In vivo biodistribution, anti-inflammatory, and hepatoprotective effects of liver targeting dexamethasone acetate loaded nanostructured lipid carrier system

Nanostructured Lipid Carriers Loaded with Dexamethasone Prevent Inflammatory Responses in Primary Non-Parenchymal Liver Cells

Liver inflammation represents a major clinical problem in a wide range of pathologies. Among the strategies to prevent liver failure, dexamethasone (DXM) has been widely used to suppress inflammatory responses. The use of nanocarriers for encapsulation and sustained release of glucocorticoids to liver cells could provide a solution to prevent severe side effects associated with systemic delivery as the conventional treatment regime. Here we describe a nanostructured lipid carrier developed to efficiently encapsulate and release DXM. This nano-formulation proved to be stable over time, did not interact in vitro with plasma opsonins, and was well tolerated by primary non-parenchymal liver cells (NPCs). Released DXM preserved its pharmacological activity, as evidenced by inducing robust anti-inflammatory responses in NPCs. Taken together, nanostructured lipid carriers may constitute a reliable platform for the delivery of DXM to treat pathologies associated with chronic liver inflammation.

PLGA Based Nanospheres as a Potent Macrophage-Specific Drug Delivery System

Macrophages possess an innate ability to scavenge heterogenous objects from the systemic circulation and to regulate inflammatory diseases in various organs via cytokine production. That makes them attractive targets for nanomedicine-based therapeutic approaches to inflammatory diseases. In the present study, we have prepared several different poly(lactic-co-glycolic acid) (PLGA) polymer nanospheres for macrophage-targeted drug delivery using both nanoprecipitation and emulsification solvent evaporation methods. Two experimental linear PLGA polymers with relatively low molar weight, one experimental branched PLGA with unique star-like molecular architecture, and a commercially available PLGA, were used for nanosphere formulation and compared to their macrophage uptake capacity. The nanosphere formulations labelled with loaded fluorescent dye Rhodamine B were further tested in mouse bone marrow-derived macrophages and in hepatocyte cell lines AML-12, HepG2. We found that nanospheres larger than 100 nm prepared using nanoprecipitation significantly enhanced distribution of fluorescent dye selectively into macrophages. No effects of nanospheres on cellular viability were observed. Additionally, no significant proinflammatory effect after macrophage exposure to nanospheres was detected as assessed by a determination of proinflammatory cytokines Il-1β and Tnfα mRNA. All experimental PLGA nanoformulations surpassed the nanospheres obtained with the commercially available polymer taken as a control in their capacity as macrophage-specific carriers.

Development of Polymeric Micelles of Oleanolic Acid and Evaluation of Their Clinical Efficacy

Oleanolic acid has been used only as a subsidiary agent in cosmetic products. The aim of the study is to show the effect of oleanolic acid as an active ingredient for the alleviation of wrinkles in humans and to develop a polymeric micelle formulation that enables poorly soluble oleanolic acid to be used as a main ingredient in cosmetic products for reducing wrinkles. The solubility of oleanolic acid was evaluated in solubilizers, surfactants, and polymers. The particle sizes and shapes of polymeric micelles containing oleanolic acid were evaluated by electrophoretic light scattering spectrophotometer and scanning electron cryomicroscopy. Encapsulation efficiency and skin permeation were measured by HPLC. Stability of the polymeric micelles stored at 40 °C for 3 months was evaluated by visual observation, particle size measurement, and oleanolic acid content measurement. Polymeric micelles in final product ampoule form were applied around the eyes of 23 female subjects for 8 weeks. Five skin parameters were evaluated by optical profilometry every 4 weeks for 8 weeks. In addition, professionals made visual observations of the skin and a human skin irritation study was conducted. Polymeric micelles of oleanolic acid with a particle size of less than 100 nm were prepared using Capryol 90® and poloxamer. The skin permeation rate of the oleanolic acid in the polymeric micelles was higher than that in the other solutions made of oleanolic acid dispersed in 2 different surfactants. No significant changes in particle size, color, or oleanolic acid content were observed, and the polymeric micelles stored at 40 °C for 3 months did not undergo phase separation. After 8 weeks of application, skin irritation had not developed and all five parameters evaluated by optical profilometry as well as the visual evaluation scores were significantly improved. This study showed that the polymeric micelles of oleanolic acid prepared in this study were stable and effective at alleviating wrinkles in humans as the principal active ingredient. Based on these findings, it is expected that polymeric micelles of oleanolic acid can be widely used in cosmetic applications.

