Surface modification of 3D-printed polycaprolactone (PCL) scaffolds for bone tissue engineering

The objective of bone tissue engineering (BTE) is to regenerate bone by combining biomaterials, cells, and bioactive substances. BTE scaffolds are infinitely available, non-immunogenic, and infection-free. They are also made to resemble the real bone in terms of cell composition, structure, and chemistry. Polycaprolactone (PCL), either by itself or in combination with other materials, is a popular biocompatible polymer used in the fused deposition modeling (FDM) process. Since PCL surfaces are hydrophobic and smooth, proper cell attachment upon implantation is compromised. Regeneration is seriously impeded by this constraint; hence, several researchers have worked on developing strategies for modifying PCL's surface to enhance cell adhesion. Techniques for surface modification include coatings that include hydrophilic or bioactive substances, chemical processes like alkaline etching, physical treatments like laser texturing, etc. The objective of the present study was to provide a summary of the surface modification approaches that have been examined and to evaluate the various methods, their assessments, and their claimed efficiency. This review presents significant results of the relevant literature, discussions on the obtained findings, and future research and clinical directions on the applications of various surface modification methods of 3D-printed PCL scaffolds for BTE.