Aim: In this work, we established a simple, controlled, and reproducible method to synthesize gallium-coated polydopamine (PDA) nanoparticles. Methods: Polydopamine was synthetized in the alkali medium with posterior gallium shell formation due to ion chelation on the nanoparticle surface. Results: The obtained results with EDS spectra confirmed the incorporation of gallium on PDA surface. The cytotoxicity of Ga-coated PDA nanoparticles was evaluated in vitro at different concentrations in contact with human adipose-derived stem cells (hASCs). Further cell analysis also demonstrated the benefit of Ga-coated PDA, which increased the cell proliferation rate compared to non-coated PDA. Conclusion: This study indicated that gallium could work as an appropriate shell for PDA particles, inducing cell proliferation at the analyzed concentrations.