Injectable calcium sulfate/mineralized collagen‐based bone repair materials with regulable self‐setting properties

Abstract

An injectable and self-setting bone repair materials (nano-hydroxyapatite/collagen/calcium sulfate hemihydrate, nHAC/CSH) was developed in this study. The nano-hydroxyapatite/collagen (nHAC) composite, which is the mineralized fibril by self-assembly of nano-hydrocyapatite and collagen, has the same features as natural bone in both main hierarchical microstructure and composition. It is a bioactive osteoconductor due to its high level of biocompatibility and appropriate degradation rate. However, this material lacks handling characteristics because of its particle or solid-preformed block shape. Herein, calcium sulfate hemihydrate (CSH) was introduced into nHAC to prepare an injectable and self-setting in situ bone repair materials. The morphology of materials was observed using SEM. Most important and interesting of all, calcium sulfate dihydrate (CSD), which is not only the reactant of preparing CSH but also the final solidified product of CSH, was introduced into nHAC as setting accelerator to regulate self-setting properties of injectable nHAC/CSH composite, and thus the self-setting time of nHAC/CSH composite can be regulated from more than 100 min to about 30 min and even less than 20 min by adding various amount of setting accelerator. The compressive properties of bone graft substitute after final setting are similar to those of cancellous bone. CSD as an excellent setting accelerator has no significant effect on the mechanical property and degradability of bone repair materials. In vitro biocompatibility and in vivo histology studies demonstrated that the nHAC/CSH composite could provide more adequate stimulus for cell adhesion and proliferation, embodying favorable cell biocompatibility and a strong ability to accelerate bone formation. It can offer a satisfactory biological environment for growing new bone in the implants and for stimulating bone formation.

Calcium sulfate bone scaffolds with controllable porous structure by selective laser sintering

“…The results showed that after various laser sintering power of 5, 6 and 7 W, all diffraction peaks of CaSO 4 did not change obviously and there aren't other diffraction peaks of phase to be detected, which suggested that no new phase occurred in the sintering process when laser power did not exceed 7 W. The patterns were consistent with one in previous study about CaSO 4 …”

“…Among these biological materials, CaSO 4 possesses good biocompatibility, bioresorbility and capability for bone repair [3,4]. When CaSO 4 is implanted in vivo, it can degrade and offer the main mineral constituent of bone tissue.…”

Mechanical properties and in vitro bioactivity of injectable and self-setting calcium sulfate/nano-HA/collagen bone graft substitute

“…Herein, calcium sulfate hemihydrate (CSH) was introduced into nHAC to form nHAC/CSH composites and to develop an injectable bone graft substitute. Besides good injectability and selfsetting property, the injectable bone graft substitute has good biocompatibility and strong ability to accelerate bone formation (Chen et al, 2011).…”

Setting Time Comparison of Four Antimicrobial Laden Calcium Sulfate Plasters

“…[7][8][9][10][11][12][13] Calcium sulfate hemihydrate (also called Plaster of Paris while unset, and gypsum when set) is commercially available as Osteoset (Wright Medical Technology, Inc, Arlington, TN, USA) and is historically known as a bone void filler with favorable scaffolding properties, safety, and in vivo resorption. 7,[14][15][16] Calcium sulfate is mainly used by the orthopaedic surgeon as antibiotic impregnated beads, where the rapid absorption rate of calcium sulfate may circumvent the need for removal that is seen when implanting other nonbioactive cements, such as polymethyl-methacrylate (PMMA). 17 The literature lacks a single resource for surgeons to reference when attempting to mix their own antimicrobial laden calcium sulfate.…”