Mixed Carboxyl and Hydrophobic Dendrimer Surface Inhibits Amyloid-β Fibrillation: New Insight from the Generation Number Effect

Influence of dual succinylation and ultrasonication modification on the amino acid content, structural and functional properties of Chickpea (Cicer arietinum L.) protein concentrate

Chickpea protein, a valuable plant-based source, offers versatile applications, yet the impact of modifications like succinylation and ultrasonication on its properties remains unclear. This study explored dual succinylation and ultrasonication modification to enhance its functionality and application. Modified chickpea protein with a degree of succinylation of 96.75 %, showed enhanced water holding capacity 39.83 %, oil holding capacity 54.02 %, solubility 7.20 %, and emulsifying capacity 23.17 %, compared to native protein. Despite reduced amino acid content (64.50 %), particularly lysine, succinylation increased sulfhydryl by 1.74 %, reducing hydrophobicity (Ho) by 41.87 % and causing structural changes. Ultrasonication further reduced particle size by 82.57 % and increased zeta potential and amino acid content (57.47 %). The dual-modified protein exhibited a non-significant increase in antimicrobial activity against Staphylococcus aureus (25.93 ± 1.36 mm) compared to the native protein (25.28 ± 1.05 mm). In conclusion, succinylation combined with ultrasonication offers a promising strategy to enhance chickpea protein's physicochemical properties for diverse applications.

Inhibitors of amyloid fibril formation

Many diseases are caused by misfolded and denatured proteins, leading to neurodegenerative diseases. In recent decades researchers have developed a variety of compounds, including polymeric inhibitors and natural compounds, antibodies, and chaperones, to inhibit protein aggregation, decrease the toxic effects of amyloid fibrils, and facilitate refolding proteins. The causes and mechanisms of amyloid formation are still unclear, and there are no effective treatments for Amyloid diseases. This section describes research and achievements in the field of inhibiting amyloid accumulation and also discusses the importance of various strategies in facilitating the removal of aggregates species (refolding) in the treatment of neurological diseases such as chemical methods like as, small molecules, metal chelators, polymeric inhibitors, and nanomaterials, as well as the use of biomolecules (peptide and, protein, nucleic acid, and saccharide) as amyloid inhibitors, are also highlighted.

Dendrimers and Derivatives as Multifunctional Nanotherapeutics for Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent form of dementia. It affects more than 30 million people worldwide and costs over US$ 1.3 trillion annually. AD is characterized by the brain accumulation of amyloid β peptide in fibrillar structures and the accumulation of hyperphosphorylated tau aggregates in neurons, both leading to toxicity and neuronal death. At present, there are only seven drugs approved for the treatment of AD, of which only two can slow down cognitive decline. Moreover, their use is only recommended for the early stages of AD, meaning that the major portion of AD patients still have no disease-modifying treatment options. Therefore, there is an urgent need to develop efficient therapies for AD. In this context, nanobiomaterials, and dendrimers in particular, offer the possibility of developing multifunctional and multitargeted therapies. Due to their intrinsic characteristics, dendrimers are first-in-class macromolecules for drug delivery. They have a globular, well-defined, and hyperbranched structure, controllable nanosize and multivalency, which allows them to act as efficient and versatile nanocarriers of different therapeutic molecules. In addition, different types of dendrimers display antioxidant, anti-inflammatory, anti-bacterial, anti-viral, anti-prion, and most importantly for the AD field, anti-amyloidogenic properties. Therefore, dendrimers can not only be excellent nanocarriers, but also be used as drugs per se. Here, the outstanding properties of dendrimers and derivatives that make them excellent AD nanotherapeutics are reviewed and critically discussed. The biological properties of several dendritic structures (dendrimers, derivatives, and dendrimer-like polymers) that enable them to be used as drugs for AD treatment will be pointed out and the chemical and structural characteristics behind those properties will be analysed. The reported use of these nanomaterials as nanocarriers in AD preclinical research is also presented. Finally, future perspectives and challenges that need to be overcome to make their use in the clinic a reality are discussed.

