Food liposomes: Structures, components, preparations, and applications

Critical Review of Food Colloidal Delivery System for Bioactive Compounds: Physical Characterization and Application

Bioactive compounds (BACs) have attracted much attention due to their potential health benefits. However, such substances have problems such as difficulty dissolving in water, poor stability, and low intestinal absorption, leading to serious limitations in practical applications. Nowadays, food colloidal delivery carriers have become a highly promising solution due to their safety, controllability, and efficiency. The use of natural macromolecules to construct delivery carriers can not only regulate the solubility, stability, and intestinal absorption of BACs but also effectively enhance the nutritional added value of functional foods, improve sensory properties, and extend shelf life. Moreover, smart-responsive colloidal delivery carriers can control the release characteristics of BACs, thus improving their absorption rate in the human body. This review describes the characteristics of several typical food colloid delivery carriers, focuses on their physical properties from static structure to dynamic release, summarizes their applications in delivery systems, and provides an outlook on the future development of food colloid delivery carriers. The different compositions and structures of food colloids tend to affect their stability and release behaviors, and the different surface properties and rheological characteristics of the carriers predestine their different application scenarios. The control of in vivo release properties and the effect on food media should be emphasized in the future exploration of safer and more controllable carrier systems.

In Vitro Antioxidant Activity of Liposomal Formulations of Sea Buckthorn and Grape Pomace

This study evaluated the impact of the encapsulation of sea buckthorn and grape pomace extracts in liposomal formulations on the retention and release of bioactive compounds and their antioxidant activity. The profile and composition of lipophilic extracts of sea buckthorn and hydrophilic extracts of grape pomace were analyzed. Encapsulation efficiency, retention rate, and the content of bioactive compounds encapsulated in liposomal formulations prepared in two media-water and ethanol-were evaluated. The encapsulation efficiency varied between 84 and 90%, indicating the superior encapsulation of the bioactive compounds. The retention rate varied between 79 and 86%, which indicated the stability of the liposome-encapsulated compounds over time. The antioxidant activity of the encapsulated samples was determined in vitro, under the conditions of gastric (pH 1.8) and intestinal (pH 8.2) digestion, in relation to the non-encapsulated extracts. The antioxidant activity of both liposomal formulations was higher than that of the nonencapsulated extracts during gastric digestion. Moreover, an increase over time in the antioxidant activity, expressed as % DPPH inhibition, was observed for all samples, with around 90% DPPH inhibition for non-encapsulated extracts and 92% for the encapsulated extracts, demonstrating the stability of bioactive compounds in acidic pH. Oppositely, when exposed to intestinal simulated digestion (alkaline pH), the antioxidant activity decreased over time to around 24% DPPH inhibition for both encapsulated and nonencapsulated extracts. These results provide a foundation for the further development and application of liposomal delivery systems in functional foods.

Potential application of nanoliposomes loaded with complex tannins from the seed shell of Euryale ferox in the anti-browning of fresh-cut asparagus lettuce

Surface browning of plant-derived fresh-cut products is mainly caused by conversion of the phenolic compounds into o-quinones under tyrosinase catalysis. In this study, the rarely reported complex tannins from Euryale ferox seed shell (ECTs) constituted by the units of 35.60% condensed tannins and 64.40% hydrolysable tannins were shown to suppress the activity of tyrosinase efficiently, supporting the exploitation of ECTs into novel anti-browning agents. However, the utilization of ECTs in food preservation is often restricted because of their chemical instability to external environment. Further fabrication of nanoliposomes loaded with ECTs (ECTs-NLs) herein was carried out to improve the stability of ECTs. DLS, TEM, FTIR, DSC and XRD confirmed that ECTs were encapsulated into nanoliposomes successfully, and ECTs-NLs appeared as vesicle-like spherical morphology with favorable encapsulation efficiency, uniform particle size distribution and negative zeta-potential. The resulting ECTs-NLs were relatively stable in the dark at 4 °C. Nanoliposomal encapsulation significantly enhanced ECTs stability, thus protecting inhibitory effect of ECTs against tyrosinase. Furthermore, anti-browning evaluation proved that ECTs-NLs had distinct advantages over free ECTs in alleviating surface browning of fresh-cut asparagus lettuces. These results suggested that nanoliposomes were effective in stabilizing ECTs and ECTs-NLs could be potentially applied to the fresh-cut food industry.

