Green Synthesis of Gold Nanoparticles Doped Paramylon Nanocomposites Using Phyllanthus niruri Extract and Their Multifaceted Biological Activity Evaluation

Abstract

This study reports the green synthesis of gold nanoparticle/Paramylon (AuNPs/Paramylon) nanocomposites using Phyllanthus niruri extract and evaluates their therapeutic potential. Successful nanocomposite formation was confirmed through characteristic surface plasmon resonance at 560 nm, spherical morphology (SEM), and semi-crystalline architecture with 70.3% crystallinity and 29.7% amorphous content (XRD). EDAX analysis verified 8.4% gold incorporation. The nanocomposites demonstrated multifunctional biological activities at 100 µg/ml, including antibacterial efficacy against Enterococcus faecalis and MRSA, potent antioxidant capacity (69.1% DPPH radical scavenging), remarkable anti-inflammatory activity (79.3% inhibition), and significant cytotoxicity (89% cell death, 11% viability in MTT assays). The semi-crystalline structure establishes a critical structure-activity relationship where crystalline gold cores facilitate ROS-mediated antimicrobial and antioxidant effects, while the amorphous Paramylon matrix enhances biocompatibility and cellular uptake. These findings highlight AuNPs/Paramylon nanocomposites as promising multifunctional therapeutic agents for biomedical applications.