Nanostructured lipid carriers and their current application in targeted drug delivery

Preparation, Pharmacokinetics, and Antitumor Potential of Miltefosine-Loaded Nanostructured Lipid Carriers

BACKGROUND

The purpose of this study was to investigate the suitability of nanostructured lipid carriers (NLCs) loaded with miltefosine (HePC) as an anticancer drug for the treatment of breast cancer.

METHODS

HePC-NLCs were prepared using a microemulsion technique and then evaluated for particle size, polydispersity index (PDI), incorporation efficiency, in vitro release of entrapped drug, and hemolytic potential. Furthermore, pharmacokinetic, biodistribution, and liver toxicity analyses were performed in Sprague-Dawley rats, and antitumor efficacy was evaluated in Michigan Cancer Foundation-7 (MCF-7) and squamous cell carcinoma-7 (SCC-7) cells in vitro and in tumour-bearing BALB/c mice in vivo. Advanced analyses including survival rate, immunohistopathology, and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assays were performed to evaluate apoptosis in vivo.

RESULTS

The average particle size of the HePC-NLCs was 143 ± 16 nm, with a narrow PDI (0.104 ± 0.002), and the incorporation efficiency was found to be 91 ± 7%. The NLCs released HePC in a sustained manner, and this release was significantly lower than that of free drug. The in vitro hemolytic assay demonstrated a significantly reduced hemolytic potential (~9%) of the NLCs compared to that of the test formulations. The HePC-NLCs demonstrated enhanced pharmacokinetic behaviour over free drug, including extended blood circulation and an abridged clearance rate in rats. Furthermore, the HePC-NLCs exhibited higher cytotoxicity than the free drug in MCF-7 and SCC-7 cells. Moreover, the HePC-NLCs showed significantly enhanced (P < 0.005) antitumor activity compared to that of the control and free drug-treated mouse groups. Tumour cell apoptosis was also confirmed, indicating the antitumor potential of the HePC-NLCs.

CONCLUSION

These findings demonstrate the ability of NLCs as a drug delivery system for enhanced pharmacokinetic, antitumor, and apoptotic effects, most importantly when loaded with HePC.

Preparation of magnetic nanoparticle integrated nanostructured lipid carriers for controlled delivery of ascorbyl palmitate

Most cancer treatments can cause vital side effects on healthy tissues. Ascorbic acid (AA) is a water-soluble antioxidant molecule and possesses a variety of functions such as prevention of tumor proliferation and treatment of cancer. However, AA, is very sensitive to air, heat and light. Its high hydrophilicity also makes the controlled delivery difficult. To overcome these problems, AA can be chemically-modified and made more hydrophobic by the esterification. Palmitic acid is one of the most common long-chain fatty acids that can be used for this purpose. It is known that Ascorbyl palmitate (AP) which is a lipopihilic derivative of AA, can inhibit cell proliferation and DNA synthesis in many types of cancer. Although AP has higher stability, its bioavailability and therapeutic effect is low due to its lipophilicity and low release capacity.•

In this study, nanostructured lipid carriers (NLC) which are colloidal nanoparticles with high biocompatibility, low crystallinity and high hydrophobic-drug encapsulation capacity was prepared to increase the bioavailability of AP.

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To provide triggered drug release via hyperthermia, magnetic nanoparticles (MNps) were integrated into the NLCs besides AP.

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The synthesis of biocompatible NLCs with controlled and triggered release ability, is successfully completed and controlled release of AP as an antitumor agent is achieved.

Injectable Thermosensitive Hydrogel Containing Erlotinib-Loaded Hollow Mesoporous Silica Nanoparticles as a Localized Drug Delivery System for NSCLC Therapy

Erlotinib (ERT), oral administration agents, is one of the most pivotal targeted drugs in the treatment of non-small cell lung cancer (NSCLC); however, its poor solubility, low oral bioavailability, and capricious toxicity limit broader clinical applications. In this paper, a novel injectable matrix is prepared based on hollow mesoporous silica nanoparticles (HMSNs) and thermosensitive poly(d,l-lactide)-poly(ethylene glycol)-poly(d,l-lactide) (PDLLA-PEG-PDLLA, PLEL) hydrogel to encapsulate and localize the sustained release of ERT for improved efficacy against NSCLC. The test-tube-inversion method shows that this ERT-loaded hydrogel composite (ERT@HMSNs/gel) presents as an injectable flowing solution under room temperature and transfers into a physically crosslinked non-flowing gel structure at physiological temperature.The ERT@HMSNs/gel composite shows a much longer intratumoral and peritumoral drug retention by in vivo imaging study. Notably, this injectable drug delivery system (DDS) provides an impressive balance between antitumor efficacy and systemic safety in a mice xenograft model. The novel ERT loaded HMSNs/gel system may be a promising candidate for the in situ treatment of NSCLC. Moreover, this study provides a prospective platform for the design and fabrication of a nano-scaled delivery system for localized anticancer therapies.

