Immune Complexes Mimicking Synthetic Vaccine Nanoparticles for Enhanced Migration and Cross‐Presentation of Dendritic Cells

The well‐designed activation of dendritic cells (DCs) by enhancing the delivery of antigens and immunostimulatory adjuvants into DCs is a key strategy for efficient cancer immunotherapy. Antigen‐antibody immune complexes (ICs) are known to directly bind to and cross‐link Fc‐gamma receptors (FcγRs) on DCs, which induce enhanced migration of DCs to draining lymph nodes through the up‐regulation of the chemokine receptor CCR7 and cross‐presentation inducing cytotoxic T lymphocyte (CTL) response against tumor antigen. In this study, ICs mimicking synthetic vaccine nanoparticles (NPs) are designed and synthesized by the coating of poly (lactic‐co‐glycolic acid) (PLGA) NPs containing adjuvant (CpG oligodeoxynuleotides (ODNs) as toll‐like receptor 9 ligands) with ovalbumin (OVA) proteins (as model antigens) and by the formation of OVA–OVA antibody ICs. Through the combination of FcγRs‐mediated efficient antigen uptake and CpG ODNs‐based immunostimulation, the secretion of TNF‐α (12.3‐fold), IL‐6 (7.29‐fold), and IL‐12 (11‐fold), homing ability to lymph nodes (7.5‐fold), and cross‐presentation (83.8‐fold IL‐2 secretion) are dramatically increased in DCs treated with PLGA(IC/CpG) NPs. Furthermore, mice vaccinated with DCs treated with PLGA(IC/CpG) NPs induced significant tumor (EG7‐OVA) growth inhibition as well as prolonged survival through CTL‐mediated enhanced cytotoxicity, antigen‐specific responses, and IFN‐γ secretion.     

Tissue Engineering: Scaffold‐Mediated 2D Cellular Orientations for Construction of Three Dimensionally Engineered Tissues Composed of Oriented Cells and Extracellular Matrices (Adv. Funct. Mater. 7/2009)

Various hydrogels, such as poly(γ‐glutamic acid) (γ‐PGA), gelatin (GT), alginic acid (Alg), and agarose (Aga), with 3D interconnected and oriented fibrous pores (OP gels) are prepared for 3D polymeric cellular scaffolds by using silica fiber cloth (SC) as template. After the preparation of these hydrogels with the SC templates, the latter are subsequently removed by washing with hydrofluoric acid solution. Scanning electron microscopy (SEM) clearly shows OP structures in the hydrogels. These various types of OP gels are successfully prepared in this way, independently of the crosslinking mechanism, such as chemical (γ‐PGA or GT), coordinate‐bonded (Alg), or hydrogen‐bonded (Aga) crosslinks. SEM, confocal laser scanning microscopy, and histological evaluations clearly demonstrate that mouse L929 fibroblast cells adhere to and extend along these OP structures on/in γ‐PGA hydrogels during 3D cell culture. The L929 cells that adhere on/in the oriented hydrogel are viable and proliferative. Furthermore, 3D engineered tissues, composed of the oriented cells and extracellular matrices (ECM) produced by the cells, are constructed in vitro by subsequent decomposition of the hydrogel with cysteine after 14 days of cell culture. This novel technology to fabricate 3D‐engineered tissues, consisting of oriented cells and ECM, will be useful for tissue engineering.     

Phenylboronic Acid‐Decorated Chondroitin Sulfate A‐Based Theranostic Nanoparticles for Enhanced Tumor Targeting and Penetration