Therapeutic Efficacy of Intratendinous Delivery of Dexamethasone Using Porous Microspheres for Amelioration of Inflammation and Tendon Degeneration on Achilles Tendinitis in Rats

Achilles tendinitis caused by overuse, aging, or gradual wear induces pain, swelling, and stiffness of Achilles tendon and leads to tendon rupture. This study was performed to investigate the suppression of inflammation responses in interleukin-1β- (IL-1β-) stimulated tenocytes in vitro and the suppression of the progression of Achilles tendinitis-induced rat models in vivo using dexamethasone-containing porous microspheres (DEX/PMSs) for a sustained intratendinous DEX delivery. DEX from DEX/PMSs showed the sustained release of DEX. Treatment of IL-1β-stimulated tenocytes with DEX/PMSs suppressed the mRNA levels for COX-2, IL-1β, IL-6, and TNF-α. The intratendinous injection of DEX/PMSs into Achilles tendinitis rats both decreased the mRNA levels for these cytokines and increased mRNA levels for anti-inflammatory cytokines IL-4 and IL-10 in tendon tissues. Furthermore, DEX/PMSs effectively prevented tendon degeneration by enhancing the collagen content and biomechanical properties. Our findings suggest that DEX/PMSs show great potential as a sustained intratendinous delivery system for ameliorating inflammation responses as well as tendon degeneration in Achilles tendinitis.

Application of nanostructured lipid carriers: the prolonged protective effects for sesamol in in vitro and in vivo models of ischemic stroke via activation of PI3K signalling pathway

BACKGROUND

Treatment of the ischemic stroke has remained a major healthcare challenge. The phenolic compound, sesamol, has shown promising antioxidant and neuroprotective effects, however, fast clearance may negatively affect its efficiency. This, prompted us to incorporate sesamol into the nanostructured lipid carriers (S-NLCs) and evaluate its therapeutic potential in in vitro and in vivo models of ischemic stroke.

METHODS

S-NLCs formulations were prepared by high-pressure homogenization followed by physicochemical characterization, evaluation of the bioactivity of the optimal formulation in oxygen-glucose deprivation (OGD) and global cerebral ischemia/reperfusion (I/R) injury and implication of phosphatidylinositol 3-kinase (PI3K) pathway in this regard. Two- or three-way ANOVA, Mann-Whitney U test, and Student's t-test were used for data analysis.

RESULTS

Formation of S-NLCs which exhibited a controlled release profile, was confirmed by scanning electron microscope and differential scanning calorimetry. 1- and 8-h OGD followed by 24 h re-oxygenation significantly reduced PC12 cell viability, increased lactate dehydrogenase activity and the number of condensed nuclei, and induced oxidative stress as revealed by increased malondialdehyde level and decreased glutathione content and superoxide dismutase and catalase activities. Sesamol (80 and 100 μM) reduced the cytotoxicity, oxidative stress, and cellular damage only after 1-h OGD, while, S-NLCs (containing 80 and 100 μM of sesamol) were effective at both time points. Intravenous injections of S-NLCs (20 and 25 mg/kg) into rats markedly attenuated I/R-induced neurobehavioural deficits, cellular damage, and oxidative stress, while, free sesamol failed. Pre-treatment with PI3K inhibitor, LY294002, abolished the protective effects against OGD or I/R.

CONCLUSIONS

S-NLCs improve the pharmacological profile of sesamol and provide longer lasting protective effects for this phenolic phytochemical. This nanoformulation by activating PI3K pathway may serve as a promising candidate for neuroprotection against the cerebral stroke or other neurodegenerative disorders. Sesamol-loaded NLCs, a promising nanoformulation against the ischemic stroke.