Advanced bioactive nanomaterials for diagnosis and treatment of major chronic diseases

With the rapid innovation of nanoscience and technology, nanomaterials have also been deeply applied in the medical and health industry and become one of the innovative methods to treat many diseases. In recent years, bioactive nanomaterials have attracted extensive attention and have made some progress in the treatment of some major chronic diseases, such as nervous system diseases and various malignant tumors. Bioactive nanomaterials depend on their physical and chemical properties (crystal structure, surface charge, surface functional groups, morphology, and size, etc.) and direct produce biological activity and play to the role of the treatment of diseases, compared with the traditional nanometer pharmaceutical preparations, biological active nano materials don't exert effects through drug release, way more directly, also is expected to be more effective for the treatment of diseases. However, further studies are needed in the evaluation of biological effects, fate in vivo, structure-activity relationship and clinical transformation of bionanomaterials. Based on the latest research reports, this paper reviews the application of bioactive nanomaterials in the diagnosis and treatment of major chronic diseases and analyzes the technical challenges and key scientific issues faced by bioactive nanomaterials in the diagnosis and treatment of diseases, to provide suggestions for the future development of this field.

Dendrimers as Antiamyloid Agents

Dendrimer-protein conjugates have significant prospects for biological applications. The complexation changes the biophysical behavior of both proteins and dendrimers. The dendrimers could influence the secondary structure of proteins, zeta-potential, distribution of charged regions on the surface, the protein-protein interactions, etc. These changes offer significant possibilities for the application of these features in nanotheranostics and biomedicine. Based on the dendrimer-protein interactions, several therapeutic applications of dendrimers have emerged. Thus, the formation of stable complexes retains the disordered proteins on the aggregation, which is especially important in neurodegenerative diseases. To clarify the origin of these properties and assess the efficiency of action, the mechanism of protein-dendrimer interaction and the nature and driving force of binding are considered in this review. The review outlines the antiamyloid activity of dendrimers and discusses the effect of dendrimer structures and external factors on their antiamyloid properties.

Recent advances in nanoplatforms for the treatment of neuropathic pain

STUDY DESIGN

Narrative review.

OBJECTIVES

The objective was to summarize the literature on nanoplatforms in spinal cord injury (SCI) and describe their effect in facilitating experiments for SCI. Currently, the primary clinical treatment for neuropathic pain (NP) is drug therapy, but these traditional drugs have many disadvantages, such as high dose, rapid clearance from the circulatory system, off-target side effects, and cytotoxicity. Moreover, the treatment for NP is complicated by the existence of blood-brain barrier. In recent years, nanomedicine has been receiving increased attention; this novel modality could help deliver drugs to treat NP via nanoplatforms, making it a promising alternative therapy. The use of nanoplatforms can enhance pharmaceutic effectiveness by either avoiding rapid clearance from the blood or ensuring adequate concentration in the lesion.

METHODS

A literature review was conducted, with a focus on nanoplatforms that have been described in the experimental studies of neuropathic pain.

RESULTS

We provide a brief description of the roles of liposomes, polymeric nanoparticles, metal nanoparticles, micelles, and dendrimers in the treatment of NP and discuss the prospective development of the nanoplatform system for NP.

CONCLUSION

The emergence of various nanoplatform drug delivery systems can provide an advantageous resource tool for real-time diagnosis and effective treatment of SCI-related NP.

