Stability and catalytic kinetics of protease loaded liposomes

Liposome vesicle cannot be formed in non-aqueous phase

In the February of 2023, Yang et al., report a paper to unreal mechanisms of protein and lipid oxidation in mayonnaise with claim of liposome formation in Mayonaise. As bilayer liposome has spherical or oval like structure composed bilayers separated by aqueous region, there is doubt for formation possibility of liposome in non-aqueous phase. In this bilayer vesicle a hydrophobic layer has been replaced between two outer and inner hydrophilic molecules, so regarding thermodynamic rules for tendency to a minimum enthalpy formation of bilayer vesicle with a hydrophobic outer layer in Mayonaise matrix is not possible. It seems more likely the micelle structure instead of liposome. The images in the article is indeed hard to see a liposomal bilayer structure. In other case, more explanation and evidences are required to clarify ambiguous points in this claim. So, arrangement of self-assembling of water soluble phospholipid may occur just in aqueous phase liposome formation is not possible. Also no document exists for bilayer of vesicles. So, those formed vesicle could be reverse micelle not liposome which usually form following dispersion of phospholipids in aqueous phase.

Enhancement of the anti-microbial activity of Mentha spicata essential oil on storage by glycerosomes

Mentha spicata essential oil (EO) is isolated from the aerial parts of Mentha spicata L. with pronounced antibacterial effects as food preservative in food industry. Nevertheless, its application in the clinical industry and food is significantly restricted by its poor water solubility and physicochemical instability. Glycerosomes of this EO were prepared to enhance its anti-microbial stability. The EO was encapsulated in the glycerosomes and characterized for its physical properties. The optimized EO-loaded glycerosomes displayed entrapment efficiency of 93.2 ± 7.5%, release efficiency of 75.4 ± 6.1%, the particle size of 276 nm, and zeta potential of - 30.4 mV. Scanning electron microscopy (SEM) image showed spherical morphology of the glycerosomes. EO release from optimized formulation of glycerosomes best fitted with a first-order kinetic model. Compared with free EO, EO-loaded glycerosomes showed better storage stability. The results indicated that the incorporation of EO in glycerosomes possessed sustained release properties and significantly enhanced antibacterial effects in storage.

Microencapsulation of a Commercial Food-Grade Protease by Spray Drying in Cross-Linked Chitosan Particles

In this study, the use of spray-drying technology for encapsulating Flavourzyme® (protease–peptidase complex) was evaluated to overcome the limitations (low encapsulation efficiency and no large-scale production) of other encapsulation processes. To the best of our knowledge, spray drying has not been applied previously for the immobilization of this enzyme. Firstly, bovine serum albumin (BSA), as a model protein, was encapsulated by spray drying in chitosan and tripolyphoshate (TPP) cross-linked-chitosan shell matrices. The results showed that the chitosan–TPP microcapsules provided a high encapsulation efficiency and better protein stability compared to the non-crosslinked chitosan microcapsules. The effect of enzyme concentration and drying temperature were tested during the spray drying of Flavourzyme®. In this regard, an activity yield of 88.0% and encapsulation efficiency of 78.6% were obtained with a concentration of 0.1% (v/v) and an inlet temperature of 130 °C. Flavourzyme®-loaded chitosan microcapsules were also characterized in terms of their size and morphology using scanning electron microscopy and laser diffractometry.

Entrapment of rosemary extract by liposomes formulated by Mozafari method: physicochemical characterization and optimization

A major obstacle in the utilization of phenolic antioxidant compounds is their sensitivity and as a result stability issue. The current study aimed to encapsulate polyphenolic compounds, extracted from Rosemary, in liposomes prepared by the Mozafari method without the utilization of toxic solvents or detergents. The extract was prepared and converted into a powder by freeze-drying. The process conditions were optimized using response surface analysis, and the optimal parameters were as follows: phosphatidylcholine (PC), 2.5% (25 mg/mL); extract, 0.7% (7 mg/mL); process temperature, 70 °C and process time, 60 min. The entrapment efficiency in optimal sample was 54.59%. Also, optimal glycerosomes formulation were finally physicochemical characterized (permeability, zeta potential, and size distribution). The mean size of empty and containing rosemary extract glycerosome were 265.4 nm and 583.5 nm, respectively, and the Z-potential of optimal glycerosome was -65.1 mV. Total phenolic content was obtained 151.38 mg gallic acid/g extract, in optimal liposomal formulation, which was measured by Folin-Ciocalteu's phenol reagent. Also, the antioxidant activity of rosemary extract by DPPH for the free and optimal liposomal formulation was determined to be 84.57% and 92.5% respectively. It can be concluded that the liposomal rosemary extract formulation prepared in this study, employing a safe, scalable, and green technology, has great promise in food and pharmaceutical applications.