NIR-Emitting Gold Nanoclusters Encapsulated in PS-b-PEG Polymer Micelles.

Gold nanoclusters (AuNCs) are an emerging type of luminescent probe, featuring good biocompatibility, high photostability, and large Stoke shifts. Their lack of colloidal stability is, however, a drawback for many applications. Here, we report the stabilization of AuNCs emitting in the NIR by a thiol-terminated polystyrene chain (Mn = 5000 g mol-1). The optical properties of this nanocomposite remain invariant for 2 years in THF. To use the PS5k-AuNCs in an aqueous environment, these were encapsulated into polymer micelles using a polystyrene-b-poly(ethylene glycol) copolymer. The resulting hierarchical constructs, with diameters of ca. 125 to 215 nm, have promising properties for applications as luminescent probes such as contrast agents for biomedical imaging.

Effects of Microfluidic Shear on the Plasmid DNA Structure: Implications for Polymeric Gene Delivery Vectors.

Microfluidic manufacturing of advanced gene delivery vectors necessitates consideration of the effects of microfluidic shear forces on the structural integrity of plasmid DNA (pDNA). In this paper, we expose pDNA to variable shear forces in a two-phase, gas-liquid microfluidic reactor and apply gel electrophoresis to analyze the products of on-chip shear-induced degradation. The effects of shear rate, solvent environment, pDNA size, and copolymer complexation on shear-induced degradation are investigated. We find that small naked pDNA (pUC18, 2.7 kb) exhibits shear rate-dependent shear degradation in the microfluidic channels in a mixed organic solvent (dioxane/water/acetic acid; 90/10/<0.1 w/w/w), with the extents of both supercoil isoform relaxation and complete fragmentation increasing as the maximum shear rates increase from 4 × 105 to 2 × 106 s-1. However, over the same range of shear rates, the same pDNA sample shows no evidence of microfluidic shear-induced degradation in a pure aqueous environment. Quiescent control experiments in the same mixed organic solvent prove that a combination of solvent and shear forces is involved in the observed shear-induced degradation. Furthermore, we show that shear degradation effects in mixed organic solvents can be significantly attenuated by complexation of pDNA with the block copolymer polycaprolactone-block-poly(2-vinylpyridine) prior to exposure to microfluidic shear. Finally, we demonstrate that medium (pDSK519, 8.1 kb) and large (pRK290, 20 kb) naked pDNA are more sensitive to shear-induced microfluidic degradation in the mixed organic solvent environment than small pDNA, with both plasmids showing complete fragmentation even at the lowest shear rate, although we found no evidence of shear-induced damage in water for the largest investigated naked pDNA even at the highest flow rate. The resulting understanding of the interplay of the solvent and shear effects during microfluidic processing should inform microfluidic manufacturing routes to new gene therapy formulations.

Enhancement of cellular uptake by increasing the number of encapsulated gold nanoparticles in polymeric micelles.

We apply a combination of polycaprolactone (PCL)-thiol ligand functionalization with flow-controlled microfluidic block copolymer self-assembly to produce biocompatible gold nanoparticle (GNP)-loaded micellar polymer nanoparticles (GNP-PNPs) in which GNPs are encapsulated within PCL cores surrounded by an external layer of poly(ethylene glycol) (PEG). By varying both the relative amount of block copolymer and the microfluidic flow rate, a series of GNP-PNPs are produced in which the mean number of GNPs per PNP in the < 50-nm fraction (Zave,d< 50 nm) varies between 0.1 and 1.9 while the external PEG surface is constant. Zave,d< 50 nm values are determined by statistical analysis of TEM images and compared with the results of cell uptake experiments on MDA-MB-231 cancer cells. For Zave,d< 50 nm ≤ 1 (including a control sample of individual GNPs also with a PEG surface layer), cell uptake is relatively constant, but increases sharply for Zave,d< 50 nm > 1, with a factor of 7 enhancement as Zave,d< 50 nm increases from 1 to ∼2. Enabled by the shear processing control provided by the microfluidic chip, these results provide the first evidence that cellular uptake can be enhanced specifically by increasing the number of GNPs per vector, with other parameters, including polymeric material, internal structure, and external surface chemistry, held constant. They also demonstrate a versatile platform for packaging GNPs in biocompatible polymeric carriers with flow-controlled formulation optimization for various therapeutic and diagnostic applications.

