Peptoids: Emerging Therapeutics for Neurodegeneration

Abstract

In recent decades, the increasing prevalence of age-associated neurodegenerative diseases has underscored the need for targeted therapeutic strategies and novel diagnostics. Peptide-based neurotherapeutics offer high specificity and tolerability but are limited by proteolytic degradation in vivo. Peptoids, or N-substituted glycines, are versatile peptidomimetics that evade proteolytic degradation yet maintain many qualities that render peptides attractive neurotherapeutic candidates. These molecules may be engineered to their application through modifications that enhance structural stability and reactivity and can withstand various physiological stressors to retain their intended function within anomalous microenvironments. Peptoids generally demonstrate greater cellular permeability than their corresponding peptides, are less immunogenic, and can be administered intranasally, all properties that enhance their potential as neurotherapeutics. Peptoids have primarily been explored as aggregation inhibitors to prevent the deleterious protein plaque deposition associated with several neurodegenerative disorders. However, novel research has uncovered the potential of peptoids toward additional neurotherapeutic applications. Peptoids can modulate cell signaling pathways involved in axonal function and current modulation and can block cell signaling events associated with apoptosis. In addition, these peptidomimetics are able to function as anti- inflammatory agents via multiple mechanisms. Moreover, the versatility and low cost of peptoids render them ideal instruments in biomarker detection, discovery, and imaging. This mini-review explores these diverse applications of peptoids within the context of neurodegenerative disease.