Strategies for brain-targeting liposomal delivery of small hydrophobic molecules in the treatment of neurodegenerative diseases

Harnessing curcumin and nanotechnology for enhanced treatment of breast cancer bone metastasis

Breast cancer (BC) bone metastasis poses a significant clinical challenge due to its impact on patient prognosis and quality of life. Curcumin (CUR), a natural polyphenol compound found in turmeric, has shown potential in cancer therapy due to its anti-inflammatory, antioxidant, and anticancer properties. However, its metabolic instability and hydrophobicity have hindered its clinical applications, leading to a short plasma half-life, poor absorption, and low bioavailability. To enhance the drug-like properties of CUR, nanotechnology-based delivery strategies have been employed, utilizing polymeric, lipidic, and inorganic nanoparticles (NPs). These approaches have effectively overcome CUR's inherent limitations by enhancing its stability and cellular bioavailability both in vitro and in vivo. Moreover, targeting molecules with high selectivity towards bone metastasized breast cancer cells can be used for site specific delivery of curcumin. Alendronate (ALN), a bone-seeking bisphosphonate, is one such moiety with high selectivity towards bone and thus can be effectively used for targeted delivery of curcumin loaded nanocarriers. This review will detail the process of bone metastasis in BC, elucidate the mechanism of action of CUR, and assess the efficacy of nanotechnology-based strategies for CUR delivery. Specifically, it will focus on how these strategies enhance CUR's stability and improve targeted delivery approaches in the treatment of BC bone metastasis.

Construction Strategy of Functionalized Liposomes and Multidimensional Application

Liposomes are widely used in the biological field due to their good biocompatibility and surface modification properties. With the development of biochemistry and material science, many liposome structures and their surface functional components have been modified and optimized one by one, pushing the liposome platform from traditional to functionalized and intelligent, which will better satisfy and expand the needs of scientific research. However, a main limiting factor effecting the efficiency of liposomes is the complicated environmental conditions in the living body. Currently, in order to overcome the above problem, functionalized liposomes have become a very promising strategy. In this paper, binding strategies of liposomes with four main functional elements, namely nucleic acids, antibodies, peptides, and stimuli-responsive motif have been summarized for the first time. In addition, based on the construction characteristics of functionalized liposomes, such as drug-carrying, targeting, long-circulating, and stimulus-responsive properties, a comprehensive overview of their features and respective research progress are presented. Finally, the paper critically presents the limitations of these functionalized liposomes in the current applications and also prospectively suggests the future development directions, aiming to accelerate realization of their industrialization.

MicroRNA-195 liposomes for therapy of Alzheimer's disease

The complex etiologies and mechanisms of Alzheimer's disease (AD) underscore the importance for devising multitarget drugs to achieve effective therapy. MicroRNAs (miRNAs) are capable of concurrently regulating the expression of multiple proteins by selectively targeting disease- associated genes in a sequence-specific fashion. Nonetheless, as RNA-based drugs, their stability in the circulation and capacity of traversing the blood-brain barrier (BBB) is largely compromised, thereby limiting their potential clinical applications. In this study, we formulated the nanoliposomes encapsulating polyethyleneimine (PEI)/miR-195 complex (DPMT@PEI/miR-195) that was engineered through dual modifications to contain P-aminophenyl-alpha-d-mannopyranoside (MAN) and cationic cell-penetrating peptide (TAT). DPMT@PEI/miR-195 exhibited the enhanced BBB- and cell membrane penetrating capability. As expected, we observed that DPMT@PEI/miR-195 administered through intravenous tail injection of produced greater effectiveness than donepezil and the same range of effect as aducanumab in alleviating the cognitive decline in 7-month-old APP/PS1 mice. Moreover, the combination treatment with DPMT@PEI/miR-195 and donepezil effectively ameliorated the deterioration of cognition in 16-month-old APP/PS1 mice, with enhanced effects than either DPMT@PEI/miR-195 or donepezil alone. Furthermore, DPMT@PEI/miR-195 effectively attenuated the positive signals of Aβ, AT8, and CD68 in APP/PS1 mice without notable side effects. Our findings indicate DPMT@PEI/miR-195 as a promising potentially new agent or approach for the prophylaxis and treatment of early and advanced stages of Alzheimer's disease.

