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Kristyna Kolouchova, Ondrej Sedlacek, Daniel Jirak, David Babuka, Jan Blahut, Jan Kotek, Martin Vít, Jiri Trousil, Rafal Konefal, Olga Janoušková, Bohumila Podhorska, Miroslav Slouf, Martin Hruby
Magnetic resonance imaging using fluorinated contrast agents (19 F MRI) enables enhanced resolution due to the negligible fluorine background in living tissues. In this pilot study, we developed new biocompatible, temperature-responsive and easy synthetized polymeric nanogels containing sufficient concentration of magnetically equivalent fluorine atoms for the 19 F MRI purposes. The sturcture of nanogels is based on amphiphilic copolymers containing two blocks - hydrophilic poly[ N-(2-hydroxypropyl)methacrylamide] (PHPMA) or poly(2-methyl-2-oxazoline) (PMeOx) block, respectively, and thermoresponsive poly[ N-(2,2-difluoroethyl)acrylamide] (PDFEA) block...
July 16, 2018: Biomacromolecules
Renpeng Gu, Thomas Oweida, Yaroslava G Yingling, Ashutosh Chilkoti, Stefan Zauscher
We synthesized long, nucleobase-modified, single-stranded DNA (ssDNA) using terminal deoxynucleotidyl transferase (TdT) enzymatic polymerization. Specifically, we investigated the effect of unnatural nucleobase size and incorporation density on ssDNA resistance to exo- and endonuclease degradation. We discovered that increasing the size and density of unnatural nucleobases enhances ssDNA resistance to degradation in the presence of Exonuclease I, DNase I, and human serum. We also studied the mechanism of this resistance enhancement using molecular dynamics simulations...
July 16, 2018: Biomacromolecules
Chiara Cristina Toma, Alessandra Aloisi, Valentina Bordoni, Riccardo Di Corato, Martina Rauner, Gianaurelio Cuniberti, Lucia Gemma Delogu, Rosaria Rinaldi
Alginate-(ALG) and chitosan-(CS) have been extensively used for biomedical applications; however, data relative to immune responses exerted by them are scarce. We synthesized a submicron vesicle system (SV) displaying a CS shell over an ALG core. Intravenous injection of these promising carriers could be a possible route of delivery; therefore, we evaluated their impact on human peripheral blood mononuclear cells (PBMCs). By this ex vivo approach, we established how SV chemical-physical characteristics affected the immune cells in terms of cellular uptake, viability and state of activation...
July 16, 2018: Biomacromolecules
Thai Minh Duy Le, Huu Thuy Trang Duong, Thavasyappan Thambi, V H Giang Phan, Ji Hoon Jeong, Doo Sung Lee
Despite great potential, the delivery of genetic materials into cells or tissues of interest remains challenging owing to their susceptibility to nuclease degradation, lack of permeability to the cell membrane, and short in vivo half-life, which severely restrict their widespread use in therapeutics. To surmount these shortcomings, we developed a bioinspired in situ-forming pH- and temperature-sensitive injectable hydrogel depot that could control the delivery of DNA-bearing polyplexes for versatile biomedical applications...
July 13, 2018: Biomacromolecules
Franck Quero, Genesis Opazo, Yadong Zhao, Aymeric Feschotte-Parazon, Jeimy Fernández, Abraham Mackenna, Marcos Flores
Protein-functionalized cellulose fibrils, having various amounts of covalently bonded proteins at their surface, were successfully extracted from the tunic of Pyura Chilensis tunicates using successive alkaline extractions. Pure cellulose fibrils were also obtained by further bleaching and were used as reference material. Extraction yields of protein-functionalized cellulose fibrils were within the range of 62-76% by weight based on the dry initial tunic powder. Fourier-transform infrared and Raman spectroscopy confirmed the preservation of residual protein at the surface of cellulose fibrils, which was then quantified by X-ray photoelectron spectroscopy...
July 13, 2018: Biomacromolecules
Lindsay E Matolyak, Chase B Thompson, Bingrui Li, Jong K Keum, Jonathan E Cowen, Richard S Tomazin, LaShanda T J Korley
Peptide-polymer hybrids combine the hierarchy of biological species with synthetic concepts to achieve control over molecular design and material properties. By further incorporating covalent cross-links, the enhancement of molecular complexity is achieved, allowing for both a physical and covalent network. In this work, the structure and function of poly(ethylene glycol) (PEG)-network hybrids are tuned by varying peptide block length and overall peptide content. Here the impact of poly(ε-carbobenzyloxy-l-lysine) (PZLY) units on block interactions and mechanics is explored by probing secondary structure, PEG crystallinity, and hierarchical organization...
July 12, 2018: Biomacromolecules
Yongliang Wang, Baoqiang Li, Feng Xu, Zhidong Han, Daqing Wei, Dechang Jia, Yu Zhou
As one of important biomaterials for localized drug delivery system, chitosan hydrogel still exist several challenges, including poor mechanical properties, passive drug release behavior and lack of remote stimuli response. To address these challenges, a facile in-situ hybridization method was reported for fabricate tough magnetic chitosan hydrogel (MCH), which remotely switched drug release from passive release to pulsatile release under a low frequency alternating magnetic field (LAMF). The in-situ hybridization method avoided the aggregation of magnetic nanoparticles (MNPs) in hydrogel, which simultaneously brings 416 % and 265 % increase in strength and elastic modulus, respectively...
