Engineered Hydroxyapatite–Baicalin Nanorods with Sharp Edges for Broad-Spectrum Antiviral Applications

The sharp-edged structure of inorganic nanomaterials has attracted considerable interest due to its potential to confer broad-spectrum antiviral properties. Herein, a series of hydroxyapatite-balance-based (HA-B) nanorods with well-defined aspect ratios were synthesized to investigate their antiviral activity. Among them, HA-B_0.05wt% exhibited the highest aspect ratio (AR = 11.7 ± 4.7) and demonstrated potent, broad-spectrum antiviral activity against enveloped virus, including pseudorabies virus (PRV, DNA virus), transmissible gastroenteritis virus (TGEV, RNA virus), and porcine epidemic diarrhea virus (PEDV, RNA virus). For extracellular viruses, HA-B_0.05wt% exerts its antiviral effect primarily through the physical disruption of viral envelopes, facilitated by its sharp-edged nanostructures. In the case of intracellular viruses, HA-B_0.05wt% mitigates infection by attenuating virus-induced intracellular reactive oxygen species (ROS) accumulation and activating the host's innate immune responses, thereby effectively suppressing viral replication and release. Furthermore, <i>in vivo</i> evaluation demonstrated that treatment with HA-B_0.05wt% significantly reduced viral load and improved survival rates in PRV-infected mice. Collectively, these findings highlight HA-B_0.05wt% as a promising candidate for broad-spectrum antiviral therapy with potential applications in biosecurity and infectious disease control.