Different HNMs have been widely tested for drug delivery applications. The advantages of this strategy are several including enhance drug solubility and the possibility of targeting and multivalent effects. As a potential broad spectral antiviral agent, AgNPs can prevent the virus from adsorbing to the host cell in the early stage of infection and thus show strong antiviral activity. After the cells are infected by the virus, there are ways to inhibit cell apoptosis (Figure 2, right). For example, Lv et al. studied the anti-TGEV activity of AgNPs in swine testicle cells and explored the possible mechanism of AgNP inhibition of TGEV infection-induced apoptosis.18 The results showed that these AgNPs are able to decrease cell apoptosis through the activation of p38/mitochondria-caspase-3 signaling.18