title: Interfacial pH: a critical factor for osteoporotic bone regeneration.
abstract: Osteoporosis is a disease attributed to an imbalance in communication between osteoblasts and osteoclasts, possibly arising from a locally acidic microenvironment which hinders normal cell function. However, to date, little or no attention has been paid to these cells' milieu in respect of implant materials. Although it has been claimed for a few biomaterials that they stimulate bone formation, seldom has their surface behavior been invoked to explain behavior. With degradation, ion concentrations and pH at the material's surface must vary and thus may affect osteoblast response directly. On degradation of a recently developed biomaterial, Sr-containing CaSiO3, the interfacial pH was found to be appreciably higher than that of the bulk medium and the "standard" physiological value of 7.4. At these high values (pH > 8), both the proliferation and alkaline phosphatase (ALP) activity of osteoblasts was significantly enhanced, with a maximum response at 10% Sr substitution for Ca. This shows that the chemistry of the solid-liquid interface is a critical factor in bone regeneration, although this has generally been overlooked. Thus, the interfacial pH in particular is to be considered, rather than the bulk value, and this may be of importance in many related contexts in bone-tissue engineering.
authors.affiliation: Department of Orthopaedics, Shanghai Institute of Orthopaedics & Traumatology, Shanghai Ruijin Hospital, Shanghai Jiaotong University School of Medicine , China.
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Shen
authors.forename: Waiching
authors.initials: W
authors.lastname: Liu
authors.forename: Kaili
authors.initials: K
authors.lastname: Lin
authors.forename: Haobo
authors.initials: H
authors.lastname: Pan
authors.forename: Brian W
authors.initials: BW
authors.lastname: Darvell
authors.forename: Songlin
authors.initials: S
authors.lastname: Peng
authors.forename: Chunyi
authors.initials: C
authors.lastname: Wen
authors.forename: Lianfu
authors.initials: L
authors.lastname: Deng
authors.forename: William W
authors.initials: WW
authors.lastname: Lu
authors.forename: Jiang
authors.initials: J
authors.lastname: Chang
mesh_terms: D001861:Bone Regeneration; D017610:Calcium Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D017640:Silicates / Q000737:chemistry
chemical_list: D017610:Calcium Compounds; D017640:Silicates; C031293:calcium silicate