Preparation of lipid nanoparticles with high loading capacity and exceptional gastrointestinal stability for potential oral delivery applications

Effects of solid lipid ratio in curcumin loaded emulsions on its gastrointestinal fate: Colloidal stability and mucus absorption efficiency

Emulsions offer a promising approach for enhancing the bioavailability of lipophilic active compounds when administered orally. Nonetheless, the impact of lipid matrix composition on the efficacy of penetration and bioavailability remains uncertain. This research investigated the effects of solid lipid ratio in emulsions on colloidal stability, mucus permeability, and bioavailability in vivo. To assess colloidal stability in the gastrointestinal tract (GIT), Turbiscan was employed. The results indicated that an elevated solid lipid ratio improved intestinal stability through the formation of aggregations that resisted pancreatic absorption, as confirmed by TEM. The absorption in various intestinal sections was tested using the Ussing Chamber model. Notably, emulsion with 0 % solid lipid (G0M10) exhibited the highest cumulative permeation across the duodenum (221.2 ± 21.19 ng), jejunum (713.1 ± 20.93 ng), and ileum (1056.3 ± 392.06 ng) due to its higher in vitro release rate (>60 %) and smaller particle size. The cumulative permeation decreased with increasing solid lipid ratio. CLSM revealed that emulsions with a solid lipid ratio exceeding 50 % exhibited poor mucus permeability within 15 min due to aggregation during the passage in the GIT. However, over an extended penetration time (30 min), higher permeability was observed, reaching approximately 30 μm. In vitro release studies indicated that a higher solid lipid ratio resulted in a reduced release rate of curcumin (<60 %) compared to G0M10 (66.9 ± 3.58 %). Correlation analysis unveiled a positive link between bioavailability and in vitro release rate, while a negative correlation emerged with the solid lipid ratio. This work underscores the significance of solid lipid ratios in emulsions for optimizing bioavailability through their influence on stability, permeability, and release of lipophilic compounds in the GIT.

Guar gum series affect nanostructured lipid carriers via electrostatic assembly or steric hindrance: Improving their oral delivery for phytosterols

Surface modification of nanostructured lipid carriers (NLCs) can be an effective way to improve their oral delivery for active ingredients. In this study, four type of guar gum series modified NLCs for the delivery of phytosterols (PS) were constructed and the effects of the polysaccharides on their structure and physicochemical properties were studied. DLS and AFM results revealed that positively charged polysaccharides could bind to PS-NLCs through electrostatic attraction and made the complexes finally take positive charges, while negatively charged polysaccharides were more likely to fill in the gaps of NLC systems to achieve a balance between electrostatic repulsion and intermolecular forces. Although all four polysaccharides exhibited good storage stability and controlled release of PS in simulated intestinal digestion, PS-NLCs modified with partially hydrolyzed cationic guar gum (PHCG) at medium or high concentrations exhibited better gastric stability, mucoadhesion, and cellular uptake, which had considerable significance for improving the oral bioavailability of PS. This might be related to the coating structure of PHCG-PS-NLCs confirmed by AFM, FTIR, and Raman characterization. This study provide a reference value for designing suitable PS-NLC complexes without synthetic surfactants.

Nanoencapsulated Aquafeeds and Current Uses in Fisheries/Shrimps: A Review

Feeds for aquaculture animals are designed to provide them with the greatest amount of nourishment they need to carry out their regular physiological activities, such as maintaining a potent natural immune system and boosting growth and reproduction. However, the problems that severely hamper this sector's ability to contribute to achieving global food security include disease prevalence, chemical pollution, environmental deterioration, and inadequate feed usage. The regulated release of active aquafeed components; limited water solubility, bioaccessibility, and bioavailability, as well as their potent odour and flavour, limit their utilisation. They are unstable under high temperatures, acidic pH, oxygen, or light. Recent advancements in nano-feed for aquaculture (fish/shrimp) have attract enormous attention due to its excellent nutritional value, defeating susceptibility and perishability. Encapsulation is a multifunctional smart system that could bring benefits of personalized medicine; minimize costs and resources in the preclinical and clinical study in pharmacology. It guarantees the coating of the active ingredient as well as its controlled release and targeted distribution to a particular area of the digestive tract. For instance, using nanotechnology to provide more effective fish/shrimps feed for aquaculture species. The review enables a perspective points on safety and awareness in aquafeeds that have been made by the advancements of nanosystem. Therefore, potential of nano-delivery system in aquafeed industry for aquaculture act as concluding remark on future directions.

