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  • 101.
    Olofsson, Kristina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Granskog, Viktor
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Cai, Yanling
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Activated dopamine derivatives as primers for adhesive-patch fixation of bone fractures2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 31, p. 26398-26405Article in journal (Refereed)
    Abstract [en]

    For the stabilization of complex bone fractures, tissue adhesives are an attractive alternative to conventional implants, often consisting of metal plates and screws whose fixation may impose additional trauma on the already fractured bone. This study reports on the synthesis and evaluation of activated dopamine derivatives as primers for fiber-reinforced-adhesive patches in bone-fracture stabilization strategies. The performance of synthesized dopamine derivatives are evaluated with regard to the adhesive shear strength of formed bone patches, as well as cell viability and surface properties. Dopamine-derived primers with methacrylamide, allyl, and thiol functional groups were found to significantly increase the adhesive shear strength of adhesive patches. Furthermore, deprotonation of the primer solution was determined to be essential in order to achieve good adhesion. In conclusion, the primer solutions that were found to give the best adhesion were the once where dopa-thiol was used in combination with either dopamethacrylamide or dopa-allyl, resulting in shear bond strengths of 0.29 MPa.

  • 102.
    Olofsson, Kristina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Granskog, Viktor
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Cai, Yanling
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Activated Dopamine Derivatives as Promising Primers for Adhesive-Patch Fixation of Bone FracturesManuscript (preprint) (Other academic)
  • 103.
    Olofsson, Kristina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Facile Synthesis of Dopa-Functional Polycarbonates viaThiol-Ene-Coupling Chemistry towards Self-Healing Gels2016In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 54, no 15, p. 2370-2378Article in journal (Refereed)
    Abstract [en]

    Since extraction of the naturally occurring mussel-foot proteins is expensive and time-consuming, routes towards synthetic analogues are continuously being explored. Often, these methods involve several protection and deprotection steps, making the synthesis of synthetic analogues time-consuming and expensive as well. Herein, we show that UV-initiated thiol-ene coupling between a thiol-functional dopamine derivative and an allyl-functional aliphatic polycarbonate can be used as a fast and facile route to dopa-functional materials. Different thiol-to-allyl ratios and irradiation protocols were used and it was found that nearly 50% of the allyl groups could be functionalized with dopa within short reaction times, without the need of protecting the catechol. It is also demonstrated herein that the dopa-functional polymers can be used to form self-healing gels through complexation with Fe3+ ions at increased pH.

  • 104.
    Olofsson, Kristina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    PEG-based hydrogels with well-defined network structures via UV-induced thiol-ene coupling: Synthesis and characterization2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Article in journal (Other academic)
  • 105.
    Olofsson, Kristina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Soft hydrogels from tetra-functional PEGs using UV-induced thiol-ene coupling chemistry: a structure-to-property study2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 57, p. 30118-30128Article in journal (Refereed)
    Abstract [en]

    In this work, photo-induced thiol-ene coupling (TEC) was used to produce well-defined poly(ethylene glycol) (PEG)-based hydrogels. PEGs of four different molecular weights (2k, 6k, 10k, and 20k) were functionalized with G1-allyl dendrons using anhydride chemistry to produce tetra-functional TEC crosslinkable PEGs. The tetra-functional PEGs were subsequently crosslinked with a tri-functional thiol in ethanol to form hydrogels. The synthesized hydrogels were characterized with respect to swelling behaviour, rheological properties and hydrolytic degradation. It was found that the molecular weight of the PEG chain greatly influences the final properties of the hydrogel, where a higher molecular weight of PEG gives an increased weight swelling ratio from 240% for PEG-2k hydrogels to 1400% for PEG-20k hydrogels, as well as decreased elastic moduli, with Young's moduli ranging from 106 MPa to 6 MPa, for PEG-2k and PEG-20k hydrogels, respectively. It was also found that the hydrolytic stability in alkaline conditions (pH 10) decreased when the molecular weight of PEG in the hydrogels increased.

  • 106.
    Olofsson, Kristina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Zhang, Yuning
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Dopa-Functionalized PEG-based Triblock-co-Polymers as Micelles towards Drug-Delivery ApplicationsManuscript (preprint) (Other academic)
  • 107.
    Olsson, J. V.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Garcia-Gallego, Sandra
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Fluoride-promoted carbonylation polymerization: A facile step-growth technique to polycarbonates2017In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 8, no 7, p. 4853-4857Article in journal (Refereed)
    Abstract [en]

    Fluoride-Promoted Carbonylation (FPC) polymerization is herein presented as a novel catalytic polymerization methodology that complements ROP and unlocks a greater synthetic window to advanced polycarbonates. The overall two-step strategy is facile, robust and capitalizes on the synthesis and step-growth polymerization of bis-carbonylimidazolide and diol monomers of 1,3- or higher configurations. Cesium fluoride (CsF) is identified as an efficient catalyst and the bis-carbonylimidazolide monomers are synthesized as bench-stable white solids, easily obtained on 50-100 g scales from their parent diols using cheap commercial 1,1′-carbonyldiimidazole (CDI) as activating reagent. The FPC polymerization works well in both solution and bulk, does not require any stoichiometric additives or complex settings and produces only imidazole as a relatively low-toxicity by-product. As a proof-of-concept using only four diol building-blocks, FPC methodology enabled the synthesis of a unique library of polycarbonates covering (i) rigid, flexible and reactive PC backbones, (ii) molecular weights 5-20 kg mol-1, (iii) dispersities of 1.3-2.9 and (iv) a wide span of glass transition temperatures, from -45 up to 169 °C.

