Modification of PMMA Cements for Cranioplasty with Bioactive Glass and Copper Doped Tricalcium Phosphate Particles

Abstract

Cranioplasty represents the surgical repair of bone defects or deformities in the cranium arising from traumatic skull bone fracture, cranial bone deformities, bone cancer, and infections. The actual gold standard in surgery procedures for cranioplasty involves the use of biocompatible materials, and repair or regeneration of large cranial defects is particularly challenging from both a functional and aesthetic point of view. PMMA-based bone cement are the most widely biomaterials adopted in the field, with at least four different surgical approaches. Modifications for improving biological and mechanical functions of PMMA-based bone cement have been suggested. To this aim, the inclusion of antibiotics to prevent infection has been shown to provide a reduction of mechanical properties in bending. Therefore, the development of novel antibacterial active agents to overcome issues related to mechanical properties and bacterial resistance to antibiotics is still encouraged. In this context, mechanical, biological, and antibacterial feature against P. aeruginosa and S. aureus bacterial strains of surgical PMMA cement modified with BG and recently developed Cu-TCP bioactive particles have been highlighted.

Accuracy Assessment of Molded, Patient-Specific Polymethylmethacrylate Craniofacial Implants Compared to Their 3D Printed Originals

“…The most striking advantages of this process are the reduction of operation time [18,36], the use of common materials widely available, and the possibility to reuse the silicon mold in case of a revision operation. With the increase of the use of biocompatible materials [37] and bioprinting, these indirect processes, such as the molding of objects, will eventually become redundant in the future. Most likely, PSIs will be routinely 3D printed directly from PMMA bone cement, any other biocompatible material that is certified for implantation, or even of new autologous bone built from patients' cells.…”

Poly(lactic-co-glycolic acid)-based composite bone-substitute materials

“…However, the therapeutic efficacy is poor owing to its low mechanical strength and readily to be degraded by collagenase. Polymer-based artificial bone substitutes showing great potential in bone repair [ [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [56] , [57] ]. In comparison with previous materials, synthetic polymers have a range of advantages, such as controllable molecular mass and degradation time, excellent processability, and good mechanical properties.…”

Design of 3D Additively Manufactured Hybrid Structures for Cranioplasty

“…Copper-doped tricalcium phosphate (Cu-TCP) particles were employed to modify a PMMA-based cement (Palacos, Heraeus, Wehrheim, Germany). Specifically, the precipitation technique was used to obtain Cu 2+ -substituted TCP as previously described [ 17 ]. In brief, 0.5 mol/L solution of Cu(NO 3 ) 2 was mixed with 0.5 mol/L solution of Ca(NO 3 ) 2 , and 0.5 mol/L (NH 4 ) 2 HPO 4 solution was added.…”

“…The precipitate was then dried at 80 °C and calcined at 900 °C forming the whitlockite structure. PMMA cement was modified according to a previously reported procedure [ 17 ]. Cu-TCP particles were dispersed in the solid PMMA phase using ultrasonic dispersion.…”

“…The incorporation of silver [ 15 ] and gold [ 16 ] nanoparticles into PMMA bone cements has been suggested for antimicrobial and mechanical purposes. Recently, novel antibacterial agents, such as bioactive glass (BG) and copper doped tricalcium phosphate (Cu-TCP) particles, have been incorporated into surgical PMMA in order to prevent cranioplasty graft infections [ 17 ]. A low amount of Cu-TCP (i.e., 2.5 wt%) showed an efficient antibacterial effect while providing a mechanical reinforcement for the polymer matrix [ 17 ].…”