Physicochemical and In Vitro Digestion Properties of Curcumin-Loaded Solid Lipid Nanoparticles with Different Solid Lipids and Emulsifiers

Curcumin-loaded solid lipid nanoparticles (Cur-SLN) were prepared using medium- and long chain diacylglycerol (MLCD) or glycerol tripalmitate (TP) as lipid matrix and three kinds of surfactants including Tween 20 (T20), quillaja saponin (SQ) and rhamnolipid (Rha). The MLCD-based SLNs had a smaller size and lower surface charge than TP-SLNs with a Cur encapsulation efficiency of 87.54-95.32% and the Rha-based SLNs exhibited a small size but low stability to pH decreases and ionic strength. Thermal analysis and X-ray diffraction results confirmed that the SLNs with different lipid cores showed varying structures, melting and crystallization profiles. The emulsifiers slightly impacted the crystal polymorphism of MLCD-SLNs but largely influenced that of TP-SLNs. Meanwhile, the polymorphism transition was less significant for MLCD-SLNs, which accounted for the better stabilization of particle size and higher encapsulation efficiency of MLCD-SLNs during storage. In vitro studies showed that emulsifier formulation greatly impacted on the Cur bioavailability, whereby T20-SLNs showed much higher digestibility and bioavailability than that of SQ- and Rha-SLNs possibly due to the difference in the interfacial composition. Mathematical modeling analysis of the membrane release further confirmed that Cur was mainly released from the intestinal phase and T20-SLNs showed a faster release rate compared with other formulations. This work contributes to a better understanding of the performance of MLCD in lipophilic compound-loaded SLNs and has important implications for the rational design of lipid nanocarriers and in instructing their application in functional food products.

Solid lipid nanoparticles cyclodextrin-decorated incorporated into gellan gum-based dry floating in situ delivery systems for controlled release of bioactive compounds of safflower (Carthamus tinctorius. L): A proof of concept study in biorelevant media

Safflower (Carthamus tinctorius L.) has been explored as a source of natural antioxidant. However, quercetin 7-O-beta-D-glucopyranoside and luteolin 7-O-beta-D-glucopyranoside, as its bioactive compounds, possessed poor aqueous solubility, limiting its efficacy. Here, we developed solid lipid nanoparticles (SLNs) decorated with hydroxypropyl beta-cyclodextrin (HPβCD) incorporated into dry floating gel in situ systems to control the release of both compounds. Using Geleol® as a lipid matrix, SLNs were <200 nm in size with >80 % of encapsulation efficiency. Importantly, following the decoration using HPβCD, the stability of SLNs in gastric environment was significantly improved. Furthermore, the solubility of both compounds was also enhanced. The incorporation of SLNs into gellan gum-based floating gel in situ provided desired flow and floating properties, with <30 s gelation time. The floating gel in situ system could control the release of bioactive compounds in FaSSGF (Fasted-State Simulated Gastric Fluid). Furthermore, to assess the effect of food intake on release behavior, we found that the formulation could show a sustained release pattern in FeSSGF (Fed-State Simulated Gastric Fluid) for 24 h after being released in FaSGGF for 2 h. This indicated that this combination approach could be a promising oral delivery for bioactive compounds in safflower.

High amount of lecithin facilitates oral delivery of a poorly soluble pyrazoloquinolinone ligand formulated in lipid nanoparticles: Physicochemical, structural and pharmacokinetic performances

Preclinical development of deuterated pyrazoloquinolinone ligands, promising drug candidates for various neuropsychiatric disorders, was hindered by unusually low solubility in water and oils. DK-I-60-3 (7-methoxy-d3-2-(4-methoxy-d3-phenyl)-2,5-dihydro-3Hpyrazolo[4,3-c]quinolin-3-one) is one of such pyrazoloquinolinones, and we recently reported about increased oral bioavailability of its nanocrystal formulation (NC). Lipid nanoparticles (LNP) with a high concentration of lecithin, which enhances loading capacity of the lipid matrix, may give rise to further improvement. After preformulation studies by differential scanning calorimetry and polarized light microscopy, LNP were prepared by the hot high pressure homogenization, and characterized in terms of particle size, morphology, and encapsulation efficacy. The layered structure visible on atomic force micrographs was confirmed by nuclear magnetic resonance. Obtained formulations were desirably stable, with small particle size (<100 nm), and high encapsulation efficacy (>99 %). Lecithin was partially fluid and most probably located in the outer shell of the particle, together with DK-I-60-3. While the hydrophobic part of polysorbate 80 was completely immobilized, its hydrophilic part was free in the aqueous phase. In oral neuropharmacokinetic study in rats, an around 1.5-fold increase of area under the curve with LNP compared to NC was noticed both in brain and plasma. In bioavailability study, F value of LNP (34.7 ± 12.4 %) was 1.4-fold higher than of NC (24.5 ± 7.8 %); however, this difference did not reach statistical significance. Therefore, employment of LNP platform in preclinical formulation of DK-I-60-3 imparted an incremental improvement of its physicochemical as well as pharmacokinetic behavior.