  • 108.
    Olsson, Johan V.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Cai, Yanling
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Garcia-Gallego, Sandra
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Reactive imidazole intermediates: simplified synthetic approach to functional aliphatic cyclic carbonates2014In: Polymer Chemistry, ISSN 1759-9954, E-ISSN 1759-9962, Vol. 5, no 23, p. 6651-6655Article in journal (Refereed)
    Abstract [en]

    Reactive imidazole intermediates based on AB(2) and A(3) monomers, i.e. bis(methylol) propionic acid (bis-MPA) and trimethylolpropane (TMP) have successfully been synthesized and isolated on a 100 gram scale via a facile synthetic protocol using 1,1' -carbonyldiimidazole (CDI) as a key reagent. The robustness of the imidazole intermediates as bench stable precursors enabled the synthesis of a library of functional cyclic carbonates bearing relevant functionalities including hydrophilic PEGs, bioactive cholesterol and clickable groups. A number of functional polycarbonates were obtained by ring-opening polymerization, and their relevance in biomedical applications was highlighted by their low cytotoxicity on human dermal fibroblasts (hDF).

  • 109. Olsson, John V.
    et al.
    Hult, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Simplified and scalable synthetic methodology towards functional cyclic carbonate monomers and polymers2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Article in journal (Other academic)
  • 110. Ropponen, J.
    et al.
    Hyvonen, Z.
    Ruponen, M.
    Jarvinen, K.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Synthesis of in vitro non-toxic 2,2-bis(methylol)propionic acid (Bis-MPA) dendrimers2008In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 34, no 1, p. S36-S36Article in journal (Refereed)
  • 111.
    Rozenbaum, Rene T.
    et al.
    Univ Groningen, Dept Biomed Engn, POB 196, NL-9700 AD Groningen, Netherlands.;Univ Med Ctr Groningen, POB 196, NL-9700 AD Groningen, Netherlands..
    Andrén, Oliver C. J.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    van der Mei, Henny C.
    Univ Groningen, Dept Biomed Engn, POB 196, NL-9700 AD Groningen, Netherlands.;Univ Med Ctr Groningen, POB 196, NL-9700 AD Groningen, Netherlands..
    Woudstra, Willem
    Univ Groningen, Dept Biomed Engn, POB 196, NL-9700 AD Groningen, Netherlands.;Univ Med Ctr Groningen, POB 196, NL-9700 AD Groningen, Netherlands..
    Busscher, Henk J.
    Univ Groningen, Dept Biomed Engn, POB 196, NL-9700 AD Groningen, Netherlands.;Univ Med Ctr Groningen, POB 196, NL-9700 AD Groningen, Netherlands..
    Malkoch, Michael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sharma, Prashant K.
    Univ Groningen, Dept Biomed Engn, POB 196, NL-9700 AD Groningen, Netherlands.;Univ Med Ctr Groningen, POB 196, NL-9700 AD Groningen, Netherlands..
    Penetration and Accumulation of Dendrons with Different Peripheral Composition in Pseudomonas aeruginosa Biofilms2019In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, no 7, p. 4327-4333Article in journal (Refereed)
    Abstract [en]

    Multidrug resistant bacterial infections threaten to become the number one cause of death by the year 2050. Development of antimicrobial dendritic polymers is considered promising as an alternative infection control strategy. For antimicrobial dendritic polymers to effectively kill bacteria residing in infectious biofilms, they have to penetrate and accumulate deep into biofilms. Biofilms are often recalcitrant to antimicrobial penetration and accumulation. Therefore, this work aims to determine the role of compact dendrons with different peripheral composition in their penetration into Pseudomonas aeruginosa biofilms. Red fluorescently labeled dendrons with pH-responsive NH3+ peripheral groups initially penetrated faster from a buffer suspension at pH 7.0 into the acidic environment of P. aeruginosa biofilms than dendrons with OH or COO- groups at their periphery. In addition, dendrons with NH3+ peripheral groups accumulated near the top of the biofilm due to electrostatic double-layer attraction with negatively charged biofilm components. However, accumulation of dendrons with OH and COO- peripheral groups was more evenly distributed across the depth of the biofilms than NH3+ composed dendrons and exceeded accumulation of NH3+ composed dendrons after 10 min of exposure. Unlike dendrons with NH3+ groups at their periphery, dendrons with OH or COO- peripheral groups, lacking strong electrostatic double-layer attraction with biofilm components, were largely washed-out during exposure to PBS without dendrons. Thus, penetration and accumulation of dendrons into biofilms is controlled by their peripheral composition through electrostatic double-layer interactions, which is an important finding for the further development of new antimicrobial or antimicrobial-carrying dendritic polymers.

