Itraconazole encapsulated PLGA-nanoparticles covered with mannose as potential candidates against leishmaniasis

Overview of Research on Leishmaniasis in Africa: Current Status, Diagnosis, Therapeutics, and Recent Advances Using By-Products of the Sargassaceae Family

Leishmaniasis in Africa, which has been designated as a priority neglected tropical disease by various global organizations, exerts its impact on millions of individuals, primarily concentrated within this particular region of the world. As a result of the progressively grave epidemiological data, numerous governmental sectors and civil organizations have concentrated their endeavors on this widespread outbreak with the objective of devising appropriate remedies. This comprehensive examination delves into multiple facets of this parasitic ailment, scrutinizing the associated perils, diagnostic intricacies, and deficiencies within the existing therapeutic protocols. Despite the established efficacy of current treatments, they are not immune to deleterious incidents, particularly concerning toxicity and the emergence of parasitic resistance, thus accentuating the necessity of exploring alternative avenues. Consequently, this research not only encompasses conventional therapeutic approaches, but also extends its scope to encompass complementary and alternative medicinal techniques, thereby striving to identify innovative solutions. A particularly auspicious dimension of this study lies in the exploration of natural substances and by-products derived from some brown algae of the Sargassaceae family. These resources possess the potential to assume a pivotal role in the management of leishmaniasis.

Combining donepezil and memantine via mannosylated PLGA nanoparticles for intranasal delivery: Characterization and preclinical studies

The current work is focused on developing mannose-coated PLGA nanoparticles for delivering Donepezil and Memantine in one dosage form. The formulated nanoparticles were prepared using a simple emulsification technique. The final coated NPs exhibited 179.4 nm size and - 33.1 mV zeta potential and spherical shape. The concentration of IN-administrated MEM and DPZ mannose coated NPs in brain was ~573 and 207 ng/mL respectively. This amount accounts for 3 times more in comparison to uncoated NPs administered via intranasal and peroral routes. The plasma concentration of coated NPs administered via the intranasal route was various times less in comparison to other groups. In the field of pharmacodynamics, the administration of coated NPs via the IN route has shown superior efficacy in comparison to other groups in various investigations involving neurobehavioral assessments, gene expression analyses and biochemical estimations. The findings indicate that the IN route may be a potential avenue for delivering therapeutic agents using nanoparticles to treat neurological illnesses. This approach shows promise as a viable alternative to traditional dose forms and administration methods.

Polymer-based particles against pathogenic fungi: A non-uptake delivery of compounds

The therapy of life-threatening fungal infections is limited and needs urgent improvement. This is in part due to toxic side effects of clinically used antifungal compounds or their limited delivery to fungal structures. Until today, it is a matter of debate how drugs or drug-delivery systems can efficiently reach the intracellular lumen of fungal cells and how this can be improved. Here, we addressed both questions by applying two different polymeric particles for delivery of compounds. Their formulation was based on two biocompatible polymers, i.e., poly(lactic-co-glycolic acid)_50:50 and poly(methyl methacrylate-stat-methacrylic acid)_90:10 yielding particles with hydrodynamic diameters ranging from 100 to 300 nm. The polymers were covalently labeled with the fluorescent dye DY-550 to monitor the interaction between particles and fungi by confocal laser scanning microscopy. Furthermore, the fluorescent dye coumarin-6 and the antifungal drug itraconazole were successfully encapsulated in particles to study the fate of both the cargo and the particle when interacting with the clinically most important human-pathogenic fungi Aspergillus fumigatus, A. terreus, Candida albicans, and Cryptococcus neoformans. While the polymers were exclusively located on the fungal surface, the encapsulated cargo was efficiently transported into fungal hyphae, indicated by increased intracellular fluorescence signals due to coumarin-6. In accordance with this finding, compared to the pristine drug a reduced minimal inhibitory concentration for itraconazole was determined, when it was encapsulated. Together, the herein used polymeric particles were not internalized by pathogenic fungi but were able to efficiently deliver hydrophobic cargos into fungal cells.

