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Ahrenstedt, L., Hed, Y., Hult, A., Zilla, P., Bezuidenhout, D. & Malkoch, M. (2024). Sustained zero-order release of dexamethasone after incorporation into crosslinked PEG-dendrons using click reactions. Journal of Drug Delivery Science and Technology, 95, Article ID 105637.
Open this publication in new window or tab >>Sustained zero-order release of dexamethasone after incorporation into crosslinked PEG-dendrons using click reactions
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2024 (English)In: Journal of Drug Delivery Science and Technology, ISSN 1773-2247, Vol. 95, article id 105637Article in journal (Refereed) Published
Abstract [en]

Hydrogel-based localised drug delivery minimises systemic side effects and a linear release profile ensuring a sustained drug release over time, crucial for long-term therapy. The current paper describes the use of the Copper(I)-catalyzed Azide-Alkyne Cycloaddition (CuAAc) to append azidified Dexamethasone (Dex) onto dendrons of first- and second-generation PEGs. Crosslinking with thiolated PEGs using either thiol-acrylate or nucleophilic addition reactions yielded gels containing β-thio-ether ester groups that imparted enhanced hydrolytic susceptibility. In vitro gel degradation was followed gravimetrically and expressed as swelling ratios. Thiol-acrylate crosslinked hydrogels exhibited zero-order Dex release kinetics over 11, 27, and 16 days (G1, G1-star, and G2). Crosslinking the G1-gels by nucleophilic addition also resulted in linear release and the end point was reached in 5 days. Hydrolysis was accounted as the main release mechanism for covalently bound Dex, while physically incorporated Dex showed undefined rapid burst or first-order release, with most of the drug released in the initial 1–3 days. Eluates from covalently bound Dex maintained high activity, whereas Trap-Dex gels lost activity over time, as detected by the upregulation of luciferase expression from a transformed cell line. This novel chemistry combination offers precise drug release control applicable beyond Dex to drugs with suitable nucleophilic groups.

Place, publisher, year, edition, pages
Elsevier BV, 2024
National Category
Pharmaceutical Sciences
Identifiers
urn:nbn:se:kth:diva-345757 (URN)10.1016/j.jddst.2024.105637 (DOI)001225572200001 ()2-s2.0-85189810726 (Scopus ID)
Note

QC 20240603

Available from: 2024-04-18 Created: 2024-04-18 Last updated: 2024-06-03Bibliographically approved
Santos, E. C., Kaldéus, T., Senoro, D. B., Malmström, E. & Hult, A. (2020). Current Cellulose Nanofibrils and Cellulose Nanocrystals as Water Purification Functional Membrane Materials. Journal of Environmental Science and Management, 23(SI 1), 48-64
Open this publication in new window or tab >>Current Cellulose Nanofibrils and Cellulose Nanocrystals as Water Purification Functional Membrane Materials
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2020 (English)In: Journal of Environmental Science and Management, ISSN 0119-1144, Vol. 23, no SI 1, p. 48-64Article in journal (Refereed) Published
Abstract [en]

This study highlights the beneficial role of cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) as components in functional membranes. The approaches of the use of CNF and CNC as membrane materials Ibr water purification have been studied extensively during the past decades. This is due to their inherent abundance, renewability, sustainability and unique properties such as high aspect ratio, high surface area, high crystallinity, and high mechanical properties. The performance of CNF- and CNC-based membranes especially in treating actual water samples were also highlighted in this review to give a better overview of the behavior of these nanocellulose as membrane materials. The challenges of using CNFs and CNCs and the needfor improvements for the future development of membrane materials are also discussed.

Place, publisher, year, edition, pages
School of Environmental Science and Management, University of the Philippines Los Banos, 2020
Keywords
bamboo cellulose, membrane, nanocrystals, nanofibrils, water purification
National Category
Bio Materials
Identifiers
urn:nbn:se:kth:diva-289918 (URN)10.47125/jesam/2020_sp1/06 (DOI)000607449600006 ()2-s2.0-85100536449 (Scopus ID)
Note

QC 20250314

Available from: 2021-02-11 Created: 2021-02-11 Last updated: 2025-03-14Bibliographically approved
Olofsson, K., Granskog, V., Cai, Y., Hult, A. & Malkoch, M. (2016). Activated dopamine derivatives as primers for adhesive-patch fixation of bone fractures. RSC Advances, 6(31), 26398-26405
Open this publication in new window or tab >>Activated dopamine derivatives as primers for adhesive-patch fixation of bone fractures
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2016 (English)In: RSC Advances, E-ISSN 2046-2069, Vol. 6, no 31, p. 26398-26405Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2016
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-185678 (URN)10.1039/c5ra23142f (DOI)000372812300090 ()2-s2.0-84961191443 (Scopus ID)
Note

