Vapor-Deposited Nanocoatings for Sustained Zero-Order Release of Antiproliferative Drugs

Abstract

Drug-eluting stents have been widely used in the treatment of coronary heart diseases, but the long-term efficacy has been dependent on the control of drug release kinetics. Though evenly distributed release with minimal burst release is much desired for the antiproliferative drugs used on stents, strategies for sustained zero-order release have not been specifically identified. We investigated vapor-based fabrication of polymer nanocoatings for the encapsulation of antiproliferative drugs. Drug release kinetics was regulated by adjusting the composition and thickness of the nanocoatings. Zero-order release of atorvastatin and sirolimus for 30 days was achieved using a poly­(2-dimethylamino ethyl methacrylate-co-ethylene glycol diacrylate) (PDE) nanocoating with a monomer/cross-linker molar ratio of 0.78. The drug release rate was modulated using drug dose and coating thickness. The combination of coating surface and drug release suppressed the viability and proliferation of human coronary artery smooth muscle cells to below 57% at dose density as low as 10 μg/cm2. The PDE nanocoatings also reduced surface platelet adhesion without detrimental effect on red blood cells. The findings of this study demonstrate the potential of applying vapor-deposited polymer nanocoatings in modulating the release kinetics and thus improving the therapeutic efficacy of drug-eluting stents.

Surface Tailoring of 3D Scaffolds to Promote Osteogenic Differentiation

“…Both the 220 μm interconnected channels and the nanoporous structure inside the rods of the PMDE-scaffold were preserved. This outcome is attributed to the ability of the iCVD process to coat micro- and nanostructure conformally . The presence of the PMDE coating was confirmed by comparing the ATR-FTIR spectra of the pristine scaffold and PMDE-scaffold in Figure D.…”

“…This outcome is attributed to the ability of the iCVD process to coat micro-and nanostructure conformally. 23 The presence of the PMDE coating was confirmed by comparing the ATR-FTIR spectra of the pristine scaffold and PMDE-scaffold in Figure 2D. While the absorption peaks at 910−1190 and 3572 cm −1 were assigned to the phosphate and hydroxyl groups in HA, respectively, 37 the peaks at 1730−1735 cm −1 were attributed to the C�O stretching of MAA, DMAEMA, and EGDA moieties in the PMDE coating, and the broad absorption band in the range of 3050−3500 cm −1 was attributed to the O−H stretching of the MAA moiety.…”

“…Plasma polymerization has been reported to generate coatings rich in amine and carboxyl functionalities to improve osteogenesis on 3D scaffolds. − However, the monomer fragmentation in the plasma processes reduced the incorporation of desired functionality , and led to nonuniform distribution of functional groups, which limited the osteogenic potential of the coated surface. Initiated chemical vapor deposition (iCVD) enables deposition of polymer coatings with full retention of functional groups, owing to the selective decomposition of an initiator species to start the polymerization of monomers. − Recently, we discovered that polyelectrolyte coatings deposited by iCVD improved the osteoinductivity of planar surfaces, and the polyelectrolyte coating with mixed charges exhibited the potential to induce mineralization similar to natural collagen fibril …”

“…We use a printed hydroxyapatite scaffold as a model 3D scaffold. Since iCVD coating is not limited to a specific material or geometry, the formation of apatites on vapor-deposited polyelectrolytes can be applied on any bone scaffolds. Our hypothesis is that the modified scaffolds provide both chemical and physical cues for preosteoblasts to grow and differentiate .…”

Solventless Polymer-Grafted Mesh for Rapid and Efficient Oil–Water Separation

“…This characteristic of minimal morphology change was attributed to the conformal nature of the iCVD process and the ultrathin thickness of the nanocoating. 45,56 3.2. Oil−Water Separation Performance.…”