Biopolymer Nanoparticles for Nose-to-Brain Drug Delivery: A New Promising Approach for the Treatment of Neurological Diseases

Intranasal delivery of glucagon-like peptide-1 to the brain for obesity treatment: opportunities and challenges

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs), approved by the US FDA for obesity treatment, are typically administered subcutaneously, an invasive method leading to suboptimal patient adherence and peripheral side effects. Additionally, this route requires the drug to cross the restrictive blood-brain barrier (BBB), limiting its safety and effectiveness in weight management and cognitive addiction disorders. Delivering the drug intranasally could overcome these drawbacks.

AREAS COVERED

This review summarizes GLP-1 RAs used as anti-obesity agents, focusing on the intranasal route as a potential pathway to deliver these biomolecules to the brain. It also discusses strategies to overcome challenges associated with nasal delivery.

EXPERT OPINION

Nose-to-brain (N2B) pathways can address limitations of the subcutaneous route for GLP-1 RAs. However, peptide delivery to the brain is challenging due to nasal physiological barriers and the drug's physicochemical properties. Innovative approaches, such as cell permeation enhancers, mucoadhesive systems, and nanocarriers in nasal formulations, along with efficient drug delivery devices, show promising preclinical results. Despite this, successful preclinical data does not guarantee clinical effectiveness, highlighting the need for comprehensive clinical investigations to optimize formulations and fully utilize the nose-to-brain interface for peptide delivery.

Synthesis and characterization of nano-biopolymer carriers loaded with clove (Syzygium aromaticum L.) extract as an anticancer agent: an in vitro study

The objective of this work was to design a new drug nanoparticle (NP) composed of chitosan/β-cyclodextrin/sodium tripolyphosphate/alginate (CS/βCD/TPP/AL) loaded with a clove extract (CE) for potential anticancer effects. The extract was prepared by two extraction methods: hydroalcoholic maceration (MAC) with 80% MeOH and supercritical fluid (SCF). The MACCE and SCFCE CE NPs had particle sizes of 71 nm and 20 nm, respectively with irregular spherical shapes. The nanocarriers achieved entrapment efficiencies of over 90%. MACCE-NPs and SCFCE-NPs released 18.35% and 10.12% of the extract after 6 h, respectively. Cell viability decreased to 54%, 7%, and 12% in HeLa, U87, and KB cell lines, respectively, after a 48-hour treatment with SCFCE-NPs and 75%, 8%, and 17% after treatment with MACCE-NPs, significantly reduced compared to the control. It is concluded that NPs containing CE exhibit a higher degree of toxicity due to better penetration into cells.

Emerging Perspectives on Prime Editor Delivery to the Brain

Prime editing shows potential as a precision genome editing technology, as well as the potential to advance the development of next-generation nanomedicine for addressing neurological disorders. However, turning in prime editors (PEs), which are macromolecular complexes composed of CRISPR/Cas9 nickase fused with a reverse transcriptase and a prime editing guide RNA (pegRNA), to the brain remains a considerable challenge due to physiological obstacles, including the blood-brain barrier (BBB). This review article offers an up-to-date overview and perspective on the latest technologies and strategies for the precision delivery of PEs to the brain and passage through blood barriers. Furthermore, it delves into the scientific significance and possible therapeutic applications of prime editing in conditions related to neurological diseases. It is targeted at clinicians and clinical researchers working on advancing precision nanomedicine for neuropathologies.

Neuroprotective and anti-inflammatory effects of curcumin in Alzheimer's disease: Targeting neuroinflammation strategies

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-beta plaques and neurofibrillary tangles, leading to neuronal loss. Curcumin, a polyphenolic compound derived from Curcuma longa, has shown potential neuroprotective effects due to its anti-inflammatory and antioxidant properties. This review aims to synthesize current preclinical data on the anti-neuroinflammatory mechanisms of curcumin in the context of AD, addressing its pharmacokinetics, bioavailability, and potential as a therapeutic adjunct. An exhaustive literature search was conducted, focusing on recent studies within the last 10 years related to curcumin's impact on neuroinflammation and its neuroprotective role in AD. The review methodology included sourcing articles from specialized databases using specific medical subject headings terms to ensure precision and relevance. Curcumin demonstrates significant neuroprotective properties by modulating neuroinflammatory pathways, scavenging reactive oxygen species, and inhibiting the production of pro-inflammatory cytokines. Despite its potential, challenges remain regarding its limited bioavailability and the scarcity of comprehensive human clinical trials. Curcumin emerges as a promising therapeutic adjunct in AD due to its multimodal neuroprotective benefits. However, further research is required to overcome challenges related to bioavailability and to establish effective dosing regimens in human subjects. Developing novel delivery systems and formulations may enhance curcumin's therapeutic potential in AD treatment.