  • 112.
    Stenström, Patrik
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Andrén, Oliver C. J.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Fluoride-promoted esterification (FPE) chemistry: A robust route to Bis-MPA dendrons and their postfunctionalization2016In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 21, no 3, article id 366Article in journal (Refereed)
    Abstract [en]

    Bifunctional dendrons based on 2,2-bis(methylol)propionic acid (bis-MPA) are highly desirable scaffolds for biomedical applications. This is due to their flawless nature and large and exact number of functional groups as well as being biodegradable and biocompatible. Herein, we describe a facile divergent growth approach to their synthesis from monobenzylated tetraethylene glycol and post functionalization utilizing fluoride-promoted esterification (FPE) chemistry protocols. The scaffolds, presenting selectively deprotectable hydroxyls in the periphery and at the focal point, were isolated on a multigram scale with excellent purity up to the fourth generation dendron with a molecular weight of 2346 Da in seven reactions with a total yield of 50%. The third generation dendron was used as a model compound to demonstrate its functionalizability. Selective deprotection of the dendron's focal point was achieved with an outstanding yield of 94%, and biotin as well as azido functionalities were introduced to its focal point and periphery, respectively, through FPE chemistry. Bulky disperse red dyes were clicked through CuAAC to the dendron's azido groups, giving a biotinylated dendron with multivalent dyes with a molecular weight of 6252 Da in a total yield of 37% in five reactions with an average yield of 82% starting from the third generation focally and peripherally protected dendron. FPE chemistry proved to be a superb improvement over previous protocols towards bis-MPA dendrons as high purity and yields were obtained with less toxic solvents and greatly improved monomer utilization.

  • 113.
    Stenström, Patrik
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hjorth, Erik
    Zhang, Yuning
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Andrén, Oliver C. J.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Guette-Marquet, Simon
    Schultzberg, Marianne
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Synthesis and in Vitro Evaluation of Monodisperse Amino-Functional Polyester Dendrimers with Rapid Degradability and Antibacterial Properties2017In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 18, no 12, p. 4323-4330Article in journal (Refereed)
    Abstract [en]

    Amine functional polymers, especially cationically charged, are interesting biomacromolecules for several reasons, including easy cell membrane entrance, their ability to escape endosomes through the proton sponge effect, spontaneous complexation and delivery of drugs and siRNA, and simple functionalization in aqueous solutions. Dendrimers, a subclass of precision polymers, are monodisperse and exhibit a large and exact number of peripheral end groups in relation to their size and have shown promise in drug delivery, biomedical imaging and as antiviral agents. In this work, hydroxyl functional dendrimers of generation 1 to 5 based on 2,2-bis(methylol)propionic acid (bis-MPA) were modified to bear 6 to 96 peripheral amino groups through esterification reactions with beta-alanine. All dendrimers were isolated in high yields and with remarkable monodispersity. This was successfully accomplished utilizing the present advantages of fluoride-promoted esterification (FPE) with imidazole-activated monomers. Straightforward postfunctionalization was conducted on a second generation amino functional dendrimer with tetraethylene glycol through NHS-amidation and carbonyl diimidazole (CDI) activation to full conversion with short reaction times. Fast biodegradation of the dendrimers through loss of peripheral beta-alanine groups was observed and generational- and dose-dependent cytotoxicity was evaluated with a set of cell lines. An increase. in neurotoxicity compared to hydroxyl-functional dendrimers was shown in neuronal cells, however, the dendrimers were slightly less neurotoxic than commercially available poly(amidoamine) dendrimers (PAMAMs). Additionally, their effect on bacteria was evaluated and the second generation dendrimer was found unique inhibiting the growth of Escherichia coli at physiological conditions while being nontoxic toward human cells. Finally, these results cement a robust and sustainable synthetic route to amino-functional polyester dendrimers with interesting chemical and biological properties.

  • 114.
    Stenström, Patrik
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Manzanares, D.
    Zhang, Yuning
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Ceña, V.
    Malkoch, Michael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Evaluation of amino-functional polyester dendrimers based on Bis-MPA as nonviral vectors for siRNA delivery2018In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 23, no 8, article id 2028Article in journal (Refereed)
    Abstract [en]

    Herein, we present the first evaluation of cationic dendrimers based on 2,2-bis(methylol)propionic acid (bis-MPA) as nonviral vectors for transfection of short interfering RNA (siRNA) in cell cultures. The study encompassed dendrimers of generation one to four (G1-G4), modified to bear 6-48 amino end-groups, where the G2-G4 proved to be capable of siRNA complexation and protection against RNase-mediated degradation. The dendrimers were nontoxic to astrocytes, glioma (C6), and glioblastoma (U87), while G3 and G4 exhibited concentration dependent toxicity towards primary neurons. The G2 showed no toxicity to primary neurons at any of the tested concentrations. Fluorescence microscopy experiments suggested that the dendrimers are highly efficient at endo-lysosomal escape since fluorescently labeled dendrimers were localized specifically in mitochondria, and diffuse cytosolic distribution of fluorescent siRNA complexed by dendrimers was observed. This is a desired feature for intracellular drug delivery, since the endocytic pathway otherwise transfers the drugs into lysosomes where they can be degraded without reaching their intended target. siRNA-transfection was successful in C6 and U87 cell lines using the G3 and G4 dendrimers followed by a decrease of approximately 20% of target protein p42-MAPK expression.

