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The blood-brain barrier (BBB) is the major clinical obstacle in the chemotherapeutic management of brain glioma. Here we synthesized a pH-sensitive dual-targeting doxorubicin (DOX) carrier to compromise tumor endothelial cells, enhance BBB transportation, and improve drug accumulation in glioma cells. The drug delivery system was constructed with polydopamine (PDA)-coated mesoporous silica nanoparticles (NPs, MSNs) and the PDA coating was functionalized with Asn-Gly-Arg (NGR), a ligand with specific affinity for cluster of differentiation 13 (CD13). MSN-DOX-PDA-NGR showed a higher intracellular accumulation in primary brain capillary endothelial cells (BCECs) and C6 cells and greater BBB permeability than the non-targeting NPs (MSN-DOX-PDA) did in vitro. Ex vivo and in vivo tests showed that MSN-DOX-PDA-NGR had a higher accumulation in intracranial tumorous tissue than the undecorated NPs did. Furthermore, the antiangiogenesis and antitumor efficacy of MSN-DOX-PDA-NGR were stronger than that of MSN-DOX-PDA. Therefore, these results indicate that the dual-targeting vehicles are potentially useful in brain glioma therapy.

With the aim to develop a facile strategy to prepare functional drug carriers to overcome multidrug resistance (MDR), we prepared heparin/protamine/calcium carbonate (HP/PS/CaCO3) hybrid nanovesicles with enhanced cell internalization, good serum stability, and pH sensitivity for drug delivery. All the functional components including protamine to improve the cell uptake, heparin to enhance the stability, and CaCO3 to improve drug loading and endow the system with pH sensitivity were introduced to the nanovesicles by self-assembly in an aqueous medium. An antitumor drug (doxorubicin, DOX) and a drug resistance inhibitor (tariquidar, TQR) were coloaded in the nanovesicles during self-assembly preparation of the nanovesicles. The drug loaded nanovesicles, which had a mean size less than 200 nm, exhibited a pH-sensitive drug release behavior. In vitro study was carried out in both nonresistant cells (HeLa and MCF-7) and drug-resistant cancer cells (MCF-7/ADR). Because of the enhanced intracellular and nuclear drug accumulation through effective inhibition of the P-gp efflux transporter, DOX/TQR coloaded nanovesicles showed significantly improved tumor cell inhibitory efficiency, especially for drug-resistant cells. These results suggest the self-assembled nanovesicles have promising applications in multidrug delivery to overcome drug resistance in tumor treatments.

We simultaneously employed grazing incidence small-angle and wide-angle X-ray scattering (GISAXS and GIWAXS) techniques to quantitatively study the structural evolution and kinetic behavior of poly(3-hexylthiophene) (P3HT) crystallization, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) aggregation and amorphous P3HT/PCBM domains from a bulk heterojunction (BHJ) to a thermally unstable structure. The independent phase separation regimes on the nanoscale (∼10 nm), mesoscale (∼100 nm) and macroscale (∼μm) are revealed for the first time. Bis-PCBM molecules as inhibitors incorporated into the P3HT/PCBM blend films were adopted as a case study of a control strategy for improving the thermal stability of P3HT/PCBM solar cell. The detailed information on the formation, growth, transformation and mutual interaction between different phases during the hierarchical structural evolution of P3HT/PCBM:xbis-PCBM (x = 8-100%) blend films are presented herein. This systematic study proposes the mechanisms of thermal instability for a polymer/fullerene-based solar cell. We demonstrate a new fundamental concept that the structural evolution and thermal stability of mesoscale amorphous P3HT/PCBM domains during heating are the origin of controlling thermal instability rather than those of nanoscale thermally-stable BHJ structures. It leads to a low-cost and easy-fabrication control strategy for effectively tailoring the hierarchical morphology against thermal instability from molecular to macro scales. The optimum treatment achieving high thermal stability, control of mesoscale domains, can be effectively designed. It is independent of the original BHJ nanostructure design of a polymer/fullerene-based solar cell with high performance. It advances the general knowledge on the thermal instability directly arising from the nanoscale structure.

