**4. Conclusions**

This study reports on the influence of different patterned piezoelectric P(VDF-TrFE) scaffolds in the preosteoblasts' proliferation and differentiation. It was observed that MC3T3-E1 cells differentiation can be induced solely by a physical stimulus, specifically by an isotropic hexagonal surface topography, with no need of using a chemical inducer. Finding that bone cells differentiation can be positively influenced by this type of geometry, it is concluded that novel scaffolds based on electromechanically active materials with specific geometries can provide the necessary geometrical and electroactive components of the bone microenvironment to support bone regeneration.

**Supplementary Materials:** Supplementary Materials can be found at http://www.mdpi.com/1422-0067/21/21/ 8352/s1. Figure S1. FTIR-ATR spectra of P(VDF-TrFE) scaffolds. Figure S2. Schematic representation of the produced patterned P(VDF-TrFE) scaffolds with linear microstructures. Figure S3. Schematic representation of the patterned P(VDF-TrFE) scaffolds with hexagonal microstructures. Figure S4. Cell adhesion of MC3T3-E1 on dense non-patterned P(VDF-TrFE) scaffolds.

**Author Contributions:** Conceptualization, V.F.C., S.L.-M. and C.R.; Data curation, T.M.-A.; Formal analysis, T.M.-A. and C.R.; Funding acquisition, S.L.-M. and C.R.; Investigation, T.M.-A., V.F.C., M.G., S.L.-M. and C.R.; Methodology, C.R.; Resources, M.G.; Supervision, S.L.-M. and C.R.; Writing—original draft, T.M.-A.; Writing—review & editing, V.F.C., M.G., S.L.-M. and C.R. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by national funds through the Fundação para a Ciência e Tecnologia (FCT) and by ERDF through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) in the framework of the Strategic Programs UID/FIS/04650/2020 and UIDB/04436/2020 and projects PTDC/EMD-EMD/28159/2017 and PTDC/BTM-MAT/28237/2017. TA thank FCT for the gran<sup>t</sup> SFRH/BD/141136/2018 and CR thanks the FCT for the contract under the Stimulus of Scientific Employment (DL57/2016 junior researcher contract). Finally, the authors acknowledge funding by Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033 and from the Basque Government Industry and Education Departments under the ELKARTEK and PIBA (PIBA-2018-06) programs, respectively.

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