pH-sensitive nanoparticles for improved oral delivery of dapsone: risk assessment, design, optimization and characterization

Leprosy: Comprehensive insights into pathology, immunology, and cutting-edge treatment strategies, integrating nanoparticles and ethnomedicinal plants

Mycobacterium leprae is the causative agent responsible for the chronic disease known as leprosy. This condition is characterized by dermal involvement, often leading to peripheral nerve damage, sensory-motor loss, and related abnormalities. Both innate and acquired immunological responses play a role in the disease, and even in individuals with lepromatous leprosy, there can be a transient increase in T cell immunity during lepromatous reactions. Diagnosing of early-stage leprosy poses significant challenges. In this context, nanoparticles have emerged as a promising avenue for addressing various crucial issues related to leprosy. These include combatting drug resistance, mitigating adverse effects of conventional medications, and enhancing targeted drug delivery. This review serves as a comprehensive compilation, encompassing aspects of pathology, immunology, and adverse effects of multidrug delivery systems in the context of leprosy treatment. Furthermore, the review underscores the significance of ethnomedicinal plants, bioactive secondary metabolites, and nanotherapeutics in the management of leprosy. It emphasizes the potential to bridge the gap between existing literature and ongoing research efforts, with a profound scope for validating traditional claims, developing herbal medicines, and formulating nanoscale drug delivery systems that are safe, effective, and widely accepted.

pH-responsive phthalate cashew gum nanoparticles for improving drugs delivery and anti-Trypanosoma cruzi efficacy

Nanotechnology is a crucial technology in recent years has resulted in new and creative applications of nanomedicine. Polymeric nanoparticles have increasing demands in pharmaceutical applications and require high reproducibility, homogeneity, and control over their properties. Work explores the use of cashew phthalate gum (PCG) as a particle-forming polymer. PCG exhibited a pH-sensitive behavior due to the of acid groups on its chains, and control drug release. We report the development of nanoparticles carrying benznidazole. Formulations were characterized by DLS, encapsulation efficiency, drug loading, FTIR, pH-responsive behavior, release, and in vitro kinetics. Interaction between polymer and drug was an evaluated by molecular dynamics. Morphology was observed by SEM, and in vitro cytotoxicity by MTT assay. Trypanocidal effect for epimastigote and trypomastigote forms was also evaluated. NPs responded to the slightly basic pH, triggering the release of BNZ. In acidic medium, they presented small size, spherical shape, and good stability. It was indicated NP with enhanced biological activity, reduced cytotoxicity, high anti T. cruzi performance, and pH-sensitive release. This work investigated properties related to the development and enhancement of nanoparticles. PCG has specific physicochemical properties that make it a promising alternative to drug delivery, however, there are still challenges to be overcome.

Impact of nanoparticles on amyloid β-induced Alzheimer's disease, tuberculosis, leprosy and cancer: a systematic review

Nanotechnology is an interdisciplinary domain of science, technology and engineering that deals with nano-sized materials/particles. Usually, the size of nanoparticles lies between 1 and 100 nm. Due to their small size and large surface area-to-volume ratio, nanoparticles exhibit high reactivity, greater stability and adsorption capacity. These important physicochemical properties attract scientific community to utilize them in biomedical field. Various types of nanoparticles (inorganic and organic) have broad applications in medical field ranging from imaging to gene therapy. These are also effective drug carriers. In recent times, nanoparticles are utilized to circumvent different treatment limitations. For example, the ability of nanoparticles to cross the blood-brain barrier and having a certain degree of specificity towards amyloid deposits makes themselves important candidates for the treatment of Alzheimer's disease. Furthermore, nanotechnology has been used extensively to overcome several pertinent issues like drug-resistance phenomenon, side effects of conventional drugs and targeted drug delivery issue in leprosy, tuberculosis and cancer. Thus, in this review, the application of different nanoparticles for the treatment of these four important diseases (Alzheimer's disease, tuberculosis, leprosy and cancer) as well as for the effective delivery of drugs used in these diseases has been presented systematically. Although nanoformulations have many advantages over traditional therapeutics for treating these diseases, nanotoxicity is a major concern that has been discussed subsequently. Lastly, we have presented the promising future prospective of nanoparticles as alternative therapeutics. In that section, we have discussed about the futuristic approach(es) that could provide promising candidate(s) for the treatment of these four diseases.