Nanotechnology to improve the Alzheimer's disease therapy with natural compounds

Alzheimer's disease (AD) is a form of dementia with high impact worldwide, accounting with more than 46 million cases. It is estimated that the number of patients will be four times higher in 2050. The initial symptoms of AD are almost imperceptible and typically involve lapses of memory in recent events. However, the available medicines still focus on controlling the symptoms and do not cure the disease. Regarding the advances in the discovery of new treatments for this devastating disease, natural compounds are gaining increasing relevance in the treatment of AD. Nevertheless, they present some limiting characteristics such as the low bioavailability and the low ability to cross the blood-brain barrier (BBB) that hinder the development of effective therapies. To overcome these issues, the delivery of natural products by targeting nanocarriers has aroused a great interest, improving the therapeutic activity of these molecules. In this article, a review of the research progress on drug delivery systems (DDS) to improve the therapeutic activity of natural compounds with neuroprotective effects for AD is presented. Graphical abstract.

Nanotechnological strategies for systemic microbial infections treatment: A review

Systemic infections is one of the major causes of mortality worldwide, and a shortage of drug approaches applied for the rapid and necessary treatment contribute to increase the levels of death in affected patients. Several drug delivery systems based in nanotechnology such as metallic nanoparticles, liposomes, nanoemulsion, microemulsion, polymeric nanoparticles, solid lipid nanoparticles, dendrimers, hydrogels and liquid crystals can contribute in the biological performance of active substances for the treatment of microbial diseases triggered by fungi, bacteria, virus and parasites. In the presentation of these statements, this review article present and demonstrate the effectiveness of these drug delivery systems for the treatment of systemic diseases caused by several microorganisms, through a review of studies on scientific literature worldwide that contributes to better information for the most diverse professionals from the areas of health sciences. The studies demonstrated that the drug delivery systems described can contribute to the therapeutic scenario of these diseases, being classified as safe, active platforms and with therapeutic versatility.

Exploiting solid lipid nanoparticles and nanostructured lipid carriers for drug delivery against cutaneous fungal infections

Several types of cutaneous fungal infections can affect the population worldwide, such as dermatophytosis, cutaneous candidiasis, onychomycosis, and sporotrichosis. However, oral treatments have pronounced adverse effects, making the topical route an alternative to avoid this disadvantage. On the other hand, currently available pharmaceutical forms designed for topical application, such as gels and creams, do not demonstrate effective retention of biomolecules in the upper layers of the skin. An interesting approach to optimise biomolecules' activity in the skin is the use of nanosystems for drug delivery, especially solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC), which in the past decade has shown advantages like increased adhesiveness, great occlusive properties and higher biomolecule deposition in stratum corneum when designed for topical application. Considering the demand for more effective therapeutic alternatives and the promising characteristics of SLN and NLC for topical application, the present study sought to gather studies that investigated the potential of using SLN and NLC for the treatment of cutaneous fungal infections. Studies demonstrated that these nanosystems showed optimisation, mostly, of the effectiveness of biomolecules besides other biopharmaceutical properties, in addition to offering potential occlusion and hydration of the applied region.

Lipid-based Nanoplatforms in Cancer Therapy: Recent Advances and Applications

Though modern available cancer therapies are effective, they possess major adverse effects, causing non-compliance to patients. Furthermore, the majority of the polymeric-based medication platforms are certainly not universally acceptable, due to their several restrictions. With this juxtaposition, lipid-based medication delivery systems have appeared as promising drug nanocarriers to replace the majority of the polymer-based products because they are in a position to reverse polymer as well as, drug-associated restrictions. Furthermore, the amalgamation of the basic principle of nanotechnology in designing lipid nanocarriers, which are the latest form of lipid carriers, has tremendous chemotherapeutic possibilities as tumor-targeted drug-delivery pertaining to tumor therapy. Apart from this, it is reported that nearly 40% of the modern medication entities are lipophilic. Moreover, research continues to be efficient in attaining a significant understanding of the absorption and bioavailability of the developed lipids systems.

Polymeric Nanoscale Drug Carriers Mediate the Delivery of Methotrexate for Developing Therapeutic Interventions Against Cancer and Rheumatoid Arthritis

Methotrexate (MTX) is widely used as an anticancer and anti-inflammtory drug for treating various types of cancer and autoimmune diseases. The optimal dose of MTX is known to inhibit the dihydrofolatereductase that hinders the replication of purines. The nanobiomedicine has been extensively explored in the past decade to develop myriad functional nanostructures to facilitate the delivery of therapeutic agents for various medical applications. This review is focused on understanding the design and development of MTX-loaded nanoparticles alongside the inclusion of recent findings for the treatment of cancers. In this paper, we have made a coordinated effort to show the potential of novel drug delivery systems by achieving effective and target-specific delivery of methotrexate.

The preparation of lipid-based drug delivery system using melt extrusion

Melt extrusion of lipids is versatile with high applicability in the pharmaceutical industry. The formulations prepared can be easily customized depending on the requirements, and have the potential to open a window on personalized medicine.