In this study, with the aim of designing an ideal anticancer drug carrier, we synthesized novel amphiphilic graft copolymers, P(Glu-alt-PEG)-graft-PCLA, based on poly(ethylene glycol) (PEG) segments and glutamic acid (Glu) units as the hydrophilic main chain, and poly(ɛ-caprolactone-co-lactide) (PCLA) as hydrophobic branches. The chemical structure of the copolymers was characterized by (1)H MNR and FT-IR. The self-assembly of the copolymers to form micelles was studied by TEM, DLS and fluorescence spectroscopy. In vitro doxorubicin controlled release studies demonstrated that these graft copolymer micelles had high drug loading capacity and good controlled released properties, demonstrating their potential as a novel anticancer drug carrier. The drug loaded graft copolymer micelles exhibited efficient inhibition of HeLa cells in in vitro studies., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Nanoparticulate drug-delivery systems have attained much importance because of their injectable property, the possibility to achieve passive targeting and active targeting, and unique advantages to realize stimuli tailored delivery. Molecular self-assembly is a powerful method for fabricating polymer-based nanoparticles, which involves various driving forces, such as hydrophobic interactions, electrostatic interactions, stereocomplexation, host/guest interactions and hydrogen bonding. By fine tuning one or many types of these interactions, self-assemblies with a wide range of structures and functions could be fabricated. In this article, recent developments in different self-assembly strategies for the preparation of polymer-based nanoparticulate delivery systems are discussed., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hyperbranched amphiphilic polymer PG6-PLA-PEG was synthesized through grafting hydrophobic poly(D,L-lactide) (PLA) segments and hydrophilic poly(ethylene glycol) (PEG) blocks to hydrophilic hyperbranched polyglycerol core (PG6), subsequently. To achieve cell targeting property, folic acid (FA) was further incorporated to the hyperbranched polymer to obtain PG6-PLA-PEG-FA. The polymers were characterized by (1)H NMR, UV-vis spectroscopy and combined size-exclusion chromatography and multiangle laser light scattering (SEC-MALLS) analysis. Due to the amphiphilicity, PG6-PLA-PEG and PG6-PLA-PEG-FA could self-assemble to form nanoparticles in aqueous solutions. Antineoplastic drug, paclitaxel (PTX), was encapsulated into the nanoparticles. The nanoparticles were observed by transmission electron microscopy (TEM). The targeting property of PG6-PLA-PEG-FA was evaluated in vitro. The results showed that the PTX loaded PG6-PLA-PEG-FA nanoparticles exhibited enhanced inhibition on folate receptor positive tumor cells due to the folate mediated targeting., (Copyright 2010 Elsevier B.V. All rights reserved.)

Hyperbranched polymers, PG6-PEI25k and PG6-PEI800, were synthesized through grafting branched polyethylenimines (PEIs) with molecular weights of 25 kDa and 800 Da to a polyglycerol core (PG6), respectively. The structure of the polymers was characterized by 1H NMR and FTIR. Through agarose gel electrophoresis retardation assay, PG6-PEI25k and PG6-PEI800 were demonstrated to have capability for DNA binding. PG6-PEI/DNA complexes with different weight ratios were characterized by TEM and particle size analysis. The activity of PG6-PEIs to mediate transfection of reporter plasmids pEGFP-C1 and pGL3-Luc was evaluated on 293T and HeLa cell lines. PG6-PEI25k and PG6-PEI800 showed enhanced levels in transgene expression and decreased cytotoxicities as compared with PEI25k and PEI800, respectively. The results indicated potential applications of PG6-PEIs for efficient gene delivery., (Copyright (c) 2009 Elsevier B.V. All rights reserved.)

Purpose: To study the targeting and photodynamic therapy efficiency of porphyrin and galactosyl conjugated micelles based on amphiphilic copolymer galactosyl and mono-aminoporphyrin (APP) incoporated poly(2-aminoethyl methacrylate)-polycaprolactone (Gal-APP-PAEMA-PCL)., Methods: Poly(2-aminoethyl methacrylate)-polycaprolactone (PAEMA-PCL) was synthesized by the combination of ring opening polymerization and reversible addition-fragmentation chain transfer (RAFT) polymerization, and then Gal-APP-PAEMA-PCL was obtained after conjugation of lactobionic acid and 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (APP) to PAEMA-PCL. The chemical structures of the copolymers were characterized, and their biological properties were evaluated in human laryngeal carcinoma (HEp2) and human hepatocellular liver carcinoma (HepG2) cells., Results: Both APP-PAEMA-PCL and Gal-APP-PAEMA-PCL did not exhibit dark cytotoxicity to HEp2 cells and HepG2 cells. However, Gal-APP-PAEMA-PCL was taken up selectively by HepG2 cells and had the higher phototoxicity effect. Both polymers preferentially localized within cellular vesicles that correlated to the lysosomes., Conclusions: The results indicated that porphyrin and galactosyl conjugated polymer micelles exhibited higher targeting and photodynamic therapy efficacy in HepG2 cells than in HEp2 cells.

In this study, a KRGDKK (Lys-Arg-Gly-Asp-Lys-Lys) peptide with a RGD sequence is utilized as a functional group to synthesize a novel thermo-sensitive hydrogel. The KRGDKK peptide prepared by a solid phase synthesis approach is coupled to the ends of a poly[(epsilon-caprolactone)-co-lactide]-poly(ethylene glycol)-poly[(epsilon-caprolactone)-co-lactide] (PCLA-PEG-PCLA) triblock copolymer to obtain peptide-PCLA-PEG-PCLA-peptide. The self-assembly behavior of both PCLA-PEG-PCLA and peptide-PCLA-PEG-PCLA-peptide copolymers in aqueous solution is investigated, and hydrogels prepared from PCLA-PEG-PCLA and peptide-PCLA-PEG-PCLA-peptide are also prepared. An in vitro cell viability study demonstrated that the peptide-PCLA-PEG-PCLA-peptide hydrogels do not exhibit an apparent cytotoxicity, which suggests that the hydrogels have promising potential as injectable drug-delivery systems. Furthermore, compared with the PCLA-PEG-PCLA hydrogels, the peptide-PCLA-PEG-PCLA-peptide hydrogels display improved mechanical properties because of hydrogen bonding between the amino groups of KRGDKK. An in vitro drug release study showed that the peptide-PCLA-PEG-PCLA-peptide hydrogels exhibit outstanding controlled release properties and the release of the drug could be sustained for more than a month without initial burst.

