5,10,15,20-Tetrakis (4-carboxyphenyl) porphin-conjugated poly(l-lactic) acid/polyethylene oxide nanofiber membranes for photodynamic therapy

In this work, a poly(l-lactic) acid (PLLA)/polyethylene oxide (PEO) nanofiber membrane was prepared by electrospinning as a carrier for the photosensitizer 5,10,15,20-tetrakis (4-carboxyphenyl) porphin (TCPP) to study the effects of singlet oxygen ( 1 O 2 ) on tumor cells. Scanning electron microscopy and confocal laser scanning microscopy images showed that the fiber surface was smooth and that TCPP was evenly dispersed in the nanofibers. TCPP, PLLA, and PEO were mixed with nanofibers without the formation of new chemical bonds, as shown by Fourier transform infrared spectroscopy. The addition of PEO improved the hydrophilicity of the nanofibers, making the contact angle of the PLLA nanofiber membrane change from 93.3° to near 0° and resulting in good cell compatibility. The sustained release experiment showed that when the amount of TCPP was 3%, the cumulative release concentration after 72 h was close to saturation in the test system. Electron spin resonance spectroscopy confirmed that TCPP produced 1 O 2 at light irradiation (532 nm). The results of in vitro cell experiments showed that TCPP@PLLA/PEO nanofiber membranes did not affect the normal growth of HeLa cells but had cytotoxic effects on cancer cells under light irradiation.