Stimuli-Responsive Microgel-Based Systems and Their Application for Controlled Drug Release

• Author / Creator

  Gao, Yongfeng

• Stimuli-responsive polymers have found their way into numerous materials and devices for myriad applications that can solve problems related to human health and the environment. In this dissertation, the work covers the general scope of stimuli-responsive polymers, with a special focus on thermo-responsive poly (N-isopropylacrylamide) (pNIPAm)-based microgels and their co-functional composites, and their applications in controlled drug delivery. Chapter 1 gives a brief introduction about stimuli-responsive polymers and Chapter 2 discusses the applications of stimuli-responsive polymers in controlled drug delivery. In Chapter 3, the study of rate control, by varying the thickness of a membrane (device Au layer) was shown to control the rate of release from the device. With the increase of Au layer thickness, the drug release rate is able to slow down and the release could be triggered by temperature and pH. After that, the modification of the devices membrane layer was investigated for its ability to control the release behavior (Chapter 4). Subsequently, a multi-drug releasing system was developed by incorporating two different microgels, which has the ability to sequential release drugs by changing the pH (Chapter 5). Free-standing assemblies of microgels were then generated by simply applying a sacrificial layer under the film and this film was transferable to other substrates, whether flat or curve surface, and even human skin (Chapter 6). In Chapter 7, the optical properties and drug releasing behavior were studied on this developed device by light-induced pH change, which makes this platform versatile for developing smart systems based on other stimuli. Furthermore, by tuning the chemistry of microgels, we were able to generate microgel-based aggregates for drug delivery applications from microgels with opposite charges (Chapter 8). In Chapter 9, novel microgels from supramolecular crosslinker were firstly prepared with the degradable properties. The characterizations of this microgel promote it as a great candidate for degradable drug delivery system. Finally, in Chapter 10, conclusion and future outlook are presented to illustrate the future direction of this research topic.

• Subjects / Keywords

  • Stimuli-responsive polymer
  • Controlled drug delivery
  • Microgels

• Graduation date

  Fall 2017

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3T14V555

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.