Oleic acid-loaded nanostructured lipid carrier inhibit neutrophil activities in the presence of albumin and alleviates skin inflammation

Aim

This paper reports on the incorporation of oleic acid (OA) within nanostructured lipid carriers (OA-NLC) to improve the anti-inflammatory effects in the presence of albumin.

Materials and methods

NLCs produced via hot high-shear homogenization/ultrasonication were characterized in terms of particle size, zeta potential, and toxicity. We examined the effects of OA-NLC on neutrophil activities. Dermatologic therapeutic potential was also elucidated by using a murine model of leukotriene B4-induced skin inflammation.

Results

In the presence of albumin, OA-NLC but not free OA inhibited superoxide generation and elastase release. Topical administration of OA-NLC alleviated neutrophil infiltration and severity of skin inflammation.

Conclusion

OA incorporated within NLC can overcome the interference of albumin, which would undermine the anti-inflammatory effects of OA. OA-NLC has potential therapeutic effects in topical ointments.

[Construction of artesunate nanoparticles modified by hyaluronic acid and cell-penetrating peptides and its inhibitory effect on cancer cells in vitro]

Hyaluronic acid (HA) and cell-penetrating peptide (CPP) R6H4-SA modified artesunate nanostructured lipid carrier (HA-R6H4-NLC/ART) for anti-tumor therapy was prepared. The physicochemical properties and in vitro drug release of HA-R6H4-NLC/ART were evaluated, and the uptake and cytotoxicity of liver cancer HepG2 cells were studied. The results showed that HA-R6H4-NLC/ART was spherical like in appearance, and the average particle size was about 160 nm. In vitro release experiments showed that the drug delivery system had sustained release characteristics. Cell results showed that, in slightly acidic environment, pH sensitive CPP R6H4-SA mediated cellular uptake of nanoparticles was significantly higher than that of non-sensitive peptide R8-SA. Meanwhile, HA-R6H4-NLC/ART had a targeting effect on HepG2 cells, and the HA receptor saturation experiment showed that the endocytosis of HA-R6H4-NLC/ART was mediated by the HA receptor on the cell surface. As compared with the unmodified or R6H4-SA single modified group, HA and R6H4-SA co-modified HA-R6H4-NLC/ART significantly improved the cell uptake and had a stronger anti-tumor effect under the conditions of the slightly acid environment and hyaluronidase degradation. The above results showed that hyaluronic acid and CPP R6H4-SA co-modified artesunate nanostructured lipid carrier, which can effectively identify and penetrate the tumor cell membrane into the cell, is a potentially efficient targeting delivery system for anti-tumor drugs.

Curcumin-Loaded Nanostructured Lipid Carrier Modified with Partially Hydrolyzed Ginsenoside

The objective of the present study was to investigate the effect of partially hydrolyzed ginsenoside on the physicochemical properties and in vitro release of curcumin from phospholipid-based nanostructured lipid carrier (NLC). NLC formulas modified with partially hydrolyzed ginsenoside (NLC-PG) were prepared with different amounts of ginsenoside using the conventional hot-melt method. The average particle size of curcumin-loaded NLC-PG ranged from 150 to 200 nm, and polydispersity index was in the range of 0.101-0.177, indicating monodispersed particle size distribution. Optical microscopy showed no sedimentation or recrystallization of curcumin even at 10,000 μg/ml concentration as NLC-PG in distilled water, indicating significantly enhanced solubility. TEM image showed that the nanoparticles were monodispersed with a multilayered core/shell structure. X-ray diffraction and FTIR spectroscopy showed that curcumin was amorphous in the NLC-PG, and there was no interaction between curcumin and the excipients. In vitro release study using simulated gastric/intestinal fluid media revealed that the release rate (J_ss) of curcumin from the NLC-PG increased as a function of the ginsenoside content in the lipid carrier. Moreover, the J_ss of curcumin kept gradually increasing in the presence of lipase, whereas in the presence of viscozyme, it sharply increased until the ginsenoside content reached 9.09% and subsequently plateaued. Partially hydrolyzed ginsenoside increased the J_ss of curcumin from curcumin-loaded NLC-PG and therefore may be useful for improving the bioavailability of curcumin.

