Fabrication of calcium phosphate–calcium sulfate injectable bone substitute using hydroxy-propyl-methyl-cellulose and citric acid

Abstract

In this study, an injectable bone substitute (IBS) consisting of citric acid, chitosan, and hydroxyl propyl methyl cellulose (HPMC) as the liquid phase and tetra calcium phosphate (TTCP), dicalcium phosphate dihydrate (DCPD) and calcium sulfate dehydrate (CSD, CaSO4·2H2O) powders as the solid phase, were fabricated. Two groups were classified based on the percent of citric acid in the liquid phase (20, 40 wt%). In each groups, the HPMC percentage was 0, 2, and 4 wt%. An increase in compressive strength due to changes in morphology was confirmed by scanning electron microscopy images. A good conversion rate of HAp at 20% citric acid was observed in the XRD profiles. In addition, HPMC was not obviously affected by apatite formation. However, both HPMC and citric acid increased the compressive strength of IBS. The maximum compressive strength for IBS was with 40% citric acid and 4% HPMC after 14 days of incubation in 100% humidity at 37°C.

Calcium Orthophosphate-Containing Biocomposites and Hybrid Biomaterials for Biomedical Applications

“…They represent ready-to-use suspensions of CaPO 4 microspheres [ 818 , 819 ], nano-sized rods [ 820 ] or powder(s) in a liquid carrier phase. However, addition of other phases, such as calcium sulfate [ 821 ], is possible. IBS look like opaque viscous pastes with the rheological properties, sufficient to inject them into bone defects by means of surgical syringes and needles.…”

Biocomposites and hybrid biomaterials based on calcium orthophosphates

“…They represent ready-to-use suspensions of calcium orthophosphate microspheres, 888,889 nano-sized rods 890 or powder(s) in a liquid carrier phase. However, addition of other phases, such as calcium sulfate, 891 is also possible. They look like opaque viscous pastes with rheological properties sufficient to inject them into bone defects by means of surgical syringes and needles.…”

Rheological and Mechanical Properties of Thermoresponsive Methylcellulose/Calcium Phosphate-Based Injectable Bone Substitutes

“…Two of the most commonly used bioceramics for the production of CPCs are dicalcium phosphate dihydrate (DCPD, CaHPO 4 .2H 2 O) and tetra-calcium phosphate (TTCP, Ca 4 (PO 4 ) 2 O) [ 4 , 6 , 7 ]. After a mixture of TTCP and DCPD is injected into the defect site, it transforms into hydroxyapatite (HA) [ 6 , 7 , 8 , 9 ]. Pure CPC bone substitutes have many drawbacks; such as the possibility of collapse under physiological conditions, poor degradability, as well as weak torsional and bending strength [ 10 , 11 , 12 ].…”