Delivery Vehicles For Curcumin Research Articles

Constructing Dendrobium officinale extracts-coated zein nanoparticles as oral delivery vehicles for curcumin

The aim of this study is to apply aqueous extracts of fresh Dendrobium officinale (DOE) to modify the properties of zein, and increase synergistically the activity of curcumin (Cur). DOE was prepared using a water-extraction method firstly. Then, DOE coated-zein nanoparticles (DLZ NPs) were developed by an antisolvent precipitation method. The results showed that DOE coating improved the dispersity and stability of zein NPs greatly. At a suitable DOE content, spherical DLZ NPs with small particle size (∼200 nm) were established. They exhibited good aqueous stability and redispersibility. Then, Cur was well encapsulated (encapsulation efficiency>98%) in DLZ NPs in an amorphous state. Compared with raw Cur, Cur/DLZ NPs had more than 3.0-fold bioaccessibility, 6.8-fold antioxidant activity and higher antitumor activity, where DOE coating played a well synergistic role. Moreover, DOE coating increased the cellular uptake of zein NPs significantly. These findings suggest that DLZ NPs are promising vehicles for the oral delivery of hydrophobic bioactive substances.

Pectin-coated whey protein isolate/zein self-aggregated nanoparticles as curcumin delivery vehicles: Effects of heating, pH, and adding sequence

In this work, pectin was employed as a coating material to fabricate zein/whey protein isolate (WPI)/pectin complex nanoparticles via a pH-adjusted and heat-induced electrostatic adsorption process for potential oral administration applications of curcumin. Factors such as the order of raw material addition, heating temperature and pH, and zein concentration were comprehensively examined. In addition to electrostatic interactions, Fourier transform infrared and fluorescence spectroscopy indicated that hydrophobic interactions and hydrogen bonds were also involved in the development of complex nanoparticles. The complex nanoparticles obtained not only improved the antioxidant activity of curcumin in aqueous phase, but also contributed to its controlled release under gastrointestinal conditions. Our findings revealed that the heating pH and adding sequence of raw materials had a notable impact on the properties of complex nanoparticles, and that pectin coating had an exceptional stabilizing effect on complex nanoparticles under gastrointestinal circumstances. This study provides novel insights and perspectives for the preparation of polysaccharide-protein complex nanoparticles, signifying the potential use of zein/WPI/pectin complex nanoparticles as delivery vehicles in the functional food and pharmaceutical industries.

PH-dependent release properties of curcumin encapsulated alginate nanoparticles in skin and artificial sweat

Topical skin application of curcumin is challenging due to the low solubility and poor stability, including fast photodegradation, of this bioactive compound. Therefore, curcumin encapsulated alginate (CU-Al) nanoparticles were prepared by the ionic gelation method followed by freeze drying to determine the efficacy of alginate in facilitating curcumin release. Evaluation of the release of curcumin from the encapsulate in the presence of artificial sweat (pH 4.7) and skin (pH 5.5), about which the literature is meagre, was carried out after particle size characterization. CU-Al nanoparticles were in the nano-range (186.8 nm), assimilated a negative zeta-potential value (-15.4 ± 8.13 mV), and displayed a high encapsulation efficiency (94.55 ± 0.53%). The release of encapsulated curcumin at pH 5.5 (max. 64%) and at pH 4.7 (max. 27%) were significantly different. In pH 5.5 and pH 4.7, the release profiles of encapsulated curcumin fitted best with the Weibull (followed an anomalous transport mechanism) and Gompertz (followed a super case II transport mechanism) models respectively, displaying sigmoidal release patterns. Diffusion and polymer relaxation/swelling based release at pH 5.5 and rapid polymer relaxation/erosion based release at pH 4.7 have governed the encapsulated curcumin release. The results indicated that CU-Al nanoparticles may be utilized to facilitate controlled and prolonged release of curcumin in both skin and artificial sweat, thereby functioning as a promising novel delivery vehicle for curcumin. However, skin deposition or penetration may be required for yielding a satisfactory topical administration of curcumin during sweating.