Lipid Drug Carriers for Cancer Therapeutics: An Insight into Lymphatic Targeting, P-gp, CYP3A4 Modulation and Bioavailability Enhancement

In the treatment of cancer, chemotherapy plays an important role though the efficacy of anti-cancer drug administered orally is limited, due to their poor solubility in physiological medium, inability to cross biological membrane, high Para-glycoprotein (P-gp) mediated drug efflux, and pre-systemic metabolism. These all factors cumulatively reduce drug exposure at the target site leading to multidrug resistance (MDR). Lipid based carriers systems has been explored to overcome solubility and permeability related issues of anti-cancer drugs. The lipid based formulations have also been reported to circumvent the effect of P-gp and CYP3A4. Further long chain triglycerides (LCT) has shown their ability to access Lymphatic route over Medium Chain Triglycerides, as the former has been extensively used for targeting anti-cancer drugs at proliferating cells through lymphatic route. Therefore this review tries to reflect the usefulness of lipid based drug carriers systems (viz. liposome, solid lipid nanoparticle, nano-lipid carriers, self-emulsifying, lipidic pro-drugs) in targeting lymphatic system and overcoming issues related to solubility and permeability of anti-cancer drugs. Moreover, we have also tried to reflect how critically lipid based carriers are important in maximizing therapeutic safety and efficacy of anti-cancer drugs.

Nanocarriers for ocular drug delivery: current status and translational opportunity

Ocular diseases have a significant effect on vision and quality of life. Drug delivery to ocular tissues is a challenge to formulation scientists. The major barriers to delivering drugs to the anterior and posterior segments include physiological barriers (nasolacrimal drainage, blinking), anatomical barriers (static and dynamic), efflux pumps and metabolic barriers. The static barriers comprise the different layers of the cornea, sclera, and blood-aqueous barriers whereas dynamic barriers involve conjunctival blood flow, lymphatic clearance and tear drainage. The tight junctions of the blood-retinal barrier (BRB) restrict systemically administered drugs from entering the retina. Nanocarriers have been found to be effective at overcoming the issues associated with conventional ophthalmic dosage forms. Various nanocarriers, including nanodispersion systems, nanomicelles, lipidic nanocarriers, polymeric nanoparticles, liposomes, niosomes, and dendrimers, have been investigated for improved permeation and effective targeted drug delivery to various ophthalmic sites. In this review, various nanomedicines and their application for ophthalmic delivery of therapeutics are discussed. Additionally, scale-up and clinical status are also addressed to understand the current scenario for ophthalmic drug delivery.

Advances in drug delivery systems: Work in progress still needed?

A new era of science and technology has emerged in pharmaceutical research with focus on developing novel drug delivery systems for oral administration. Conventional dosage forms like tablets and capsules are associated with a low bioavailability, frequent application, side effects and hence patient noncompliance. By developing novel strategies for drug delivery, researchers embraced an alternative to traditional drug delivery systems. Out of those, fast dissolving drug delivery systems are very eminent among pediatrics and geriatrics. Orally disintegrating films are superior over fast dissolving tablets as the latter are assigned with the risk of suffocation. Due to their ability of bypassing the dissolution and the first pass effect after oral administration, self-emulsifying formulations have also become increasingly popular in improving oral bioavailability of hydrophobic drugs. Osmotic devices enable a controlled drug delivery independent upon gastrointestinal conditions using osmosis as driving force. The advances in nanotechnology and the variety of possible materials and formulation factors enable a targeted delivery and triggered release. Vesicular systems can be easily modified as required and provide a controlled and sustained drug delivery to a specific site.

This work provides an insight of the novel approaches in drug delivery covering the critical comparison between traditional and novel “advanced-designed” systems.

Self-assembled polydopamine nanoparticles improve treatment in Parkinson's disease model mice and suppress dopamine-induced dyskinesia

Although Levodopa (l-DOPA), a dopamine precursor, exhibits a high risk of dyskinesia, it remains the primary treatment in Parkinson's disease (PD), a progressive neurodegenerative disorder. In this study, we designed poly(l-DOPA)-based self-assembled nanodrug (Nano^DOPA) from amphiphilic block copolymer possessing poly(l-DOPA(OAc)₂), which is a precursor of l-DOPA as a hydrophobic segment, for treatment in a PD model mouse. Under physiological enzyme treatment, the poly(l-DOPA(OAc)₂) in the block copolymer was hydrolyzed to liberate l-DOPA gradually. Using the MPTP-induced PD mouse model, we observed that mice treated with Nano^DOPA demonstrated a significant improvement of PD symptoms compared to the l-DOPA treatment. Interestingly, the Nano^DOPA treatment did not cause the dyskinesia symptoms, which was clearly observed in the l-DOPA-treated mice. Furthermore, Nano^DOPA exhibited remarkably lower toxicity in vitro compared to l-DOPA, in addition with no noticeable Nano^DOPA toxicity observed in the treated mice. These results suggested that self-assembled Nano^DOPA is a promising therapeutic in the treatment of PD. STATEMENT OF SIGNIFICANCE: In this study, we proposed a therapeutic approach for the effective treatment of Parkinson's disease (PD) using newly designed poly(l-DOPA)-based self-assembled nanodrug (Nano^DOPA) prepared from amphiphilic block copolymers possessing poly(l-DOPA(OAc)₂), which is a precursor of l-DOPA as a hydrophobic segment, for treatment in a PD model mouse. Under physiological enzyme treatments, Nano^DOPA was hydrolyzed to liberate l-DOPA gradually, improving the pharmacokinetic value of l-DOPA. The mice treated with Nano^DOPA significantly improved PD symptoms compared to the l-DOPA treatment in a neurotoxin-induced PD mouse model. Interestingly, Nano^DOPA treatment did not cause dyskinesia symptoms, which was observed in the l-DOPA-treated mice. The obtained results in this study suggested that self-assembled Nano^DOPA is a promising therapeutic in the treatment of PD.

