Use Of Nanostructured Lipid Carriers Research Articles

How Charge, Size and Protein Corona Modulate the Specific Activity of Nanostructured Lipid Carriers (NLC) against Helicobacter pylori.

The major risk factor associated with the development of gastric cancer is chronic infection with Helicobacter pylori. The available treatments, based on a cocktail of antibiotics, fail in up to 40% of patients and disrupt their gut microbiota. The potential of blank nanostructured lipid carriers (NLC) for H. pylori eradication was previously demonstrated by us. However, the effect of NLC charge, size and protein corona on H. pylori-specific bactericidal activity herein studied was unknown at that time. All developed NLC formulations proved bactericidal against H. pylori. Although cationic NLC had 10-fold higher bactericidal activity than anionic NLC, they lacked specificity, since Lactobacillus acidophilus was also affected. Anionic NLC achieved complete clearance in both H. pylori morphologies (rod- and coccoid-shape) by inducing alterations in bacteria membranes and the cytoplasm, as visualized by transmission electron microscopy (TEM). The presence of an NLC protein corona, composed of 93% albumin, was confirmed by mass spectrometry. This protein corona delayed the bactericidal activity of anionic NLC against H. pylori and hindered NLC activity against Escherichia coli. Overall, these results sustain the use of NLC as a promising antibiotic-free strategy targeting H. pylori.

Quality by design (QbD) optimization of diazepam-loaded nanostructured lipid carriers (NLC) for nose-to-brain delivery: Toxicological effect of surface charge on human neuronal cells

Diazepam is commonly used in the management of epileptic seizures, although it has limitations that can be overcome by using formulations that are easier to administer and capable of directing the drug to the brain. In this field, it has been reported that the use of nanostructured lipid carriers (NLC) via intranasal (or via nose-to-brain) promotes the targeting of drugs to the brain, improving the effectiveness of therapy.The aim of this work was to optimize two diazepam-loaded NLC formulations for nose-to-brain delivery, one with positive surface charge and one with negative surface charge. The quality by design (QbD) approach was used to design the experiments, where the quality target product profile (QTPP), the risk assessment and the critical quality attributes (CQAs) were defined to ensure safety, efficacy and quality of the final formulations.The experiments started with the optimization of critical material attributes (CMAs), related to the ratios of lipids and emulsifiers, followed by the selection of critical process parameters (CPPs), related to the production methods of the diazepam-loaded NLC formulation (ultrasound technique and high-pressure homogenization - HPH). Afterwards, the positive surface charge of the diazepam-loaded NLC was optimized. Finally, the biocompatibility with human neuronal cells of the formulation with a negative surface charge and of the formulation with a positive surface charge was evaluated.The results of the optimization of the CMAs showed that the ratios of lipids and emulsifiers more adequate were 6.7:2.9 and 4.2:0.3 (% w,w), respectively. Regarding the CPPs, HPH was considered the most suitable production method, resulting in an optimized diazepam-loaded NLC formulation (F1C15) with negative surface charge, showing particle size of 69.59 ± 0.22 nm, polydispersity index (PDI) of 0.19 ± 0.00, zeta potential (ZP) of −23.50 ± 0.24 mV and encapsulation efficiency (EE) of 96.60 ± 0.03 %. The optimized diazepam-loaded NLC formulation (F2A8) with positive surface charge had particle size of 124.40 ± 0.84 nm, PDI of 0.17 ± 0.01, ZP of 32.60 ± 1.13 mV and EE of 95.76 ± 0.24 %. In addition, the incorporation of diazepam in NLC resulted in a sustained release of the drug. No significant changes in particle size, PDI, ZP and EE were observed for the formulation F1C15, after 3 months of storage, whereas for formulation F2A8, particle size increased significantly. Biocompatibility studies showed that the formulation F2A8 was more cytotoxic than the formulation F1C15. Thereby, we conclude that the formulation F1C15 is more suitable for targeting the brain, when compared with the formulation F2A8.From the results of these studies, it can be confirmed that the QbD approach is an adequate and central tool to optimize NLC formulations.