Enzymatically modified quinoa starch based pickering emulsion as carrier for curcumin: Rheological properties, protection effect and in vitro digestion study

Curcumin, as a lipid-soluble and environment-sensitive (light, heat and oxidants) polyphenol, need to be embedded to develop health care products with stable storage-stability and of higher bioaccessibility. Enzymatically modified quinoa starch (EMQS) based emulsion gel was fabricated and used as the carrier for curcumin. The emulsifying property and mechanism of EMQS, and the micromorphology, stability, rheological properties and in vitro digestion properties of the emulsion gel were studied. The decreased particle size and increased contact angle of QS after enzymatic hydrolysis contributed to the improved emulsifying properties of EMQS. The curcumin-encapsulated EMQS Pickering emulsion gel showed better emulsifying stability, much clearer solid-like behavior, higher gel strength and viscosity than that of Tween 80 emulsion. The retention rates of curcumin in the EMQS Pickering emulsion gel were higher than 85% after subjected to the different treatments. And under 7 h UV and 8-day storage conditions, the protective effect of EMQS-based Pickering emulsion gel on curcumin was even higher than that of tween 80 emulsion system. The lipid digestion extent in EMQS Pickering emulsion gel was higher than that in bulk oil system and lower than that in tween 80 system. Compared with that of bulk oil system (5.37%), the bioaccessibility of curcumin in EMQS Pickering emulsion gel (38.57%) was greatly improved, proving that EMQS Pickering emulsion gel could be used as delivery vehicle for curcumin.

A Water in Oil Gelled Emulsion as a Topical Release Vehicle for Curcumin

AbstractThe objective of this work is to assess the influence of the concentration of polyglycerol polyricinoleate (PGPR) (at 1%, 1.5%, and 2%) on the physical properties of water in oil gelled emulsions (W/O) and evaluates their efficiency as a delivery vehicle for curcumin. Emulsions are characterized by drop size, centrifugal test, texture, and rheology during 28 days of storage. When the surfactant concentration increases, smaller droplet sizes are obtained (<5 µm), the phase separation (tested by centrifugal force) decreases from 6% to 4% with little variation of the time. The mechanical properties of emulsions show a tendency to decrease as time passed and concentration of PGPR increased. The emulsions increased viscosity as the concentration increased, but the addition of curcumin reduce the viscosity of the emulsions. About controlled release profiles, a low concentration of PGPR shows an increase in the affinity between curcumin and the emulsions, following a pseudo‐Fickian release behavior. At higher concentration of PGPR shows a decrease in the affinity between curcumin and the emulsion, displaying a Fickian release behavior. The authors were able to prepare tailor made curcumin water in oil emulsion systems for the topical release of this compound.

Antiproliferative and ROS Regulation Activity of Photoluminescent Curcumin-Derived Nanodots.

Recently, various types of nanomaterials have been employed to design delivery vehicles for curcumin to address the problems of poor bioavailability, low aqueous solubility, and rapid metabolism. The present study focuses on a direct one-pot synthesis of curcumin-derived nanoparticles and exploits their potential therapeutic properties in cancer cells in vitro without additional delivery vehicles. The nanoparticles, named E-Curc-dots, are synthesized using three precursor molecules, ethylenediamine (EDA), curcumin, and citric acid. The structure, composition, and physichemical properties of the nanodots are characterized and identified by employing spectroscopic and microscopic techniques. The as-synthesized E-Curc-dots exhibit bright blue photoluminescence due to the incorporation of nitrogen from the EDA precursor molecule. The characterization studies show a uniform distribution of dots with an average size of 4.6 ± 1.7 nm and, notably, that the dots retain some of the major characteristics of native curcumin with much improved water solubility and bioavailability. The E-Curc-dots show antioxidation activity at low concentrations (<0.08 mg/mL) with low levels of reactive oxygen species (ROS) generation, i.e., 82% of the ROS level in cells without treatment for A549 cells; however, at high concentrations, the nanodots exhibit a pro-oxidant effect on both the cancer cells (A549) and normal cells (EA.hy926) by inducing more ROS generation and dose-dependent cytotoxicity. The E-Curc-dots demonstrate higher cytotoxicity toward cancer cells compared to native curcumin at a lower concentration. The results indicate the efficacy of E-Curc-dots as an antiproliferative and ROS regulator with the ability of cellular bioimaging.

