**5. Conclusions**

The antibacterial synthetic dural substitute was successfully fabricated by incorporating cefazolin into ORC/PCL bilayered composite, which still had the physical and mechanical properties in the range of natural dura mater. Cefazolin released from ORC/PCL bilayered composite was found to be monophasic, comprising mainly a burst release. Among all formulations, P20\_25 might be most suitable since it showed relatively similar releasing profile and antibacterial activity to other higher drug loaded formulations and still exhibited comparable microstructure and physical and mechanical properties to the drug unloaded composite. Although cefazolin loaded ORC/PCL bilayered composite was found to exhibit a burst release of antibiotic, in which its antibacterial activity was sustained for up to 4 days, this might not fully predict in vivo performance where the environment and the clearance of the released cefazolin from the site of injury might be different. Further studies in animals are required to confirm its performance prior to translating to clinical study.

**Author Contributions:** Conceptualization, R.H. and J.S.; methodology, R.H. and J.S.; formal analysis, A.S., W.S., R.H. and J.S.; investigation, A.S. and W.S.; writing—original draft preparation, A.S., R.H. and J.S.; writing—review and editing, A.S., W.S., S.C., R.H. and J.S.; supervision, S.C., R.H. and J.S.; project administration, R.H. and J.S.; funding acquisition, A.S., R.H., S.C. and J.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** A.S. was financially supported by a scholarship from the Science Achievement Scholarship of Thailand. Collaborative research project grants from the Faculty of Science and the Faculty of Medicine Ramathibodi Hospital, Mahidol University and National Metal and Materials Technology Center (MTEC) are acknowledged for providing financial and technical support for carrying out this research.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to confidentiality.

**Acknowledgments:** Phetrung Phanpiriya (MTEC) is acknowledged for assistance in the antibacterial activity test.

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