Development and evaluation of protamine-coated PLGA nanoparticles for nose-to-brain delivery of tacrine: In-vitro and in-vivo assessment

An insight into structure-activity relationship of naturally derived biological macromolecules for the treatment of Alzheimer's disease: a review

Alzheimer's disease (AD) is a neurological disorder that affects millions of people worldwide. There are currently no cures for AD, although various drugs are used to manage the symptoms and reduce the disease's progression. AChE inhibitors such as rivastigmine, donepezil, galantamine, and the NMDA glutamate receptor antagonist memantine are currently FDA-approved drugs used in the treatment of AD. Recently, naturally derived biological macromolecules have shown promising results in the treatment of AD. Several biological macromolecules derived from natural sources are in various stages of preclinical and clinical trials. During the literature search, it was observed that there is a lack of a comprehensive review that particularly focuses on the role of naturally derived biological macromolecules (protein, carbohydrates, lipids, and nucleic acids) in the treatment of AD and the structure-activity relationship (SAR) approach for understanding the medicinal chemistry perspective. This review focuses on the SAR and probable mechanisms of action of biological macromolecules derived from natural sources for the treatment of AD, including peptides, proteins, enzymes, and polysaccharides. The paper further addresses the therapeutic possibilities of monoclonal antibodies, enzymes, and vaccines for the treatment of AD. Overall, the review provides insight into the SAR of naturally derived biological macromolecules in the treatment of AD. The ongoing research in this field holds great promise for the future development of AD treatment and provides hope for individuals affected by this devastating disease.Communicated by Ramaswamy H. Sarma.

Nanotechnology-based delivery of therapeutics through the intranasal pathway and the blood-brain barrier for Alzheimer's disease treatment

Background: drugs for Alzheimer's disease (AD) fail to exhibit efficacy in clinical trials for a number of reasons, a major one being blood-brain barrier (BBB) permeability. Meanwhile, the increasing incidence of this disease emphasizes the need for effective therapeutics. Herein, we discuss novel nanoplatform technologies developed for the effective delivery of AD drugs by traversing the BBB. Main text: the interfacial and surface chemistry of nanomaterials is utilized in several industries, including pharmaceutical, and has drawn considerable attention in the field of nanotechnology. Various reports have suggested the potential of nanotechnology for AD treatment, describing unique drug carriers that improve drug stability and solubility while maintaining therapeutic dosages. These nanotechnologies are harnessed for the transport of drugs across the BBB, with or without surface modifications. We also discuss the transfer of drugs via the nose-to-brain pathway, as intranasal delivery enables direct drug distribution in the brain. In addition, nanomaterial modifications that prolong drug delivery and improve safety following intranasal administration are addressed. Conclusion: although several studies have yielded promising results, limited efforts have been undertaken to translate research findings into clinical contexts. Nevertheless, nanomaterials hold considerable potential for the development of novel effective therapeutic solutions against AD.

Intranasal Drug Delivery by Nanotechnology: Advances in and Challenges for Alzheimer's Disease Management

Alzheimer's disease, a progressive neurodegenerative condition, is characterized by a gradual decline in cognitive functions. Current treatment approaches primarily involve the administration of medications through oral, parenteral, and transdermal routes, aiming to improve cognitive function and alleviate symptoms. However, these treatments face limitations, such as low bioavailability and inadequate permeation. Alternative invasive methods, while explored, often entail discomfort and require specialized assistance. Therefore, the development of a non-invasive and efficient delivery system is crucial. Intranasal delivery has emerged as a potential solution, although it is constrained by the unique conditions of the nasal cavity. An innovative approach involves the use of nano-carriers based on nanotechnology for intranasal delivery. This strategy has the potential to overcome current limitations by providing enhanced bioavailability, improved permeation, effective traversal of the blood-brain barrier, extended retention within the body, and precise targeting of the brain. The comprehensive review focuses on the advancements in designing various types of nano-carriers, including polymeric nanoparticles, metal nanoparticles, lipid nanoparticles, liposomes, nanoemulsions, Quantum dots, and dendrimers. These nano-carriers are specifically tailored for the intranasal delivery of therapeutic agents aimed at combatting Alzheimer's disease. In summary, the development and utilization of intranasal delivery systems based on nanotechnology show significant potential in surmounting the constraints of current Alzheimer's disease treatment strategies. Nevertheless, it is essential to acknowledge regulatory as well as toxicity concerns associated with this route; meticulous consideration is required when engineering a carrier. This comprehensive review underscores the potential to revolutionize Alzheimer's disease management and highlights the importance of addressing regulatory considerations for safe and effective implementations. Embracing this strategy could lead to substantial advancements in the field of Alzheimer's disease treatment.

