China
Africa
Explore chapters and articles related to this topic
Phosphorus-Containing Dendrimers Against Diseases of the Central Nervous System
Published in Anne-Marie Caminade, Cédric-Olivier Turrin, Jean-Pierre Majoral, Phosphorus Dendrimers in Biology and Nanomedicine, 2018
Anne-Marie Caminade, Cedric-Olivier Turrin, Jean-Pierre Majoral
Alzheimer’s disease is characterized by two hallmarks in the brain: the accumulation of ft-amyloid, a low molecular weight peptide, which aggregates into fibrils then plaques, and the accumulation of hyperphosphorylated MAP-tau protein into neurofibrillar tangles. As indicated in the previous paragraphs, the prion peptide PrP 185-208 has an analogous sphingolipid-binding domain to that of Alzheimer’s peptide 1-28; thus, the interaction between Alzheimer’s peptide 1-28 (Aft1-28) and positively charged poly(phosphorhydrazone) (PPH) dendrimers (generations 3 and 4) was also studied. As for the previous experiments, the aggregation process into fibrils was monitored in particular using the fluorescence of Thioflavin T (ThT) as a fluorescent probe. The experiments were carried out from t = 0 to t = 180 min. In all cases, a plateau was reached after about 150 min. A nonlinear effect of concentration in dendrimers was observed on the occurrence of the amyloid fibril formation. At very low concentration in dendrimer G3 or G4 (0.01 gM), acceleration of the fibril formation was observed. The plateau was reached only after 60 min, and the final amount of fibrils was significantly higher than for the control (without dendrimer). On the contrary, at high concentrations (1 and 10 gM), both dendrimers completely inhibited the aggregation process of Aβ1-28 (Fig. 11.4). The results were confirmed by transmission electron microscopy images. Moreover, it was observed that the PPH dendrimers significantly reduced the toxicity caused by the aggregated forms of Aβ1-28 toward mouse neuroblastoma cell line (N2a) [20].
Inside Alzheimer's Disease Diagnosis
Published in Parimelazhagan Thangaraj, Lucindo José Quintans Júnior, Nagamony Ponpandian, Nanophytomedicine, 2023
Gomathi Rajkumar, Murugan Rajan, Mairim Russo Serafini, Narendra Narain, Adriano A.S. Araujo, Lucindo José Quintans Júnior, Lijing Ke
Fluorescent dye-loaded NPs are used in the diagnosis of AD. Thioflavin-T (ThT) is a widely used dye for in vivo amyloid detection. ThT-loaded nanocapsules containing polybutyl cyanoacrylate (PBCA) that were injected into the intracerebral region of mice in vivo were found to pass through the BBB and interact with fibrillary Aβ species after a biodegradation-induced release from the carriers, as evidenced in using confocal laser scanning microscopy studies. Despite the fact that ThT is hydrophilic, PBCA enhanced the ability of NPs to pass the BBB and favoured the visualization of Aβ peptide pathology in in vivo studies (Roney et al., 2005).
Exploration of ligand-induced protein conformational alteration, aggregate formation, and its inhibition: A biophysical insight
Published in Preparative Biochemistry and Biotechnology, 2018
Saima Nusrat, Rizwan Hasan Khan
Thioflavin T is used for the detection of amyloid fibrils in vitro.[124] ThT added to a sample containing preformed β-sheet, and excited at 440 nm, gives a strong fluorescence with emission maxima at around 485 nm[125] Evidences show that ThT molecules most probably intercalate between grooves that are present in side chains of amyloid exposed to the solvent. ThT binds only to β-sheet structure present in amyloid fibrils but not to β-sheet structures present in the native protein.