Self-Assembled Lecithin-Chitosan Nanoparticles Improved Rotigotine Nose-to-Brain Delivery and Brain Targeting Efficiency

Discovering the anti-parasitic activity of melatonin loaded lecithin/chitosan nanoparticles against giardiasis and cryptosporidiosis in Balb/c infected mice

Background

Giardia duodenalis and Cryptosporidium parvum are the primary causes of diarrhea with global attention due to the severe pathophysiological changes leading to mortality. During this study, we explored the biological protozoal contaminants (Giardia and Cryptosporidium spp.) in some areas of the Nile River. Then, we evaluated effectiveness of melatonin (Mel) and melatonin loaded lecithin/chitosan nanoparticles (Mel-LCNPs) against giardiasis and cryptosporidiosis in mice models using parasitological and inflammatory response examination.

Results

The number of positive samples for Cryptosporidium was higher than that for Giardia with percentage of 46.67% and 40.0%, respectively. Prior to treatment, the physical characterization (hydrodynamic size and zeta potential) and in vitro characterization of Mel-LCNPs were carried. Mel-LCNPs revealed a hydrodynamic size of 78.8 nm and a zeta potential of − 27.2 mV. Furthermore, they have powerful antioxidant and anti-inflammatory properties, while displaying minimal anticoagulant and cytotoxic effects during in vivo evaluation. Mel was consistently discharged from nanoparticles in a regulated and enduring manner for 36 h. Moreover, Mel in NPs has an entrapment efficiency (EE) of 33.6% and a drug loading capacity (DLC) of 7.2% and significant reduction (100% and 99.4%, respectively) in the shedding of Giardia cysts and Cryptosporidium oocysts. This reduction was higher than that observed with Mel alone or LCNPs alone on the 14th day post-infection. Moreover, mice of group V, which received Mel-LCNP treatment, exhibited significantly normal levels of interleukin-4 (IL-4) and interferon-gamma (IFN-γ) as well as healthy control mice group (group I).

Conclusion

Mel-LCNPs were highly effective preparations against giardiasis and cryptosporidiosis in Balb/c mice experimentally infected with proved antioxidant, anti-inflammatory, and immunological modulatory characteristics.

Supramolecular cyclodextrin-based reservoir as nasal delivery vehicle for rivastigmine to brain

The purpose of this study involved the synthesis of supramolecular reservoir (i.e. cyclodextrin metal-organic framework, MOF) using cyclodextrins as building blocks, followed by cross-linking to obtain crosslinked CD framework (CDF) using CD-MOF as template and functionalized with borneol (BO) to enhance rivastigmine (RIV) permeation and facilitate brain targeting via intranasal administration. Utilizing BO modified CDF (BO-CDF) with cubic shape as a carrier for the encapsulation of RIV, a nasal RIV delivery system (RIV@BO-CDF) was fabricated. The particle size of RIV@BO-CDF was approximately 250 nm, and the drug loading capacity reached 15 ± 2 %. BO-CDF improved the mucoadhesion and enhanced RIV permeability with the plasma concentration-time curve (AUC), the brain AUC and the peak drug concentration within brain in rats 1.7, 2.3 and 8 times than that of oral RIV solution, respectively. The relative drug targeting efficiency percentage (DTE, 139.4 %) and direct drug transfer percentage (DTP, 28.3 %) of RIV@BO-COF indicated good targeting efficiency and direct nose-to-brain drug delivery. Overall, this study provides a potential application of supramolecular cyclodextrin-based reservoir to enhance the brain targeting and efficacy of the RIV via nasal delivery.

Nanotechnological approaches for efficient N2B delivery: from small-molecule drugs to biopharmaceuticals

Central nervous system diseases negatively affect patients and society. Providing successful noninvasive treatments for these diseases is challenging because of the presence of the blood-brain barrier. While protecting the brain's homeostasis, the barrier limits the passage of almost all large-molecule drugs and most small-molecule drugs. A noninvasive method, nose-to-brain delivery (N2B delivery) has been proposed to overcome this challenge. By exploiting the direct anatomical interaction between the nose and the brain, the drugs can reach the target, the brain. Moreover, the drugs can be encapsulated into various drug delivery systems to enhance physicochemical characteristics and targeting success. Many preclinical data show that this strategy can effectively deliver biopharmaceuticals to the brain. Therefore, this review focuses on N2B delivery while giving examples of different drug delivery systems suitable for the applications. In addition, we emphasize the importance of the effective delivery of monoclonal antibodies and RNA and stress the recent literature tackling this challenge. While giving examples of nanotechnological approaches for the effective delivery of small or large molecules from the current literature, we highlight the preclinical studies and their results to prove the strategies' success and limitations.