Tailoring Apixaban in Nanostructured Lipid Carrier Enhancing Its Oral Bioavailability and Anticoagulant Activity

Apixaban (Apx), an oral anticoagulant drug, is a direct factor Xa inhibitor for the prophylaxis against venous thromboembolism. Apx has limited oral bioavailability and poor water solubility. The goal of this study was to improve the formulation of an Apx-loaded nanostructured lipid carrier (NLC) to increase its bioavailability and effectiveness. As solid lipid, liquid lipid, hydrophilic, and lipophilic stabilizers, stearic acid, oleic acid, Tween 80, and lecithin were used, respectively. Utilizing Box-Behnken design, the effects of three factors on NLC particle size (Y1), zeta potential (Y2), and entrapment efficiency percent (Y3) were examined and optimized. The optimized formula was prepared, characterized, morphologically studied, and pharmacokinetically and pharmacodynamically assessed. The observed responses of the optimized Apx formula were 315.2 nm, -43.4 mV, and 89.84% for Y1, Y2, and Y3, respectively. Electron microscopy revealed the homogenous spherical shape of the NLC particles. The in vivo pharmacokinetic study conducted in male Wistar rats displayed an increase in AUC and Cmax by 8 and 2.67 folds, respectively, compared to oral Apx suspension. Moreover, the half-life was increased by 1.94 folds, and clearance was diminished by about 8 folds, which makes the NLC formula a promising sustained release system. Interestingly, the pharmacodynamic results displayed the superior effect of the optimized formula over the drug suspension with prolongation in the cuticle bleeding time. Moreover, both prothrombin time and activated partial thromboplastin time are significantly increased. So, incorporating Apx in an NLC formula significantly enhanced its oral bioavailability and pharmacodynamic activity.

Nanocarrier system: An emerging strategy for bioactive peptide delivery

Compared with small-molecule synthetic drugs, bioactive peptides have desirable advantages in efficiency, selectivity, safety, tolerance, and side effects, which are accepted by attracting extensive attention from researchers in food, medicine, and other fields. However, unacceptable barriers, including mucus barrier, digestive enzyme barrier, and epithelial barrier, cause the weakening or the loss of bioavailability and biostability of bioactive peptides. The nanocarrier system for bioactive peptide delivery needs to be further probed. We provide a comprehensive update on the application of versatile delivery systems for embedding bioactive peptides, including liposomes, polymer nanoparticles, polysaccharides, hydrogels, and self-emulsifying delivery systems, and further clarify their structural characterization, advantages, and disadvantages as delivery systems. It aims to provide a reference for the maximum utilization of bioactive peptides. It is expected to be an effective strategy for improving the bioavailability and biostability of bioactive peptides.

Plant-Based Colloidal Delivery Systems for Bioactives

The supplementation of plant-based foods and beverages with bioactive agents may be an important strategy for increasing human healthiness. Numerous kinds of colloidal delivery systems have been developed to encapsulate bioactives with the goal of improving their water dispersibility, chemical stability, and bioavailability. In this review, we focus on colloidal delivery systems assembled entirely from plant-based ingredients, such as lipids, proteins, polysaccharides, phospholipids, and surfactants isolated from botanical sources. In particular, the utilization of these ingredients to create plant-based nanoemulsions, nanoliposomes, nanoparticles, and microgels is covered. The utilization of these delivery systems to encapsulate, protect, and release various kinds of bioactives is highlighted, including oil-soluble vitamins (like vitamin D), ω-3 oils, carotenoids (vitamin A precursors), curcuminoids, and polyphenols. The functionality of these delivery systems can be tailored to specific applications by careful selection of ingredients and processing operations, as this enables the composition, size, shape, internal structure, surface chemistry, and electrical characteristics of the colloidal particles to be controlled. The plant-based delivery systems discussed in this article may be useful for introducing active ingredients into the next generation of plant-based foods, meat, seafood, milk, and egg analogs. Nevertheless, there is still a need to systematically compare the functional performance of different delivery systems for specific applications to establish the most appropriate one. In addition, there is a need to test their efficacy at delivering bioavailable forms of bioactives using in vivo studies.