A Review on Recent Advances in Mannose-Functionalized Targeted Nanocarrier Delivery Systems in Cancer and Infective Therapeutics

Unmodified nanocarriers used in the chemotherapy of cancers and various infectious diseases exhibit prolonged blood circulation time, prevent enzymatic degradation and increase chemical stability of encapsulated therapeutics. However, off-target effect and lack of specificity associated with unmodified nanoparticles (NPs) limit their applications in the health care system. Mannose (Man) receptors with significant overexpression on antigen-presenting cells and macrophages are among the most admired targets for cancer and anti-infective therapeutics. Therefore, development of Man functionalized nanocarriers targeting Man receptors, for target specific drug delivery in the chemotherapy have been extensively studied. Present review expounds diverse Man-conjugated NPs with their potential for targeted drug delivery, improved biodistribution profiles and localization. Additionally, the review gives detailed account of the interactions of mannosylated NPs with various biological systems and their characterization not discussed in earlier published reports is discussed.

Potent antifungal agents and use of nanocarriers to improve delivery to the infected site: A systematic review

There are four major classes of antifungals with the predominant mechanism of action being targeting of cell wall or cell membrane. As in other drugs, low solubility of these compounds has led to low bioavailability in target tissues. Enhanced drug dosages have effects such as toxicity, drug-drug interactions, and increased drug resistance by fungi. This article reviews the current state-of-the-art of antifungals, structure, mechanism of action, other usages, and toxic side effects. The emergence of nanoformulations to transport and uniformly release cargo at the target site is a boon in antifungal treatment. The article details research that lead to the development of nanoformulations of antifungals and potential advantages and avoidance of the lacunae characterizing conventional drugs. A range of nanoformulations based on liposomes, polymers are in various stages of research and their potential advantages have been brought out. It could be observed that under similar dosages, test models, and duration, nanoformulations provided enhanced activity, reduced toxicity, higher uptake and higher immunostimulatory effects. In most instances, the mechanism of antifungal activity of nanoformulations was similar to that of regular antifungal. There are possibilities of coupling multiple antifungals on the same nano-platform. Increased activity coupled with multiple mechanisms of action presents for nanoformulations a tremendous opportunity to overcome antifungal resistance. In the years to come, robust methods for the preparation of nanoformulations taking into account the repeatability and reproducibility in action, furthering the studies on nanoformulation toxicity and studies of human models are required before extensive use of nanoformulations as a prescribed drug.

Functional Nanocarriers for Delivering Itraconazole Against Fungal Intracellular Infections

Infectious diseases caused by intracellular microorganisms represent a significant challenge in medical care due to interactions among drugs during coinfections and the development of resistance in microorganisms, limiting existing therapies. This work reports on itraconazole (ITZ) encapsulated into functional polymeric nanoparticles for their targeted and controlled release into macrophages to fight intracellular infections. NPs are based on poly (lactic acid-co-glycolic acid) (PLGA) polymers of different compositions, molecular weights, and lactic acid–to–glycolic acid ratios. They were self-assembled using the high-energy nanoemulsion method and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry. It was studied how the polymer-to-drug ratio, changes in the aqueous phase pH, and type and concentration of surfactant affected nanocarriers’ formation, drug-loading capacity, and encapsulation efficiency. Results showed that drug-loading capacity and encapsulation efficiency reached 6.7 and 80%, respectively, by lowering the pH to 5.0 and using a mixture of surfactants. Optimized formulation showed an initial immediate ITZ release, followed by a prolonged release phase that fitted better with a Fickian diffusion kinetic model and high stability at 4 and 37°C. NPs functionalized by using the adsorption and carbodiimide methods had different efficiencies, the carbodiimide approach being more efficient, stable, and reproducible. Furthermore, linking F4/80 and mannose to the NPs was demonstrated to increase J774A.1 macrophages’ uptake. Overall, in vitro assays showed the nanosystem’s efficacy to eliminate the Histoplasma capsulatum fungus and pave the way to design highly efficient nanocarriers for drug delivery against intracellular infections.

An Overview on the Therapeutics of Neglected Infectious Diseases-Leishmaniasis and Chagas Diseases

Neglected tropical diseases (NTDs) as termed by WHO include twenty different infectious diseases that are caused by bacteria, viruses, and parasites. Among these NTDs, Chagas disease and leishmaniasis are reported to cause high mortality in humans and are further associated with the limitations of existing drugs like severe toxicity and drug resistance. The above hitches have rendered researchers to focus on developing alternatives and novel therapeutics for the treatment of these diseases. In the past decade, several target-based drugs have emerged, which focus on specific biochemical pathways of the causative parasites. For leishmaniasis, the targets such as nucleoside analogs, inhibitors targeting nucleoside phosphate kinases of the parasite’s purine salvage pathway, 20S proteasome of Leishmania, mitochondria, and the associated proteins are reviewed along with the chemical structures of potential drug candidates. Similarly, in case of therapeutics for Chagas disease, several target-based drug candidates targeting sterol biosynthetic pathway (C14-ademethylase), L-cysteine protease, heme peroxidation, mitochondria, farnesyl pyrophosphate, etc., which are vital and unique to the causative parasite are discussed. Moreover, the use of nano-based formulations towards the therapeutics of the above diseases is also discussed.