Nanocarrier-Based Drug Delivery to Brain: Interventions of Surface Modification

Brain disorders are a prevalent and rapidly growing problem in the medical field as they adversely affect the quality of life of a human. With an increase in life expectancy, it has been reported that diseases like Alzheimer's, Parkinson's, stroke and brain tumors, along with neuropsychological disorders, are also being reported at an alarmingly high rate. Despite various therapeutic methods for treating brain disorders, drug delivery to the brain has been challenging because of a very complex Blood Brain Barrier, which precludes most drugs from entering the brain in effective concentrations. Nano-carrier-based drug delivery systems have been reported widely by researchers to overcome this barrier layer. These systems due to their small size, offer numerous advantages; however, their short residence time in the body owing to opsonization hinders their success in vivo. This review article focuses on the various aspects of modifying the surfaces of these nano-carriers with polymers, surfactants, protein, antibodies, cell-penetrating peptides, integrin binding peptides and glycoproteins such as transferrin & lactoferrin leading to enhanced residence time, desirable characteristics such as the ability to cross the blood-brain barrier (BBB), increased bioavailability in regions of the brain and targeted drug delivery.

Meta-Analysis: A Convenient Tool for the Choice of Nose-to-Brain Nanocarriers

OBJECTIVES

The intranasal route represents a high promising route of administration aiming for brain delivery. Yet, it represents one of the most difficult and complicated routes. Accordingly, scientists are in a continuous search for novel drug delivery vehicles such as the lipid and polymeric nanoparticles that are apt to enhance the bioavailability of the administered drugs to reach the brain. In this study, a certain number of publications were selected from different databases and literature. Meta-analysis studies using two different algorithms (DerSimonian-Laird and inverse variance) followed aiming to explore the published studies and confirm by evidence the superiority of nanocarriers in enhancing the brain bioavailability of various drugs. Furthermore, the quantitative comparison of lipid versus polymeric nanosystems was performed.

METHODS

The area under the curve (AUC) as an important pharmacokinetic parameter extracted from in vivo animal studies was designated as the "effect" in the performed meta-analysis after normalization. Forest plots were generated.

KEY FINDINGS AND CONCLUSIONS

The meta-analysis confirmed the augmentation of the AUC after the comparison with traditional preparations such as solutions and suspensions. Most importantly, lipid nanoparticles were proven to be significantly superior to the polymeric counterparts.

Amyloid β, Lipid Metabolism, Basal Cholinergic System, and Therapeutics in Alzheimer’s Disease

The presence of insoluble aggregates of amyloid β (Aβ) in the form of neuritic plaques (NPs) is one of the main features that define Alzheimer’s disease. Studies have suggested that the accumulation of these peptides in the brain significantly contributes to extensive neuronal loss. Furthermore, the content and distribution of cholesterol in the membrane have been shown to have an important effect on the production and subsequent accumulation of Aβ peptides in the plasma membrane, contributing to dysfunction and neuronal death. The monomeric forms of these membrane-bound peptides undergo several conformational changes, ranging from oligomeric forms to beta-sheet structures, each presenting different levels of toxicity. Aβ peptides can be internalized by particular receptors and trigger changes from Tau phosphorylation to alterations in cognitive function, through dysfunction of the cholinergic system. The goal of this review is to summarize the current knowledge on the role of lipids in Alzheimer’s disease and their relationship with the basal cholinergic system, as well as potential disease-modifying therapies.

Intranasal Administration of a TRAIL Neutralizing Monoclonal Antibody Adsorbed in PLGA Nanoparticles and NLC Nanosystems: An In Vivo Study on a Mouse Model of Alzheimer’s Disease

Alzheimer’s disease (AD) is a neurodegenerative disorder that progressively compromises cognitive functions. Tumor necrosis factor (TNF)-Related Apoptosis Inducing Ligand (TRAIL), a proinflammatory cytokine belonging to the TNF superfamily, appears to be a key player in the inflammatory/immune orchestra of the AD brain. Despite the ability of an anti-TRAIL monoclonal antibody to reach the brain producing beneficial effects in AD mice, we attempted to develop such a TRAIL-neutralizing monoclonal antibody adsorbed on lipid and polymeric nanocarriers, for intranasal administration, in a valid approach to overcome issues related to both high dose and drug transport across the blood–brain barrier. The two types of nanomedicines produced showed physico-chemical characteristics appropriate for intranasal administration. As confirmed by enzyme-linked immunosorbent assay (ELISA), both nanomedicines were able to form a complex with the antibody with an encapsulation efficiency of ≈99%. After testing in vitro the immunoneutralizing properties of the nanomedicines, the latter were intranasally administered in AD mice. The antibody–nanocarrier complexes were detectable in the brain in substantial amounts at concentrations significantly higher compared to the free form of the anti-TRAIL antibody. These data support the use of nanomedicine as an optimal method for the delivery of the TRAIL neutralizing antibody to the brain through the nose-to-brain route, aiming to improve the biological attributes of anti-TRAIL-based therapy for AD treatment.

