The influence of sodium alginate and genipin on physico-chemical properties and stability of WPI coated liposomes

Liposomes decorated with β-conglycinin and glycinin: Construction, structure and in vitro digestive stability

Liposomes were modified with different proportions of β-conglycinin (7S) and glycinin (11S) to form Lip-7S and Lip-11S. The morphology, interaction and in vitro simulated digestion of liposomes were studied. The particle size of Lip-7S was smaller than that of Lip-11S. When the values of Lip-7S and Lip-11S were 1:1 and 1:0.75, respectively, the ζ-potential had the maximum absolute value and the dispersion of the system was good. The results of multispectral analysis showed that hydrogen-bond and hydrophobic interaction dominated protein-modified liposomes, the protein structure adsorbed on the surface of liposomes changed, the content of α-helix decreased, and the structure of protein-modified liposomes became denser. The surface hydrophobicity and micropolarity of liposomes decreased with the increase of protein ratio, and tended to be stable after Lip-7S (1:1) and Lip-11S (1:0.75). Differential scanning calorimetry showed that Lip-7S had higher phase transition temperature (≥170.5 °C) and better rigid structure. During simulated digestion, Lip-7S (22.5 %) released less Morin than Lip (40.6 %) and Lip-11S (26.2 %), and effectively delayed the release of FFAs. The environmental stability of liposomes was effectively improved by protein modification, and 7S had better modification effect than 11S. This provides a theoretical basis for 7S and 11S modified liposomes, and also provides a data reference for searching for new materials for stabilization of liposomes.

Techniques, applications and prospects of polysaccharide and protein based biopolymer coatings: A review

The growing relevance of sustainable materials has recently led to the exploration of naturally derived biopolymeric hydrogels as coating materials due to their biodegradability, biocompatibility, ease of fabrication and modification. Although many review articles exist on biopolymeric coatings, they mainly focus on a specific polysaccharide, protein biopolymer, or a particular application- biomedical engineering or food preservation. The current review first summarizes the commonly used polysaccharide and protein-based biopolymers like chitosan, alginate, carrageenan, pectin, cellulose, starch, pullulan, agarose and silk fibroin, gelatin, respectively, with a systematic description of the techniques widely used for physical coating on substrates. Then, broad applications of these biopolymeric coatings on various substrates in biomedical engineering- 3D scaffolds, biomedical implants, and nanoparticles are described in detail. It also entails the application of biopolymeric coatings for food preservation in the form of food packaging and edible coatings. A brief discussion on the newly discovered interest in exploring biopolymers for anticorrosive coating applications is also included. Finally, concluding remarks on the role of biopolymer microstructures in forming homogeneous coatings, prospective alternatives to the currently used biopolymers as coating material and the advent of computer-aided technologies to expedite experimental findings are presented.

Stability and cytotoxicity of biopolymer-coated liposomes for use in the oral cavity

This study investigates the stability and cytotoxicity of biopolymer-coated liposomes for use in the oral cavity. Liposomes (3 mM and 6 mM) were prepared by the thin film method and hydrated with phosphate buffer (PB) or glycerol phosphate buffer (G-PB). For coating, liposomes were added to a biopolymer solution of opposite charge. Particle stability was evaluated by measuring the size, polydispersity index, and zeta potential for up to 60 weeks. In vitro interaction of fluorescent-labelled biopolymer-coated liposomes and dysplastic oral keratinocytes was analyzed by confocal microscopy. Potential cytotoxicity was assessed in dysplastic oral keratinocytes by cell proliferation and cell viability. All three biopolymers showed good coating abilities for both concentrations and hydration media. The alginate coated liposomes in PB, 3 mM chitosan-coated liposomes in PB, and chitosan-coated liposomes in G-PB were stable for up to 60 weeks. In vitro studies demonstrated low cytotoxicity for all coated liposomes and non-specific cellular uptake of biopolymer-coated liposomes, independent of biopolymer, surface charge, lipid concentration and hydration media. All three formulations demonstrated low cytotoxicity and were considered safe. Alginate- and chitosan-coated liposomes demonstrated good stability over time and may be promising agents for use in the oral cavity and should be investigated further.