Calcium-phosphate/deoxyribose nucleic acid (Ca-P/DNA) co-precipitates were deposited on or encapsulated in fast-degrading polymer films with surface erosion degradation mechanism to mediate cell transfection. The polymer, cholic acid functionalized star poly(DL-lactide), was synthesized through the ring-opening polymerization of DL-lactide initiated by cholic acid. The releases of DNA from the Ca-P/DNA co-precipitates deposited film and the Ca-P/DNA co-precipitates encapsulated film were determined and compared. The in vitro gene transfections of HEK293 cells, Hela cells, and NIH 3T3 cells showed that the expression of pGL3-Luc plasmid could be effectively mediated by the Ca-P/DNA co-precipitates deposited and encapsulated polymer films. In addition, the films did not exhibit any additional cytotoxicity to the cells during the transfections, indicating that the fast-degrading polymer films have great potential in localized gene delivery., ((c) 2009 Wiley Periodicals, Inc.)

Galactosylated and fluorescein isothiocyanate (FITC) labeled polycaprolactone-g-dextran (Gal-PCL-g-Dex-FITC) polymers were synthesized. The grafted polymers can self-assemble into stable micelles in aqueous medium and in serum. Transmission electron microscopy (TEM) images showed that the self-assembled micelles were regularly spherical in shape. Micelle size determined by size analysis was around 120 nm. The anti-inflammation drug prednisone acetate as a model drug was loaded in the polymeric micelles, and the in vitro drug release was investigated. The galactosylated micelles could be selectively recognized by HepG2 cells and subsequently accumulate in HepG2 cells. The in vivo study demonstrated the relative uptake of the micelles by liver is much higher than the other tissues, indicating that the galactosylated micelles have great potential as a liver targeting drug carrier.

Amphiphilic hyperbranched core-shell polymers with folate moieties as the targeting groups were synthesized and characterized. The core of the amphiphilic polymers was hyperbranched aliphatic polyester Boltorn H40. The inner part and the outer shell of the amphiphilic polymers were composed of hydrophobic poly(epsilon-caprolactone) segments and hydrophilic poly(ethylene glycol) (PEG) segments, respectively. To achieve tumor cell targeting property, folic acid was further incorporated to the surface of the amphiphilic polymers via a coupling reaction between the hydroxyl group of the PEG segment and the carboxyl group of folic acid. The polymers were characterized by (1)H NMR, (13)C NMR, and combined size-exclusion chromatography and multiangle laser light scattering analysis. The nanoparticles of the amphiphilic polymers prepared by dialysis method were characterized by transmission electron microscopy and particle size analysis. Two antineoplastic drugs, 5-fluorouracil and paclitaxel, were encapsulated into the nanoparticles. The drug release property and the targeting of the drug-loaded nanoparticles to different cells were evaluated in vitro. The results showed the drug-loaded nanoparticles exhibited enhanced cell inhibition because folate targeting increased the cytotoxicity of drug-loaded nanoparticles against folate receptor expressing tumor cells.

An effective strategy was developed and demonstrated to improve the properties of thermosensitive poly(N-isopropylacrylamide) (PNIPAAm) hydrogel by using diethyl ether as a precipitation agent during the polymerization/crosslinking. Results reveal that the modified PNIPAAm hydrogels have the heterogeneous network structures and decreased LCSTs in a comparison with the normal PNIPAAm hydrogel. The modified PNIPAAm hydrogels also exhibit significantly improved sensitive properties, including fast response and stable, rapid, large magnitude oscillatory shrinking-swelling upon temperature cycles around lower critical solution temperature. In addition, fish DNA, used as a model drug, is loaded into the modified PNIPAAm hydrogels, the controlled release behaviors of the drug loaded hydrogels at different temperatures (22 and 37 degrees C) are further examined.

In order to investigate the influence of the continuous alkylamide sequence having pH sensitive unit on the temperature sensitivity of poly(N-isopropylacrylamide) (PNIPAAm)-based hydrogel, a monomer, N-(2-(dimethylamino) ethyl)-methacrylamide (DMAEMA), having an ethylamide group as well as an aliphatic tertiary amino group, was designed and synthesized. Hydrogels based on NIPAAm and DMAEMA were prepared via free radical polymerization. The resulted P(NIPAAm-co-DMAEMA) hydrogels were characterized in terms of maximum swelling ratio, swelling kinetics, temperature response kinetics, and effect of pH. The data obtained show that the novel hydrogels have the strong desire to respond to external temperature and pH stimuli. Importantly, because the P(NIPAAm-co-DMAEMA) hydrogels have the continuous alkylamide sequence containing isopropylamide pendant groups from PNIPAAm and ethylamide pendant groups from PDMAEMA, the incorporation of DMAEMA moiety not only provides the pH sensitivity, but also maintains the thermal properties of P(NIPAAm-co-DMAEMA) hydrogels, even as the molar percentage of DMAEMA moiety reaches 14 mol%.

