functional inks; in this way, substrates may be patterned with functional materials and tailored nanoparticle arrays may be generated. An ideal additive lithographic substrate patterning technique would allow the execution of an unlimited number of parallel large-area ink deposition steps characterized by short cycle times without process-intrinsic interruptions caused, for example, by ink depletion. However, stateof-the-art substrate patterning techniques do not meet this requirement. Contactless ballistic pattering methods including inkjet printing, aerosol jet printing [2] and laser-induced forward transfer [3] can, in principle, be carried out continuously because ink can continuously be supplied to the substrate. However, these methods involve serial pixel-by-pixel writing associated with limitations regarding patternable areas and/or throughput. Additive substrate patterning by microcontact printing [4] and variations thereof such as polymer pen lithography (PPL), [5] capillary force lithography, [6] wet lithography, [7] and particle transfer printing [8] are parallel and allow simultaneous patterning of large substrate areas. However, these methods involve transfer of ink coated on the outer surfaces of solid elastomeric stamps to substrates. Consequently, ink depletion in the course of successive stamp-substrate contacts results in deteriorating quality of the stamped patterns. Automated stamping devices for parallel additive surface manufacturing would be commercially available, [9] but stamping needs to be interrupted after a limited number of stamping steps to recoat Patterned substrates for optics, electronics, sensing, lab-on-chip technologies, bioanalytics, clinical diagnostics as well as translational and personalized medicine are typically prepared by additive substrate manufacturing including ballistic printing and microcontact printing. However, ballistic printing (e.g., ink jet and aerosol jet printing, laser-induced forward transfer) involves serial pixelby-pixel ink deposition. Parallel additive patterning by microcontact printing is performed with solid elastomeric stamps suffering from ink depletion after a few stamp-substrate contacts. The throughput limitations of additive stateof-the art patterning thus arising may be overcome by capillary stampingparallel additive substrate patterning without ink depletion by mesoporous silica stamps, which enable ink supply through the mesopores anytime during stamping. Thus, either arrays of substrate-bound nanoparticles or colloidal nanodispersions of detached nanoparticles are accessible. Three types of model inks are processed: 1) drug solutions, 2) solutions containing metallopolymers and block copolymers as well as 3) nanodiamond suspensions representing colloidal nanoparticle inks. Thus, aqueous colloidal nanodispersions of stamped drug nanoparticles, regularly arranged ceramic nanoparticles by post-stamping pyrolysis of stamped metallopolymeric precursor nanoparticles and regularly arranged nanodiamond nanoaggregates are obtained. Capillary sta...

Qualitative and quantitative analysis of transient signaling platforms in the plasma membrane has remained a key experimental challenge. Here, biofunctional nanodot arrays (bNDAs) are developed to spatially control dimerization and clustering of cell surface receptors at the nanoscale. High-contrast bNDAs with spot diameters of 300 nm are obtained by capillary nanostamping of bovine serum albumin bioconjugates, which are subsequently biofunctionalized by reaction with tandem anti-green fluorescence protein (GFP) clamp fusions. Spatially controlled assembly of active Wnt signalosomes is achieved at the nanoscale in the plasma membrane of live cells by capturing the co-receptor Lrp6 into bNDAs via an extracellular GFP tag. Strikingly, co-recruitment is observed of co-receptor Frizzled-8 as well as the cytosolic scaffold proteins Axin-1 and Disheveled-2 into Lrp6 nanodots in the absence of ligand. Density variation and the high dynamics of effector proteins uncover highly cooperative liquid-liquid phase separation (LLPS)-driven assembly of Wnt "signalodroplets" at the plasma membrane, pinpointing the synergistic effects of LLPS for Wnt signaling amplification. These insights highlight the potential of bNDAs for systematically interrogating nanoscale signaling platforms and condensation at the plasma membrane of live cells.

No abstract

Qualitative and quantitative analysis of transient signaling platforms in the plasma membrane has remained a key experimental challenge. Here, we have developed biofunctional nanodot arrays (bNDAs) to spatially control dimerization and clustering of cell surface receptors at nanoscale. High-contrast bNDAs with spot diameters of ~300 nm were obtained by capillary nanostamping of BSA conjugated with the HaloTag ligand, which were subsequently biofunctionalized by reaction of a tandem anti-GFP clamp fused to the HaloTag. We achieved spatially controlled assembly of active Wnt signalosomes at the nanoscale in the plasma membrane of live cells by capturing the co-receptor Lrp6 into bNDAs via an extracellular GFP tag. Strikingly, we observed co-recruitment of co-receptor Frizzled-8 as well as the cytosolic scaffold proteins Axin-1 and Disheveled-2 into Lrp6 nanodots in the absence of ligand. Density variation and the high dynamics of effector proteins uncover highly cooperative liquid-liquid phase separation (LLPS)-driven assembly of Wnt signalodroplets at the plasma membrane. These insights highlight the potential of bNDAs for systematically interrogating nanoscale signaling platforms and condensation at the plasma membrane of live cells.