title: Electrical stimulation modulates osteoblast proliferation and bone protein production through heparin-bioactivated conductive scaffolds.
abstract: Electrical fields are known to interact with human cells. This principle has been explored to regulate cellular activities for bone tissue regeneration. In this work, Saos-2 cells were cultured on conductive scaffolds made of biodegradable poly(L-lactide) and the heparin-containing, electrically conducting polypyrrole (PPy/HE) to study their reaction to electrical stimulation (ES) mediated through such scaffolds. Both the duration and intensity of ES enhanced cell proliferation, generating a unique electrical intensity and temporal "window" within which osteoblast proliferation was upmodulated in contrast to the downmodulation or ineffectiveness in other ES regions. The favourable ES intensity (200 mV/mm) was further investigated in terms of the gene activation and protein production of two important osteoblast markers characterised by extracellular matrix maturation and mineralisation, that is alkaline phosphatase (ALP) and osteocalcin (OC). Both genes were found activated and the relevant protein production increased significantly following ES. In contrast, ES in the down-modulation region (400 mV/mm) suppressed the production of both ALP and OC. This work demonstrated that important osteoblast markers can be modulated with specific ES parameters mediated through conductive polymer substrates, providing a unique strategy for bone tissue engineering.
authors.affiliation: College of Environment and Biotechnology, Chongqing Technology and Business University, Chongqing, China.
authors.forename: Shiyun
authors.initials: S
authors.lastname: Meng
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Rouabhia
authors.forename: Ze
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000469:Alkaline Phosphatase / Q000096:biosynthesis*; D001861:Bone Regeneration; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004558:Electric Stimulation; D006801:Humans; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism*; D015675:Osteocalcin / Q000096:biosynthesis*; D011091:Polyesters; D011108:Polymers; D011758:Pyrroles; D023822:Tissue Engineering / Q000379:methods*; D015854:Up-Regulation
chemical_list: D011091:Polyesters; D011108:Polymers; D011758:Pyrroles; D015675:Osteocalcin; C067635:polypyrrole; C033616:poly(lactide); D000469:Alkaline Phosphatase