Electroresponsive conducting nanoparticles for drug delivery
Abstract/Contents
- Abstract
- Conducting polymers are organic polymers that can change their shape and size in response to an external electric stimulus. These polymers are promising for developing programmable, adjustable, spatially and temporally controllable drug delivery systems (DDSs). Drug release is evoked by application of weak voltages or currents. However, several limitations including (i) low drug loading, (ii) incompatibility with electroactive drugs, and (iii) difficulty of scale up have made thin conducting films refractory to clinical development. To overcome these difficulties, we have utilized nanoparticles of conducting polypyrrole (PPy NPs) to design a versatile DDS capable of releasing a variety of both small and large molecule therapeutics. As examples, we have shown facile release of fluorescein, a hydrophilic model compound, piroxicam, a hydrophobic small molecule used in the management of chronic arthritic pain, methotrexate, an anti-cancer drug, and insulin, a hydrophilic polypeptide used in the treatment of diabetes. The use of nanoparticles allows easy scale up and substantially increased drug loading, estimated to be as high as 51 wt%. Moreover, by modifying the synthesis and incorporating metallic elements into the polymer scaffold, it is possible to release drugs at voltages as low as - 0.05 V vs Ag/AgCl, almost an order of magnitude lower than typically used voltages for thin films. This widens the window of operating voltage and allows PPy NPs to be used in the delivery of redox sensitive drugs. Moreover, we have demonstrated that PPy NPs can be used as a generalized pH-sensitive drug delivery system, capable of releasing any charged drug preferentially at the pH range of interest. They can be tuned to release drugs at both acidic and basic pH by varying the acidity, the charge of the drug, as well as by adding small amounts of charged amphiphiles. These PPy NPs may be delivered locally by immobilizing them in a hydrogel or coupling them to an implantable chip. We have performed proof-of-principle studies demonstrating that the drug release can be triggered wirelessly. Our results demonstrate the potential of using conducting polymer nanoparticles to treat long lasting conditions such as chronic pain, diabetes and cancer by developing externally controlled, programmable implants.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2017 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Samanta, Devleena |
|---|---|
| Associated with | Stanford University, Department of Chemistry. |
| Primary advisor | Zare, Richard N |
| Thesis advisor | Zare, Richard N |
| Thesis advisor | Cegelski, Lynette |
| Thesis advisor | Fayer, Michael D |
| Advisor | Cegelski, Lynette |
| Advisor | Fayer, Michael D |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Devleena Samanta. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2017. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2017 by Devleena Samanta
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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