QC 20160425

Available from: 2016-04-25 Created: 2016-04-25 Last updated: 2024-03-18Bibliographically approved
Olofsson, K., Malkoch, M. & Hult, A. (2016). Facile Synthesis of Dopa-Functional Polycarbonates viaThiol-Ene-Coupling Chemistry towards Self-Healing Gels. Journal of Polymer Science Part A: Polymer Chemistry, 54(15), 2370-2378
Open this publication in new window or tab >>Facile Synthesis of Dopa-Functional Polycarbonates viaThiol-Ene-Coupling Chemistry towards Self-Healing Gels
2016 (English)In: 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) Published
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.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2016
Keywords
Dopa, Photochemistry, Post-polymerization functionalization, Ring-opening-polymerization, Synthetic methods, Thiol-ene coupling
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-180887 (URN)10.1002/pola.28111 (DOI)000381302400013 ()2-s2.0-84978016931 (Scopus ID)
Note

QC 20161103

Available from: 2016-01-25 Created: 2016-01-25 Last updated: 2022-06-23Bibliographically approved
Mongkhontreerat, S., Walter, M. V., Cai, Y., Brismar, H., Hulta, A. & Malkoch, M. (2015). Functional porous membranes from amorphous linear dendritic polyester hybrids. Polymer Chemistry, 6(13), 2390-2395
Open this publication in new window or tab >>Functional porous membranes from amorphous linear dendritic polyester hybrids
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2015 (English)In: Polymer Chemistry, ISSN 1759-9954, E-ISSN 1759-9962, Vol. 6, no 13, p. 2390-2395Article in journal (Refereed) Published
Abstract [en]

By combining ATRP, dendrimer chemistry and 'click' reactions, a library of novel linear dendritic block copolymers (hybrids) was successfully synthesized. The isolated polymers displayed hydrophilic alkyne groups and T-g's ranging from 14 degrees C to 67 degrees C. A T-g threshold of 39 degrees C was found necessary for straightforward porous membrane fabrication via the breath figure method. Exploiting the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, a robust and benign protocol was identified enabling surface functionalization under aqueous conditions. Such manipulations included the introduction of fluorescent rhodamine for thorough assessment by confocal fluorescence microscopy as well as polyethylene glycol chains or perfluorinated groups for tuning the membrane wettability. Finally, with the initial indication of being nontoxic to human dermal fibroblasts (hDF) and osteoblast-like MG63, the porous membranes can potentially find use in the field of controlled cell culture such as patterning of cell growth.

National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-164488 (URN)10.1039/c4py01803f (DOI)000351493500004 ()2-s2.0-84925004535 (Scopus ID)
Note

QC 20150420

Available from: 2015-04-20 Created: 2015-04-17 Last updated: 2022-06-23Bibliographically approved
Yamaguchi, S., Tanha, M., Hult, A., Okuda, T., Ohara, H. & Kobayashi, S. (2014). Green polymer chemistry: lipase-catalyzed synthesis of bio-based reactive polyesters employing itaconic anhydride as a renewable monomer. Polymer journal, 46(1), 2-13
Open this publication in new window or tab >>Green polymer chemistry: lipase-catalyzed synthesis of bio-based reactive polyesters employing itaconic anhydride as a renewable monomer
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2014 (English)In: Polymer journal, ISSN 0032-3896, E-ISSN 1349-0540, Vol. 46, no 1, p. 2-13Article in journal (Refereed) Published
Abstract [en]

Itaconic acid is a platform compound for bio-based renewable materials. This study employs itaconic anhydride (IAn) as a novel monomer for lipase-catalyzed ring-opening addition condensation polymerization (ROACP) involving dehydration to produce reactive polyesters. ROACP reactions were conducted by combining a cyclic anhydride and a diol. IAn, succinic anhydride (SAn) and glutaric anhydride (GAn) were used as the cyclic anhydrides, and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol and 1,10-decanediol were used as the diols. ROACP between two monomers, IAn and a diol, did not occur. Model reactions using IAn and n-octyl alcohol provided useful information about the regioselectivity and substrate selectivity of IAn. ROACP using three monomer components, IAn, SAn or GAn, and a diol, produced polyesters in good-to-high yields. From the SAn reactions, polyesters with M-n values of 650-3510 with 1.3-2.6 IAn units per molecule were obtained. From the GAn reactions, these values were 560-3690 and 1.2-3.1, respectively. The crosslinking reaction of a product polyester showed its reactive nature, giving a crosslinked hard solid polyester. The present polyesters derived from renewable starting materials have potential applications as macromonomers, telechelics, or crosslinking reagents, and the benign character of the ROACP reaction makes it appropriate for green polymer chemistry.

