One-pot nanoparticulation of potentially bioactive peptides and gallic acid encapsulation

In Vitro Antibacterial and Wound Healing Activities Evoked by Silver Nanoparticles Synthesized through Probiotic Bacteria

The prospective application of probiotics is an adjuvant for the advancement of novel antimicrobial and wound-healing agents. Currently, probiotic bacteria are utilized for the biosynthesis of nanoparticles in the development of innovative therapeutics. The present study aimed at using nanoparticle-conjugated probiotic bacteria for enhanced antibacterial and wound-healing activity. In the present investigation, the probiotic bacteria were isolated from a dairy source (milk from domestic herbivores). They screened for antibacterial activity against infection-causing Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Bacillus subtilis and Staphylococcus aureus) pathogens. Further, the probiotic strain with higher bactericidal activity was used to synthesize silver, selenium, and copper nanoparticles. The isolated strain was found to be Lactiplantibacillus plantarum and it only has the ability to synthesize silver nanoparticles. This was verified using Ultra violet-Visible (UV-Vis) spectroscopy, where the test solution turned brown and the greatest UV-Vis absorptions peaked at 425 nm. Optimization studies on the synthesis of AgNPs (silver nanoparticles) are presented and the results show that stable synthesis was obtained by using a concentration of 1mM silver nitrate (AgNO₃) at a temperature of 37 °C with pH 8. The FTIR (Fourier transform infrared spectroscopy) study confirmed the involvement of functional groups from the cell biomass that were involved in the reduction process. Additionally, biosynthesized AgNPs showed increased antioxidant and antibacterial activities. The nano silver had a size distribution of 14 nm and was recorded with HR-TEM (high-resolution transmission electron microscopy) examination. The EDX (energy dispersive X-ray) analysis revealed 57% of silver groups found in the nanoparticle production. The biosynthesized AgNPs show significant wound-healing capabilities with 96% of wound closure (fibroblast cells) being observed through an in vitro scratch-wound assay. The cytotoxic experiments demonstrated that the biosynthesized AgNPs are not extremely hazardous to the fibroblast cells. The present study provides a new platform for the green synthesis of AgNPs using probiotic bacteria, showing significant antibacterial and wound-healing potentials against infectious pathogens.

Strategies for Improving Bioavailability, Bioactivity, and Physical-Chemical Behavior of Curcumin

Curcumin (CCM) is one of the most frequently explored plant compounds with various biological actions such as antibacterial, antiviral, antifungal, antineoplastic, and antioxidant/anti-inflammatory properties. The laboratory data and clinical trials have demonstrated that the bioavailability and bioactivity of curcumin are influenced by the feature of the curcumin molecular complex types. Curcumin has a high capacity to form molecular complexes with proteins (such as whey proteins, bovine serum albumin, β-lactoglobulin), carbohydrates, lipids, and natural compounds (e.g., resveratrol, piperine, quercetin). These complexes increase the bioactivity and bioavailability of curcumin. The current review provides these derivatization strategies for curcumin in terms of biological and physico-chemical aspects with a strong focus on different type of proteins, characterization methods, and thermodynamic features of protein–curcumin complexes, and with the aim of evaluating the best performances. The current literature review offers, taking into consideration various biological effects of the CCM, a whole approach for CCM-biomolecules interactions such as CCM-proteins, CCM-nanomaterials, and CCM-natural compounds regarding molecular strategies to improve the bioactivity as well as the bioavailability of curcumin in biological systems.

