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Efficient intracellular drug delivery in nanomedicine strongly depends on ways to induce cellular uptake. Conjugation of nanoparticles (NPs) with cell-penetrating peptides (CPPs) is a known means to induce uptake via endocytosis. Here, we functionalized NPs consisting of either poly(D,L-lactide-co-glycolide) (PLGA) or polyethene glycol (PEG)-PLGA block-copolymer with a lactoferrin-derived cell-penetrating peptide (hLF). To enhance the association between the peptide and the polymer NPs, we tested a range of acyl moieties for N-terminal acylation of the peptide as a means to promote noncovalent interactions. Acyl moieties differed in chain length and number of acyl chains. Peptide-functionalized NPs were characterized for nanoparticle size, overall net charge, storage stability, and intracellular uptake. Coating particles with a palmitoylated hLF resulted in minimal precipitation after storage at −20C and homogeneous particle size (

An effective and low-cost method to fabricate hexagonally patterned, vertically aligned Si/Ge superlattice nanowires with diameters below 20 nm is presented. By combining the growth of Si/Ge superlattices by molecular beam epitaxy, prepatterning the substrate by anodic aluminum oxide masks, and finally metal-assisted chemical wet etching, this method generates highly ordered hexagonally patterned nanowires. This technique allows the fabrication of nanowires with a high area density of 10(10) wires/cm(2), including the control of their diameter and length.

Ordered nanofiber arrays are a promising material platform for artificial adhesive structures, tissue engineering, wound dressing, sensor arrays, and self-cleaning surfaces. Their production via self-ordered porous alumina hard templates serving as shape-defining molds is well-established. However, their release requires the destruction of the hard templates, the fabrication of which is costly and time-consuming, by wet-chemical etching steps with acids or bases. We report the nondestructive mechanical extraction of arrays of cross-linked polyacrylate nanofibers from thus recyclable self-ordered nanoporous alumina hard templates. Silica replicas of the latter were synthesized using the extricated nanofiber arrays as secondary molds that could be mechanically detached from the molded material. The approach reported here, which can be combined with microstructuring, may pave the way for the high-throughput production of both functional nanofiber arrays and ordered nanoporous membranes consisting of a broad range of material systems.

The fabrication of one-dimensional (1D) nanostructures and microstructures inside the pores of porous templates is intensively investigated. The release of these structures is commonly accomplished by etching and destroying the templates. The 1D nanostructures and microstructures tend to condense because of the occurrence of capillary forces during drying of the specimens. It is shown that highly ordered arrays of polymer microfibers can be easily detached from silanized porous templates by mechanical lift-off. This procedure leaves the templates intact, thus allowing their recycling, and does not involve the use of solutions or solvents, thus circumventing condensation. Therefore, mechanical lift-off may enable the up-scaling of template-based approaches to the fabrication of highly ordered assemblies of 1D nanostructures and microstructures.

Mesoporous silica monoliths containing arrays of aligned macropores oriented perpendicular to their surfaces were prepared by non-destructive imprinting of sol/gels with polymer nanorod arrays. Crack-free monoliths with areas of up to 2.5 cm2 were obtained by a combination of slow drying under ambient conditions and optimized freeze-drying.

Biodegradable extracellular matrices (ECMs) consisting of mechanically stable arrays of aligned poly(lactide) nanorods (nanorod diameter ≈ 200 nm; lattice constant ≈ 500 nm) with areas up to 9 cm2 were prepared by nondestructive extraction from recyclable self-ordered nanoporous alumina hard templates. Fibroblasts formed dense tissue layers on the heparin/gelatin activated nanorod arrays, showed excellent adhesion and exhibited a highly elongated morphology such as in natural tissue. The synthetic approach reported here combining advantages of top-down lithography (well-defined topography) and self-assembly (low costs, high throughput, feature size in the 100 nm range) may yield ECMs for biomedical applications. Remarkably, on microrod arrays with four times larger feature sizes the fibroblasts were significantly less elongated and their proliferation was strongly reduced.