced physicochemical, rheological, optoelectronic, thermomechanical, biological, magnetic, and nutritional properties. Additionally, they show eco-sustainability, low biotoxicity, active targeting, enhanced permeation and retention, and stimuli-responsive characteristics. We examine the opportunities offered by emerging smart BENMs for the treatment of iron deficiency anemia by utilizing iron-fortified smart foods. We review the progress made so far and other future directions to maximize the impact of smart nanofortification on the global population. The toxicity effects are also discussed with commercialization challenges.

Tea Tree Oil Nanoemulsion-Based Hydrogel Vehicle for Enhancing Topical Delivery of Neomycin

The present investigation aims to improve the antimicrobial influence of certain antibacterial drugs, namely, neomycin (NEO), exploiting the benefits of natural oils such as tea tree oil (TTO). Therefore, a distinctive nanolipid formulation, namely, a nanoemulsion (NE), was developed using a Central Composite Factorial Design (CCD) approach depending on the amount of TTO and tween 80 as surfactant. The optimized NEO-NE formula exhibiting minimum globular size and maximum in vitro release was selected. For efficient topical delivery, NEO-NE was incorporated into a pre-formulated hydrogel. The developed NEO-NE-hydrogel was characterized by its physical characteristics such as pH, viscosity, and spreadability. Next, it was tested for stability under different conditions for 3 months. Ultimately, an irritation test was conducted followed by an antibacterial examination. The preparation demonstrated acceptable properties to be successfully applied topically. It showed non-significant changes in stability in both conditions up to 3 months storage when compared to a fresh preparation. It exhibited no irritation when applied on hairless animal skin. Finally, TTO revealed a good inhibition for the bacterial growth that could improve the influence of NEO antibacterial activity, indicating the efficiency of NE containing NEO prepared with TTO to be a promising antibacterial nanocarrier.