Stability of trianionic curcumin enhanced by gemini alkyl O -Glucosides and alkyl trimethyl ammonium halides mixed micelles

Cholesterol vs Ergosterol: Influence on the Dynamic and Structural Properties of the Cobalt-Based Metallosomal Bilayer Membrane

Sterol derivatives are a crucial part of liposomes, as their concentration and nature can induce significant alternations in their characteristic features. For natural liposomal-based (phospholipid-based) studies, the bulk literature is already present depicting the role of the concentration or nature of different sterol derivatives in modulation of membrane properties. However, the studies aiming at evaluating the effect of sterol derivatives on synthetic liposomal assemblies are limited to cholesterol (Chl), and a comparative effect with other sterol derivatives, such as ergosterol (Erg), has never been studied. To fill this research gap, through this work, we intend to provide insights into the concentration-dependent effect of two sterol derivatives (Chl and Erg) on a synthetic liposomal assembly (i.e., metallosomes) prepared via thin film hydration route using a double-tailed metallosurfactant fabricated by modifying cetylpyridinium chloride with cobalt (Co) (i.e., Co:CPC II). The morphological evaluations with cryogenic-transmission electron microscopy (cryo-TEM), atomic force microscopy (AFM), and field emission-scanning electron microscopy (FE-SEM) indicated that metallosomes retained their spherical morphology irrespective of the nature and concentration of sterol derivatives. However, the size, ζ-potential, and lamellar width values were significantly modified with the incorporation of sterol derivatives in a concentration-dependent manner. In-depth studies affirmed that the extent of modulation of the bilayer in terms of hydrophobicity, fluidity, and rigidity was more severe with Chl than Erg. Such differences in the membrane properties lead to their contrasting behavior in the delivery of the broad-spectrum active compound "curcumin". From entrapment to in vitro behavior, the metallosomes demonstrated dissimilar behavior as even though Erg-modified metallosomes (at higher concentrations of Erg) exhibited low entrapment efficiency, they still could easily release >80% of the entrapped drug. In vitro studies conducted with Staphylococcus aureus bacterial cultures further revealed an interesting pattern of activity as the incorporation of Chl reduced the toxicity of the self-assembly, whereas their Erg-modified counterparts yielded slightly augmented toxicity toward these bacterial cells. Furthermore, Chl- and Erg-modified assemblies also exhibited contrasting behavior in their interaction studies with bacterial DNA.

Dapsone-Loaded Mixed Micellar Gel for Treatment OF Acne Vulgaris

Mixed polymeric micelles are potential nanocarriers for topical drug delivery. Dapsone (DAP) is an antibacterial used as anti-acne agent, but challenged by low water solubility and poor skin permeability. In the present study, DAP-loaded mixed micellar gel was developed comprising Pluronics F-68 and F-127. Micelles were prepared by solvent evaporation method and particle size, ex vivo permeation, drug loading, and entrapment efficiency were determined. Central Composite Design was used to optimize formulation. Independent variables were concentration of Pluronics at three levels while micelle size and drug loading capacities were dependent variables. Droplet size ranged from 400 to 500 nm. Transmission electron microscopy revealed spherical morphology of micelles. Optimized micelles were incorporated into gel base using HPMC K100M, Sodium CMC, and Carbopol 980 as gelling agents. Gels were evaluated for pH, drug content, spreadability, rheology, syneresis, ex vivo permeation, and subacute dermal toxicity. Compared with solubility of free DAP (0.24+0.056 µg/ml), solubility in mixed micelles was 18.42±3.4 µg/ml in water at room temperature. Order of spreadability of gels was Na CMC < HPMC < Carbopol 980. Carbopol gels displayed thixotropy with index of 3.17. Syneresis for all gels from day 0 to day 30 was found to be in range of 4.2 to 15.6% w/w. Subacute dermal toxicity studies showed no signs of erythema and edema on rat skin until 21 days. These results suggest that mixed micelles can significantly increase solubility and permeability and sustain release of DAP and are suitable carriers for topical DAP delivery in anti-acne therapies.

Mechanism of the Micellar Solubilization of Curcumin by Mixed Surfactants of SDS and Brij35 via NMR Spectroscopy

The micellar solubilization mechanism of curcumin by mixed surfactants of SDS and Brij35 was investigated at the molecular scale by NMR spectroscopy. Through the investigation of the micelle formation process, types and structures of mixed micelles and solubilization sites, the intrinsic factors influencing the solubilization capacity were revealed. For systems with α_SDS = 0.5 and 0.2, the obtained molar solubilization ratios (MSRs) are consistent with the MSR_ideal values. However, for α_SDS = 0.8, the solubilization capacity of curcumin is weakened compared to the MSR_ideal. Furthermore, only one single mixed SDS/Brij35 micelles are formed for α_SDS = 0.5 and 0.2. However, for α_SDS = 0.8, there are separate SDS-rich and Brij35-rich mixed micelles formed. In addition, NOESY spectra show that the interaction patterns of SDS and Brij35 in mixed micelles are similar for three systems, as are the solubilization sites of curcumin. Therefore, for α_SDS = 0.5 and 0.2 with single mixed micelles formed, the solubility of curcumin depends only on the mixed micelle composition, which is almost equal to the surfactant molar ratio. Although curcumin is solubilized in both separate micelles at α_SDS = 0.8, a less stable micelle structure may be responsible for the low solubility. This study provides new insights into the investigation and application of mixed micelle solubilization.