Highly water-soluble dapsone nanocrystals: Towards innovative preparations for an undermined drug

Dapsone (DAP)is a dual-function drug substance; however, its limited water solubility may impair its bioavailability. Drug nanocrystals are an alternative to overcome this limitation. Herein, a DAP nanosuspension was prepared using adesign space approach aiming to investigate the influence of raw material properties and process parameters on the critical quality attributes of the drugnanocrystals. Optimized nanocrystals with 206.3 ± 6.7 nm using povacoat™ as stabilizer were made. The nanoparticles were characterized by dynamic light scattering, laser diffraction, scanning electron microscopy, differential scanning calorimetry, X-ray powder diffraction, and saturation solubility. Compared to the raw material, the nanocrystals were 250-times smaller. Meanwhile, its crystalline state remained basically unchanged even after milling and drying. The nanosuspension successfully maintained its physical stability inlong-termandaccelerated stability studiesover, 4 and 3 months. Furthermore, toxicity studiesshowed low a toxicity at a20 mg/kg. As expected for nanocrystals, the size reduction improvedsaturation solubility3.78 times in water. An attempt to scale up from lab to pilot scale resulted nanocrystals of potential commercial quality. In conclusion, the present study describes the development of dapsone nanocrystals for treating infectious and inflammatory diseases. The nanocrystal formuation can be scaled up for commercial use.

Eco-friendly synthesis of phthalate angico gum towards nanoparticles engineering using Quality by Design (QbD) approach

We developed a new hydrophobic polymer based on angico gum (AG), and we produced new nanoparticles to expand the applications of natural polysaccharides in nanomedicine. Phthalate angico gum (PAG) was characterized by ¹H NMR, FTIR, elementary analysis, solubility, XRD, and TG. PAG was a hydrophobic and semi-crystalline material, a relevant characteristic for drug delivery system applications. As a proof of concept, nevirapine (NVP) was selected for nanoparticles development. Plackett-Burman's experimental design was used to understand the influence of several factors in nanoparticles production. PAG proved to be a versatile material for producing nanoparticles with different characteristics. Optimized nanoparticles were produced using desirability parameters. NVP-loaded PAG nanoparticles formulation showed 202.1 nm of particle size, 0.23 of PDI, -17.1 of zeta potential, 69.8 of encapsulation efficiency, and promoted modified drug release for 8 h. Here we show that PAG presents as a promising biopolymer for drug delivery systems.

Drug Delivery Systems on Leprosy Therapy: Moving Towards Eradication?

Leprosy disease remains an important public health issue as it is still endemic in several countries. Mycobacterium leprae, the causative agent of leprosy, presents tropism for cells of the reticuloendothelial and peripheral nervous system. Current multidrug therapy consists of clofazimine, dapsone and rifampicin. Despite significant improvements in leprosy treatment, in most programs, successful completion of the therapy is still sub-optimal. Drug resistance has emerged in some countries. This review discusses the status of leprosy disease worldwide, providing information regarding infectious agents, clinical manifestations, diagnosis, actual treatment and future perspectives and strategies on targets for an efficient targeted delivery therapy.

Formulation and in vivo efficacy study of cetuximab decorated targeted bioadhesive nanomedicine for non-small-cell lung cancer therapy

Aim: To design, optimize and evaluate docetaxel-loaded chitosan nanoparticles with (targeted) and without (nontargeted) cetuximab conjugation for the treatment of non-small-cell lung cancer (NSCLC). Materials & methods: Risk-assessment, optimization, in vitro characterizations, stability assessments, release studies, cell-culture studies were performed along with histopathology, pharmacokinetic and anticancer efficacy studies. Results: The nanoparticles of desired particle size (152.59 ± 3.90 nm to 180.63 ± 5.21 nm) which could sustain drug release for up to 70 h, were obtained. The cell-culture studies demonstrated the superiority of the formulations over Docel™. The pharmacokinetic evaluation showed the excellent systemic bioavailability of prepared NPs. The histopathology screening revealed lesser toxicity of both the nontargeted and targeted formulations. The targeted nanoformulation significantly reduced tumor growth than the nontargeted formulation and Docel. Conclusion: These results demonstrate the therapeutic potential of the prepared nanoformulation. After proper clinical validation, it could be a promising approach for the treatment of NSCLC.

