2.3.2 Inflammatory regulation ability
Macrophages are innate immune cells that play a key role in host defense, wound healing, and immune regulation.[37]In the early stages of wound, M1 can cause inflammation and resist infection. However, after wound antibacterial procedure, it is necessary for macrophages to transition from M1 type to M2 type as soon as possible in order to more effectively promote the process of wound repair. ADSCs have been proven to promote wound repair and regulate inflammation.[38,39] Therefore, ANVs derived from ADSCs are expected to have the ability to regulate inflammation as well. To test this hypothesis, we used the lipopolysaccharide (LPS)-induced M1 phenotype as a positive control, while inactivated M0 as a negative control. As shown in Figure 2E~2G, macrophages incubated with the ANVs or THB@ANVs expressed a significant inhibition of pro-inflammatory factors (TNF-α, IL-6) and promotion of anti-inflammatory factors (IL-10). Taken together, the massively produced functionalized THB@ANVs can preserving the wound healing effect of original stem cells, and the cells exhibit little mutual repulsion towards ANVs from different individuals, enabling this kind of nanovesicles to have broad applications.