Self-assembled nano-micelles of lactoferrin peptides: Structure, physicochemical properties, and application for encapsulating and delivering curcumin

Food-derived protein hydrolysate exhibits good bioactivity, compatibility, and low toxicity, etc. However, the information on protein hydrolysate-based micelles and their application as carriers for hydrophobic bioactive compounds is limited. In this study, an enzymatic partially hydrolyzed lactoferrin hydrolysate nano-micelle with the size within 50 nm was constructed, and its formation mechanism and delivery characteristics for curcumin (Cur) were studied. The results demonstrated that Cur was loaded into the micelles through hydrophobic interaction, and the encapsulation rate of Cur by nano-micelles was (93.44 ± 0.01)%. In addition, the nano-micelle system demonstrated excellent thermal stability, dilution stability, and storage stability. The in vitro simulated digestion proved that self-assembled nano-micelles could improve the transformation rate and bioaccessibility of Cur. This study revealed that lactoferrin hydrolysate self-assembled nano-micelle is a promising delivery system for hydrophobic bioactive compounds.

Construction and evaluation of ovalbumin-pullulan nanogels as a potential delivery carrier for curcumin

Preparation of protein/polysaccharide nanocomplexes for delivering environment-sensitive bioactive compounds is significant in the fields of functional foods and pharmaceuticals. In this work, ovalbumin-pullulan (OVA-Pul) nanogels were fabricated through Maillard reaction combined with heat treatment. The results of SDS-PAGE, circular dichroism and conjugation yield (84.96%) confirmed the covalent crosslinking of ovalbumin to pullulan. Dynamic light scattering measurements indicated that nanogels and curcumin-loaded nanogels exhibited small particle diameter at around 190 nm and 160 nm, and excellent polydispersity index at 0.227 and 0.146, respectively. OVA-Pul nanogels showed good encapsulation efficiency (88.38%) and loading capacity (8.78%) for curcumin. Transmission electron microscope observations and in vitro gastrointestinal digestion suggested that OVA-Pul nanogels facilitated the controlled release of curcumin and the spherical structure of curcumin-loaded nanogels was damaged during digestion. Notably, both nanogels and curcumin-loaded nanogels showed desirable storage stability during 30 d. Hence, OVA-Pul nanogels have the potential for effectively delivering nutrients and drugs.

Characterization and Dissolution Study of Micellar Curcumin-Spray Dried Powder for Oral Delivery

Introduction

Curcumin faces a major challenge in clinical use due to its poor aqueous solubility, which affects its bioavailability over oral use. The present study was carried out to overcome this problem.

Methods

An amorphous micellar curcumin-spray dried powder (MC-SDP) with self-assembled casein was prepared by the addition of sucrose as a protectant. The dry powder of curcumin-loaded micelles was obtained by a spray-drying technique in the presence of sucrose as a protectant. The MC-SDP in the form of dry powder was further developed into tablets to investigate the dissolution profile. The physical properties of preformed powder were characterized by differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Quantitative analysis in the form of solutions was analyzed by high-performance liquid chromatography (HPLC).

Results

The physical properties demonstrated that MC-SDP varies from dented to smoother surfaces as a function of sucrose. Furthermore, melting transitions of curcumin in the form of MC-SDP were broadened in all sample mixtures, as observed in the DTA thermogram. The XRD spectra showed that the sharp and very intense peaks of single curcumin crystalline structure no longer existed in all MC-SDP forms, indicating that the mixtures were amorphous. Moreover, a further dissolution study of MC-SDP showed a significant increase of drug dissolved with the presence of sucrose, where >80% of curcumin from MC-SDP was dissolved within 30 min.

Conclusion

The study demonstrated the manufacture of micellar spray-dried powder that would contribute to the development of oral delivery of curcumin.

Development of Nanocomplexes for Curcumin Vehiculization Using Ovalbumin and Sodium Alginate as Building Blocks: Improved Stability, Bioaccessibility, and Antioxidant Activity

Type I (Complex I) and type II nanocomplexes (Complex II) were created in this work for curcumin (Cur) delivery using ovalbumin (OVA, 1.0% w/w) and sodium alginate (ALG, 0.5% w/w) as building blocks. OVA was heated at 90 °C for 5 min at pH 7.0 and then coated with ALG at pH 4.2 to produce Complex I; OVA-ALG electrostatic complex was created at pH 4.0, which was treated at 90 °C for 5 min thereafter yielding Complex II. Complex I presented an irregular elliptical shape with a diameter of ∼250 nm, whereas Complex II adopted a defined spherical structure of a smaller size (∼200 nm). Complex II did not dissociate at the pH range of 5-7, which was different from Complex I. Cur was loaded into the nonpolar matrix of nanocomplexes through hydrogen bonding and hydrophobic interactions, and Complex II displayed a higher loading capacity than Complex I. Nanocomplexes were resistant to pepsinolysis during simulated gastrointestinal digestion, which enhanced the stability and controlled release of loaded Cur, thereby improving Cur bioaccessibility from ∼20% (free form) to ∼60%. Additionally, nanocomplexes contributed to the cellular antioxidant activity (CAA) of Cur by promoting its cellular uptake. The CAA of Cur was also better preserved in nanocomplexes especially in Complex II after digestion owing to the increased stability and bioaccessibility. Results from this work highlighted the effect of nanocomplex encapsulation on the performance of Cur and revealed the critical role of preparation method in the physicochemical attributes of nanocomplexes.