Preparation, characterization, in vitro and in vivo studies of liposomal berberine using novel natural fiber Interlaced liposomal technology

Berberine hydrochloride (BBR), used in various traditional medicinal practices, has a variety of pharmacological effects. It is a plant-derived quaternary isoquinoline alkaloid with a low water solubility that may be used in the treatment of conditions such as hypercholesterolemia. However, the therapeutic use of BBR has been compromised because of its hydrophobic characteristics, in addition to its low stability and poor bioavailability. To overcome these drawbacks of BBR's oral bioavailability, technologies like liposomal delivery systems have been developed to ensure enhanced absorption. But conventional liposomes have low physical and chemical stability due to delicate liposomal membranes, peroxidation and rapid clearance from the bloodstream. Surface modification of liposomes could be a solution and creating a liposome with plant-based fibers as surface material will provide enhanced stability, aqueous solubility and protection against degradation. Consequently, the aim of this study is to create and describe a Fiber Interlaced Liposome™ (FIL) as a vehicle for an enhanced bioavailability platform for BBR and other biomolecules. This optimised FIL-BBR formulation was analysed for its structural and surface morphological characteristics by using FTIR, SEM, TEM, XRD, zeta potential and DSC. Encapsulation efficiency, stability, and sustained release studies were done using an in vitro digestion model with simulated gastric and intestinal fluids. FIL formulation showed a sustained release of BBR at 59.03 % as compared to the unformulated control (46.73 %) after 8 h of dialysis. Furthermore, the FIL-BBR demonstrated enhanced stability in the simulated gastric fluid (SGF) in addition to a more sustained release in the simulated intestinal fluid (SIF). The efficacy of FIL-BBR were further anlaysed by an in vivo bioavailability study using male Wistar rats and it demonstrated a 3.37 -fold higher relative oral bioavailability compared to the unformulated BBR. The AUC 0-t for BBR in FIL-BBR was 1.38 ng.h/mL, significantly greater than the unformulated BBR (0.041 ng.h/mL). Similarly, the Cmax for BBR in FIL-BBR (50.98 ng/mL) was discovered to be far greater than unformulated BBR (15.54 ng/mL) after the oral administration. These findings imply that fiber based liposomal encapsulation improves the stability and slows down BBR release, which could be advantageous for applications requiring a higher bioavailability and a more sustained release.

A Multifunctional Nanocomposite Hydrogel Delivery System Based on Dual-Loaded Liposomes for Scarless Wound Healing

Increased inflammatory responses and oxidative stress at the wound site following skin trauma impair healing. Furthermore, skin scarring places fibroblasts under severe mechanical stress and aggravates pathological fibrosis. A novel liposomal composite hydrogel is engineered for wound microenvironment remodeling, incorporating dual-loaded liposomes into gelatin methacrylate to create a nanocomposite hydrogel. Notably, tetrahydrocurcumin (THC) and hepatocyte growth factor (HGF) are encapsulated in the hydrophobic and hydrophilic layers of liposomes, respectively. The composite hydrogel maintains porous nanoarchitecture, demonstrating sustainable THC and HGF release and enhanced mechanical properties and biocompatibility. This system effectively promotes cell proliferation and angiogenesis and attenuates apoptosis. It decreases the expression of the inflammatory factors by inhibiting the high-mobility group box /receptor for advanced glycation end product/NF-κB (HMGB1/RAGE/NF-κB)pathway and increases macrophage polarization from M1 to M2 in vitro, effectively controlling inflammatory responses. It exhibits remarkable antioxidant properties by scavenging excess reactive oxygen species and free radicals. Most importantly, it effectively prevents scar formation by restraining the transforming growth factor beta (TGF-β)/Smads pathway that downregulates associated fibrotic factors. It demonstrates strong therapeutic effects against inflammation and fibrosis in a rat skin wound model with biosafety, advancing the development of innovative hydrogel-based therapeutic delivery strategies for clinical scarless wound therapy.