Preparation and characterization of itraconazole loaded nanomicelles based on dextran-behenic acid for cutaneous leishmaniasis treatment

Cutaneous leishmaniasis is known as the most prevalent clinical form of leishmaniasis. It needs the development of new therapies due to the serious side-effects promoted by taking the current drugs. In the present study, dextran-behenic acid (DEX-BA) based nanomicelles were developed to direct the delivery of itraconazole (ITZ) to the macrophages and enhance its toxic effects against Leishmania parasites. DEX-BA was synthesized through the esterification of dextran with behenic acid. The critical micelle concentration of the newly developed conjugate was evaluated using pyrene as the fluorescent probe. The nanomicelles were generated by the dialysis method; then they were optimized by applying a Box-Behnken design. The effects of the dialysis temperature, polymer content, and sonication time on the characteristics of micelles were subsequently studied. Furthermore, in vitro efficacy against Leishmania major promastigotes and parasite-infected macrophages was evaluated. The optimized formulation showed the particle size of 195.16 ± 3.06 nm, the polydispersity index of 0.39 ± 0.01, the zeta potential of -16.29 ± 0.89 mV, the encapsulation efficiency % of 56.11 ± 4.9, and the release efficiency % of 51.29 ± 1.97. According to scanning electron microscopy, the nanomicelles were found to be nearly spherical in shape. ITZ-loaded nanomicelles showed the strongest anti-leishmanial activities when compared with the free ITZ and drug-free nanomicelles. It could be, therefore, concluded that ITZ-loaded nanomicelles might be useful as an alternative therapy for the treatment of cutaneous leishmania.

Recent Advances in Polymeric Nanoparticle-Encapsulated Drugs against Intracellular Infections

Polymeric nanocarriers (PNs) have demonstrated to be a promising alternative to treat intracellular infections. They have outstanding performance in delivering antimicrobials intracellularly to reach an adequate dose level and improve their therapeutic efficacy. PNs offer opportunities for preventing unwanted drug interactions and degradation before reaching the target cell of tissue and thus decreasing the development of resistance in microorganisms. The use of PNs has the potential to reduce the dose and adverse side effects, providing better efficiency and effectiveness of therapeutic regimens, especially in drugs having high toxicity, low solubility in the physiological environment and low bioavailability. This review provides an overview of nanoparticles made of different polymeric precursors and the main methodologies to nanofabricate platforms of tuned physicochemical and morphological properties and surface chemistry for controlled release of antimicrobials in the target. It highlights the versatility of these nanosystems and their challenges and opportunities to deliver antimicrobial drugs to treat intracellular infections and mentions nanotoxicology aspects and future outlooks.

Drug delivery to macrophages: a review of nano-therapeutics targeted approach for inflammatory disorders and cancer

INTRODUCTION

Macrophages are involved in the normal defense of the body; however, the varying phenotypes of macrophages and imbalance in their ratio lead to the impairment of immune response initiating the production of inflammation. As the role of macrophages in immunological disorders and their surface receptors modulation has already been manifested; hence, macrophages can be exploited to make them a viable candidate for targeted delivery, which was not possible with previously designed conventional therapies for the immune disorders.

AREAS COVERED

Nanotechnology is a promising, clear cut, efficient, and adequate approach for targeting macrophages. Literature addresses the receptors available for targeting and the novel small dimensional therapeutic delivery vehicles to target them along with a brief overview of the role of macrophages in these diseases. Furthermore, the patents based on this idea are also listed.

EXPERT OPINION

Targeted drug delivery to macrophages should take into consideration the plasticity of macrophages and their modulation over time in the diseases. A cost-effective scale-up method of development will further facilitate the clinical trials. Besides, the implementation of safety guidelines to target macrophages and the studies of long-term effects of targeted approaches in humans would highly encourage the clinical outcomes.