The Delivery Strategy of Paclitaxel Nanostructured Lipid Carrier Coated with Platelet Membrane

Strategies for the development of anticancer drug delivery systems have undergone a dramatic transformation in the last few decades. Lipid-based drug delivery systems, such as a nanostructured lipid carrier (NLC), are one of the systems emerging to improve the outcomes of tumor treatments. However, NLC can act as an intruder and cause an immune response. To overcome this limitation, biomimicry technology was introduced to decorate the surface of the nanoparticles with various cell membrane proteins. Here, we designed paclitaxel (PT)-loaded nanostructured lipid carrier (PT-NLC) with platelet (PLT) membrane protein because PLT is involved with angiogenesis and interaction of circulating tumor cells. After PLT was isolated from blood using the gravity-gradient method and it was used for coating PT-NLC. Spherical PT-NLC and platelet membrane coated PT-NLC (P-PT-NLC) were successfully fabricated with high encapsulation efficiency (EE) (99.98%) and small particle size (less than 200 nm). The successful coating of PT-NLC with a PLT membrane was confirmed by the identification of CD41 based on transmission electron microscopy (TEM), western blot assay and enzyme-linked immunosorbent assay (ELISA) data. Moreover, the stronger affinity of P-PT-NLC than that of PT-NLC toward tumor cells was observed. In vitro cell study, the PLT coated nanoparticles successfully displayed the anti-tumor effect to SK-OV-3 cells. In summary, the biomimicry carrier system P-PT-NLC has an affinity and targeting ability for tumor cells.

Nanostructured Lipid Carrier of Propofol: a Promising Alternative to Marketed Soybean Oil-Based Nanoemulsion

Nanostructured lipid carrier (NLC) of propofol was formulated using hot emulsification-probe sonication method for improvising its parenteral delivery by reducing pain on injection and risk of microbial contamination. The formulated NLC was optimized using central composite design and evaluated for particle size, zeta potential, morphology, free propofol concentration, hemocompatibility, stability, pain on injection, in vivo anesthetic activity, pharmacokinetics, and antimicrobial effectiveness in comparison to the marketed formulation. Optimized NLCs exhibited globule size, less than 200 nm, and zeta potential - 24.1 mV, indicating its stability. TEM images confirmed the spherical shape and nanosize (200 nm) of optimized NLCs. Free propofol concentration was also found to be 40% lesser than marketed formulation. Optimized NLC was found to be non-hemolytic. Rat paw-lick study showed that propofol NLC was significantly less painful compared to the marketed formulation. Anesthetic potential and pharmacokinetics of optimized NLCs were found to be similar to that of the marketed formulation. NLC was found stable in long-term storage under room temperature. Antimicrobial effectiveness study showed that propofol NLC suppressed microbial growth to a greater extent as compared to the marketed formulation. Hence, the developed propofol NLCs appeared to be clinically useful as a potential carrier for propofol delivery.

Systemic Design and Evaluation of Ticagrelor-Loaded Nanostructured Lipid Carriers for Enhancing Bioavailability and Antiplatelet Activity

Ticagrelor (TGL), a P2Y12 receptor antagonist, is classified as biopharmaceutics classification system (BCS) class IV drug due to its poor solubility and permeability, resulting in low oral bioavailability. Nanostructured lipid carriers (NLC) are an efficient delivery system for the improvement of bioavailability of BCS class IV drugs. Hence, we prepared TGL-loaded NLC (TGL-NLC) to enhance the oral bioavailability and antiplatelet activity of TGL with a systemic design approach. The optimized TGL-NLC with Box-Behnken design showed a small particle size of 87.6 nm and high encapsulation efficiency of 92.1%. Scanning electron microscope (SEM), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) were performed to investigate the characteristics of TGL-NLC. Furthermore, TGL-NLC exhibited biocompatible cytotoxicity against Caco-2 cells. Cellular uptake of TGL-NLC was 1.56-fold higher than that of raw TGL on Caco-2 cells. In pharmacokinetic study, the oral bioavailability of TGL-NLC was 254.99% higher than that of raw TGL. In addition, pharmacodynamic study demonstrated that the antiplatelet activity of TGL-NLC was superior to that of raw TGL, based on enhanced bioavailability of TGL-NLC. These results suggest that TGL-NLC can be applied for efficient oral absorption and antiplatelet activity of TGL.

