Fabrication and characterization of hydrothermal cross-linked chitosan porous scaffolds for cartilage tissue engineering applications

Abstract

The use of various chemical cross-linking agents for the improvement of scaffolds physical and mechanical properties is a common practical method, which is limited by cytotoxicity effects. Due to exerting contract type forces, chondrocytes are known to implement shrinkage on the tissue engineered constructs, which can be avoided by the scaffold cross-linking. In the this research, chitosan scaffolds are cross-linked with hydrothermal treatment with autoclave sterilization time of 0, 10, 20 and 30min, to avoid the application of the traditional chemical toxic materials. The optimization studies with gel content and crosslink density measurements indicate that for 20min sterilization time, the gel content approaches to ~80%. The scaffolds are fully characterized by the conventional techniques such as SEM, porosity and permeability, XRD, compression, thermal analysis and dynamic mechanical thermal analysis (DMTA). FT-IR studies shows that autoclave inter-chain cross-linking reduces the amine group absorption at 1560cm and increase the absorption of N-acetylated groups at 1629cm. It is anticipated, that this observation evidenced by chitosan scaffold browning upon autoclave cross-linking is an indication of the familiar maillard reaction between amine moieties and carbonyl groups. The biodegradation rate analysis shows that chitosan scaffolds with lower concentrations, possess suitable degradation rate for cartilage tissue engineering applications. In addition, cytotoxicity analysis shows that fabricated scaffolds are biocompatible. The human articular chondrocytes seeding into 3D cross-linked scaffolds shows a higher viability and proliferation in comparison with the uncross-linked samples and 2D controls. Investigation of cell morphology on the scaffolds by SEM, shows a more spherical morphology of chondrocytes on the cross-linked scaffolds for 21days of in vitro culture.

The Impact of the Ionic Cross-Linking Mode on the Physical and In Vitro Dexamethasone Release Properties of Chitosan/Hydroxyapatite Beads

“…The assignments and corresponding band position for CS, TPP, HA, and DEX are described in Table 2 and are in agreement with the literature [10,42,43,[50][51][52][53][54]. The spectra of chitosan beads prepared at pH = 6.0 (CS-TPP6, CS/HA-TPP6, CS/DEX-TPP6, and CS/HA/DEX-TPP6) also exhibited a new band at 1210 cm −1 (Figure 4a), consistent with the literature [46][47][48].…”

“…The assignments and corresponding band position for CS, TPP, HA, and DEX are described in Table 2 and are in agreement with the literature [10,42,43,[50][51][52][53][54].…”

Development of gelatin/chitosan/PVA hydrogels: Thermal stability, water state, viscoelasticity, and cytotoxicity assays

“…The polysaccharides and proteins are highly hygroscopic and have a strong affinity toward water molecules, 24 and depend on their macromolecular structure, for example, amorphous or crystalline state of the samples. The first stage occurred from 50 to 200 C and was associated with the loss of moisture.…”

Construction of tissue-engineered cartilage with different biological scaffolds in vitro

“…[1][2][3] An important aspect of tissue engineering is the design of polymeric scaffolds that have good mechanical and biological properties. 4…”