Bone regeneration response in an experimental long bone defect orthotopically implanted with alginate-pullulan-glass-ceramic composite scaffolds.

In the present study, scaffolds based on alginate-pullulan-bioactive glass-ceramic with 0.5 and 1.5 mol % copper oxide were orthotopically implanted in experimental rat models to assess their ability to heal an induced bone defect. By implying magnetic resonance and imaging scans together with histological evaluation of the processed samples, a progressive healing of bone was observed within 5 weeks. Furthermore, as the regenerative process continued, new bone tissue was formed, enhancing the growth of irregular bone spicules around the scaffolds. A significantly higher amount of new bone was formed (37%) in the defect that received the composite with 1.5 mol % CuO (in glass-ceramic matrix) content implant. Nevertheless, the bone regeneration obtained by scaffold with 0.5 mol % CuO implanted is comparable with the alginate-pullulan-ß-tricalcium phosphate/hydroxiapatite composite implant. The assessed amount of new bone formed was found to be between 29.75 and 37.15% for all the composition involved in the present study. During this process a regeneration process was shown when the alginate-pullulan composite materials were involved, fact that indicate the great potential of these materials to be used in tissue engineering.

New alginate-pullulan-bioactive glass composites with copper oxide for bone tissue regeneration trials.

Composites based on sodium alginate, pullulan, and bioactive SiO2 -CaO-P2 O5 glass-ceramics with copper oxide were prepared as capsules. The obtained samples were structurally characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM), and their bioactivity and biocompatibility properties were also tested both in vitro and in vivo by XRD, FT-IR, SEM, and high-resolution transmission electron microscopy. The fibroblast and osteoblast cell viability assays have shown good proliferation rates for all investigated samples, whereas all composites exhibited a good in vivo tolerance. The recovered composites after 5 weeks' in vivo and in vitro trials evidenced clear macroscopic alterations; particularly, after soaking in simulated body fluid, they have a corn flake aspect, and after their in vivo inoculation, a globular shape is retained. Different crystalline shapes of hydroxyapatite were formed after in vitro and in vivo trials for the glass-ceramic-polymer composites, the in vitro precipitated apatite was found to be nodular, and the in vivo experiment led to needlelike crystallites formation. Histopathological results showed a good biocompatibility with no significant signs of rejection by the host tissue. These assessments performed on the composites indicate that the studied materials can be considered without any doubt suitable candidates for future bone regeneration applications.