Form Of Poly Research Articles

Quantitative Comparison of the Hydration Capacity of Surface-Bound Dextran and Polyethylene Glycol.

We have quantified and compared the hydration capacity (i.e., capability to incorporate water molecules) of the two surface-bound hydrophilic polymer chains, dextran (dex) and poly(ethylene glycol) (PEG), in the form of poly(l-lysine)-graft-dextran (PLL-g-dex) and poly(l-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG), respectively. The copolymers were attached to a negatively charged silica-titania surface through the electrostatic interaction between the PLL backbone and the surface in neutral aqueous media. While the molecular weights of PLL and PEG were fixed, that of dex and the grafting density of PEG or dex on the PLL were varied. The hydration capacity of the polymer chains was quantified through the combined experimental approach of optical waveguide lightmode spectroscopy (OWLS) and quartz crystal microbalance with dissipation monitoring (QCM-D) to yield a value for areal solvation (Ψ), i.e., mass of associated solvent molecules within the polymer chains per unit substrate area. For the two series of copolymers with comparable stretched chain lengths of hydrophilic polymers, namely, PLL(20)-g-PEG(5) and PLL(20)-g-dex(10), the Ψ values gradually increased as the initial grafting density on the PLL backbone increased or as g decreased. However, the rate of increase in Ψ was higher for PEG than dextran chains, which was attributed to higher stiffness of the dextran chains. More importantly, the number of water molecules per hydrophilic group was clearly higher for PEG chains. Given that the -CH2CH2O- units that make up the PEG chains form a cage-like structure with 2-3 water molecules, these "strongly bound" water molecules can account for the slightly more favorable behavior of PEG compared to dextran in both aqueous lubrication and antifouling behavior of the copolymers.

Nrf2 Plays a Key Role in Erythropoiesis during Aging.

Aging is characterized by increased oxidation and reduced efficiency of cytoprotective mechanisms. Nuclear factor erythroid-2-related factor (Nrf2) is a key transcription factor, controlling the expression of multiple antioxidant proteins. Here, we show that Nrf2-/- mice displayed an age-dependent anemia, due to the combined contributions of reduced red cell lifespan and ineffective erythropoiesis, suggesting a role of Nrf2 in erythroid biology during aging. Mechanistically, we found that the expression of antioxidants during aging is mediated by activation of Nrf2 function by peroxiredoxin-2. The absence of Nrf2 resulted in persistent oxidation and overactivation of adaptive systems such as the unfolded protein response (UPR) system and autophagy in Nrf2-/- mouse erythroblasts. As Nrf2 is involved in the expression of autophagy-related proteins such as autophagy-related protein (Atg) 4-5 and p62, we found impairment of late phase of autophagy in Nrf2-/- mouse erythroblasts. The overactivation of the UPR system and impaired autophagy drove apoptosis of Nrf2-/- mouse erythroblasts via caspase-3 activation. As a proof of concept for the role of oxidation, we treated Nrf2-/- mice with astaxanthin, an antioxidant, in the form of poly (lactic-co-glycolic acid) (PLGA)-loaded nanoparticles (ATS-NPs) to improve its bioavailability. ATS-NPs ameliorated the age-dependent anemia and decreased ineffective erythropoiesis in Nrf2-/- mice. In summary, we propose that Nrf2 plays a key role in limiting age-related oxidation, ensuring erythroid maturation and growth during aging.

Intradermal Vaccination with PLGA Nanoparticles via Dissolving Microneedles and Classical Injection Needles

PurposeA dissolving microneedle array (dMNA) is a vaccine delivery device with several advantages over conventional needles. By incorporating particulate adjuvants in the form of poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) into the dMNA, the immune response against the antigen might be enhanced. This study aimed to prepare PLGA-NP-loaded dMNA and to compare T-cell responses induced by either intradermally injected aqueous-PLGA-NP formulation or PLGA-NP-loaded dMNA in mice.MethodsPLGA NPs were prepared with microfluidics, and their physicochemical characteristics with regard to encapsulation efficiencies of ovalbumin (OVA) and CpG oligonucleotide (CpG), zeta potentials, polydispersity indexes, and sizes were analysed. PLGA NPs incorporated dMNA was produced with three different dMNA formulations by using the centrifugation method, and the integrity of PLGA NPs in dMNAs was evaluated. The immunogenicity was evaluated in mice by comparing the T-cell responses induced by dMNA and aqueous formulations containing ovalbumin and CpG (OVA/CpG) with and without PLGA NP.ResultsPrepared PLGA NPs had a size of around 100 nm. The dMNA formulations affected the particle integrity, and the dMNA with poly(vinyl alcohol) (PVA) showed almost no aggregation of PLGA NPs. The PLGA:PVA weight ratio of 1:9 resulted in 100% of penetration efficiency and the fastest dissolution in ex-vivo human skin (< 30 min). The aqueous formulation with soluble OVA/CpG and the aqueous-PLGA-NP formulation with OVA/CpG induced the highest CD4 + T-cell responses in blood and spleen cells.ConclusionsPLGA NPs incorporated dMNA was successfully fabricated and the aqueous formulation containing PLGA NPs induce superior CD4+ and CD8+ T-cell responses.