[Oral absorption of asiatic acid nanoparticles modified with PEG]

A solvent diffusion method was used to prepare pegylated asiatic acid (AA) loaded nanostructured lipid carriers (p-AA-NLC), and the ligated intestinal circulation model was established to observe the absorption and distribution in small intestine. The concentration of AA in bile after oral administration of p-AA-NLC was detected by HPLC in healthy SD rats to indirectly evaluate the oral absorption promoting effect of PEG-modified namoparticles. The results showed that the penetration of p-AA-NLC was enhanced significantly and the transport capacity was increased greatly in small intestinal after PEG modification. As compared with the normal nanoparticles (AA-NLC), the Cmax of the drug excretion was increased by 76%, the time to reach the peak (tmax ) was decreased and the elimination half-life t1/2 was doubled in the rats after oral administration of p-AA-NLC, and the AUC0→t was 1.5 times of the AA-NLC group, indicating that the oral bioavailability of AA-NLC was significantly improved by hydrophilic modification of PEG.

Improved Stability of Polyglycerol Polyricinoleate-Substituted Nanostructured Lipid Carrier Cholecalciferol Emulsions with Different Carrier Oils

Cholecalciferol, also known as vitamin D₃ , is a recognized therapeutic agent for treatment of bone diseases and cancer. However, instability and poor bioavailability have been major challenges for delivering Vitamin D₃ . The objective of this study was to formulate improved nanostructured lipid carrier (NLC) vitamin D₃ emulsions. We tested the effect of different carrier oils and the use of a solid lipid nanoparticle emulsifier, polyglycerol polyricinoleate (PGPR) on the stability of the vitamin D₃ emulsions. In contrast to the control that used glyceryl monostearate (GMS) the PGPR substitution resulted in relatively small particle sizes (0.30 to 0.43 μm), with high absolute value of zeta potentials (39.5 to 67.8 mV) and high encapsulation efficiency (85.2% to 90.4%). The stability of the NLC emulsions against environmental stresses was evaluated under varying conditions of ionic strength, pH, freeze-thaw cycles, and storage at different temperatures. Although NLC emulsions were stable at high ionic strengths, they were found to be unstable at low pH (<3), which led to aggregation and coalescence of emulsion droplets. In case of freeze-thaw stress, although relatively stable compared to control NLC, the PGPR substituted groups exhibited a slight increase in particle size and a decrease in zeta potential when the cycle was repeated five times. Additionally, we found that PGPR-substituted emulsions showed higher liquid dispersion stability than controls at 25 and 65 °C. Thus, we have formulated a modified NLC vitamin D₃ emulsion that can be widely used in the food industry. PRACTICAL APPLICATION: Vitamin D₃ , an essential micronutrient, is often added as supplements in food products and beverages for added health benefits. However, the stability of vitamin D₃ emulsions that are used in the preparation of such products has been a major concern. We have developed a modified emulsion that has improved stability against environmental stresses. We believe, in future, this formulation can be efficiently used in the food industry.

Regulation of inflammatory response of macrophages and induction of regulatory T cells by using retinoic acid-loaded nanostructured lipid carrier

Immunomodulatory function of all-trans retinoic acid (ATRA) has been gathering much attention for the therapy of autoimmune diseases. ATRA is a chemically unstable molecule which requires proper formulation for targeted delivery. Here we examined nanostructured lipid carrier (NLC) for the formulation of ATRA. NLC is a representative nanoparticle formulation especially suited for oral delivery. We established the preparation procedures of ATRA-containing NLC (NLC-RA) which minimizes the degradation of ATRA during the preparation process. NLC-RA thus obtained was taken up by macrophages and induced anti-inflammatory response via suppressing NF-κB signaling as well as via enhancing the production of anti-inflammatory cytokines. Moreover, NLC-RA enhanced differentiation of naïve T cells to regulatory T cells in the co-culture system with dendritic cells. These results suggest that NLC-RA is a promising alternative therapy for the autoimmune diseases especially intestinal bowel disease.

[Acute and chronic toxicity of 0.5% podophyllotoxin-loaded nanostructured lipid carriers to vaginal mucosa in rabbits and rats]

OBJECTIVE

To test the acute and chronic toxicity of topical application of 0.5% podophyllotoxin-loaded nanostructured lipid carriers (POD-NLC) to the vaginal mucosa.

