Dual functional liposomes carrying antioxidants against tau hyperphosphorylation and apoptosis of neurons

Dual-targeting liposomes modified with BTP-7 and pHA for combined delivery of TCPP and TMZ to enhance the anti-tumour effect in glioblastoma cells

AIM

To construct a novel nano-carrier with dual ligands to achieve superior anti-tumour efficacy and lower toxic side effects.

METHODS

Liposomes were prepared by thin film hydration method. Ultraviolet, high performance liquid chromatography, nano-size analyser, ultrafiltration centrifugation, dialysis, transmission electron microscope, flow cytometry, Cell Counting Kit-8, confocal laser scanning microscopy, transwell, and tumorsphere assay were used to study the characterisations, cytotoxicity, and in vitro targeting of dg-Bcan targeting peptide (BTP-7)/pHA-temozolomide (TMZ)/tetra(4-carboxyphenyl)porphyrin (TCPP)-Lip.

RESULTS

BTP-7/pHA-TMZ/TCPP-Lip was a spheroid with a mean diameters of 143 ± 3.214 nm, a polydispersity index of 0.203 ± 0.025 and a surface charge of -22.8 ± 0.425 mV. The drug loadings (TMZ and TCPP) are 7.40 ± 0.23% and 2.05 ± 0.03% (mg/mg); and the encapsulation efficiencies are 81.43 ± 0.51% and 84.28 ± 1.64% (mg/mg). The results showed that BTP-7/pHA-TMZ/TCPP-Lip presented enhanced targeting and cytotoxicity.

CONCLUSION

BTP-7/pHA-TMZ/TCPP-Lip can specifically target the tumour cells to achieve efficient drug delivery, and improve the anti-tumour efficacy and reduces the systemic toxicity.

Liposomes against Alzheimer's Disease: Current Research and Future Prospects

Alzheimer's disease, the most common neurodegenerative disease, affects more than 60 million people worldwide, a number that is estimated to double by 2050. Alzheimer's disease is characterized by progressive memory loss, the impairment of behavior, and mood changes, as well as the disturbed daily routine of the patient. Although there are some active molecules that can be beneficial by halting the progression of the disease, the blood-brain barrier and other physiological barriers hinder their delivery and, consequently, the appropriate management of the disease. Therefore, drug delivery systems that effectively target and overcome the blood-brain barrier to reach the targeted brain area would improve treatment effectiveness. Liposomes are lipophilic carriers that consist of a phospholipid bilayer structure, simulating the physiological lipidic layer of the blood-brain barrier and enabling better delivery of the drug to the brain. Given that pure liposomes may have less targeting affinity than functionalized liposomes, modification with groups such as lactoferrin, poly(ethylene glycol), and transferrin may improve specificity. In this mini-review, we summarize the literature on the use of liposomes for the treatment of Alzheimer's disease, focusing on the functionalization moieties of liposomes. In addition, challenges in brain delivery are also discussed.

SSK1-Loaded Neurotransmitter-Derived Nanoparticles for Alzheimer's Disease Therapy via Clearance of Senescent Cells

Age is a significant contributor to the onset of AD. Senolysis has been recently demonstrated to ameliorate aging-associated diseases that showing a great potential in AD therapy. However, due to the presence of BBB, the anti-AD activity of senolytics are significantly diminished. SSK1 is a prodrug that can be activated by β-gal, a lysosomal enzyme commonly upregulated in senescent cells, and thus selectively eliminates senescent cells. Furthermore, the level of β-gal is significantly correlated with conventional AD genes from clinical sequencing data. SSK1-loaded neurotransmitter -derived lipid nanoparticles are herein developed (SSK1-NPs) that revealing good BBB penetration and bioavailability of in the body. At the brain lesion, SSK1-NP treatment significantly reduces the expression of genes associated with senescence, induced senescent cells elimination, decreased amyloid-beta accumulation, and eventually improve cognitive function of aged AD mice. SSK1-NPs, a novel nanomedicine displaying potent anti-AD activity and excellent safety profile, provides a promising strategy for AD therapy.