Co-delivery of rituximab targeted curcumin and imatinib nanostructured lipid carriers in non-Hodgkin lymphoma cells

The aim of the present study was production of nanostructured lipid carriers (NLCs) of curcumin and imatinib for co-administration in non-Hodgkin lymphoma cells. NLCs were prepared and conjugated to rituximab to target CD20 receptors of lymphoma cell lines. Oleic acid or Labrafac and glyceryl monostearate or lecithin were used for production of NLCs. The antibody coupling efficiency to NLCs and their physical characteristics were studied. The cytotoxicity of NLCs on Jurkat T cells (CD20 receptor negative) and Ramos B cells (CD20 receptor positive) was studied by MTT assay. The cellular uptake was determined by fluorescent microscopy. The results indicated both curcumin and imatinib targeted NLCs had a significant cytotoxic effect much higher than the free drugs and non-targeted NLCs on Ramos cells. In both cell lines, the cytotoxicity of the co-administrated drugs was significantly higher than each drug alone. In Ramos cells the co-administration of curcumin (15 μg/ml)/imatinib (5 μg/ml) decreased the free curcumin IC₅₀ from 8.3 ± 0.9 to 1.9 ± 0.2 μg/ml, and curcumin targeted NLCs from 6.7 ± 0.1 to 1.3 ± 0.2 μg/ml. In this case the IC₅₀ of imatinib was reduced from 11.1 ± 0.7 to 2.3 ± 0.1 μg/ml and imatinib targeted NLCs from 4.3 ± 0.1 to 1.4 ± 0.0 μg/ml. The co-administration of ritoximab conjugated NLCs of curcumin and imatinib may enhance cytotoxicity of imatinib in treatment of non-Hodgkin lymphoma.

Nanostructured Lipid Carriers: A Groundbreaking Approach for Transdermal Drug Delivery

Nanostructured lipid carriers (NLCs) are novel pharmaceutical formulations which are composed of physiological and biocompatible lipids, surfactants and co-surfactants. Over time, as a second generation lipid nanocarrier NLC has emerged as an alternative to first generation nanoparticles. This review article highlights the structure, composition, various formulation methodologies, and characterization of NLCs which are prerequisites in formulating a stable drug delivery system. NLCs hold an eminent potential in pharmaceuticals and cosmetics market because of extensive beneficial effects like skin hydration, occlusion, enhanced bioavailability, and skin targeting. This article aims to evoke an interest in the current state of art NLC by discussing their promising assistance in topical drug delivery system. The key attributes of NLC that make them a promising drug delivery system are ease of preparation, biocompatibility, the feasibility of scale up, non-toxicity, improved drug loading, and stability.

SLN and NLC for topical, dermal, and transdermal drug delivery

Introduction: From a biopharmaceutical standpoint, the skin is recognized as an interesting route for drug delivery. In general, small molecules are able to penetrate the stratum corneum, the outermost layer of the skin. In contrast, the delivery of larger molecules, such as peptides and proteins, remains a challenge. Nanoparticles have been exploited not only to enhance skin penetration of drugs but also to expand the range of molecules to be clinically used.Areas covered: This review focus on Solid lipid nanoparticles (SLN) and Nanostructured lipid carriers (NLC) for skin administration. We discuss the selection criteria for lipids, surfactants, and surface modifiers commonly in use in SLN/NLC, their production techniques, and the range of drugs loaded in these lipid nanoparticles for the treatment of skin disorders.Expert opinion: Depending on the lipid and surfactant composition, different nanoparticle morphologies can be generated. Both SLN and NLC are composed of lipids that resemble those of the skin and sebum, which contribute to their enhanced biocompatibility, with limited toxicological risk. SLN and NLC can be loaded with very chemically different drugs, may provide a tunable release profile, can be produced in a sterilized environment, and be scaled-up without the need for organic solvents.