Inhibitory effect of a new orally active cedrol-loaded nanostructured lipid carrier on compound 48/80-induced mast cell degranulation and anaphylactic shock in mice

BACKGROUND

Type I hypersensitivity is an allergic reaction characterized by the overactivity of the immune system provoked by normally harmless substances. Glucocorticoids, anti-histamines, or mast cell stabilizers are the choices of treatment for type I hypersensitivity. Even though these drugs have the anti-allergic effect, they can have several side effects in prolong use. Cedrol is the main bioactive compound of Cedrus atlantica with anti-tumor, anti-oxidative, and platelet-activating factor inhibiting properties.

METHODS

In this study, the preparation and anti-anaphylactic effect of cedrol-loaded nanostructured lipid carriers (NLCs) were evaluated. NLCs were prepared using Compritol® 888 ATO and triolein as lipid phase and vitamin E d-α-tocopherylpolyethyleneglycol 1000 succinate, soya lecithin, and sodium deoxycholate as nanoparticle stabilizers.

RESULTS

The average diameter of cedrol-NLCs (CR-NLCs) was 71.2 nm (NLC-C1) and 91.93 nm (NLC-C2). The particle had negative zeta potential values of -31.9 mV (NLC-C1) and -44.5 mV (NLC-C2). Type I anaphylactoid reaction in the animal model is significantly reduced by cedrol and cedrol-NLC. This in vivo activity of cedrol resulted that cedrol suppressed compound 48/80-induced peritoneal mast cell degranulation and histamine release from mast cells. Furthermore, compound 48/80-evoked Ca2+ uptake into mast cells was reduced in a dose-dependent manner by cedrol and cedrol-NLC. Studies confirmed that the inhibition of type I anaphylactoid response in vivo in mice and compound 48/80-induced mast cell activation in vitro are greatly enhanced by the loading of cedrol into the NLCs. The safety of cedrol and CR-NLC was evaluated as selectivity index (SI) with prednisolone and cromolyn sodium as positive control. SI of CR-NLC-C2 was found to be 11.5-fold greater than both prednisolone and cromolyn sodium.

CONCLUSION

Administration of CR-NLC 24 hours before the onset of anaphylaxis can prevent an anaphylactoid reaction. NLCs could be a promising vehicle for the oral delivery of cedrol to protect anaphylactic reactions.

Preparation and characterization of minoxidil loaded nanostructured lipid carrier gel for effective treatment of alopecia

In the present work attempts have been made to prepare the nanostructured lipid carrier (NLC) gel, by using minoxidil, which is preferably used in case of Alopecia, i.e. baldness pattern as a effective drug. The nine different formulations of Minoxidil-NLC (NLC1-NLC9) were prepared using solid and liquid lipids with Cholesterol and Soya lecithin in different concentrations by the melt dispersion ultrasonication method. Properties of NLC1-NLC9 such as the particle size and its distribution, the scanning electron microscopy (SEM), the drug entrapment efficiency (EE), and the drug release behavior were investigated. The nanoparticulate dispersion was suitably gelled and characterized with respect to drug content, pH, spreadability, rheology, and in vitro release. Safety of the NLC-based gel was assessed using primary skin irritation studies. The formulated NLC3 was spherical in shape, with average particle size of 280 nm, zeta potential of -42.40 mV and entrapment efficiency of 86.09%. Differential Scanning Calorimeter (DSC) measurements revealed that imperfect crystallization occurred in the inner core of the NLC particles. The drug release behavior from the NLC displayed a biphasic drug release pattern with burst release at the initial stage followed by sustained release. These results indicated that the NLC3 is a suitable carrier of minoxidil with improved drug loading capacity and controlled drug release properties. It has been observed that NLC gel produces the gel with good consistency, homogeneity, spreadability and rheological behavior. The developed NLC-based gel showed faster onset and elicited prolonged activity up to 16 h. The present study concluded that the NLC-based gel containing minoxidil dissolved in a mixture of solid lipid and liquid lipid in the nanoparticulate form helped us to attain the objective of faster onset yet prolonged action as evident from in vitro release.

