A simultaneous process of 3D magnesium phosphate scaffold fabrication and bioactive substance loading for hard tissue regeneration

• Published in: Materials Science & Engineering C 2014-03, Vol.36, p.252-260
• Main Authors: Lee, Jongman, Farag, Mohammad Mahmoud, Park, Eui Kyun, Lim, Jiwon, Yun, Hui-suk
• Format: Article
• Language: English
• Subjects: Animals; Biocompatibility; Biocompatible Materials - pharmacology; Bone scaffold; Cell Differentiation - drug effects; Cell Line; Cell Proliferation - drug effects; Cements; Ceramics - chemistry; Direct drug loading; Drugs; Extruding; Kinetics; Magnesium Compounds - pharmacology; Magnesium phosphate; Mechanical Phenomena - drug effects; Mice; Muramidase - pharmacology; Osteogenesis - drug effects; Paste extruding deposition; Phosphates - pharmacology; Powders; Real-Time Polymerase Chain Reaction; Regeneration; Regeneration - drug effects; Room temperature fabrication; Scaffolds; Sintering (powder metallurgy); Spectroscopy, Fourier Transform Infrared; Three dimensional; Tissue Engineering - methods; Tissue Scaffolds - chemistry; X-Ray Diffraction
• ISSN: 0928-4931; 1873-0191
• DOI: 10.1016/j.msec.2013.12.007

A novel room temperature process was developed to produce a 3D porous magnesium phosphate (MgP) scaffold with high drug load/release efficiency for use in hard tissue regeneration through a combination of a paste extruding deposition (PED) system and cement chemistry. MgP scaffolds were prepared using a two-step process. The first step was fabrication of the 3D porous scaffold green body to control both the morphology and pore structure using a PED system without hardening. The second step was cementation, which was carried out by immersing the scaffold green body in the binder solution for hardening instead of the typical sintering process in ceramic scaffold fabrication. Separation of the manufacturing process and cement reaction was important to secure enough time to fabricate a 3D scaffold with various sizes and architectures under homogeneous extruding conditions. Because the whole process is carried out at room temperature, the bioactive molecules, which are easily denatured by heat, may apply to scaffolds during the process. Lysozyme was selected as a model bioactive substance to demonstrate the efficiency of this process; this was directly mixed into MgP powder to introduce homogeneous distribution in the scaffold. The extruding paste for the PED system was prepared using the MgP–lysozyme blended powder as starting materials. That is, both 3D scaffold fabrication and functionalization of the scaffold with bioactive substances could be carried out simultaneously. This process significantly enhanced both drug loading efficiency and release performance compared to the typical sintering process, where the drug is generally loaded by adsorption after heat treatment. The MgP scaffold developed in this study satisfied the required conditions for scaffolding in hard tissue regeneration in an ideal manner, including 3 dimensionally well-interconnected pore structures, favorable mechanical properties, biodegradability, good cell affinity and in vitro biocompatibility; thus, it has excellent potential for application in the field of biomaterials. A novel room temperature process was developed to produce a 3D porous magnesium phosphate (MgP) scaffold with high drug load/release efficiency for bone tissue regeneration, using a combination of a paste extruding deposition (PED) system and cement chemistry. [Display omitted] •3D porous MgP scaffolds were prepared by novel two step room temperature fabrication.•Paste extruding deposition system was applied for fabr