Improvements in Drug-Delivery Properties by Co-Encapsulating Curcumin in SN-38-Loaded Anticancer Polymeric Nanoparticles.

SN-38 is an immensely potent anticancer agent although its use necessitates encapsulation to overcome issues of poor solubility and stability. Since SN-38 is a notoriously challenging drug to encapsulate, new avenues to increase encapsulation efficiency in polymer nanoparticles (PNPs) are needed. In this paper, we show that nanoprecipitation with curcumin (CUR) increases SN-38 encapsulation efficiencies in coloaded SN-38/CUR-PNPs based on poly(ε-caprolactone)-block-poly(ethylene glycol) (PCL-b-PEG) by up to a factor of 10. In addition, we find a dramatic decrease in PNP polydispersities, from 0.34 to 0.07, as the initial CUR-to-polymer ratio increases from 0 to 10, with only a modest increase in PNP size (from 40 to 55 nm). Compared to coloaded PNP formation using nanoprecipitation in the bulk or in a gas-liquid, a two-phase microfluidic reactor shows similar trends with respect to CUR content, although improvements in SN-38 encapsulation efficiencies both with and without CUR are found using the microfluidic method. Additional precipitation studies without copolymer suggest that CUR increases the dispersion of SN-38 in the solvent medium of micelle formation, which may contribute to the observed encapsulation enhancement. Cytotoxicity studies of unencapsulated SN-38/CUR mixtures show that addition of CUR does not significantly affect SN-38 potency against either U87 (glioblastoma) or A204 (rhabdomyosarcoma) cell lines. However, we find significant differences in the potencies of SN-38/CUR-PNP formulations depending on initial CUR amounts, with an optimized formulation showing subnanomolar cytotoxicity against A204 cells, significantly more potent than either free SN-38 or PNPs containing only SN-38.

Microfluidic Shear Processing Control of Biological Reduction Stimuli-Responsive Polymer Nanoparticles for Drug Delivery.

We demonstrate microfluidic manufacturing of glutathione (GSH)-responsive polymer nanoparticles (PNPs) with controlled in vitro pharmacological properties for selective drug delivery. This work leverages previous fundamental work on microfluidic control of the physicochemical properties of GSH-responsive PNPs containing cleavable disulfide groups in two different locations (core and interface, DualM PNPs). In this paper, we employ a two-phase gas-liquid microfluidic reactor for the flow-directed manufacturing of paclitaxel-loaded or DiI-loaded DualM PNPs (PAX-PNPs or DiI-PNPs, where DiI is a fluorescent drug surrogate dye). We find that both PAX-PNPs and DiI-PNPs exhibit similar flow-tunable sizes, morphologies, and internal structures to those previously described for empty DualM PNPs. Fluorescent imaging of DiI-PNP formulations shows that microfluidic manufacturing greatly improves the homogeneity of drug dispersion within the PNP population compared to standard bulk microprecipitation. Encapsulation of PAX in DualM PNPs significantly increases its selectivity to cancerous cells, with various PAX-PNP formulations showing higher cytotoxicity against cancerous MCF-7 cells than against non-cancerous HaCaT cells, in contrast to free PAX, which showed similar cytotoxicity in the two cell lines. In addition, the characterization of DualM PNP formulations formed at various microfluidic flow rates reveals that critical figures of merit for drug delivery function-including encapsulation efficiencies, GSH-triggered release rates, rates of cell uptake, cytotoxicities, and selectivity to cancerous cells-exhibit microfluidic flow tunability that mirrors trends in PNP size. These results highlight the potential of two-phase microfluidic manufacturing for controlling both structure and drug delivery function of biological stimuli-responsive nanomedicines toward improved therapeutic outcomes.

Controlled Microfluidic Synthesis of Biological Stimuli-Responsive Polymer Nanoparticles.

Microfluidic flow-directed self-assembly of biological stimuli-responsive block copolymers is demonstrated with dual-location cleavable linkages at the junction between hydrophilic and hydrophobic blocks and on pendant group within the hydrophobic blocks. On-chip self-assembly within a two-phase microfluidic reactor forms various "DualM" polymer nanoparticles (PNPs), including cylinders and multicompartment vesicles, with sizes and morphologies that are tunable with manufacturing flow rate. Complex kinetically trapped intermediates between shear-dependent states provide the most detailed mechanism to date of microfluidic PNP formation in the presence of flow-variable high shear. Glutathione (GSH)-triggered changes in PNP size and internal structure depend strongly on the initial flow-directed size and internal structure. Upon incubation in GSH, flow-directed PNPs with smaller average sizes showed a faster hydrodynamic size increase (attributed to junction cleavage) and those with higher excess Gibbs free energy showed faster inner compartment growth (attributed to pendant cleavage). These results demonstrate that the combination of chemical control of the location of biologically responsive linkages with microfluidic shear processing offers promising routes for tunable "smart" polymeric nanomedicines.