Transitions between Nanoporous crystalline α and β forms of poly(2,6-dimethyl-1,4-phenylene) oxide (PPO)

Nanoporous-crystalline (NC) α and β forms of Poly(2,6-dimethyl-1,4-phenylene) oxide (PPO), exhibit two different large helix conformations, both being suitable for intrahelical low-molecular-mass guest inclusion. α → β and β → α transitions can be achieved by sorption of liquid β-guests and α-guests (i.e., of guest inducing β and α forms by solution casting and by sorption in amorphous PPO), respectively. Both α → β and β → α transitions occur with complete loss of possibly present crystalline phase orientations (both axial and planar). Moreover, the reported data show that transitions between the two phases and the associated loss of crystalline phase orientation occur only for guests being good PPO solvents. These observations rule out the possibility of solid–solid transitions while can be rationalized by mechanisms involving a local dissolution of the NC phases. This local polymer dissolution is followed by host/guest co-crystallization with the helical conformation being different from the starting one and more suitable to host the used guest. These data fully confirm complete separation between the two NC phases while rule out the hypothesis of a continuum of NC phases between two limit ones.

Macroporous Polymer Cantilever Resonators for Chemical Sensing Applications

AbstractA novel, cost‐effective strategy for sensing performance enhancement of cantilever‐shaped, mass‐sensitive sensors is presented. The developed strategy relies on the introduction of macroporosity in the recognition unit. The developed sensors are successfully applied in air humidity monitoring as well as in chemical sensing. As mass‐sensitive transducers, polymer microelectromechanical systems (MEMS) in the form of poly(vinylidene fluoride‐trifluoroethylene) [P(VDF‐TrFE)] cantilever resonators are specifically developed. These resonators are modified with a hierarchically structured macroporous poly(2,3′‐bithiophene) film, acting as a sensing layer. The design of the recognition layer takes advantage of the synergistic combination of inverse opal structuring, surface imprinting, and semi‐covalent imprinting of proteins. The resulting cantilever resonators are first successfully tested for air humidity monitoring in the whole relative humidity range (ca.10 – 90%). When the recognition layer is composed of human serum albumin‐imprinted polymer (HSA‐MIP) with a hierarchical structure, it can also be used as a selective chemosensor in a concentration range from 10 pM to 20 µM. The obtained results demonstrate that the macroporosity of the receptor film significantly enhances the sensor performance.

Controlled “one-pot” block copolymerization of β-butyrolactone and oxiranes via quantitative active centers transformation

The synthesis of block copolymers of oxiranes and β-butyrolactone based on a method of sequential monomer addition was developed. The anionic controlled polymerization of protected glycidol - ethoxyethyl glycidyl ether (EEGE) and β-butyrolactone (BBL) was used. By quantitatively transforming the hydroxyl groups at the ends of the polyoxirane chains to the carboxylate centers, a one-pot synthesis was possible without further purification of the intermediates. The main part of the study was directed toward verifying the degree of precision of the transformation step and copolymer synthesis and clarifying the role of hydroxyl groups potentially present during the polymerization of BBL. It was also found that the presence of a small excess of anhydride during the transformation reaction did not affect the subsequent synthesis steps. The use of a macroinitiator in the form of poly(ethylene glycol) allowed us to obtain well-defined block copolymers of oxiranes and BBL of di-, tri- and pentablock structures.

