Development of porous hydroxyapatite/PVA/gelatin/alginate hybrid flexible scaffolds with improved mechanical properties for bone tissue engineering

• Published in: Materials chemistry and physics 2024-06, Vol.319, p.129332, Article 129332
• Main Authors: El-Bahrawy, Nadia R, Elgharbawy, Hani, Elmekawy, Ahmed, Salem, Mohamed, Morsy, Reda
• Format: Article
• Language: English
• Subjects: Bone tissue engineering; Freeze-drying; Hydroxyapatite-gelatin; Porous hybrid scaffolds; PVA-Alginate
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2024.129332

Porous scaffolds based on gelatin and hydroxyapatite particles (HAp) are promising for applications in bone tissue engineering and regenerative medicine. However, they are not ideal for stress and shock protection due to low compressive strength, brittleness, and poor toughness. Herein, we developed porous hybrid scaffolds by combining multiple components into a single bone scaffold, including hydroxyapatite nanoparticles (HAp NPs), alginate, polyvinyl alcohol (PVA), and gelatin with different gelatin/PVA composition ratios. HAp NPs were synthesized in situ in PVA solution and scaffolds were fabricated using a freeze-drying method. The results showed good physicochemical properties of the scaffolds: formation of pure HAp NPs phase, high porosity, large pore sizes, large swelling capacity depending on varying gelatin/PVA ratios, as well as a long-term degradation rate up to 28 days. The porous scaffolds exhibited compressive strength close to the cancellous bone with stress-strain behavior exhibiting three-stage flexible behavior indicating improved fracture resistance with an energy absorbing capability up to 1.9 MJ/m3. The scaffolds have a yield strength of 70–403 kPa, a compressive strength at 65 % strain of 0.96–1.80 MPa, a nonporous elastic modulus of 10.44–12.40 GPa, and a densification strain of approximately 0.92 %. This work develops three-dimensional (3D) porous hybrid bone scaffolds with mechanical strength within the minimum compressive strength of cancellous bone and mechanical energy absorption capacity favor for cancellous bone repair, bone tissue engineering, and regenerative medicine applications. [Display omitted] •Novel porous hybrid scaffolds were prepared by incorporating multiple components into a single bone scaffold.•Scaffolds were prepared by freeze-drying of HAp, alginate, PVA, and gelatin with different gelatin/PVA composition ratios.•Stress-strain behavior of the scaffolds showed a three-stage flexible behavior mimicking cancellous bone.•Scaffolds have compressive strength and mechanical energy absorption capacity suitable for bone tissue engineering.•The scaffolds present good physicochemical properties, porosity, swelling ratio, and degradation rate.