METHODS

Twelve New Zealand rabbits were randomized into 3 groups and subjected to daily topical applications of normal saline (control group), 0.5% podophyllotoxin tincture (POD-T) or 0.5% POD-NLC on the vaginal mucosa for 10 consecutive days, and the pathological changes in the mucosa were graded using the Eckstein scoring system.The acute toxicity of POD-NLC was tested in 20 SD female rats, which received intravaginal administration of POD-NLC or vehicle for 3 times within 24 h; After 14 days of continuous observation, the rats were dissected for calculating the viscera coefficient.For testing the chronic toxicity of POD-NLC, 80 SD female rats were randomized into 4 groups and subjected to daily intravaginal administration of the vehicle or POD-NLC at low, moderate or high doses for 13 consecutive weeks.The rats were weighed once a week and at the end of the experiment, 2/3 of the rats from each group were sacrificed to collect blood samples, calculate the viscera coefficient, and examine the pathological changes in the liver.The remaining 1/3 rats were observed for another 2 weeks without further drug treatment and the same examinations were performed.

RESULTS

In the rabbits, 0.5% POD-NLC elicited only mild irritation while POD-T caused moderate irritation of the vaginal mucosa.In the acute toxicity test, the organ coefficients were comparable between the rats treated with the vehicle and POD-NLC (P&gt;0.05).Long-term intravaginal administration of POD-NLC did not produce significant changes in the behavior, activity, body weight, blood biochemical profiles or organ coefficient as compared with the vehicle control group (P&gt;0.05).

CONCLUSIONS

Intravaginal administration of 0.5% POD-NLC causes very mild irritation without obvious acute or chronic toxicity to the vaginal mucosa in rabbits and rats.

Nanostructured lipid carriers-based thermosensitive eye drops for enhanced, sustained delivery of dexamethasone

AIM

Nanostructured lipid carriers in-gel (NLCs-gel) were prepared to enhance and improve the ocular delivery of dexamethasone. Materials & methods: NLCs containing dexamethasone prepared by high-pressure homogenization were characterized and dispersed into thermosensitive gels (Pluronic F127 and F68 as gels material). In vitro drug release studies, ocular irritation tests, ex vivo corneal penetration and drug dynamics of NLCs and NLCs-gel were evaluated in aqueous humor.

RESULTS

NLCs-gel exhibited a rapid sol-gel transition at 34.4°C and presented nano-sized, narrowly distributed particles. Corneal penetration studies revealed steady sustained drug release (Ritger-Peppas); NLCs-gel increased ocular bioavailability by prolonging precorneal retention time and improving corneal permeation.

CONCLUSION

These findings suggest developing NLCs-gel for potential treatment of posterior segment eye diseases.

Cell penetrating peptides functionalized gambogic acid-nanostructured lipid carrier for cancer treatment

Tumor-targeted delivery is considered a crucial component of current anticancer drug development and is the best approach to increase the efficacy and reduce the toxicity. Nanomedicine, particularly ligand-based nanoparticles have shown a great potential for active targeting of tumor. Cell penetrating peptide is one of the promising ligands in a targeted cancer therapy. In this study, the gambogic acid-loaded nanostructured lipid carrier (GA-NLC) was modified with two kinds of cell penetrating peptides (cRGD and RGERPPR). The GA-NLC was prepared by emulsification and solvent evaporation method and coupled with cRGD, RGERPPR, and combination cRGD and RGERPPR to form GA-NLC-cRGD, GA-NLC-RGE, and GA-NLC-cRGD/RGE, respectively. The formulations were characterized by their particle size and morphology, zeta potential, encapsulation efficiency, and differential scanning calorimetry. In vitro cytotoxicity and cellular uptake study of the formulations were performed against breast cancer cell (MDA-MB-231). Furthermore, in vivo biodistribution and antitumor activity of the formulations were determined by in vivo imaging and in tumor-bearing nude mice, respectively. The result of in vitro cytotoxicity study showed that GA-NLC-RGE exhibited a significantly higher cytotoxicity on MDA-MB-231 as compared with GA-NLC and GA-Sol. Similarly, RGE-Cou-6-NLC showed remarkably higher uptake by the cells than other NLCs over the incubation period. The in vivo imaging study has demonstrated that among the formulations, the RGE-decorated DiR-NLC were more accumulated in the tumor site. The in vivo antitumor activity revealed that RGE-GA-NLC inhibits the tumor growth more efficiently than other formulations. In conclusion, RGERPPR has a potential as an effective carrier in targeting drug delivery of anticancer agents.