Phenylboronic acid‐functionalized chondroitin sulfate A (CSA)–deoxycholic‐acid (DOCA)‐based nanoparticles (NPs) are prepared for tumor targeting and penetration. (3‐Aminomethylphenyl)boronic acid (AMPB) is conjugated to CSA–DOCA conjugate via amide bond formation, and its successful synthesis is confirmed using proton nuclear magnetic resonance spectroscopy (¹H‐NMR). Doxorubicin (DOX)‐loaded CSA–DOCA–AMPB NPs with a mean diameter of ≈200 nm, a narrow size distribution, negative zeta potential, and spherical morphology are prepared. DOX release from NPs is enhanced at acidic pH compared to physiological pH. CSA–DOCA–AMPB NPs exhibit improved cellular uptake in A549 (human lung adenocarcinoma) cells and penetration into A549 multicellular spheroids compared to CSA–DOCA NPs as evidenced by confocal laser scanning microscopy and flow cytometry. In vivo tumor targeting and penetrating by CSA–DOCA–AMPB NPs, based on both CSA–CD44 receptor and boronic acid–sialic acid interactions, is revealed using near‐infrared fluorescence (NIRF) imaging. Penetration of NPs to the core of the tumor mass is observed in an A549 tumor xenografted mouse model and verified by three‐dimensional NIRF imaging. Multiple intravenous injections of DOX‐loaded CSA–DOCA–AMPB NPs efficiently inhibit the growth of A549 tumor in the xenografted mouse model and increase apoptosis. These boronic acid‐rich NPs are promising candidates for cancer therapy and imaging.     

Primary Cell Adhesion on RGD‐Functionalized and Covalently Crosslinked Thin Polyelectrolyte Multilayer Films

Polyelectrolyte multilayers (PEMs) are now widely used for biomedical applications. In this work, we investigated the primary osteoblast adhesion properties of PEMs of poly(L ‐lysine) (PLL), poly(L ‐glutamic acid) (PGA), poly(alginic acid) (Palg), and poly(galacturonic acid) (Pgal). In order to compensate for the poor adhesion of the as‐synthesized films, two kinds of film modifications were achieved: a purely physical modification by film crosslinking, and a chemical modification by grafting a arginine–glycine–aspartic acid (RGD) peptide to PGA. Crosslinking was performed using a water‐soluble carbodiimide in combination with N‐hydroxysulfosuccinimide (sulfo‐NHS) to induce amide formation. This reaction was followed by Fourier‐transform IR spectroscopy. For film functionalization, a 15‐amino‐acid peptide was grafted to PGA and deposited as the top layer of the film. PLL/PGA, PLL/Palg, and PLL/Pgal films were crosslinked or functionalized. The films were tested for both short‐term adhesion properties and long‐term proliferation of primary osteoblasts. Whereas the effect of film crosslinking on short‐term adhesion was moderate, it was much more important for the RGD‐functionalized films. On the other hand, the long‐term proliferation was the same or even higher for the crosslinked films as compared with the functionalized films. This effect was particularly enhanced for the PLL/Palg and PLL/Pgal films. Finally, we functionalized PLL/PGA that had been crosslinked prior to PGA‐RGD deposition. These architectures exhibited even higher short‐term adhesion and proliferation. These results clearly show the important role of the physical properties of the films, besides their chemical properties, for the modulation of primary cell‐adhesion behavior.     

Polyhedral Oligomeric Silsesquioxanes‐Containing Conjugated Polymer Loaded PLGA Nanoparticles with Trastuzumab (Herceptin) Functionalization for HER2‐Positive Cancer Cell Detection

The synthesis of polyhedral oligomeric silsesquioxanes (POSS)‐containing conjugated polymer (CP) and the polymer loaded poly(lactic‐co‐glycolic‐acid) (PLGA) nanoparticles (NPs) with surface antibody functionalization for human epidermal growth factor receptor 2 (HER2)‐positive cancer cell detection are reported. Due to the steric hindrance of POSS, NPs prepared from POSS‐containing CP show improved photoluminescence quantum yield as compared to that for the corresponding linear CP encapsulated NPs. In addition, the amount of ‐NH₂ groups on NP surface is well‐controlled by changing the molar ratio of poly(lactic‐co‐glycolic‐acid)‐b‐poly(ethylene glycol) (PLGA‐b‐PEG‐NH₂) to PLGA‐OCH₃ during NP formulation. Further conjugation of the NH₂‐functionalized CP NPs with trastuzumab (Herceptin) yields NPs with fine‐tuned protein density. These NPs are able to discriminate SKBR‐3 breast cancer cells from MCF‐7 breast cancer cells and NIH/3T3 fibroblast cells both on substrate and in suspension by taking advantage of the specific binding affinity between trastuzumab and HER2 overexpressed in SKBR‐3 breast cancer cell membrane. The high quantum yield and fine‐tuned surface specific protein functionalization make the POSS‐containing CP loaded NPs a good candidate for targeted biological imaging and detection.     

