Controlled degradation of nanoporous silicon particles by selectively tuning pore size & porosity
J.O. Martinez, E. Tasciotti, C. Chiappini, X. Liu, M. Ferrari
The University of Texas Health Science Center, US
Keywords: drug delivery, degradation, nanoporous, nanovector delivery, nanomedicine
Abstract:This system is based on nanoporous silicon (NPS) particles of defined size and shape with tunable pore size (5-150 nm) and porosities (30-80%) that have been mathematical derived to bypass biobarriers. In this abstract we present the data relative to the degradation of four distinct particle types presenting different physico-chemical properties. By applying several characterization methods such as Inductively Coupled Plasma – Atomic Emission Spectroscopy (ICP-AES), Scanning Electron Microscopy (SEM), flow cytometry, zeta potential and a cell and particle counter and sizer, we observed that the degradation of these NPS particles correlated with its pore size and porosity resulting in rates that were unique to each particle. Comparing SEM images with ICP-AES analysis, we show that NPS particles degrade such that the highly porous ring is the first main feature to disappear, allowing for increased surface area and decreasing the amount of bulk silicon which induces a higher porosity within the structure and essentially decreases the amount of time till the particle becomes completely degraded. Thus, by tuning the porosity of the microparticles one can control the rate of degradation and potentially optimize the release of nanovectors and tailoring the pharmacokinetics of the drug inside them.