Physicochemical study of curcumin in oil driven nanoemulsions with surfactants

Development of a new generation of miniemulsion based on cottonseed oil with α-tocopherol and ZnO and evaluation of its adjuvant activity

Background

Emulsions have been widely used as immunological adjuvants. But the use of materials derived from plants such as cottonseed oil, alpha-tocopherol, or minerals such as zinc, as well as their use at the nanometric scale has been little explored. In this study, we develop a new miniemulsion and evaluated its antioxidant and phagocytic capacity, as well as parameters related to immune response stimulation by cytokine expression and antibodies production in a mice model.

Methods

Formulated CN (cottonseed oil miniemulsion) and CNZ (cottonseed oil miniemulsion whit zinc oxide nanoparticles) miniemulsions were characterized by scanning electronic microscopy SEM, DLS and FT-IR. In murine macrophages, splenocytes and thymocytes primary cultures safety and cytotoxicity were determined by MTT. In macrophages the antioxidant and phagocytic capacity was evaluated. In BALB/c mice, the stimulation of the immune system was determined by the expression of cytokines and the production of antibodies.

Results

The CN and CNZ presented stability for 90 days. Immediately after preparation, the CN presented a higher particle size (543.1 nm) than CNZ (320 nm). FT-IR demonstrated the correct nanoparticle synthesis by the absence of sulfate groups. CN and CNZ (1.25 to 10 µL/mL) had no toxic effect on macrophages (p = 0.108), splenocytes (p = 0.413), and thymocytes (p = 0.923). All CN and CNZ doses tested induced nitric oxide and antioxidants production in dose dependent manner when compared with control. CN-ovalbumin and CNZ-ovalbumin treatments in femoral subcutaneous tissue area showed inflammation with higher leukocyte infiltration compared with FCA. The intraperitoneal administration with CN, CNZ, and FCA showed a higher total intraperitoneal cells recruitment (CD14⁺) after 24 h of inoculation than control (p = 0.0001). CN and CNZ increased the phagocyte capacity with respect to untreated macrophages in the Candida albicans-phagocytosis assay. The evaluation of residual CFU indicated that only CN significantly decreased (p = 0.004) this value at 3 h. By other side, only CN increased (p = 0.002) the nitric oxide production. CNZ stimulated a major INFγ secretion compared with FCA at day 7. A major IL-2 secretion was observed at days 7 and 14, stimulated with CN and CNZ. Both miniemulsions did not affect the antibody isotypes production (IgG1, IgG2a, IgG3, IgA and IgM) at days 7, 14, 28, and 42. CN induced a significant IgG production against OVA, but lesser than FCA.

Conclusions

The two new miniemulsions with adjuvant and antioxidant capacity, were capable of generating leukocyte infiltration and increased cytokines and antibodies production.

Challenges of peptide and protein drug delivery by oral route: Current strategies to improve the bioavailability

Advancement in biotechnology provided a notable expansion of peptide and protein therapeutics, used as antigens, vaccines, hormones. It has a prodigious potential to treat a broad spectrum of diseases such as cancer, metabolic disorders, bone disorders, and so forth. Protein and peptide therapeutics are administered parenterally due to their poor bioavailability and stability, restricting their use. Hence, research focuses on the oral delivery of peptides and proteins for the ease of self-administration. In the present review, we first address the main obstacles in the oral delivery system in addition to approaches used to enhance the stability and bioavailability of peptide/protein. We describe the physiochemical parameters of the peptides and proteins influencing bioavailability in the systemic circulation. It encounters, many barriers affecting its stability, such as poor cellular membrane permeability at the GIT site, enzymatic degradation (various proteases), and first-pass hepatic metabolism. Then describe the current approaches to overcome the challenges mentioned above by the use of absorption enhancers or carriers, structural modification, formulation and advance technology.

Associations between sleep and episodic memory updating

Prior research shows that contextual reminders can reactivate hippocampal links to previously consolidated memories, rendering them susceptible to being updated with new information which then is reconsolidated. Studies implicate sleep in the reconsolidation of reactivated memories, but it is unknown what role sleep plays in updating of a previously consolidated trace with new information. We tracked participants' sleep during an episodic reconsolidation paradigm, first with actigraphy (Experiment 1) then with polysomnography (Experiment 2). Our paradigm involved two learning sessions and a retrieval session, each separated by 48 hr. We reminded participants of the first learning experience immediately prior to the second, which led them to update the earlier memory with elements of the later experience. In Experiment 1, less sleep after Session 1 and more sleep after Session 2 are associated with increased updating. In Experiment 2, N2 sleep spindles (SSs) after the reminder and new learning are associated with more updating, but primarily when spindle activity after Session 1 is low. Thus, total sleep time and N2 SSs contribute to sleep-dependent updating of episodic memory. This outcome is consistent with other work connecting SS activity to the integration of novel information into existing knowledge structures, extended here with the study of how variations in sleep over successive nights contribute to this process. We discuss some possible roles of spindles in the decontextualization of hippocampal memory over time. Although much work addresses the role of sleep in the consolidation of new memories, this work uniquely addresses the contribution of sleep to the updating of a previously consolidated trace with new information.

