Preparation, characterization, and preliminary biocompatibility evaluation of particulate spin-coated mesoporous silica films

Porous, biocompatible supports are interesting substrates for biological applications, as they allow for release of actives with spatial control. Here we report on the synthesis and characterization of spin-coated thin films made of mesoporous silica nanoparticles of different size and shape on microscopy slides. By controlling processing parameters like spinning-speed and particle concentration, homogeneous films can be prepared with controlled thicknesses ranging from bilayers to several multilayers. Different particle diameters and shapes can be used, thus providing further parameters for film thickness and morphology control. The use of particles in the preparation of the spin-coated films has several advantages. Relatively homogeneous thick films can be prepared in one step with thicknesses exceeding those using molecular precursor solutions. Furthermore, as the morphological properties of the surface are known to influence cell attachment, proliferation, and also differentiation of stem cells, the possibility to influence the morphology of the films is highly attractive from a biomaterial perspective. Preliminary in vitro cell studies indicate that the particles can be endocytosed by cells cultivated on these films, and that model drugs can be released inside the cells showing the potential of these films for local drug delivery applications. The results are important for further optimization of novel scaffolds exhibiting spatial, and temporal control of the delivery of active cues in, for example, tissue engineering applications.