Vitamin D microencapsulation and fortification: Trends and technologies

Today, as per the latest medical reports available, majority of the population throughout globe is facing vitamin D (Vit D) deficiency. Even in sub-tropical countries like India and many others Vit D deficiency is highly prevalent despite the exuberant available sunshine (a major source of Vit D) throughtout the year. The reason could be attributed to an array of factors including socioeconomical, cultural and religious. Further, other than the sunlight, there are very limited sources of Vit D to fulfil the recommended dietary allowance of Vit D (RDA: 400-800 IU per day). A large proportion of Vit D is lost during food processing and storage due to environmental stress conditions such as temperature, pH, salt, oxygen and light. Vita D, an important micronutrient, is essentially required for the prevention of disorders such as neurodegenerative diseases, cardiovascular diseases, cancer etc. in addition to its traditional role in bone metabolism. Therefore, in order to meet the daily requirements of Vit D for human body, WHO has recognized fortification as the most efficient and safest method to address malnutrition. But there are innumerable chellenges involved during food fortification using Vit D as fortificants such as homogeneity into the food matrix, physico-chemical/photochemical degradation, loss during processing and storage, interactions with other components of food matrix resulting into change in taste, texture and appearance thus affecting acceptability, palatability and marketability. Fortification of Vit D into food products especially the ones which have an aqueous portion, is not simple for food technologist. Recent advances in nanotechnology offer various microencapsulation techniques such as liposome, solid-lipid particles, nanostructured lipid carriers, emulsion, spray drying etc. which have been used to design efficient nanomaterials with desired functionality and have great potential for fortification of fortificants like Vit D. The present review is an undate on Vit D, in light of its fortification level, RDA, factors affecting its bioavailability and various microencapsulation techniques adopted to develop Vit D-nanomaterials and their fate in food fortification.

Lipid-based nanoformulations in the treatment of neurological disorders

The neurological disorders affect millions of people worldwide, and are bracketed as the foremost basis of disability-adjusted life years (DALYs). The treatment options are symptomatic and often the movement of drugs is restricted by a specialized network of endothelial cell layers (adjoined by tight cell-to-cell junction proteins; occludin, claudins, and junctional adhesion molecules), pericytes and astroglial foot processes. In recent years, advances in nanomedicine have led to therapies that target central nervous system (CNS) pathobiology via altering signaling mechanisms such as activation of PI3K/Akt pathway in ischemic stroke arrests apoptosis, interruption of α-synuclein aggregation prevents neuronal degeneration in Parkinson's. Often such interactions are limited by insufficient concentrations of drugs reaching neuronal tissues and/or insufficient residence time of drug/s with the receptor. Hence, lipid nanoformulations, SLNs (solid lipid nanoparticles) and NLCs (nanostructured lipid carriers) emerged to overcome these challenges by utilizing physiological transport mechanisms across blood-brain barrier, such as drug-loaded SLN/NLCs adsorb apolipoproteins from the systemic circulation and are taken up by endothelial cells via low-density lipoprotein (LDL)-receptor mediated endocytosis and subsequently unload drugs at target site (neuronal tissue), which imparts selectivity, target ability, and reduction in toxicity. This paper reviews the utilization of SLN/NLCs as carriers for targeted delivery of novel CNS drugs to improve the clinical course of neurological disorders, placing some additional discussion on the metabolism of lipid-based formulations.

Multifunctional Nanocarriers for Lung Drug Delivery

Nanocarriers have been increasingly proposed for lung drug delivery applications. The strategy of combining the intrinsic and more general advantages of the nanostructures with specificities that improve the therapeutic outcomes of particular clinical situations is frequent. These include the surface engineering of the carriers by means of altering the material structure (i.e., chemical modifications), the addition of specific ligands so that predefined targets are reached, or even the tuning of the carrier properties to respond to specific stimuli. The devised strategies are mainly directed at three distinct areas of lung drug delivery, encompassing the delivery of proteins and protein-based materials, either for local or systemic application, the delivery of antibiotics, and the delivery of anticancer drugs-the latter two comprising local delivery approaches. This review addresses the applications of nanocarriers aimed at lung drug delivery of active biological and pharmaceutical ingredients, focusing with particular interest on nanocarriers that exhibit multifunctional properties. A final section addresses the expectations regarding the future use of nanocarriers in the area.

Percutaneous Delivery of Antihypertensive Agents: Advances and Challenges

Hypertension remains a significant risk factor for several cardiovascular disorders including coronary artery disease and heart failure. Despite the large armamentarium of drugs available for the management of high blood pressure, low oral availability is an ongoing challenge. Researchers are constantly developing alternative drug delivery systems. This review focuses on the transcutaneous delivery of antihypertensive agents. The use of diverse technologies for the delivery of specific antihypertensive agents is emphasized. The advances made and the challenges encountered are highlighted. Several transdermal drug delivery strategies are employed for the transport of this group of therapeutic agents across the skin and the most widely used techniques include microneedles, iontophoresis, sonophoresis, and chemical penetration enhancers. Each of these methods has benefits and limitations, and there are ongoing attempts by scientists to address the shortcomings. For instance, skin irritation continues to be a major challenge with iontophoretic transport while the quantity of a medication that can be incorporated into dissolving microneedles is limited. With skin permeation enhancers, concerns relating to cytotoxicity and irritation are common. Even though the use of ultrasound is exciting, this mode of delivery is also accompanied by challenges such as the design of a battery system that is potent enough to drive a low-frequency sonophoretic cymbal array, while still being portable enough to function as a wearable device. Although most researchers report enhanced drug delivery with the aforementioned methods, it is important to deliver therapeutically useful doses of these medications.