2,5‐Dimercapto‐1,3,4‐Thiadiazole (DMCT)‐Based Polymers for Rechargeable Metal–Sulfur Batteries

Organosulfur materials are a sustainable alternative to the present‐day layered oxide cathodes in lithium‐based batteries. One such organosulfur material that was intensely explored from the 1990s to early 2010s is 2,5‐dimercapto‐1,3,4‐thiadiazole (DMCT). However, research interest declined as the electrode reactions with DMCT were assumed to be too sluggish to be practical. Armed with the advances in metal–sulfur batteries, we revisit DMCT‐based materials in the form of poly[tetrathio‐2,5‐(1,3,4‐thiadiazole)], referred to as pDMCT‐S. With an appropriate choice of electrode design and electrolyte, pDMCT‐S cathode paired with a Li‐metal anode shows a capacity of 715 mA h g−1 and a Coulombic efficiency of 97.7% at a C/10 rate, thus quelling the concerns of sluggish reactions. Surprisingly, pDMCT‐S shows significantly improved long‐term cyclability compared to a sulfur cathode. Investigations into the origin of the stability reveals that the discharge product Li‐DMCT in its mesomeric form can strongly bind to polysulfides, preventing their dissolution into the electrolyte and shuttling. This unique mechanism solves a critical problem faced by sulfur cathodes. Encouragingly, this mechanism results in a stable performance of pDMCT‐S with Na‐metal cells as well. This study opens the potential for exploring other organic materials that have inherent polysulfide sequestering capabilities, enabling long‐life metal–sulfur batteries.

Improvement of optical, dielectric and mechanical properties of a new nanocomposite based on polyvinyl alcohol and layered double hydroxide

In this work, films in the form of poly (vinyl alcohol)/Layered Double Hydroxide (PVA/LDH) nanocomposites were synthesized with different amount of LDH (0%; 4% and 6%), and characterized by X-ray diffraction (XRD), infrared spectroscopy scanning electron microscopy (SEM), impedance spectroscopy and UV-Vis-NIR spectroscopy. Different characterizations were used to investigate the electrical/dielectric, optical and mechanical properties of the nanocomposite films XRD and infrared spectroscopy results showed that clay particles exist in the polymer matrix. Electrical modeling was established using an equivalent electrical circuit consisting of two blocks, and confirmed by fitting the experimental conductivity data according to Jonscher’s double power law. Moreover, the reinforcement of the composite matrix by the addition of LDH particles, showed a shift of the relaxations towards the low frequencies, and led to an increase of dielectric constant, conductivity, and absorption of the light in the ultraviolet domain with a decrease of the gap energy. As for the mechanical properties, namely the Young’s modulus, is tripled when the clay content is about 6%.

Poly (O-Aminophenol) Produced by Plasma Polymerization Has IR Spectrum Consistent with a Mixture of Quinoid &amp; Keto Structures

A vibrational analysis of various poly(o-aminophenol) structures has been undertaken using first principles methods. It is shown that a mixture of quinoid and keto forms of poly(o-aminophenol) gives rise to a simulated spectrum that replicates the experimental infrared spectra of plasma-produced poly(o-aminophenol) better than either the quinoid or keto poly(o-aminophenol) spectra alone. An unassigned peak in the spectrum is attributed to hydrogen bonding to the silica substrate.

Effect of morphology and molecular orientation on environmental water biodegradability of poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate

The biodegradation behaviors of several forms of poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (P(3HB-co-3HV)) in seawater and freshwater, namely, powder, cast film, undrawn fiber, and fivefold-drawn fiber, were analyzed via biochemical oxygen demand, weight loss, and scanning electron microscopy measurements. The powder showed the highest degradation rate, attributed to its larger surface area, which allows microorganisms to attach to the surface and form a biofilm that begins to degrade sooner. The fivefold-drawn fibers degraded more slowly than the undrawn fibers owing to the higher crystallinity caused by the orientation of the former. Moreover, the degradation results of the fivefold-drawn fibers in seawater and freshwater showed that the degradation rate depended on the number of microorganisms in both environmental water types. The analysis of the degradation behavior in the freshwater revealed that the crystalline and amorphous phases in the film degraded simultaneously, whereas the degradation of the fibers started from the amorphous phase, followed by the crystalline phase.

Influence of Thermal Annealing on the Sinterability of Different Grades of Polylactide Microspheres Dedicated for Laser Sintering.

