Change search
ReferencesLink to record
Permanent link

Direct link
Versatile Functionalization of Polyester Hydrogels with Electroactive Aniline Oligomers
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.ORCID iD: 0000-0002-1922-128X
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
2011 (English)In: Journal of Polymer Science Part A: Polymer Chemistry, ISSN 0887-624X, E-ISSN 1099-0518, Vol. 49, no 9, 2097-2105 p.Article in journal (Refereed) Published
Abstract [en]

Functionalizing aliphatic polyester hydrogels with an aniline oligomer is a means of achieving electrically conductive and degradable hydrogels. To lower the aniline oligomer content while maintaining a high conductivity and to overcome the acidic degradation product from polylactide reported in our previous work, a series of electroactive and degradable hydrogels based on polycaprolactone (PCL) hydrogels and carboxyl-capped aniline pentamer (CCAP) were synthesized by a simple coupling reaction at room temperature. The reaction was carried out between the hydroxyl groups of hydroxyethylmethacrylate in a photopolymerized glycidyl methacrylate (GMA)-functionalized PCL-poly(ethylene glycol)-PCL degradable network and carboxyl group of CCAP, using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as water-condensing agent and 4-dimethylamino-pyridine as catalyst. The electroactivity of the hydrogels was verified by cyclic voltammetry, which showed three pairs of redox peaks. The electrical conductivities and swelling ratios of these hydrogels were controlled by the CCAP content, the poly(ethylene glycol) molecular weight in the macromer, and the crosslinking density of the hydrogels.

Place, publisher, year, edition, pages
2011. Vol. 49, no 9, 2097-2105 p.
Keyword [en]
aniline pentamer, biodegradable hydrogel, biodegradable, conducting hydrogels, conducting polymers, electroactive and degradable polymer, functionalization of polymers, functionalization, hydrogels
National Category
Polymer Chemistry
URN: urn:nbn:se:kth:diva-32616DOI: 10.1002/pola.24643ISI: 000288966600019ScopusID: 2-s2.0-79953061850OAI: diva2:411724
Swedish Research Council, 2008-5538
QC 20110419Available from: 2011-04-19 Created: 2011-04-18 Last updated: 2011-11-23Bibliographically approved
In thesis
1. degradable electroactive polymers: Synthesis, Macromolecular architecture and scaffold design
Open this publication in new window or tab >>degradable electroactive polymers: Synthesis, Macromolecular architecture and scaffold design
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Electrically conducting polymers induce specific cellular responses at the molecular level. One of the crucial limitations of the use of conducting polymers in tissue engineering is their inability to degrade. The incorporation of conductivity into degradable polymers to obtain materials that are both electroactive and degradable is therefore highly anticipated. Architecture plays an important role in the performance of polymers. To be able to achieve the optimal mechanical, degradation, thermal and biological properties for a particular biomedical application, it is desirable to promote architectural diversity.

 In the first part, by combining the electroactivity of conducting polymers and the degradability of aliphatic polyesters, we have designed and synthesized a series of linear, star-shaped, hyperbranched, and crosslinked degradable and electrically conducting polymers and hydrogels based on polylactide (PLA), polycaprolactone (PCL), and aniline oligomers such as aniline trimer, aniline tetramer, and aniline pentamer. The polymers and hydrogels obtained have good electroactivity, as indicated by their ultraviolet spectra and by cyclic voltammetry. The conductivities of the polymers and hydrogels are tuned by the content of the aniline oligomer and the macromolecular architecture. The hydrophilicity of the polymers was greatly increased after doping the aniline oligomer with acid, which overcomes the hydrophobicity of the PLA and PCL. Thermogravimetric analysis and differential scanning calorimetry studies show that these copolymers and hydrogels have good thermal properties compared to PLA and PCL. The swelling ratios of these hydrogels covered a wide range and were controlled by the degree of crosslinking, the oligoaniline content, and the pH of the surrounding solution.

 In the next part, methods for the facile synthesis of degradable conducting polymers and hydrogels were presented to avoid the multi-step reaction used in the earlier work. We developed a one-pot reaction for the synthesis of degradable conducting polysaccharide hydrogels based on chitosan and aniline tetramer. These hydrogels can form free-standing and flexible conducting films. This overcomes the drawback of polyaniline which could not be easily fabricated into a thin film in common organic solvents. We also presented a universal two-step approach to create degradable conductive diblock or triblock copolymers based on a polyester and aniline tetramer or aniline pentamer by a combination of ring opening polymerization and post-functionalization via an oxidative coupling reaction. The self-assembly behavior of the triblock copolymer consisting of a middle aniline pentamer segment and two bilateral polycaprolactone segments in chloroform as a selective solvent (selective for PCL segment) were also investigated by transmission electron microscopy and dynamic light scattering. The size of the nanoparticles from the assembly of the triblock copolymers depends on the molecular weight of the copolymer and on the aniline pentamer state.

 In the last part, electroactive degradable non-toxic porous tubular scaffolds were fabricated from a polymer blend of hyperbranched degradable conductive copolymer and PCL by a modified solution-casting/particle-leaching technique. The porous structure of the tubular scaffolds was investigated by scanning electron microscope and microcomputed tomography. The hydrophilicity of the blend films was greatly improved by doping with (±)-10-camphorsulfonic acid. The conductivity of the films was tuned by adjusting the ratio of hyperbranched degradable conducting copolymer to PCL. The cytotoxicity test with HaCaT keratinocytes indicated that the materials were non-toxic.

 These degradable electroactive copolymers and hydrogels with different architectures and properties have a great potential for meeting the requirements of biomedical application.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2011. 87 p.
Trita-CHE-Report, ISSN 1654-1081 ; 2011:55
Poly(lactide), poly(ε-caprolactone), ring-opening polymerization, carboxyl-capped aniline trimer, carboxyl-capped aniline pentamer, phenyl amino-capped aniline tetramer, coupling reaction, DCC/DMAP system, degradability, electroactivity, conductivity, macromolecular architecture, chitosan, hydrogel, block copolymer, functionalization, oxidative coupling reaction, self-assembly, toxicity, tubular porous scaffold, neural tissue engineering.
National Category
Engineering and Technology
urn:nbn:se:kth:diva-48171 (URN)978-91-7501-136-3 (ISBN)
Public defence
2011-12-07, F3, Lindstedsvägen 26, KTH,, Stockholm, 10:00 (English)
QC 20111123Available from: 2011-11-23 Created: 2011-11-16 Last updated: 2011-11-23Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Guo, BaolinFinne-Wistrand, AnnaAlbertsson, Ann-Christine
By organisation
Polymer Technology
In the same journal
Journal of Polymer Science Part A: Polymer Chemistry
Polymer Chemistry

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 117 hits
ReferencesLink to record
Permanent link

Direct link