Preparation, characterization, and in vivo pharmacokinetics of nanostructured lipid carriers loaded with oleanolic acid and gentiopicrin

Background

The purpose of this work was to develop nanostructured lipid carriers (NLCs) loaded simultaneously with oleanolic acid and gentiopicrin.

Methods

An aqueous dispersion of NLCs was prepared successfully using a film-ultrasonic method, with glycerin monostearate as the solid lipid and oleic acid as the liquid lipid. Poloxamer 188 was used as the surfactant. A central composite design was used to optimize the technologic parameters. The characteristics of the NLCs were then investigated.

Results

The encapsulation efficiency was 48.34% ± 2.76%, drug loading was 8.06% ± 0.42%, particle size was 111.0 ± 1.56 nm, polydispersity index was 0.287 ± 0.01, and zeta potential was −23.8 ± 0.36 mV for the optimized NLCs. The other physicochemical properties were characterized by transmission electron microscopy and differential scanning calorimetry. Drug release followed first-order kinetics and release studies confirmed that oleanolic acid and gentiopicrin fitted a sustained-release model. Compared with NLCs loaded with oleanolic acid or gentiopicrin alone, NLCs loaded with both oleanolic acid and gentiopicrin produced drug concentrations which persisted for a significantly longer time in plasma, with a linear decrement following second-order kinetics. Aspartate and alanine aminotransferase levels were significantly lower on exposure to NLCs loaded with both oleanolic acid and gentiopicrin than in negative controls.

Conclusion

The results of this study confirm that oleanolic acid and gentiopicrin can be loaded simultaneously into NLCs. Compared with oleanolic acid and gentiopicrin loaded alone, sustained release and protective effects against hepatic injury were observed using NLCs loaded with both oleanolic acid and gentiopicrin.

In vitro characterization and in vivo evaluation of nanostructured lipid curcumin carriers for intragastric administration

Background

Curcumin has a variety of pharmacological effects. However, poor water solubility and low oral bioavailability limit its clinical utility. A delivery system for nanostructured lipid carriers has been reported to be a promising approach to enhancing the oral absorption of curcumin. The aim of the present study was to investigate the pharmacokinetics, tissue distribution, and relative bioavailability of curcumin in rats after a single intragastric dose of a nanostructured lipid curcumin carrier formulation.

Methods

Nanostructured lipid curcumin carriers were prepared using the ethanol dripping method and characterized in terms of the particle size, polydispersity index, zeta potential, differential scanning calorimetry, drug-loading capacity, encapsulation efficiency, and in vitro release. The pharmacokinetics and tissue distribution of nanostructured lipid curcumin carriers and curcumin suspension were compared after intragastric administration.

Results

Nanostructured lipid curcumin carriers showed a significantly higher peak plasma concentration (564.94 ± 14.98 ng/mL versus 279.43 ± 7.21 ng/mL, P < 0.01), a shorter time taken to reach peak plasma concentration (0.5 ± 0.01 hour versus 1.0 ± 0.12 hour, P < 0.01), and a greater AUC_0–∞ (820.36 ± 25.11 mg × hour/L versus 344.11 ± 10.01 mg × hour/L, P < 0.05) compared with curcumin suspension. In the tissue distribution studies, curcumin could be detected in the spleen, heart, liver, kidneys, lungs, and brain. Following intragastric administration of the nanostructured lipid curcumin carrier formulation, tissue concentrations of curcumin also increased, especially in the brain. The nanostructured lipid curcumin carrier formulation improved the ability of curcumin to cross the blood–brain barrier, with an 11.93-fold increase in the area under the curve achieved in the brain when compared with curcumin suspension.

Conclusion

The nanostructured lipid carrier formulation significantly improved the oral bioavailability of curcumin and represents a promising method for its oral delivery.