We present a comparison of the influence of the conditioning temperature of microspheres made of medical grade poly(L-lactide) (PLLA) and polylactide with 4 wt % of D-lactide content (PLA) on the thermal and structural properties. The microspheres were fabricated using the solid-in-oil-in-water method for applications in additive manufacturing. The microspheres were annealed below the glass transition temperature (Tg), above Tg but below the onset of cold crystallization, and at two temperatures selected from the range of cold crystallization corresponding to the crystallization of the α’ and α form of poly(L-lactide), i.e., at 40, 70, 90, and 120 °C, in order to verify the influence of the conditioning temperature on the sinterability of the microspheres set as the sintering window (SW). Based on differential scanning calorimetry measurements, the SWs of the microspheres were evaluated with consideration of the existence of cold crystallization and reorganization of crystal polymorphs. The results indicated that the conditioning temperature influenced the availability and range of the SWs depending on the D-lactide presence. We postulate the need for an individual approach for polylactide powders in determining the SW as a temperature range free of any thermal events. We also characterized other core powder characteristics, such as the residual solvent content, morphology, particle size distribution, powder flowability, and thermal conductivity, as key properties for successful laser sintering. The microspheres were close to spheres, and the size of the microspheres was below 100 µm. The residual solvent content decreased with the increase of the annealing temperature. The thermal conductivities were 0.073 and 0.064 W/mK for PLA and PLLA microspheres, respectively, and this depended on the spherical shape of the microspheres. The wide angle X-ray diffraction (WAXD) studies proved that an increase in the conditioning temperature caused a slight increase in the crystallinity degree for PLLA microspheres and a clear increase in crystallization for the PLA microspheres.

Thermoresponsive Glycopolymers Based on Enzymatically Synthesized Oligo-β-Mannosyl Ethyl Methacrylates and N-Isopropylacrylamide.

We present here a series of thermoresponsive glycopolymers in the form of poly(N-isopropylacrylamide)-co-(2-[β-manno[oligo]syloxy] ethyl methacrylate)s. These copolymers were prepared from oligo-β-mannosyl ethyl methacrylates that were synthesized through enzymatic catalysis, and were subsequently investigated with respect to their aggregation and phase behavior in aqueous solution using a combination of 1H NMR spectroscopy, dynamic light scattering, cryogenic transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). The thermoresponsive glycopolymers were prepared by conventional free radical copolymerization of different mixtures of 2-(β-manno[oligo]syloxy)ethyl methacrylates (with either one or two saccharide units) and N-isopropylacrylamide (NIPAm). The results showed that below the lower critical solution temperature (LCST) of poly(NIPAm), the glycopolymers readily aggregate into nanoscale structures, partly due to the presence of the saccharide moieties. Above the LCST of poly(NIPAm), the glycopolymers rearrange into a heterogeneous mixture of fractal and disc/globular aggregates. Cryo-TEM and SAXS data demonstrated that the presence of the pendant β-mannosyl moieties in the glycopolymers induces a gradual conformational change over a wide temperature range. Even though the onset of this transition is not different from the LCST of poly(NIPAm), the gradual conformational change offers a variation of the temperature-dependent properties in comparison to poly(NIPAm), which displays a sharp coil-to-globule transition. Importantly, the compacted form of the glycopolymers shows a larger colloidal stability compared to the unmodified poly(NIPAm). In addition, the thermoresponsiveness can be conveniently tuned by varying the sugar unit-length and the oligo-β-mannosyl ethyl methacrylate content.

Green synthesised silver nanoparticles incorporated electrospun poly(methyl methacrylate) nanofibers with different architectures for ophthalmologic alternatives

Silver nanoparticles with 5–10 nm diameters are synthesised using Couroupita guianensis flower extract. The synthesised silver nanoparticles found to show good antimicrobial activity against gram negative and gram positive bacteria. Poly(methyl methacrylate) nanofibers with pristine, surface roughened and coaxial hollow forms are prepared by electrospinning. The structural and morphological properties of these pure and structurally modified poly(methyl methacrylate) nanofibers are evidenced by various analytical techniques. The antimicrobial studies of poly(methyl methacrylate) nanofibers having different architectures incorporated with silver nanoparticles are carried out. It is found that, all the three forms of poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show antibacterial properties against both gram positive and gram negative bacteria. Among these, surface roughened poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show highest antibacterial activity than the other two structural forms. The present study offers an alternative to the existing optical lenses. People especially those who suffer from eye problems can protect their eyes in a better way from infectious agents by wearing optical lens made from C. guianensis stabilised silver nanoparticles incorporated poly(methyl methacrylate) nanofibers than that made from pure poly(methyl methacrylate) nanofibers or films.

