Dendrimeric Poly(Epsilon-Lysine) Delivery Systems for the Enhanced Permeability of Flurbiprofen across the Blood-Brain Barrier in Alzheimer's Disease.

Alzheimer's disease (AD) is a progressive brain disorder and age-related disease characterised by abnormal accumulation of ß-amyloid (Aß). The development of drugs to combat AD is hampered by the lack of therapeutically-active molecules able to cross the blood-brain barrier (BBB). It is agreed that specifically-designed carriers, such as dendrimers, could support the drug penetration across the BBB. The aim of this study was to design biocompatible and biodegradable dendrimeric delivery systems able to carry Flurbiprofen (FP), as drug for AD treatment, across the BBB and liberate it at the target tissue. These dendrons were synthesised using solid-phase peptide synthesis method and characterised by mass spectrometry and fourier-transform infrared spectroscopy (FTIR). The results revealed successful synthesis of dendrons having FP been integrated during the synthesis at their branching ends. Cytotoxicity assays demonstrated the biocompatibility of the delivery systems, whereas HPLC analysis showed high percentages of permeability across an in vitro BBB model for FP-integrated dendrons. Results also revealed the efficiency of drug conjugates on the γ-secretase enzyme in target cells with evidence of eventual drug release by hydrolysis of the carrier. This study demonstrates that the coupling of FP to dendrimeric delivery systems can successfully be achieved during the synthesis of the poly(epsilon-lysine) macromolecules to improve the transport of the active drug across the BBB.

Impact of the COVID-19 pandemic on dispensing medicines in the community pharmacy.

BACKGROUND: The world has faced an unprecedented challenge since COVID-19 emerged as a pandemic, which has led to quarantine and disruptions in drug services. During the pandemic, drug use habits and availability changed, causing a shift in behaviors and, in turn, medicine misuse. In Iraq, this is a major problem because many medicines can be easily obtained. OBJECTIVE: The study aims to describe the pattern of dispensing medications during the pandemic and to evaluate the biochemical and pathological consequences. METHOD: The analytical, observational, cross-sectional study was performed via a compiled questionnaire for 400 random pharmacists, and the analysis and interpretation of the biochemical changes and medical reports. RESULTS: Results revealed that dispensing of medications since the COVID-19 outbreak has increased by 74%, and the demand for medicines seems higher than required in comparison to the periods before the pandemic, while 60% of the dispensed medicines were taken just in case needed. In addition, the availability of medicines decreased by 61%, and the dispensing of common medicines increased due to the belief in their prophylactic action. Several biochemical abnormalities and pathological consequences were recorded due to the irrational use of medicines, and the highest percentage (12%) was seen in hepatic and liver enzymatic dysfunction and 8% for the endocrine and hormonal abnormalities. CONCLUSION: It can be concluded that most of the dispensed medicines were not used on a therapeutic or scientific basis during the pandemic.

A Peptide-Based Nanocarrier for an Enhanced Delivery and Targeting of Flurbiprofen into the Brain for the Treatment of Alzheimer's Disease: An In Vitro Study.

Alzheimer's disease (AD) is an age-related disease caused by abnormal accumulation of amyloid-ß in the brain leading to progressive tissue degeneration. Flurbiprofen (FP), a drug used to mitigate the disease progression, has low efficacy due to its limited permeability across the blood-brain barrier (BBB). In a previous work, FP was coupled at the uppermost branching of an ε-lysine-based branched carrier, its root presenting a phenylalanine moiety able to increase the hydrophobicity of the complex and enhance the transport across the BBB by adsorptive-mediated transcytosis (AMT). The present study explores a different molecular design of the FP-peptide delivery system, whereby its root presents an ApoE-mimicking peptide, a targeting ligand that could enhance transport across the BBB by receptor-mediated transcytosis (RMT). The functionalised complex was synthesised using a solid-phase peptide synthesis and characterised by mass spectrometry and FTIR. Cytotoxicity and permeability of this complex across an in vitro BBB model were analysed. Moreover, its activity and degradation to release the drug were investigated. The results revealed successful synthesis and grafting of FP molecules at the uppermost molecular branches of the lysine terminal without observed cytotoxicity. When covalently linked to the nanocarrier, FP was still active on target cells, albeit with a reduced activity, and was released as a free drug upon hydrolysis in a lysosome-mimicking medium. Noticeably, this work shows the high efficiency of RMT-driven FP delivery over delivery systems relying on AMT.

Designing and Characterization of a Novel Delivery System for Improved Cellular Uptake by Brain Using Dendronised Apo-E-Derived Peptide.

Neurodegenerative diseases (ND) are characterized by the progressive loss of neuronal structure or function mostly associated with neuronal death. The presence of the blood-brain barrier (BBB) is considered the main obstacle that prevents the penetration of almost all drugs rendering the diseases untreatable. Currently, one of the most promising approaches for drug delivery to the brain is by employing endogenous transcytosis to improve endothelial cell uptake. This study aimed to exploit this potential route of enhanced drug uptake through the design and characterization of low generations lysine dendrons with further functionalization of dendron with ApoE-derived peptide (AEP) ligand to improve cellular uptake and targeting of delivery to the brain. Dendrons and peptide were synthesized using solid phase peptide chemistry and the products were characterized by mass spectrometry and high performance liquid chromatography which confirmed the successful synthesis of dendrons and functionalization with the AEP. Cell viability and lactate dehydrogenase release were conducted to study the cytotoxicity of the materials against an immortalized brain endothelial cell line (bEnd.3) which demonstrated that no toxicity was seen at the concentration range used (up to 400 µM) for up to 48 h incubation. Cellular uptake of the synthesized molecules was examined using confocal microscopy and flow cytometer which clearly showed the cellular uptake of the dendronised carrier systems and that the highest percentage of cellular uptake was achieved with the AEP-functionalized dendron. This study has therefore demonstrated the successful synthesis of dendronised carrier systems with the potential to act as carriers for improved delivery and targeting the brain.