Effect of sodium chloride on formation and structure of whey protein isolate/hyaluronic acid complex and its ability to loading curcumin

Effects of ionic strength (0–150 mM NaCl) on formation and properties of whey protein isolate (WPI) and hyaluronic acid (HA) complexes (WPI/HA = 4:1, total concentration of 0.1%, w/w) were investigated. Subsequently, coacervates with corresponding NaCl were applied as delivery vehicle for curcumin. Turbidity analysis showed that NaCl enhanced WPI and HA complexation at 5–40 mM. Adding NaCl (0–150 mM) shifted pHφ1 and pHφ2 towards lower and higher pH values, respectively. Zeta potential measurement showed that surface charge of complexes decreased with increasing NaCl concentration. Circular dichroism and fluorescence spectra indicated that α-helix content and fluorescence intensity of WPI involved in complexation changed with increase of varied NaCl concentration. Isothermal Titration Calorimetry data and Confocal Laser Microscope analysis showed that screening effect of NaCl hindered electrostatic interaction, whereas hydrophobic force may promote complexation at NaCl concentration of 0–30 mM. Fluorescence quenching data revealed that presence of salt at low (5–40 mM) and high (50–150 mM) levels increased and decreased binding ability of WPI/HA with curcumin, respectively. Presence of salt at 5–40 mM improved particle size, encapsulation efficiency and loading capacity compared with control. Data demonstrated that critical NaCl concentration was around 40 mM and this finding could facilitate applications of WPI/HA complex as delivery vehicle of bioactive substances.

Construction of carboxymethyl konjac glucomannan/chitosan complex nanogels as potential delivery vehicles for curcumin

Construction of nanoscale delivery systems from natural food biopolymer complexes have attracted increasing interests in the fields of food industries. In this study, novel carboxymethyl konjac glucomannan/ chitosan (CMKGM/CS) nanogels with and without 1-ethyl-3-(3-dimethylaminopropyl) /N-hydroxysuccinimide) (EDC/NHS)-initiated crosslinking were prepared. The physicochemical and structural properties of the CMKGM/CS nanogels and their potential to be a delivery vehicle for curcumin were investigated. Compared to original uncrosslinked nanogels, crosslinking did not alter particle size and morphology but decreased zeta potential of nanogels. Fourier transform infrared spectrum confirmed that the amide linkage was formed between CMKGM and CS, which obviously enhanced the stability of crosslinked nanogels under gastrointestinal conditions. Furthermore, the crosslinked nanogels not only had higher encapsulation efficiency of curcumin but also better sustained release behavior under simulated gastrointestinal conditions. These findings suggested that the crosslinked CMKGM/CS nanogels might be a promising delivery system for nutrients.

Production of self-assembling acylated ovalbumin nanogels as stable delivery vehicles for curcumin

In this study, we evaluated potential usage of acylated ovalbumin (AOVA) nanogels fabricated via acylation modification and heat-induced self-assembly process as novel delivery systems for curcumin. Compared to native ovalbumin (NOVA) nanogels without chemical acylation, the obtained AOVA nanogels have shown smaller average hydrodynamic diameter (155.73 nm), relatively uniform size distribution (polydispersity index around 0.28), enhanced negative surface charge (-24.3 mV), and an improved stability under the conditions of high ionic strength, different pH and storage time. Moreover, AOVA nanogels exhibited a remarkable conformational change in secondary and tertiary structures, improved surface hydrophobicity, and increased free sulfhydryl content compared with NOVA nanogels. Moreover, curcumin encapsulated in AOVA nanogels displayed higher encapsulation efficiency (93.64%) and slower sustained release under simulated gastrointestinal conditions as compared with NOVA nanogels. Hence, we have suggested that AOVA nanogels successfully fabricated with improved physicochemical properties as a novel ideal carrier for hydrophobic active compounds.

Comparison of cubosomes and liposomes for the encapsulation and delivery of curcumin.