A series of biocompatible and stimuli-sensitive poly(N-isopropylacrylamide-co-propyl acrylic acid) (P(NIPAAm-co-PAAc)) nanogels were synthesized by emulsion polymerization. In addition, polyethyleneimine (PEI) was further grafted to modify the PNIPAAm-based nanogels. The P(NIPAAm-co-PAAc)-g-PEI nanogels exhibited good thermosensitivity as well as pH sensitivity. Transmission electron microscopy (TEM) showed that the P(NIPAAm-co-PAAc)-g-PEI and P(NIPAAm-co-PAAc) nanogels displayed well dispersed spherical morphology. The mean sizes of the nanogels measured by dynamic light scattering (DLS) were from 100 nm to 500 nm at different temperatures. The cytotoxicity study indicated P(NIPAAm-co-PAAc) nanogels exhibited a better biocompatibility than both PNIPAAm nanogel and P(NIPAAm-co-PAAc)-g-PEI nanogel although all the three kinds of nanogels did not exhibit apparent cytotoxicity. The drug-loaded nanogels, especially the PEI-grafted nanogels, showed temperature-trigged controlled release behaviors, indicating the potential applications as an intelligent drug delivery system.

Biodegradable amphiphilic graft copolymers with different compositions were synthesized by grafting poly(L-lactide) (PLLA) sequences onto a water-soluble poly-alpha,beta-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA) backbone. The critical micelle concentration (CMC) of the graft polymers was determined by fluorescence probe technique. Using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, the graft polymers were proved to have low cytotoxicity. Based on the specific physicochemical property of the graft copolymers, submicron sized microsphere drug delivery systems were prepared by a very convenient "ultrasonic dispersion method", which did not involve toxic organic solvents. The drug-loaded microspheres had a regular spherical shape with a narrow size distribution. A hydrophobic drug, prednisone acetate, was encapsulated into polymeric microspheres and the in vitro drug release was studied.

Novel thermo-sensitive magnetomicelles that consist of a magnetic core, Fe(3)O(4)-oleic acid (Fe(3)O(4)-OA), and an amphiphilic surface layer of thermo-sensitive poly(oleic acid-co-N-isopropylacrylamide) P(OA-co-NIPAAm) co-polymer were prepared. Fe(3)O(4) magnetic cores functionalized with double bonds of oleic acid were prepared by suspension-oxidation reaction. Subsequently, by the co-polymerization of hydrophilic NIPAAm, hydrophobic OA and the Fe(3)O(4)-OA magnetic core, the thermo-sensitive amphiphilic polymers (P(OA-co-NIPAAm)) were grafted to obtain Fe(3)O(4)-OA-g-P(OA-co-NIPAAm) nanoparticles. The surface polymeric layer of Fe(3)O(4)-OA-g-P(OA-co-NIPAAm) nanoparticles would self-assemble in aqueous media to form a micellar structure attributed to the amphiphilic P(OA-co-NIPAAm) polymers. The model drug, prednisone acetate, was loaded in the magnetomicelles and in vitro release behavior of loaded drug in magnetomicelles was further investigated, which showed a thermo-sensitive release behavior due to the thermo-sensitive structural changes of the micellar surface layer.

Polyamidoamine (PAMAM) dendrimer/DNA complexes encapsulated in a water soluble polymer, poly-alpha,beta-[N-(2-hydroxyethyl)-l-aspartamide], were supported on a cholic acid functionalized star poly(DL-lactide) film with a fast degradation rate to mediate localized gene delivery. The in vitro gene transfections of two types of cells, HEK293 and NIH3T3, were investigated. The expressions of pGL3-Luc and pEGFP-C1 plasmids in HEK293 cells indicated that the star poly(DL-lactide) supported PHEA encapsulated PAMAM/DNA complexes could effectively mediate transfection, with transfection efficiencies which were comparable to that of solution-based transfections. Whereas the PAMAM/DNA complexes directly supported on the star poly(DL-lactide) film showed a much lower expression level for HEK293, which indicated the existence of PHEA played an important role in the efficient transfection. The solid support-based transfection for NIH3T3 cells exhibited higher expressions of pGL3-Luc compared with the solution-based transfection. Encapsulating PAMAM/DNA complexes in PHEA could further improve the gene expression in NIH3T3. During the cellular transfection, the degradation of the cholic acid functionalized star poly(DL-lactide) film could be obviously detected and the degradation did not show any unfavorable effects on the gene expression, which implied this solid support-based gene delivery device had great potential for localized transfection.

To investigate the temperature sensitive mechanism and develop temperature sensitive materials, a novel poly(N-isopropyl-3-butenamide) (PNIPBAm) hydrogel was designed and synthesized. The maximum swelling ratio, temperature dependence of swelling ratio and deswelling/reswelling kinetics of the resulted PNIPBAm hydrogel were characterized. The data obtained exhibited that the temperature sensitivity of the PNIPBAm hydrogel depended on the amount of crosslinker, i.e. the temperature sensitivity decreased with the increasing content of crosslinker. This novel temperature sensitive hydrogel would have the potential applications in bioengineering and biotechnology fields.

