Acrylic bone cements modified with poly(ethylene glycol)‐based biocompatible phase‐change materials

Abstract

The high polymerization temperature of acrylic bone cements used in hip replacement implantation may cause thermal necrosis of surrounding tissues. In order to reduce the polymerization temperature, acrylic bone cement has been modified with a biocompatible polymeric phase‐change material (PCM) based on poly(ethylene glycol) (PEG) of different molecular weights and stabilized with potato starch. Structural and morphological studies were performed, and the thermal and mechanical properties were investigated. The incorporation of PEG‐based PCM led to a decrease in the polymerization temperature of bone cement from 70 °C for unmodified cement to 58 °C for modified cement. Modified cement materials were stable in incubation tests, although acoustic analysis data revealed a decrease in propagation speed after incubation, which indicates formation of material defects (pores, cracks, voids, etc.) due to water activity. However, in the regeneration process, these defects can be filled by freshly grown bone tissue leading to better incorporation of bone cement replacements into tissue. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43898.

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

“…Several different solutions have been proposed so far to reduce maximum curing temperature of PMMA bone cements. Among them, phase change materials (PCMs) can be used as bone cements modifiers . PCMs are capable of storing a large amount of latent heat from surrounding ambient during the melting phase transition .…”

A review of calcium phosphate cements and acrylic bone cements as injectable materials for bone repair and implant fixation

“…For example, adding chitosan or starch-stabilized polyethylene glycol to PMMA bone cement has been shown to reduce the maximum curing temperature of the cement. 56,166 Although chitosan did not appear to affect the tensile properties, it increased the compressive strength of the chitosan/PMMA cement. 166 Chitosan is expected to degrade over time in vivo as the new bone tissue forms, which could enable the generation of a porous network over time for bone ingrowth.…”

“…55 In general, PMMA bone cement has a relatively high mechanical strength and offers a suitable curing time and ease of application. 56 The ISO standard 5833 for bone cements requires a compressive strength of ⩾ 70 MPa. 57 There is a growing body of literature on the development of new bone graft substitutes, making use of synthetic inorganic/organic compounds as well as composites of demineralized bone with various self-setting pastes.…”

“…166 This is considered a drawback, as the high temperature during curing may reach up to 110°C. 56,164 High temperatures can lead to thermal necrosis of the bone cells and extensive bone damage, 164,167 since collagen denatures with prolonged exposure to temperatures in excess of 56°C. 168,169 In addition, PMMA bone cement is not absorbable, with no functions of bone conduction or induction.…”

“…55 In general, PMMA bone cement has a relatively high mechanical strength and offers a suitable curing time and ease of application. 56 The ISO standard 5833 for bone cements requires a compressive strength of ⩾ 70 MPa. 57…”