[Experimental study on biocompatibility of vascular tissue engineering scaffold of epsilon-caprolactone and...

To explore the method of preparing the electrospinning of synthesized triblock copolymers of epsilon-caprolactone and L-lactide (PCLA) for the biodegradable vascular tissue engineering scaffold and to investigate its biocompatibility in vitro.

The biodegradable vascular tissue engineering scaffold was made by the electrospinning process of PCLA. A series of biocompatibility tests were performed. Cytotoxicity test: the L929 cells were cultured in 96-well flat-bottomed plates with extraction media of PCLA in the experimental group and with the complete DMEM in control group, and MTT method was used to detect absorbance (A) value (570 nm) every day after culture. Acute general toxicity test: the extraction media and saline were injected into the mice's abdominal cavity of experimental and control groups, respectively, and the toxicity effects on the mice were observed within 72 hours. Hemolysis test: anticoagulated blood of rabbit was added into the extracting solution, saline, and distilled water in 3 groups, and MTT method was used to detect A value in 3 groups. Cell attachment test: the L929 cells were seeded on the PCLA material and scanning electron microscope (SEM) observation was performed 4 hours and 3 days after culture. Subcutaneous implantation test: the PCLA material was implanted subcutaneously in rats and the histology observation was performed at 1 and 8 weeks.

Scaffolds had the characteristics of white color, uniform texture, good elasticity, and tenacity. The SEM showed that the PCLA ultrafine fibers had a smooth surface and proper porosity; the fiber diameter was 1-5 microm and the pore diameter was in the range of 10-30 microm. MTT detection suggested that there was no significant difference in A value among 3 groups every day after culturing (P > 0.05). The mice in 2 groups were in good physical condition and had no respiratory depression, paralysis, convulsion, and death. The hemolysis rate was 1.18% and was lower than the normal level (5%). The SEM showed a large number of attached L929 cells were visible on the surface of the PCLA material at 4 hours after implantation and the cells grew well after 3 days. The PCLA material was infiltrated by the inflammatory cells after 1 week. The inflammatory cells reduced significantly and the fiber began abruption after 8 weeks.

The biodegradable vascular tissue engineering scaffold material made by the electrospinning process of PCLA has good microstructure without cytotoxicity and has good biocompatibility. It can be used as an ideal scaffold for vascular tissue engineering.