Neuroprotective effect of quercetin nanoparticles: A possible prophylactic effect in cerebellar neurodegenerative disorders

Memory deficit, anxiety, coordination deficit and depression are common neurological disorders attributed to aluminum (Al) buildup in the nervous system. Quercetin nanoparticles (QNPs) are a newly developed effective neuroprotectant. We aimed to investigate the potential protective and therapeutic effects of QNPs in Al induced toxicity in rat cerebellum. A rat model of Al-induced cerebellar damage was created by AlCl3 (100 mg/kg) administration orally for 42 days. QNPs (30 mg/kg) was administered for 42-days as a prophylactic (along with AlCl3 administration) or therapeutic for 42-days (following AlCl3 induced cerebellar damage). Cerebellar tissues were assessed for structural and molecular changes. The results showed that Al induced profound cerebellar structural and molecular changes, including neuronal damage, astrogliosis and tyrosine hydroxylase downregulation. Prophylactic QNPs significantly reduced Al induced cerebellar neuronal degeneration. QNPs is a promising neuroprotectant that can be used in elderly and vulnerable subjects to protect against neurological deterioration. It could be a promising new line for therapeutic intervention in neurodegenerative diseases.

Use of Liposome-encapsulated estetrol for treatment of Neonatal Hypoxic-Ischemic encephalopathy

Estetrol (E4) is a natural estrogen synthesized only during pregnancy. It has strong neuroprotective and antioxidative activities. The aim of the present study was to define the neuroprotective potency of E4 encapsulated either in liposome (Lipo-E4) or in drug-in cyclodextrin (HP-β-CD) in liposome (DCL) system, and compare them with a single use of E4. In vitro studies were performed in an oxidative stress model of primary hippocampal neuronal cell cultures, followed by the lactate dehydrogenase activity and cell proliferation assays. In vivo studies were conducted by using a model of neonatal hypoxic-ischemic encephalopathy in immature rat pups. Brain samples were studied by (immuno)histochemistry for the detection of survived cells, expression of microtubule-associated protein-2, myelin basic protein, doublecortin and vascular-endothelial growth factor. Concentrations of glial fibrillary acidic protein in blood serum were studied by ELISA. In vitro, cell proliferation was significantly up-regulated in cultures treated either by DCL-E4 or E4 compared to the control cells, whereas DCL-E4 treated cells had significantly higher survival rate than the cells treated by E4 alone. Evaluation of brain samples showed that DCL-E4 and a high dose of E4 alone significantly preserve the grey and the white matter loses, and diminish GFAP expression in blood. Although DCL-E4 and E4 have similar effect on neurogenesis in the hippocampus and the cortex, DCL-E4 treatment significantly up-regulates angiogenesis in the hippocampus compared to a single use of E4. Present work reveals for the first time that liposome-encapsulated E4 might be a better alternative to a single use of E4.

Strategic nanocarriers to control neurodegenerative disorders: Concept, challenges, and future perspective

Various neurodegenerative diseases (parkinson, huntington, alzheimer, and amyotrophic lateral sclerosis) are becoming serious global health challenges. Despite various treatment options, successful delivery and effective outcomes have been challenged with several physiological-anatomical barriers, formulation related issues, post-administration hurdles, regulatory constraints, physical hurdles, environmental issues, and safety concern. In the present review, we addressed a brief understanding of pathological and normal condition of blood brain barrier (BBB), rational for brain delivery using nanocarriers, major challenges, advantages of nanomedicine, critical aspects of nanomedicine to translate from bed to clinics, and strategic approaches for improved delivery across BBB. The review addressed various mechanistic perspective for delivery of drug loaded nanocarriers across BBB. Moreover, several reports have been published wherein phytomedicine, exosomes, magnetic nanopartilces, functionalized nanocarriers, cationic nanopartilces, and nano-phytomedicine were investigated for remarkable improvement in neurological disorders. These findings are informative for healthcare professionals, researchers, and scientists working in the domains. The successful application and convincing outcomes of nanomedicines were envisaged with clinical trials conducted on various drugs intended to control neurological disorders (NDs). Conclusively, the review addressed comprehensive findings on various aspects of drug loaded nanocarrier delivery across BBB, considerable risks, potential therapeutic benefits, clinical trial based outcomes, and recent advances followed by future perspectives.