Nasal Delivery to the Brain: Harnessing Nanoparticles for Effective Drug Transport

The nose-to-brain drug-delivery system has emerged as a promising strategy to overcome the challenges associated with conventional drug administration for central nervous system disorders. This emerging field is driven by the anatomical advantages of the nasal route, enabling the direct transport of drugs from the nasal cavity to the brain, thereby circumventing the blood-brain barrier. This review highlights the significance of the anatomical features of the nasal cavity, emphasizing its high permeability and rich blood supply that facilitate rapid drug absorption and onset of action, rendering it a promising domain for neurological therapeutics. Exploring recent developments and innovations in different nanocarriers such as liposomes, polymeric nanoparticles, solid lipid nanoparticles, dendrimers, micelles, nanoemulsions, nanosuspensions, carbon nanotubes, mesoporous silica nanoparticles, and nanogels unveils their diverse functions in improving drug-delivery efficiency and targeting specificity within this system. To minimize the potential risk of nanoparticle-induced toxicity in the nasal mucosa, this article also delves into the latest advancements in the formulation strategies commonly involving surface modifications, incorporating cutting-edge materials, the adjustment of particle properties, and the development of novel formulations to improve drug stability, release kinetics, and targeting specificity. These approaches aim to enhance drug absorption while minimizing adverse effects. These strategies hold the potential to catalyze the advancement of safer and more efficient nose-to-brain drug-delivery systems, consequently revolutionizing treatments for neurological disorders. This review provides a valuable resource for researchers, clinicians, and pharmaceutical-industry professionals seeking to advance the development of effective and safe therapies for central nervous system disorders.

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).

Overcoming challenges in glioblastoma treatment: targeting infiltrating cancer cells and harnessing the tumor microenvironment

Glioblastoma (GB) is a highly malignant primary brain tumor with limited treatment options and poor prognosis. Despite current treatment approaches, including surgical resection, radiation therapy, and chemotherapy with temozolomide (TMZ), GB remains mostly incurable due to its invasive growth pattern, limited drug penetration beyond the blood-brain barrier (BBB), and resistance to conventional therapies. One of the main challenges in GB treatment is effectively eliminating infiltrating cancer cells that remain in the brain parenchyma after primary tumor resection. We've reviewed the most recent challenges and surveyed the potential strategies aimed at enhancing local treatment outcomes.

Nanoparticles Mediated the Diagnosis and Therapy of Glioblastoma: Bypass or Cross the Blood-Brain Barrier

Glioblastoma is one of the most aggressive central nervous system malignancies with high morbidity and mortality. Current clinical approaches, including surgical resection, radiotherapy, and chemotherapy, are limited by the difficulty of targeting brain lesions accurately, leading to disease recurrence and fatal outcomes. The lack of effective treatments has prompted researchers to continuously explore novel therapeutic strategies. In recent years, nanomedicine has made remarkable progress and expanded its application in brain drug delivery, providing a new treatment for brain tumors. Against this background, this article reviews the application and progress of nanomedicine delivery systems in brain tumors. In this paper, the mechanism of nanomaterials crossing the blood-brain barrier is summarized. Furthermore, the specific application of nanotechnology in glioblastoma is discussed in depth.

Emerging strategies to fabricate polymeric nanocarriers for enhanced drug delivery across blood-brain barrier: An overview

Blood-brain barrier (BBB) serves as an essential interface between central nervous system (CNS) and its periphery, allowing selective permeation of ions, gaseous molecules, and other nutrients to maintain metabolic functions of brain. Concurrently, it restricts passage of unsolicited materials from bloodstream to CNS which could otherwise lead to neurotoxicity. Nevertheless, in the treatment of neurodegenerative diseases such as Parkinson's, Alzheimer's, diffuse intrinsic pontine glioma, and other brain cancers, drugs must reach CNS. Among various materials developed for this purpose, a few judiciously selected polymeric nanocarriers are reported to be highly prospective to facilitate BBB permeation. However, the challenge of transporting drug-loaded nanomaterials across this barrier remains formidable. Herein a concise analysis of recently employed strategies for designing polymeric nanocarriers to deliver therapeutics across BBB is presented. Impacts of 3Ss, namely, size, shape, and surface charge of polymeric nanocarriers on BBB permeation along with different ligands used for nanoparticle surface modification to achieve targeted delivery have been scrutinized. Finally, we elucidated future research directions in the context of designing smart polymeric nanocarriers for BBB permeation. This work aims to guide researchers engaged in polymeric nanocarrier design, helping them navigate where to begin, what challenges to address, and how to proceed effectively.

