SummaryThe creation of an oral drug delivery platform to administer chemotherapeutic agents effectively can not only increase patient compliance, but also potentially diminish drug toxicity. A microfabricated device offers advantages over conventional drug delivery technology. Here we describe the development of a multi-layered polymeric drug-loaded microfabricated device (microdevice) for the oral delivery of therapeutics, which offers unidirectional release of multiple therapeutics. The imaging and release of therapeutics from the multi-layered device was performed with three different fluorescently labeled albumins. The release of insulin and chemotherapeutic camptothecin was also observed to be released in a controlled manner over the course of 180 minutes in vitro. Furthermore, asymmetric delivery was shown to concrete drug at the device/cell interface, wherein 10 times more drug permeated an intestinal epithelial cell monolayer, compared to unprotected drug-loaded hydrogels. The bioactivity of the released chemotherapeutic was shown with cytostasis of colorectal adenocarcinoma cells. Cytostasis of drug loaded hydrogels was significantly higher than control empty hydrogel laden microdevices. Our results conclude that microfabrication of a hydrogel laden microdevice leads to a viable oral delivery platform for chemotherapeutics.

Linearly polarized attenuated total internal reflection (ATR) spectroscopy is used to study the adsorption properties of reduced cytochrome c to a silica surface. The adsorption equilibrium constant, surface coverage, protein orientation, effect of NaCl, and pH dependence are determined for the adsorption of reduced cytochrome c onto a silica surface. Surface coverage results (at pH 7.2) show that reduced cytochrome c packs onto the silica surface at <80% of a closely packed monolayer. The protein orientation distribution as measured by an order parameter is shown to be dependent on the surface coverage and solution pH. All of the results for the surface adsorption of reduced cytochrome c on silica are indicative of an electrostatically driven interaction. The results for reduced cytochrome c are compared to surface adsorption results for oxidized cytochrome c on silica. These results indicate that there is no significant difference in the adsorption behavior correlating to the oxidation state of this heme protein.