Parenteral Lipid-Based Nanoparticles for CNS Disorders: Integrating Various Facets of Preclinical Evaluation towards More Effective Clinical Translation

Contemporary trends in combinatorial chemistry and the design of pharmaceuticals targeting brain disorders have favored the development of drug candidates with increased lipophilicity and poorer water solubility, with the expected improvement in delivery across the blood-brain barrier (BBB). The growing availability of innovative excipients/ligands allowing improved brain targeting and controlled drug release makes the lipid nanocarriers a reasonable choice to overcome the factors impeding drug delivery through the BBB. However, a wide variety of methods, study designs and experimental conditions utilized in the literature hinder their systematic comparison, and thus slows the advances in brain-targeting by lipid-based nanoparticles. This review provides an overview of the methods most commonly utilized during the preclinical testing of liposomes, nanoemulsions, solid lipid nanoparticles and nanostructured lipid carriers intended for the treatment of various CNS disorders via the parenteral route. In order to fully elucidate the structure, stability, safety profiles, biodistribution, metabolism, pharmacokinetics and immunological effects of such lipid-based nanoparticles, a transdisciplinary approach to preclinical characterization is mandatory, covering a comprehensive set of physical, chemical, in vitro and in vivo biological testing.

Efficacy of Polymer-Based Nanomedicine for the Treatment of Brain Cancer

Malignant brain tumor is a life-threatening disease with a low survival rate. The therapies available for the treatment of brain tumor is limited by poor uptake via the blood-brain barrier. The challenges with the chemotherapeutics used for the treatment of brain tumors are poor distribution, drug toxicity, and their inability to pass via the blood-brain barrier, etc. Several researchers have investigated the potential of nanomedicines for the treatment of brain cancer. Nanomedicines are designed with nanosize particle sizes with a large surface area and are loaded with bioactive agents via encapsulation, immersion, conjugation, etc. Some nanomedicines have been approved for clinical use. The most crucial part of nanomedicine is that they promote drug delivery across the blood-brain barrier, display excellent specificity, reduce drug toxicity, enhance drug bioavailability, and promote targeted drug release mechanisms. The aforementioned features make them promising therapeutics for brain targeting. This review reports the in vitro and in vivo results of nanomedicines designed for the treatment of brain cancers.

Pathogenic mechanisms and therapeutic promise of phytochemicals and nanocarriers based drug delivery against radiotherapy-induced neurotoxic manifestations

Radiotherapy is one of the extensively used therapeutic modalities in glioblastoma and other types of cancers. Radiotherapy is either used as a first-line approach or combined with pharmacotherapy or surgery to manage and treat cancer. Although the use of radiotherapy significantly increased the survival time of patients, but its use has been reported with marked neuroinflammation and cognitive dysfunction that eventually reduced the quality of life of patients. Based on the preclinical and clinical investigations, the profound role of increased oxidative stress, nuclear translocation of NF-kB, production of proinflammatory cytokines such as TNF-α, IL-6, IL-β, increased level of MMPs, increased apoptosis, reduced angiogenesis, neurogenesis, and histological aberrations in CA1, CA2, CA3 and DG region of the hippocampus have been reported. Various pharmacotherapeutic drugs are being used as an adjuvant to counteract this neurotoxic manifestation. Still, most of these drugs suffer from systemic adverse effect, causes interference to ongoing chemotherapy, and exhibit pharmacokinetic limitations in crossing the blood-brain barrier. Therefore, various phytoconstituents, their nano carrier-based drug delivery systems and miRNAs have been explored to overcome the aforementioned limitations. The present review is focused on the mechanism and evidence of radiotherapy-induced neuroinflammation and cognitive dysfunction, pathological and molecular changes in the brain homeostasis, available adjuvants, their limitations. Additionally, the potential role and mechanism of neuroprotection of various nanocarrier based natural products and miRNAs have been discussed.

Correlation between in vivo microdialysis pharmacokinetics and ex vivo permeation for sinomenine hydrochloride transfersomes with enhanced skin absorption

