Application of long chain amine activator in conventional acrylic bone cement

Abstract

A long chain acid derivative bearing an aromatic tertiary amine group, 4-N,N-dimethylaminobenzyl laurate (DML), which acts as an activator for the curing of acrylic cements at low temperature, has been synthesized and characterized to reduce the biological adverse effects usually associated with the classical activator N,N-dimethyl-4-toluidine (DMT). The effectiveness of the activator was tested on commercial formulations (e.g., Palacos R) and on experimental bone cements based on poly (methyl methacrylate) by using different benzoyl peroxide/amine molar ratios. The exotherms of polymerization were followed at three different temperatures: 25, 30, and 37 degrees C. The DML activator was found to be more sensitive to temperature than the corresponding DMT. DML provided exotherms of polymerization with decreasing peak temperatures and increasing setting times without impairing the mechanical properties. Residual monomer content was analyzed in a range of activator concentrations by keeping the benzoyl peroxide concentration constant. In all cases the residual monomer content was lower than 5%, indicating its good efficiency in the benzoyl peroxide initiated polymerization.

Thermal and dynamic mechanical characterization of acrylic bone cements modified with biodegradable polymers

“…Different approaches, using di-functionalized methacrylates such as 2,2-bis [4(2-hydroxy-3-methacryloxypropoxy) phenyl] propane (Bis-GMA), 8 ethylene, or triethylenglycol dimethacrylate, 9 have led to a decrease in the volumetric shrinkage as well as a significant improvement in mechanical properties. 10,11 From the point of view of the red-ox initiator system, the use of tertiary amines (such as 4 -N, N-dimethylaminobenzoyl laurate, 12 4,4-dimethylamino benzoyl alcohol, 13 or 4,4 0 -(dimethylamino)diphenyl carbinol (BZN) 14,15 ) has demonstrated to induce lower toxicity than the commonly used N, N-dimethylamino-4toluidine.…”

Water absorption characteristics and cytotoxic and biological evaluation of bone cements formulated with a novel activator

“…Rectangular shaped specimens (approximately 20 ϫ 10 mm) from Palacos, Palacos powder component with DML as activator (PalDML) and an experimental cement with PMMA beads from QL Industrias with DML were prepared, respectively, as described in an earlier article, 6 for water absorption and biochemical evaluation. The composition of the cement formulations are shown in Table I.…”

“…[4][5] Chemical damage from residual constituents, mainly the monomer and the activators, can also compromise the bone-cement interface. We have recently reported the use of an alternative novel activator N,N,Dimethylamino 4-benzyl laurate (DML), 6 synthesized from a long chain acid derivative, lauric acid in the curing of PMMA acrylic bone cements.…”

Evaluation of peroxide initiators for radical polymerization‐based self‐healing applications

“…Decreasing porosity is expected to increase cement resistance to crack propagation and other relevant mechanical properties, whereas decreasing viscosity improves ease of processing as well as the ability of the cement to penetrate into the cancellous bone, thereby increasing the shear strength of the bone‐cement interface 19. Research has also focused on the development of more reactive and less toxic polymerization initiation activators,26–31 alternative cement monomers,32–35 and the use of osteoconductive additives for improved cement biocompatibility and mechanical properties of the weak‐link zones by supporting the growth of bone cells on the cement construct 36–38. The recent development of self‐healing polymers presents an opportunity for research on extending the lifetime of bone cements.…”