Sterically Stabilized RIPL Peptide-Conjugated Nanostructured Lipid Carriers: Characterization, Cellular Uptake, Cytotoxicity, and Biodistribution

As a platform for hepsin-specific drug delivery, we previously prepared IPLVVPLRRRRRRRRC peptide (RIPL)-conjugated nanostructured lipid carriers (RIPL-NLCs) composed of Labrafil® M 1944 CS (liquid oil) and Precirol® ATO 5 (solid lipid). In this study, to prevent the recognition by the mononuclear phagocyte system, polyethylene glycol (PEG)-modified RIPL-NLCs (PEG-RIPL-NLCs) were prepared using PEG3000 at different grafting ratios (1, 5, and 10 mole %). All prepared NLCs showed a homogeneous dispersion (130⁻280 nm), with zeta potentials varying from -18 to 10 mV. Docetaxel (DTX) was successfully encapsulated in NLCs: encapsulation efficiency (93⁻95%); drug-loading capacity (102⁻109 µg/mg). PEG-RIPL-NLCs with a grafting ratio of 5% PEG or higher showed significantly reduced protein adsorption and macrophage phagocytosis. The uptake of PEG(5%)-RIPL-NLCs by cancer cell lines was somewhat lower than that of RIPL-NLCs because of the PEG-induced steric hindrance; however, the uptake level of PEG-RIPL-NLCs was still greater than that of plain NLCs. In vivo biodistribution was evaluated after tail vein injection of NLCs to normal mice. Compared to RIPL-NLCs, PEG(5%)-RIPL-NLCs showed lower accumulation in the liver, spleen, and lung. In conclusion, we found that PEG(5%)-RIPL-NLCs could be a promising nanocarrier for selective drug targeting with a high payload of poorly water-soluble drugs.

Cascaded Aptamers-Governed Multistage Drug-Delivery System Based on Biodegradable Envelope-Type Nanovehicle for Targeted Therapy of HER2-Overexpressing Breast Cancer

Tumor-specific therapeutic platforms with improved targeting efficacy and minimized side effect are crucial in cancer therapy. Capitalizing on the recognition capability and biocompatibility of aptamers, we herein designed a multistage targeted drug-delivery system using multiple biodegradable molecules-enveloped nanovehicle that can be employed to efficiently treat human epithelial growth factor receptor (HER2)-overexpressing breast cancer. In this nanovehicle, two aptamers respectively specific to HER2 and ATP were organized in a hierarchical manner. The outmost HER2 aptamer (HB5) governs the recognition to HER2 protein overexpressed in SK-BR-3 cell lines, while the ATP aptamer incorporated with anticancer drug (-)-epigallocatechin gallate (EGCG) and protamine sulfate in the inner core functions as a switch of drug release in response to abundant intracellular ATP. The targeting and drug locker aptamers were cascaded for active targeting effect and stimuli responsiveness, guaranteeing the site-specific drug transportation and endogenous species-triggered drug release inside the tumor cells. Moreover, nanostructured lipid carriers (NLCs) were constructed to wrap and stabilize the loosely bounded ternary complex, minimizing premature drug leakage potentially encountered by the biomolecule assembled nanocarriers. This multiple biomolecules-enveloped nanovehicle demonstrated improved inhibitory actions on tumor growth and minimum side effect to normal organs and tissues both in vitro and in vivo. The presented nanovehicle built from recognition and therapeutic components in a nontoxic framework offered a promising drug-delivery platform with transport precision and biological safety.

NLCs as a potential carrier system for transdermal delivery of forskolin

Nanostructured lipid carriers (NLC) composed of the substances generally recognized as safe (GRAS) were obtained by using a hot high-pressure homogenization technique (HPH). The influence of the number of homogenization cycles and concentration of a decyl glucoside surfactant on the NLC properties were studied. The system's stability was assessed by macroscopic observation, light backscattering and zeta potential measurements. NLC particle size was measured using dynamic light scattering (DLS). The kinetically stable formulations were loaded with forskolin and selected for in vitro drug permeation study using the Franz cell method. Concentration of forskolin in the receptor solution (i.e. ethanol/PBS mixture) was analyzed with high performance liquid chromatography (HPLC) with UV detection. The obtained results have shown that NLC formulations could be used as effective carriers for forskolin permeation through the skin.