Inverse bicontinuous cubic phase nanoparticles (cubosomes) have attracted significant attention in recent years, owing to their potential use as delivery vehicles for chemically fragile or poorly soluble drugs and nutraceuticals. Herein we have investigated the use of lipid nanoparticles as a delivery vehicle for curcumin, a compound with demonstrated anti-cancer properties. Curcumin is encapsulated within cubosomes comprised of several different lipid formulations, as well as phospholipid-based liposomes. The entrapment efficiency of curcumin within cubosomes was observed to vary depending on both the nanoparticle architecture and the curcumin concentration. Fluorescence spectroscopy analysis revealed that penetration of curcumin into the hydrophobic region of the bilayer was dependent on lipid composition. Curcumin was typically associated with the polar headgroup region at low concentrations, but transferred to the lipid bilayer region at higher concentrations, particularly in phytantriol cubosomes. Each nanoparticle formulation was characterized using small angle X-ray scattering and dynamic light scattering to assess the structural stability subsequent to curcumin encapsulation. The structure of the cubosomes was generally robust to the addition of curcumin, while the liposomes displayed a large increase in particle size and PDI at higher curcumin concentrations. Finally, the cytotoxicity of each formulation was assessed against murine fibroblast (NIH3T3) and murine melanoma (B16F10) cell lines in order to investigate improvements in curcumin bioavailability following encapsulation in cubosomes, as well as assess potential anti-cancer applications. Increased cytotoxicity of the cubosome-loaded curcumin against the murine melanoma cell-line demonstrates the potential of these nanoparticles as delivery vehicles for curcumin and other poorly water-soluble drugs.

Development, Characterization Optimization, and Assessment of Curcumin-Loaded Bioactive Self-Nanoemulsifying Formulations and Their Inhibitory Effects on Human Breast Cancer MCF-7 Cells

Curcumin (CUR) is an attractive polyphenol for its anti-inflammatory, antibacterial, antioxidant, and anticancer properties. Poor solubility in water and sensitivity against sunlight are the most challenging characteristics in the development of CUR for clinical use. The aim is to develop oral lipid-based bioactive self-nanoemulsifying drug delivery systems (Bio-SNEDDSs) for curcumin as a candidate for cancer therapy. Bio-SNEDDSs containing black seed oil, medium-chain mono- and diglycerides, and surfactants were prepared as CUR delivery vehicles. The morphology, droplet size, physical stability, encapsulation efficiency, risk of precipitation, lipid digestion, antioxidant activity, and antimicrobial activity were evaluated for the representative formulations. Finally, an MTT assay was performed on MCF-7 cells to determine the cytotoxic effect of the different formulations. The results showed lower droplet size (28.53 nm) and higher drug-loading (CUR 20 mg, thymoquinone 1.2 mg) for the representative Bio-SNEDDS (black seed oil/Imwitor 988/KolliphorEL (35/15/50) % w/w), along with a transparent appearance upon aqueous dilution. The dynamic dispersion and in-vitro lipolysis data proved that the Bio-SNEDDS was able to keep the CUR in a solubilized form in the gastrointestinal tract. From the antioxidant and antimicrobial studies, it was suggested that the Bio-SNEDDS had the highest activity for disease control. The MTT assay showed that the representative Bio-SNEDDS treatment led to a reduction of cell viability of MCF-7 cells compared to pure CUR and conventional SNEDDSs. A Bio-SNEDDS with elevated entrapment efficiency, antioxidant/antimicrobial activities, and an antiproliferative effect could be the best anticancer drug candidate for potential oral delivery.

Core-shell pea protein-carboxymethylated corn fiber gum composite nanoparticles as delivery vehicles for curcumin

Nanocomposites from plant-derived polysaccharides and proteins are green and sustainable materials that can be applied in various food and biomedical fields. In this work, we developed a novel core-shell nanocomposite from carboxymethylated corn fiber gum (CMCFG) and high nutritious pea protein (PP) for curcumin (Cur) delivery. In the preparation, PP-Cur complexes (PP-Cur) were formed at pH 7.0 and then coated by CMCFG via hydrophobic interactions to form PP-Cur-CMCFG complexes. Furthermore, the interactions between CMCFG and PP-Cur in the complexes were enhanced at pH 3.5 by electrostatic interactions. The resulting nanocomposite exhibited an excellent encapsulation performance for Cur with high Cur loading efficiency, good water dispersibility, and high chemical and thermal stability. Besides, the Cur-loaded core-shell nanocomposite also showed higher antioxidant and radical scavenging activities than Cur. Our results provide support for the use of plant-derived delivery systems as a strategy for the delivery of chemically unstable hydrophobic Cur.