Structural hierarchy in blends of amphiphilic block copolymers self-assembled at the air-water interface.

We present a concurrent self-assembly strategy for patterning hierarchical polymeric surface features by depositing variable-composition blends of polystyrene-block-poly(ethylene oxide) (PS-b-PEO) and polybutadiene-block-poly(ethylene oxide) (PB-b-PEO) block copolymers at the air-water interface. Hierarchical strand networks of hydrophobic PS/PB blocks anchored via PEO blocks to the water surface, with an internal phase-separation structure consisting of periodic domains of PS blocks surrounded and connected by a matrix of PB blocks, are generated by the interplay of interfacial amphiphilic block copolymer aggregation and polymer/polymer phase separation. In contrast to the cylinder-in-strand structures previously formed by our group in which interfacial microphase separation between PS and PB blocks was constrained by chemical connectivity between the blocks, in the current system phase separation between PS and PB is not constrained by chemical connectivity and yet is confined laterally within surface features at the air-water interface. Investigations of multi-component polymer systems with different connectivities constraining repulsive and attractive interactions provides routes to new hierarchical surface patterns for a variety of applications, including photolithography masks, display technology, surface-guided cell growth and tissue engineering.

Microfluidic Manufacturing of SN-38-Loaded Polymer Nanoparticles with Shear Processing Control of Drug Delivery Properties.

Two-phase gas-liquid microfluidic reactors provide shear processing control of SN-38-loaded polymer nanoparticles (SN-38-PNPs). We prepare SN-38-PNPs from the block copolymer poly(methyl caprolactone- co-caprolactone)- block-poly(ethylene oxides) (P(MCL- co-CL)- b-PEO) using bulk and microfluidic methods and at different drug-to-polymer loading ratios and on-chip flow rates. We show that, as the microfluidic flow rate ( Q) increases, encapsulation efficiency and drug loading increase and release half times increase. Slower SN-38 release is obtained at the highest Q value ( Q = 400 µL/min) than is achieved using a conventional bulk preparation method. For all SN-38-PNP formulations, we find a dominant population (by number) of nanosized particles (<50 nm) along with a small number of larger aggregates (>100 nm). As Q increases, the size of aggregates decreases through a minimum and then increases, attributed to a flow-variable competition of shear-induced particle breakup and shear-induced particle coalescence. IC25 and IC50 values of the various SN-38-PNPs against MCF-7 cells show strong flow rate dependencies that mirror trends in particle size. SN-38-PNPs manufactured on-chip at intermediate flow rates show both minimum particle sizes and maximum potencies with a significantly lower IC25 value than the bulk-prepared sample. Compared to conventional bulk methods, microfluidic shear processing in two-phase reactors provides controlled manufacturing routes for optimizing and improving the properties of SN-38 nanomedicines.

Microfluidic Processing Approach to Controlling Drug Delivery Properties of Curcumin-Loaded Block Copolymer Nanoparticles.

We apply gas-liquid microfluidic reactors containing flow-variable, high-shear "hot spots" to produce curcumin-loaded polymer nanoparticles (CUR-PNPs) comprised of poly(caprolactone)- block-poly(ethylene oxide) (PCL- b-PEO) block copolymers at various flow rates and CUR loading ratios. CUR-PNPs prepared using the conventional nanoprecipitation method (bulk method) showed decreased encapsulation efficiency and increased drug precipitation as the loading ratio increased. However, CUR-PNPs prepared by microfluidic manufacturing showed both increased encapsulation efficiency and increased drug loading as either the flow rate or the loading ratio increased. This enabled microfluidic CUR loading percentages of up to 30% to be achieved in this study, which to our knowledge is a record for block copolymer PNPs. As well, it is shown that increased flow rate of microfluidic manufacturing leads to decreased mean CUR-PNP sizes (down to ∼50 nm) and narrower size distributions, along with significantly different CUR release kinetics compared to CUR-PNPs prepared at slower flow rates. In vitro antiproliferation experiments against MDA-MB-231 cells give an average IC50 value of 24 µM for CUR-PNPs compared to 13 µM for free CUR at the same incubation time of 72 h. Compared to conventional bulk and single-phase microfluidic strategies, this unique two-phase reactor represents an exciting manufacturing platform for optimizing polymeric CUR nanomedicines though flow-directed shear processing.

