Enhanced cell adhesion on bioinert ceramics mediated by the osteogenic cell membrane enzyme alkaline phosphatase.
Functional bone and dental implant materials are required to guide cell response, offering cues that provide specific instructions to cells at the implant/tissue interface while maintaining full biocompatibility as well as the desired structural requirements and functions. In this work we investigate the influence of covalently immobilized alkaline phosphatase (ALP), an enzyme involved in bone mineralization, on the first contact and initial cell adhesion. To this end, ALP is covalently immobilized by carbodiimide-mediated chemoligation on two highly bioinert ceramics, alpha-alumina (Al2O3) and yttria-stabilized zirconia (Y-TZP) that are well-established for load-bearing applications. The physicochemical surface properties are evaluated by profilometry, zeta potential and water contact angle measurements. The initial cell adhesion of human osteoblasts (HOBs), human osteoblast-like cells (MG-63) and mesenchymal stromal cells (hMSCs) was investigated. Cell adhesion was assessed at serum free condition via quantification of percentage of adherent cells, adhesion area and staining of the focal adhesion protein vinculin. Our findings show that after ALP immobilization, the Al2O3 and Y-TZP surfaces gained a negative charge and their hydrophilicity was increased. In the presence of surface-immobilized ALP, a higher cell adhesion, more pronounced cell spreading and a higher number of focal contact points were found. Thereby, this work gives evidence that surface functionalization with ALP can be utilized to modify inert materials for biological conversion and faster bone regeneration on inert and potentially load-bearing implant materials.
Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
Alieh
A
Aminian
Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
Bahareh
B
Shirzadi
Islet Biology Laboratory, Centre for Biomolecular Interactions, University of Bremen, Bibliothekstrasse 1, 28359 Bremen, Germany.
Zahra
Z
Azizi
Islet Biology Laboratory, Centre for Biomolecular Interactions, University of Bremen, Bibliothekstrasse 1, 28359 Bremen, Germany.
Kathrin
K
Maedler
Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
Eike
E
Volkmann
Hybrid Materials Interfaces Group, Faculty of Production Engineering University of Bremen, 28359 Bremen, Germany.
Nils
N
Hildebrand
Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany; MAPEX Center for Materials and Processes, University of Bremen, 28359 Bremen, Germany.
Michael
M
Maas
Petroceramics S.p.A., c/o Kilometro Rosso Science and Technology Park, Viale Europa 2, 24040 Stezzano, Italy. Electronic address: treccanilaura@gmail.com.
Laura
L
Treccani
Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany; MAPEX Center for Materials and Processes, University of Bremen, 28359 Bremen, Germany.
Kurosch
K
Rezwan
D000469:Alkaline Phosphatase / Q000737:chemistry / Q000378:metabolism*; D000537:Aluminum Oxide / Q000737:chemistry; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism*; D002516:Ceramics / Q000737:chemistry* / Q000494:pharmacology; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008856:Microscopy, Fluorescence; D013499:Surface Properties; D017155:Wettability; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
D004800:Enzymes, Immobilized; D015019:Yttrium; D015040:Zirconium; D000469:Alkaline Phosphatase; D000537:Aluminum Oxide; C028541:zirconium oxide; C091417:yttria
Alkaline phosphatase; Alumina; Bioinert; Biomineralization; Focal points; Initial cell adhesion; Vinculin; Yttria-stabilized zirconia