Piperidinium-Functionalized Poly(Vinylbenzyl Chloride) Cross-linked by Polybenzimidazole as an Anion Exchange Membrane with a Continuous Ionic Transport Pathway

A bicomponent anion exchange membrane (AEM) in the form of poly(vinylbenzyl chloride) (PVBC) cross-linked by polybenzimidazole (PBI) and quaternized by N-methylpiperidine (NMPD) is provided. On the...

Flocculating and dewatering of kaolin suspensions with different forms of poly(acrylamide‐co‐diallyl dimethylammonium chloride)

AbstractRecently, polymeric nanofibres have been considered for the rapid flocculation and dewatering of oil sands tailings. Apparently due to their fast initial interaction with the suspended fine particles, polymer nanofibres performed better than their parent water‐soluble polymer solutions. To further understand this mechanism, a model study was conducted using kaolin suspensions and poly(acrylamide‐co‐diallyl dimethylammonium chloride) nanofibres and powders. The initial settling rate, supernatant turbidity, water recovery, capillary suction time, and solids content were measured to determine the effect of using nanofibres on solid‐liquid separation. Nanofibres performed similarly to, or better than, equivalent polymer solutions in terms of initial settling rate and supernatant clarity at higher dosages and kaolin loadings. The kaolin studies showed that polymer nanofibres could absorb onto clay particles faster, and produce bigger flocs more rapidly, supposedly due to their high surface area to volume ratio. Our results indicate that polymer nanofibres, as well as polymer powders, may be successfully used to treat mature fine tailings produced from oil sands.

Guest induced transition from β to α nanoporous crystalline forms of PPO

The stability of α and β nanoporous-crystalline (NC) forms of Poly(2,6-dimethyl-1,4-phenylene) oxide (PPO), in the presence of guest molecules leading to crystallization in α and β-form (α and β-guests), is explored. Sorption of liquid guests at 30 °C and 60 °C is studied both for NC films and NC aerogels. WAXD and FTIR characterizations show that, for all considered conditions, NC α-phases after guest sorption/desorption remain unaltered. NC β-phases, on the contrary, after α-guest sorption can be transformed in co-crystalline (CC) α-phases that after guest desorption are transformed in NC α-phases. All conducted experiments also show that possible planar orientations of NC films (c//or c⊥ orientations) remain essentially unaltered, after sorption of all considered guest molecules. The presently discovered β→α transition constitutes a route to obtain unoriented α-form films, which till now were not available by known preparation procedures.

Thiolated Nanoparticles Overcome the Mucus Barrier and Epithelial Barrier for Oral Delivery of Insulin.

Oral administration is an ideal alternative for drug delivery due to its convenience and safety. However, oral protein delivery is limited by biological barriers such as the mucus barrier and epithelial barrier, which hamper drugs from entering the blood successfully. Here we presented PC6/CS NPs, a thiolated-polymer-based nanodrug delivery system in the form of poly(acrylic acid)-cysteine-6-mercaptonicotinic acid (PAA-Cys-6MNA, PC6), which is a kind of preactivated thiolated polymer, coated on chitosan (CS) nanoparticles (NPs). Its ability to overcome the mucus barrier and epithelial barrier was investigated. The existence of PC6 made the NPs prone to penetrate the mucus layer as well as strengthened the transcellular transport of insulin on epithelial cells. PC6/CS NPs efficiently enhanced the oral bioavailability of insulin to 16.2%. The improvement resulted from the function of PC6: (1) "diluting" mucus to promote nanoparticle penetration, (2) opening a tight junction to help insulin transport via the paracellular pathway, (3) making the nanoparticle more electrically neutral during the penetration process, and (4) uncoating from PC6/CS NPs so that positive CS NPs were adhered and uptaken by epithelial cells. Our study proves that PC6/CS NPs, which can achieve mucus penetration and epithelial permeation efficiently, are a potential nanocarrier for oral protein delivery.

