Porous materials, modification of their surface and their application in graded implant development

(Bio)chemical modification of implants with drug delivery systems can support the body’s natural healing capabilities by imitation of smooth tissue transitions along bone-tendon conjunctions. Modified interconnected 3D porous poly(ε-caprolactone) could act as a scaffold material for these implants.
Cocontinuous blends of poly(ε-caprolactone) (PCL) and polyethylene oxide (PEO) can be prepared by batch blending in an internal mixer. Annealing and leaching of the blends with water yield the porous PCL scaffolds, which can then be modified with chitosan (CS) grafted PCL (CS-g-PCL) via dip coating. Several other blend ingredients and compositions are imaginable, opening manifold possibilities for different substrate morphologies and attributes. These porous scaffolds can then be modified with nanoparticle systems. For example, systems out of CS and tripolyphosphate (TPP) which can be obtained via ionotropic gelation. These CS-TPP nanoparticles (CSNPs) can be attached to the modified scaffolds via a Layer-by-Layer (LbL) deposition approach involving alginate (ALG). Loading these nanoparticles, with active pharmaceutical agents for example, could then help the damaged tissue to heal faster than in a passive-only approach.