Biocompatibility and other properties of acrylic bone cements prepared with antiseptic activators

Abstract

Acrylic bone cements prepared with activators of reduced toxicity have been formulated with the aim of improving the biocompatibility of the final material. The activators used were N,N-dimethylaminobenzyl alcohol (DMOH) and 4,4'-dimethylamino benzydrol (BZN). The toxicity, cytotoxicity, and antiseptic action of these activators were first studied. DMOH and BZN presented LD50 values 3-4 times higher than DMT, were less cytotoxic against polymorphonuclear leucocytes, and possessed an antimicrobial character, with a high activity against the most representative microorganisms involved in postoperative infections. The properties of the acrylic bone cements formulated with DMOH and BZN were evaluated to determine the influence of these activators on the curing process and the physicochemical characteristics of the cements. A decrease of the peak temperature was observed for the curing with DMOH or BZN with respect to that of one commercially available formulation (CMW 3). However, residual monomer content and mechanical properties in tension and compression were comparable to those of CMW 3. The biocompatibility of acrylic bone cements containing DMOH or BZN was studied and compared with CMW 3. To that end, intramuscular and intraosseous implantation procedures were carried out and the results were obtained from the histological analysis of the surrounding tissues at different periods of time. Implantation of rods of cement into the dorsal muscle of rats showed the presence of a membrane of connective tissue, which increased in collagen fibers with time of implantation, for all formulations. The intraosseous implantation of the cements in the dough state in the femur of rabbits, revealed a higher and early osseous neoformation, with the presence of osteoid material surrounding the rest of the cured material, for the cement prepared with the activator BZN in comparison with that obtained following the implantation of the cement cured with DMOH or DMT (CMW 3).

Modification of acrylic bone cements by poly(ethylene glycol) with different molecular weight

“…[7] The liquid phase is usually added to the powder phase in a typical liquid to powder (L/P) ratio of 1:2. [8,9] The solid phase includes prepolymerized poly(methyl methacrylate) (PMMA) microspheres or related copolymers (~89 wt%), an initiator of the polymerization reaction-benzoyl peroxide (BPO) (~1 wt%) and BaSO 4 or ZrO 2 as a radiopacifiers (~10 wt%). [10,11] The liquid phase consists of methyl methacrylate monomer (MMA) (~97 vol.…”

Acrylic injectable and self‐curing formulations for the local release of bisphosphonates in bone tissue

“…The solid phase consisted of 87 wt % PMMA beads, 10 wt % ZrO 2 , 1.5 wt % of the corresponding BP and 1.5 wt % of benzoyl peroxide as a radical initiator. The liquid phase consisted of 69 wt % MMA, 20 wt % MVE, 10 wt % TEGDMA, and 1 wt % 4,4‐bis‐dimethylamino benzydrol as a low toxicity activator 17. The solid/liquid ratio was 1.8:1.…”

Alternative acrylic bone cement formulations for cemented arthroplasties: Present status, key issues, and future prospects

“…The second comprises polymerizable tertiary amines; that is, ones that possess an unsaturated group that permits the accelerator to be incorporated into the PMMA matrix chain. Examples are 4‐dimethylamino benzyl methacrylate,53 4‐dimethylamino benzyl alcholol,54 and 4,4‐dimethylamino benzydrol 55. The third grouping comprises tertiary amines based on long‐chain naturally‐occurring fatty acids, with examples being 4‐ N,N ‐dimethylamino‐4‐benzyl laurate (DMAL) and 4‐ N,N ‐dimethylamino‐4‐benzyl oleate (DMAO) (which is derived from oleic acid).…”