title: Preparation of PLGA scaffolds with graded pores by using a gelatin-microsphere template as porogen.
abstract: Porous scaffolds with graded pores are crucial to osteochondral regeneration. In this study, a technique combining solution casting with gelatin-microsphere template leaching has been developed to produce poly(L-lactide-co-glycolide) (PLGA) scaffolds with graded pores. The traditional emulsification and solvent extraction method was improved by using the gradient ethanol/water solutions to extract water to prepare gelatin microspheres with a smooth surface without the use of any surfactant. Gelatin microspheres with different diameters were in sequence put into a custom-made cylindrical Teflon mold and bonded together to obtain gelatin-microsphere templates. By using the gelatin-microsphere templates as porogen, PLGA scaffolds with graded pore size across the cylindrical axis were prepared. The porosity of the scaffold was as high as 95%. The pore size effect on osteoblasts was studied. The results showed that the graded scaffolds possessed good biocompatibility for osteoblast growth. During the 14 days culture, the cell proliferation of all the three pore layers displayed the trend of increasing. The proliferation rate of the large pore layer was lower than the other two layers. However, the difference of alkaline phosphatase activity on the three pore layers was not statistically significant. We assumed that it was probably because of the hydrophobicity and the short culture time. It was demonstrated that gradient ethanol/water solutions provided a simple way to prepared gelatin microspheres. The graded scaffolds would provide potential application for osteochondral regeneration.
authors.affiliation: a School of Materials Science and Engineering, and Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University , Tianjin , 300072 , P. R. China.
authors.forename: Gongwen
authors.initials: G
authors.lastname: Tang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiulan
authors.initials: X
authors.lastname: Li
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yuan
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000138:chemical synthesis* / Q000737:chemistry; D049109:Cell Proliferation; D002478:Cells, Cultured; D000431:Ethanol / Q000737:chemistry; D005780:Gelatin / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D019344:Lactic Acid / Q000737:chemistry; D008422:Materials Testing; D008863:Microspheres; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D016062:Porosity; D017207:Rats, Sprague-Dawley; D012886:Skull / Q000166:cytology / Q000502:physiology; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D018786:Bone Substitutes; D014867:Water; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D000431:Ethanol; D005780:Gelatin; D000469:Alkaline Phosphatase