Nanostructured lipid base carrier for specific delivery of garlic oil through blood brain barrier against aggressiveness of glioma

Glioblastoma, GBM, is a primary malignant brain tumor and is one of the most difficult-to-treat cancers. The inability of drugs to cross the blood brain barrier (BBB) is the main obstacle for treating brain cancers. The development of drug delivery systems which improve the permeation across the BBB is the focus of this research, specifically the benefits and use of nanostructured lipid carriers (NLC). The anti-inflammatory and anti-tumor activity of garlic oil have been widely studied. However, direct treatment with garlic oil is restricted due to its low bioavailability and the application of drug for brain cancer to improve the efficiency of garlic oil, a NLC was developed as a carrier of garlic oil. The garlic NLC was formulated using the hot high-pressure homogenization technique. The physicochemical properties of the garlic NLC were analyzed using dynamic light scattering. Size of the garlic NLC was 136.8 ± 0.56 nm and the zeta potentials of each formulation were −36.27 ± 0.96 mV and PDI 0.163 ± 0.03. The effect of garlic NLC on the cell viability of the glioma cell was determined using a MTT assay. The garlic NLC had higher efficiency towards inhibiting cell viability of glioma cells compared to free garlic oil. In addition, the effects of the garlic NLC on cell migration and cell invasion were assessed using a Boyden chamber assay. The migration and invasion abilities of garlic NLC treated cells were significantly decreased compared to the control and free garlic oil. Moreover, in vitro BBB was used to test permeation of garlic oil across BBB. Interestingly, garlic NLC could cross the BBB while the free garlic oil could not. Taken together, garlic NLC might be applicable as an alternative therapeutic treatment strategy for brain cancer.

The Prospection of Plant Response to 2-Ketones Released from Nanostructured Lipid Carriers

Nanotechnology plays an important role to increase food production by improving plant performance. Specifically, nanostructured lipid carriers (NLCs) are an important tool for the controlled release of compounds in agriculture. Furthermore, volatile organic compounds (VOCs) have shown an important growth-inducing effect in vegetables. Nevertheless, there is no tool designed for VOC application in agricultural systems. Therefore, the study proposes the use of NLC to the controlled release of VOC to apply in horticulture. The focus of this study was to evaluate the direct impact of 2-ketones released from NLC on Solanum lycopersicum cv Marglobe and Lactuca sativa cv Reina de Mayo. NLCs synthesized with glyceryl tristearate and isopropyl myristate were characterized and used to encapsulate 250 ppm of 2-nonanone, 2-undecanone, or 2-tridecanone. Then, seedlings of S. lycopersicum and L. sativa were exposed to 2-ketones released from NLC for 10 days. Electrolyte leakage, anthocyanin, mass percentage, stomatal aperture, and chlorophyll fluorescence were measured. The data indicated that NLC had a mean size of 205 nm and homogeneity. NLC showed a capacity for the controlled release of 2-ketones, depending on the carbon number of the encapsulated compound. The release of 2-ketones did not have a significant effect on electrolyte leakage and anthocyanin content, but they modulate the percentage of surface elements. The role of 2-ketones to increase stomata aperture and chlorophyll concentration is noted. The results strongly suggest that NLCs are potential carriers for the release of bioactive compounds with potential use in agriculture.

Development of lipid nanoparticles containing the xanthone LEM2 for topical treatment of melanoma

Melanoma is the most aggressive form of skin cancer. Thus, it is important to improve skin cancer treatment efficacy. Topical treatment of skin diseases is a worthy strategy since avoids systemic side effects commonly associated with oral and parenteral drugs administration. The 1-carbaldehyde-3,4-dimethoxyxanthone (LEM2), previously reported as a TAp73 activator, has potent antiproliferative effect on melanoma A375 cell lines. However, it presents poor aqueous solubility and poor bioavailability. Thus, the use of lipid nanoparticles to encapsulate LEM2 seems to be a promising strategy for topical delivery of this drug. In this work, unloaded nanostructured lipid carriers (NLCs) were obtained by hot high-pressure homogenization (HPH) and ultrasonication. These lipid nanoparticles were characterized, and stability tests were performed for 60 days. NLCs were stable and ultrasonication showed to be an easier method to prepare these nanoparticles when compared to hot HPH. Thus, LEM2 was encapsulated in NLCs, using the ultrasonication method, and the final loaded NLCs had a mean particle size suitable for topical application and a high encapsulation efficiency. This formulation seemed to be more cytotoxic against melanoma A375 cell line than unloaded NLCs, which indicates the potential use of NLCs as a carrier to LEM2, improving its efficacy.

