We describe 3D printed poly lactic acid (PLA) bodies as scaffolds for hydrogel-calcium phosphate (CP)-hybrid materials for prospective application as biomaterial. The PLA was given a specific shape using fused deposition modelling (FDM) which in principle allows to create individualized implants for every patient.
A key step after printing is the surface modification of the PLA, to obtain several binding sites, e.g. to link a hydrogel on the surface. We used two different biopolymers, namely gelatin and chitosan, which where crosslinked with glutaraldehyde to form a hydrogel layer on the printed scaffold. During hydrogel formation, we also mineralized calcium phosphate on the surface, using a dip coating method, similar to the method described by Taguchi et al. 
Currently we are investigating different methods for surface modification e.g. binding of an alkyne function for further chemical modifications or the use of affinity tags for specific protein interactions with the surface.
Ref.  Schneider et al., Polymers, 2018, 10, 275
Ref.  Taguchi et al., Biomaterials, 2000, 22, 53