Cancer Detection: Polyhedral Oligomeric Silsesquioxanes‐Containing Conjugated Polymer Loaded PLGA Nanoparticles with Trastuzumab (Herceptin) Functionalization for HER2‐Positive Cancer Cell Detection (Adv. Funct. Mater. 2/2011)

The synthesis of polyhedral oligomeric silsesquioxanes (POSS)‐containing conjugated polymer (CP) and the polymer loaded poly(lactic‐co‐glycolic‐acid) (PLGA) nanoparticles (NPs) with surface antibody functionalization for human epidermal growth factor receptor 2 (HER2)‐positive cancer cell detection are reported. Due to the steric hindrance of POSS, NPs prepared from POSS‐containing CP show improved photoluminescence quantum yield as compared to that for the corresponding linear CP encapsulated NPs. In addition, the amount of ‐NH₂ groups on NP surface is well‐controlled by changing the molar ratio of poly(lactic‐co‐glycolic‐acid)‐b‐poly(ethylene glycol) (PLGA‐b‐PEG‐NH₂) to PLGA‐OCH₃ during NP formulation. Further conjugation of the NH₂‐functionalized CP NPs with trastuzumab (Herceptin) yields NPs with fine‐tuned protein density. These NPs are able to discriminate SKBR‐3 breast cancer cells from MCF‐7 breast cancer cells and NIH/3T3 fibroblast cells both on substrate and in suspension by taking advantage of the specific binding affinity between trastuzumab and HER2 overexpressed in SKBR‐3 breast cancer cell membrane. The high quantum yield and fine‐tuned surface specific protein functionalization make the POSS‐containing CP loaded NPs a good candidate for targeted biological imaging and detection.     

Noninvasive Transdermal Vaccination Using Hyaluronan Nanocarriers and Laser Adjuvant

Vaccines are commonly administered by injection using needles. Although transdermal microneedles are less invasive promising alternatives, needle‐free topical vaccination without involving physical damage to the natural skin barrier is still sought after as it can further reduce needle‐induced anxiety and is simple to administer. However, this long‐standing goal has been elusive since the intact skin is impermeable to most macromolecules. Here, we show an efficient, noninvasive transdermal vaccination by employing two key innovations: the use of hyaluronan (HA) as vaccine carriers and non‐ablative laser adjuvants. Conjugates of a model vaccine ovalbumin (OVA) and HA—HA–OVA conjugates—induced more effective maturation of dendritic cells in vitro, compared to OVA. Following topical administration in the skin, HA–OVA conjugates penetrated into the epidermis and dermis in murine and porcine skins, as revealed by intravital microscopy and fluorescence assay. Topical administration of HA‐OVA conjugates significantly elevated both humoral and mucosal antibodies, with peak levels at four weeks. An OVA challenge at week eight elicited strong immune‐recall responses. With pretreatment of the skin using non‐ablative fractional laser beams as adjuvant, strong immunization was achieved with much reduced doses of HA–OVA (1 mg kg^–1 OVA). Our results demonstrate the potential of the noninvasive patch‐type transdermal vaccination platform.     

Triphenylphosphonium‐Conjugated Poly(ε‐caprolactone)‐Based Self‐Assembled Nanostructures as Nanosized Drugs and Drug Delivery Carriers for Mitochondria‐Targeting Synergistic Anticancer Drug Delivery

For mitochondria‐targeting delivery, a coupling reaction between poly(ε‐caprolactone) diol (PCL diol) and 4‐carboxybutyltriphenylphosphonium (4‐carboxybutyl TPP) results in the synthesis of amphiphilic TPP‐PCL‐TPP (TPCL) polymers with a bola‐like structure. In aqueous environments, the TPCL polymer self‐assembled via cosolvent dispersion and film hydration, resulting in the formation of cationic nanoparticles (NPs) less than 50 nm in size with zeta‐potentials of approximately 40 mV. Interestingly, different preparation methods for TPCL NPs result in various morphologies such as nanovesicles, nanofibers, and nanosheets. In vitro cytotoxicity results with TPCL NPs indicate IC₅₀ values of approximately 10–60 μg mL^?1, suggesting their potential as anticancer nanodrugs. TPCL NPs can be loaded both with hydrophobic doxorubicin (Dox) and its hydrophilic salt form (Dox·HCl), and their drug loading contents are approximately 2–10 wt% depending on the loading method and the hydrophilicity/hydrophobicity of the drugs. Although Dox·HCl exhibits more cellular and nuclear uptake, resulting in greater antitumor effects than Dox, most drug‐loaded TPCL NPs exhibit higher mitochondrial uptake and approximately 2–7‐fold higher mitochondria‐to‐nucleus preference than free drugs, resulting in superior (approximately 7.5–18‐fold) tumor‐killing activity for most drug‐loaded TPCL NPs compared with free drugs. In conclusion, TPCL‐based nanoparticles have potential both as antitumor nanodrugs themselves and as nanocarriers for chemical therapeutics.     