A Short Review on the Important Aspects Involved in Preparation, Characterization and Application of Nanostructured Lipid Carriers for Drug Delivery

Background: The development of modern medical and pharmaceutical science has garnered lots of attention due to the development of targeted therapy and precision medicine. The current focus of the researchers is on developing strategies which provide the maximum therapeutic benefits with minimal adverse effects. In this scenario, nanostructured lipid carriers (NLC) have gained prominence because of their ability to improve the therapeutic properties of the drugs. Objective: In this review, we focus on some of the important methods involved in the preparation and characterization of the NLCs. We also discuss the application of NLC as a drug delivery system through different routes of administration and its role in overcoming the physiological and anatomical barriers. Methods: The literature was collected from different scientific browsers like sciencedirect, google scholar, pubmed and a total of 155 articles were read and analysed for the content. Results: The NLC improve the solubility and bioavailability of the drug, prolong the release and residence time and delay clearance. They also protect the drugs from enzymatic degradation and allow them to pass through different anatomical and physiological barriers. Conclusion: Though the use of NLCs has been reported across different therapeutic indications through various routes of administration, this success at the laboratory level has not gone to the next stage. One of the reasons for the failure of NLC formulations to progress to the next level could be due to toxicity caused by the accumulation of NLCs in organs. Hence, in order to utilize this strategy to its maximum potential, further research is inevitable.

Development of Photoprotective Formulations Containing Nanostructured Lipid Carriers: Sun Protection Factor, Physical-Mechanical and Sensorial Properties.

The effects of ultraviolet (UV) radiation emitted by the sun are cumulative and can result in chemical changes such as the generation of reactive oxygen species (ROS), leading to the regular use of sunscreen. As an alternative, the use of antioxidants, such as quercetin, into sunscreen can control these effects and provide additional skin photoprotection. However, quercetin presents low stability and poor permeation, alternatively, the encapsulation in nanoparticles can improve the stability and skin permeation. Thus, this study aimed to develop photoprotective formulations containing nanoencapsulated quercetin, characterize the physical-mechanical and sensorial properties, and evaluate the influence of nanocarriers on sun protection factor (SPF) and the immediate clinical effects. Sunscreen formulations with or without antioxidants in a free form or loaded in nanostructured lipid carriers (NLCs) were developed. After the stability, rheological behavior, texture profile, and in vivo SPF (sun protector factor) evaluation, sixty female participants, aged between 20 and 35years, were enclosed to evaluate the sensorial properties and immediate clinical effects of the formulation in the skin hydration using biophysical and skin imaging techniques. The correlation of rheological behavior, texture profile, and sensory properties enabled the correct choice of formulation ingredients. In addition, the use of NLCs with quercetin significantly improved the SPF in vivo of the developed photoprotective formulation, without increasing the amount of UV filters. Finally, the association of NLCs in the photoprotective formulation showed synergistic effects in the SPF and an improvement in the skin barrier function and hydration.

Nanostructured Lipid Carriers Made of Ω-3 Polyunsaturated Fatty Acids: In Vitro Evaluation of Emerging Nanocarriers to Treat Neurodegenerative Diseases.

Neurodegenerative diseases (ND) are one of the main problems of public health systems in the 21st century. The rise of nanotechnology-based drug delivery systems (DDS) has become in an emerging approach to target and treat these disorders related to the central nervous system (CNS). Among others, the use of nanostructured lipid carriers (NLCs) has increased in the last few years. Up to today, most of the developed NLCs have been made of a mixture of solid and liquid lipids without any active role in preventing or treating diseases. In this study, we successfully developed NLCs made of a functional lipid, such as the hydroxylated derivate of docohexaenoic acid (DHAH), named DHAH-NLCs. The newly developed nanocarriers were around 100 nm in size, with a polydispersity index (PDI) value of <0.3, and they exhibited positive zeta potential due to the successful chitosan (CS) and TAT coating. DHAH-NLCs were shown to be safe in both dopaminergic and microglia primary cell cultures. Moreover, they exhibited neuroprotective effects in dopaminergic neuron cell cultures after exposition to 6-hydroxydopamine hydrochloride (6-OHDA) neurotoxin and decreased the proinflammatory cytokine levels in microglia primary cell cultures after lipopolysaccharide (LPS) stimuli. The levels of the three tested cytokines, IL-6, IL-1β and TNF-α were decreased almost to control levels after the treatment with DHAH-NLCs. Taken together, these data suggest the suitability of DHAH-NLCs to attaining enhanced and synergistic effects for the treatment of NDs.

