Colloid and Polymer Science

, Volume 293, Issue 12, pp 3611–3622 | Cite as

Synthesis and characterization of a pH-responsive poly(ethylene glycol)-based hydrogel: acid degradation, equilibrium swelling, and absorption kinetic characteristics

  • Ernandes T. Tenório-Neto
  • Marcos R. Guilherme
  • Michele K. Lima-Tenório
  • Débora B. Scariot
  • Celso V. Nakamura
  • Adley F. Rubira
  • Marcos H. Kunita
Original Contribution


We developed a pH-responsive, hydrogel based on poly(ethylene glycol) (PEG) covalently cross-linked with acrylic acid and N′,N′-dimethylacrylamide along with acid-labile groups. In the hydrogel, PEG plays a role as the key constituent. If its chains break, the polymer networks are destroyed. The pharmacological potential of these hydrogels were demonstrated by determining their water transport profile, modulus of elasticity, and cytotoxicity assay. The hydrogels showed a pseudo-Fickian behavior, a transport mechanism that occurs when the diffusion coefficient changes with the time and the swelling equilibrium is never fully reached. At pH 2, the PEG-richer hydrogels degraded and the scanning electron microscopy (SEM) images illustrated less-defined shapes than at pH 7 and 10. This morphological characteristic results of the hydrogel deconstruction owing to cleavage of ether bonds of the PEG chains unmaking its 3D polymer network. The proposed hydrogels were shown to be compatible to cells, indicating acceptable biocompatibility and an appropriate level of security for use in the biological environments. Furthermore, they showed structural changes in their polymer network in response to pH, which is an important characteristic for stimuli-triggered release of guest molecules.


Smart polymers Hydrogel PEG pH responsiveness Polymer gels Water transport 



E. T. T. N. and M. K. L. T. are grateful to the Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior (CAPES) for a doctorate fellowship. M. R. G. thanks the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for post-doctorate fellowship (proc. no. 167432/2013-3). A. F. R. and M. H. K. acknowledge the financial supports given by CNPq, CAPES, Instituto de Ciência, Tecnologia e Inovação em Materiais Complexos e Funcionais (INOMAT), and Fundação Araucáia-Brasil.


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© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Ernandes T. Tenório-Neto
    • 1
  • Marcos R. Guilherme
    • 1
  • Michele K. Lima-Tenório
    • 1
  • Débora B. Scariot
    • 2
  • Celso V. Nakamura
    • 2
  • Adley F. Rubira
    • 1
  • Marcos H. Kunita
    • 1
  1. 1.Department of ChemistryState University of MaringáMaringáBrazil
  2. 2.Department of Basic Sciences of HealthState University of MaringáMaringáBrazil

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