title: A simultaneous process of 3D magnesium phosphate scaffold fabrication and bioactive substance loading for hard tissue regeneration.
abstract: 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.
authors.affiliation: Powder & Ceramics Division, Korea Institute of Materials Science (KIMS), 797 Changwondaero, Changwon 641-831, Republic of Korea.
authors.forename: Jongman
authors.initials: J
authors.lastname: Lee
authors.affiliation: Powder & Ceramics Division, Korea Institute of Materials Science (KIMS), 797 Changwondaero, Changwon 641-831, Republic of Korea; Biomaterials Department, National Research Centre (NRC), 33 El-Bohooth St, Dokki 12622, Egypt.
authors.forename: Mohammad Mahmoud
authors.initials: MM
authors.lastname: Farag
authors.affiliation: School of Dentistry, Kyungpook National University, Daegu 700-422, Republic of Korea.
authors.forename: Eui Kyun
authors.initials: EK
authors.lastname: Park
authors.affiliation: School of Dentistry, Kyungpook National University, Daegu 700-422, Republic of Korea.
authors.forename: Jiwon
authors.initials: J
authors.lastname: Lim
authors.affiliation: Powder & Ceramics Division, Korea Institute of Materials Science (KIMS), 797 Changwondaero, Changwon 641-831, Republic of Korea. Electronic address: yuni@kims.re.kr.
authors.forename: Hui-Suk
authors.initials: HS
authors.lastname: Yun
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002516:Ceramics / Q000737:chemistry; D007700:Kinetics; D017616:Magnesium Compounds / Q000494:pharmacology*; D055595:Mechanical Phenomena / Q000187:drug effects; D051379:Mice; D009113:Muramidase / Q000494:pharmacology; D010012:Osteogenesis / Q000187:drug effects; D010710:Phosphates / Q000494:pharmacology*; D011208:Powders; D060888:Real-Time Polymerase Chain Reaction; D012038:Regeneration / Q000187:drug effects*; D017550:Spectroscopy, Fourier Transform Infrared; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D017616:Magnesium Compounds; D010710:Phosphates; D011208:Powders; C030781:magnesium phosphate; D009113:Muramidase
keywords: Bone scaffold; Direct drug loading; Magnesium phosphate; Paste extruding deposition; Room temperature fabrication