title: Hydroxyapatite scaffolds processed using a TBA-based freeze-gel casting/polymer sponge technique.
abstract: A novel freeze-gel casting/polymer sponge technique has been introduced to fabricate porous hydroxyapatite scaffolds with controlled "designer" pore structures and improved compressive strength for bone tissue engineering applications. Tertiary-butyl alcohol (TBA) was used as a solvent in this work. The merits of each production process, freeze casting, gel casting, and polymer sponge route were characterized by the sintered microstructure and mechanical strength. A reticulated structure with large pore size of 180-360 microm, which formed on burn-out of polyurethane foam, consisted of the strut with highly interconnected, unidirectional, long pore channels (approximately 4.5 microm in dia.) by evaporation of frozen TBA produced in freeze casting together with the dense inner walls with a few, isolated fine pores (<2 microm) by gel casting. The sintered porosity and pore size generally behaved in an opposite manner to the solid loading, i.e., a high solid loading gave low porosity and small pore size, and a thickening of the strut cross section, thus leading to higher compressive strengths.
authors.affiliation: School of Materials Science and Engineering, Pusan National University, Pusan, 609-735, South Korea.
authors.forename: Tae Young
authors.initials: TY
authors.lastname: Yang
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Seog Young
authors.initials: SY
authors.lastname: Yoon
authors.forename: Hong Chae
authors.initials: HC
authors.lastname: Park
mesh_terms: D001842:Bone and Bones; D019245:Compressive Strength; D017886:Durapatite / Q000737:chemistry*; D005615:Freezing; D005782:Gels; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D023822:Tissue Engineering / Q000379:methods; D020002:tert-Butyl Alcohol
chemical_list: D005782:Gels; D011108:Polymers; D017886:Durapatite; D020002:tert-Butyl Alcohol