pH-responsive chitosan based hydrogels affect the release of dapsone: Design, set-up, and physicochemical characterization

Dapsone (DAP) is a bactericidal agent used in the treatment of leprosy, caused by Mycobacterium leprae. Despite its therapeutic potential, DAP has low solubility, which results in allow therapeutic index and a high microbial resistance. Recently, new approaches were used to increase the DAP solubility. In particular, the use of interpenetrating polymer network (IPN)-hydrogels based chitosan (CS) for the controlled release of DAP provides some advantages because they can modify their swelling properties and network structures as a response to environmental stimuli. The aim of this study was to synthesize and physicochemically characterize pH-responsive chitosan/polymer hydrogels to control the release of DAP. For this reason, different combination of polymers, such as polyvinyl pyrrolidone, polyethylene glycol and hydroxypropyl methylcellulose, and concentrations of the cross-linking agents (glutaraldehyde) were used and then blended to the CS. The resulting hydrogels were evaluated in terms of physicochemical and swelling properties, rheological analysis and in vitro release of DAP at different pHs (1.2-6.8). Hydrogels were further characterized by Fourier transformed infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) analysis. pH-responsive DAP-loaded hydrogels may represent the set-up for developing potential oral formulations for the treatment of leprosy caused by Mycobacterium leprae.

Nanosystems as modulators of intestinal dapsone and clofazimine delivery

The aim of this work was to assess the feasibility of drug nanosystems combination for oral therapy of multibacillary leprosy. The anti-leprotic drugs dapsone (DAP) and clofazimine (CLZ) were incorporated within polymeric nanosystems and studied per se and in combination. DAP was loaded in Eudragit L100 nanoparticles (NPs-DAP) while CLZ was loaded in (poly(lactic-co-glycolic acid) (NPs-CLZ). The nanosystems exhibited around 200 nm in size and a drug loading of 12% for each drug. In vitro cytotoxicity on intestinal Caco-2 cells revealed that after 8 h incubation, DAP alone and within NPs were not toxic up to 100 μg mL^-1, while CLZ per se was toxic, reducing cell viability to 30% at 50 μg mL^-1. Caco-2 exposed to the combination of NPs-DAP (100 μg mL^-1) and NPs-CLZ (50 μg mL^-1) exhibited 80% of viability. Caco-2 monolayer permeability assays revealed that DAP and CLZ in the nanosystems per se or in NPs-DAP/ NPs-CLZ combination crossed the intestinal barrier. No significant differences were observed between the single nanosystems or in combination with the apparent permeability values and the amount of permeated drug. Thus, the NPs-DAP/NPs-CLZ combination seems to be a promising platform to deliver both drugs in association, representing an important step towards the improvement of multibacillary leprosy therapy.

An insight of in vitro transport of PEGylated non-ionic surfactant vesicles (NSVs) across the intestinal polarized enterocyte monolayers

PEGylated non-ionic surfactant-based vesicles (NSVs) are promising drug delivery systems for the local, oral and systemic administrations of therapeutics. The aim of this study was to test the cellular biocompatibility and transport of Nile Red-loaded NSVs (NR-NSVs) across the Caco-2-cell monolayers, which represent an in vitro model of human intestinal epithelium. The NR-NSVs assumed a spherical shape with a mean size of 140 nm, and a narrow size distribution. The NR-NSVs did not modify Caco-2 cell viability, which remained unaltered in vitro up to a concentration of 1 mM. The transport studies demonstrated that the NR-NSVs moved across the Caco-2 monolayers without affecting the transepithelial electrical resistance. These results were supported by flow cytometry analysis, which demonstrated that NR-NSVs were internalized inside the Caco-2 cells. Nanoparticle tracking and Transmission Electron Microscopy (TEM) analysis showed the presence of NR-NSVs in the basolateral side of the Caco-2 monolayers. TEM images also showed that NSVs were transported intact across the Caco-2 monolayers, thus demonstrating a predominant transcytosis mechanism of transport through endocytosis. The NSVs did not affect the integrity of the membrane barrier in vitro, and can potentially be used in clinics to increase the oral bioavailability and delivery of therapeutics.