title: Novel scaffolds based on poly(2-hydroxyethyl methacrylate) superporous hydrogels for bone tissue engineering.
abstract: In this study, poly(2-hydroxyethyl methacrylate) (pHEMA)-based superporous hydrogels were synthesized by radical polymerization of 2-hydroxyethyl methacrylate (HEMA) in the presence of a gas blowing agent, sodium bicarbonate. These hydrogels are: pHEMA, pHEMA-gelatin, glycerol phosphate (GP) cross-linked pHEMA-gelatin, glutaraldehyde (GA) cross-linked pHEMA-gelatin superporous hydrogels (SPHs) and pHEMA-hydroxyapatite (HA) superporous hydrogel composites (SPHCs). The hydrogels have a structure of interconnected pores with pore sizes of approx. 500 μm. Although the extent of swelling decreased when gelatin and HA were incorporated to the pHEMA structure, the time to reach the equilibrium swelling (approx. 20 s) was not affected so much. In the presence of gelatin and cross-linkers, mechanical properties significantly improved when compared with pHEMA SPH. Among all the synthesized hydrogels, pHEMA-HA SPHC showed great improvement in mechanical strength and its elastic modulus value was 0.027±0.002 N/mm(2). Osteogenic activities of pHEMA-based scaffolds were examined by preosteoblastic MC3T3-E1 cell-culture studies. The mitochondrial activity test (MTT) showed that gelatin-containing scaffolds stimulated cell proliferation compared with other scaffolds, while alkaline phosphatase levels (ALP) and mineralization were found highest for the GP cross-linked pHEMA-gelatin SPH. However, pHEMA SPH and pHEMA-HA SPHC did not support cell proliferation and also differentiation. In conclusion, pHEMA-gelatin SPH and GP cross-linked pHEMA-gelatin SPH can be considered as potential scaffolds for bone tissue-engineering applications.
authors.affiliation: a Department of Chemical Engineering, Hacettepe University, Beytepe, Ankara 06800, Turkey.
authors.forename: Damla
authors.initials: D
authors.lastname: Çetin
authors.forename: A Sera
authors.initials: AS
authors.lastname: Kahraman
authors.forename: Menemşe
authors.initials: M
authors.lastname: Gümüşderelioğlu
mesh_terms: D016475:3T3 Cells; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000737:chemistry; D002113:Calcification, Physiologic; D049109:Cell Proliferation / Q000502:physiology; D017886:Durapatite / Q000138:chemical synthesis / Q000737:chemistry; D055119:Elastic Modulus; D005780:Gelatin / Q000138:chemical synthesis / Q000737:chemistry; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry; D008422:Materials Testing; D051379:Mice; D008855:Microscopy, Electron, Scanning; D008928:Mitochondria / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology; D011102:Polyhydroxyethyl Methacrylate / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D016062:Porosity; D017693:Sodium Bicarbonate / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D023822:Tissue Engineering / Q000295:instrumentation; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D018786:Bone Substitutes; D020100:Hydrogels; C000257:polyhydroxyethyl methacrylate hydrogels; D011102:Polyhydroxyethyl Methacrylate; D017693:Sodium Bicarbonate; D005780:Gelatin; D017886:Durapatite; D000469:Alkaline Phosphatase