The Role of Ear, Nose, and Throat Specialists in the Nose-to-Brain Pathway

This Viewpoint discusses the role of ear, nose, and throat specialists in the understanding, development, growth, and administration of direct nose-to-brain delivery route devices and therapies.

The Potential of the Nose-to-Brain Delivery of PACAP for the Treatment of Neuronal Disease

Research on the neuroprotective effect of pituitary adenylate cyclase-activating polypeptide (PACAP) and its use as a therapeutic agent has grown over the past 30 years. Both in vitro and in vivo experiments have shown that PACAP exerts a strong neuroprotective effect in many central and peripheral neuronal diseases. Various delivery routes have been employed from intravenous (IV) injections to intracerebroventricular (ICV) administration, leading either to systemic or topical delivery of the peptide. Over the last decade, a growing interest in the use of intranasal (IN) administration of PACAP and other therapeutic agents has emerged as an alternative delivery route to target the brain. The aim of this review is to summarize the findings on the neuroprotective effect of PACAP and to discuss how the IN administration of PACAP could contribute to target the effects of this pleiotropic peptide.

Paclitaxel Delivery to the Brain for Glioblastoma Treatment

The development of paclitaxel-loaded polymeric nanoparticles for the treatment of brain tumors was investigated. Poly(lactide-glycolide) (PLGA) nanoparticles containing 10% w/w paclitaxel with a particle size of 216 nm were administered through intranasal and intravenous routes to male Sprague-Dawley rats at a dose of 5 mg/kg. Both routes of administration showed appreciable accumulation of paclitaxel in brain tissue, liver, and kidney without any sign of toxicity. The anti-proliferative effect of the nanoparticles on glioblastoma tumor cells was comparable to that of free paclitaxel.

Nose to brain delivery of naringin-loaded chitosan nanoparticles for potential use in oxaliplatin-induced chemobrain in rats: impact on oxidative stress, cGAS/STING and HMGB1/RAGE/TLR2/MYD88 inflammatory axes

OBJECTIVES

Oxaliplatin induces chemobrain in cancer patients/survivors. Nutraceutical naringin has antioxidant and anti-inflammatory properties with low oral bioavailability. Our aim was to formulate naringin in chitosan nanoparticles for nose to brain delivery and assess its neuroprotective effect against oxaliplatin-induced chemobrain in rats.

METHODS

Naringin chitosan nanoparticles were prepared by ionic gelation. Rats were administered oral naringin (80 mg/kg), intranasal naringin (0.3 mg/kg) or intranasal naringin-loaded chitosan nanoparticles (0.3 mg/kg). Naringin's neuroprotective efficacy was assessed based on behavioral tests, histopathology, and measuring oxidative stress and inflammatory markers.

RESULTS

Selected nanoparticles formulation showed drug loading of 5%, size of 150 nm and were cationic. Intranasal naringin administration enhanced memory function, inhibited hippocampal acetylcholinesterase activity, and corrected oxaliplatin-induced histological changes. Moreover, it reduced malondialdehyde and elevated reduced glutathione hippocampal levels. Furthermore, it decreased levels of inflammatory markers: NF-kB and TNF-α by 1.25-fold. Upstream to this inflammatory status, intranasal naringin downregulated the hippocampal protein levels of two pathways: cGAS/STING and HMGB1/RAGE/TLR2/MYD88.

CONCLUSION

Intranasal naringin-loaded chitosan nanoparticles showed superior amelioration of oxaliplatin-induced chemobrain in rats at a dose 267-fold lower to that administered orally. The potential involvement of cGAS/STING and HMGB1/RAGE/TLR2/MYD88 pathways in the mechanistic process of either oxaliplatin-induced chemobrain or naringin-mediated neuroprotection was evidenced.

A Dual Therapy of Nanostructured Lipid Carrier Loaded with Teriflunomide-A Dihydro-Orotate Dehydrogenase Inhibitor and an miR-155-Antagomir in Cuprizone-Induced C57BL/6J Mouse