July 11, 2018: Biomacromolecules
Sophie Houvenagel, Laurence Moine, Guilherme Fadel Picheth, Camille Dejean, Annie Brûlet, Alexis Chennevière, Vincent Faugeras, Nicolas Huang, Olivier Couture, Nicolas Tsapis
Imaging the enhanced permeation and retention effect by ultrasound is hindered by the large size of commercial ultrasound contrast agents (UCAs). To obtain nanosized UCAs, triblock copolymers of poly(ethylene glycol)-polylactide-poly(1H,1H,2H,2H-heptadecafluorodecyl methacrylate) (PEG-PLA-PFMA) with distinct numbers of perfluorinated pendant chains (5, 10 or 20) are synthesized by a combination of ring-opening polymerization and atom transfer radical polymerization. Nanocapsules (NCs) containing perfluorooctyl bromide (PFOB) intended as UCAs are obtained with a 2-fold increase in PFOB encapsulation efficiency in fluorinated NCs as compared to plain PEG-PLA NCs thanks to fluorous interactions...
July 11, 2018: Biomacromolecules
Duy-Khiet Ho, Sarah Frisch, Alexander Biehl, Emmanuel Terriac, Chiara De Rossi, Konrad Schwarzkopf, Franziska Lautenschlaeger, Brigitta Loretz, Xabier Murgia, Claus-Michael Lehr
Amphiphilic polymer-based drug delivery systems hold potential in enhancing pharmacokinetics and therapeutic efficacy due to their ability to simultaneously co-deliver different drugs in a controlled manner. We here propose a facile method to synthesize a new amphiphilic polymer, Farnesylated glycol chitosan (FGC), which self-assembles into nanoparticles upon being dispersed in aqueous media. The characteristics of FGC nanoparticles, in particular the size, could be tuned in a range from 200-500 nm by modulating the degree of Farnesylation, and the pH and polymer concentration during particle preparation...
July 10, 2018: Biomacromolecules
Fawad Jacobi, Alberto Camaleño de la Calle, Sophia Boden, Andrea Grafmueller, Laura Hartmann, Stephan Schmidt
We present a synthetic approach towards soft, glycooligomer-functionalized microgel particles mimicking carbohydrate presenting cell surfaces and analyze their specific binding to a model lectin (Concanavalin A, ConA). Focusing on multivalent presentation, a series of sequence-controlled glycooligomers with varying spacing and number of mannose units were synthesized and analyzed for the resulting glycooligomer-ConA affinity. Both, direct binding and inhibition studies show higher affinity with increasing number of sugar moieties but levelling off for higher valent systems indicating steric hindrance...
July 9, 2018: Biomacromolecules
Karolina Anna Kosakowska, Brittany Kaylee Casey, Julie N L Albert, Yang Wang, Henry S Ashbaugh, Scott Michael Grayson
A series of branched polymers, consisting of a poly(ethylene glycol) (PEG) core and lipophilic peripheral dendrons, were synthesized and their self-assembly into reverse micelles studied towards the ultimate goal of carrier-mediated transdermal drug delivery. More specifically, this investigation systematically explored the structure-property contributions arising from location and extent of branching by varying the number of branch points at the core and the generation of dendrons at the hydrophilic-hydrophobic interface...
July 9, 2018: Biomacromolecules
Karolina Anna Kosakowska, Brittany Kaylee Casey, Samantha Leigh Kurtz, Louise B Lawson, Scott Michael Grayson
The reverse micelle self-assembly of lipophile-functionalized poly(ethylene glycol) (PEG) dendrimer hybrids is probed for applications in carrier-mediated transdermal drug delivery. Under investigation are topologically diverse amphiphiles featuring controlled branching motifs at either the polymer core (one-, two- and four-arm PEG) and/or the hydrophilic-hydrophobic interface (peripheral dendritic generations 0 to 2). Thus, a systematic investigation of the effect of branching location (core versus peripheral) on carrier properties is described...
July 9, 2018: Biomacromolecules
Megumu Sakoda, Makoto Kaneko, Seiichi Ohta, Pan Qi, Shigetoshi Ichimura, Yutaka Yatomi, Taichi Ito
We have developed a new hydrogel hemostat composed of hyaluronan (HA) conjugated with inorganic polyphosphate (PolyP). A hemostatic hydrogel, HAX-PolyP, was formed rapidly by mixing aldehyde-modified HA and hydrazide-modified HA conjugated with PolyP (HA-PolyP). Although the gelation rate decreased with increasing PolyP content, the gelation time was below 5 min. In addition, the hydrogel swelling volume decreased with increasing PolyP content, but the degradation rate did not depend on PolyP content and the hydrogel underwent complete degradation through hydrolysis over 3 weeks in phosphate buffered saline...