A series of biodegradable amphiphilic graft copolymers with poly-alpha,beta-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA) as the backbone and poly(2,2-dimethyltrimethylene carbonate) (PDTC) segments with different lengths as the grafted branches were synthesized and characterized. The in vitro degradation of the obtained PHEA-g-PDTC copolymers was studied. With particular branch lengths, PHEA-g-PDTC can form self-assembling micelles in an aqueous solution. Transmission electron microscopy (TEM) images demonstrated that the micelles were regularly spherical in shape. The particle size and distribution of the micelles were measured. Nanoparticle drug delivery systems were prepared by the direct dissolution method. The in vitro release behaviors of two drugs, prednisone acetate and tegafur, with different water solubilities were investigated.

Star oligo/poly(trimethylene carbonate)s with cholic acid moieties as cores were synthesized by ring-opening polymerization of trimethylene carbonate (TMC) initiated by cholic acid with hydroxyl groups. The molecular weights of the star oligomers/polymers were controlled by adjusting the feed ratio of the initiator cholic acid to the monomer TMC. The star oligo/poly(trimethylene carbonate)s were characterized by Fourier transform infrared spectroscopy (FT-IR), (1)H nuclear magnetic resonance spectroscopy ((1)H-NMR) and combined size-exclusion chromatography and multiangle laser light scattering (SEC-MALLS) analysis. The water contact angles of the star oligo/poly(trimethylene carbonate)s were measured. Using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, the star oligo/poly(trimethylene carbonate) was proved to have a low cytotoxicity. A microsphere drug-delivery system based on a star polymer was fabricated and its in vitro drug release property was studied.

A new amphiphilic Y-shaped copolymer, comprised of hydrophobic poly(undecylenic acid) (PUA) and hydrophilic poly(N-isopropylacrylamide) (PNIPAAm), was designed and synthesized. A cytotoxicity study revealed that P(UA-Y-NIPAAm) copolymers did not exhibit apparent inhibition impact on the proliferation of cells when the concentration of the copolymer was below 1000 mg/L. Characterization demonstrated that the P(UA-Y-NIPAAm) copolymer is thermosensitive with a lower critical solution temperature (LCST) of 31 degrees C. In water, the P(UA-Y-NIPAAm) copolymer would self-assemble into micelles with a critical micelle concentration (CMC) of 20 mg/L. Self-assembled P(UA-Y-NIPAAm) micelles exhibited a nanospherical morphology of 40 to approximately 80 nm in size. The controlled drug release behavior of the P(UA-Y-NIPAAm) micelles was further investigated, and self-assembled micelles exhibited improved properties in controlled drug release.

Biodegradable amphiphilic graft copolymers poly-alpha,beta-[N-(2-hydroxyethyl)-L-aspartamide]-g-poly(epsilon-caprolactone) (PHEA-g-PCL) with different branch lengths were synthesized through the ring-opening polymerization of epsilon-caprolactone initiated by the macroinitiator PHEA bearing hydroxyl groups. With use of the graft copolymers with different compositions, nanoparticle drug delivery systems with sizes smaller than 100 nm were prepared by a dialysis method, and microparticle drug delivery systems with sizes smaller than 5 microm were fabricated by a melting-emulsion method. The regularly spherical shapes of the drug-loaded nano- and microparticles were verified by transmission electron microscopy and scanning electron microscopy. In vitro drug release properties of nano- and microparticle drug delivery systems were investigated, with the emphasis on the effects of polymer composition, particle size, and drug-loading content on the release behaviors.

A biodegradable amphiphilic graft polymer was successfully synthesized by grafting hydrophobic poly(1,3-trimethylene carbonate) (PTMC) sequences onto a hydrophilic poly-alpha,beta-(N-(2-hydroxyethyl)-L-aspartamide) (PHEA) backbone. The graft polymer, PHEA-g-PTMC, was synthesized by ring-opening polymerization initiated by the macroinitiator PHEA bearing hydroxyl groups without adding any catalyst. The graft polymer was characterized by Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance spectroscopy, combined size-exclusion chromatography and multiangle laser light scattering analysis. Two drugs with distinct water solubility, prednisone acetate and tegafur, were encapsulated in the PHEA-g-PTMC nanoparticles. The in vitro release of two drugs from PHEA-g-PTMC nanoparticle drug-delivery systems was investigated.

Utilizing photoregenerated cofactors in conjunction with enzymes in a sequential manner presents an effective approach for the synthesis of targeted compounds in gentle reaction conditions. Nevertheless, the integration of enzymes and photocatalysts has faced challenges due to the swift breakdown of biomaterials caused by high‐energy or blue lights and photoinduced reactive oxygen species, leading to the denaturation and deactivation of enzymatic materials. This study details the deliberate development and production of hairy hollow conjugated microporous polymers (S‐hPrTZ‐P HCMPs), achieved via Sonogashira–Hagihara coupling on SiO2 templates, followed by sulfonation, polymer grafting and ultimately eliminating the SiO2 cores. This technique leverages the distinctive characteristics of low‐energy near‐infrared light, such as its superior penetration ability, to effectively regenerate the enzymatic cofactor NAD+ from NADH. It can accomplish this feat even when faced with synthetic or biological barriers that are impermeable to visible light. Simultaneously, photogenerated reactive oxygen species are captured and neutralized by the hydrophilic polymer brushes, safeguarding the integrity of the enzymatic material. The adaptability of S‐hPrTZ‐P with photocatalytic properties is showcased alongside glucose 1‐dehydrogenase and glycerol dehydrogenase. This structure and morphology‐controlled strategy offers a promising pathway for various enzymatic photobiocatalysis employing stable, efficient, and reusable hairy HCMPs. [ABSTRACT FROM AUTHOR]

