To promote osteointegration, bioactive cuttlebone particles containing collagen were used to fill an acrylic cement, varying filler concentration (0-50 wt%). Cuttlebone was characterized by X-ray diffraction, plasma atomic emission and FT-IR. Mechanical properties of the filled cement were determined following ASTM procedures, included stress-strain, compression, bending, and fracture toughness tests. For in vivo tests, three groups of seven adult healthy rabbits were prepared to make an implant in the parietal bone of each one. For such groups (I-III), the amount of filler in the cement was 0, 10 and 30 wt%, respectively. Mechanical results for the composites complied with norm requirements. However, as mechanical performance for composite with 50 wt% of filler decreased significantly, for the in vivo tests, such composite was excluded. In vivo tests showed that three implants of group I were loosely attached to the parietal bone, whereas all the implants made with cement containing cuttlebone particles (groups II and III) were firmly attached to the parietal bone, indicating osteointegration. These results clearly show the potential of this type of bioactive filler to be used for medical applications.

Summary: Bioactive cuttlebone Sepia officinalis particles that contain collagen were used to fill poly (methyl methacrylate-co-styrene) bone cements, varying size and concentration of filler particles. Cuttlebone was characterized by X-ray diffraction and plasma atomic emission spectrophotometer. Maximum reaction temperature and cement setting time were determined for composites and reference (copolymer without filler), along with NMR determination of residual monomer concentration. Mechanical properties characterization included stress-strain, bending, compression, fracture toughness and storage modulus tests. Mechanical results for composites filled with 10 and 30% weight of cuttlebone, complied with norm requirements which opens the possibility for using cuttlebone particles as bioactive filler.

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Two-stage polymerization has been used to improve properties of two-component polymers. In this work, a semicontinuous emulsion process varying feed composition along the reaction is used to produce copolymer chains of different composition as conversion proceeds. Polymer composition and evidence of branching were determined by 1 H-NMR. Polymer molecular weight values determined by GPC are beyond the range where mechanical properties depend on molecular weight. Mechanodynamic properties show a copolymer type behavior with a synergistic effect around the 50/50 styrene/butyl acrylate composition ratio. For such composition, mechanical performance superiority of variable composition copolymer with respect to two-stage polymer was confirmed with stress-strain tests carried out at several temperatures.