Lactoferrin, chitosan double-coated oleosomes loaded with clobetasol propionate for remyelination in multiple sclerosis: Physicochemical characterization and in-vivo assessment in a cuprizone-induced demyelination model

Multiple sclerosis is a chronic inflammatory demyelinating disorder of the CNS characterized by continuous myelin damage accompanied by deterioration in functions. Clobetasol propionate (CP) is the most potent topical corticosteroid with serious side effects related to systemic absorption. Previous studies introduced CP for remyelination without considering systemic toxicity. This work aimed at fabrication and optimization of double coated nano-oleosomes loaded with CP to achieve brain targeting through intranasal administration. The optimized formulation was coated with lactoferrin and chitosan for the first time. The obtained double-coated oleosomes had particle size (220.07 ± 0.77 nm), zeta potential (+30.23 ± 0.41 mV) along with antioxidant capacity 9.8 μM ascorbic acid equivalents. Double coating was well visualized by TEM and significantly decreased drug release. Three different doses of CP were assessed in-vivo using cuprizone-induced demyelination in C57Bl/6 mice. Neurobehavioral tests revealed improvement in motor and cognitive functions of mice in a dose-dependent manner. Histopathological examination of the brain showed about 2.3 folds increase in corpus callosum thickness in 0.3 mg/kg CP dose. Moreover, the measured biomarkers highlighted the significant antioxidant and anti-inflammatory capacity of the formulation. In conclusion, the elaborated biopolymer-integrating nanocarrier succeeded in remyelination with 6.6 folds reduction in CP dose compared to previous studies.

A review of chitosan-based nanocarriers as drug delivery systems for brain diseases: Critical challenges, outlooks and promises

The administration of medicinal drugs orally or systemically limits the treatment of specific central nervous system (CNS) illnesses, such as certain types of brain cancers. These methods can lead to severe adverse reactions and inadequate transport of drugs to the brain, resulting in limited effectiveness. The CNS homeostasis is maintained by various barriers within the brain, such as the endothelial, epithelial, mesothelial, and glial barriers, which strictly control the movement of chemicals, solutes, and immune cells. Brain capillaries consist of endothelial cells (ECs) and perivascular pericytes, with pericytes playing a crucial role in maintaining the blood-brain barrier (BBB), influencing new blood vessel formation, and exhibiting secretory capabilities. This article summarizes the structural components and anatomical characteristics of the BBB. Intranasal administration, a non-invasive method, allows drugs to reach the brain by bypassing the BBB, while direct cerebral administration targets specific brain regions with high concentrations of therapeutic drugs. Technical and mechanical tools now exist to bypass the BBB, enabling the development of more potent and safer medications for neurological disorders. This review also covers clinical trials, formulations, challenges, and patents for a comprehensive perspective.

PLGA Nanoparticles Based Mucoadhesive Nasal In Situ Gel for Enhanced Brain Delivery of Topiramate

Oral Topiramate therapy is associated with systemic adverse effects including paresthesia,abdominal pain, and fluctuations in plasma levels. The purpose of this research was to develop an intranasal in situ gel based system comprising Topiramate polymeric nanoparticles and evaluate its potential both in vitro and in vivo. Poly (lactic-co-glycolic acid) (PLGA)nanoparticles prepared by nanoprecipitation method were added into the in situ gelling system of Poloxamer 407 and HPMC K4M. Selected formulation (TG5) was evaluated for physicochemical properties, nasal permeation and in vivo pharmacokinetics in rats. PLGAnanoparticles (O1) exhibited low particle size (~ 144.4 nm), good polydispersity index (0.202), negative zeta potential (-12.7 mV), and adequate entrapment efficiency (64.7%). Developed in situ gel showed ideal pH (6.5), good gelling time (35 s), gelling temperature(37℃), suitable viscosity (1335 cP)and drug content of 96.2%. In vitro drug release conformedto Higuchi release kinetics, exhibiting a biphasic pattern of initial burst release and sustained release for 24 h. Oral administration of the drug to Sprague-Dawley rats (G3) showed higher plasma Cmax(504 ng/ml, p < 0.0001) when compared to nasal delivery of in situ gel (G4) or solution (G5). Additionally, AUC0-α of G3 (8786.82 ng/ml*h) was considerably higher than othergroups. Brain uptake data indicates a higher drug level with G4 (112.47 ng /ml) at 12 h when compared to G3. Histopathological examination of groups; G1 (intranasal saline), G2(intranasal placebo), G3, G4, and G5 did not show any lesions of pathological significance. Overall, the experimental results observed were promising and substantiated the potential of developed in situ gel for intranasal delivery.

