Injectable, Non‐Diffusible, and Pre‐Filled Bone Paste Composed of α‐Tricalcium Phosphate and Hydrophobically Modified Poly(Vinyl Alcohol)

Abstract

Herein, injectable, non‐diffusible, and pre‐filled bone pastes are developed using α‐tricalcium phosphate (α‐TCP) and hydrophobically modified poly(vinyl alcohol)s (hm‐PVAs) with various alkyl chain lengths (3–12). The resulting bone pastes show high injectability (over 90%) when the solid–liquid ratio is lower than 3.5. The non‐diffusion property of α‐TCP/hm‐PVAs bone pastes in water and fresh porcine blood is observed compared with α‐TCP alone, α‐TCP/original PVA (Org‐PVA), and commercial calcium phosphate paste. The compressive strength of α‐TCP/nonanal‐modified PVA (C9‐PVA) bone pastes is 5.4 ± 1.4 MPa within 24 h and reaches 27.5 ± 2.7 MPa after 7 days in water. Young's modulus of α‐TCP/C9‐PVA bone pastes is 0.84 ± 0.02 GPa, which is lower than that of commercial calcium phosphate paste (1.5 ± 0.02 GPa) and poly(methyl methacrylate)‐based bone cement (1.06 ± 0.03 GPa). Furthermore, the surface of α‐TCP/C9‐PVA bone pastes shows excellent cell adhesion of cultured osteoblastic cells. These results demonstrate that α‐TCP/C9‐PVA bone paste is a promising bone filler for percutaneous vertebroplasty (PVP) surgery.