Microbial production and recovery of hybrid biopolymers from wastes for industrial applications- a review

Agro-industrial wastes to be a global concern since agriculture and industrial processes are growing exponentially with the fast increase of the world population. Biopolymers are complex molecules produced by living organisms, but also found in many wastes or derived from wastes. The main drawbacks for the use of polymers are the high costs of the polymer purification processes from waste and the scale-up in the case of biopolymer production by microorganisms. However, the use of biopolymers at industrial scale for the development of products with high added value, such as food or biomedical products, not only can compensate the primary costs of biopolymer production, but also improve local economies and environmental sustainability. The present review describes some of the most relevant aspects related to the synthesis of hybrid materials and nanocomposites based on biopolymers for the development of products with high-added value.

Improved Bioavailability of Poorly Soluble Drugs through Gastrointestinal Muco-Adhesion of Lipid Nanoparticles

Gastrointestinal absorption remains indispensable in the systemic delivery of most drugs, even though it presents several challenges that, paradoxically, may also provide opportunities that can be exploited to achieve maximal bioavailability. Drug delivery systems made from nanoparticle carriers and especially, lipid carriers, have the potential to traverse gastrointestinal barriers and deploy in the lymphatic pathway, which aptly, is free from first pass via the liver. Several poorly soluble drugs have presented improved systemic bioavailability when couriered in lipid nanoparticle carriers. In this review, we propose an additional frontier to enhancing the bioavailability of poorly soluble drugs when encapsulated in lipid nano-carriers by imparting muco-adhesion to the particles through application of appropriate polymeric coating to the lipid carrier. The combined effect of gastrointestinal muco-adhesion followed by lymphatic absorption is a promising approach to improving systemic bioavailability of poorly soluble drugs following oral administration. Evidence to the potential of this approach is backed-up by recent studies within the review.

Potential therapeutic applications of AKAP disrupting peptides

The 3'-5'-cyclic adenosine monophosphate (cAMP)/PKA pathway represents a major target for pharmacological intervention in multiple disease conditions. Although the last decade saw the concept of highly compartmentalized cAMP/PKA signaling consolidating, current means for the manipulation of this pathway still do not allow to specifically intervene on discrete cAMP/PKA microdomains. Since compartmentalization is crucial for action specificity, identifying new tools that allow local modulation of cAMP/PKA responses is an urgent need. Among key players of cAMP/PKA signaling compartmentalization, a major role is played by A-kinase anchoring proteins (AKAPs) that, by definition, anchor PKA, its substrates and its regulators within multiprotein complexes in well-confined subcellular compartments. Different tools have been conceived to interfere with AKAP-based protein-protein interactions (PPIs), and these primarily include peptides and peptidomimetics that disrupt AKAP-directed multiprotein complexes. While these molecules have been extensively used to understand the molecular mechanisms behind AKAP function in pathophysiological processes, less attention has been devoted to their potential application for therapy. In this review, we will discuss how AKAP-based PPIs can be pharmacologically targeted by synthetic peptides and peptidomimetics.

Optimization of Tilmicosin-Loaded Nanostructured Lipid Carriers Using Orthogonal Design for Overcoming Oral Administration Obstacle

Tilmicosin (TMS) is widely used to treat bacterial infections in veterinary medicine, but the clinical effect is limited by its poor solubility, bitterness, gastric instability, and intestinal efflux transport. Nanostructured lipid carriers (NLCs) are nowadays considered to be a promising vector of therapeutic drugs for oral administration. In this study, an orthogonal experimental design was applied for optimizing TMS-loaded NLCs (TMS-NLCs). The ratios of emulsifier to mixed lipids, stearic acid to oleic acid, drugs to mixed lipids, and cold water to hot emulsion were selected as the independent variables, while the hydrodynamic diameter (HD), drug loading (DL), and entrapment efficiency (EE) were the chosen responses. The optimized TMS-NLCs had a small HD, high DL, and EE of 276.85 ± 2.62 nm, 9.14 ± 0.04%, and 92.92 ± 0.42%, respectively. In addition, a low polydispersity index (0.231 ± 0.001) and high negative zeta potential (-31.10 ± 0.00 mV) indicated the excellent stability, which was further demonstrated by uniformly dispersed spherical nanoparticles under transmission electron microscopy. TMS-NLCs exhibited a slow and sustained release behavior in both simulated gastric juice and intestinal fluid. Furthermore, MDCK-chAbcg2/Abcb1 cell monolayers were successfully established to evaluate their absorption efficiency and potential mechanism. The results of biodirectional transport showed that TMS-NLCs could enhance the cellular uptake and inhibit the efflux function of drug transporters against TMS in MDCK-chAbcg2/Abcb1 cells. Moreover, the data revealed that TMS-NLCs could enter the cells mainly via the caveolae/lipid raft-mediated endocytosis and partially via macropinocytosis. Furthermore, TMS-NLCs showed the same antibacterial activity as free TMS. Taken together, the optimized NLCs were the promising oral delivery carrier for overcoming oral administration obstacle of TMS.