Emerging Complexity and the Need for Advanced Drug Delivery in Targeting Candida Species

Background:

Candida species are the important etiologic agents for candidiasis, the most prevalent cause of opportunistic fungal infections. Candida invasion results in mucosal to systemic infections through immune dysfunction and helps in further invasion and proliferation at several sites in the host. The host defence system utilizes a wide array of the cells, proteins and chemical signals that are distributed in blood and tissues which further constitute the innate and adaptive immune system. The lack of antifungal agents and their limited therapeutic effects have led to high mortality and morbidity related to such infections.

Methods:

The necessary information collated on this review has been gathered from various literature published from 1995 to 2019.

Results:

This article sheds light on novel drug delivery approaches to target the immunological axis for several Candida species (C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, C. rugose, C. hemulonii, etc.).

Conclusion:

It is clear that the novel drug delivery approaches include vaccines, adoptive transfer of primed immune cells, recombinant cytokines, therapeutic antibodies, and nanoparticles, which have immunomodulatory effects. Such advancements in targeting various underpinning mechanisms using the concept of novel drug delivery will provide a new dimension to the fungal infection clinic particularly due to Candida species with improved patient compliance and lesser side effects. This advancement in knowledge can also be extended to target various other similar microbial species and infections.

Ultrasound-assisted preparation of different nanocarriers loaded with food bioactive ingredients

Developing green and facile approaches to produce nanostructures suitable for bioactives, nanoencapsulation faces some challenges in the nutraceutical and food bioactive industries due to potential risks arising from nanomaterials fabrication and consumption. High-intensity ultrasound is an effective technology to generate different bio-based structures in sub-micron or nanometer scale. This technique owing to some intrinsic advantages such as safety, straightforward operation, energy efficiency, and scale-up potential, as well as, ability to control over size and morpHology has stood out among various nanosynthetic routes. Ultrasonically-provided energy is mainly transferred to the droplets and particles via acoustic cavitation (which is formation, growth, and implosive collapse of bubbles in solvent). This review provides an outlook on the fundamentals of ultrasonication and some applicable setups in nanoencapsulation. Different kinds of nanostructures based on surfactants, lipids, proteins and carbohydrates formed by sonication, along with their advantages and disadvantages are assessed from the viewpoint of stability, particle size, and process impacts on some functionalities. The gastrointestinal fate and safety issues of ultrasonically prepared nanostructures are also discussed. Sonication, itself or in combination with other encapsulation approaches, alongside biopolymers generate nano-engineered carriers with enough stability, small particle sizes, and a low polydispersity. The nano-sized systems improve techno-functional activities of encapsulated bioactive agents including stability, solubility, dissolution, availability, controlled and targeted release profile in vitro and in vivo plus other bioactive properties such as antioxidant and antimicrobial capacities. Ultrasonically prepared nanocarriers show a great potential in fortifying food products with desired bioactive components, especially for the industrial applications.

Dithranol-loaded nanostructured lipid carrier-based gel ameliorate psoriasis in imiquimod-induced mice psoriatic plaque model

OBJECTIVE

The aim of this study was to formulate nanostructured lipid carriers (NLCs) of dithranol-loaded in gel for ease of application and to evaluate its anti-psoriatic efficacy vis-a-vis conventional ointment formulation.

SIGNIFICANCE

This study will provide an insight about the use of nanocarriers, esp. NLCs loaded with dithranol for the effective treatment of psoriasis.

METHODS

Dithranol-loaded NLCs were prepared by hot melt homogenization method and characterized for particle size and percentage entrapment efficiency. The optimized NLCs were loaded into gel and evaluated for drug release, spreadability, rheological behavior, and staining. Anti-psoriatic efficacy of the NLC gel was evaluated in imiquimod (IMQ) induced psoriatic plaque model in comparison with prepared conventional ointment formulation (1.15% w/w dithranol).

RESULTS

NLCs were prepared with particle size below 300 nm, polydispersity index (PDI) below 0.3 and percentage entrapment efficiency of ∼100%. The prepared NLC gel was then compared with the ointment for drug release, staining property, and efficacy. Topical application of dithranol-loaded NLC gel on IMQ-induced psoriatic plaque model reduced the symptoms of psoriasis assessed by both Psoriasis area severity index (PASI) scoring and enzyme-linked immunosorbent assay. There was a significant reduction in disease severity and cytokines like Interleukins-17, 22, 23 and Tumor necrosis factor-α by the developed system in comparison to the negative control.

CONCLUSIONS

To conclude dithranol-loaded NLCs in gel base was efficacious in management of psoriasis at the same drug concentration and also offer less cloth staining to that of the ointment product.

