Fabrication of fluorescent silica nanoparticle-doped polycaprolactone composite film for cell labeling

Abstract

Stem cells possess property of self-renewable and can differentiate into specified cell types. Thus stem-cell based therapy holds promise and potential to cure some irremediable disease including diabetes, Parkinson disease, Alzheimer disease, cancer and etc. To understand the survival, migration, homing, differentiation and other functions of transplanted stem cells in the local microenvironment, cell tracking with modern imaging modalities are exploited. However, all these modalities suffer from signal dilution due to cellular cycle such as division, death and exocytosis. Thus it is important to provide continuous supply of contrast agents to maintain signal concentration to ensure that cells can be tracked longer and efficiently. To realize the desirable continuous supply of signal, the hypothesis is to incorporate the contrast agents into a biodegradable scaffold which could be consumed by cells seeding on it. In this project, fluorescent silica nanoparticles (NPs) were dispersed to finely-powdered polycaprolactone (PCL) and then thermally pressed to thin films. The fabricated films were cut into small round pieces and then were attached to glass coverslips for culturing two kinds of adherent cells and two kinds of suspended cells. Cultured cells are collected and percentage of labeled cells was calculated. Results show that the percentage of labeled adherent cells increased with time while suspension cells were unable to be labeled. This composite film could be used to selectively label adherent cells without any other modification and procedure.