A review on chemical and physical modifications of phytosterols and their influence on bioavailability and safety

Phytosterols have been shown to lower cholesterol levels and to have antioxidant, anti-inflammatory and other biological activities. However, the high melting point and poor solubility limit their bioavailability and practical application. It is advantageous to modify phytosterols chemically and physically. This article reviews and discusses the chemical and physical modifications of phytosterols, as well as their effects on the bioavailability and possible toxicity in vivo. The current research on chemical modifications is mainly focused on esterification to increase the oil solubility and water solubility. For physical modifications (mainly microencapsulation), there are biopolymer-based, surfactant-based and lipid-based nanocarriers. Both chemical and physical modifications of phytosterols can effectively increase the absorption and bioavailability. The safety of modified phytosterols is also an important issue. Phytosterol esters are generally considered to be safe. However, phytosterol oxides, which may be produced during the synthesis of phytosterol esters, have shown toxicity in animal models. The toxicity of nanocarriers also needs further studies.

Advancement of nanoscience in development of conjugated drugs for enhanced disease prevention

Nanoscience and nanotechnology is a recently emerging and rapid developing field of science and has also been explored in the fields of Biotechnology and Medicine. Nanoparticles are being used as tools for diagnostic purposes and as a medium for the delivery of therapeutic agents to the specific targeted sites under controlled conditions. The physicochemical properties of these nanoparticles give them the ability to treat various chronic human diseases by site specific drug delivery and to use in diagnosis, biosensing and bioimaging devices, and implants. According to the type of materials used nanoparticles can be classified as organic (micelles, liposomes, nanogels and dendrimers) and inorganic (including gold nanoparticles (GNPs), super-paramagnetic iron oxide nanomaterials (SPIONs), quantum dots (QDs), and paramagnetic lanthanide ions). Different types of nanoparticle are being used in conjugation with various types of biomoities (such as peptide, lipids, antibodies, nucleotides, plasmids, ligands and polysaccharides) to form nanoparticle-drug conjugates which has enhanced capacity of drug delivery at targeted sites and hence improved disease treatment and diagnosis. In this study, the summary of various types of nanoparticle-drug conjugates that are being used along with their mechanism and applications are included. In addition, the various nanoparticle-drug conjugates which are being used and which are under clinical studies along with their future opportunities and challenges are also discussed in this review.

Biopolymer-Based Nanotechnology Approaches To Deliver Bioactive Compounds for Food Applications: A Perspective on the Past, Present, and Future

Food nanotechnology is an emerging and rapidly evolving field that encompasses an extremely broad range of disciplines and has found various applications in different food sectors. The objective of this perspective is to update the current knowledge on the nanotechnology-based approaches to prepare delivery vehicles for bioactive compounds. Research progress on the development of nanoparticles made from food biopolymers (i.e., protein and polysaccharide) is particularly highlighted. In addition, two types of most recently developed nanoscale delivery systems, i.e., protein-polysaccharide complex and lipid-biopolymer hybrid nanoparticles, are introduced, and their relevant applications are discussed. Finally, suggestions for future research directions on developing safe, effective, and edible nanoscale delivery vehicles for food applications are provided.

Encapsulation of Phloretin in a Ternary Nanocomplex Prepared with Phytoglycogen-Caseinate-Pectin via Electrostatic Interactions and Chemical Cross-Linking

In this study, we chemically modified a phytoglycogen structure to introduce negative surface charge via carboxymethylation (CMPG) and then prepared CMPG-based ternary nanocomplex particles through electrostatic interactions with sodium caseinate (core) and chemical cross-linking with pectin (shell). The chemical cross-linking process by glutaradehyde was systematically optimized under various temperatures and durations. The cross-linked ternary nanocomplex was comprehensively characterized, and our results showed that it had a size of 86 nm with a spherical shape, smooth surface, homogeneous distribution, and negative surface charge. The chemical cross-linking process significantly improved colloidal stability of the nanocomplex under simulated gastrointestinal fluids with digestive enzymes. The as-prepared nanocomplex exhibited exceptional capability to encapsulate phloretin, a natural dihydrochalcone, as a model lipophilic bioactive compound. The nanocomplex not only showed a slow and sustained kinetic release of phloretin under simulated gastrointestinal fluids but also dramatically enhanced its antioxidant activity under an aqueous environment compared to pure phloretin dissolved in ethanol. Findings from this work revealed the promising features of the as-prepared ternary nanocomplex as a potential oral delivery system for lipophilic bioactive compounds.