Encapsulation of Nanoparticles Using Nitrilotriacetic Acid End‐Functionalized Polystyrenes and Their Application for the Separation of Proteins

The use of nitrilotriacetic acid end‐functionalized polystyrenes (NTA‐PS) as a multifunctional nanocarrier for the aqueous dispersion of CdSe, γ‐Fe₂O₃ and gold nanoparticles (NPs) is described. When the amphiphilic end‐ functionalized polystyrenes and NPs are dissolved together in tetrahydrofuran, the addition of water causes the spontaneous formation of micellar aggregates, resulting in the successful encapsulation and aqueous dispersion of NPs. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy, and vibrating sample magnetometer (VSM) are used to characterize the structure and properties of the NPs‐containing micellar aggregates (nanocarrier). After complexation of Ni²⁺ with NTA on the surface of the nanocarrier containing γ‐Fe₂O₃, specific binding between Ni‐NTA complex and histidine‐tagged (His‐tagged) proteins enables selective separation of His‐tagged proteins using a magnet.     

Self‐Assembled Robust Dipeptide Nanotubes and Fabrication of Dipeptide‐Capped Gold Nanoparticles on the Surface of these Nanotubes

Three water‐soluble dipeptides containing N‐terminally located β‐alanine residue and C‐terminally located α‐amino acid residues (β‐Ala‐L ‐Xaa, Xaa = Val/Ile/Phe) form robust crystalline nanotubes. These dipeptide nanotubes contain a common motif, a hybrid of β,α‐amino acids, which are stable against heat up to 80 °C, a wide range of pH (2–10), and proteolytic degradation. These robust crystalline dipeptide nanotubes are used as a template for fabricating dipeptide‐capped gold nanoparticles on their outer surfaces. This is an easy way to develop nanotube/nanoparticle hybrid materials under mild conditions.     

Understanding the Host–Guest Interaction Between Responsive Core‐Crosslinked Hybrid Nanoparticles of Hyperbranched Poly(ether amine) and Dyes: The Selective Adsorption and Smart Separation of Dyes in Water

The host–guest interaction between polymer nanoparticles and guest molecules plays a key role in fields such as controlled drug delivery, separation, and nanosensors. To understand this host–guest interaction, a series of hybrid polymer nanoparticles (SiO_1.5‐hPEA NPs) are designed and prepared based on hyperbranched poly(ether amine) (hPEA) with the different hydrophobicity and functional groups. Their adsorption behavior to twelve hydrophilic dyes in aqueous solution is studied. The core‐crosslinked hybrid nanoparticles (SiO_1.5‐hPEA NPs) are prepared by direct dispersion of hPEA containing trimethoxysilyl moieties (TMS‐hPEA) in aqueous solution, which exhibit sharp multiresponse to temperature, pH, and ionic strength in aqueous solution. The effect of molecular structure of TMS‐hPEA on the host–guest interaction between SiO_1.5‐hPEA NPs and hydrophilic dyes is investigated in detail. The obtained SiO_1.5‐hPEA NPs interact selectively with different hydrophilic dyes in aqueous solution. The distribution coefficient (K) for partitioning of dyes between SiO_1.5‐hPEA NPs and water is proposed to define the strength of the host‐guest interaction between the nanoparticles and dyes. K increases with the increasing hydrophobicity of the hPEA backbone regardless of their charge states of SiO_1.5‐hPEA NPs and dyes. A methodology is demonstrated for the smart separation of a mixture of dyes in water using SiO_1.5‐hPEA NPs.     

