PEGylated stereocomplex polylactide coating of stent for upregulated biocompatibility and drug storage

- PEGylated stereocomplex polylactide is developed as a promising coating of coronary stent.
- The coating exhibits decreased fibrinogen adsorption, down-regulated platelet activation, and improved cytocompatibility.
- The stereocomplex polylactide coating serves as a sustained drug reservoir.
- The stereocomplex polylactide systems may be utilized as a promising platform for various biomedical applications.

Treatment of coronary heart disease by percutaneous coronary intervention (PCT) is usually limited to the high restenosis rate after implantation of bare-metal stent. To solve the problem, the coating of PEGylated stereocomplex poly(l-lactide) (PEG−cPLA) was utilized on the surface modification of stainless steel (SS) sheet. Specifically, the 3-aminopropyltriethoxysilane (APTES)-modified methoxy-poly(ethylene glycol)−poly(d-lactide) (mPEG−PDLA) was grafted onto the surface of hydroxylated SS sheet through coupling reaction, and poly(l-lactide)−poly(ethylene glycol)−poly(l-lactide) (PLLA−PEG−PLLA) was coated onto the surface through stereocomplex interaction between DLA and LLA units. The increase of contact angle firstly confirmed the changes of surface composition and hydrophilicity for the PEG−scPLA-modified SS sheet. The decreased fibrinogen adsorption, down-regulated platelet activation, and improved adhesion of human umbilical vein endothelial cells (HUVECs) indicated the excellent biocompatibility of PEG−scPLA-modified SS sheet. In addition, the drug loading capability of SS sheet was greatly upregulated through the formation of scPLA coating on the surface, where fluorescein (FLU) was chosen as a model molecule. Overall, the surface modification of SS sheet with PEG−scPLA could enhance the comprehensive performances, such as biocompatibility and drug loading capability, demonstrating that PEG−scPLA is a promising coating of coronary stent for PCT.

237