Liposomes against Alzheimer's Disease: Current Research and Future Prospects

Alzheimer's disease, the most common neurodegenerative disease, affects more than 60 million people worldwide, a number that is estimated to double by 2050. Alzheimer's disease is characterized by progressive memory loss, the impairment of behavior, and mood changes, as well as the disturbed daily routine of the patient. Although there are some active molecules that can be beneficial by halting the progression of the disease, the blood-brain barrier and other physiological barriers hinder their delivery and, consequently, the appropriate management of the disease. Therefore, drug delivery systems that effectively target and overcome the blood-brain barrier to reach the targeted brain area would improve treatment effectiveness. Liposomes are lipophilic carriers that consist of a phospholipid bilayer structure, simulating the physiological lipidic layer of the blood-brain barrier and enabling better delivery of the drug to the brain. Given that pure liposomes may have less targeting affinity than functionalized liposomes, modification with groups such as lactoferrin, poly(ethylene glycol), and transferrin may improve specificity. In this mini-review, we summarize the literature on the use of liposomes for the treatment of Alzheimer's disease, focusing on the functionalization moieties of liposomes. In addition, challenges in brain delivery are also discussed.

Liposomes as Carriers of Bioactive Compounds in Human Nutrition

This article provides an overview of the literature data on the role of liposomal structures and encapsulated substances in food technology and human nutrition. The paper briefly describes how liposomes are created and how they encapsulate food ingredients, which can either be individual compounds or plant extracts. Another very interesting application of liposomes is their use as antimicrobial carriers to protect food products from spoilage during storage. The encapsulation of food ingredients in liposomes can increase their bioavailability, which is particularly important for compounds with health-promoting properties but low bioavailability. Particular attention was paid to compounds such as phytosterols, which lower blood cholesterol levels but have very low absorption in the human body. In addition, consumer expectations and regulations for liposomes in food are discussed. To date, no in vivo human studies have been conducted to indicate which encapsulation methods give the best results for gastrointestinal effects and which food-added substances are most stable during food storage and processing. The paper identifies further lines of research that are needed before liposomes can be introduced into food.

Construction Strategy of Functionalized Liposomes and Multidimensional Application

Liposomes are widely used in the biological field due to their good biocompatibility and surface modification properties. With the development of biochemistry and material science, many liposome structures and their surface functional components have been modified and optimized one by one, pushing the liposome platform from traditional to functionalized and intelligent, which will better satisfy and expand the needs of scientific research. However, a main limiting factor effecting the efficiency of liposomes is the complicated environmental conditions in the living body. Currently, in order to overcome the above problem, functionalized liposomes have become a very promising strategy. In this paper, binding strategies of liposomes with four main functional elements, namely nucleic acids, antibodies, peptides, and stimuli-responsive motif have been summarized for the first time. In addition, based on the construction characteristics of functionalized liposomes, such as drug-carrying, targeting, long-circulating, and stimulus-responsive properties, a comprehensive overview of their features and respective research progress are presented. Finally, the paper critically presents the limitations of these functionalized liposomes in the current applications and also prospectively suggests the future development directions, aiming to accelerate realization of their industrialization.

