Bone tissue engineering is gaining popularity as an alternative method for the treatment of osseous defects. A number of biodegradable polymers have been explored for tissue engineering purposes. A new family of biodegradable polymer/bioactive glass composite materials has been designed to be used in bone regeneration approaches. In this work, a hybrid scaffold of chitosan (CH) and bioactive glass nanoparticles (BGN) was prepared by the freeze‐gelation method. This method has been studied by adjusting the concentration of acetic acid; this process can influence the structure properties of the scaffold. In this work, several BGN/CH composites have been prepared by varying the proportion of BGN in the hybrid scaffold (20, 40, 60, and 80%). Brunauer–Emmett–Teller results showed the increased surface area and porosity volume of our composite with decreasing BGN proportion. BGN/CH hybrid scaffold was characterized by using physicochemical techniques. Obtained results showed a macroporous morphology of the scaffold with a pore size of about 200 μm, and a homogeneous distribution of the BGN in the CH matrix. X‐ray diffraction study confirmed the amorphous state of the BGN/CH hybrid scaffold. Interaction between CH and BGNs in the composite was confirmed. The in vitro assays showed adequate degradation properties, which is essential for the potential replacement by the new tissue. The in vitro bioactivity studies confirmed the formation of an apatite layer on the surface of the hybrid scaffold, which results in a direct bone bonding of the implant. These results indicate that BGN/CH hybrid scaffold developed is a potential candidate for bone tissue engineering.

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Bioactive glasses have the physical characteristics enabling them to be used in bone tissue engineering applications. However, the exact mechanism of the interactions between the glass surface and environment leading to the transition from the vitreous phase to the crystalline phase remains a subject of study. This work focuses on the growth of a calcium phosphate layer on the surface of the glass after immersion in a mineral solution, which mimics the mineral phase of human blood. The investigations use the Inductively Coupled Plasma and the Atomic Force Microscopy to establish the kinetic of crystallization, the kinetic of chemical reactivity and the surface transformations such as structure, texture and morphology of the bioactive glass. Obtained results show the progressive formation of a hydroxyapatite layer within 2 weeks. This crystal which is that of the bone belongs to the crystallographic structure within space group of P6 3/m. In addition, results show a decrease of the gradient of thickness which varies according to the immersion time from 7.5 µm to 2.8 µm and an increase of the homogeneity of the surface visible by the lowering of the gradient in the phase measurement from 60 Å to 15 Å.

This research is based on the study of bioactivity kinetic in function of the glass particles size. Bioactive glasses have been elaborated in the ternary system SiO2-CaO-P2O5. Nano bioactive glass and micro bioactive glass have been synthesized by using two different processes. They are destined for use as bone biomaterials. The comparison was focused on the kinetic of the development of a calcium phosphate layer on their surfaces after immersion in a Simulated Body Fluid (SBF). The first bioactive glass BG is a melting-made glass with a particles size of about 60 μm. The second bioactive glass NBG is a sol-gel made glass through an emulsion system of synthesized particles of about 110 nm. The growing of the calcium phosphate layer at the surface of the glasses has been followed using several physicochemical techniques. Obtained results show the development of a calcium phosphate layer similar to carbonated hydroxyapatite. It crystallises in a hexagonal system with an P63/m space group. While melting-made glass needs 14 days to develop carbonated hydroxyapatite like crystal, sol-gel needs only 3 days to develop similar crystals. This difference offers wide opportunities and complementarities for the use of nano or micro bioactive glasses in the biomedical field.

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