Microbial carbon use efficiency predicted from genome-scale metabolic models

Respiration by soil bacteria and fungi is one of the largest fluxes of carbon (C) from the land surface. Although this flux is a direct product of microbial metabolism, controls over metabolism and their responses to global change are a major uncertainty in the global C cycle. Here, we explore an in silico approach to predict bacterial C-use efficiency (CUE) for over 200 species using genome-specific constraint-based metabolic modeling. We find that potential CUE averages 0.62 ± 0.17 with a range of 0.22 to 0.98 across taxa and phylogenetic structuring at the subphylum levels. Potential CUE is negatively correlated with genome size, while taxa with larger genomes are able to access a wider variety of C substrates. Incorporating the range of CUE values reported here into a next-generation model of soil biogeochemistry suggests that these differences in physiology across microbial taxa can feed back on soil-C cycling.

Philic-phobic chemical dynamics of a 1st tier dendrimer dispersed o/w nanoemulsion

Olive, castor and linseed oil (oil-in-water) nanoemulsions were prepared using Tween-20, sodium dodecyl sulfate, and cetyltrimethylammonium bromide (0.12 w/w%) with 0.02 w/w% cellulose acetate propionate (CAP), 0.02 w/w% cellulose acetate butyrate (CAB), 6.2 w/w% ethyl acetate, 5.5 w/w% ethanol and 7.8 w/w% glycerol as dispersion agents. To study the dispersion effect of trimesoyl 1,3,5-tridimethyl malonate (TTDMM, 1st tier), nanoemulsions were prepared with olive, castor and linseed oil. Their density, viscosity, surface tension and friccohesity measurements at T = (293.15, 303.15, and 315.15) K, hydrodynamic radii, surface excess concentration, surface area per molecule, and antioxidant activities were studied. Dispersion variations of TTDMM on varying surfactant and specific interactions of the hydration spheres and ester moiety of TTDMM with ethyl acetate, ethanol and glycerol linked oil-water-surfactant networks have been established. The variations in physicochemical properties suggest that the oil-TTDMM interaction abilities of the surfactant and co-surfactant moieties in the nanoemulsions cause a hydrophobic segregation. The physicochemical study of both blank and TTDMM loaded nanoemulsions have illustrated the thermodynamic stabilities in terms of hydrophobic-hydrophilic, hydrophilic-hydrophilic, van der Waals and hydrogen bonding interactions.

Co(III) based surfactant complexes and their Dye, BSA and free radical activities

Study reports the preparation of metal/surfactant complexes or Metal Organic Ionic Framework (MOIF) based on ionic interaction of [Co(NH3)6]3+ and Dioctyl sulfosuccinate (AOT)/Sodium dodecyl sulfate (SDS). MOIF is result of strong ionic interaction between cationic and anionic moieties without disturbing their own structures. MOIF of [Co(NH3)6]3+ and SDS was found in solid powdery form while [Co(NH3)6]3+ + AOT produced sticky material. UV/Vis, FTIR, Raman and XRD measurements were used to characterize the MOIFs. The ionic interaction between cationic complex [Co(NH3)6]3+ and anionic sulphur of AOT/SDS was confirmed by comparing spectra with their parental moieties. MOIF containing hydrophilic and hydrophobic groups showed their dye interaction activity studied with methyl orange (MO) and methylene blue (MB) depicting impact of linear and iso-alkyl chain ánd hydrophilic amine groups. MOIF showed their protein binding nature, studied with bovine serum albumin (BSA), analyzed with spectrophotometric titrations revealing that hydrophobicity affects the interaction. In Dye and protein interactions, MOIF of [Co(NH3)6]3+ + AOT showed strong activities than MOIF of [Co(NH3)6]3+ + SDS due to more hydrophobicity associated with MOIF of [Co(NH3)6]3+ + AOT. MOIFs have also shown good scavenging effect tested in vitro against free radical, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and the same, strong interaction for MOIF of [Co(NH3)6]3+ + AOT noticed.

Dispersion enhancing effect of sonochemically functionalized graphene oxide for catalysing antioxidant efficacy of curcumin

The non-hazardous sonochemical approach has been developed for the functionalization of graphene oxide (GrO) with 5-Aminoindazole (5-AIND). The formation of f-(5-AIND) GrO is confirmed with ¹³C solid state NMR, HRXPS, XRD, Raman, TGA, DSC, FTIR etc. The >80% cell viabilities on MCF-7 and Vero cell lines have confirmed the high cytocompatibility of f-(5-AIND) GrO. Additionally, the morphological impact on Vero cell line has evidently confirmed the biocompatibility of f-(5-AIND) GrO. As compared to GrO, the f-(5-AIND) GrO has demonstrated an enhanced antioxidant efficacy of 69.4-72%, evaluated with 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. With a similar objective (0.01-0.05)mL peanut oil based curcumin micro and nanoemulsions have been prepared using ethanol and glycerol as co-solvent and co-surfactant respectively. The prepared emulsions are subsequently characterised with respect to morphological and physicochemical parameters via density, surface tension, viscosity, friccohesity measurement and DLS analysis. Henceforth, with an expectation to achieve higher dispersion, an ethanolic dispersion of f-(5-AIND) GrO has been mixed with curcumin carrying emulsions in 1:1. Notably, the radical scavenging activities (RSA) of the combined formulations are significantly enhanced to an extent of 26.6%.

Study of curcumin antioxidant activities in robust oil–water nanoemulsions

Symbolic representation of increased interactions from oil to CLFs, indicatedviaenhancedρandu.

Understanding the significance of O-doped graphene towards biomedical applications

The cytotoxicity profile, antimicrobial assay and antioxidant efficacy of O-doped graphene have confirmed its significance as an advanced functional biomaterial for biomedical applications. Extensive structural investigations complemented the activity studies.