Amphiphilic Quantum Dots with Asymmetric, Mixed Polymer Brush Layers: From Single Core-Shell Nanoparticles to Salt-Induced Vesicle Formation.

A mixed micelle approach is used to produce amphiphilic brush nanoparticles (ABNPs) with cadmium sulfide quantum dot (QD) cores and surface layers of densely grafted (σ = ~1 chain/nm²) and asymmetric (fPS = 0.9) mixed polymer brushes that contain hydrophobic polystyrene (PS) and hydrophilic poly(methyl methacrylate) (PMAA) chains (PS/PMAA-CdS). In aqueous media, the mixed brushes undergo conformational rearrangements that depend strongly on prior salt addition, giving rise to one of two pathways to fluorescent and morphologically disparate QD-polymer colloids. (A) In the absence of salt, centrosymmetric condensation of PS chains forms individual core-shell QD-polymer colloids. (B) In the presence of salt, non-centrosymmetric condensation of PS chains forms Janus particles, which trigger anisotropic interactions and amphiphilic self-assembly into the QD-polymer vesicles. To our knowledge, this is the first example of an ABNP building block that can form either discrete core-shell colloids or self-assembled superstructures in water depending on simple changes to the chemical conditions (i.e., salt addition). Such dramatic and finely tuned morphological variation could inform numerous applications in sensing, biolabeling, photonics, and nanomedicine.

Effects of chemical and processing variables on paclitaxel-loaded polymer nanoparticles prepared using microfluidics.

For paclitaxel (PAX)-loaded polymeric nanoparticles PNPs prepared in a two-phase gas-liquid microfluidic reactor, the effects of microfluidic flow rate on the multiscale structure, loading efficiency and release rate are determined for three different copolymer compositions and two orders of magnitude variation in the PAX loading ratio. All experiments are carried out in the limit of low drug-to-polymer loading ratios (r≤0.01, w/w). In this range of r, PCL crystallinity, loading efficiency and release rate are not significantly affected by the amount of PAX dissolved in the core. These results are in sharp contrast to microfluidic PNPs prepared in a range of high loading ratios (r≥0.1), where the amount of added PAX has a strong influence on the multiscale structure and properties of drug delivery PNPs. For the case of r=0.01, we show that flow rate strongly affects PNP morphologies for all three block copolymer compositions. For the shortest and longest PCL block lengths, the relative number of cylindrical morphologies increases and then decreases with increasing flow rate, whereas for the intermediate PCL block length, the number of cylinders steadily increases as the flow rate increases. Internal PCL crystallinities and PAX loading efficiencies show similar trends, both parameters increasing and decreasing with increasing flow rate for the extreme PCL block lengths and steadily increasing for the intermediate PCL block length. PAX release profiles indicate a marked slowing of PAX release as either the PCL block length or the microfluidic flow rate increase. Working in the limit of low loading ratio, this work provides clarity on separating the relative effects of copolymer composition and processing along with perturbations caused by the molecular cargo on the structure and function of drug delivery PNPs. These critical insights thus inform controlled microfluidic preparation of more medically-relevant PNPs at higher therapeutic loading levels.

Versatile Tetrablock Copolymer Scaffold for Hierarchical Colloidal Nanoparticle Assemblies: Synthesis, Characterization, and Molecular Dynamics Simulation.

A unique combination of molecular dynamics (MD) simulation and detailed size exclusion chromatography-multiangle light scattering (SEC-MALS) analysis is used to provide important a priori insights into the solution self-assembly of a well-defined and symmetric tetrablock copolymer with two acrylic acid (AA) outer blocks, two polystyrene (PS) inner blocks, and a trithiocarbonate (TTC) central group, prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. SEC-MALS experiments show that the copolymer forms aggregates in both tetrahydrofuran and N,N-dimethylformamide (DMF), even in the presence of different salts, but not in 1,4-dioxane (dioxane). Combined with MD simulations, these results indicate that the AA units are the main cause of aggregation through intermolecular hydrogen bonding, with additional stabilization by the central TTC. The block copolymer chains self-assemble in dioxane by adding cadmium acetate, originating flowerlike inverse micelles with a cadmium acrylate core and the TTC groups in the outer surface of the PS corona. The micelles were used as nanoreactors in the templated synthesis of a single cadmium selenide (CdSe) quantum dot (QD) in the core of each micelle, whereas the shell TTC groups can be converted into thiol functions for further use of these units in hierarchical nanostructures. Only in dioxane where simulations and SEC-MALS suggest an absence of copolymer aggregates prior to cadmium acetate addition do well-dispersed and highly luminescent CdSe QDs form by templated synthesis. These results provide valuable insights into the self-assembly of RAFT copolymers in different solvent systems as it relates to the preparation of emissive QDs with polymer-spaced thiol functionality for binding to gold nanostructures.

