title: Short-term administration of small molecule phenamil induced a protracted osteogenic effect on osteoblast-like MC3T3-E1 cells.
abstract: Sustained administration (21-day treatment) of the small molecule phenamil has been proposed as an alternative osteogenic factor when used in conjunction with a biodegradable scaffold for in vitro osteogenesis. While promising, the major issue associated with small molecules is non-specific cytotoxicity. The aim of this study was to minimize the side-effects from small-molecule drugs by reducing the frequency of administration. Toward this goal, we investigated whether a shorter phenamil treatment is sufficient to induce in vitro osteogenesis. We compared the effects of short-term (12 h) and continuous treatments of phenamil on osteoblastic differentiation and mineralization. Alkaline phosphatase (ALP) and osteopontin (OPN) activity were used as markers for osteoblastic differentiation. Measurement of the calcium content of the extracellular matrix was used as the hallmark for in vitro bone formation after 21 days of culture. Our findings revealed that both short and continuous phenamil treatment triggers osteoblastic differentiation and mineralization of MC3T3-E1 cells on a biodegradable polymeric scaffold composed of polylactic-co-glycolic acid (PLAGA) at the same time points. In addition, in order to fabricate a phenamil-loaded PLAGA scaffold, the small molecule phenamil was physically absorbed onto the surface of scaffolds and the bioactivity of the loaded scaffolds was evaluated. Furthermore, biochemical analysis indicated that short phenamil treatment of cells was accompanied by upregulation in protein expression of integrin α5, p125(FAK) and phosphorylation of CREB. These effects may contribute to the downstream signalling cascade necessary for osteogenesis, and such responses may account for our observed protracted osteogenic differentiation in vitro. Copyright © 2013 John Wiley & Sons, Ltd.
authors.affiliation: Institute for Regenerative Engineering, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.|The Raymond and Beverly Sackler Center for Biomedical, Biological, Physical and Engineering Sciences, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.|Department of Medicine, Division of Endocrinology, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.|Department of Biomedical Engineering, University of Connecticut, School of Engineering, Storrs, CT, USA.
authors.forename: Kevin W-H
authors.initials: KW
authors.lastname: Lo
authors.affiliation: Department of Orthopedic Surgery, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.|Institute for Regenerative Engineering, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.|The Raymond and Beverly Sackler Center for Biomedical, Biological, Physical and Engineering Sciences, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.
authors.forename: Ho Man
authors.initials: HM
authors.lastname: Kan
authors.affiliation: Department of Orthopedic Surgery, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.|Institute for Regenerative Engineering, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.|The Raymond and Beverly Sackler Center for Biomedical, Biological, Physical and Engineering Sciences, University of Connecticut Health Center, School of Medicine, Farmington, CT, USA.|Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, School of Engineering, Storrs, CT, USA.|Department of Biomedical Engineering, University of Connecticut, School of Engineering, Storrs, CT, USA.
authors.forename: Cato T
authors.initials: CT
authors.lastname: Laurencin
mesh_terms: D000584:Amiloride / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D004337:Drug Carriers / Q000737:chemistry / Q000494:pharmacology; D019344:Lactic Acid / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis / Q000187:drug effects*; D011100:Polyglycolic Acid / Q000737:chemistry / Q000494:pharmacology; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer
chemical_list: D000943:Antigens, Differentiation; D004337:Drug Carriers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; C047088:phenylamil; D011100:Polyglycolic Acid; D019344:Lactic Acid; D000584:Amiloride
keywords: biomaterials; cell adhesion; growth factors; osteogenesis; regenerative engineering; small molecules