  • 115.
    Utsel, Simon
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Montañez, Maria I.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hed, Yvonne
    Ropponen, Jarmo
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    Tunable Bifunctional Dendronized Cellulose SurfacesManuscript (preprint) (Other academic)
  • 116. Vestberg, Robert
    et al.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Kade, Matthew
    Wu, Peng
    Fokin, Valery V.
    Sharpless, K. Barry
    Drockenmuller, Eric
    Hawker, Craig J.
    Role of architecture and molecular weight in the formation of tailor-made ultrathin multilayers using dendritic macromolecules and click chemistry2007In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 45, no 14, p. 2835-2846Article in journal (Refereed)
    Abstract [en]

    The high efficiency and mild reaction conditions associated with the Cu(I) catalyzed cycloaddition of azides and alkynes were exploited for the covalent layer-by-layer synthesis of dendritic thin films on silicon wafers. The preparation of azide and alkyne-terminated dendrimers based on bisMPA was accomplished by a divergent strategy; combinations of these monodisperse building blocks from the 2nd to the 5th generation were used for construction of the thin films. The layer-by-layer self assembly process proceeds under ambient conditions and was monitored by ellipsometry, XPS, and ATR-IR, which showed extremely regular growth of the dendritic thin films. Film thickness could be accurately controlled by both the size/generation number of the dendrimers as well as the number of layers. In comparison with linear analogues, the growth of the dendritic films was significantly more controlled and defect-free with each layer being thinner than the corresponding films prepared from the isomeric linear polymers, demonstrating the well-defined, three-dimensional nature of the dendritic architecture.

  • 117. Vestberg, Robert
    et al.
    Piekarski, Ashley M.
    Pressly, Eric D.
    Van Berkel, Kim Y.
    Malkoch, Michael
    Gerbac, Jeffrey
    Ueno, Nobuhiko
    Hawker, Craig J.
    A General Strategy for Highly Efficient Nanoparticle Dispersing Agents Based on Hybrid Dendritic Linear Block Copolymers2009In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 47, no 5, p. 1237-1258Article in journal (Refereed)
    Abstract [en]

    A modular approach to the synthesis of a library of hybrid dendriticlinear copolymers was developed based on RAFT polymerization from monodisperse dendritic macroRAFT agents. By accurately controlling the molecular weight of the linear block, generation number of the dendrimer and the nature of the dendritic chains ends, the performance of these hybrid block copolymers as dispersing agents was optimized for a range of nanoparticles. For titanium dioxide nanoparticles, dispersion in a poly(methyl methacrylate) matrix was maximized with a second generation dendrimer containing four carboxylic acid end groups, and the quality of dispersion was observed to be superior to commercial dispersing agents for TiO2. This approach also allowed novel hybrid dendritic-linear dispersing agents to be prepared for the dispersion of Au and CdSe nanoparticles based on disulphide and phosphine oxide end groups, respectively.

  • 118.
    Walter, Marie V.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Andrén, Oliver C. J.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Thermally stable and functional honeycomb films from linear dendritic hybrids derived from HEMA and Bis-MPAManuscript (preprint) (Other academic)
  • 119.
    Walter, Marie V.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Lundberg, Pontus
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Novel Macrothiols for the Synthesis of a Structurally Comprehensive Dendritic Library using Thiol-Ene Click Chemistry2011In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 49, no 13, p. 2990-2995Article in journal (Refereed)
    Abstract [en]

    The authors are grateful to the Swedish Research Council (VR) for its financial support (grants 2008-5609, 2006-3617, and 2009-3259).

  • 120.
    Walter, Marie V.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Lundberg, Pontus
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    A one component methodology for the fabrication of honeycomb films from biocompatible amphiphilic block copolymer hybrids: a linear-dendritic-linear twist2013In: Polymer Chemistry, ISSN 1759-9954, Vol. 4, no 9, p. 2680-2690Article in journal (Refereed)
    Abstract [en]

    The development of a facile method for the fabrication of breath figure (BF) films from hydrophobic polymers is gaining significant importance for their accessibility as templates in fields ranging from electronics and cell culturing to sensing and catalysis. By introducing polyester-based dendritic linkers, a library of micrometre sized honeycomb structures was successfully fabricated from amphiphilic linear-dendritic-linear hybrids comprising hydrophobic PCL or PLA and hydrophilic PEG blocks. From the array of produced films, the incorporation of a third generation dendritic linker was found to generate well-ordered honeycomb films in the several hundreds of micrometre range. This one component approach minimizes the number of unknown parameters and represents a fully reliable methodology for the fabrication of functional BFs from challenging and biocompatible polymers.