Reversing Aβ Fibrillation and Inhibiting Aβ Primary Neuronal Cell Toxicity Using Amphiphilic Polyphenylene Dendrons

Uncontrolled amyloid-beta (Aβ) fibrillation leads to the deposition of neurotoxic amyloid plaques and is associated with Alzheimer's disease. Inhibiting Aβ monomer fibrillation and dissociation of the formed fibers is regarded as a promising therapeutic strategy. Here, amphiphilic polyphenylene dendrons (APDs) are demonstrated to interrupt Aβ assembly and reduce Aβ-cell interactions. Containing alternating negatively charged sulfonic acid and hydrophobic n-propyl peripheral groups, APDs bind to the secondary structure of the Aβ aggregates, inhibiting fibrillation and disassemble the already formed Aβ fibrils. APDs reveal vesicular cellular uptake in endosomes as well as cell compatibility for endothelial and neuronal cells, and significantly reduce Aβ-induced neuron cytotoxicity in vitro. Moreover, they are transported into the brain and successfully cross the blood-brain barrier after systemic application in mice, indicating their high potential to inhibit Aβ fibrillation in vivo, which can be beneficial for developing therapeutic strategy for Alzheimer's disease.

Inhibition and disruption of amyloid formation by the antibiotic levofloxacin: A new direction for antibiotics in an era of multi-drug resistance

Neurodegenerative diseases are a group of debilitating maladies involving protein aggregation. To this day, all advances in neurodegenerative disease therapeutics have helped symptomatically but have not prevented the root cause of the disease, i.e., the aggregation of involved proteins. Antibiotics are becoming increasingly obsolete due to the rising multidrug resistance strains of bacteria. Thus, antibiotics, if put to different use as therapeutics against other diseases, could pave a new direction to the world of antibiotics. Hence, we studied the antibiotic levofloxacin for its potential anti-amyloidogenic behavior using human lysozyme, a protein involved in non-systemic amyloidosis, as a model system. At the sub-stoichiometric level, levofloxacin was able to inhibit amyloid formation in human lysozyme as observed by various spectroscopic and microscopic methods, with IC₅₀ values as low as 8.8 ± 0.1 μM. Levofloxacin also displayed a retarding effect on seeding phenomena by elongating the lag-phase (from 0 to 88 h) at lower concentration, and arresting lysozyme fibrillation at the lag stage in sub-stoichiometric concentrations. Structural and computational analyses provided mechanistic insight showing that levofloxacin stabilizes the lysozyme in the native state by binding to the aggregation-prone residues, and thereby inhibiting amyloid fibrillation. Levofloxacin also showed the property of disrupting amyloid fibrils into a smaller polymeric form of proteins which were less cytotoxic as confirmed by hemolytic assay. Therefore, we throw new light on levofloxacin as an amyloid inhibitor and disruptor which could pave way to utilization of levofloxacin as a potential therapeutic against non-systemic amyloidosis and neurodegenerative diseases.

The membrane axis of Alzheimer's nanomedicine

Alzheimer's disease (AD) is a major neurological disorder impairing its carrier's cognitive function, memory and lifespan. While the development of AD nanomedicine is still nascent, the field is evolving into a new scientific frontier driven by the diverse physicochemical properties and theranostic potential of nanomaterials and nanocomposites. Characteristic to the AD pathology is the deposition of amyloid plaques and tangles of amyloid beta (Aβ) and tau, whose aggregation kinetics may be curbed by nanoparticle inhibitors via sequence-specific targeting or nonspecific interactions with the amyloidogenic proteins. As literature implicates cell membrane as a culprit in AD pathogenesis, here we summarize the membrane axis of AD nanomedicine and present a new rationale that the field development may greatly benefit from harnessing our existing knowledge of Aβ-membrane interaction, nanoparticle-membrane interaction and Aβ-nanoparticle interaction.

Nanomaterial synthesis, an enabler of amyloidosis inhibition against human diseases

Amyloid diseases are global epidemics with no cure currently available. In the past decade, the use of engineered nanomaterials as inhibitors or probes against the pathogenic aggregation of amyloid peptides and proteins has emerged as a new frontier in nanomedicine. In this Minireview, we summarize for the first time the pivotal role of chemical synthesis in enabling the development of this multidisciplinary field.