Printed,Flexible, Organic Nano‐Floating‐Gate Memory: Effects of Metal Nanoparticles and Blocking Dielectrics on Memory Characteristics

The effects of using a blocking dielectric layer and metal nanoparticles (NPs) as charge‐trapping sites on the characteristics of organic nano‐floating‐gate memory (NFGM) devices are investigated. High‐performance NFGM devices are fabricated using the n‐type polymer semiconductor, poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)} (P(NDI2OD‐T2)), and various metal NPs. These NPs are embedded within bilayers of various polymer dielectrics (polystyrene (PS)/poly(4‐vinyl phenol) (PVP) and PS/poly(methyl methacrylate) (PMMA)). The P(NDI2OD‐T2) organic field‐effect transistor (OFET)‐based NFGM devices exhibit high electron mobilities (0.4–0.5 cm² V^?1 s^?1) and reliable non‐volatile memory characteristics, which include a wide memory window (≈52 V), a high on/off‐current ratio (I_on/I_off ≈ 10⁵), and a long extrapolated retention time (>10⁷ s), depending on the choice of the blocking dielectric (PVP or PMMA) and the metal (Au, Ag, Cu, or Al) NPs. The best memory characteristics are achieved in the ones fabricated using PMMA and Au or Ag NPs. The NFGM devices with PMMA and spatially well‐distributed Cu NPs show quasi‐permanent retention characteristics. An inkjet‐printed flexible P(NDI2OD‐T2) 256‐bit transistor memory array (16 × 16 transistors) with Au‐NPs on a polyethylene naphthalate substrate is also fabricated. These memory devices in array exhibit a high I_on/I_off (≈10^{4 ± 0.85}), wide memory window (≈43.5 V ± 8.3 V), and a high degree of reliability.     

Generic Strategy of Preparing Fluorescent Conjugated‐Polymer‐Loaded Poly(DL‐lactide‐co‐Glycolide) Nanoparticles for Targeted Cell Imaging

A general strategy for the preparation of highly fluorescent poly(DL‐lactide‐co‐glycolide) (PLGA) nanoparticles (NPs) loaded with conjugated polymers (CPs) is reported. The process involves encapsulation of organic‐soluble CPs with PLGA using a modified solvent extraction/evaporation technique. The obtained NPs are stable in aqueous media with biocompatible and functionalizable surfaces. In addition, fluorescent properties of the CP‐loaded PLGA NPs (CPL NPs) could be fine‐tuned by loading different types of CPs into the PLGA matrix. Four types of CPL NPs are prepared with a volume‐average hydrodynamic diameter ranging from 243 to 272 nm. The application of CPL NPs for bio‐imaging is demonstrated through incubation with MCF‐7 breast cancer cells. Confocal laser scanning microscopy studies reveal that the CPL NPs are internalized in cytoplasm around the nuclei with intense fluorescence. After conjugation with folic acid, cellular uptake of the surface‐functionalized CPL NPs is greatly enhanced via receptor‐mediated endocytosis by MCF‐7 breast cancer cells, as compared to that for NIH/3T3 fibroblast cells, which indicates a selective targeting effect of the folate‐functionalized CPL NPs in cellular imaging. The merits of CPL NPs, such as low cytotoxicity, high fluorescence, good photostability, and feasible surface functionalization, will inspire extensive study of CPL NPs as a new generation of probes for specific biological imaging and detection.     

Extracellular Microreactor for the Depletion of Phenylalanine Toward Phenylketonuria Treatment

Phenylketonuria (PKU) is a genetic enzyme defect affecting 1:10 000–20 000 newborn children every year. The amino acid phenylalanine (Phe) is not depleted but accumulates in tissues of several organs, which leads to severe medical conditions. A promising concept to restore the metabolism of the affected patients will be to orally administer the defective enzyme which will remove Phe in the intestine. Herein, capsosomes, a multicompartment carrier consisting of thousands of liposomes embedded within a polymeric carrier, are employed as encapsulation platform for this purpose. It is shown that the enzyme phenylalanine ammonia lyase can be entrapped within the liposomal compartments with preserved activity, demonstrated by the conversion of Phe into trans‐cinnamic acid (t‐ca). With the aim to mimic the dynamic environment in the intestine, the Phe conversion is performed in a microfluidic set up in the presence of human intestinal epithelial cells with applied intestinal flow and peristaltic motions. It is also shown that the microreactors are neither internalized by the cells nor exhibit inherent cytotoxicity while concurrently converting Phe into t‐ca. Taken together, the first active extracellular multicompartment microreactor is reported using the relevant enzymes and settings toward the treatment of the medical condition PKU.     