The influence of oil composition on the transformation, bioaccessibility, and intestinal absorption of curcumin in nanostructured lipid carriers

In this study, the influences of liquid medium-chain triglyceride (MCT) and solid glyceryl tristearate (GTS) contents in the lipid matrix of nanostructured lipid carriers (NLCs) on their delivering capacities with respect to curcumin (Cur) were investigated by using a simulated gastrointestinal tract and Caco-2 monolayer models. The transformation of the encapsulated Cur decreased on increasing the MCT content in the lipid matrix of NLCs because it facilitated their lipolysis and promoted the exposure of Cur to a harsher exterior environment. Cur bioaccessibility was positively correlated with the level of micellized stearic acid resulting from GTS hydrolysis, which might be attributed to the fact that it could afford large hydrophobic domains to accommodate Cur. This value initially increased with an increase in the MCT content, reaching a maximum at 20% (w/w) and decreasing thereafter. The intestinal absorption of micellar Cur ranged from 26.06% to 38.76%, and a majority of the transported molecules were its reductive and conjugative metabolites. Overall, NLC containing 20% MCT in the lipid matrix afforded the highest Cur bioavailability, followed by that containing 10, 0, 40, 60, and 100% MCT. This work provides useful insights into the rational design of NLCs to optimize the bioavailability of the loaded agent.

Nanoliposomes and Tocosomes as Multifunctional Nanocarriers for the Encapsulation of Nutraceutical and Dietary Molecules

Nanoscale lipid bilayers, or nanoliposomes, are generally spherical vesicles formed by the dispersion of phospholipid molecules in a water-based medium by energy input. The other nanoscale object discussed in this entry, i.e., tocosome, is a recently introduced bioactive carrier made mainly from tocopheryl phosphates. Due to their bi-compartmental structure, which consists of lipidic and aqueous compartments, these nanocarriers are capable of carrying hydrophilic and hydrophobic material separately or simultaneously. Nanoliposomes and tocosomes are able to provide protection and release of sensitive food-grade bioactive materials in a sustained manner. They are being utilized for the encapsulation of different types of bioactive materials (such as drugs, vaccines, antimicrobials, antioxidants, minerals and preservatives), for the enrichment and fortification of different food and nutraceutical formulations and manufacturing of functional products. However, a number of issues unique to the nutraceutical and food industry must first be resolved before these applications can completely become a reality. Considering the potentials and promises of these colloidal carrier systems, the present article reviews various aspects of nanoliposomes, in comparison with tocosomes, including the ingredients used in their manufacture, formation mechanisms and issues pertaining to their application in the formulation of health promoting dietary supplements and functional food products.

Synthesis of Tilmicosin Nanostructured Lipid Carriers for Improved Oral Delivery in Broilers: Physiochemical Characterization and Cellular Permeation

This study aimed to develop nanostructured lipid carriers (NLCs) for improved oral absorption of tilmicosin (TMS) in broilers. Thus, palmitic acid, lauric acid, and stearic acid were selected as solid lipids to formulate TMS-pNLCs, TMS-lNLCs, and TMS-sNLCs, respectively. They showed similar physicochemical properties and meanwhile possessed excellent storage and gastrointestinal stability. The TMS interacted with the lipid matrix and was encapsulated efficiently in NLCs in an amorphous structure. NLCs could enhance oral absorption of TMS compared to 10% tilmicosin phosphate solution in broilers, among which the TMS-sNLCs were the most efficient drug delivery carriers, with a relative oral bioavailability of 203.55%. NLCs could inhibit the efflux of P-glycoprotein (P-pg) toward TMS, which may be involved with improved oral absorption. Taken together, these types of solid lipids influenced the enhanced level of NLCs toward oral bioavailability of TMS, and the sNLCs proved to be the most promising oral delivery carriers of TMS.

