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Wei Zhao, Hang Thu Ta, Cheng Zhang, Andrew Keith Whittaker
Fluorine-containing polymeric materials are receiving increasing attention as imaging probes in fluorine-19 magnetic resonance imaging (19F MRI), for example to enable quantitative in vivo detection of cells. Here we describe the one-pot polymerization synthesis of 19F-containing functional poly(OEGA-co-TFEA)-b-poly(St-co-VBA) copolymers as a new class of fluorinated MRI agent. A range of nanoparticle morphologies, including spheres, worm-like particles and vesicles were formed as a consequence of polymerization-induced self-assembly (PISA)...
March 24, 2017: Biomacromolecules
Kazunori Ushimaru, Yoshimitsu Hamano, Hajime Katano
ε-Poly-l-lysine (ε-PL) is one of the few homopoly(amino-acid)s occurring in nature. ε-PL, which possesses multiple amino groups, is highly soluble in water, where it forms the antimicrobial polycationic chain (PL(n+)). Although the high water-solubility is advantageous for the use of ε-PL as a food preservative, it has limited the applicability of ε-PL as a biopolymer plastic. Here, we report on the preparation and availability of a water-insoluble complex formed with PL(n+) and an anionic surfactant, bis(2-ethylhexyl) sulfosuccinate (BEHS(-), is also commercialized as AOT) anion...
March 24, 2017: Biomacromolecules
Yashira M Zayas-Gonzalez, Benjamin J Ortiz, David M Lynn
We report the reactive layer-by-layer assembly of amine-reactive polymer multilayers using an azlactone-functionalized polymer and small-molecule diamine linkers. This approach yields crosslinked polymer/linker-type films that can be further functionalized, after fabrication, by treatment with functional primary amines, and provides opportunities to incorporate other useful functionality that can be difficult to introduce using other polyamine building blocks. Films fabricated using poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) and three model non-degradable aliphatic diamine linkers yielded reactive thin films that were stable upon incubation in physiologically relevant media...
March 23, 2017: Biomacromolecules
Qinghua Xu, Zhen Zhang, Chunsheng Xiao, Chaoliang He, Xuesi Chen
Injectable hydrogels have been widely investigated for applications in biomedical fields, for instance, as biomimetic scaffolds mimicking the extracellular matrix (ECM). In addition to as scaffolds for mechanical support and transferring of nutrients, the dynamic bioactivity of ECM is another critical factor that affects cell behavior. In this work, a novel injectable poly(l-glutamic acid)-based hydrogel decorated with RGD was fabricated. The presentation of RGD significantly enhanced the cell-matrix interaction and promoted cell adhesion and proliferation...
March 23, 2017: Biomacromolecules
Antonio Pereira, Ingrid C Hoeger, Ana Ferrer, Jorge Rencoret, José C Del Rio, Kristiina Kruus, Jenni Rahikainen, Miriam Kellock, Ana Gutiérrez, Orlando J Rojas
Lignins were isolated from spruce, wheat straw, and eucalyptus by using the milled wood lignin (MWL) method. Functional groups and compositional analyses were assessed via 2D NMR and (31)P NMR to realize their effect on enzyme binding. Films of the lignins were fabricated and ellipsometry, atomic force microscopy, and water contact angle measurements were used for their characterization and to reveal the changes upon enzyme adsorption. Moreover, lignin thin films were deposited on quartz crystal microgravimetry (QCM) and surface plasmon (SPR) resonance sensors and used to gain further insights into the lignin-cellulase interactions...
March 23, 2017: Biomacromolecules
Elvis Cudjoe, Mousa Younesi, Edward Cudjoe, Ozan Akkus, Stuart J Rowan
An electrochemical process has been used to compact cellulose nanocrystals (CNC) and access aligned micron-sized CNC fibers. Placing a current across aqueous solutions of carboxylic acid functionalized CNCs (t-CNC-COOH) or carboxylic acid/primary amine functionalized CNCs (t-CNC-COOH-NH2) creates a pH gradient between the electrodes, which results in the migration and concentration of the CNC fibers at their isoelectric point. By matching the carboxylic acid/amine ratio of CNCs and collagen (ca. 30:70 carboxylic acid:amine ratio), it is possible to coelectrocompact both nanofibers and access aligned nanocomposite fibers...
March 22, 2017: Biomacromolecules
Qingxue Sun, Tarun Ojha, Fabian Kiessling, Twan Lammers, Yang Shi
Tumor-targeted nanomedicines have been extensively applied to alter the drawbacks and enhance the efficacy of chemotherapeutics. Despite the large number of preclinical nanomedicine studies showing initial success, their therapeutic benefit in the clinic has been rather modest, which is partially due to the inefficient tumor penetration caused by tumor microenvironment (high density of cells and extracellular matrix, increased interstitial fluid pressure). Furthermore, tumor penetration of nanomedicines is significantly influenced by physicochemical characteristics such as size, surface chemistry and shape...
