The biocompatibility of porous vs non-porous bone cements: a new methodological approach

Abstract

Composite cements have been shown to be biocompatible, bioactive, with good mechanical properties and capability to bind to the bone. Despite these interesting characteristic, in vivo studies on animal models are still incomplete and ultrastructural data are lacking. The acquisition of new ultrastructural data is hampered by uncertainties in the methods of preparation of histological samples due to the use of resins that melt methacrylate present in bone cement composition. A new porous acrylic cement composed of polymethyl-metacrylate (PMMA) and β-tricalcium-phosphate (p-TCP) was developed and tested on an animal model. The cement was implanted in femurs of 8 New Zealand White rabbits, which were observed for 8 weeks before their sacrifice. Histological samples were prepared with an infiltration process of LR white resin and then the specimens were studied by X-rays, histology and scanning electron microscopy (SEM). As a control, an acrylic standard cement, commonly used in clinical procedures, was chosen. Radiographic ultrastructural and histological exams have allowed finding an excellent biocompatibility of the new porous cement. The high degree of osteointegration was demonstrated by growth of neo-created bone tissue inside the cement sample. Local or systemic toxicity signs were not detected. The present work shows that the proposed procedure for the evaluation of biocompatibility, based on the use of LR white resin allows to make a thorough and objective assessment of the biocompatibility of porous and non-porous bone cements.

Simple method for increasing drug elution from polymethylmethacrylate bone cement

“…It was also reported that the increased porosity in PMMA cement helps in vivo biocompatibility. [16,17] Carbon dioxide trapped inside the cement block will be released gradually as the liquid occupies more space inside the pores. We estimate that the amount of gas would be negligible enough for compensation if the effervescent reaction exhausts outside the body.…”

Injectable and biodegradable composite bone filler composed of poly(propylene fumarate) and calcium phosphate ceramic for vertebral augmentation procedure: An in vivo porcine study

“…Although calcium phosphate cement (CPC) and calcium sulfate show improved thermal characteristics, bone induction abilities, bioresorbability, and biocompatibility, the relatively long setting time and insufficient initial mechanical strength result in subsequent problems, such as poor handling, fixation collapse, and early resorption . Other research groups have developed composite bone cements such as hydroxyapatite acrylic monomer, hydroxyapatite composite resin, and carbon fiber‐reinforced polyether ether ketone composite . These alternatives have similar properties to PMMA with the additional benefits of including appropriate viscosity, nontransmission of X‐rays, controllable setting time, low setting temperature, and better mechanical properties, among others .…”

“…[17][18][19][20] Other research groups have developed composite bone cements such as hydroxyapatite acrylic monomer, hydroxyapatite composite resin, and carbon fiber-reinforced polyether ether ketone composite. 21,22 These alternatives have similar properties to PMMA with the additional benefits of including appropriate viscosity, nontransmission of X-rays, controllable setting time, low setting temperature, and better mechanical properties, among others. 16,22 While others have reported success using a degradable and nontoxic polymer, poly(propylene fumarate) (PPF) with or without calcium phosphate cement, concerns remain regarding its rapid degradation, potentially inflammatory degradation products, radiolucency, and poor osteoconductivity.…”

Assessment of the injection behavior of commercially available bone BSMs for Subchondroplasty® procedures

“…They are designed to be osteoconductive and resorbable [8]. For example, CaPs can be partially resorbed by osteoclastic elements, releasing in the process calcium and phosphate ions, which are promoters of bone apposition [9]. This quality makes calcium phosphate an osteoconductive The Knee xxx (2015) xxx-xxx ceramic by nature with a good biocompatibility specific for bone [10].…”