Carotenoid-loaded nanocarriers: A comprehensive review

Carotenoids retain plenty of health benefits and attracting much attention recently, but they have less resistance to processing stresses, easily oxidized and chemically unstable. Additionally, their application in food and pharmaceuticals are restricted due to some limitations such as poor bioavailability, less solubility and quick release. Nanoencapsulation techniques can be used to protect the carotenoids and to uphold their original characteristics during processing, storage and digestion, improve their physiochemical properties and enhance their health promoting effects. The importance of nanocarriers in foods and pharmaceuticals cannot be denied. This review comprehensively covers recent advances in nanoencapsulation of carotenoids with biopolymeric nanocarriers (polysaccharides and proteins), and lipid-based nanocarriers, their functionalities, aptness and innovative developments in preparation strategies. Furthermore, the present state of the art encapsulation of different carotenoids via biopolymeric and lipid-based nanocarriers have been enclosed and tabulated well. Nanoencapsulation has a vast range of applications for protection of carotenoids. Polysaccharides in combination with different proteins can offer a great avenue to achieve the desired formulation for encapsulation of carotenoids by using different nanoencapsulation strategies. In terms of lipid based nanocarriers, solid lipid nanoparticles and nanostructure lipid carriers are proving as the encouraging candidates for entrapment of carotenoids. Additionally, nanoliposomes and nanoemulsion are also promising and novel-vehicles for the protection of carotenoids against challenging aspects as well as offering an effectual controlled release on the targeted sites. In the future, further studies could be conducted for exploring the application of nanoencapsulated systems in food and gastrointestinal tract (GIT) for industrial applications.

Oxidized Dextran as a Macromolecular Crosslinker Stabilizes the Zein/Caseinate Nanocomplex for the Potential Oral Delivery of Curcumin

In this study, we prepared complex nanoparticles from a combination of two proteins and one polysaccharide for the encapsulation and delivery of lipophilic bioactive compounds. Two proteins, zein and sodium caseinate (NaCas), provided a hydrophobic core for the encapsulation of a lipophilic compound (curcumin), while a polysaccharide dialdehyde, oxidized dextran, served as the coating material and macromolecular crosslinker to create covalent linkage with two proteins for stabilization purposes. The heating time and crosslinker concentration were optimized to achieve the desirable colloidal stability in simulated gastric and intestinal fluids. Our results suggested that heating time played a more important role than the concentration of oxidized dextran. The optimized complex nanoparticles had a particle size of around 150 nm with a PDI < 0.1 and negative surface charge. Morphological observation by transmission electron microscopy revealed a spherical shape and uniform size distribution. Fourier transform infrared and fluorescence spectroscopies evidenced the formation of Schiff base complex, confirming the validity of covalent crosslinking. Furthermore, the complex nanoparticles demonstrated superior encapsulation properties for curcumin, showing an efficiency of >90% at 10% loading. A rather slow kinetic release profile of curcumin from complex nanoparticles was observed under simulated gastrointestinal conditions. The complex nanoparticles prepared from zein, NaCas, and oxidized dextran hold promising potential for the oral delivery of lipophilic bioactive compounds.

Nanostructured lipid carriers for oral delivery of silymarin: Improving its absorption and in vivo efficacy in type 2 diabetes and metabolic syndrome model

Silymarin (SLM) is a mixture of flavonolignans extracted from the fruit of Silybum marianum L. Gaertn. which has been used for decades as a hepatoprotector. Silymarin has recently been proposed to be beneficial in type 2 diabetic patients. Constituents of SLM are poorly water-soluble and low permeable compounds, with consequently limited oral bioavailability. This study aimed to investigate the possibility of delivery of SLM via nanostructured lipid carriers (NLCs) to overcome these issues and for preparation of an oral dosage form. NLCs were prepared through an emulsion/evaporation/solidifying method. Cetyl palmitate:Lauroglycol 90 was selected as the lipid mixture and Brij S20 as surfactant. NLCs were chemically and physically characterized. Encapsulation efficiency was more than 92%. The storage stability of the NLC suspension was also investigated and the freeze-drying process was taken into consideration. After assessing the stability of the formulation in a simulated gastrointestinal environment, the release of SLM was monitored in different pH conditions. In vitro experiments with artificial membranes (PAMPA) and Caco-2 cells revealed that the NLCs enhanced the permeation of SLM. Active processes are involved in the internalization of NLCs, as evidenced by cellular uptake studies. After preliminary toxicological studies, the formulation was studied in vivo in a streptozotocin (STZ)-induced diabetic mouse model in the presence of metabolic syndrome. The formulation was also compared to an NLC containing stearic acid:Capryol 90, to evaluate the effect of the lipid matrix on the in vivo performance of nanocarriers. Finally, hepatic histopathological analyses were also conducted. Both SLM-loaded NLCs exhibited in vivo a significant down-regulation of blood glucose and triglyceride levels better than free SLM, with a liver-protective effect. Furthermore, both formulations showed a significant anti-hyperalgesic effect on STZ-induced neuropathy.