July 9, 2018: Biomacromolecules
Gajendiran Mani, Sungjun Kim, Kyobum Kim
Development of folate (FA)-functionalized gold nanoparticles (AuNPs) has greatly increased in recent years due to their potential in cancer treatment. As surface functionalization of polymer-free AuNPs with thiol groups could result in agglomeration and precipitation, AuNPs should be stabilized with an efficient polymer. In this study, citric acid-PEG branched polymer (CPEG) acted as a reducing as well as stabilizing agent in the synthesis of AuNPs. The thiol group of thioglycolic acid (TGA) attached to CPEG-stabilized AuNPs and interacted with the free carboxylic acid group on the surface of TGA-AuNP nanoconjugates...
July 6, 2018: Biomacromolecules
Karine Glinel, Adam Behrens, Robert S Langer, Ana Jaklenec, Alain M Jonas
We demonstrate entrapment of the commensal skin bacteria Staphylococcus epidermidis in mats composed of soft nanotubes made by membrane-templated layer-by-layer (LbL) assembly. When cultured in broth, the resulting nanofibrillar patches efficiently delay the escape of bacteria and their planktonic growth, while displaying high steady-state metabolic activity. Additionally, the material properties and metabolic activity can be further tuned by post-processing the patches with additional polysaccharide LbL layers...
July 6, 2018: Biomacromolecules
Da Hye Kim, Hee Sook Hwang, Kun Na
A combination of chemo-photodynamic therapy has been manifested as a promising strategy for efficient cancer treatment due to the enhanced therapeutic efficacy. Here, we designed doxorubicin (DOX)-loaded photoresponsive micelles (DPRMs) based on a combination of chlorin e6 (Ce6) and lipoic acid (LA) conjugated methoxy-poly(ethylene) glycol (mPEG-Ce6, mPEG-LA) to achieve effective drug delivery using a single system. DPRMs were optimized with different molar ratios of mPEG-Ce6 and mPEG-LA which showed uniformly spherical morphology of size ∼130 nm and approximately 9% of DOX loading contents...
July 6, 2018: Biomacromolecules
Lina Nyström, Adam A Strömstedt, Artur Schmidtchen, Martin Malmsten
Here we report on covalently immobilized poly(ethyl acrylate-co-methacrylic acid) microgels loaded with the host defense peptide KYE28 (KYEITTIHNLFRKLTHRLFRRNFGYTLR), which is derived from human heparin cofactor II, as well as its poly(ethylene glycol)-conjugated (PEGylated) version, KYE28PEG. Peptide loading and release, as well as the consequences of these processes on the microgel and peptide properties, were studied by in situ ellipsometry, confocal microscopy, zeta potential measurements, and circular dichroism spectroscopy...
July 5, 2018: Biomacromolecules
Rui R Costa, Miguel González-Pérez, Marcos Herrero-Gutiérrez, Ricardo A Pires, Matilde Alonso, J Carlos Rodriguez-Cabello, Rui L Reis, Iva Pashkuleva
We introduce elastin-like recombinamers (ELRs) as polypeptides with precise amino acid positioning to generate polypeptide coatings with tunable rigidity. Two ELRs are used: V84-ELR, a hydrophobic monoblock, and EI-ELR, an amphiphilic diblock. Both were modified with the amine-reactive tetrakis (hydroxymethyl) phosphonium chloride compound. We evaluated the affinity, the conformation, and the dissipative behavior of ELRs assembled on alkanethiol self-assembled coatings by quartz crystal microbalance with dissipation monitoring, multi-parametric surface plasmon resonance, and atomic force microscopy...
July 3, 2018: Biomacromolecules
Madson R E Santos, Patrícia V Mendonça, Mariana C Almeida, Rita Branco, Armenio C Serra, Paula V Morais, Jorge F J Coelho
Infections caused by bacteria represent great motif of concern in health area. Therefore, there is a huge demand for more efficient antimicrobial agents. Antimicrobial polymers have attracted special attention as promising materials to prevent infectious diseases. In this study, a new polymeric system exhibiting antimicrobial activity against a range of Gram-positive and Gram-negative bacterial strains at micromolar concentrations (e.g., 0.8 µM) was developed. Controlled linear and star-shaped copolymers, comprising hydrophobic poly(butyl acrylate) (PBA) and cationic poly(3-acrylamidopropyl)trimethylammonium chloride) (PAMPTMA) segments, were obtained by SARA ATRP at 30 °C...
July 3, 2018: Biomacromolecules
Liam Martin, Raoul Peltier, Agnès Kuroki, James S Town, Sébastien Perrier
A range of well-defined guanidinium-rich linear polymers with demonstrable efficiency for cellular internalization were developed. A protected guanidinium-functional acrylamide monomer (di-Boc-guanidinium ethyl acrylamide, GEAdiBoc ) was synthesized and then polymerized via RAFT polymerization to yield well-defined homopolymers, which were then deprotected and functionalized with a fluorescein dye to observe and quantify their cellular uptake. The cellular uptake of these homopolymers was first compared to analogous polyarginines, which are commonly used in modern drug delivery...
July 3, 2018: Biomacromolecules
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