The effect of poly (4-styrenesulfonic acid-co-maleic acid) sodium salt polyelectrolyte multilayer films to bone formation on titanium in vitro and in vivo study

Abstract

This study was to examine both in vitro and in vivo responses of osteoblast on titanium (Ti) coated with {(PDADMAC/PSS)4/PDADMAC}PSS-co-MA polyelectrolyte multilayer (PEM) films formed by poly(diallyldimethylammonium chloride) (PDADMAC), poly(sodium 4-styrene sulfonate) (PSS) and poly(4-styrenesulfonic acid-co-maleic acid)sodium salts (PSS-co-MA) to generate PEM films. In vitro study included the study of physical characteristics using scanning electron microscope, atomic force microscopy and contact angle measurement, respectively. Fibrin clot formations, utilizing whole blood dropped, on Ti were investigated. Gene expressions of MC3T3E1-osteoblast cells were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and in vitro calcifications were detected using alizarin red-S staining. Titanium pins were implanted into the Wistar rat femurs and new bone formations were confirmed by histomorphometric analysis. Results showed PSS-co-MA coated Ti surface had a better hydrophilic property however no change in surface roughness was detected compared to the control. The amount of fibrin formation on coated surface was higher than that on the control. The expressions of type-I collagen were significantly increased at day-5 while the expressions of osteopontin, bone sialoprotein and osteocalcin increased at day-10. Higher alizarin red-S staining was observed at day-15 on coated Ti compared to the control. The bone-to-implant contact around the coated Ti pins significantly increased compared to the control in the rats at 2 weeks. However, no significant differences in bone volume were observed among the different groups. In conclusions, modified Ti surface by PSS-co-MA PEM films accelerates the bone formations. This technique may be the candidate to improve dental implant surface for accelerating osseointegration.