Mechanistic Evaluation of Enhanced Curcumin Delivery through Human Skin In Vitro from Optimised Nanoemulsion Formulations Fabricated with Different Penetration Enhancers.

Curcumin is a natural product with chemopreventive and other properties that are potentially useful in treating skin diseases, including psoriasis and melanoma. However, because of the excellent barrier function of the stratum corneum and the relatively high lipophilicity of curcumin (log P 3.6), skin delivery of curcumin is challenging. We used the principles of a Quality by Design (QbD) approach to develop nanoemulsion formulations containing biocompatible components, including Labrasol and Lecithin as surfactants and Transcutol and ethanol as cosurfactants, to enhance the skin delivery of curcumin. The nanoemulsions were characterised by cryo-SEM, Zeta potential, droplet size, pH, electrical conductivity (EC) and viscosity (η). Physicochemical long-term stability (6 months) was also investigated. The mean droplet sizes as determined by dynamic light scattering (DLS) were in the lower submicron range (20–50 nm) and the average Zeta potential values were low (range: −0.12 to −2.98 mV). Newtonian flow was suggested for the nanoemulsions investigated, with dynamic viscosity of the nanoemulsion formulations ranging from 5.8 to 31 cP. The droplet size of curcumin loaded formulations remained largely constant over a 6-month storage period. The inclusion of terpenes to further enhance skin permeation was also examined. All nanoemulsions significantly enhanced the permeation of curcumin through heat-separated human epidermal membranes, with the greatest effect being a 28-fold increase in maximum flux (Jmax) achieved with a limonene-based nanoemulsion, compared to a 60% ethanol in water control vehicle. The increases in curcumin flux were associated with increased skin diffusivity. In summary, we demonstrated the effectiveness of nanoemulsions for the skin delivery of the lipophilic active compound curcumin, and elucidated the mechanism of permeation enhancement. These formulations show promise as delivery vehicles for curcumin to target psoriasis and skin cancer, and more broadly for other skin delivery applications.

Development of high internal phase Pickering emulsions stabilised by ovotransferrin–gum arabic particles as curcumin delivery vehicles

SummaryThis study explored feasibility of preparing high internal phase Pickering emulsions (HIPEs) as curcumin delivery vehicles. Particles assembled from ovotransferrin (OVT) and gum arabic (GA) could stabilise HIPEs successfully, and OVT–GA particle‐stabilised HIPEs with extremely high oil fraction of 0.90 were stable. Droplet size and rheological properties of OVT–GA particle‐stabilised HIPEs were dependent on both particle concentration and oil fraction. Either increasing particle concentration or decreasing oil fraction resulted in a decrease of droplet size. Increase in storage modulus and viscosity of HIPEs could be achieved by increasing particle concentration or oil fraction. Food structures with controlled shape could be constructed by OVT–GA particle‐stabilised HIPEs. When compared with bulk MCT oil, OVT–GA particle‐stabilised HIPEs improved both extent of lipolysis and curcumin bioaccessibility significantly. These findings provided novel insight into potential application of HIPEs with extremely high oil fractions in nutraceutical delivery systems.

