Designing Porous Bone Tissue Engineering Scaffolds with Enhanced Mechanical Properties from Composite Hydrogels Composed of Modified Alginate, Gelatin, and Bioactive Glass

Abstract

The combination of biodegradable polymers and bioactive inorganic materials is being widely used for designing bone tissue engineering scaffolds. Here we report a composite hydrogel system composed of bioactive glass incorporated in covalently cross-linked oxidized alginate-gelatin hydrogel (ADA-GEL) for designing porous scaffolds with tunable stiffness and degradability using freeze-drying technique. Because of the presence of bioactive glass, the cross-linking kinetic and cross-linking degree of the hydrogels are significantly increased, which is the main factor for the measured enhanced mechanical strength of the bioactive glass containing ADA-GEL scaffolds. The hydrogels with high crosslinking degree exhibit low protein release profile and low degradability. Apatite formation on bioactive glass containing hydrogelbased scaffolds is confirmed by FTIR. Bone marrow-derived stromal cell growth is promoted in pristine ADA-GEL and 1% bioactive glass containing ADA-GEL scaffolds compared to the scaffolds of pure alginate, alginate−gelatin blended hydrogel, and 5% bioactive glass containing ADA-GEL. Initial studies indicated that the scaffolds, especially without bioactive glass, support osteogenic differentiation of murine bone marrow stromal cell line in the absence of foreign osteogenic stimulating supplements; however, they exhibit low levels of osteogenic expression.

The Tunable Porous Structure of Gelatin–Bioglass Nanocomposite Scaffolds for Bone Tissue Engineering Applications: Physicochemical, Mechanical, and In Vitro Properties

“…Obtained results approved enhancement and improvement of compression strength after addition of BGNPs. The study of Sarker et al [51] was also indicated an improvement in compression strength after enhancement of BG content. The substantial influence of unidirectional pores in freeze casting scaffolds on the increased mechanical stability should not be ignored as focused in our previous study.…”

Synthesis and Characterization of Thermosensitive Poly(N‐Vinyl Caprolactam)‐Grafted‐Aminated Alginate Hydrogels

“…As a result of this, both the pore structure and pore size of the PNVCL‐ g ‐Alg‐NH 2 scaffold also decreased. Pore structure, size, and distribution of the hydrogel constructs are known to influence the equilibrium swelling ratio, the release profile, mobility, and mass transfer …”

“…Pore structure, size, and distribution of the hydrogel constructs are www.advancedsciencenews.com www.mcp-journal.de known to influence the equilibrium swelling ratio, the release profile, mobility, and mass transfer. [41] Quantitative analyses of Alg, Alg-NH 2 , and PNVCL-g-Alg-NH 2 are given in Figure 7. In the the figure, carbon (C), oxygen (O), and sodium (Na) elements are detected for Alg and their peaks were observed around 0.25, 0.5, and 1.1 keV respectively.…”

Preparation and properties of dopamine‐modified alginate/chitosan–hydroxyapatite scaffolds with gradient structure for bone tissue engineering

“…9,46 By implanting the Alg-DA/QCHA gradient scaffold in rabbit femoral defect in vivo, the area of the defect was significantly reduced and a lot of the new bone tissues grew in the Alg-DA/QCHA gradient scaffolds group at 12 weeks after surgery, compared with the blank group and homogenous scaffold. The obtained gradient scaffolds showed high compression modulus, which were contributed to the existing of HA component and the stronger hydrogen bond and electrostatic interactions among the DA groups and the Alg and QCS chains.…”