Characterization of an Encapsulation Platform for pH-sensitive Delivery to the Colon
| dc.contributor.author | Miller, Madison | |
| dc.contributor.supervisor | Hoorfar, Mina | |
| dc.date.accessioned | 2023-10-24T22:52:20Z | |
| dc.date.available | 2023-10-24T22:52:20Z | |
| dc.date.copyright | 2023 | en_US |
| dc.date.issued | 2023-10-24 | |
| dc.degree.department | Department of Mechanical Engineering | en_US |
| dc.degree.level | Master of Applied Science M.A.Sc. | en_US |
| dc.description.abstract | Targeted delivery of bioactive molecules to specific locations within the GI tract allows for better orally delivered therapies, as the molecules will only be released upon reaching the desired absorption or delivery location. Targeted delivery aids in protecting the bioactivity of sensitive cargo as it traverses the GI tract, allows for smaller dosages to be administered and, in some cases, can reduce side effects. In this study, a microfluidic droplet generation platform is designed for production of pH-sensitive microcapsules for targeted delivery of bioactive molecules to the colon. Optical microscopy is used to compare the size distributions of microcapsules generated on-chip and those generated through a simple bulk double emulsion. Scanning electron microscopy is used to characterize the microcapsule morphology. To test the pH-sensitive nature of the microcapsules, they are loaded with dyed microparticles to mimic micron-sized bioactive cargo being interlocked in the polymeric capsule matrix. Their release in acidic and neutral solution is then analyzed, to simulate exposure to the stomach and colon. A preliminary study is then completed using E. coli DH5 alpha as the capsule payload. Results show that a maximum of 7.8 ± 2.0% of the encapsulated microparticles are released in acidic medium, while a maximum of 70.7 ± 3.7% are released in neutral solution after 6 hours of exposure, thus confirming the pH-sensitive characteristics of the microcapsules (based on results across 3 trials). Finally, capsules were loaded with E. coli and exposed to both neutral and acidic solution. After 6 hours, 0 viable CFU/ml were recorded, and in neutralsolution5.56x106 ±0.9x106,2.6x107 ±1.8x106 and2.2x108 ±2.4x107 CFU/ml were released across 3 trials, corresponding to a maximum viability of 1.37 ± 0.15%. These results were supported by a zeta potential study, which also showed targeted release in neutral solution, and minimal change in zeta potential for capsules in acidic solution. Although these results support the pH-sensitive properties of the microcapsules, they indicate incompatibility of the platform with live cargo. Future work for this study includes testing the capsules with other bioactive cargo, such as vitamins, minerals, and pharmaceuticals, and altering the capsule structure for better compatibility with live bacteria. | en_US |
| dc.description.scholarlevel | Graduate | en_US |
| dc.identifier.uri | http://hdl.handle.net/1828/15550 | |
| dc.language | English | eng |
| dc.language.iso | en | en_US |
| dc.rights | Available to the World Wide Web | en_US |
| dc.subject | Microfluidics | en_US |
| dc.subject | Encapsulation | en_US |
| dc.subject | Targeted delivery | en_US |
| dc.subject | Oral drug delivery | en_US |
| dc.title | Characterization of an Encapsulation Platform for pH-sensitive Delivery to the Colon | en_US |
| dc.type | Thesis | en_US |