Fabrication of Curcumin-loaded Gliadin Electrospun Nanofibrous Structures and Bioactive Properties

In this work, the feasibility and potential of food-grade gliadin nanofiber as a delivery vehicle for curcumin were investigated. By optimizing the electrospinning parameters, homogeneous and fine gliadin nanofibers containing different amounts of curcumin were fabricated. It was observed that gliadin micro-nanoparticles were gradually transformed to gliadin nanofibers and thicker nanofibers were obtained with the increment of the gliadin concentration. The electrospun nanofibers were characterized in terms of morphological, molecular, thermal and crystallographic properties. Nanofibers were nearly uniform with smooth surface characteristics and their average diameter ranged between 258 to 375 nm. Encapsulation efficiency of gliadin nanofibers increased with the increment of curcumin loading, which was also confirmed by X-ray diffraction patterns revealing that the most part of curcumin could be encapsulated in gliadin nanofibers. In vitro assessments of nanofibers indicated that the curcumin-loaded gliadin nanofibers showed a controlled release of curcumin and protected its free radical scavenging ability. In addition, these nanofibers showed important levels of antibacterial activities against Staphylococcus aureus and Escherichia coli. Furthermore, the encapsulation of curcumin within nanofibers conspicuously enhanced the antioxidant and antibacterial activities of curcumin within these nanofibers. The results suggested that the gliadin nanofiber could be an available carrier for the delivery of curcumin and has the potential for applications in the food industry and other bioactive delivery systems.

Heteroprotein complex formation of ovotransferrin and lysozyme: Fabrication of food-grade particles to stabilize Pickering emulsions

The present work aimed to fabricate food-grade Pickering emulsions stabilized by heteroprotein complexes formed by ovotransferrin (OVT) and lysozyme (LYS) as lipid-based nutraceutical delivery vehicles. The heteroprotein complexation, as confirmed by turbidity titrations, was proved to be an effective means to prepare food-grade particles. Multiple parameters such as particle size, zeta potential and dispersion stability were characterized in screening for proper OVT–LYS particles as Pickering stabilizers. OVT–LYS particles with OVT/LYS ratio of 8:1 at pH 9.3 met all requirements of eligible Pickering stabilizers such as intermediate wettability. Titrations in the presence of sodium chloride demonstrated that primary driving force of OVT–LYS particle formation was electrostatic attraction. Afterwards, food-grade Pickering emulsions were fabricated using OVT–LYS particles. Visual observation indicated that Pickering emulsions stabilized by OVT–LYS particles at various particle concentrations and oil fractions were stable during one-month storage at room temperature, and OVT–LYS particles could stabilize high internal phase Pickering emulsions at oil fraction of 0.75. Rheological measurements revealed that viscosity and gel-like structures of Pickering emulsions were dependent on particle concentration and oil fraction. When compared with the extent of lipolysis (32.1%) in bulk oil, the extent of lipolysis (71.5%) in OVT–LYS particle-stabilized Pickering emulsion was increased by 39.4%. Curcumin bioaccessibility was increased from 16.1% to 38.3% after encapsulation of curcumin into OVT–LYS particle-stabilized Pickering emulsion. Such improved bioaccessibility demonstrated that OVT–LYS particle-stabilized Pickering emulsion was an effective delivery vehicle for curcumin.

Fabrication of chitosan hydrochloride and carboxymethyl starch complex nanogels as potential delivery vehicles for curcumin

The purpose of this research was to prepare nanogels by covalent cross-linking carboxymethyl starch (CMS) and chitosan hydrochloride (CHC) as novel delivery systems for curcumin. The spherical structure of CHC-CMS nanogels was verified by transmission electron microscopy. Fourier transform infrared spectroscopy confirmed that the amide linkage was formed between CHC and CMS. X-ray diffraction data exhibited that the crystalline structure of CHC was destroyed after covalent cross-linking with CMS, which further confirmed that the CHC-CMS nanogels were formed. Furthermore, the nanogels behaved as viscoelastic solids over the entire frequency range. Meanwhile, the nanogels showed excellent pH-sensitivity and high encapsulation efficiency of curcumin (89.49%–94.01%). Compared to free curcumin, curcumin encapsulated in nanogels displayed sustained release profile in simulated gastrointestinal conditions. These results suggested that the nanogels had been successfully fabricated and could be used as ideal carriers for curcumin and other bioactive compounds in functional foods.