Transdermal drug delivery systems have drawn increasing attention in recent decades. Estimation of the correlation between ex vivo permeation and in vivo absorption (EVIVC) is an indispensable issue in the research and development of transdermal pharmaceutical products. In this paper, sinomenine hydrochloride (SH) transfersomes (SHTs) were prepared with sodium deoxycholate as edge activator, while SH liposomes (SHLs) were prepared as a control preparation. The transdermal permeation characteristics differences between them were explored by an ex vivo skin permeation experiment with Franz diffusion cell and an in vivo skin/blood pharmacokinetic experiment facilitated by double-sited microdialysis sampling technique. The curves of percentage absorbed versus time (absorption curves) under the skin and in the blood were plotted according to the percentages calculated by the deconvolution approach with the application of Wagner-Nelson model, and were correlated with the ex vivo permeation curves to evaluate a level A correlation, while a level C correlation evaluation was conducted based on the in vivo steady-state blood concentration (C_ss) and the ex vivo steady-state transdermal permeation rate. The ex vivo permeation test indicated that the cumulative transdermal permeated amount of SH at 36 h in SHTs was about 1.7 times of that in SHLs. The skin pharmacokinetic data showed that the C_ss and AUC_0-t of SHTs were about 8.8 and 8.0 times of those of SHLs, respectively, and the MRT_0-t of SHTs was shorter. The blood pharmacokinetic data showed that the C_ss and AUC_0-t of SHTs were about 3.7 and 2.9 times of those of SHLs, respectively. The in vivo absorption curves were correlated well with the ex vivo permeation curves. The squares of correlation coefficient (R²) for SHTs and SHLs were 0.9153 and 0.9355 respectively in the skin, were 0.8536 and 0.7747 respectively in the blood. As to level C EVIVC, there was no significant difference between the predicted C_ss from ex vivo and the measured C_ssin vivo. The transfersomes can be employed as effective vehicles to promote the transdermal absorption of SH, and it is feasible to predict the in vivo skin/blood pharmacokinetic properties of SHLs and SHTs based on the ex vivo skin permeation characteristics.

Nanoparticles for drug delivery in Parkinson's disease

Although effective symptomatic treatments for Parkinson's disease (PD) have been available for some time, efficient and well-controlled drug delivery to the brain has proven to be challenging. The emergence of nanotechnology has created new opportunities not only for improving the pharmacokinetics of conventional therapies but also for developing novel treatment approaches and disease modifying therapies. Several exciting strategies including drug carrier nanoparticles targeting specific intracellular pathways and structural reconformation of tangled proteins as well as introducing reprogramming genes have already shown promise and are likely to deliver more tailored approaches to the treatment of PD in the future. This paper reviews the role of nanoparticles in PD including a discussion of both their composition and functional capacity as well as their potential to deliver better therapeutic agents.

The Role of Natural Compounds and their Nanocarriers in the Treatment of CNS Inflammation

Neuroinflammation, which is involved in various inflammatory cascades in nervous tissues, can result in persistent and chronic apoptotic neuronal cell death and programmed cell death, triggering various degenerative disorders of the central nervous system (CNS). The neuroprotective effects of natural compounds against neuroinflammation are mainly mediated by their antioxidant, anti-inflammatory, and antiapoptotic properties that specifically promote or inhibit various molecular signal transduction pathways. However, natural compounds have several limitations, such as their pharmacokinetic properties and stability, which hinder their clinical development and use as medicines. This review discusses the molecular mechanisms of neuroinflammation and degenerative diseases of CNS. In addition, it emphasizes potential natural compounds and their promising nanocarriers for overcoming their limitations in the treatment of neuroinflammation. Moreover, recent promising CNS inflammation-targeted nanocarrier systems implementing lesion site-specific active targeting strategies for CNS inflammation are also discussed.

Blood-Brain Barrier: More Contributor to Disruption of Central Nervous System Homeostasis Than Victim in Neurological Disorders

The blood-brain barrier (BBB) is a dynamic but solid shield in the cerebral microvascular system. It plays a pivotal role in maintaining central nervous system (CNS) homeostasis by regulating the exchange of materials between the circulation and the brain and protects the neural tissue from neurotoxic components as well as pathogens. Here, we discuss the development of the BBB in physiological conditions and then focus on the role of the BBB in cerebrovascular disease, including acute ischemic stroke and intracerebral hemorrhage, and neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). Finally, we summarize recent advancements in the development of therapies targeting the BBB and outline future directions and outstanding questions in the field. We propose that BBB dysfunction not only results from, but is causal in the pathogenesis of neurological disorders; the BBB is more a contributor to the disruption of CNS homeostasis than a victim in neurological disorders.

The role of antibody delivery formation in cancer therapy

Cancer has become one of the major threats to human survival. Because of antibodies specificity and low toxicity, it is the primary choice to diagnose and treat cancer. It is easy to be cleared from the blood circulation or distributing throughout the body and causes unnecessary side effects. It is necessary to delivery antibodies to the tumour region in a stable, safe and effective manner. In this review, we discuss the latest studies that aimed to delivery antibodies to tumour sites via several vector forms, such as liposomes, carbon nanomaterials, and gold nanomaterials. How to deliver antibodies to the target site is a difficulty for antibody therapy. This review summarises the antibody's therapeutic forms and carrier materials in recent years, and to explore how antibodies can be safely and stably delivered to the target site.