**4. Conclusions**

In summary, we first fabricated gelatin/ZnO fibers via side-by-side electrospinning technique as a potential wound dressing. The data indicate that ZnO particles can be uniformly dispersed on the surface of gelatin fibers. Although gelatin/ZnO fibers have some inhibitory effect on MRC-5 cells, the corresponding cytotoxicity level is 0 or 1 per the standard, which indicates that fibers have no cytotoxicity. Moreover, the gelatin/ZnO fibers show excellent antibacterial activity against *E. coli* and *S. aureus*, which is caused by the superoxide radicals (·O2 −) produced by ZnO particles. In addition, the reductions of bacteria are all more than 90%. The experiments imply that gelatin/ZnO fibers have excellent application prospects for wound dressing.

**Author Contributions:** W.L., Y.G. and Y.C. Conceived and Designed the Experiments; Y.C. and Y.Z. Performed the Experiments and Analyzed the Data; Y.S. Contributed Reagents/Materials/Analysis Tools; Y.C., W.L. Wrote the Paper.

**Funding:** This work was supported by the State Natural Sciences Fund, China (Project No. 21506236, 51372276), Research and Application of Gelatin Green Manufacturing 2.0 Technology by Enzymatic method (KFJ-STS-ZDTP-016) and Hangzhou Research Institute of Technical Institute of Physics and Chemistry, CAS Fund (Project No. 2016050201, 2016050202).

**Conflicts of Interest:** The authors declare no conflict of interest.