Pickering emulsion stabilized by protein nanogel particles for delivery of curcumin: Effects of pH and ionic strength on curcumin retention

• Pickering emulsion was created using protein nanogel particles (WPN) of ˜80 nm size. • Encapsulation of curcumin (CUR) did not affect droplet size of Pickering emulsions. • Binding constant between CUR and interfacial WPN was higher at pH 3.0 than pH 7.0. • Binding of CUR with interfacial WPN at pH 7.0 was influenced by presence of ions. • Electrostatic and hydrophobic interactions of CUR with WPN impacted retention. This study aimed to design whey protein nanogel particles (WPN)-stabilized Pickering emulsion as a delivery vehicle for curcumin (CUR). Firstly, the effectiveness of WPN to stabilize medium chain triglyceride (MCT) oil was assessed using droplet sizing, microscopy across scales, surface coverage calculations and interfacial viscosity measurements. Then, the ability of this delivery vehicle to encapsulate CUR and the effects of pH and ionic strengths on the retention of CUR were investigated in an in vitro release model at 37 ○ C. Results demonstrate that 1.0 wt% WPN was sufficient to create a monolayer of particles at the droplet surface resulting in ultra-stable droplets that were resistant to coalescence over a year. Addition of 500 μg/ mL of CUR did not result in any change in the droplet size of the Pickering emulsion droplets. The CUR was fully retained within the Pickering emulsions, which might be attributed to the nanometric size of the gaps (≅30 nm) at the interface that did not allow CUR to diffuse out into the release media. The partitioning of CUR to the dispersed phase was influenced by pH of the media. Increased binding affinities between CUR and WPN at the interface (binding affinity constant, K a = 1 × 10 4 M −1 ) existed at pH 3.0 as compared to that at pH 7.0 (K a = 6.67 × 10 1 M −1 ) owing to the electrostatic interactions between CUR and interfacial WPN in the former. Such binding affinities between CUR and interfacial WPN at pH 7.0 was further influenced by presence of ions.

Development of hollow kafirin-based nanoparticles fabricated through layer-by-layer assembly as delivery vehicles for curcumin

In this study, curcumin-loaded kafirin solid and hollow nanoparticles were fabricated through electrostatic layer-by-layer (LbL) deposition of Dextran sulfate/Chitosan components using sodium carbonate as a sacrificing template for the hollow nanoparticles and their structural properties as well as their encapsulation and release properties were analyzed and compared. Hollow LbL kafirin nanoparticles had smaller diameters (around 60 nm) compared with LbL solid nanoparticles. Loading with curcumin had little effect on the particle size and zeta potential of both LbL hollow or LbL solid nanoparticles. TEM images clearly show the cavity inside hollow nanoparticles with light inner shade for the hollow part and dark shade for the shell. LbL hollow nanoparticles showed higher encapsulation efficiency for curcumin than LbL solid nanoparticles. Improved dissolution profiles in gastrointestinal tract was observed for curcumin after loading into hollow and solid LbL nanoparticles when compared with native curcumin; while the hollow structure of LbL nanoparticles displayed less release of curcumin compared to solid nanoparticles. This simultaneous fabrication of two types of LbL nanoparticles (solid and hollow) and comparison of their encapsulation and release properties has never been done before. This work is of practical importance for the selection and utilization of bio based kafirin nanoparticles as delivery vehicles for bioactive compounds.

Development and optimization of self-nanoemulsifying drug delivery systems (SNEDDS) for curcumin transdermal delivery: an anti-inflammatory exposure

The purpose of this work is to develop novel lipid-based self-nanoemulsifying drug delivery systems (SNEDDS) as carriers for transdermal delivery of curcumin. SNEDDS containing black seed oil, medium chain mono- and diglycerides and surfactants, were prepared as curcumin delivery vehicles. Their formation spontaneity, morphology, droplet size, and drug loading were evaluated. Gel preparation containing two of the SNEDDS formulations were used in the carrageenan induced paw edema to evaluate the anti-inflammatory effect. Results showed droplet size as low as 71 nm. The highest drug loading was observed with SNEDDS-F6 of ∼45 mg/g. In in-vivo investigation, SNEDDS-F6 exhibited significant anti-inflammatory activities in terms of 80% reduction in paw edema when compared with positive control. The prepared SNEDDS with the elevated entrapment efficiency, good transdermal penetration ability could be a suitable candidate for effective transdermal curcumin skin delivery.