Self-Assembled Nanocarrier Delivery Systems for Bioactive Compounds

Although bioactive compounds (BCs) have many important functions, their applications are greatly limited due to their own defects. The development of nanocarriers (NCs) technology has gradually overcome the defects of BCs. NCs are equally important as BCs to some extent. Self-assembly (SA) methods to build NCs have many advantages than chemical methods, and SA has significant impact on the structure and function of NCs. However, the relationship among SA mechanism, structure, and function has not been given enough attention. Therefore, from the perspective of bottom-up building mechanism, the concept of SA-structure-function of NCs is emphasized to promote the development of SA-based NCs. First, the conditions and forces for occurring SA are introduced, and then the SA basis and molecular mechanism of protein, polysaccharide, and lipid are summarized. Then, varieties of the structures formed based on SA are introduced in detail. Finally, facing the defects of BCs and how to be well solved by NCs are also elaborated. This review attempts to describe the great significance of constructing artificial NCs to deliver BCs from the aspects of SA-structure-function, so as to promote the development of SA-based NCs and the wide application of BCs.

Advances in encapsulation systems of Antarctic krill oil: From extraction to encapsulation, and future direction

Antarctic krill oil (AKO) is highly sought after by consumers and the food industry due to its richness in a variety of nutrients and physiological activities. However, current extraction methods are not sufficient to better extract AKO and its nutrients, and AKO is susceptible to lipid oxidation during processing and storage, leading to nutrient loss and the formation of off-flavors and toxic compounds. The development of various extraction methods and encapsulation systems for AKO to improve oil yield, nutritional value, antioxidant capacity, and bioavailability has become a research hotspot. This review summarizes the research progress of AKO from extraction to encapsulation system construction. The AKO extraction mechanism, technical parameters, oil yield and composition of solvent extraction, aqueous enzymatic extraction, supercritical/subcritical extraction, and three-liquid-phase salting-out extraction system are described in detail. The principles, choice of emulsifier/wall materials, preparation methods, advantages and disadvantages of four common encapsulation systems for AKO, namely micro/nanoemulsions, microcapsules, liposomes and nanostructured lipid carriers, are summarized. These four encapsulation systems are characterized by high encapsulation efficiency, low production cost, high bioavailability and high antioxidant capacity. Depending on the unique advantages and conditions of different encapsulation methods, as well as consumer demand for health and nutrition, different products can be developed. However, existing AKO encapsulation systems lack relevant studies on digestive absorption and targeted release, and the single product category of commercially available products limits consumer choice. In conjunction with clinical studies of AKO encapsulation systems, the development of encapsulation systems for special populations should be a future research direction.

Influence of Auricularia cornea Polysaccharide Coating on the Stability and Antioxidant Activity of Liposomes Ginsenoside Rh2

Liposomes (Lip) are microstructures containing lipid and aqueous phases for encapsulation and delivery of bioactivators. In this study, Ginsenoside Rh2 liposomes (Rh2-Lip) were prepared by a thin-film hydrated ultrasonic binding method. But they are not stable during storage. In addition, Rh2-Lip was wrapped with Auricultural cornea polysaccharide (ACP) and Chitosan (CS) as coating materials to improve stability. CS coating was used as a positive control. The particle sizes determined by dynamic light scattering (DLS) showed 183 ± 5.52 nm for liposomes, 197 ± 6.7 nm for Auricultural cornea polysaccharide coated liposomes (ACP-Rh2-Lip), and 198 ± 3.5 nm for Chitosan coated liposomes (CS-Rh2-Lip). The polydispersity index (PDI) of all liposomes was less than 0.3. Transmission electron microscopy (TEM) showed that ACP and CS were successfully encapsulated on the liposome surface. In vitro simulations of digestive stability in the gastrointestinal tract showed that ACP-Rh2-Lip and CS-Rh2-Lip were more stable in gastrointestinal fluids compared to Lip. The antioxidant experiment revealed that ACP-Rh2-Lip has greater antioxidant activity than Lip. The purpose of this study was to look into the effects of ACP-Rh2-Lip and to offer a reference for Ginsenoside Rh2 (Rh2) delivery.