A Nanostructured Lipid Carrier for Delivery of a Replicating Viral RNA Provides Single, Low-Dose Protection against Zika

Since the first demonstration of in vivo gene expression from an injected RNA molecule almost two decades ago,¹ the field of RNA-based therapeutics is now taking significant strides, with many cancer and infectious disease targets entering clinical trials.² Critical to this success has been advances in the knowledge and application of delivery formulations. Currently, various lipid nanoparticle (LNP) platforms are at the forefront,³ but the encapsulation approach underpinning LNP formulations offsets the synthetic and rapid-response nature of RNA vaccines.⁴ Second, limited stability of LNP formulated RNA precludes stockpiling for pandemic readiness.⁵ Here, we show the development of a two-vialed approach wherein the delivery formulation, a highly stable nanostructured lipid carrier (NLC), can be manufactured and stockpiled separate from the target RNA, which is admixed prior to administration. Furthermore, specific physicochemical modifications to the NLC modulate immune responses, either enhancing or diminishing neutralizing antibody responses. We have combined this approach with a replicating viral RNA (rvRNA) encoding Zika virus (ZIKV) antigens and demonstrated a single dose as low as 10 ng can completely protect mice against a lethal ZIKV challenge, representing what might be the most potent approach to date of any Zika vaccine.

Ubidecarenone-Loaded Nanostructured Lipid Carrier (UB-NLC): Percutaneous Penetration and Protective Effects Against Hydrogen Peroxide-Induced Oxidative Stress on HaCaT Cells

The objective of the investigation was to evaluate the percutaneous penetration of a ubidecarenone-loaded nanostructured lipid carrier (UB-NLC) and to illuminate the protective effects of UB-NLC for amelioration of hydrogen peroxide-induced oxidative damage on HaCaT cells. Ubidecarenone (UB) was encapsulated in a nanostructured lipid carrier (NLC), which was manufactured by homogenization. The morphological and dimensional properties of the prepared UB-NLC were studied by freeze-fracture transmission electron microscopy (FF-TEM) and photon correlation spectroscopy (PCS). Percutaneous penetration of UB-NLC was carried out by the Franz diffusion cells method. The change of cellular morphology was identified through a non-invasive time-lapse imaging system. The assessment was achieved via the evaluation of the levels of oxidative stress markers: reactive oxygen species (ROS), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and malondialdehyde (MDA). Percutaneous penetration of UB loaded in NLC formulation was enhanced in comparison to free UB. Preincubation of HaCaT cells with UB-NLC attenuated the level of intracellular generation of ROS. Lipid peroxidation was diminished by UB-NLC via inhibition of MDA formation. Pretreatment of cells with UB-NLC reestablished the activity of cellular antioxidant enzymes (SOD and GSH-PX). On the basis of the investigation conducted, results suggest that formulating UB as NLC is advantageous for topical delivery and treatment of oxidative stress-induced human diseases.

Ocular Delivery System for Propranolol Hydrochloride Based on Nanostructured Lipid Carrier

One drawback of traditional forms of medical ocular dosage is drug dilution by tear; moreover, drugs are rapidly drained away from pre-corneal cavity by tear flow and lacrimo-nasal drainage. Prolonging contact time with different strategies and mucoadhesive vehicles will help to continuously deliver drugs to the eyes. For this study, we prepared and evaluated the effects of a nanostructure lipid carrier (NLC) on propranolol hydrochloride as a hydrophilic drug model for rabbit corneal permeation. Propranolol hydrochloride NLC was prepared using cold homogenization. The lipid was melted, then the drug and surfactant were dispersed and stirred into the melted lipid. This fused lipid phase was scattered in aqueous solution containing the cosurfactant at 4 °C and then homogenized. We evaluated particle size, drug loading, drug release, and NLC permeability through rabbit cornea as well as the formula’s effect on the cornea. Our results show that drug loading efficiency depended on the surfactant/lipid ratio (S/L) and the percentages of liquid lipid and Transcutol (Gattefosse, Saint-Priest, France) (as solubilizer). Drug release data were evaluated with the Higuchi model and a significant correlation was shown between the S/L ratio and the amount of drug released after 4 and 48 h. NLC formulations improved propranolol hydrochloride permeation. We conclude that the effect of the NLC formulations was due to mucoadhesive and film forming properties.

