Polycaprolactone-chitosan/multi-walled carbon nanotube: A highly strengthened electrospun nanocomposite scaffold for cartilage tissue engineering

Articular cartilage is an avascular connective tissue with a slow healing rate. Tissue engineering scaffolds can provide appropriate condition to stimulate the natural healing mechanism of the damaged tissue. In this study, the electrospun nanocomposite scaffolds based on polycaprolactone (PCL)-chitosan/carboxyl-functionalized multi-walled carbon nanotubes (MWCNTs) were fabricated with different concentrations of MWCNTs including 0.5 and 1 wt%. The samples were characterized in terms of morphology, porosity, physicochemical structure, hydrophilicity, tensile strength, bioactivity, biodegradation and cell response. The scaffold containing 0.5 wt% MWCNTs presented the lowest fiber diameter (99 +/- 15 nm) and the highest tensile strength (33.81 +/- 6.76 MPa) (p <= 0.05), which were considerable for electrospun structures. The porosity percentage of the scaffolds were maintained above 80% which is appropriate for tissue engineering. As the MWCNTs increased, the water contact angle decreased due to the increase in the hydrophilic carboxyl functional groups related to the MWCNTs. MWCNTs increased the crystallinity of the scaffold, leading to a more bioactivity and stability proportional to healing rate of a natural cartilage. Chondrocytes were well cultured on the scaffold containing MWCNTs and presented more cell viability compared to the sample without MWCNTs. The PCL-chitosan/0.5wt.%MWCNTs scaffold can be considered for supplemental studies in cartilage tissue engineering applications.

Automated summary

This study fabricated electrospun nanocomposite scaffolds based on polycaprolactone (PCL)-chitosan/carboxyl-functionalized multi-walled carbon nanotubes (MWCNTs) with different concentrations of MWCNTs. The scaffolds were characterized and it was found that the scaffold containing 0.5 wt% MWCNTs had the smallest fiber diameter and highest tensile strength, with a porosity suitable for tissue engineering. Increasing the MWCNTs content decreased the water contact angle and increased the scaffold's crystallinity, leading to enhanced bioactivity and stability for cartilage healing. Chondrocytes cultured on the scaffold with MWCNTs showed good viability.