Towards a single bioactive substrate combining SERS-effect and drug release control based on thin anodic porous alumina
- PDF / 1,022,093 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 35 Downloads / 156 Views
Towards a single bioactive substrate combining SERS-effect and drug release control based on thin anodic porous alumina coated with gold and with lipid bilayers Amirreza Shayganpour1,2§, Marco Salerno1§, Barbara Salis1,2, Silvia Dante1 1 Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, I-16163 Genova, Italy 2 Department of Bioengineering and Robotics, University of Genova, viale Causa 13, I-16145 Genova, Italy § these two authors have equally contributed to the work ABSTRACT Thin anodic porous alumina (tAPA), engineered by electrochemical anodization of aluminum and post-fabrication etching, has already shown surface-enhanced Raman scattering (SERS) activity, after overcoating with a thin gold film. On the other hand, the tAPA nanoporous surface, which is biocompatible and presents controlled roughness, has been extensively investigated as a substrate for living cell cultures. Here, we are interested in exploiting the nanoporosity of tAPA as a drug reservoir and demonstrating drug-delivery capabilities of these substrates which can be combined with the above cell-seeding and SERS activities. We focused on the loading/elution of a test drug, the nonsteroidal anti-inflammatory and analgesic molecule Diclofenac. We carried out pore loading of differently concentrated aqueous solutions of the test drug, and characterized the elution profiles by UV-Vis absorbance, using the lipid bilayers coated on the top surface as a mechanism for retarded elution from the pores, providing a more sustained release. We also demonstrated that, by changing an environmental parameter such as the pH, we can trigger an increased release of the drug. Additionally, we investigated the tAPA adsorption properties by quartz crystal microbalance technique with dissipation monitoring (QCM-D). For the purpose, anodization was carried out on an Al-coated quartz, which resulted in successful fabrication of tAPA on the sensor. Finally, the process of lipid bilayer formation on the nanoporous sensor, as well as the test drug loading, was demonstrated by QCM-D.
INTRODUCTION Several studies already exist on the potential of APA in particular for its biomedical [1][2] and sensing applications [3][4][5]. The large surface area of APA in comparison to other materials with flat surfaces improves the sensitivity of APA-based sensing devices and is considered as a major advantage in their application. For instance, a recent work of Losic group demonstrated application of APA for spectroscopy based on reflectometric interference, aiming to detect gastrointestinal enzymes including chymotrypsin and horseradish peroxidase, which seems promising for use as a point-of-care system for fast detection of gastrointestinal diseases at early stages [6]. In parallel to the use as cell-seeding substrate and sensing surface, APA can have its pores exploited as nanocontainers for drug storage and subsequent release (drugdelivery) [7][8]. Biocompatibility and drug delivery properties of APA can be optimized by surface modifications such as conformal
Data Loading...