Carboxymethyl chitosan coated alpha-linolenic acid nanoliposomes: Preparation, stability and release in vitro and in vivo

Nanoliposome encapsulation combined with carboxymethyl chitosan (CMCS) surface decoration was employed to improve physicochemical stability and oral bioavailability of alpha-linolenic acid (ALA). Different nanoliposome systems including ALA-loaded nanoliposomes (ALA-NLs) and CMCS-coated ALA-NLs (CMCS-ALA-NLs) were characterized through dynamic light scattering, transmission electron microscope, Fourier transform infrared spectroscopy and differential scanning calorimetry. The results showed that CMCS-ALA-NLs had good encapsulation efficiency of 79% and layer formation with nanosized spherical carrier. The physicochemical stability of CMCS-ALA-NLs was better than that of ALA-NLs. CMCS-ALA-NLs were able to regulate the release of ALA in a simulated gastrointestinal environment. In vivo testing found that ALA concentration of CMCS-ALA-NLs had an area under the curve of 1.32, which was 1.28 times higher than that of ALA-NLs and 2 times higher than that of ALA-emulsion. The absorption of ALA was improved by CMCS-ALA-NLs. It suggested that CMCS-coated nanoliposomes should be an available delivery strategy for transporting ALA.

Coating Materials to Increase the Stability of Liposomes

Liposomes carry various compounds with applications in pharmaceutical, food, and cosmetic fields, and the administration route is especially parenteral, oral, or transdermal. Liposomes are used to preserve and release the internal components, thus maintaining the properties of the compounds, the stability and shelf life of the encapsulated products, and their functional benefits. The main problem in obtaining liposomes at the industrial level is their low stability due to fragile phospholipid membranes. To increase the stability of liposomes, phospholipid bilayers have been modified or different coating materials have been developed and studied, both for liposomes with applications in the pharmaceutical field and liposomes in the food field. In the cosmetic field, liposomes need no additional coating because the liposomal formulation is intended to have a fast penetration into the skin. The aim of this review is to provide current knowledge regarding physical and chemical factors that influence stability, coating materials for liposomes with applications in the pharmaceutical and food fields to increase the stability of liposomes containing various sensitive compounds, and absorption of the liposomes and commercial liposomal products obtained through various technologies available on the market.

Liposome and microemulsion loaded with ibuprofen: from preparation to mechanism of drug transport

To compare the difference between liposome (LP) and microemulsion (ME) in delivering ibuprofen (IBU) transdermally and explore relative mechanism. IBU-LP and IBU-ME were prepared by ethanol injection and spontaneous emulsification, respectively. The percutaneous delivery was evaluated using Franz diffusion cells. Fourier transform infra-red spectroscopy (FTIR), differential scanning calorimetry (DSC), activation energy (Ea), and confocal laser scanning microscopy (CLSM) were used to investigate the transdermal mechanism. The particle size and encapsulation efficiency were 228.00 ± 8.60 nm, 86.68 ± 1.43%(w/w) for IBU-LP, and 56.74 ± 7.11 nm, 91.08 ± 3.27%(w/w) for IBU-ME. Percutaneous study showed that formulations enhanced permeation and drug retention in the skin. FTIR and DSC showed that the permeation occurred due to the interaction of the formulations with the lipid bilayer and the protein. The decrease in Ea (1.506 and 0.939 kcal/mol) revealed that the stratum corneum (SC) lipid bilayers were significantly disrupted and this destructive effect of IBU-LP was stronger. IBU-LP was superior to IBU-ME in the aspects of transdermal delivery of IBU.

Stability characterization for pharmaceutical liposome product development with focus on regulatory considerations: An update

Liposomes have several advantages, such as the ability to be employed as a carrier/vehicle for a variety of drug molecules and at the same time they are safe and biodegradable. In the recent times, compared to other delivery systems, liposomes have been one of the most well-established and commercializing drug products of new drug delivery methods for majority of therapeutic applications. On the other hand, it has several limitations, particularly in terms of stability, which impedes product development and performance. In this review, we reviewed all the potential instabilities (physical, chemical, and biological) that a formulation development scientist confronts throughout the development of liposomal formulations as along with the ways to overcome these challenges. We have also discussed the effect of microbiological contamination on liposomal formulations with a focus on the use of sterilization methods used to improve the stability. Finally, we have reviewed quality control techniques and regulatory considerations recommended by the agencies (USFDA and MHLW) for liposome drug product development.