  • 121.
    Walter, Marie V.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Simplifying the synthesis of dendrimers: accelerated approaches2012In: Chemical Society Reviews, ISSN 0306-0012, E-ISSN 1460-4744, Vol. 41, no 13, p. 4593-4609Article, review/survey (Refereed)
    Abstract [en]

    Dendrimers are highly branched and monodisperse macromolecules that display an exact and large number of functional groups distributed with unprecedented control on the dendritic framework. Based on their globular structure, compared to linear polymers of the same molecular weight, dendrimers are foreseen to deliver extraordinary features for applications in areas such as cancer therapy, biosensors for diagnostics and light harvesting scaffolds. Of the large number of reports on dendrimer synthesis only a few have reached commercial availability. This limitation can be traced back to challenges in the synthetic paths including a large number of reaction steps required to obtain dendritic structures with desired features. Along with an increased number of reaction steps come not only increased waste of chemical and valuable starting materials but also an increased probability to introduce structural defects in the dendritic framework. This tutorial review briefly covers traditional growth approaches to dendrimers and mainly highlights accelerated approaches to dendrimers. A special focus capitalizes on the impact of the click chemistry concept on dendrimer synthesis and the promise it has to successfully accomplish highly sophisticated dendrimers, both traditional as well as heterofunctional, in a minimum number of chemical steps. It is clear that accelerated synthetic approaches are of greatest importance as these will encourage the scientific community to synthesize and access dendrimers for specific applications. The final goal of accelerated synthesis is to deliver economically justified dendritic materials for future applications without compromising the environmental perspective.

  • 122.
    Walter, Marie Valérie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Cheval, Nicolas
    Liszka, Olimpia
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Fahmi, Amir
    Hybrid One-Dimensional Nanostructures: One-Pot Preparation of Nanoparticle Chains via Directed Self-Assembly of in Situ Synthesized Discrete Au Nanoparticles2012In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 28, no 14, p. 5947-5955Article in journal (Refereed)
    Abstract [en]

    The fabrication of well-defined one-dimensional (1D) arrays is becoming a challenge for the development of the next generation of advanced nanodevices. Herein, a simple concept is proposed for the in situ synthesis and self-assembly of gold nanoparticles (AuNPs) into ID arrays via a one-step process. The results demonstrated the formation of nanoparticle chains (NPC) with high aspect ratio based on discrete Au nanoparticles stabilized by short thiol ligands. A model was proposed to explain the self-assembly based on the investigation of several parameters such as pH, solvent, temperature, and nature of the ligand on the 1D assembly formation. Hydrogen bonding was identified as a key factor to direct the self-assembly of the hybrid organic inorganic nanomaterials into the well-defined 1D nanostructures. This simple and cost-effective concept could potentially be extended to the fabrication of a variety of hybrid 1D nanostructures possessing unique physical properties leading to a wide range of applications including catalysis, bionanotechnology, nanoelectronics, and photonics.

  • 123.
    Walter, Marie Valérie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Pontus, Lundberg
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Honeycomb films from amphiphilic linear-dendritic-linear hybrids: effect of branching and of the block lengthManuscript (preprint) (Other academic)
  • 124. Wu, Peng
    et al.
    Malkoch, Michael
    Materials Research Laboratories, University of California.
    Hunt, Jasmine N.
    Vestberg, Robert
    Kaltgrad, Eiton
    Finn, M. G.
    Fokin, Valery V.
    Sharpless, K. Barry
    Hawker, Craig J.
    Multivalent, bifunctional dendrimers prepared by click chemistry2005In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, no 46, p. 5775-5777Article in journal (Refereed)
    Abstract [en]

    Unsymmetrical dendrimers, containing both mannose binding units and coumarin fluorescent units, have been prepared using click chemistry and shown to be highly efficient, dual-purpose recognition/detection agents for the inhibition of hemagglutination.

  • 125. Wu, Zhihua
    et al.
    Lundberg, Pontus
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Zhang, Yuning
    Zeng, Xianghui
    Feliu, Neus
    Fadeel, Bengt
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Nyström, Andreas M.
    Engineering biocompatible drug delivery systems based on dendritic polymers2012In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Article in journal (Other academic)
  • 126. Wu, Zhihua
    et al.
    Zeng, Xianghui
    Zhang, Yuning
    Feliu, Neus
    Lundberg, Pontus
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Fadeel, Bengt
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nyström, Andreas M.
    Linear-Dendritic Polymeric Amphiphiles as Carriers of Doxorubicin-In Vitro Evaluation of Biocompatibility and Drug Delivery2012In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 50, no 2, p. 217-226Article in journal (Refereed)
    Abstract [en]