Lipid nanoparticles (SLN & NLC) for delivery of vitamin E: a comprehensive review

The antioxidative and photoprotective properties of vitamin E have caused it to be included as an active agent in various pharmaceutical and cosmetic products. However, its lipophilicity, chemical instability and poor skin penetration have limited the effectiveness of these formulations. For that reason, many attempts to include it in different drug delivery systems have been made. In recent decades, lipid nanoparticles have received special attention due to their advantages of compatibility with the skin, ability to enhance penetration of drugs in the stratum corneum, protection of the encapsulated substance against degradation induced by the external medium and control of drug release. This work reviews the current status of the encapsulation of vitamin E in lipid nanoparticles. We describe the most important methods for obtaining and characterizing lipid nanoparticles containing vitamin E (LNP-VE), various techniques for the evaluation of vitamin E's properties after encapsulation, the main in vitro and in vivo studies of the potential effectiveness or toxicity of LNP-VE, the formulations and stability studies of this delivery system, the commercial products based on LNP-VE and the regulatory aspects related to lipid nanoparticles. Finally, we discuss the most relevant advantages of encapsulating vitamin E in such particles and critical aspects that still demand attention to enhance the potential of solid lipid nanoparticles to deliver vitamin E.

[Preparation and evaluation of dioscin nanostructured lipid carriers]

In this report, a heat and high-pressure homogenization method was used to prepare dioscin nanostructured lipid carriers, and the formulation of dioscin nanostructured lipid carriers was optimized by central composite design-response surface methodology. In vitro evaluation data showed that the preparation of dioscin nanostructured lipid carriers under optimal process by central composite design-response surface methodology had a spherical shape and homogeneous size distribution, with a particle size of (90.9±0.6) nm, a polydispersity index of (0.253±0.07), Zeta potential of (-45.7±0.5) mV, encapsulation efficiency of (90.2±0.5)%, and the drug loading of (23.30±0.10)%. These results clearly indicate that the preparation of dioscin nanostructured lipid carriers made with the heat and high-pressure homogenization method have very good physical and chemical properties, suitable for therapeutic applications.

An Update of Patents, Preclinical and Clinical Outcomes of Lipid Nanoparticulate Systems

BACKGROUND

Lipid nanoparticles have attracted increased degree of scientific and commercial attention in the last decade. The lipidic nanoparticles have emerged as a potential alternative to other nano-scale systems due to their various advantages over them and also due to overcoming the shortcomings of the already available colloidal systems like liposomes, niosomes and polymeric nanoparticles.

DESCRIPTION

These have been investigated for delivery of macromolecules, genes, siRNA and other therapeutic agents for oral, topical, parenteral administration and target site specific delivery for various diseases like cancer, ocular diseases and brain disorders. The lipid nanoparticles have evolved from SLNs, then NLCs and lipid drug conjugates overcoming any issues related to production and formulation and adding advantages, if any. The current review article focuses on the lipid nanoparticles, their formulation approaches and current advancements in the field through recent clinical trials and patents. This manuscript embodies various patents, preclinical and clinical aspects related to the lipidic nanocarriers.

CONCLUSION

Over the years the lipidic nanoparticulate systems have evolved as significant carriers for improved therapeutics and in diagnostic field. The large number of patents and preclinical trials in the recent years suggests that these systems will find immense potential in near future.

T2-Weighted Magnetic Resonance Imaging of Hepatic Tumor Guided by SPIO-Loaded Nanostructured Lipid Carriers and Ferritin Reporter Genes

Nowadays, there is a high demand for supersensitive contrast agents for the early diagnostics of hepatocarcinoma. It has been recognized that accurate imaging information is able to be achieved by constructing hepatic tumor specific targeting probes, though it still faces challenges. Here, a AGKGTPSLETTP peptide (A54)-functionalized superparamagnetic iron oxide (SPIO)-loaded nanostructured lipid carrier (A54-SNLC), which can be specifically uptaken by hepatoma carcinoma cell (Bel-7402) and exhibited ultralow imaging signal intensity with varied Fe concentration on T2-weighted imaging (T2WI), was first prepared as an effective gene carrier. Then, an endogenous ferritin reporter gene for magnetic resonance imaging (MRI) with tumor-specific promoter (AFP-promoter) was designed, which can also exhibit a decrease in signal intensity on T2WI. At last, using protamine as a cationic mediator, novel ternary nanoparticle of A54-SNLC/protamine/DNA (A54-SNPD) as an active dual-target T2-weighted MRI contrast agent for imaging hepatic tumor was achieved. Owing to the synergistic effect of A54-SNLC and AFP-promoted DNA targeting with Bel-7402 cells, T2 imaging intensity values of hepatic tumors were successfully decreased via the T2 contrast enhancement of ternary nanoparticles. It is emphasized that the novel A54-SNPD ternary nanoparticle as active dual-target T2-weighted MRI contrast agent were able to greatly increase the diagnostic sensitivity and specificity of hepatic cancer.