Controlling Structure and Function of Polymeric Drug Delivery Nanoparticles Using Microfluidics.

We demonstrate control of multiscale structure and drug delivery function for paclitaxel (PAX)-loaded polycaprolactone-block-poly(ethylene oxide) (PCL-b-PEO) polymeric nanoparticles (PNPs) via synthesis and flow-directed shear processing in a two-phase gas-liquid microfluidic reactor. This strategy takes a page from the engineering of commodity plastics, where processing rather than polymer chemistry provides an experimental handle on properties and function. PNPs formed from copolymers with three different PCL block lengths show sizes, morphologies, and loading efficiencies that depend on both the PCL block length and the microfluidic flow rate. By varying flow rate and comparing with a conventional bulk method of PNP preparation, we show that flow-variable shear processing provides control of PNP sizes and morphologies and enables slower PAX release times (up to 2 weeks) compared to bulk-prepared PNPs. Antiproliferative effects against cultured MCF-7 breast cancer cells were greatest for PNPs formed at an intermediate flow rate, corresponding to small and low-polydispersity spheres formed uniquely at this flow condition. Formation and flow-directed nanoscale shear processing in gas-liquid microfluidic reactors provides a manufacturing platform for drug delivery PNPs that could enable more effective and selective nanomedicines through multiscale structural control.

Synthesis, Self-Assembly, and Drug Delivery Characteristics of Poly(methyl caprolactone-co-caprolactone)-b-poly(ethylene oxide) Copolymers with Variable Compositions of Hydrophobic Blocks: Combining Chemistry and Microfluidic Processing for Polymeric Nanomedicines.

The synthesis, characterization, and self-assembly of a series of biocompatible poly(methyl caprolactone-co-caprolactone)-b-poly(ethylene oxide) amphiphilic block copolymers with variable MCL contents in the hydrophobic block are described. Self-assembly gives rise to polymeric nanoparticles (PNPs) with hydrophobic cores that decrease in crystallinity as the MCL content increases, and their morphologies and sizes show nonmonotonic trends with MCL content. PNPs loaded with the anticancer drug paclitaxel (PAX) give rise to in vitro PAX release rates and MCF-7 GI50 (50% growth inhibition concentration) values that decrease as the MCL content increases. We also show for selected copolymers that microfluidic manufacturing at a variable flow rate enables further control of PAX release rates and enhances MCF-7 antiproliferation potency. These results indicate that more effective and specific drug delivery PNPs are possible through tangential efforts combining polymer synthesis and microfluidic manufacturing.

Correction to "Thermally Crosslinked Functionalized Polydicyclopentadiene with a High T g and Tunable Surface Energy".

[This corrects the article DOI: 10.1021/acsomega.6b00193.].

Microfluidic Manufacturing of Polymeric Nanoparticles: Comparing Flow Control of Multiscale Structure in Single-Phase Staggered Herringbone and Two-Phase Reactors.

We compare the microfluidic manufacturing of polycaprolactone-block-poly(ethylene oxide) (PCL-b-PEO) nanoparticles (NPs) in a single-phase staggered herringbone (SHB) mixer and in a two-phase gas-liquid segmented mixer. NPs generated from two different copolymer compositions in both reactors and at three different flow rates, along with NPs generated using a conventional bulk method, are compared with respect to morphologies, dimensions, and internal crystallinities. Our work, the first direct comparison between alternate microfluidic NP synthesis methods, shows three key findings: (i) NP morphologies and dimensions produced in the bulk are different from those produced in a microfluidic mixer, whereas NP crystallinities produced in the bulk and in the SHB mixer are similar; (ii) NP morphologies, dimensions, and crystallinities produced in the single-phase SHB and two-phase mixers at the lowest flow rate are similar; and (iii) NP morphologies, dimensions, and crystallinities change with flow rate in the two-phase mixer but not in the single-phase SHB mixer. These findings provide new insights into the relative roles of mixing and shear in the formation and flow-directed processing of polymeric NPs in microfluidics, informing future reactor designs for manufacturing NPs of low polydispersity and controlled multiscale structure and function.

