Nanoporous thin-film samples, fabricated from degradable block copolymers, polystyrene-b-poly(l-lactide) (PS-PLLA), were utilized as templates for the formation of ordered nanoarrays. This work elucidates the feasibility of using such nanoporous PS templates as coatings on implantable devices for drug delivery through pore-filling sirolimus. Specific pore-filling process was adopted to increase loading efficiency by exploiting the capillary force associated with the tunable wetting property of the sirolimus solution. After the pore-filling process, sirolimus-loaded cylindrical and lamellar nanoarrays can be obtained. A comparison with those of macroscale templates indicates that the developed nanoporous templates can successfully entrap the loaded drug in nanoscale pores, markedly increasing the duration of drug delivery. As a result, the size, geometry, and depth of the nanoscale pores of the nanoporous templates can be readily controlled to regulate the drug release profiles.

International audienceThis work presents a simple method to generate ordered conjugated polymer nanoarrays through a pore-filling process for nanoporous polymer templates so as to enhance the efficiency of photoluminescence (PL). PL results combined with the morphological evolution examined by scanning probe microscopy revealed that the enhanced PL reaches maximum intensity as the template pores are completely filled by conjugated polymers. Polarized PL spectroscopy and grazing incidence Fourier transform infrared spectroscopy were used to determine the chain orientation of templated conjugated polymer; the spectroscopic results indicate a parallel chain orientation along the cylindrical direction of nanopores. The induced alignment of the polymer chains is attributed to a nanoscale spatial effect that increases the PL intensity and the lifetime of the conjugated polymer. The enhanced luminescence of nanostructured conjugated polymers is highly promising for use in designing luminescent nanodevices

This work presents a simple method to generate ordered chromophore/dispersant nanoarrays through a pore-filling process for a nanoporous polymer template to enhance chromophore luminescence. Fluorescence results combining with the morphological evolution examined by scanning probe microscopy reveal that the enhanced luminescence intensity reaches the maximum intensity as the nanopores of the template are completely filled by the chromophore/dispersant mixture. The variation is attributed to nanoscale spatial effect on the enhanced mixing efficiency of chromophore and dispersant, that is, the alleviation of self-quenching problem, as evidenced by the results of attenuated total reflection Fourier transform IR spectroscopy combining with grazing incident wide-angle X-ray diffraction. The enhanced luminescence of the chromophore/dispersant nanoarrays driven by the nanoscale spatial effect is highly promising for use in designing luminescent nanodevices.