Poly(p-phenylenevinylene) functionalized fluorescent mesoporous silica nanoparticles for drug release and cell imaging

A fluorescent conjugated polymer of poly(p-phenylenevinylene) (PPV) was incorporated into the mesoporous silica nanoparticles (MSNs) by an ion-exchange and in situ polymerization route. The PPV functionalized MSNs were further coated with a layer of mesoporous silica shell to form the core-shell MSNs (PPV@MSN@nSiO₂@mSiO₂) by the controlled hydrolysis and condensation of silica precursor combining the in situ sol-gel process. The obtained fluorescent MSNs containing PPV were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N₂ adsorption/desorption and photoluminescence (PL) spectra. The results indicated that the novel containing-PPV MSNs had a diameter range of about 45-120 nm and a strong PL emission at 520 nm with a high fluorescent quantum yield (QY) up to 71%. The mesoporous features of fluorescence MSNs with or without core-shell structure imparted the capabilities of loading and releasing drug with a relatively high loading efficiency and a sustained release behavior of drugs. The investigations showed that these samples had a slow release effect of ibuprofen (IBU). In addition, the novel fluorescent MSNs were used in the in vitro researches of the imaging for human cervical cancer cells (HeLa).