Controlled release of doxorubicin from pH-responsive microgels

Mahrokh Dadsetan, K. Efua Taylor, Chun Yong, Željko Bajzer, Lichun Lu, Michael J. Yaszemski

Research output: Contribution to journalArticlepeer-review

62 Scopus citations


Stimuli-responsive hydrogels have enormous potential in drug delivery applications. They can be used for site-specific drug delivery due to environmental variables in the body such as pH and temperature. In this study, we have developed pH-responsive microgels for the delivery of doxorubicin (DOX) in order to optimize its anti-tumor activity while minimizing its systemic toxicity. We used a copolymer of oligo(polyethylene glycol) fumarate (OPF) and sodium methacrylate (SMA) to fabricate the pH-responsive microgels. We demonstrated that the microgels were negatively charged, and the amounts of charge on the microgels were correlated with the SMA concentration in their formulation. The resulting microgels exhibited sensitivity to the pH and ionic strength of the surrounding environment. We demonstrated that DOX was efficiently loaded into the microgels and released in a controlled fashion via an ion-exchange mechanism. Our data revealed that the DOX release was influenced by the pH and ionic strength of the solution. Moreover, we designed a phenomenological mathematical model, based on a stretched exponential function, to quantitatively analyze the cumulative release of DOX. We found a linear correlation between the maximum release of DOX calculated from the model and the SMA concentration in the microgel formulation. The anti-tumor activity of the released DOX was assessed using a human chordoma cell line. Our data revealed that OPF-SMA microgels prolonged the cell killing effect of DOX.

Original languageEnglish (US)
Pages (from-to)5438-5446
Number of pages9
JournalActa Biomaterialia
Issue number3
StatePublished - Mar 2013


  • Chordoma
  • Doxorubicin
  • Microgels
  • Oligo(polyethylene glycol) fumarate
  • pH-responsive

ASJC Scopus subject areas

  • Biotechnology
  • Biomaterials
  • Biochemistry
  • Biomedical Engineering
  • Molecular Biology


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