Preparation, characterization, and antioxidant activity of zein nanoparticles stabilized by whey protein nanofibrils

The application of natural biopolymers to develop colloidal carriers for delivering hydrophobic bioactive molecules has become one of the hottest topics in food science. In this study, a simple pH-driven method to prepare whey protein nanofibrils stabilized zein nanoparticles was developed. The formation, structure, intermolecular interactions, rheological properties, in vitro digestion, and antioxidant activity of the nanoparticles were investigated. When the mass ratio of zein and whey protein nanofibrils was 1:0.8, the hydrodynamic diameter and zeta potential of the nanoparticles were 413 nm and - 25 mV, respectively. Transmission electron microscope photographs showed that the nanoparticles were a spherical core-shell structure. Fourier transform infrared spectroscopy and surface hydrophobicity measurements indicated that whey protein nanofibrils adsorbed to the surface of zein aggregates through hydrogen bonding and hydrophobic interactions. Differential scanning calorimetry tests confirmed the formation of nanoparticles improved the thermal stability of zein and whey protein nanofibrils. The nanoparticles exhibited less shear-thinning behavior with low apparent viscosity, and it can't be degraded in simulated gastric fluid but can be in simulated intestinal fluid. The antioxidant activity of the nanoparticles was increased by in vitro antioxidant assay when compared to whey protein nanofibrils. This new technology to develop zein-whey protein nanoparticles may be used for preparing nanoparticles of other similar hydrophobic food ingredients. And the findings of this study may provide a theoretical basis for preparation of nanoparticles as a nutrient delivery system.

Eco Friendly Approach for Synthesis, Characterization and Biological Activities of Milk Protein Stabilized Silver Nanoparticles

Today, the overall occurrence of re-emerging and rising illnesses has been a serious load on economies as well as public health. Here, we describe a simple, nontoxic and eco-friendly method for the synthesis of milk protein (MP)-stabilized silver nanoparticles (MP-s-AgNPs) using ultrahigh-temperature full cream milk. Highly stable AgNPs were prepared with a fair control over their size, without using any reducing or stabilizing agent, and their formation was attributed to the presence of the MP casein. Ag⁺ ion reduction was possibly caused by the MPs. The synthesized MP-s-AgNPs were characterized in detail by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and dynamic light scattering. MP-s-AgNPs showed inhibitory activity against both Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative microorganisms (Salmonella typhi and Escherichia coli). Moreover, MP-s-AgNPs were found to be more toxic to bacteria than to fungi (Aspergillus fumigatus, Aspergillus ochraceus and Penicillium chrysogenum).

Soymilk-Cow's milk ACE-inhibiting enzyme modified cheese

In present study, we developed and optimized soymilk-cow's milk enzyme-modified cheese with angiotensin-I converting enzyme inhibitory activity. Bioactive peptide production was found to be a multivariable-dependent process. Maximum bioactivity of hydrolysates was obtained with prolonged curd proteolysis at an increased enzyme concentration. This bioactive cheese paste was subsequently spray-dried under different drying conditions to determine the powder sorption isotherm properties. Higher drying temperatures resulted in cheese powder with weak thermal stability and lower browning indices. Experiments aimed at optimizing thermal stability and physical properties revealed that optimal conditions for producing cheese powder were an inlet air temperature of 150°C, a feeding rate of 10%, and an air flow rate of 600Lh^-1. Moreover, in addition to flavour, the bioactive cheese powders produced from a combination of soymilk-cow's milk are of potential source and can be used in the dietary management of hypertension.

Functional and in vitro gastric digestibility of the whey protein hydrogel loaded with nanostructured lipid carriers and gelled via citric acid-mediated crosslinking

Nanostructured lipid carriers (NLCs) with mean size of 347nm were fabricated and added into a heat-denatured whey protein solution. The subsequent crosslinking of proteins by citric acid or CaCl₂ resulted in the formation of cold-set hydrogels. Fourier transform infrared spectroscopy (FTIR) proposed formation of more hydrogen bonds in gel due to NLC loading or citric acid-mediated gelation. It was also found based on FITR spectroscopy that citric acid crosslinking disordered whey proteins. Scanning electron microscopy (SEM) imaging showed a non-porous and finely meshed microstructure for the crosslinked gels compared to non-crosslinked counterparts. Crosslinking also increased the firmness and water-holding capacity of gels. In pepsin-free fluid, a strong correlation existed between reduction in gel swellability and digestibility over periods up to 60min due to NLC loading and citric acid gelation. However, in peptic fluid, NLC loading and citric acid crosslinking brought about much higher decrease in digestibility than swellability.