Facile Fabrication of Highly Dispersed Pd@Ag Core–Shell Nanoparticles Embedded in Spirulina platensis by Electroless Deposition and Their Catalytic Properties

Microorganisms are widely used as the biotemplates for producing micro/nanomaterials owing to their unique features, such as exquisite morphology, renewable, and environmentally friendly. However, mass intracellular synthesis of uniformly dispersed nanoparticles (NPs) inside microorganisms is still challenging, especially in a predictable and controllable manner. Here, a facile and efficiency strategy is proposed to controllably produce highly dispersed and surfactant‐free Pd@Ag core–shell NPs within the Spirulina platensis (Sp.) cells. In this approach, the Sp. cells' permeability is enhanced by the hydrochloric acid treatment first, which enables the Pd NPs penetrate the cell envelope and distribute uniformly inside the cells, and then they can work as the catalytic seeds for the following electroless silver deposition, resulting in the intracellular fabrication of Pd@Ag core–shell NPs with no agglomeration. The Pd@Ag NPs show excellent catalytic activity (turnover frequency is up to 2893 h^?1 for the 6.32 nm Pd@Ag NPs), good stability, and recyclability toward the 4‐nitrophenol reductions. The excellent properties are attributed to the asymmetrical core–shell structure, small size, and good dispersion of Pd@Ag NPs. Due to its facility, cost‐effectiveness, and versatility, this method can be expanded to other microorganisms, so it opens tremendous opportunities for various metallic nanoparticles intracellular synthesis as well as the practical application.     

Site‐Specific Placement of Au Nanoparticles on Chemical Nanopatterns Prepared by Molecular Transfer Printing Using Block‐Copolymer Films

Inexpensive, large area patterning of ex‐situ synthesized metallic nanoparticles (NPs) at the nanoscale may enable many technologies including plasmonics, nanowire growth, and catalysis. Here, site‐specific localization of Au NPs onto nanoscale chemical patterns of polymer brushes is investigated. In this approach, patterns of hydroxyl‐terminated poly(styrene) brushes are transferred from poly(styrene‐block‐methyl methacrylate) (PS‐b‐PMMA) block copolymer films onto a replica substrate via molecular transfer printing, and the remaining areas are filled with hydroxyl‐terminated poly(2‐vinyl pyridine) (P2VP‐OH) brushes. Citrate‐stabilized Au NPs (13 nm) selectively bind to P2VP‐OH functionalized regions and the quality of the resulting assemblies depends on high chemical contrast in the patterned brushes. Minimization of the interpenetration of P2VP‐OH chains into PS brushes during processing is the key for achieving high chemical contrast. Large area hexagonal arrays of single Au NPs with a placement accuracy of 3.4 nm were obtained on patterns (～20 nm spots, ～40 nm pitch) derived from self‐assembled cylinder‐forming PS‐b‐PMMA films. Linear arrays of Au NPs were generated on patterns (40 nm lines, 80nm pitch) derived from lamellae‐forming PS‐b‐PMMA that had been directed to assemble on lithographically defined masters.     

Large AuAg Alloy Nanoparticles Synthesized in Organic Media Using a One‐Pot Reaction: Their Applications for High‐Performance Bulk Heterojunction Solar Cells

