title: In vitro behavior of a porous TiO2/perlite composite and its surface modification with fibronectin.
abstract: In this study, we introduce a porous composite material, termed "Ecopore", and describe in vitro investigation of the material and its modification with fibronectin. The material is a sintered compound of rutile TiO2 and the volcanic silicate perlite with a macrostructure of interconnecting pores. It is both inexpensive and easy to manufacture. We first investigated Ecopore for corrosion and leaching of elements in physiological saline. The corrosion supernatants did not contain critical concentrations of toxic trace elements. In an in vitro model, human primary osteoblasts (HOB) were cultured directly on Ecopore. HOB grew on the composite as well as on samples of its single constituents, TiO2 and perlite glass, and remained vital, but cellular spreading was less than on tissue culture plastic. The pro-inflammatory cytokines IL-1 and TNF-alpha were below detection limits in HOB culture supernatants, whereas IL-6 was detectable on a low level. To enhance cellular attachment and growth, the surface of the composite was modified by etching, functionalization with aminosilane and coupling of fibronectin. This modification greatly enhanced the spreading of HOB, indicated by vital staining and Sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis (4-methoxy-6-nitro) benzene sulfonic acid hydrate (XTT) metabolism assays. HOB grew on the entire visible surface of porous fibronectin-modified composite, expressing alkaline phosphatase, a mature osteoblast marker. We conclude that Ecopore is non-toxic and sustains HOB growth, cellular spreading being improvable by coating with fibronectin. The composite may be usable in the field of bone substitution.
authors.affiliation: Clinic of Trauma Surgery, RWTH University of Aachen, Pauwelsstr. 30, 52074 Aachen, Germany. mvwalter@gmx.de
authors.forename: Matthias
authors.initials: M
authors.lastname: von Walter
authors.forename: Matthias
authors.initials: M
authors.lastname: Rüger
authors.forename: Christian
authors.initials: C
authors.lastname: Ragoss
authors.forename: Guy C M
authors.initials: GC
authors.lastname: Steffens
authors.forename: Dirk A
authors.initials: DA
authors.lastname: Hollander
authors.forename: Othmar
authors.initials: O
authors.lastname: Paar
authors.forename: Horst R
authors.initials: HR
authors.lastname: Maier
authors.forename: Willi
authors.initials: W
authors.lastname: Jahnen-Dechent
authors.forename: Anja K
authors.initials: AK
authors.lastname: Bosserhoff
authors.forename: Hans-Josef
authors.initials: HJ
authors.lastname: Erli
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000537:Aluminum Oxide / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods; D002470:Cell Survival; D002516:Ceramics / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D005353:Fibronectins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007202:Indicators and Reagents / Q000494:pharmacology; D007249:Inflammation; D007375:Interleukin-1 / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D010006:Osteoblasts / Q000378:metabolism; D017640:Silicates / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry* / Q000494:pharmacology*; D012965:Sodium Chloride / Q000737:chemistry; D013499:Surface Properties; D013778:Tetrazolium Salts / Q000494:pharmacology; D014025:Titanium / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D016207:Cytokines; C501585:Ecopore; D005353:Fibronectins; D007202:Indicators and Reagents; D007375:Interleukin-1; D017640:Silicates; D013778:Tetrazolium Salts; D014409:Tumor Necrosis Factor-alpha; C003076:Perlite; C059087:2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide; C009495:titanium dioxide; D012965:Sodium Chloride; D012822:Silicon Dioxide; D014025:Titanium; D000469:Alkaline Phosphatase; D000537:Aluminum Oxide