March 22, 2017: Biomacromolecules
Alexey Khakalo, Ilari Filpponen, Orlando J Rojas
The state of dispersion and the interactions between a polymer and a filler in a nanocomposite crucially define its properties and performance. The affinity of polylactide (PLA) with vegetable and animal proteins (casein, gelatin, soy protein isolate, and hydrolysate) is investigated and their role as eco-friendly dispersants and compatibilizers of cellulose nanofibrils (CNF) is elucidated. The affinity of the proteins with PLA is determined by using sensograms acquired by electroacoustic (quartz crystal microgravimetry) and optical (surface plasmon resonance) techniques...
March 22, 2017: Biomacromolecules
Thomas Paulraj, Anastasia V Riazanova, Kun Yao, Richard L Andersson, Anette Müllertz, Anna J Svagan
Green, all-polysaccharide based microcapsules with mechanically robust capsule walls and fast, stimuli-triggered and switchable permeability behaviour show great promise in applications based on selective and timed permeability. Taking cue from nature, the build-up and composition of plant primary cell wall inspired the capsule wall assembly, because the primary cell walls in plants exhibit high mechanical properties despite being in a highly hydrated state, primarily owing to cellulose microfibrils. The microcapsules (16 ± 4 µm in diameter) were fabricated using the Layer-by-Layer technique on sacrificial CaCO3 templates, using plant polysaccharides (pectin, cellulose nanofibers and xyloglucan) only...
March 21, 2017: Biomacromolecules
Quan Wang, Ruirui Zhang, Mingzi Lu, Guoxing You, Ying Wang, Gan Chen, Caiyan Zhao, Zhen Wang, Xiang Song, Yan Wu, Lian Zhao, Hong Zhou
Oxidative side reaction is one of major factors hindering the development of hemoglobin-based oxygen carriers (HBOCs). To avoid the oxidative toxicity, we designed and synthesized polydopamine coated hemoglobin (Hb-PDA) nanoparticles via simple one-step assemblage without any toxic reagent. Hb-PDA nanoparticles showed oxidative protection of Hb by inhibiting the generation of methemoglobin (MetHb) and ferryl (Fe IV) Hb, as well as excellent antioxidant properties by scavenging free radicals and reactive oxygen species (ROS)...
March 21, 2017: Biomacromolecules
Ruiwei Guo, Qian Su, Jinwei Zhang, Anjie Dong, Cunguo Lin, Jianhua Zhang
Multifunctional and multi-responsive hydrogels have presented a promising platform to design and fabricate smart devices for application in a wide variety of fields. However, their preparations often involve multistep preparation of multi-responsive polymer precursors, tedious reactions to introduce functional groups or sophisticated molecular designs. In this work, a multifunctional boronic acid-based crosslinker bis(phenylboronic acid carbamoyl) cystamine (BPBAC) was readily prepared from inexpensive commercially available 3-carboxylphenylboronic acid (CPBA) and cystamine dihydrochloride, which has the ability to crosslink the cis-diols and catechol-containing hydrophilic polymers to form hydrogels...
March 21, 2017: Biomacromolecules
Assaf J Harnoy, Marina Buzhor, Einat Tirosh, Rona Shaharabani, Roy Beck, Roey J Amir
Self-assembled nanostructures and their stimuli-responsive degradation have been recently explored to meet the increasing need for advanced biocompatible and biodegradable materials for various biomedical applications. Incorporation of enzymes as triggers that can stimulate the degradation and disassembly of polymeric assemblies may be highly advantageous owing to their high selectivity and natural abundance in all living organisms. One of the key factors to consider when designing enzyme-responsive polymers is the ability to fine-tune the sensitivity of the platform toward its target enzyme in order to control the disassembly rate...
March 21, 2017: Biomacromolecules
Xiuwen Guan, Zhaopei Guo, Tinghong Wang, Lin Lin, Jie Chen, Huayu Tian, Xuesi Chen
In this study, a pH-responsive detachable polyethylene glycol (PEG) shielding strategy was designed for gene delivery in cancer therapy. Polyethylenimine/DNA complex (PEI/DNA) was in situ shielded by aldehyde group-modified PEG derivatives. The aldehyde groups of PEG could react with the amino groups of PEI by Schiff base reaction. The Schiff base bond was stable in neutral pH but labile in slightly acidic pH, which made the PEG sheddable in tumors. PEG-coated nanoparticles (NPs) had distinct advantages compared to their mPEG counterpart, possessing decreased zeta potential, more compressed size, and enhanced stability...