Keywords
bio-based polymer, green polymer chemistry, itaconic anhydride, lipase, reactive polyester
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-140670 (URN)10.1038/pj.2013.62 (DOI)000329151800002 ()2-s2.0-84891751492 (Scopus ID)
Note

QC 20140130

Available from: 2014-01-30 Created: 2014-01-30 Last updated: 2022-06-23Bibliographically approved
Olofsson, K., Malkoch, M. & Hult, A. (2014). PEG-based hydrogels with well-defined network structures via UV-induced thiol-ene coupling: Synthesis and characterization. Paper presented at 248th National Meeting of the American-Chemical-Society (ACS), AUG 10-14, 2014, San Francisco, CA. Abstracts of Papers of the American Chemical Society, 248
Open this publication in new window or tab >>PEG-based hydrogels with well-defined network structures via UV-induced thiol-ene coupling: Synthesis and characterization
2014 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 248Article in journal, Meeting abstract (Other academic) Published
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-161999 (URN)000349167405089 ()
Conference
248th National Meeting of the American-Chemical-Society (ACS), AUG 10-14, 2014, San Francisco, CA
Note

QC 20150330

Available from: 2015-03-30 Created: 2015-03-20 Last updated: 2022-06-23Bibliographically approved
Olofsson, K., Malkoch, M. & Hult, A. (2014). Soft hydrogels from tetra-functional PEGs using UV-induced thiol-ene coupling chemistry: a structure-to-property study. RSC Advances, 4(57), 30118-30128
Open this publication in new window or tab >>Soft hydrogels from tetra-functional PEGs using UV-induced thiol-ene coupling chemistry: a structure-to-property study
2014 (English)In: RSC Advances, E-ISSN 2046-2069, Vol. 4, no 57, p. 30118-30128Article in journal (Refereed) Published
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.

National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-150946 (URN)10.1039/c4ra04335a (DOI)000340497600022 ()2-s2.0-84904438439 (Scopus ID)
Note

QC 20140911

Available from: 2014-09-11 Created: 2014-09-11 Last updated: 2022-09-15Bibliographically approved
Walter, M. V., Lundberg, P., Hult, D., Hult, A. & Malkoch, M. (2013). A one component methodology for the fabrication of honeycomb films from biocompatible amphiphilic block copolymer hybrids: a linear-dendritic-linear twist. Polymer Chemistry, 4(9), 2680-2690
Open this publication in new window or tab >>A one component methodology for the fabrication of honeycomb films from biocompatible amphiphilic block copolymer hybrids: a linear-dendritic-linear twist
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2013 (English)In: Polymer Chemistry, ISSN 1759-9954, Vol. 4, no 9, p. 2680-2690Article in journal (Refereed) Published
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.

Keywords
Porous Polymer-Films, Water-Assisted Formation, Breath Figures, Morphology Control, Microporous Films, Membranes, Patterns, Adhesion, Growth, Cells
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-119933 (URN)10.1039/C3PY00053B (DOI)000316965200007 ()2-s2.0-84875818911 (Scopus ID)
Funder
Swedish Research Council, 2011-4477 2010-453
Note

QC 20130514

Available from: 2013-03-26 Created: 2013-03-26 Last updated: 2022-06-24Bibliographically approved
Andrén, O. C. J., Walter, M. V., Yang, T., Hult, A. & Malkoch, M. (2013). Multifunctional Poly(ethylene glycol): Synthesis, Characterization, and Potential Applications of Dendritic-Linear-Dendritic Block Copolymer Hybrids. Macromolecules, 46(10), 3726-3736
Open this publication in new window or tab >>Multifunctional Poly(ethylene glycol): Synthesis, Characterization, and Potential Applications of Dendritic-Linear-Dendritic Block Copolymer Hybrids
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2013 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 46, no 10, p. 3726-3736Article in journal (Refereed) Published
Abstract [en]

Emerging dendritic-linear-dendritic (DLD) hybrids that possess synergetic properties of linear and highly functional branched dendritic polymers are becoming important macromolecular scaffolds in fields ranging from biomedicine to nanotechnology. By exploiting pseudo-one-step polycondensation reactions, a facile and scalable synthetic methodology for the construction of highly functional DLDs has been developed. A library of three sets of DLDs exhibiting a hydrophilic linear PEG core with covalently attached hyperbranched bis-MPA blocks was synthesized up to the seventh generation with 256 reactive peripheral hydroxyl groups. The degree of branching for the hybrids was found between 0.40 and 0.59 with dispersities ranging from 1.03 to 1.88. The introduction of hyperbranched components resulted in control over or even full disruption of the crystallinity of the PEG. Postfunctionalizations of the peripheral hydroxyl groups with azides, allyls, and ATRP initiators yielded reactive intermediates. These intermediates were successfully assessed through UV-initiated thiol-ene coupling reactions for the synthesis of charged hybrids. ATRP of styrene from the pheriphery afforded amphiphilic macromolecules. Finally, their scaffolding capacity was evaluated for the fabrication of 3D networks, i.e, novel dendritic hydrogels and highly ordered breath figures.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2013
Keywords
Amphiphilic macromolecules, Degree of branching, Macromolecular scaffolds, Peripheral hydroxyl, Polycondensation reactions, Reactive intermediate, Synergetic properties, Synthetic methodology
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-124987 (URN)10.1021/ma4003984 (DOI)000319795800004 ()2-s2.0-84878266827 (Scopus ID)
Funder
Vinnova, 2012-01252Swedish Research Council, 2011-4477 897 2010-453
Note

QC 20130806

Available from: 2013-08-06 Created: 2013-08-02 Last updated: 2024-03-18Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-9372-0829

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