Combined cerium oxide nanocapping and layer-by-layer coating of porous silicon containers for controlled drug release

Local drug release in close vicinity of solid tumors is a promising therapeutic approach in cancer therapy. Implantable drug delivery systems can be desi gned to achieve contr olled and sustained drug release. In this study, ultrath in porous membranes of silicon wafer were employed as compatib le drug reser voir models. An antica ncer mo del drug, curcum in (CUR ), was successfully loaded into porous silicon containers (8.94 ± 0.72% w/w) , and then , ceriu m oxid e nanocappin g was per formed on the open pores for drug protection and release rate prolongation. Next , layer-by-layer surface coating of the drug container with anioni c (alginate) and cationic (chitosan) polymers rendered pH-re spon sivity to the device. The drug release pro fi le was studied using re fl ectometric interference Fourier transform spectroscopy at differen t pH condi tions. It was determined that faster decompositio n of the polymeric layer s and subsequent CUR release occur in acidic buffer (p H 5.5) compared to a neutral buffer. Var ious characterizatio n studies, including dynamic light scattering , Fourier transform infrared spectroscopy, scanning and transmission electron micro scopy, contac t angle measurement , ultraviolet-visib le spectrosco py, and X-ray powder diffraction revealed that our system has the required physicochemi cal properties to serve as a nove l pH-sen sitive drug delivery implan t for cancer therapy.