Tailored Borneol-Modified Lipid Nanoparticles Nasal Spray for Enhanced Nose-to-Brain Delivery to Central Nervous System Diseases

The nanodrug delivery system-based nasal spray (NDDS-NS) can bypass the blood-brain barrier and deliver drugs directly to the brain, offering unparalleled advantages in the treatment of central nervous system (CNS) diseases. However, the current design of NNDS-NS is excessively focused on mucosal absorption while neglecting the impact of nasal deposition on nose-to-brain drug delivery, resulting in an unsatisfactory nose-to-brain delivery efficiency. In this study, the effect of the dispersion medium viscosity on nasal drug deposition and nose-to-brain delivery in NDDS-NS was elucidated. The optimized formulation F5 (39.36 mPa·s) demonstrated significantly higher olfactory deposition fraction (ODF) of 23.58%, and a strong correlation between ODF and intracerebral drug delivery (R2 = 0.7755) was observed. Building upon this understanding, a borneol-modified lipid nanoparticle nasal spray (BLNP-NS) that combined both nasal deposition and mucosal absorption was designed for efficient nose-to-brain delivery. BLNP-NS exhibited an accelerated onset of action and enhanced brain targeting efficiency, which could be attributed to borneol modification facilitating the opening of tight junction channels. Furthermore, BLNP-NS showed superiority in a chronic migraine rat model. It not only provided rapid relief of migraine symptoms but also reversed neuroinflammation-induced hyperalgesia. The results revealed that borneol modification could induce the polarization of microglia, regulate the neuroinflammatory microenvironment, and repair the neuronal damage caused by neuroinflammation. This study highlights the impact of dispersion medium viscosity on the nose-to-brain delivery process of NDDS-NS and serves as a bridge between the formulation development and clinical transformation of NDDS-NS for the treatment of CNS diseases.

Carboxymethyl cellulose-based rotigotine nanocrystals-loaded hydrogel for increased transdermal delivery with alleviated skin irritation

Transdermal rotigotine (RTG) therapy is prescribed to manage Parkinson's disease (Neupro® patch). However, its use is suffered from application site reactions. Herein, drug nanocrystalline suspension (NS)-loaded hydrogel (NS-HG) employing polysaccharides simultaneously as suspending agent and hydrogel matrix was constructed for transdermal delivery, with alleviated skin irritation. RTG-loaded NS-HG was prepared using a bead-milling technique, employing sodium carboxylmethyl cellulose (Na.CMC) as nano-suspending agent (molecular weight 90,000 g/mol) and hydrogel matrix (700,000 g/mol), respectively. NS-HG was embodied as follows: drug loading: ≤100 mg/mL; shape: rectangular crystalline; crystal size: <286.7 nm; zeta potential: -61 mV; viscosity: <2.16 Pa·s; and dissolution rate: >90 % within 15 min. Nuclear magnetic resonance analysis revealed that the anionic polymers bind to RTG nanocrystals via charge interaction, affording uniform dispersion in the matrix. Rodent transdermal absorption of RTG from NS-HG was comparable to that from microemulsions, and proportional to drug loading. Moreover, NS-HG was skin-friendly; erythema and epidermal swelling were absent after repeated application. Further, NS-HG was chemically stable; >95 % of the drug was preserved up to 4 weeks under long term (25 °C/RH60%), accelerated (40 °C/RH75%), and stress (50 °C) storage conditions. Therefore, this novel cellulose derivative-based nanoformulation presents a promising approach for effective transdermal RTG delivery with improved tolerability.

Enhanced Stability and Solidification of Volatile Eugenol by Cyclodextrin-Metal Organic Framework for Nasal Powder Delivery

Eugenol (Eug) holds potential as a treatment for bacterial rhinosinusitis by nasal powder drug delivery. To stabilization and solidification of volatile Eug, herein, nasal inhalable γ-cyclodextrin metal-organic framework (γ-CD-MOF) was investigated as a carrier by gas-solid adsorption method. The results showed that the particle size of Eug loaded by γ-CD-MOF (Eug@γ-CD-MOF) distributed in the range of 10-150 μm well. In comparison to γ-CD and β-CD-MOF, γ-CD-MOF has higher thermal stability to Eug. And the intermolecular interactions between Eug and the carriers were verified by characterizations and molecular docking. Based on the bionic human nasal cavity model, Eug@γ-CD-MOF had a high deposition distribution (90.07 ± 1.58%). Compared with free Eug, the retention time Eug@γ-CD-MOF in the nasal cavity was prolonged from 5 min to 60 min. In addition, the cell viability showed that Eug@γ-CD-MOF (Eug content range 3.125-200 µg/mL) was non-cytotoxic. And the encapsulation of γ-CD-MOF could not reduce the bacteriostatic effect of Eug. Therefore, the biocompatible γ-CD-MOF could be a potential and valuable carrier for nasal drug delivery to realize solidification and nasal therapeutic effects of volatile oils.