Nanostructured Lipid Carriers for Delivery of Chemotherapeutics: A Review.

The efficacy of current standard chemotherapy is suboptimal due to the poor solubility and short half-lives of chemotherapeutic agents, as well as their high toxicity and lack of specificity which may result in severe side effects, noncompliance and patient inconvenience. The application of nanotechnology has revolutionized the pharmaceutical industry and attracted increasing attention as a significant means for optimizing the delivery of chemotherapeutic agents and enhancing their efficiency and safety profiles. Nanostructured lipid carriers (NLCs) are lipid-based formulations that have been broadly studied as drug delivery systems. They have a solid matrix at room temperature and are considered superior to many other traditional lipid-based nanocarriers such as nanoemulsions, liposomes and solid lipid nanoparticles (SLNs) due to their enhanced physical stability, improved drug loading capacity, and biocompatibility. This review focuses on the latest advances in the use of NLCs as drug delivery systems and their preparation and characterization techniques with special emphasis on their applications as delivery systems for chemotherapeutic agents and different strategies for their use in tumor targeting.

Overcoming immunogenicity issues of HIV p24 antigen by the use of innovative nanostructured lipid carriers as delivery systems: evidences in mice and non-human primates

HIV is one of the deadliest pandemics of modern times, having already caused 35 million deaths around the world. Despite the huge efforts spent to develop treatments, the virus cannot yet be eradicated and continues to infect new people. Spread of the virus remains uncontrolled, thus exposing the worldwide population to HIV danger, due to the lack of efficient vaccines. The latest clinical trials describe the challenges associated with developing an effective prophylactic HIV vaccine. These immunological obstacles will only be overcome by smart and innovative solutions applied to the design of vaccine formulations. Here, we describe the use of nanostructured lipid carriers (NLC) for the delivery of p24 protein as a model HIV antigen, with the aim of increasing its immunogenicity. We have designed vaccine formulations comprising NLC grafted with p24 antigen, together with cationic NLC optimized for the delivery of immunostimulant CpG. This tailored system significantly enhanced immune responses against p24, in terms of specific antibody production and T-cell activation in mice. More importantly, the capacity of NLC to induce specific immune responses against this troublesome HIV antigen was further supported by a 7-month study on non-human primates (NHP). This work paves the way toward the development of a future HIV vaccine, which will also require the use of envelope antigens.

Setting Precise Temperature for Triggered Release from Nanostructured Lipid Carriers

Abstract The preparation and use of nanostructured lipid carriers (NLCs) as drug delivery system is constantly growing. NLCs are prepared from synthetic or natural lipids with known, but not controlled, melting point. Here we propose the preparation of NLCs combining natural lipids to have selected melting temperature. Vegetable butters were subjected to gas chromatography to determine and define each constituent and melting point. Three different NLCs suspensions were prepared from a specific blend of vegetable butters, adjusted to start melting at 29, 37 or 42°C, and characterized. Precise engineering of the delivery system will contribute to efficient temperature triggered release.

Interactions of the antimicrobial peptide nisin Z with conventional antibiotics and the use of nanostructured lipid carriers to enhance antimicrobial activity

Antimicrobial resistance is an imminent threat to the effective prevention and treatment of bacterial infections and alternative antimicrobial strategies are desperately needed. Antimicrobial peptides (AMPs) may be promising alternatives to current antibiotics or act as adjuvants to enhance antibiotic potency. Additionally, the use of biodegradable lipid nanoparticles can enhance the antibacterial activity of antibiotics and antimicrobial peptides. In this study, the interaction of the AMPs, nisin Z and melittin, with conventional antibiotics was investigated on Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli. The effectiveness of nanostructured lipid carriers (NLCs) for the entrapment of nisin Z was also evaluated. Findings revealed that nisin Z exhibited additive interactions with numerous conventional antibiotics. Notable synergism was observed for novobiocin-nisin Z combinations. The addition of the non-antibiotic adjuvant EDTA significantly improved the antimicrobial activity of free nisin Z towards E.coli. NLCs containing nisin Z were effective against Gram-positive species at physiological pH, with an increase in effectiveness in the presence of EDTA. Results indicate that nisin Z may be advantageous as an adjuvant in antimicrobial chemotherapy, while contributing in the battle against antibiotic resistance. NLCs have the potential to enhance the antibacterial activity of nisin Z towards Gram-positive bacterial species associated with skin infections.