In recent decades, the rapid development of the global economy has led to a substantial increase in energy consumption, subsequently resulting in the emission of a significant quantity of toxic gases into the environment. So far, gas sensors based on polymer field-effect transistors (PFETs), a highly practical and cost-efficient strategy, have garnered considerable attention, primarily attributed to their inherent advantages of offering a plethora of material choices, robust flexibility, and cost-effectiveness. Notably, the development of functional organic semiconductors (OSCs), such as poly(3-hexylthiophene-2,5-diyl) (P3HT), has been the subject of extensive scholarly investigation in recent years due to its widespread availability and remarkable sensing characteristics. This paper provides an exhaustive overview encompassing the production, functionalization strategies, and practical applications of gas sensors incorporating P3HT as the OSC layer. The exceptional sensing attributes and wide-ranging utility of P3HT position it as a promising candidate for improving PFET-based gas sensors. [ABSTRACT FROM AUTHOR]

We fabricate polymer solar cells (PSCs) and modules by sheet‐to‐sheet slot‐die coating under air environment based on halogen‐free host solvent. How to upscale small‐area PSC to large‐area PSC module is demonstrated here. The opaque module exhibits the most superior performance among the slot‐die‐coated modules reported. The scaling of both the semitransparent top electrode and PSC module is a challenge due to the complex difficulties. In this study, the semitransparent MoO3/Ag/MoO3 top electrode is successfully upscaled to be in the large‐area semitransparent PSC module. Ag layer thickness as reflector in the tri‐layer electrode is used to tune the trade‐off between transmittance, conductivity, and the light absorption in the active layer. The matching combination of transmittance, absorption spectra of MoO3/Ag/MoO3 top electrode, and active layer is a main key of our approach greatly improving photovoltaic and optical performance. The power conversion efficiencies (PCEs) of the semitransparent PSC modules with Ag thickness of 25, 20, and 15 nm are 7.1%, 5.9%, and 4.4%, respectively. The corresponding average visible transmittance (AVT) values are 20.5%, 28.3%, and 36.1%, respectively. The transmittance values at 550 nm are ranging from 24% to 40%. According to the review of all the reported semitransparent modules (>10 cm2), our modules demonstrate the excellent trade‐off performance about two times better than the large‐area semitransparent PSC modules currently reported either based on the similar PCEs or AVTs. [ABSTRACT FROM AUTHOR]

Presents a study that investigated the electro-optical properties of polymer dispersed liquid crystal (PDLC) materials. Analysis of the transmittance of PDLC film; Observations on the microphase structure of PDLC films via scanning electron microscopy; Effect of liquid crystal domain size and microstructure on light scattering properties.

We have developed an improved small-angle X-ray scattering (SAXS) model and analysis methodology to quantitatively evaluate the nanostructures of a blend system. This method has been applied to resolve the various structures of self-organized poly(3-hexylthiophene) /C61-butyric acid methyl ester (P31-IT/PCBM) thin active layer in a solar cell from the studies of both grazing-incidence small-angle X-ray scattering (GISAXS) and grazing-incidence X-ray diffraction (GIXRID). Tuning the various length scales of PCBM-related structures by a different annealing process can provide a flexible approach and better understanding to enhance the power conversion of the P3HT/PCBM solar cell. The quantitative structural characterization by this method includes (1) the mean size, volume fraction, and size distribution of aggregated PCBM clusters, (2) the specific interface area between PCBM and P3HT, (3) the local cluster agglomeration, and (4) the correlation length of the PCBM molecular network within the P3HT phase. The above terms are correlated well with the device performance. The various structural evolutions and transformations (growth and dissolution) between PCBM and P3HT with the variation of annealing history are demonstrated here. This work established a useful SAXS approach to present insight into the modeling of the morphology of P3HT/PCBM film. In situ GISAXS measurements were also conducted to provide informative details of thermal behavior and temporal evolution of PCBM-related structures during phase separation. The results of this investigation significantly extend the current knowledge of the relationship of bulk heterojunction morphology to device performance. [ABSTRACT FROM AUTHOR]

