Green Synthesis of Silver Nanoparticles for Antimalarial Activity: Characterisation, Acute Toxicity, and Efficacy Studies in a Murine Model
Keywords:
Silver Nanoparticles (AgNPs), Green Synthesis, Antimalarial, Plasmodium berghei, Biopolymer Passivation, Nanomedicine, Mechanism of ActionAbstract
Recent studies highlight the therapeutic potential of green-synthesized silver nanoparticles (AgNPs), yet the precise mechanisms supporting their favourable safety profiles and biological efficacy remain underexplored, particularly concerning the role of their unique biopolymer matrix. We hypothesized that the extensive biopolymer passivation layer, inherent to green synthesis, is the critical determinant responsible for both the observed low toxicity and the enhanced antimalarial action of AgNPs. To test this, we synthesized AgNPs using a plant extract and performed comprehensive characterisation and in vivo antimalarial assessments. Our results confirmed the formation of spherical AgNPs with an optimal hydrodynamic size (43.04 nm). Crucially, multi-modal characterization (UV-Vis SPR red-shift at 431 nm, DLS/TEM size discrepancy, FTIR, EDX) converged to establish a thick, protective organic biopolymer matrix encapsulating the silver core, explaining the weak metallic signal in XRD. This unique structural feature directly correlated with an exceptionally favourable acute safety profile (LD50 > 5000 mg/kg), confirming the biopolymer's role in toxicity mitigation. Furthermore, these AgNPs demonstrated significant in vivo suppression of Plasmodium berghei parasitemia, primarily driven by a multifaceted mechanism: enhanced endocytic uptake into infected red blood cells (iRBCs) facilitated by the biopolymer coating, followed by targeted disruption of parasite heme detoxification, and induction of oxidative stress. This study reveals that the biopolymer matrix, a defining characteristic of green-synthesized AgNPs, is not merely a by-product but a key mechanistic modulator dictating both safety and antimalarial efficacy, providing critical insights for engineering biocompatible nanotherapeutics.
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Published on: 10-01-2025
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