Poly(lactide-co-glycolic acid) (PLGA) is biodegradable polymer, which is approved by FDA  for clinical applications. However, this polymer has poor cell attachment property. In this study, Kr⁺ was irradiated into the PLGA mesh to improve its biocompatibility.

Kr⁺-irradiation was performed to the mesh at an energy of 50 keV with fluences between 1E13 to 1E15 ions/cm². The breakage of original chemical bonds by the irradiation was studied by Fourier transform infrared spectroscopy (FT-IR-ATR). Tensile strength and hydrolytic degradation behavior in phosphate buffer solution (PBS) were investigated. Fibroblast cells (L929) were seeded on non-irradiated and irradiated meshes. To evaluate biocompatibility, PLGA meshes were wrapped around the carotid artery with fibrin glue in Japanese white rabbits.

Kr⁺-irradiation leads to the scission of original chemical bonds. Tensile strength of the meshes decreased with the fluence increased. The weight of irradiated meshes decreased as time passed in the same manner as non-irradiated mesh. Irradiated layer with a fluence of 1E15 ions/cm² was exfoliated from the meshes in PBS solution due to the large radiation damage. Ion beam irradiation at lower fluence is more suitable condition. From in vitro cell studies, the cell attachment was improved by Kr⁺-irradiation. In animal study, irradiated mesh showed excellent tissue compatibility and inhibited an excess of cell proliferation around blood vessel. At 4 weeks, irradiated mesh degraded in vivo.

Kr⁺-irradiated PLGA meshes had excellent tissue compatibility and retained biodegradability. The meshes will be useful as wrapping materials for clinical application.