Green synthesis of silver nanoparticles for antimalarial activity: Characterisation, acute toxicity, and efficacy studies in a murine model

Title : Green synthesis of silver nanoparticles for antimalarial activity: Characterisation, acute toxicity, and efficacy studies in a murine model

Abstract:

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.

Keywords: Silver Nanoparticles (AgNPs), Green Synthesis, Antimalarial, Plasmodium berghei, Biopolymer Passivation, Nanomedicine, Mechanism of Action.

Biography:

Goodnews Onyedikachi Ikeh is a Research Chemist, and a Doctoral Applicant at the prestigious Institute of Science and Technology Austria, where he hopes to specialise in the intersection of Green Chemistry and Dynamic Soft Matter. His current research goal is to bridge his expertise in sustainable nanoparticle synthesis (as evidenced by his published work on antimalarial agents) with the fundamental challenges of non-equilibrium supramolecular chemistry. His proposed doctoral project, "Dissipative Supramolecular Assembly with Green-Synthesised Nanoparticles," seeks to establish the fundamental kinetic and mechanistic rules for creating autonomous materials that self-regulate and possess a tunable lifespan—a crucial step toward developing the next generation of sustainable and self-regulating therapeutic and catalytic systems. He is dedicated to translating analytical rigor into foundational scientific discovery. Based in the Department of Pharmaceutical and Medicinal Chemistry, at the Enugu State University of Science and Technology, Nigeria, he contributes to advancing scientific knowledge in Chemistry and Biochemistry through rigorous research and laboratory expertise. As a board-certified and licensed Laboratory Technologist, he brings precision and innovation to his work in academic and research settings