Biocompatible Lipid Nanoparticles as Carriers To Improve Curcumin Efficacy in Ovarian Cancer Treatment.

Curcumin is a natural molecule with proved anticancer efficacy on several human cancer cell lines. However, its clinical application has been limited due to its poor bioavailability. Nanocarrier-based drug delivery approaches could make curcumin dispersible in aqueous media, thus overtaking the limits of its low solubility. The aim of this study was to increase the bioavailability and the antitumoral activity of curcumin, by entrapping it into nanostructured lipid carriers (NLCs). For this purpose here we describe the preparation and characterization of three kinds of curcumin-loaded NLCs. The nanosystems allowed the achievement of a controlled release of curcumin, the amounts of curcumin released after 24 h from Compritol-Captex, Compritol-Miglyol, and Compritol NLCs being, respectively, equal to 33, 28, and 18% w/w on the total entrapped curcumin. Considering the slower curcumin release profile, Compritol NLCs were chosen to perform successive in vitro studies on ovarian cancer cell lines. The results show that curcumin-loaded NLCs maintain anticancer activity, and reduce cell colony survival more effectively than free curcumin. As an example, the ability of A2780S cells to form colonies was decreased after treatment with 5 μM free curcumin by 50% ± 6, whereas, at the same concentration, the delivery of curcumin with NLC significantly (p < 0.05) inhibited colony formation to approximately 88% ± 1, therefore potentiating the activity of curcumin to inhibit A2780S cell growth. The obtained results clearly suggest that the entrapment of curcumin into NLCs increases curcumin efficacy in vitro, indicating the potential use of NLCs as curcumin delivery systems.

Co-encapsulating nanostructured lipid carriers for transdermal application: From experimental design to the molecular detail

Co-encapsulation of drugs directed at commonly associated diseases provides a convenient means for administration, especially if transdermally delivered.In this work, a comprehensive study for the co-encapsulation of drugs with a differential lipophilicity, olanzapine and simvastatin, and their transdermal delivery in a formulation containing nanostructured lipid carriers (NLC) is presented. Focus is given to the evaluation of a strategy in which NLC and chemical permeation enhancers are combined. It comprises in vitro, in silico and cellular viability approaches. The optimization and rationalization of the systems are carried out using a two-step factorial design. It is shown that the external medium in the NLC dispersion strongly influences permeation. It is also seen that the use of NLC determines a synergistic effect with selected permeation enhancers, thus promoting marked flux enhancement ratios (48 and 21, respectively for olanzapine and simvastatin) relative to the drugs in solution. The developed formulations can be considered non-irritant. A correlation between enhancer positioning in a lipid bilayer, partially governed by a H-bonding phenomenon, and enhancement effect is suggested from molecular dynamics studies and experimental observations.

Potential Use of Nanostructured Lipid Carriers for Topical Delivery of Flurbiprofen

The potential use of nanostructured lipid carriers (NLC) composed of a fatty acid [stearic acid (SA)] or a triglyceride (glyceryl behenate) as solid lipids, and a mixture of medium chain triglycerides and castor oil as liquid lipids, for skin administration of flurbiprofen (FB), has been explored. Two different optimized NLC formulations (FB-SANLC based on SA vs. FB-C888NLC based on glyceryl behenate), with respect to the morphometrical properties (particle size and polydispersity index) and the entrapment efficiency, were used in this study. The ex vivo permeation profiles of FB-C888NLC, FB-SANLC and conventional FB solution were evaluated using human skin. An improved FB permeation was observed when the drug was delivered by skin application of FB-C888NLC, attributed to the particle size and matrix crystallinity. The differential scanning calorimetry and X-ray diffraction studies suggested major polymorphic transitions in the lipid matrix of FB-C888NLC. A good correlation between polymorphic transitions and increased drug permeation was observed. However, both NLC dispersions showed a penetration-enhancing ratio (ER) higher than conventional FB solution. The in vitro and in vivo irritancy and local tolerability were assessed by running, respectively, the SKINTEX™ and Draize test. Both FB-C888NLC and FB-SANLC were classified as nonirritant.