Multifunctional oral delivery systems for enhanced bioavailability of therapeutic peptides/proteins

In last few years, therapeutic peptides/proteins are rapidly growing in drug market considering their higher efficiency and lower toxicity than chemical drugs. However, the administration of therapeutic peptides/proteins is mainly limited in parenteral approach. Oral therapy which was hampered by harsh gastrointestinal environment and poorly penetrating epithelial barriers often results in low bioavailability (less than 1%-2%). Therefore, delivery systems that are rationally designed to overcome these challenges in gastrointestinal tract and ameliorate the oral bioavailability of therapeutic peptides/proteins are seriously promising. In this review, we summarized various multifunctional delivery systems, including lipid-based particles, polysaccharide-based particles, inorganic particles, and synthetic multifunctional particles that achieved effective oral delivery of therapeutic peptides/proteins.

Biological fate of ingested lipid-based nanoparticles: current understanding and future directions

In recent decades, lipid-based nanoparticles (LN) have received considerable attention as nanoscale delivery systems to improve oral bioavailability of poorly absorbed bioactive compounds for health promotion and disease prevention. However, scientific studies on the biological fate of orally administered LN are very limited and the molecular mechanisms by which they are absorbed through the intestinal lumen into the circulation remain unclear. This paper aims to provide an overview of the biological fate of orally administered LN by reviewing recent studies on both cell and animal models. In general, the biological fate of ingested LN in the gastrointestinal tract is primarily determined by their initial physicochemical characteristics (such as the particle size, surface properties, composition and structure), and their absorption mainly occurs within the small intestine. In particular, depending upon the composition, LN can be either digestible or indigestible, with two distinct biological fates for each type of LN. The detailed absorption mechanisms and uptake pathways at molecular, cellular and whole body levels for each type of LN are discussed in detail. Limitations of current research and our vision for future directions to study the biological fate of ingested LN are also provided in this critical review.

Recent advances of polysaccharide-based nanoparticles for oral insulin delivery

Diabetes mellitus is a highly prevalent metabolic and chronic disease affecting millions of people in the world. The most common route of insulin therapy is the subcutaneous injection due to its low bioavailability and enzymatic degradation. The search for effective and high patient compliance insulin delivery systems has been a major challenge over many decades. The polysaccharide-based nanoparticles as delivery vehicles for insulin oral administration have recently attracted substantial interests. The present review highlights the recent advances on the development of nanoparticles prepared from polysaccharides, including chitosan, alginate, dextran and glucan, for oral delivery of insulin, overcoming multiple barriers in gastrointestinal tract. The aims of this review are first to summarize the strategies that have been applied in the past 5 years to fabricate polysaccharide-based nanoparticles for insulin oral delivery, and then to provide in-depth understanding on the mechanisms by which such nanoparticles protect insulin against degradation in the digestive tract and provide sustained release to enhance mucus permeation and transepithelial transport of insulin administered via oral route.

Nanostructured Lipid Carriers as Promising Delivery Systems for Plant Extracts: The Case of Silymarin

Background: Silymarin is the extract from seeds of Silybum marianum L. Gaertn. and it has been used for decades as hepatoprotectant. Recently, it has been proposed to be beneficial in type 2 diabetes patients. However, silymarin is a poorly water soluble drug with limited oral bioavailability. In this study, nanostructured lipid carriers were proposed to enhance its solubility and intestinal absorption. Methods: Nanostructured lipid carriers were made of Stearic acid:Capryol 90 as lipid mixtures and Brij S20 as surfactant. Formulations were physically and chemically characterized. Stability and in vitro release studies were also assessed. In vitro permeability and Caco-2 cellular uptake mechanism were investigated. Results: Obtained results were based on size, homogeneity, ζ-potential and EE%. Nanostructured lipid carriers could be orally administered. No degradation phenomena were observed in simulated gastrointestinal fluids. Storage stability of suspensions and lyophilized products was also tested. Glucose was selected as best cryoprotectant agent. About 60% of silymarin was released in 24 h in phosphate buffered saline. In vitro parallel artificial membrane permeability assay experiments revealed that the nanocarrier enhanced the permeation of Silymarin. Caco-2 study performed with fluorescent nanoparticles revealed the ability of carrier to enhance the permeation of a lipophilic probe. Cellular uptake studies indicated that active process is involved in the internalization of the formulation. Conclusions: The optimized nanostructured lipid carriers showed excellent chemical and physical stability and enhanced the absorption of silymarin.