Poly­(vinylphosphonic acid-co-acrylic acid) (PVPA-co-AA) has recently been identified as a possible candidate for use in bone tissue engineering. It is hypothesized that the strong binding of PVPA-co-AA to calcium in natural bone inhibits osteoclast activity. The free radical polymerization of acrylic acid (AA) with vinylphosphonic acid (VPA) has been investigated with varying experimental conditions. A range of copolymers were successfully produced and their compositions were determined quantitatively using 31P NMR spectroscopy. Monomer conversions were calculated using 1H NMR spectroscopy and a general decrease was found with increasing VPA content. Titration studies demonstrated an increase in the degree of dissociation as a function of VPA in the copolymer. However, a VPA content ca. 30 mol % was found to be the optimum for calcium chelation, suggesting that this composition is the most promising for biomaterials applications. Assessment of cell metabolic activity showed that PVPA-co-AA has no detrimental effect on cells, regardless of copolymer composition.

There is a clear clinical need for a bioactive bone graft substitute. Poly(vinyl phosphonic acid‐co‐acrylic acid) (PVPA‐co‐AA) has been identified as a promising candidate for bone regeneration but there is little evidence to show its direct osteogenic effect on progenitor or mature cells. In this study mature osteoblast‐like cells (SaOS‐2) and human bone marrow‐derived mesenchymal stem cells (hBM‐MSCs) were cultured with PVPA‐co‐AA polymers with different VPA:AA ratio and at different concentrations in vitro. We are the first to report the direct osteogenic effect of PVPA‐co‐AA polymer on bone cells and, more importantly, this effect was dependent on VPA:AA ratio and concentration. Under the optimized conditions, PVPA‐co‐AA polymer not only has an osteoconductive effect, enhancing SaOS‐2 cell mineralization, but also has an osteoinductive effect to promote hBM‐MSCs’ osteogenic differentiation. Notably, the same PVPA‐co‐AA polymer at different concentrations could lead to differential osteogenic effects on both SaOS‐2 and hBM‐MSCs in vitro. This study furthers knowledge of the PVPA‐co‐AA polymer in osteogenic studies, which is critical when utilizing the PVPA‐co‐AA polymer for the design of novel bioactive polymeric tissue engineering scaffolds for future clinical applications. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 168–179, 2018.