Recent times have witnessed an upsurge in the incidence of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Prion disease, and amyotrophic lateral sclerosis. The treatment of the same remains a daunting challenge due to the limited access of therapeutic moieties across the blood–brain barrier. Engineered nanoparticles with a size less than 100 nm provide multifunctional abilities for solving these biomedical and pharmacological issues due to their unique physico‐chemical properties along with capability to cross the blood–brain barrier. Needless to mention, there is a scarcity of review articles summarizing recent developments of various nanomaterials including liposomes, polymeric nanoparticles, metal nanoparticles, and bio‐nanoparticles toward the therapeutic and theranostics applications for various neurodegenerative disorders. Here, a broad spectrum of nanomedicinal approaches to eradicate neurodegenerative disorders is provided, along with a brief account of neuroprotection and neuronal tissue regeneration, current clinical status, issues related to safety, toxicity, challenges, and future outlook.

A biocompatible fluorescent hydroxyquinoline-affixed polyfluorene (PF-HQ) nanoparticle-based drug delivery system (DDS: PF-HQ–DOX) is utilized for cancer cell imaging, transport and delivery of the FDA-approved drug doxorubicin (DOX), and theranostics applications.

Inhibitory modulation toward de novo protein aggregation is likely to be a vital and promising therapeutic strategy for understanding the molecular etiology of amyloid related diseases such as Alzheimer's disease (AD). The building up of toxic oligomeric and fibrillar amyloid aggregates in the brain plays host to a downstream of events, causing damage to axons, dendrites, synapses, signaling, transmission, and finally cell death. Herein, we introduce a novel conjugated polymer (CP), hydroxyquinoline appended polyfluorene (PF-HQ), which has a typical "amyloid like" surface motif and exhibits inhibitory modulation effect on amyloid β (Aβ) aggregation. We delineate inhibitory effects of PF-HQ based on Thioflavin T (ThT) fluorescence, atomic force microscopy (AFM), circular dichroism (CD), and Fourier transform infrared (FTIR) studies. The amyloid-like PF-HQ forms nano coaggregates by templating with toxic amyloid intermediates and displays improved inhibitory impacts toward Aβ fibrillation and diminishes amyloid cytotoxicity. We have developed a CP based modulation strategy for the first time, which demonstrates beneficiary amyloid-like surface motif to interact efficiently with the protein, the pendant side groups to trap the toxic amyloid intermediates as well as optical signal to acquire the mechanistic insight.

Alzheimer's disease (AD) is associated with different types of amyloid peptide aggregates including senile plaques, fibrils, protofibrils, and oligomers. Due to these difficulties, a powerful strategy is needed for the disaggregation of amyloid aggregates by modulating their self-aggregation behavior. Herein, we report a unique approach toward transforming the aggregated amyloidogenic peptides using an amino acid functionalized perylene diimide as a molecular modulator, which is a different nondestructive approach as compared to inhibiting the aggregation of peptides. The histidine functionalized perylenediimide (PDI-HIS) molecule could coassemble with amyloid β (Aβ) peptides via hydrogen bonding that leads to the enhancement in the π-π interactions between Aβ and PDI-HIS moieties. The Thioflavin T (ThT) assay and various spectroscopic and microscopic techniques establish that the PDI-HIS molecules accelerate the Aβ1-40 and the amyloid aggregates in CSF into micro size coassembled structures. These results give rise to a new and unique complementary approach for modulating the biological effects of the aggregates in amyloidogenic peptides.