title: Nanocomposites of high-density polyethylene with amorphous calcium phosphate: in vitro biomineralization and cytocompatibility of human mesenchymal stem cells.
abstract: Polyethylene is widely used as a component of implants in medicine. Composites made of high-density polyethylene (HDPE) containing different amounts of amorphous calcium phosphate nanoparticles were investigated concerning their in vitro biomedical performance. The nanoparticles were produced by flame spray synthesis and extruded with HDPE, the latter complying with Food and Drug Administration regulations. Mechanical properties such as Young's modulus and contact angle as well as in vitro biomineralization of the nanocomposites hot-pressed into thin films were evaluated. The deposition of a hydroxyapatite layer occurred upon immersion in simulated body fluid. Additionally, a cell culture study with human mesenchymal stem cells for six weeks allowed a primary assessment of the cytocompatibility. Viability assays (alamarBlue and lactate dehydrogenase detection) proved the absence of cytotoxic effects of the scaffolds. Microscopic images after hematoxylin and eosin staining confirmed typical growth and morphology. A preliminary experiment analyzed the alkaline phosphatase activity after two weeks. These findings motivate further investigations on bioactive HDPE in bone tissue engineering.
authors.affiliation: Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Nora
authors.initials: N
authors.lastname: Hild
authors.forename: Roland
authors.initials: R
authors.lastname: Fuhrer
authors.forename: Dirk
authors.initials: D
authors.lastname: Mohn
authors.forename: Stephanie B
authors.initials: SB
authors.lastname: Bubenhofer
authors.forename: Robert N
authors.initials: RN
authors.lastname: Grass
authors.forename: Norman A
authors.initials: NA
authors.lastname: Luechinger
authors.forename: Kirill
authors.initials: K
authors.lastname: Feldman
authors.forename: Claudio
authors.initials: C
authors.lastname: Dora
authors.forename: Wendelin J
authors.initials: WJ
authors.lastname: Stark
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001031:Apatites / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry; D018786:Bone Substitutes / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry*; D002470:Cell Survival; D055119:Elastic Modulus; D006801:Humans; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000201:enzymology; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D020959:Polyethylene / Q000737:chemistry*; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; D018786:Bone Substitutes; D002130:Calcium Phosphates; C519480:amorphous calcium phosphate; D020959:Polyethylene; D000469:Alkaline Phosphatase