Microfluidic synthesis of dye-loaded polycaprolactone-block-poly(ethylene oxide) nanoparticles: Insights into flow-directed loading and in vitro release for drug delivery.

Using the fluorescent probe dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) as a surrogate for hydrophobic drugs, we investigate the effects of water content and on-chip flow rate on the multiscale structure, loading and release properties of DiI-loaded poly(ε-caprolactone)-block-poly(ethylene oxide) (PCL-b-PEO) nanoparticles produced in a gas-liquid segmented microfluidic device. We find a linear increase in PCL crystallinity within the nanoparticle cores with increasing flow rate, while mean nanoparticle sizes first decrease and then increase with flow rate coincident with the disappearance and reappearance of long filament nanoparticles. Loading efficiencies at the lower water content (cwc+10wt%) are generally higher (up to 94%) compared to loading efficiencies (up to 53%) at the higher water content (cwc+75wt%). In vitro release times range between ∼2 and 4days for nanoparticles produced at cwc+10wt% and >15days for nanoparticles produced at cwc+75wt%. At the lower water content, slower release of DiI is found for nanoparticles produced at higher flow rate, while at high water content, release times first decrease and then increase with flow rate. Finally, we investigate the effects of the chemical and physical characteristics of the release medium on the kinetics of in vitro DiI release and nanoparticle degradation. This work demonstrates the general utility of dye-loaded nanoparticles as model systems for screening chemical and flow conditions for producing drug delivery formulations within microfluidic devices.

Thermally Crosslinked Functionalized Polydicyclopentadiene with a High T g and Tunable Surface Energy.

Polydicyclopentadiene (PDCPD) is a tough, heavily crosslinked thermoset polymer that has high heat, chemical, and impact resistance coupled with a low density. Current limitations to the broader industrial application of PDCPD include its low surface energy and lack of chemical tunability. Here, we report the first example of a polymer derived from a carboxyl-functionalized dicyclopentadiene monomer and its subsequent thermal crosslinking. The resulting material has the highest glass-transition temperature reported for a polydicyclopentadiene and allows for the facile manipulation of the surface chemistry through alteration of the embedded functional group. We also report the first observation by differential scanning calorimetry of the crosslinking step as a discreet thermal event.

Multiscale Control of Hierarchical Structure in Crystalline Block Copolymer Nanoparticles Using Microfluidics.

Hierarchical semicrystalline block copolymer nanoparticles are produced in a segmented gas-liquid microfluidic reactor with top-down control of multiscale structural features, including nanoparticle morphologies, sizes, and internal crystallinities. Control of multiscale structure on disparate length scales by a single control variable (flow rate) enables tailoring of drug delivery nanoparticle function including release rates.

Simultaneous patterning of two different types of nanoparticles into alternating domains of a striped array of a polymer blend in a single spin-casting step.

A fast and convenient method is developed for simultaneously patterning inorganic nanoparticles with different optical, electronic or magnetic functionality to specific surface regions, by spin-casting onto microcontact printed substrates blend solutions in which the two nanoparticle types are functionalized with surface polymer brush layers of different surface energies. The process is based on phase separation of different nanoparticles based on their immiscible brush layers during spin-casting, with the underlying surface energy heterogeneity of the patterned substrate directing the different NP types to domains of different surface energies. Here, we specifically demonstrate the simultaneous localization of cadmium sulfide quantum dots (CdS QDs), addressed with a surface layer of polystyrene (PS), and silver nanoparticles (Ag NPs), addressed with a surface layer of poly(methyl methacrylate) (PMMA), onto the non-polar and polar surface domains, respectively, of hydrophilic glass patterned with hydrophobic octadecyltrichlorosilane (OTS) stripe arrays with micron-scale periodicities. In order to prevent gelation of solvent-swollen polymer-brush coated NPs during spin casting, which effects strong kinetic constraints on phase separation and localization, PS, PMMA or PS/PMMA homopolymer blends of sufficiently high Mw were added to the NP blends to increase the free volume between approaching NPs. The process parameters were fine-tuned to obtain control over defects in the obtained patterns.