Cationic inulin as a new surface decoration hydrocolloid for improving the stability of liposomal nanocarriers

The aim of the present study was to investigate the cationization of inulin with Williamson's etherification method, and compare cationic inulin with unmodified inulin coatings for stabilizing nanoliposomes (NLPs). The synthetized cationic inulin was characterized by Fourier transforms infrared (FT-IR) spectroscopy, carbon hydrogen nitrogen (CHN) elemental analysis, and energy-dispersive X-ray spectroscopy. Three concentrations of inulin and cationic inulin (1, 2, and 4 mg/mL) were used for the coating of NLPs. The concentration of 4 mg/mL was found to be optimal for inulin and cationic inulin as surface coating, on the basis of particle size, zeta potential, and microstructural morphology. The lowest values of particle size (93.41 nm), polydispersity index (0.25), and negative zeta potential (-24.41 mV) were related to the coated NLPs with cationic inulin at a concentration of 4 mg/mL. The transmission electron microscopy image of the coated NLPs with cationic inulin exhibited a spherical and core-shell structure. The coated NLPs with cationic inulin showed the highest thermal stability, physical stability, and oxidative stability. In conclusion, cationic inulin coating conferred a stronger protection than the unmodified inulin coating of NLPs. The technique developed here can be applied for surface decoration of NLPs to improve their stability.

Protein-polysaccharide interactions for the fabrication of bioactive-loaded nanocarriers: Chemical conjugates and physical complexes

As unique biopolymeric architectures, covalently and electrostatically protein-polysaccharide (PRO-POL) systems can be utilized for bioactive delivery by virtue of their featured structures and unique physicochemical attributes. PRO-POL systems (i. e, microscopic /nano-dimensional multipolymer particles, molecularly conjugated vehicles, hydrogels/nanogels/oleogels/emulgels, biofunctional films, multilayer emulsion-based delivery systems, particles for Pickering emulsions, and multilayer coated liposomal nanocarriers) possess a number of outstanding attributes, like biocompatibility, biodegradability, and bioavailability with low toxicity that qualify them as powerful agents for the delivery of different bioactive ingredients. To take benefits from these systems, an in-depth understanding of the chemical conjugates and physical complexes of the PRO-POL systems is crucial. In this review, we offer a comprehensive study concerning the unique properties of covalently/electrostatically PRO-POL systems and introduce emerging platforms to fabricate relevant nanocarriers for encapsulation of bioactive components along with a subsequent sustained/controlled release.

Coating of betanin and carvone Co-loaded nanoliposomes with synthesized cationic inulin: A strategy for enhancing the stability and bioavailability

Betanin (BET) and carvone (CAR) as antioxidant and antibacterial compounds were co-loaded in the coated nanoliposomes (NLPs) with cationic inulin to improve their stability and bioavailability. A cationic inulin was successfully synthesized and used for surface coating of the NLPs. The zeta potential, particle size, and PDI values of the coated NLPs were 21.70 ± 7.00 mV, 143.5 ± 15.2 nm, and 0.35 ± 0.03 respectively. The encapsulation efficiency values of the coated NLPs for BE and CAR were 86.1 ± 3.9 and 77.2 ± 5.2 %, respectively. Electron microscopy results showed that the coated NLPs had spherical and core-shell structures. The slowest sustained release profile in the simulated gastrointestinal condition was obtained for the coated NLPs. The physical and oxidative stability of NLPs, as well as the physical stability of loaded compounds were improved by surface coating. In conclusion, the developed nanocarrier is a suitable platform to use all benefits of BET and CAR in the food industry.

Alginate-based delivery systems for food bioactive ingredients: An overview of recent advances and future trends

Due to its advantagessuch as ionic crosslinking, pH responsiveness, excellent biocompatibility, biodegradability and low price, alginate has become one of the most important natural polysaccharides extensively used in constructing desired delivery systems for food bioactive ingredients. In this review, the fundamental knowledge of alginate as a building block for construction of nutraceutical delivery systems is introduced. Then, various types of alginate-based nutraceutical delivery systems are classified and summarized. Furthermore, the future trends of alginate-based delivery systems are highlighted. Currently, alginate-based delivery systems include hydrogel, emulsion, emulsion-filled alginate hydrogel, nanoparticle, microparticle, core-shell particle, liposome, edible film, and aerogel. Although alginate has been widely used in the fabrication of food bioactive ingredient delivery systems, further efforts and improvements are still needed. For this purpose, the future perspectives of alginate-based delivery systems are discussed. The feasible research trends of alginate-based delivery systems include the development of novel large-scale commercial preparation technology, multifunctional delivery system based on alginate, alginate oligosaccharide-based delivery system and alginate-based oleogel. Overall, the objective of this review is to provide useful guidance for rational design and application of alginate-based nutraceutical delivery systems in the future.