A convenient and effective ‘ultrasonic dispersion method’ was used to fabricate vector/DNA complexes encapsulated microspheres. Polyamidoamine (PAMAM) dendrimer/DNA complexes protected by a water-soluble polymer, poly- α, β-[ N-(2-hydroxyethyl)-L-aspartamide] (PHEA), were encapsulated in a polymer film mainly composed of cholic acid functionalized star poly(DL-lactide), which degraded through surface erosion mechanism with a fast degradation rate. The PAMAM/DNA complexes encapsulated polymer film was then immersed in ethanol and ultrasonicated to afford the microspheres. The in vitro gene transfections showed PAMAM/DNA complexes protected by PHEA exhibited a much higher transfection activity compared with PAMAM/DNA complexes without the protection by PHEA. The expressions of pGL3-Luc in HEK293 cells could be effectively mediated by the polymer film and microspheres with the presence of PHEA. The ultrasonic dispersion method, which did not involve toxic organic solvents, could keep the bioactivity of DNA and offer good control over the size of microspheres. [ABSTRACT FROM AUTHOR]

Novel thermo-sensitive magnetomicelles that consist of a magnetic core, Fe3O4-oleic acid (Fe3O4-OA), and an amphiphilic surface layer of thermo-sensitive poly(oleic acid-co-N-isopropylacrylamide) P(OA-co-NIPAAm) co-polymer were prepared. Fe3O4 magnetic cores functionalized with double bonds of oleic acid were prepared by suspension–oxidation reaction. Subsequently, by the co-polymerization of hydrophilic NIPAAm, hydrophobic OA and the Fe3O4-OA magnetic core, the thermo-sensitive amphiphilic polymers (P(OA-co-NIPAAm)) were grafted to obtain Fe3O4-OA-g-P(OA-co-NIPAAm) nanoparticles. The surface polymeric layer of Fe3O4-OA-g-P(OA-co-NIPAAm) nanoparticles would self-assemble in aqueous media to form a micellar structure attributed to the amphiphilic P(OA-co-NIPAAm) polymers. The model drug, prednisone acetate, was loaded in the magnetomicelles and in vitro release behavior of loaded drug in magnetomicelles was further investigated, which showed a thermo-sensitive release behavior due to the thermo-sensitive structural changes of the micellar surface layer. [ABSTRACT FROM AUTHOR]

A series of cholesteryl end-capped biodegradable oligo/poly(trimethylene carbonate)s were synthesized and characterized. The end-capped oligomers/polymers were synthesized by the ring-opening polymerization of trimethylene carbonate (TMC) initiated by cholesterol bearing a hydroxyl group without adding any catalyst. The end-capped oligomers/polymers with different molecular weights were obtained by controlling the feed ratio of the initiator cholesterol to the monomer TMC. The cholesteryl end-capped oligomers/polymers were characterized by Fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), gel-permeation chromatography (GPC), differential scanning calorimetry (DSC) and polarizing light microscopy (PLM). Incorporation of cholesteryl moieties results in liquid crystallinity of the end-capped oligomers/polymers when their molecular weights are not very high. Using the MTT assay, the end-capped biodegradable oligo/poly(trimethylene carbonate) is proved to have a low cytotoxicity. The microsphere drug-delivery system of an end-capped polymer was fabricated and its drug-release properties were evaluated. [ABSTRACT FROM AUTHOR]

Crystallization of a polystyrene-b-poly(ethylene oxide)-b-polystyrene (S–EO–S) triblock copolymer, S40EO136S40, with lamellar morphology in the melt and low glass transition temperature (Tg=47 °C) of the S block was studied. The triblock copolymer was cooled from ordered melt and isothermal crystallization was conducted at crystallization temperatures (Tc) near the Tg of the S block. It is found that crystallization behavior of S40EO136S40 strongly depends on Tc. When Tc is far below Tg, an Avrami exponent n=0.5 is observed, which is attributed to diffusion-controlled confined crystallization. As Tc slightly increases, the Avrami exponent is 1.0, indicating that crystallization is confined and crystallization rate is determined by the rate of homogeneous nucleation. When Tc is just below the Tg of the S block, crystallization tends to become breakout and accordingly Avrami exponent changes from 1.0 to 3.2. Crystallinity and melting temperature of the EO block in breakout crystallization are slightly higher than those in confined crystallization. Time-resolved small and wide angle X-ray scattering (SAXS/WAXS) were used to monitor isothermal crystallization of S40EO136S40. It shows that the long period is constant in confined crystallization, but it gradually increases during breakout crystallization. WAXS result reveals that confined or breakout crystallization has no effect on the crystal structure of the EO block. [Copyright &y& Elsevier]

Highlights: [•] ITO-free PSCs fabricated by a combination of inkjet-printing and spray processes. [•] Ink-jet printed Ag grids covered with highly conductive PEDOT:PSS was used as anode. [•] Improved interfacial contact between Ag grids and active layer resulted in high PCE. [•] Improving performance of large-area (8cm2) PSCs is shown. [Copyright &y& Elsevier]

Abstract: In this paper, the use of hot solvent vapor (HSV) annealing is demonstrated to improve the performance of polymer solar cells (PSCs) fabricated by the spray process. The blend of poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester (P3HT/PCBM) is used as a photoactive layer of the solar cell. Compared to the conventional solvent vapor annealing, the HSV annealing can eliminate the formation of intra-droplet boundary during the spray process and optimize the nanostructure of the film quickly (≤5min). The study of conducting atomic force microscopy (C-AFM) reveals that the HSV annealed film exhibits smooth film surface and homogenous conductivity distribution. Moreover, an enhanced light harvesting and increased crystallinity of P3HT in the active layer are observed by UV–vis absorption and X-ray diffraction (XRD). With subsequent thermal annealing, the power conversion efficiency of solar cell made from the HSV annealed film is reached at 3.61%. This HSV annealing technique can be implemented into the fabrication of high efficient large-area PSCs using the spray process. [Copyright &y& Elsevier]

