Nanoparticle‐Mediated Delivery of Adenosine 5′‐Monophosphate Enhances 5‐Oxoprolinase Activity to Mitigate Oxidative Stress in Heart Failure

ABSTRACT Oxidative stress, a key driver of heart failure progression, is exacerbated by 5‐oxoproline accumulation due to reduced 5‐oxoprolinase (OPLAH) activity. While enhancing OPLAH function represents a promising therapeutic strategy, effective intracellular delivery of activity‐modulating compounds remains highly challenging. Here, we develop a comprehensive approach combining high‐throughput screening technology and advanced nanocarrier design to address effective intracellular delivery. Through the screening of an FDA‐approved compound library, we identify adenosine 5′‐monophosphate (AMP) as a novel OPLAH activator, demonstrating direct modulation through thermal shift assay and a dose‐dependent activation via liquid chromatography mass spectrometry (LC‐MS/MS) analysis. To overcome the AMP's limited cellular permeability, we engineer acetalated dextran spermine‐modified nanoparticles (AcDXSp‐NPs) with optimized physicochemical properties for efficient intracellular delivery. The AMP‐loaded nanoparticles exhibit a high encapsulation efficiency (>70%) and controlled pH‐dependent release. In cell‐based studies, these nanocarriers significantly enhance OPLAH activity, evidenced by a >50% increase in 13 C 5 ‐glutamate production from the isotope‐labeled 13 C 5 ‐5‐oxoproline. This integrated approach, combining enzyme activation with advanced delivery systems, may present a promising therapeutic strategy for oxidative stress‐related conditions, particularly conditions like heart failure; it also demonstrates the potential of materials‐based solutions for challenging therapeutic targets.