• Fabrication and Characterization of PMMA-Based Bone Cement Enriched with Chitosan and Allograft Bone Powder
  • Sara Tabatabaee,1 Mahsa Delyanee,2 Reza Samanipour,3 Amirhossein Tavakoli,4,*
    1. Research and Development Specialist, Iranian Tissue Product Company, Tehran, Iran
    2. Biomedical Engineering Department, Amirkabir University of Technology, Tehran, Iran
    3. Research and Development Supervisor, Iranian Tissue Product Company, Tehran, Iran
    4. Iranian Tissue Bank and Research Center, Tehran University of Medical Sciences, Tehran, Iran


  • Introduction: Polymethyl methacrylate (PMMA) and its derivatives have been proficiently utilized in orthopedic surgeries aimed for filling the undesired cavities in similar forms of the surrounding tissue and eventually, stablishing a strong integration with the native tissue. However, the insufficient mechanical compatibility as well as the lack of bioactivity of PMMA bone cements has led to several investigations in case of the enhancement of their structural and biological characteristics. It has been reported in previous literature that loading chitosan in PMMA resulted in reducing the polymerization temperature and improving bone regeneration capability of the compound. Moreover, regarding the reported biocompatibility of allograft bone substitutes such as bone powders, the biological performance of the cement could be promoted via using this human-derived material and the mineral phase of bone would be mimicked optimally. Therefore, in the following project, a developed bone cement composed of PMMA, chitosan and allograft bone powder was fabricated and characterized.
  • Methods: Allograft bone powder was processed chemically and mechanically after donor screening and assuring of lack of any bioburden (bacteria, viruses, molds, etc.) in Iranian Tissue Product Company (ITP). A solution consists of bone powder and chitosan in acetic acid 2% was produced. A homogenous powder was prepared by freeze-drying the solution and ball-milling the resulted bulks. The powder was then added to the PMMA powder (30% w/w). The liquid phase of the cement (methyl methacrylate monomer) was poured on the final powder in a 1:2 ratio. Benzoyl peroxide and N,N-Dimethyl-p-toluidine were also used as initiator and catalyzer of the polymerization process. The microstructure of the cement was observed by scanning electron microscopy (SEM). Furthermore, the bioactivity of the sample was evaluated through immersing in simulated body fluid (SBF) and examining the created crystals on the surface after 21 days. The biocompatibility was investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and culturing human mesenchymal stem cells (hMSCs) on bone cements after 72h.
  • Results: According to the SEM images, a well-defined arrangement of PMMA and the chitosan-bone powder was observed as evidence of the efficient polymerization of PMMA and no unsuitable intervention of chitosan – bone powder in the process. After 21 days of soaking the cement in SBF solution, its surface was covered with apatite-like formations. On this basis, the bioactivity of the cement due to its mineral compound similar to the native bone tissue was approved. Also, its biocompatibility was demonstrated via a 98% cellular viability reported by MTT assay after 72h.
  • Conclusion: Considering the well-arranged structural characteristics, the optimum bioactivity, and the improved biocompatibility of the prepared bone cement, it could be revealed that the PMMA-Chitosan-Allograft Bone Powder bone cement is a promising candidate for successfully employing in orthopedic surgeries.
  • Keywords: Bone Cement, PMMA, Allograft Bone, Chitosan, Tissue Engineering.