The Tragedy of Alzheimer's Disease: Towards Better Management via Resveratrol-Loaded Oral Bilosomes

Alzheimer's disease (AD) is a neurodegenerative disease where oxidative stress plays a major role as a key pathologic factor. The study aims to develop resveratrol (RES)-loaded bilosomes for oral use, aiming to enhance RES bioavailability. RES-loaded bilosomes were prepared using the thin-film hydration technique. The effect of different formulation variables viz. the number of extrusion cycles, drug concentration and the effect of pH of the medium and cholesterol addition on the physicochemical properties of the prepared bilosomes was investigated. Results revealed the successful entrapment of RES into bilosomes. An optimized formula was selected, showing the lowest particle size (189 ± 2.14), acceptable PDI (0.116) and entrapment efficiency (76.2 ± 1.36). In vivo studies on a streptozotocin-induced animal model of AD showed the preeminence of bilosomes over traditional drug suspension to enhance mice memory via Y-maze and Morris water maze tests. Moreover, mice treated with the optimized formula exhibited decreased COX2, IL-6, amyloid-beta peptide and Tau protein levels compared to the drug suspension. Immuno-histochemical analysis revealed a significant decrease of glial fibrillary acidic protein values and microglial cell count in mice treated with bilosomes. Finally, it could be advocated that RES-loaded bilosomes could be a promising drug delivery system to control AD.

Optimization of Hyaluronate-Based Liposomes to Augment the Oral Delivery and the Bioavailability of Berberine

Various perspectives had been utilized to enhance the poor intestinal permeability and bioavailability of drugs with low water solubility. Berberine (Brb) is a unique molecule that possesses multiple therapeutic activities such as antimicrobial, anti-inflammatory, antioxidant and anti-hyperglycemic effects. To improve Brb permeability and bioavailability, this study presents a newly developed formulation, namely Brb hyaluronate-based liposomes, prepared by using film hydration method and characterized by dynamic light scattering measurements, entrapment efficiency percentage (EE%), transmission electron microscope (TEM), in vitro drug release and physical stability. The bioavailability of the selected formulations was assessed in vivo after oral administration to rats. The results revealed an enhanced effect of hyaluronic acid on the entrapment efficiency, reaching 78.1 ± 0.1% with mean size 520.7 ± 19.9 nm. Sustained release of Brb was recorded up to 24 h in comparison to Brb solution. Physical stability was maintained for three months at refrigeration temperature. Results of pharmacokinetics studies indicated the potential of the liposomal formulation to increase the oral bioavailability of Brb and to accelerate its entry into the bloodstream. The obtained results are accredited to the lipophilic nature of the prepared system, resembling the structural features of bio-membrane, in addition to their small size that enhances intestinal penetration.

A comparison study of lipid and polymeric nanoparticles in the nasal delivery of meloxicam: Formulation, characterization, and in vitro evaluation

With the increasingly widespread of central nervous system (CNS) disorders and the lack of sufficiently effective medication, meloxicam (MEL) has been reported as a possible medication for Alzheimer's disease (AD) management. Unfortunately, following the conventional application routes, the low brain bioavailability of MEL forms a significant limitation. The intranasal (IN) administration route is considered revolutionary for CNS medications delivery. The objective of the present study was to develop two types of nanocarriers, poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) and solid lipid nanoparticles (SLNs), for the IN delivery of MEL adapting the Quality by Design approach (QbD). Turning then to further enhance the optimized nanoformulation behavior by chitosan-coating. SLNs showed higher encapsulation efficacy (EE) and drug loading (DL) than PLGA NPs 87.26% (EE) and 2.67% (DL); 72.23% (EE) and 2.55% (DL), respectively. MEL encapsulated into the nanoformulations improved in vitro release, mucoadhesion, and permeation behavior compared to the native drug with greater superiority of chitosan-coated SLNs (C-SLNs). In vitro-in vivo correlation (IVIVC) results estimated a significant in vivo brain distribution of the nanoformulations compared to native MEL with estimated greater potential in the C-SLNs. Hence, MEL encapsulation into C-SLNs towards IN route can be promising in enhancing its brain bioavailability.

Bioactive Ibuprofen-Loaded PLGA Coatings for Multifunctional Surface Modification of Medical Devices

To modulate the biofunctionality of implantable medical devices commonly used in clinical practice, their surface modification with bioactive polymeric coatings is an attractive and successful emerging strategy. Biodegradable coatings based on poly(lactic acid-co-glycolic acid), PLGA, represent versatile and safe candidates for surface modification of implantable biomaterials and devices, providing additional tunable ability for topical delivery of desired therapeutic agents. In the present study, Ibuprofen-loaded PLGA coatings (PLGA/IBUP) were obtained by using the dip-coating and drop-casting combined protocol. The composite materials demonstrated long-term drug release under biologically simulated dynamic conditions. Reversible swelling phenomena of polymeric coatings occurred in the first two weeks of testing, accompanied by the gradual matrix degradation and slow release of the therapeutic agent. Irreversible degradation of PLGA coatings occurred after one month, due to copolymer's hydrolysis (evidenced by chemical and structural modifications). After 30 days of dynamic testing, the cumulative release of IBUP was ~250 µg/mL. Excellent cytocompatibility was revealed on human-derived macrophages, fibroblasts and keratinocytes. The results herein evidence the promising potential of PLGA/IBUP coatings to be used for surface modification of medical devices, such as metallic implants and wound dressings.