Active Targeting of Drugs and Bioactive Molecules via Oral Administration by Ligand-Conjugated Lipidic Nanocarriers: Recent Advances

The oral route is the most widely accepted and commonly used route for administration. However, this route may not be suitable for certain drug candidates which suffer from the problem of low aqueous solubility and gastrointestinal absorption and extensive first-pass effect. Nanotechnology-based approaches can be taken up as remedies to overcome the disadvantages associated with the oral route. Among the various nanocarriers, lipidic nanocarriers are widely used for oral delivery of bioactive molecules owing to their several advantages. Active targeting of bioactive molecules via lipidic nanocarriers has also been widely attempted to improve oral bioavailability and to avoid first-pass effect. This active targeting approach involves the use of ligands grafted or conjugated onto a nanocarrier that is specific to the receptors. Active targeting increases the therapeutic efficacy as well as reduces the toxic side effects of the drug or bioactive molecules. This review mainly focuses on the challenges involved in the oral delivery of drugs and its approaches to overcome the challenges using nanotechnology, specifically focusing on lipidic nanocarriers like liposomes, solid lipid nanoparticles, and nanostructured lipid carriers and active targeting of drug molecules by making use of ligand-conjugated lipidic nanocarriers.

pH-sensitive PEGylation of RIPL peptide-conjugated nanostructured lipid carriers: design and in vitro evaluation

BACKGROUND

RIPL peptide (IPLVVPLRRRRRRRRC)-conjugated nanostructured lipid carriers (RIPL-NLCs) can facilitate selective drug delivery to hepsin (Hpn)-expressing cancer cells, but they exhibit low stability in the blood. Generally, biocompatible and nontoxic poly(ethylene glycol) surface modification (PEGylation) can enhance NLC stability, although this may impair drug delivery and NLC clearance. To attain RIPL-NLC steric stabilization without impairing function, pH-sensitive cleavable PEG (cPEG) was grafted onto RIPL-NLCs (cPEG-RIPL-NLCs).

METHODS

Various types of NLC formulations including RIPL-NLCs, PEG-RIPL-NLCs, and cPEG-RIPL-NLCs were prepared using the solvent emulsification-evaporation method and characterized for particle size, zeta potential (ZP), and cytotoxicity. The steric stabilization effect was evaluated by plasma protein adsorption and phagocytosis inhibition studies. pH-sensitive cleavage was investigated using the dialysis method under different pH conditions. Employing a fluorescent probe (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate [DiI]), in vitro drug delivery capacity of the cPEG-RIPL-NLCs under different pH conditions was also performed on Hpn-expressing SKOV3 cells and 3D-tumor spheroids.

RESULTS

All prepared NLCs showed homogenous dispersion (<220 nm in size) with a negative ZP (-18 to -22 mV), except for positively charged RIPL-NLCs (~10 mV), revealing no significant cytotoxicity in either SKOV3 or RAW 264.7 cell lines. cPEG-RIPL-NLC protein adsorption was 1.75-fold less than that of RIPL-NLCs, and PEGylation significantly reduced the macrophage uptake. PEG detachment from the cPEG-RIPL-NLCs was pH-sensitive and time dependent. At 2 hours incubation, cPEG-RIPL-NLCs and PEG-RIPL-NLCs exhibited comparable cellular uptake at pH 7.4, whereas cPEG-RIPL-NLC uptake was increased over 2-fold at pH 6.5. 3D-spheroid penetration also demonstrated pH-sensitivity: at pH 7.4, cPEG-RIPL-NLCs could not penetrate deep into the spheroid core region during 2 hours, whereas at pH 6.5, high fluorescence intensity in the core region was observed for both cPEG-RIPL-NLC-and RIPL-NLC-treated groups.

CONCLUSION

cPEG-RIPL-NLCs are good candidates for Hpn-selective drug targeting in conjunction with pH-responsive PEG cleavage.

Nanostructured lipid carriers: A potential use for skin drug delivery systems

Skin application of pharmaceutical products is one of the methods used for drug administration. The problem of limited drug penetration via topical application makes searching for safe drug carriers that will provide an expected therapeutic effect of utmost importance. Research into safe drug carriers began with liposome structures, paving the way for work with nanocarriers, which currently play a large role as drug vehicles. Nanostructured lipid carriers (NLC) consist of blended solid and liquid lipids (oils) dispersed in an aqueous solution containing a surfactant. These carriers have many advantages: good biocompatibility, low cytotoxicity, high drug content; they enhance a drug's stability and have many possibilities of application (oral, intravenous, pulmonary, ocular, dermal). The following article presents properties, methods of preparation and tests to assess the quality and toxicity of NLC. This analysis indicates the possibility of using NLC for dermal and transdermal drug application.

Application of nanoparticles in percutaneous delivery of active ingredients in cosmetic preparations

Developments in nanotechnology have expanded novel nanoparticles for several applications, including cosmetic topical preparation. The aim of this article was to review recent literature on percutaneous delivery of cosmetics active ingredient by nanoparticles. The main focus here, is on lipid based nanoparticles since they are of great importance in skin cargo delivery and have vast application in current cosmetic formulations. Data were collected via electronic databases using MeSH keywords, including nanoparticles, lipid particles, cosmetic, dermal delivery and combinations of these words. According to literature nanoparticles play a major role in improving the usefulness of cosmetics. They are able to improve the physiochemical stability of the skin based cosmetic products. Based on data, lipid nanostructures can be added to current cosmetic formulations without any significant problem due to their physical stability and compatibility with other ingredients. However, due to their basically risky nature of nanoparticles, their risk assessment should be taken into consideration.