Poly(ethylene glycol) crosslinked multi-armed poly(ε-benzyloxycarbonyl-L-lysine)s as super-amphiphiles: Synthesis, self-assembly, and evaluation as efficient delivery systems for poorly water-soluble drugs

Polymeric micelles with high thermodynamic stability and loading capacity are of tremendous significance for their potential applications in drug delivery. In the present study, super-amphiphiles in the form of poly(ethylene glycol)-crosslinked multi-armed polyethylenimine-g-poly(ε-benzyloxycarbonyl-L-lysine)s (PEZ-alt-PEG) were designed, synthesized, and optimized as nanocarriers for hydrophobic drugs. In an aqueous solution, the copolymer PEZ-alt-PEG self-assembled into sub-100-nm spherical shell crosslinked micelles with low toxicity in vitro and in vivo. The crosslinked super-amphiphilic structure of PEZ-alt-PEG could not only enhance the thermodynamic stability of polymeric micelles, but it could also significantly improve the loading capacity of hydrophobic drugs, such as curcumin (CUR). CUR-loaded PEZ-alt-PEG micelles could mediate effective drug delivery with sustained and complete CUR release. The use of PEZ-alt-PEG micellar nanocarriers remarkably improved the cellular uptake of CUR and therefore exhibited effective inhibitory activity on the growth of human hepatoma (HepG2) cells. Compared to free CUR, CUR-loaded polymeric micelles significantly accelerated the apoptosis rate of HepG2 cells. Therefore, PEZ-alt-PEG polymeric micelles, with their high thermodynamic stability, high drug-loading capacity, enhanced drug uptake and improved pharmacodynamic effects, could serve as efficient and promising nanocarriers for poorly water-soluble drugs.

Biosynthesis and Characterization of Bioplastic Polyhydroxybutyrate from Halophilic Bacterium &lt;i&gt;Halomonas elongata&lt;/i&gt; BK-AB8

Bioplastics are biodegradable polymers which can be produced by bacteria. The production occurs when the bacteria grow in a medium containing a minimum amount of key nutrients, such as nitrogen, magnesium, and phosphorus but is rich of carbon source. It is known that some bacteria from the genusHalomonascan produce bioplastics compound such as polyhydroxybutyrate (PHB). This study focused to evaluate the potential ofHalomonas elongataBK-AB8 in producing PHB. The bacteria were grown on a medium containing nile red. The grown bacterial colony exhibited orange luminescence when exposed under UV light indicating that the bacteria was able to produce bioplastics. The bioplastic production was conducted by growing the bacteria in the modified growth medium at 37 °C for 22 hours with aeration rate of 150 rpm. The resulting bioplastic was extracted using a mixture of chloroform−NaOCl (1:1), and subsequently precipitated in methanol. The highest efficiency of bioplastics production byHalomonas elongataBK-AB8 was around 24.7% using glucose as the main carbon resource.1H-NMR,13C-NMR, and FTIR characterizations of the resulting bioplastic showed high similarities to the corresponding profiles of PHB, which is likely in the form of poly-(R)-hydroxybutyrate. Thermogravimetry Analysis (TGA) showed that the resulting PHB sample started to degrade at 210 °C. Further characterization by Differential Scanning Calorimetry (DSC) showed a melting temperature of PHB at 164 °C with a degree of crystallinity around 14.2%, which strongly indicates that PHB was successfully produced fromHalomonas elongataBK-AB8.

Effects of ladder structure on the electronic properties and field-effect transistor performance of Poly(benzobisimidazobenzophenanthroline)

Abstract A comparative study of the semi-ladder (BBB) and ladder (BBL) forms of poly(benzobisimidazobenzophenanthroline) and their binary blends shows that the ladder structure endows a smaller optical bandgap, greater electron delocalization and substantially enhanced electron transport. n-Channel organic field-effect transistors (OFETs) fabricated from the semi-ladder BBB were found to have an electron mobility of 1.5 × 10−3 cm2/V whereas similar ladder BBL OFETs had an electron mobility of 2.2 × 10−2 cm2/V, which is a 15-fold enhancement in electron transport in favor of the full ladder polymer analogue. The BBB and BBL OFETs had similar good stability in ambient air while their electrical characteristics were successfully simulated by using a SPICE model, revealing dramatically reduced source/drain contact resistance in the BBL devices. Compared to its ladder analogue BBL, semi-ladder BBB has been rarely studied in semiconductor devices, and hence the present observation of high electron mobility in BBB thin films with good stability in air suggest that it is also promising for developing various electronic and energy conversion/storage devices.