[Preparation of tanshinone ⅡA loaded nanostructured lipid carrier and its in vitro transdermal permeation characteristics]

To prepare tanshinone ⅡA loaded nanostructured lipid carrier (Tan ⅡA-NLC), and study its in vitro transdermal permeation characteristics. The Tan ⅡA-NLC was prepared by high pressure homogenization technology and optimized by Box-Behnken design-response surface method, and it was characterized in terms of morphology, particle size, zeta potention, et al. The transdermal permeation of Tan ⅡA-NLC was evaluated by using Franz diffusion cells. The results showed that, the optimal formulation was as follows: drug/lipid materials ratio 88, GMS/MCT ratio 2, emulsifier concentration 1%, average particle size (182±14) nm, polydispersity index PDI (0.190 6±0.024 5), zeta potential (－27.8± 5.4) mV, encapsulation efficiency EE (86.44%±9.26%) and drug loading DL (0.98%±0.18%), respectively. The in vitro transdermal permeation results showed that as compared with Tan ⅡA solution, Tan ⅡA-NLC had lower transdermal permeation amount after applying drug for 24 h, but its retention in the epidermis was 3.18 times that of solution. These results indicated that the prepared Tan ⅡA-NLC could effectively increase the regention of Tan ⅡA in the epidermis, and had a broad application prospect.

[Preparation of isopsoralen loaded nanostructured carrier and its in vitro transdermal permeation characteristics]

To increase the permeation and retention of isopsoralen in skin, and improve its bioavailability.Isopsoralen loaded nanostructure liquid carrier (IPRN-NLC) was prepared by high pressure homogenization andoptimized by orthogonal experiment with the encapsulation efficiency, drug loading and average particle size as the evaluation indexes. The in vitro transdermal permeation of IPRN-NLC was evaluated by Franze diffusion cells.The results showed that solid-liquid lipid ratio of optimum IPRN-NLC formulation was 7∶3,drug-lipid ratio of 1∶30, 1% surfactant. Under these conditions, IPRN-NLC had an average encapsulation of （90.25±0.73）%,drug loading of （1.56±0.27）% and an average particle size of (305±1.57) nm.The in vitro transdermal permeation results showed that IPRN-NLC could increase the amount of IPRN permeated though skin, with 3 times of the epidermal retention as compared with IPRN solution. From the results we can know that the IPRN-NLC prepared by high pressure homogenization can improve the permeation andaccumulation of IPRN in the skin, with wide application prospects in the field of transdermal administration.

Acute and subacute toxicity profiles of thymoquinone-loaded nanostructured lipid carrier in BALB/c mice

Background

Thymoquinone (TQ), the predominant active lipophilic component in Nigella sativa seed oil, has a variety of pharmacological properties such as anticancer activities. However, translation of TQ to clinical phase is still not possible due to its hydrophobic properties. This problem can be solved by encapsulating it in nanoformulations to enhance its pharmacological properties. In our previous study, TQ has been successfully encapsulated in a nanostructured lipid carrier (hereinafter referred to as TQNLC) with excellent physiochemical properties such as high encapsulation efficiency, high drug-loading capacity, particle diameter less than 100 nm, and stability up to 2 years. In vitro studies also proved that TQNLC exhibited antiproliferative activity toward breast and cervical cancer cell lines. However, no toxicity profile related to this formulation has been reported. In this study, we determine and compare the in vivo toxicity of both TQNLC and TQ.

Materials and methods

The in vivo toxicity (acute and subacute toxicity) study was carried out by oral administration of TQNLC and TQ to BALB/c mice. Animal survival, body weight, organ weight-to-body weight ratio, hematological profile, biochemistry profile, and histopathological changes were analyzed.

Results

In acute toxicity, TQ that is loaded in nanostructured lipid carrier (NLC) was found to be less toxic than pure TQ. It can be concluded that encapsulation of TQ in lipid carrier minimizes the toxicity of the compound. In the subacute toxicity study, oral administration of 100 mg/kg of TQNLC and TQ did not cause mortality to either male or female but resulted in toxicity to the liver. It is postulated that long-term consumption of TQNLC and TQ may cause toxicity to the liver but not to the extent of altering the functions of the organ. For both treatments, the no observed adverse effect level (NOAEL) was found to be 10 mg/kg/d for mice in both sexes.

Conclusion

For long-term oral consumption, TQ and TQNLC at a dose of 10 mg/kg is safe in mice and does not exert any toxic effect. The results provide safety information of TQNLC, which would further help researchers in clinical use.