March 20, 2017: Biomacromolecules
Maria Angela Castriciano, Roberto Zagami, Maria Pia Casaletto, Bernard Martel, Mariachiara Trapani, Andrea Romeo, Valentina Villari, Maria Teresa Sciortino, Laura Grasso, Salvatore Guglielmino, Luigi Monsù Scolaro, Antonino Mazzaglia
In the development of new antibacterial therapeutic approaches to fight multidrug-resistant bacteria, antimicrobial photodynamic therapy (aPDT) represents a well-known alternative to treat local infections caused by different microorganisms. Here we present a polypropylene (PP) fabric finished with citrate-hydroxypropyl-βCD polymer (PP-CD) entrapping the tetra-anionic 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphine (TPPS) as photosensitizer-eluting scaffold (PP-CD/TPPS) for aPDT. The concept is based on host-guest complexation of porphyrin in the cavities of CDs immobilized on the PP fibers, followed by its sustained and controlled delivery in release medium and simultaneous photoinactivation of microorganisms...
March 20, 2017: Biomacromolecules
Doreen Chan, Anthony C Yu, Eric A Appel
There has been growing interest in producing stable, biocompatible nanocarriers for the controlled delivery of therapeutics. With micelles, it remains a challenge to predict a priori the size, aggregation number, and functionality of the self-assembled aggregates. Utilizing controlled radical polymerization techniques, we have prepared tunable high molecular weight amphiphilic comb copolymers that self-assemble into unimolecular "micelle-like" nanocarriers of predictable size and functionality. Excellent control over self-assembly behavior and structure allows for systematic determination of the role of important polymeric material properties (i...
March 17, 2017: Biomacromolecules
Chunhai Li, Shanshan Luo, Jianfeng Wang, Hong Wu, Shaoyun Guo, Xi Zhang
Self-assembly nucleators have been increasingly used to manipulate the crystallization of PLLA due to their strong intermolecular interaction with PLLA, while the molecular mechanism of such interaction is still unrevealed. In present work, one special self-assembly nucleator (TMC-300) with relatively high solubility in PLLA matrix, is chosen to investigate how the interaction works at molecular level to promote the crystallization of PLLA mainly through time-resolved spectroscopy. The results indicate that due to the dipole-dipole NH…O=C interaction between dissolved TMC-300 and PLLA, PLLA chains are transformed into gt conformer before TMC-300 phase-separating from PLLA melt, resulting in low energy barrier to pass for the following formation of PLLA α-crystal (α-crystal is consisted of gt conformer)...
March 16, 2017: Biomacromolecules
Jan Pille, Sanne A M van Lith, Jan C M van Hest, William P J Leenders
Recombinant llama heavy-chain antibody fragments (VHHs) are promising tools in the field of targeted nanomedicine. 7D12, a VHH against the epidermal growth factor receptor (EGFR) that is overexpressed in various cancers, has been evaluated as an effective cancer-targeting VHH in multiple studies. The small size of VHHs (15-20 kDa) results in a low circulation half-life, which can be disadvantageous for certain applications. A solution to this problem is to attach VHHs to the surface of nanoparticles to increase the hydrodynamic radius of the conjugate...
March 16, 2017: Biomacromolecules
Ahmad Rashad, Kamal Mustafa, Ellinor Bævre Heggset, Kristin Syverud
The current study aims to demonstrate the influence of the surface chemistry of wood-derived cellulose nanofibril (CNF) hydrogels on fibroblasts for tissue engineering applications. TEMPO-mediated oxidation or carboxymethylation pretreatments were employed to produce hydrogels with different surface chemistry. This study demonstrates the following: first, the gelation of CNF with cell culture medium and formation of stable hydrogels with improved rheological properties; second, the response of mouse fibroblasts cultured on the surface of the hydrogels or sandwiched within the materials with respect to cytotoxicity, cell attachment, proliferation, morphology, and migration...
March 16, 2017: Biomacromolecules
Bailey E Risteen, Alyssa Blake, Michael A McBride, Cornelia Rosu, Jung Ok Park, Mohan Srinivasarao, Paul S Russo, Elsa Reichmanis
Cellulose nanocrystals (CNCs) are bio-derived, rodlike particles that form a chiral nematic liquid crystal (LC) in water. In this work, CNCs were used to induce long-range order in a semiconducting polymer, poly[3-(potassium-4-butanoate) thiophene-2,5-diyl] (PPBT). It was found that PPBT, when mixed with CNCs, was incorporated into the liquid crystal "template" to form ordered structures with highly birefringent domains, as observed under polarized light. We show that the π-π interactions between polymer chains, which contribute considerably to the energetics of the semiconducting system, are directly influenced by the presence and packing of the liquid crystal phase...
March 15, 2017: Biomacromolecules
Jason M Walker, Emily Bodamer, Olivia Krebs, YuanYuan Luo, Alex P Kleinfehn, Matthew L Becker, David Dean
Two distinct molecular masses of poly(propylene fumarate) (PPF) are combined with an additive manufacturing process to fabricate highly complex scaffolds possessing controlled chemical properties and porous architecture. Scaffolds were manufactured with two polymer molecular masses and two architecture styles. Degradation was assessed in an accelerated in vitro environment. The purpose of the degradation study is not to model or mimic in vivo degradation, but to efficiently compare the effect of modulating scaffold properties...
March 14, 2017: Biomacromolecules
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