    In our recent work, we have explored the formation of chemotherapeutic delivery vehicles constructed from four different amphiphilic linear-dendritic hybrid block copolymers. These micelles were found to form about 100-nm-sized structures that were capable of sequestering doxorubicin at loading efficiencies up to 22%. Here, the cellular toxicity of these biocompatible and biodegradable linear-dendritic hybrid materials was evaluated on two breast cancer cell lines and primary human macrophages. The micelles were found not to affect the cellular viability at concentrations below 35 mu g mL(-1). After drug loading, these constructs could deliver an efficient dose of drugs, resulting in significant decreases in cell viability. Kinetic studies indicated that the drug formulation in the poly-mer micelles slowed down the cell uptake compared with the nonformulated drug, but similar efficacy in viability reduction and cell apoptosis were found. Taken together, these linear-dendritic hybrid materials represent an interesting novel architecture for the construction of drug delivery systems. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 217-226, 2012

  • 127.
    Yang, Ting
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Long, Hui
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gamstedt, E. Kristofer
    Berglund, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Characterization of Well-Defined Poly(ethylene glycol) Hydrogels Prepared by Thiol-ene Chemistry2011In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 49, no 18, p. 4044-4054Article in journal (Refereed)
    Abstract [en]

    Considering the large number of applications for hydrogels, a better understanding of the relation between molecular structure and mechanical properties for well-defined hydrogel is essential. A new library has been compiled of poly(ethylene glycol) polymers (PEG) of different length end functionalized with diallyl, dithiol, and dimethacrylate, and crosslinked with complementary trifunctional crosslinkers. In this study, the hydrogels were initially analyzed by FT-Raman and NMR to study the conversion ratio of the functional groups. The effects of solvent type, solid content concentration, curing time and length of the PEG chains on the final leaching, swelling and tensile properties of the hydrogels were studied.

  • 128.
    Yang, Ting
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Sequential interpenetrating poly(ethylene glycol) hydrogels prepared by UV-initiated thiol–ene coupling chemistry2013In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 51, no 2, p. 363-371Article in journal (Refereed)
    Abstract [en]

    Poly(ethylene glycol) (PEG)-diallyls, ranging from 2 to 8 kDa, were successfully reacted with a trifunctional thiol crosslinker via thiol–ene coupling reaction to construct four different primary PEG hydrogels. These systems were used as scaffolds for the preparation of a library of sequential interpenetrating networks (SeqIPNs). The solid content of the secondary networks varied between 21 and 34% and was dependent on the length of the absorbing PEGs. The gel fractions for the IPNs were above 85%. Additionally, the lowest degree of swelling was found for the IPN based on 2-kDa PEG (315%), whereas the 8-kDa PEG IPN exhibited a value of 810%. The SeqIPN strategy facilitated hydrogel systems that cover a larger domain of tensile modulus (192–889 kPa) when compared with single hydrogel networks (175–555 kPa).

  • 129.
    Yang, Ting
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    The influence of diffusion time on the properties of sequential interpenetrating PEG hydrogels2013In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 51, no 6, p. 1378-1386Article in journal (Refereed)
    Abstract [en]

    Four sets comprising a total of 16 sequential interpenetrating network (SeqIPN) hydrogels were efficiently fabricated via UV initiated thiol-ene coupling chemistry and from 2 kDa or 8 kDa primary poly(ethylene glycol) (PEG) networks (S2 and S8). Each primary system delivered four different SeqIPNs constructed after 2, 4, 20, and 44 h diffusion of secondary network PEG precursors, 2 kDa and 8 kDa. This allowed the assessment of both mechanical and swelling properties for a wide range of novel hydrogels ranging from loosely crosslinked SeqIPN 8-8 to densely crosslinked SeqIPN 2-2 systems. All gel fractions of secondary networks were above 83% and 44 h of diffusion was found sufficient to fully saturate the primary networks. Disperse red functionalized PEGs (2 kDa and 8 kDa) were further used as probes to investigate the diffusion mechanisms. The impact of diffusion time on loosely crosslinked S8 network with a swelling degree of 970% and tensile modulus of 175 kPa displayed a significant change in the final properties. For instance, a 2 h diffusion of 2 kDa PEG precursors generated a SeqIPN 8-2:2 comprising a secondary network solid content of 34% with a water swelling degree 580% and a tensile modulus of 365 kPa. On saturation, that is, 44 h of diffusion, SeqIPN 2-8:44 exhibited 64% of secondary network solid content, a swelling capacity of 380% and over fourfold of tensile modulus (758 kPa) when compared with the primary network S8. SeqIPN hydrogel with the highest tensile modulus and lowest degree of water swelling was obtained after 44 h diffusion of 2 kDa PEG precursors within the densely crosslinked S2 primary network. In this case, SeqIPN 2-2:44 noted a water swelling capability of 280% and a tensile modulus over 1 MPa. The latter was twofold when compared with S2 with a tensile modulus of 555 kPa. Consequently, the diffusion time of secondary network is a promising parameter to control and that enables the fabrication of PEG hydrogels with a wider window of mechanical and swelling properties.