The structure of poly(9,9-dioctylfluorene-2,7-diyl) (PF8) in deuterated toluene solutions at concentrations ranging from 0.60% to 7.0% (w/v) has been investigated by means of small-angle neutron scattering (SANS) and nuclear magnetic resonance (NMR) spectroscopy. PF8 chains exhibited aggregation above 1.0%, where the corresponding SANS profiles were characterized by the superposition of an aggregate component and a dynamic component associated with the transient network formed by interchain overlap. The 1H NMR resonance lines for both the polymer as well as for the residual protons in the solvent showed large upfield shift at higher concentrations, indicating strong polymer−solvent interaction. At a higher concentration (4.5%) an additional resonance line was observed in the aromatic regions of both the 1H and the 2H spectra that has been attributed to a residual anisotropic chemical shift of the solvent molecules. The later phenomenon is suggestive of the existence of magnetically anisotropic aggregate domains of PF8 dispersed in an isotropic bulk. [ABSTRACT FROM AUTHOR]

Abstract: A four-arm star block copolymer, comprised of a hydrophobic PMMA arm and an average of three hydrophilic poly(N-isopropylacrylamide) (PNIPAAm) arms were designed and synthesized from the molecular level. The amphiphilic star block copolymer is capable of self-assembling into micelles in water, which was confirmed by FT-IR, 1H NMR and fluorescence spectroscopy. Transmission electron microscopy images showed that these nanoparticles were regularly spherical in shape. The micelles showed reversible dispersion/aggregation in response to temperature cycles through an outer polymer shell lower critical solution temperature (LCST) for PNIPAAm at around 34°C, observed by optical absorbance measurements. Resulted polymeric micelles loaded with prednisone acetate showed a much improved drug release behavior due to the special micellar structure. [Copyright &y& Elsevier]

Abstract: An amphiphilic AB block copolymer composed of poly(N-isopropylacrylamide) as a hydrophilic segment and poly(10-undecenoic acid) as a hydrophobic segment was synthesized. Cytotoxicity study of this copolymer exhibited no significant cytotoxicity. The lower critical solution temperature (LCST) of the copolymer was 30.8 °C, as determined by the turbidity method. The block copolymer forms micelles in an aqueous medium at the temperature lower than the LCST. Transmission electron microscopy images showed that these micelles were regularly spherical in shape. The micelle size determined by size analysis was around 160 nm. The anti-inflammation drug prednisone acetate was incorporated into the micelles and the release profiles of prednisone acetate showed a dramatic thermoresponsive switching behavior and a unique pH responsive behavior. Moreover, the pH responsive behavior was in relation to the thermoresponsive behavior. That is, the micelles were not pH sensitive at the temperature below the LCST, but the aggregates were pH sensitive at the temperature above the LCST. Based on these results, the thermo- and pH responsive micelles have great potential to be a novel carrier for drug delivery. [Copyright &y& Elsevier]

Abstract: In this study, wholly aromatic main chain copoly(ester–amide)s containing tetrafluorophthalic acid (TFPA-ortho), tetrafluoroisophthalic acid (TFIA-meta) and tetrafluoroterephthalic acid (TFTA-para) were synthesized to study the effects of kinks on the formation of mesophase and crystal texture. The effects of kink moieties on these copoly(ester–amide)s were also investigated by the ‘RIS’ metropolis Monte Carlo simulation. Computational results indicate that all systems form thermotropic liquid crystalline polymers (LCPs) because the calculated persistence ratios for the ortho-, meta- and para-linkage systems are 6.51, 7.64 and 10.49, respectively. Both simulation and experimental results agree that ABA/AAA/TFTA (para) system has the greatest tendency to yield the liquid crystal (LC) phase due to its greater persistence ratio, linearity, and chain stiffness. The incorporation of TFPA (ortho) moiety can effectively reduce 30% of the molar stiffness function and 23% of the persistence length as compared to those of the TFTA (para) system. Yet, the ABA/AAA/TFPA system may form LC texture because of its large, rigid, disk-like TFPA moiety and the crankshaft structure induced by cis-configuration between AAA and TFPA moieties. The meta-linkage system has a slower LC growth rate, but it has a much higher tendency to form LC than the ortho-linkage. Both meta- and para-linkage systems have close critical ABA content to form LC texture. When comparing the requirements of critical ABA content between ABA/AAA/TFIA and ABA/AAA/IA (isophthalic acid) systems, we surprisingly observed that the former has a much lower critical ABA content than the latter. The four fluorine substituents of TFIA definitely help chain rigidity and stabilize the LC mesogens. Even though these fluorinated moieties exhibit different conformations and configurations, they yield similar end-stage crystalline structure. The spherulites are grown from the dark brushes around a single disclination, indicating that these are the lowest energy for crystallization. [Copyright &y& Elsevier]