Blending polysaccharides with biodegradable polymers. II. Structure and biological response of chitosan/polycaprolactone blends

Abstract

Blends of polycaprolactone (PCL) and chitosan (CHT) were prepared by casting from the mixture of solutions of both components in suitable solvents. PCL, and CHT, form phase separated blends with improved mechanical properties and increased water sorption ability with respect to pure PCL. The morphology of the system was investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal microscopy. Dispersed domains of CHT in the semicrystalline PCL matrix were found in samples with less than 20% CHT but cocontinuous phase morphologies are found in blends with 20% or more CHT. This feature was corroborated by the temperature dependence of the elastic modulus measured by dynamic mechanical properties as a function of temperature. It was observed that for those blends above 20 wt% CHT, the mechanical stability of the system was kept even after melting of the PCL phase. Primary human chondrocytes were cultured on the different substrates. Cell morphology was studied by SEM and the viability and proliferation was investigated by the colorimetric MTT assay. Different protein conformations were found by AFM on CHT and PCL samples which were related to the biological performance of the substrates. Hydrophilicty of the material is not directly related to the biological response and the sample with 20 wt% CHT shows better results than the other blends with respect to chondrocyte viability and proliferation. However, the results obtained in the blends are worse than in pure PCL. It seems to be correlated with the surface energy of the different blends rather than hydrophilicity.

Differentiation of mesenchymal stem cells in chitosan scaffolds with double micro and macroporosity

“…Self‐fluorescence of CHT36 allows observing the micro and macropore structure of the scaffold that is especially clear in Figures 9(a) (in blue) and 10(b) (in violet due to the superimposition of both fluorescences: blue DAPI and red alexa‐647). These images confirm the isotropic contraction of the scaffold during porogen extraction and pore connectivity as previously accounted for by SEM and μ‐CT.…”

Three‐dimensional plotted alginate fibers embedded with diclofenac and bone cells coated with chitosan for bone regeneration during inflammation

“…These scaffolds fluoresced green under a fluorescent microscope with the light source set at 488 nm, indicating that chitosan was successfully coated on the alginate fibers [Fig. (a)].…”

Characterisation of a novel light activated adhesive scaffold: Potential for device attachment

“…Interestingly the RBC-scaffolds were significantly stained blue after the test (Figure 3c), whereas the controls did not stain significantly (Figure 3b). The quicker uptake of solution and staining could be attributed to the hydrophilic chitosan in the RBC coating absorbing the solution (García Cruz et al, 2008).…”