The effective treatment of central nervous system (CNS) disorders such as multiple sclerosis (MS) has been challenging due to the limited ability of therapeutic agents to cross the blood-brain barrier (BBB). In this study, we investigated the potential of nanocarrier systems to deliver miR-155-antagomir-teriflunomide (TEF) dual therapy to the brain via intranasal (IN) administration to manage MS-associated neurodegeneration and demyelination. Our results showed that the combinatorial therapy of miR-155-antagomir and TEF loaded in nanostructured lipid carriers (NLCs) significantly increased brain concentration and improved targeting potential. The novelty of this study lies in the use of a combinatorial therapy approach of miR-155-antagomir and TEF loaded in NLCs. This is a significant finding, as the effective delivery of therapeutic molecules to the CNS has been a challenge in treating neurodegenerative disorders. Additionally, this study sheds light on the potential use of RNA-targeting therapies in personalized medicine, which could revolutionize the way CNS disorders are managed. Furthermore, our findings suggest that nanocarrier-loaded therapeutic agents have great potential for safe and economical delivery in treating CNS disorders. Our study provides novel insights into the effective delivery of therapeutic molecules via the IN route for managing neurodegenerative disorders. In particular, our results demonstrate the potential of delivering miRNA and TEF via the intranasal route using the NLC system. We also demonstrate that the long-term use of RNA-targeting therapies could be a promising tool in personalized medicine. Importantly, using a cuprizone-induced animal model, our study also investigated the effects of TEF-miR155-antagomir-loaded NLCs on demyelination and axonal damage. Following six weeks of treatment, the TEF-miR155-antagomir-loaded NLCs potentially lowered the demyelination and enhanced the bioavailability of the loaded therapeutic molecules. Our study is a paradigm shift in delivering miRNAs and TEF via the intranasal route and highlights the potential of this approach for managing neurodegenerative disorders. In conclusion, our study provides critical insights into the effective delivery of therapeutic molecules via the IN route for managing CNS disorders, and especially MS. Our findings have significant implications for the future development of nanocarrier-based therapies and personalized medicine. Our results provide a strong foundation for further studies and the potential to develop safe and economic therapeutics for CNS disorders.

Crosslinked Chitosan Nanoparticles with Muco-Adhesive Potential for Intranasal Delivery Applications

Intranasal drug delivery is convenient and provides a high bioavailability but requires the use of mucoadhesive nanocarriers. Chitosan is a well-established polymer for mucoadhesive applications but can suffer from poor cytocompatibility and stability upon administration. In this work, we present a method to obtain stable and cytocompatible crosslinked chitosan nanoparticles. We used 2,6-pyridinedicarboxylic acid as a biocompatible crosslinker and compared the obtained particles with those prepared by ionotropic gelation using sodium tripolyphosphate. Nanoparticles were tested to evaluate the size and the surface charge, as well as their stability in storage conditions (4 °C), at the nasal cavity temperature (32 °C), and at the body temperature (37 °C). The crosslinked chitosan nanoparticles showed a size around 150 nm and a surface charge of 10.3 mV ± 0.9 mV, both compatible with the intranasal drug administration. Size and surface charge parameters did not significantly vary over time, indicating the good stability of these nanoparticles. We finally tested their cytocompatibility in vitro using SHSY5Y human neuroblastoma and RPMI 2650 human nasal epithelial cells, with positive results. In conclusion, the proposed synthetic system shows an interesting potential as a drug carrier for intranasal delivery.

Progress of Electrospun Nanofibrous Carriers for Modifications to Drug Release Profiles

Electrospinning is an advanced technology for the preparation of drug-carrying nanofibers that has demonstrated great advantages in the biomedical field. Electrospun nanofiber membranes are widely used in the field of drug administration due to their advantages such as their large specific surface area and similarity to the extracellular matrix. Different electrospinning technologies can be used to prepare nanofibers of different structures, such as those with a monolithic structure, a core-shell structure, a Janus structure, or a porous structure. It is also possible to prepare nanofibers with different controlled-release functions, such as sustained release, delayed release, biphasic release, and targeted release. This paper elaborates on the preparation of drug-loaded nanofibers using various electrospinning technologies and concludes the mechanisms behind the controlled release of drugs.

Systemic and brain delivery of antidiabetic peptides through nasal administration using cell-penetrating peptides

The intranasal route has emerged as a promising strategy that can direct delivery of drugs into the systemic circulation because the high-vascularized nasal cavity, among other advantages, avoids the hepatic first-pass metabolism. The nose-to-brain pathway provides a non-invasive alternative to other routes for the delivery of macromolecular therapeutics. A great variety of methodologies has been developed to enhance the efficiency of transepithelial translocation of macromolecules. Among these, the use of cell-penetrating peptides (CPPs), short protein transduction domains (PTDs) that facilitate the intracellular transport of various bioactive molecules, has become an area of extensive research in the intranasal delivery of peptides and proteins either to systemic or to brain compartments. Some CPPs have been applied for the delivery of peptide antidiabetics, including insulin and exendin-4, for treating diabetes and Alzheimer's disease. This review highlights the current status of CPP-driven intranasal delivery of peptide drugs and its potential applicability as a universal vehicle in the nasal drug delivery.