  • 130. Zeng, Xianghui
    et al.
    Zhang, Yuning
    Wu, Zhihua
    Lundberg, Pontus
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nystrom, Andreas M.
    Hyperbranched Copolymer Micelles as Delivery Vehicles of Doxorubicin in Breast Cancer Cells2012In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 50, no 2, p. 280-288Article in journal (Refereed)
    Abstract [en]

    Four types of drug nanoparticles (NPs) based on amphiphilic hyperbranched block copolymers were developed for the delivery of the chemotherapeutic doxorubicin (DOX) to breast cancer cells. These carriers have their hydrophobic interior layer composed of the hyperbranched aliphatic polyester, Boltorn (R) H30 or Boltorn (R) H40, that are polymers of poly 2,2-bis (methylol) propionic acid (bis-MPA), while the outer hydrophilic shell was composed of about 5 poly(ethylene glycol) (PEG) segments of 5 or 10 kDa molecular weight. A chemotherapeutic drug DOX, was further encapsulated in the interior of these polymer micelles and was shown to exhibit a controlled release profile. Dynamic light scattering and transmission electron microscopy analysis confirmed that the NPs were uniformly sized with a mean hydrodynamic diameter around 110 nm. DOX-loaded H30-PEG10k NPs exhibited controlled release over longer periods of time and greater cytotoxicity compared with the other materials developed against our tested breast cancer cell lines. Additionally, flow cytometry and confocal scanning laser microscopy studies indicated that the cancer cells could internalize the DOX-loaded H30-PEG10k NPs, which contributed to the sustained drug release, and induced more apoptosis than free DOX did. These findings indicate that the H30-PEG10k NPs may offer a very promising approach for delivering drugs to cancer cells. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 280-288, 2012

  • 131.
    Zhang, Yuning
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Andrén, Oliver C. J.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Nordström, R.
    Fan, Yanmiao
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Malmsten, M.
    Mongkhontreerat, S.
    Malkoch, Michael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Off-Stoichiometric Thiol-Ene Chemistry to Dendritic Nanogel Therapeutics2019In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, no 18, article id 1806693Article in journal (Refereed)
    Abstract [en]

    A novel platform of dendritic nanogels is herein presented, capitalizing on the self-assembly of allyl-functional polyesters based on dendritic-linear-dendritic amphiphiles followed by simple cross-linking with complementary monomeric thiols via UV initiated off-stoichiometric thiol-ene chemistry. The facile approach enabled multigram creation of allyl reactive nanogel precursors, in the size range of 190–295 nm, being readily available for further modifications to display a number of core functionalities while maintaining the size distribution and characteristics of the master batch. The nanogels are evaluated as carriers of a spread of chemotherapeutics by customizing the core to accommodate each individual cargo. The resulting nanogels are biocompatible, displaying diffusion controlled release of cargo, maintained therapeutic efficacy, and decreased cargo toxic side effects. Finally, the nanogels are found to successfully deliver pharmaceuticals into a 3D pancreatic spheroids tumor model. © 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  • 132. Zhang, Yuning
    et al.
    Lundberg, Pontus
    Diether, Maren
    Porsch, Christian
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Janson, Caroline
    Lynd, Nathaniel A.
    Ducani, Cosimo
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hawker, Craig J.
    Nystrom, Andreas M.
    Histamine-functionalized copolymer micelles as a drug delivery system in 2D and 3D models of breast cancer2015In: Journal of materials chemistry. B, ISSN 2050-750X, E-ISSN 2050-7518, Vol. 3, no 12, p. 2472-2486Article in journal (Refereed)
    Abstract [en]

    Histamine functionalized block copolymers based on poly(allyl glycidyl ether)-b-poly(ethylene oxide) (PAGE-b-PEO) were prepared with different ratios of histamine and octyl or benzyl groups using UV-initiated thiol-ene click chemistry. At neutral pH, the histamine units are uncharged and hydrophobic, while in acidic environments, such as in the endosome, lysosomes, or extracellular sites of tumours, the histamine groups are positively charged and hydrophilic. pH responsible polymer drug delivery systems is a promising route to site specific delivery of drugs and offers the potential to avoid side effects of systemic treatment. Our detailed in vitro experiments of the efficacy of drug delivery and the intracellular localization characteristics of this library of NPs in 2D and 3D cultures of breast cancer revealed that the 50% histamine-modified polymer loaded with DOX exhibited rapid accumulation in the nucleus of free DOX within 2 h. Confocal studies showed enhanced mitochondrial localization and lysosomal escape when compared to controls. From these combined studies, it was shown that by accurately tuning the structure of the initial block copolymers, the resulting self-assembled NPs can be designed to exploit histamine as an endosomal escape trigger and the octyl/benzyl units give rise to a hydrophobic core resulting in highly efficacious drug delivery systems (DDS) with control over intracellular localization. Optimization and rational control of the intracellular localization of both DDS and the parent drug can give nanomedicines a substantial increase in efficacy and should be explored in future studies.