Biomaterials-based anti-inflammatory treatment strategies for Alzheimer's disease

The current therapeutic drugs for Alzheimer's disease only improve symptoms, they do not delay disease progression. Therefore, there is an urgent need for new effective drugs. The underlying pathogenic factors of Alzheimer's disease are not clear, but neuroinflammation can link various hypotheses of Alzheimer's disease; hence, targeting neuroinflammation may be a new hope for Alzheimer's disease treatment. Inhibiting inflammation can restore neuronal function, promote neuroregeneration, reduce the pathological burden of Alzheimer's disease, and improve or even reverse symptoms of Alzheimer's disease. This review focuses on the relationship between inflammation and various pathological hypotheses of Alzheimer's disease; reports the mechanisms and characteristics of small-molecule drugs (e.g., nonsteroidal anti-inflammatory drugs, neurosteroids, and plant extracts); macromolecule drugs (e.g., peptides, proteins, and gene therapeutics); and nanocarriers (e.g., lipid-based nanoparticles, polymeric nanoparticles, nanoemulsions, and inorganic nanoparticles) in the treatment of Alzheimer's disease. The review also makes recommendations for the prospective development of anti-inflammatory strategies based on nanocarriers for the treatment of Alzheimer's disease.

ApoE-modified liposomes encapsulating resveratrol and salidroside alleviate manifestations of Alzheimer's disease in APP/PS-1 mice

OBJECTIVE

Alzheimer's disease (AD) is a neurodegenerative disease that is associated with aging and is influenced by both genetic and environmental factors. Several studies and clinical trials have demonstrated that resveratrol (Res) and salidroside (Sal) are not only biologically safe but also influence AD biomarker trajectories. However, their clinical applications have been quite limited due to poor specificity, low solubility, and insufficient blood-brain barrier (BBB) penetration. Therefore, we developed a nano-drug delivery system in which Res and Sal were encapsulated in liposomes, which were surface-modified with ApoE (ApoE-Res/Sal-Lips) to compensate for these deficiencies.

METHOD

In this study, ApoE-Res/Sal-Lips were prepared using a standard thin-film hydration method for liposomes. Then, cellular uptake of the loaded liposomes was assessed in vitro using fluorescent staining assays. A BBB model was constructed to investigate the capacity of the liposomes to cross the BBB in vitro, and the ability of liposomes to target the brain was observed by in vivo imaging. In addition, the neuroprotective effects of the different liposome formulations in APP/PS-1 mice were evaluated by measuring the changes in levels of oxidative, anti-inflammatory, and anti-apoptotic factors in the mice brains.

RESULTS

In vitro, ApoE-Res/Sal-Lips increased the uptake of Res and Sal by bEnd.3 and N2a cells, enhanced BBB penetration, and improved transport efficiency. In vivo, the ApoE-Res/Sal-Lips were found to alleviate AD pathological symptoms, reduce learning and memory impairments, and improve brain function.

CONCLUSION

ApoE-Res/Sal-Lips provide a new method for the treatment of AD.

Conjugation, Prodrug, and Co-Administration Strategies in Support of Nanotechnologies to Improve the Therapeutic Efficacy of Phytochemicals in the Central Nervous System

Phytochemicals, produced as secondary plant metabolites, have shown interesting potential therapeutic activities against neurodegenerative diseases and cancer. Unfortunately, poor bioavailability and rapid metabolic processes compromise their therapeutic use, and several strategies are currently proposed for overcoming these issues. The present review summarises strategies for enhancing the central nervous system's phytochemical efficacy. Particular attention has been paid to the use of phytochemicals in combination with other drugs (co-administrations) or administration of phytochemicals as prodrugs or conjugates, particularly when these approaches are supported by nanotechnologies exploiting conjugation strategies with appropriate targeting molecules. These aspects are described for polyphenols and essential oil components, which can improve their loading as prodrugs in nanocarriers, or be part of nanocarriers designed for targeted co-delivery to achieve synergistic anti-glioma or anti-neurodegenerative effects. The use of in vitro models, able to simulate the blood-brain barrier, neurodegeneration or glioma, and useful for optimizing innovative formulations before their in vivo administration via intravenous, oral, or nasal routes, is also summarised. Among the described compounds, quercetin, curcumin, resveratrol, ferulic acid, geraniol, and cinnamaldehyde can be efficaciously formulated to attain brain-targeting characteristics, and may therefore be therapeutically useful against glioma or neurodegenerative diseases.

