Fig. 5: Examination of the properties of parenteral administration of zan-DNP.

a Structure of zanamivir-^99mTc conjugate (zan-^99mTc). b Binding of zanamivir-^99mTc to N1 neuraminidase (expressed on A/Puerto Rico/8/1934 (H1N1) virus-infected MDCK cells) in the absence (red curve) and presence (blue curve) of 100-fold excess zanamivir (competitor) (n = 3). c Biodistribution of intravenously injected (IV) zan-^99mTc in A/Puerto Rico/8/1934 (H1N1) virus-infected mice (3 mice/group). d SPECT/CT images showing the locations of intravenously injected zan-^99mTc in A/Puerto Rico/8/1934 (H1N1) virus-infected mice (left panel) or virus-infected mice which concurrently received 100-fold excess free zanamivir (right panel) (3 mice/group). a: lung; b: kidney; c: bowels. e Weight loss and survival curves of virus-infected mice treated with zan-DNP or zanamivir. DNP-KLH immunized BALB/c mice (5 mice/group) were challenged with 100x MLD₅₀ of the influenza virus strains indicated above each panel. Mice were treated with a single dose of zan-DNP by intraperitoneal administration (IP) 24 h post-infection. Mice were counted as dead when they lost either 25% of their initial weight or became moribund. Statistical differences between PBS and drug treatment groups were determined by two-sided log-rank test (*P < 0.005, see exact P values in Supplementary Table 1). Data are presented as mean values ± SD.