Food-grade systems for delivery of DHA and EPA: Opportunities, fabrication, characterization and future perspectives

Docosahexaenoic acid (C22: 6n-3, DHA) and eicosapentaenoic acid (C20: 5n-3, EPA) have been shown to provide the opportunity to inhibit onset and escalation of chronic diseases. Nevertheless, their undesirable characteristics including poor water solubility, oxidation sensitivity, high melting point and unpleasant sensory attributes hinder their application in the food industry. In recent years, utilizing food-grade delivery systems to deliver DHA/EPA and improve their biological efficacy has emerged as an attractive approach with fascinating prospects. This review focuses on introducing potential delivery systems for DHA/EPA, including microemulsions, nanoemulsions, Pickering emulsions, hydrogels, lipid particles, oleogels, liposomes, microcapsules and micelles. The opportunities, fabrication and characterization of these delivery systems loaded with DHA/EPA are highlighted. Besides, food sources of DHA/EPA, their benefits to the human body and a series of challenges for effective utilization of DHA/EPA are discussed. Promising future research trends of food-grade systems for delivery of DHA/EPA are also presented. Conducting in vivo experiments, applying DHA/EPA-loaded delivery systems into real food, improving the applicability of such delivery systems in industrial production, co-encapsulating DHA/EPA with other substances, seeking measures to improve the performance of existing delivery systems and developing novel food-grade delivery systems inspired by other fields are various future considerations.

Suppression of palmitic acid-induced hepatic oxidative injury by neohesperidin-loaded pectin-chitosan decorated nanoliposomes

The biological activity of neohesperidin (NH, a flavanone glycoside) is limited due to instability in the physiological environment. Thus, the current study aimed to explore the protective effect of NH-loaded pectin-chitosan decorated liposomes (P-CH-NH-NL) against palmitic acid (PA)-induced hepatic oxidative injury in L02 cells. The particles were characterized using DLS, TEM, HPLC, DSC, and cellular uptake study. Then, the protective effect of NH-loaded liposomal systems (NH-NLs) against PA-induced oxidative injury was evaluated in terms of cell viability study, intracellular ROS, superoxide ions (O₂^-), MMP, and cellular GSH determination. Our results exhibited that NH-NLs significantly lessened the PA-induced hepatic oxidative injury in L02 cells via decreasing ROS and O₂^- generation, reducing MMP collapse, and attenuating GSH reduction, whereas the free NH samples were ineffective. Furthermore, the coated NH-NLs were more effective than that of uncoated nanoliposome. Overall, our study confirmed that P-CH-NH-NL was capable of reducing PA-induced hepatic oxidative injury. Therefore, the pectin-chitosan decorated nanoliposome can be considered as an efficient delivery system for enhancing cellular uptake of lipophilic compound with controlled release and greater biological activity.

Biopolymer-liposome hybrid systems for controlled delivery of bioactive compounds: Recent advances

Conventional liposomes still face many challenges associated with the poor physical and chemical stability, considerable loss of encapsulated cargo, lack of stimulus responsiveness, and rapid elimination from blood circulation. Integration of versatile functional biopolymers has emerged as an attractive strategy to overcome the limitation of usage of liposomes. This review comprehensively summarizes the most recent studies (2015-2020) and their challenges aiming at the exploration of biopolymer-liposome hybrid systems, including surface-modified liposomes, biopolymer-incorporated liposomes, guest-in-cyclodextrin-in-liposome, liposome-in-hydrogel, liposome-in-film, and liposome-in-nanofiber. The physicochemical principles and key technical information underlying the combined strategies for the fabrication of polymeric liposomes, the advantages and limitations of each of the systems, and the stabilization mechanisms are discussed through various case studies. Special emphasis is directed toward the synergistic efficiencies of biopolymers and phospholipid bilayers on encapsulation, protection, and controlled delivery of bioactives (e.g., vitamins, carotenoids, phenolics, peptides, and other health-related compounds) for the biomedical, pharmaceutical, cosmetic, and functional food applications. The major challenges, opportunities, and possible further developments for future studies are also highlighted.