Novel drug delivery systems for ocular therapy: With special reference to liposomal ocular delivery

Delivery of drugs to eyes is a great challenge to researchers because of a number of barriers in the eye preventing the actual dose from reaching the site. A number of ophthalmic delivery systems have been developed in the past couple of years that are not only new but also safe and reliable and help to overcome all those barriers in the eye which are responsible for the very less bioavailability of drugs. In this review, we tried to focus on current research in ocular delivery of drug substances giving special emphasis to liposomal delivery system. A brief analysis of other novel ocular delivery systems, ocular physiology, and microbial sources of disease are also highlighted herein. We analyzed the various research findings for churning a general idea for novel ocular delivery system and its future use. The novel formulations may overcome the addressed problems of ophthalmic medication and comply with the quality assurance issues. The liposomal delivery is advantageous as they have the ability to entrap both hydrophobic and hydrophilic drugs and are suitable for delivery to both the anterior and posterior segment of the eye. Therefore, the use of this alternative approach is quite a necessity.

Compound Stability in Nanoparticles: The Effect of Solid Phase Fraction on Diffusion of Degradation Agents into Nanostructured Lipid Carriers

The stability of active compounds encapsulated in nanoparticles depends on the resistance of the particles to diffusion of environmental degradation agents. In this paper, off-lattice Monte Carlo simulations are used to investigate a suspension of nanostructured lipid carriers (NLC) composed of interspaced liquid and solid lipid domains, immersed in a solution containing molecules representing oxidative or other degradation agents. The simulations examine the diffusion of the degradation agents into the nanoparticles as a function of nanoparticle size, solid domain fraction, and domain size. Two types of suspensions are studied: one (representing an infinitely dilute nanoparticle suspension) where the concentration of oxidative agents is constant in the solution around the particle and the other, finite system where diffusion into the nanoparticle causes depletion in the concentration of degradation agents in the surrounding solution. The total number of degradation agent molecules in the NLCs is found to decrease with the solid domain fraction, as may be expected. However, their concentration in the liquid domains is found to increase with the solid domain fraction. Since the degradation reaction depends on the concentration of the degradation agents, this suggests that compounds encapsulated in nanoparticles with high liquid content (such as emulsions) will degrade less and be more stable than those encapsulated in NLCs with high solid domain fraction, in agreement with previous experimental results.

Redox sensitive PEG controlled octaarginine and targeting peptide co-modified nanostructured lipid carriers for enhanced tumour penetrating and targeting in vitro and in vivo

To strengthen the anti-tumour efficacy and weaken the side effects, a nano targeted drug delivery system was constructed. The nanostructured lipid carriers (NLCs) were prepared by the melt-emulsification method. Modified with the octaarginine, thiolytic cleavable polyethylene glycol (PEG) and targeting peptide simultaneously on the surface, this multifunctional NLC could not only actively target to tumour tissues, but also control the cell penetration effect of the octaarginine easily by a safe reducing agent l-cysteine (l-Cys). In the present study, the pharmaceutical characteristics, the cytotoxicity and cellular uptake on NCI-H1299 cells in vitro, the biodistribution and targeting effect and anti-tumour ability in vivo were employed to evaluate the formulations. As the results revealed, various NLCs had a mean particle size of about 40 nm and a positive zeta potential of about 10 mV. The optimum density of cleavable PEG was confirmed as 10% and the best concentration of l-cysteine was determined as 20 mM via the qualitative and quantitative cellular uptake study. Based on these outcomes, the multiply decorated NLC manifested a great cell growth inhibition with the increased concentration of paclitaxel (PTX). Moreover, it preferred to accumulate at tumours, but not normal organs in vivo. Compared with Taxol^®, this preparation demonstrated stronger anti-tumour efficacy and better security. Therefore, the multifunctional NLC can be considered as a promising drug delivery system targeting to tumours.

Nanostructured lipid carriers of artemether-lumefantrine combination for intravenous therapy of cerebral malaria

Patients with cerebral malaria (CM) are unable to take oral medication due to impaired consciousness and vomiting thus necessitating parenteral therapy. Quinine, artemether, and artesunate which are currently used for parenteral malaria therapy have their own drawbacks. The World Health Organization (WHO) has now banned monotherapy and recommends artemisinin-based combination therapy for malaria treatment. However, presently there is no intravenous formulation available for combination therapy of malaria. Artemether-Lumefantrine (ARM-LFN) is a WHO approved combination for oral malaria therapy. However, the low aqueous solubility of ARM and LFN hinders their intravenous delivery. The objective of this study was to formulate ARM-LFN nanostructured lipid carriers (NLC) for intravenous therapy of CM. ARM-LFN NLC were prepared by microemulsion template technique and characterized for size, drug content, entrapment efficiency, drug release, crystallinity, morphology, amenability to autoclaving, compatibility with infusion fluids, stability, antimalarial efficacy in mice, and toxicity in rats. The ARM-LFN NLC showed sustained drug release, amenability to autoclaving, compatibility with infusion fluids, good stability, complete parasite clearance and reversal of CM symptoms with 100% survival in Plasmodium berghei-infected mice, and safety in rats. The biocompatible ARM-LFN NLC fabricated by an industrially feasible technique offer a promising solution for intravenous therapy of CM.