A one‐pot synthesis of large size and high quality AuAg alloy nanoparticles (NPs) with well controlled compositions via hot organic media is demonstrated. Amid the synthesis, complexation between trioctylphosphine (TOP) and metal precursors is found, which slows down the rate of nucleation and leads to the growth of large‐size AuAg nanoalloys. The wavelength and relative intensities of the resulting plasmon bands are readily fine‐tuned during the synthetic process using different Au/Ag precursors molar ratios. In the polymer solar cells, a key step in achieving high efficiency is the utilization of 1% Au₁₁Ag₈₉ alloy NPs embedded in the active layer to promote the power conversion efficiency (PCE) up to 4.73%, which outperforms the reference device based on the control standard device of poly(3‐hexylthiophene) (P3HT):phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM) under identical conditions. Corresponding increases in short‐circuit current density (J_sc), open‐circuit voltage (V_oc), fill factor (FF), and incident photon‐to‐current efficiency (IPCE) enable 31% PCE improvement due to the enhancement of the light‐trapping and the improvement of charge transport in the active layer. The findings advance the fundamental understanding and point to the superiority of Au₁₁Ag₈₉ nanoalloys as a promising metallic additive over Au, Ag, and Au₂₈Ag₇₂ alloy NPs to boost the solar cell performance.     

Conjugated Polymer Based Nanoparticles as Dual‐Modal Probes for Targeted In Vivo Fluorescence and Magnetic Resonance Imaging

A facile strategy is developed to synthesize dual‐modal fluorescent‐magnetic nanoparticles (NPs) with surface folic acid by co‐encapsulation of a far‐red/near‐infrared (FR/NIR)‐emissive conjugated polymer (PFVBT) and lipid‐coated iron oxides (IOs) into a mixture of poly(lactic‐co‐glycolic‐acid)‐poly(ethylene glycol)‐folate (PLGA‐PEG‐FOL) and PLGA. The obtained NPs exhibit superparamagnetic properties and high fluorescence, which indicates that the lipid coated on IOs is effective at separating the conjugated polymer from IOs to minimize fluorescence quenching. These NPs are spherical in shape with an average diameter of ≈180 nm in water, as determined by laser light scattering. In vitro studies reveal that these dual‐modal NPs can serve as an effective fluorescent probe to achieve targeted imaging of MCF‐7 breast cancer cells without obvious cytotoxicity. In vivo fluorescence and magnetic resonance imaging results suggest that the NPs are able to preferentially accumulate in tumor tissues to allow dual‐modal detection of tumors in a living body. This demonstrates the potential of conjugated polymer based dual‐modal nanoprobes for versatile in vitro and in vivo applications in future.     

Adenoviral Gene Delivery from Multilayered Polyelectrolyte Architectures

The alternate layer‐by‐layer (LBL) deposition of polycations and polyanions for the build up of multilayered polyelectrolyte films is an original approach that allows the preparation of tunable, biologically active surfaces. The resulting supramolecular nanoarchitectures can be functionalized with drugs, peptides, and proteins, or DNA molecules that are able to transfect cells in vitro. We monitor, for the first time, the embedding of a bioactive adenoviral (Ad) vector in multilayered polyelectrolyte films. Ad efficiently adsorbs on poly(L ‐lysine)–poly(L ‐glutamic acid) (PLL–PGA), PLL–HA (HA: hyaluronan), poly(allylamin hydrochloride)–poly(sodium‐4‐styrenesulfonate) (PAH–PSS), and CHI–HA (CHI: chitosan) films; it preserves its transduction capacity (which can reach 95 %) for a large number of cell types, and also allows vector uptake into receptor‐deficient cells, thus abrogating the restricted tropism of Ad.     

Enhancement of Phosphorescence by Surface‐Plasmon Resonances in Colloidal Metal Nanoparticles: The Role of Aggregates

The spectroscopic and near‐field scanning optical microscopy (NSOM) studies of phosphorescent films doped with colloidal gold nanoparticles (NPs) are presented. Films with a high concentration of 2,3,7,8,12,13,17,18‐octaethyl‐21H,23H‐porphine platinum(II ) dispersed in a neutral polymer poly[(methyl methacrylate)‐co‐(ethyl acrylate)] demonstrate a twofold increase of the phosphorescence quantum yield after the addition of aggregated NPs. In materials doped with unaggregated particles, a decrease of the emission yield is observed. Theoretical modeling of the phosphorescence transients suggests a minimization of the triplet–triplet quenching owing to the presence of fast processes that decrease the concentration of chromophores in the excited state and may be both of radiative and non‐radiative origin. NSOM examination of the films reveals increased light emission around large NP clusters. This observation demonstrates significant enhancement of the spontaneous emission rates by the large aggregates, although unaggregated NPs introduce mostly phosphorescence quenching sites.