Polycaprolactone with multiscale porosity and patterned surface topography prepared using sacrificial 3D printed moulds: Towards tailor-made scaffolds

Biocompatible three-dimensional porous scaffolds are widely used in multiple biomedical applications. However, the fabrication of tailor-made 3D structures with controlled and combined multiscale macroscopic-microscopic, surface and inner porosities in a straightforward manner is still a current challenge. Herein, we use multimaterial fused deposition modeling (FDM) to generate poly (vinyl alcohol) (PVA) sacrificial moulds filled with poly (Ɛ-caprolactone) (PCL) to generate well defined PCL 3D objects. Further on, the supercritical CO (SCCO) technique, as well as the breath figures mechanism (BFs), were additionally employed to fabricate specific porous structures at the core and surfaces of the 3D PCL object, respectively. The biocompatibility of the resulting multiporous 3D structures was tested in vitro and in vivo, and the versatility of the approach was assessed by generating a vertebra model fully tunable at multiple pore size levels. In sum, the combinatorial strategy to generate porous scaffolds offers unique possibilities to fabricate intricate structures by combining the advantages of additive manufacturing (AM), which provides flexibility and versatility to generate large sized 3D structures, with advantages of the SCCO and BFs techniques, which allow to finely tune the macro and micro porosity at material surface and material core levels.Grants RTI2018-101708-A-I00 and PID2021-127191OB-I00 funded by Ministerio de Ciencia e Innovación/AEI/10.13039/501100011033, WP7 SGL2103040 from the NextGenerationEU funds (PTI Salud Global) and by ERDF A way of making Europe. Grants RYC2018-025502-I and PRE2018-084542 funded by MCIN/AEI/10.13039/501100011033 and by ESF Investing in your future. Grant 0508/2019/0009 funded by Fomento de San Sebastian innovative talent programme. Grant MDM- 2017-0720 Maria de Maeztu Units of Excellence Program funded by the Spanish Research Agency. Grant KK-2019/00093 Elkartek program funded by Basque Government. Grant CICBMG_PhD_03_2021 funded by CICbiomaGUNE and Polymat. 2019 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation, grant number IN[19]_CMA_- BIO_0119. The BBVA Foundation accepts no responsibility for the opinions, statements and contents included, which are entirely the re- sponsibility of the authors. This publication used the ReDIB ICTS infrastructure at CIC biomaGUNE, Ministry for Science and Innovation (MCIN). The authors would also thank the support received from the Inter- disciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain and the Interdisciplinary Platform for Additive Manufacturing (FAB3D)