title: Biocompatibility of Polypyrrole with Human Primary Osteoblasts and the Effect of Dopants.
abstract: Polypyrrole (PPy) is a conducting polymer that enables controlled drug release upon electrical stimulation. We characterized the biocompatibility of PPy with human primary osteoblasts, and the effect of dopants. We investigated the biocompatibility of PPy comprising various dopants, i.e. p-toluene sulfonate (PPy-pTS), chondroitin sulfate (PPy-CS), or dodecylbenzenesulfonate (PPy-DBS), with human primary osteoblasts. PPy-DBS showed the roughest appearance of all surfaces tested, and its wettability was similar to the gold-coated control. The average number of attached cells was 45% higher on PPy-DBS than on PPy-CS or PPy-pTS, although gene expression of the proliferation marker Ki-67 was similar in osteoblasts on all surfaces tested. Osteoblasts seeded on PPy-DBS or gold showed similar vinculin attachment points, vinculin area per cell area, actin filament structure, and Feret's diameter, while cells seeded on PPY-CS or PPY-pTS showed disturbed focal adhesions and were enlarged with disorganized actin filaments. Osteoblasts grown on PPy-DBS or gold showed enhanced alkaline phosphatase activity and osteocalcin gene expression, but reduced osteopontin gene expression compared to cells grown on PPy-pTS and PPy-CS. In conclusion, PPy doped with DBS showed excellent biocompatibility, which resulted in maintaining focal adhesions, cell morphology, cell number, alkaline phosphatase activity, and osteocalcin gene expression. Taken together, conducting polymers doped with DBS are well tolerated by osteoblasts. Our results could provide a basis for the development of novel orthopedic or dental implants with controlled release of antibiotics and pharmaceutics that fight infections or focally enhance bone formation in a tightly controlled manner.
authors.affiliation: Department of Clinical and Experimental Medicine, Division of Orthopaedics, Linköping University, Linköping, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Fahlgren
authors.affiliation: Department of Clinical and Experimental Medicine, Division of Orthopaedics, Linköping University, Linköping, Sweden.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Bratengeier
authors.affiliation: Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics Centre, Linköping University, Linköping, Sweden.
authors.forename: Amy
authors.initials: A
authors.lastname: Gelmi
authors.affiliation: Department of Oral Cell Biology, ACTA-University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands.
authors.forename: Cornelis M
authors.initials: CM
authors.lastname: Semeins
authors.affiliation: Department of Oral Cell Biology, ACTA-University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jenneke
authors.initials: J
authors.lastname: Klein-Nulend
authors.affiliation: Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics Centre, Linköping University, Linköping, Sweden.
authors.forename: Edwin W H
authors.initials: EW
authors.lastname: Jager
authors.affiliation: Department of Oral Cell Biology, ACTA-University of Amsterdam and VU University Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands.
authors.forename: Astrid D
authors.initials: AD
authors.lastname: Bakker
mesh_terms: D001672:Biocompatible Materials; D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D011108:Polymers / Q000494:pharmacology*; D011758:Pyrroles / Q000494:pharmacology*; D013499:Surface Properties; D017155:Wettability
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole