title: Characterization of the physical properties and biocompatibility of polybenzoxazine-based aerogels for use as a novel hard-tissue scaffold.
abstract: The process to successfully synthesize polybenzoxazine (PBO)-based aerogels has recently been optimized; however, the biocompatibility of these materials has never been investigated. PBO is synthesized from bisphenol A and aniline, which are both precursors to many commonly used biomaterials, including polyurethane. Surface-wise these new aerogels resemble the innate extracellular matrix of bone and if these new aerogels exhibit acceptable biocompatibility, they may be used as a scaffold for bone tissue engineering. Here, we aimed to characterize some of the physical properties of PBO aerogels, PBO aerogels co-polymerized with resorcinol and formaldehyde (RF) and their conversion to carbon aerogel, while determining the compatibility of all of these materials towards human osteoblasts. Biocompatibility was determined with a live/dead cell cytotoxicity assay, a metabolic activity assay, alkaline phosphatase activity and osteocalcin production, after incubation with PBO-based aerogels for up to 5 days. PBO aerogels co-polymerized with RF tended to have a low density, porosity and elastic modulus and provided the weakest substrate for bone cell growth. PBO-derived carbon aerogels tended to have a high density, a large porosity and improved mechanical properties and provided the best substrate for bone cell growth. These results suggest that PBO based carbon aerogels have a suitable biocompatibility towards osteoblasts and that they may be able to be used for bone tissue engineering scaffolds.
authors.affiliation: a School of Mechanical and Aerospace Engineering, Oklahoma State University , Stillwater , OK , 74078 , USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Rubenstein
authors.forename: Hongbing
authors.initials: H
authors.lastname: Lu
authors.forename: Shruti S
authors.initials: SS
authors.lastname: Mahadik
authors.forename: Nicholas
authors.initials: N
authors.lastname: Leventis
authors.forename: Wei
authors.initials: W
authors.lastname: Yin
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000814:Aniline Compounds / Q000737:chemistry; D001559:Benzhydryl Compounds / Q000737:chemistry; D048588:Benzoxazines / Q000138:chemical synthesis / Q000737:chemistry*; D018786:Bone Substitutes / Q000138:chemical synthesis / Q000737:chemistry*; D016923:Cell Death; D049109:Cell Proliferation; D002478:Cells, Cultured; D055119:Elastic Modulus; D005557:Formaldehyde / Q000737:chemistry; D005782:Gels / Q000138:chemical synthesis / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D010006:Osteoblasts / Q000502:physiology; D015675:Osteocalcin / Q000378:metabolism; D010636:Phenols / Q000737:chemistry; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D016062:Porosity; D012118:Resorcinols / Q000138:chemical synthesis / Q000737:chemistry; D012886:Skull / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*; D000098826:Bisphenol A Compounds
chemical_list: D000469:Alkaline Phosphatase; D000814:Aniline Compounds; D001559:Benzhydryl Compounds; D048588:Benzoxazines; D018786:Bone Substitutes; D005557:Formaldehyde; D005782:Gels; D015675:Osteocalcin; D010636:Phenols; D011108:Polymers; D012118:Resorcinols; C006780:bisphenol A; D000098826:Bisphenol A Compounds; C023650:aniline; C031389:resorcinol