Bioactive glass/polymer composite scaffolds mimicking bone tissue

Abstract

The aim of this work was the preparation and characterization of scaffolds with mechanical and functional properties able to regenerate bone. Porous scaffolds made of chitosan/gelatin (POL) blends containing different amounts of a bioactive glass (CEL2), as inorganic material stimulating biomineralization, were fabricated by freeze-drying. Foams with different compositions (CEL2/POL 0/100; 40/60; 70/30 wt %/wt) were prepared. Samples were crosslinked using genipin (GP) to improve mechanical strength and thermal stability. The scaffolds were characterized in terms of their stability in water, chemical structure, morphology, bioactivity, and mechanical behavior. Moreover, MG63 osteoblast-like cells and periosteal-derived stem cells were used to assess their biocompatibility. CEL2/POL samples showed interconnected pores having an average diameter ranging from 179 ± 5 μm for CEL2/POL 0/100 to 136 ± 5 μm for CEL2/POL 70/30. GP-crosslinking and the increase of CEL2 amount stabilized the composites to water solution (shown by swelling tests). In addition, the SBF soaking experiment showed a good bioactivity of the scaffold with 30 and 70 wt % CEL2. The compressive modulus increased by increasing CEL2 amount up to 2.1 ± 0.1 MPa for CEL2/POL 70/30. Dynamical mechanical analysis has evidenced that composite scaffolds at low frequencies showed an increase of storage and loss modulus with increasing frequency; furthermore, a drop of E' and E″ at 1 Hz was observed, and for higher frequencies both moduli increased again. Cells displayed a good ability to interact with the different tested scaffolds which did not modify cell metabolic activity at the analyzed points. MTT test proved only a slight difference between the two cytotypes analyzed.

3D interconnected porous biomimetic scaffolds: In vitro cell response

“…However, the scaffolds at lower inorganic phase content, as well as GEL scaffolds, also exhibited good mechanical properties. 29,35 In vitro biological tests In vitro biological tests were carried out on GEL and on G-HA10 in order to investigate bone cells response to the 3D scaffolds, and to assess the influence of the presence of the inorganic phase on osteoblast proliferation and differentiation.…”

Bioactive Glass-Biopolymer Composites for Applications in Tissue Engineering

“…In this technique, a solution, dispersion, or emulsion consisting of a solvent, the polymer, and the inorganic nanoparticles (and in some cases a cross-linking agent such as glutaraldehyde, genipin, or other) is subjected to rapid gelation, which causes the solids or the solute to be displaced by an advancing ice front into the interstitial spaces between ice crystals [88][89][90]. Once fully frozen, the freeze-drying process itself takes place, which typically employs temperatures of À20 to À80 C for different periods of time.…”

Emulsion cross-linked chitosan/nanohydroxyapatite microspheres for controlled release of alendronate

“…This limitation could be minimized by combining inorganic material into the composite, such as bioactive glass [19], hydroxyapatite [20], silicon, titanium, and tricalcium phosphate (TCP) [21]. Among these, hydroxyapatite is the most favorable element for bone defect treatment and is the principal inorganic constituent of human bones.…”