Resorbable Fiber Meshes in Calcium Phosphate Cement for Short-Term Reinforcement and Macropore Channels
Hockin D. Xu, Janet Quinn
A water-based calcium phosphate cement (CPC) sets to form solid hydroxyapatite and has been used in a number of medical and dental procedures. However, due to its relatively low strength and susceptibility to catastrophic fracture, CPC is not recommended for stress-bearing applications. Building macropores into CPC suitable for vascular ingrowth further degraded its strength. The aim of the present study, therefore, was to use resorbable fiber meshes to strengthen CPC. A novel methodology was developed to combine reinforcement with macroporosity: stacked sheets of a resorbable fiber mesh were incorporated into CPC to provide the needed short-term strength, then dissolved to create interconnected macropore channels suitable for vascular ingrowth. A resorbable fiber mesh was cut to dimensions of 4 mm x 25 mm. The following numbers of meshes were placed into a stainless steel mold of 3 mm x 4 mm x 25 mm: 0, 1, 3, 6, and 13 (at which the stacked meshes reached the height of the mold). The CPC paste was placed into the mold filling the holes of the meshes and setting into a cohesive solid specimen. The specimens were immersed in a saline solution at 37 C for 1 d, 14 d, 21 d, 28 d, 42 d and 84 d, and were then tested in three-point flexure. SEM was used to examine crack-mesh interactions and macropore formation. CPC-mesh specimens achieved a flexural strength nearly three times, and work-of-fracture (toughness) two orders of magnitude, greater than unreinforced CPC. The strength and toughness were maintained for about 14-28 d of immersion. Interconnected macropore channels were observed in CPC-mesh composites after mesh dissolution. In conclusion, incorporating resorbable fiber meshes can achieve the needed short-term strength and toughness for CPC while tissue regeneration is occurring, then create interconnected macropore channels suitable for vascular ingrowth when the meshes dissolve. The reinforcement mechanisms appeared to be meshes bridging the cracks and mesh pullout.
and Quinn, J.
Resorbable Fiber Meshes in Calcium Phosphate Cement for Short-Term Reinforcement and Macropore Channels, Journal of Biomedical Materials Research, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851884
(Accessed December 8, 2023)