  • 133. Zorn, Anna-Marie
    et al.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Carlmark Malkoch, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Barner-Kowollik, Christopher
    High temperature synthesis of vinyl terminated polymers based on dendronized acrylates: a detailed product analysis study2011In: POLYMER CHEMISTRY, ISSN 1759-9954, Vol. 2, no 5, p. 1163-1173Article in journal (Refereed)
    Abstract [en]

    The combination of dendrons and high temperature acrylate polymerization represents a viable route to form dendronized macromonomers. Dendronized acrylates based on 2,2-bis(hydroxymethyl) propionic acid (bis-MPA) were synthesized using dendrimer synthesis and click chemistry (copper catalyzed azide alkyne cycloaddition (CuAAC)). The synthesis was carried out up to the 3rd generation and with a carbon spacer length of 6 or 9 between the acrylic function and the dendron core. These dendronized acrylates were subjected to auto-initiated high temperature acrylate polymerization. The polymerization was performed at 140 degrees C in a 5 wt% solution of hexyl acetate with a 2,2'-azobis(isobutyronitrile) (AIBN) concentration of 5 x 10(-3) g mol(-1). The vinyl terminated polymers were in-depth characterized via size exclusion chromatography (SEC) and size exclusion chromatography coupled to electrospray ionization mass spectrometry (SEC-ESI-MS) to assess the generated product spectrum and the efficiency of the process. The achievable number average molecular weight, M-n, was between 1700 and 4400 g mol(-1). The degree of polymerization, DPn, decreases with increasing generations of the dendronized acrylates from 6.3 to 3.4. The purity of vinyl terminated oligomers containing a geminal double bond is up to 83%, with the dendronized acrylates of the 1st generation providing the best result. Moderate deprotection of the acetonide groups occurred spontaneously during the macromonomer formation process and reached its maximum at generation 3.

  • 134.
    Öberg, Kim
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hed, Yvonne
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Joelsson Rahmn, Isabella
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Kelly, Jonathan
    Löwenhielm, Peter
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Dual-purpose PEG scaffolds for the preparation of soft and biofunctional hydrogels: the convergence between CuAAC and thiol-ene reactions2013In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 49, no 62, p. 6938-6940Article in journal (Refereed)
    Abstract [en]

    Orthogonally functionalized PEGs displaying alkenes and azides have been prepared and their dual-purpose scaffolding potential was exploited via click chemistry for controlled insertion of bio-relevant moieties as well as facile fabrication of soft, non-toxic and degradable hydrogels.

  • 135.
    Öberg, Kim
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Ropponen, Jarmo
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Kelly, Jonathan
    Löwenhielm, Peter
    Berglin, Mattias
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Templating Gold Surfaces with Function: A Self-Assembled Dendritic Monolayer Methodology Based on Monodisperse Polyester Scaffolds2013In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 29, no 1, p. 456-465Article in journal (Refereed)
    Abstract [en]

    The antibiotic resistance developed among several pathogenic bacterial strains has spurred interest in understanding bacterial adhesion down to a molecular level. Consequently, analytical methods that rely on bioactive and multivalent sensor surfaces are sought to detect and suppress infections. To deliver functional sensor surfaces with an optimized degree of molecular packaging, we explore a library of compact and monodisperse dendritic scaffolds based on the nontoxic 2,2-bis(methylol)propionic acid (bis-MPA). A self-assembled dendritic monolayer (SADM) methodology to gold surfaces capitalizes on the design of aqueous soluble dendritic structures that bear sulfur-containing core functionalities. The nature of sulfur (either disulfide or thiol), the size of the dendritic framework (generation 1-3), the distance between the sulfur and the dendritic wedge (4 or 14 angstrom), and the type of functional end group (hydroxyl or mannose) were key structural elements that were identified to affect the packaging densities assembled on the surfaces. Both surface plasmon resonance (SPR) and resonance-enhanced surface impedance (RESI) experiments revealed rapid formation of homogenously covered SADMs on gold surfaces. The array of dendritic structures enabled the fabrication of functional gold surfaces displaying molecular covering densities of 0.33-2.2 molecules.nm(-2) and functional availability of 0.95-5.5 groups.nm(-2). The cell scavenging ability of these sensor surfaces for Escherichia coli MS7fim+ bacteria revealed 2.5 times enhanced recognition for G3-mannosylated surfaces when compared to G3-hydroxylated SADM surfaces. This promising methodology delivers functional gold sensor surfaces and represents a facile route for probing surface interactions between multivalently presented motifs and cells in a controlled surface setting.

  • 136.
    Östmark, Emma
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Macakova, Lubica
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Auletta, Tommaso
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Blomberg, Eva
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Dendritic Structures Based on Bis(hydroxymethyl)propionic Acid as Platforms for Surface Reactions2005In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, no 10, p. 4512-4519Article in journal (Refereed)
    Abstract [en]

    In this paper we present results related to the self-assembly of different generations of disulfide-cored 2,2-bis(hydroxymethyl)propionic acid-based dendritic structures onto gold surfaces. These molecular architectures, ranging from generation 1 to generation 3, contain removable acetonide protecting groups at their periphery that are accessible for hydrolysis with subsequent formation of OH-terminated surface-attached dendrons. The deprotection has been investigated in detail as a versatile approach to accomplish reactive surface platforms. A special focus has been devoted to the comparison of the properties of the layers formed by hydrolysis of the acetonide moieties directly on the surface and in solution, prior to the layer formation.

123 101 - 136 of 136
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