Development of Telmisartan Nanocrystal-Based Dissolving Microneedle for Brain Targeting via Trigeminal Pathway: A Potentially Promising Treatment for Alzheimer's with an Improved Pharmacokinetic Profile

Telmisartan (TMN), an angiotensin receptor blocker (ARB) drug, is being considered as an alternative therapy for Alzheimer's disease (ALZ). However, when taken orally, its low water solubility leads to a low bioavailability and brain concentration. To overcome this problem, TMN was formulated as nanocrystals (NC), then incorporated into dissolving microneedles (DMN) to enhance drug delivery to the brain via the trigeminal route on the face. TMN-NC was formulated with 1% PVA using the top-down method and stirred for 12 h, producing the smallest particle size of 132 ± 11 nm and showing a better release profile, reaching 89.51 ± 7.52% (2 times greater than pure TMN). TMN-NC-DMN with a combination of 15% PVA and 25% PVP showed optimal mechanical strength and penetration ability; they could dissolve completely within 15 min, and their surface pH was safe for the skin. The permeation test of TMN-NC-DMN showed the highest concentration, reaching 285.80 ± 32.12 μg/mL, compared to TMN-DMN and patch control, which only reached 87.17 ± 11.24 and 94.00 ± 11.09 μg/mL, respectively. The TMN-NC-DMN combination showed better bioavailability and was found to be well-delivered to the brain without any irritation to the skin. Pharmacokinetic parameters had a significant difference (p > 0.05) compared to other preparations, making it a promising treatment for ALZ.

Research progress in brain-targeted nasal drug delivery

The unique anatomical and physiological connections between the nasal cavity and brain provide a pathway for bypassing the blood-brain barrier to allow for direct brain-targeted drug delivery through nasal administration. There are several advantages of nasal administration compared with other routes; for example, the first-pass effect that leads to the metabolism of orally administered drugs can be bypassed, and the poor compliance associated with injections can be minimized. Nasal administration can also help maximize brain-targeted drug delivery, allowing for high pharmacological activity at lower drug dosages, thereby minimizing the likelihood of adverse effects and providing a highly promising drug delivery pathway for the treatment of central nervous system diseases. The aim of this review article was to briefly describe the physiological structures of the nasal cavity and brain, the pathways through which drugs can enter the brain through the nose, the factors affecting brain-targeted nasal drug delivery, methods to improve brain-targeted nasal drug delivery systems through the application of related biomaterials, common experimental methods used in intranasal drug delivery research, and the current limitations of such approaches, providing a solid foundation for further in-depth research on intranasal brain-targeted drug delivery systems (see Graphical Abstract).

Rivastigmine-DHA ion-pair complex improved loading in hybrid nanoparticles for better amyloid inhibition and nose-to-brain targeting in Alzheimer's

Rivastigmine hydrogen tartrate (RIV-HT) is given orally for Alzheimer's disease. However, oral therapy shows low brain bioavailability, short half-life and gastrointestinal-mediated adverse effects. RIV-HT intranasal delivery can avoid these side effects, but its low brain bioavailability remains challenging. These issues could be solved with hybrid lipid nanoparticles with enough drug loading to enhance RIV-HT brain bioavailability while avoiding oral route side effects. The RIV-HT and docosahexaenoic acid (DHA) ion-pair complex (RIV:DHA) was prepared to improve drug loading into lipid-polymer hybrid (LPH) nanoparticles. Two types of LPH, i.e., cationic (RIV:DHA LPH(+ve)) and anionic LPH (RIV:DHA LPH(-ve)) were developed. The effect of LPH surface charge on in-vitro amyloid inhibition, in-vivo brain concentrations and nose-to-brain drug targeting efficiency were investigated. LPH nanoparticles showed concentration dependant amyloid inhibition. RIV:DHA LPH(+ve) demonstrated relatively enhanced Aβ1-42 peptide inhibition. The thermoresponsive gel embedded with LPH nanoparticles improved nasal drug retention. LPH nanoparticles gel significantly improved pharmacokinetic parameters compared to RIV-HT gel. RIV:DHA LPH(+ve) gel showed better brain concentrations than RIV:DHA LPH(-ve) gel. The histological examination of nasal mucosa treated with LPH nanoparticles gel showed that the delivery system was safe. In conclusion, the LPH nanoparticle gel was safe and efficient in improving the nose-to-brain targeting of RIV, which can potentially be utilized in managing Alzheimer's.