Nanoparticles-based anti-aging treatment of Alzheimer's disease

Age is the strongest risk factor for Alzheimer's disease (AD). In recent years, the relationship between aging and AD has been widely studied, with anti-aging therapeutics as the treatment for AD being one of the mainstream research directions. Therapeutics targeting senescent cells have shown improvement in AD symptoms and cerebral pathological changes, suggesting that anti-aging strategies may be a promising alternative for AD treatment. Nanoparticles represent an excellent approach for efficiently crossing the blood-brain barrier (BBB) to achieve better curative function and fewer side effects. Thereby, nanoparticles-based anti-aging treatment may exert potent anti-AD therapeutic efficacy. This review discusses the relationship between aging and AD and the application and prospect of anti-aging strategies and nanoparticle-based therapeutics in treating AD.

Rosmarinus officinalis and Methylphenidate Exposure Improves Cognition and Depression and Regulates Anxiety-Like Behavior in AlCl3-Induced Mouse Model of Alzheimer’s Disease

Alzheimer’s disease (AD) is a neurological illness that causes severe cognitive impairment. AD patients also experience at least one of the neuropsychiatric symptoms including apathy, depression, and anxiety during the course of their life. Acetylcholine esterase inhibitors are the available treatment options to alleviate cognitive deficits, whereas methylphenidate (MPH), a psychostimulant, is considered for the treatment of apathy in AD patients. Rosmarinus officinalis, a perennial herb, has been potentially known to have antioxidant and anti-inflammatory properties. The present study investigated the potential effects of MPH and R. officinalis in comparison with the standard drug, Donepezil, on cognition, anxiety, and depression in the AlCl₃-induced mouse model of AD. The animals were divided into eight groups (n = 8, each). The results revealed that the MPH- and R. officinalis-treated groups significantly improved memory impairment, whereas R. officinalis substantially reduced depression and anxiety as compared with other treatment groups. MPH treatment induced an antidepressant effect and increased anxiety-like behavior. Moreover, the AlCl₃ exposure led to the formation of amyloid beta (Aβ) plaques in mice hippocampus; however, none of the tested drugs caused a significant reduction in amyloid burden at the selected doses. The present study suggested the potential of R. officinalis to improve memory as well as neuropsychiatric symptoms in AD. Although R. officinalis improved cognitive abilities, it did not reduce the amyloid plaque burden, which indicates that the memory-enhancing effects of R. officinalis are due to some alternate mechanism that needs to be explored further.

Use of leptin-conjugated phosphatidic acid liposomes with resveratrol and epigallocatechin gallate to protect dopaminergic neurons against apoptosis for Parkinson's disease therapy

Complex liposomes were assembled with 1,2-distearoyl-sn-glycero-3-phosphocholine, dihexadecyl phosphate (DHDP), cholesterol and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (PA) to act as drug carriers for resveratrol (RES) and epigallocatechin gallate (EGCG). The liposomes were modified with leptin (Lep) on the surface to cross the blood-brain barrier (BBB) and to rescue degenerated dopaminergic neurons. The activity of RES and EGCG against neurotoxicity was investigated using an in vitro neurodegenerative model established by SH-SY5Y cells with an insult of 1-methyl-4-phenylpyridinium (MPP⁺). The results indicated that increasing the mole percentage of DHDP and PA increased the particle size and absolute zeta potential value, and improved the entrapment efficiency of RES and EGCG; however, this increase reduced the release rate of RES and EGCG and the grafting efficiency of Lep. The ability of Lep/RES-EGCG-PA-liposomes to cross the BBB was found to be higher than that of non-modified liposomes. Further, the addition of PA and Lep into liposomes enhanced cell viability and target efficiency. The immunofluorescence results demonstrated that the conjugation of Lep with liposomes enabled the docking of HBMECs and SH-SY5Y cells via Lep receptor, and enhanced their ability to permeate the BBB and cellular uptake. Immunofluorescence and western blot analysis also revealed that RES and EGCG encapsulated into liposomes could be a neural defensive strategy by reducing the apoptosis promotor protein Bcl-2 associated X protein and α-synuclein, and enhancement in the apoptosis inhibitor protein B cell lymphoma 2, tyrosine hydroxylase, and the dopamine transporter. Hence, Lep-PA-liposomes can be an excellent choice of potential delivery system for PD treatment.