Role of silica nanoparticles in monitoring and prolonging release of drug-eluting polyelectrolyte coatings using long-period fiber grating platform

- Synergistic integration of silica nanoparticles (SNPs) with long period grating (LPG) and drug-eluting polyelectrolyte thin films promotes dual functionality.
- SNPs on LPG acts as a suitable substrate to improve the sensitivity of the LPG.
- SNPs affords the ability to tune the release profiles by controlling the layer structures of the SNPs.

Silica nanoparticles (SNPs) were synergistically integrated with long-period grating (LPG) platform and the process of layer-by-layer (LbL) assembly to enable monitoring controlled release of drug-eluting polyelectrolyte coatings. The SNPs afforded a high surface area for increased drug loading as well as enhanced evanescent field overlap. In addition, the SNPs positioned within the LbL coatings acted as diffusion barrier layer, leading to prolonged release profile. SNPs with different sizes were respectively immobilized on the LPG using poly allylamine hydrochloride (PAH). In-situ monitoring of drug-eluting LbL coating [chitosan (CHI)/Poly arylic acid (PAA)/Gentamicin sulfate (GS)/PAA]n was carried out on LPG with a sensitivity of 8.1 nm shift/tetralayer for LPG with 1 layer of SNPs with 50 nm in diameter. LPG without the SNPs for the monitoring of [CHI/PAA/GS/PAA]n shows a sensitivity of 2.4 nm shift/tetralayer, indicating the significant ability of SNPs in enhancing the LPG sensitivity. Drug release measurement carried out on the LPG platform revealed an increased release time for LbL-SNP drug delivery system compared with that of LbL alone.