Lipophilic drugs encapsulation in gradient format for tissue engineering applications

• Main Author: Teo, Albert Gui Xiong.
• Other Authors: Chew Sing Yian
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Chemical engineering::Biotechnology
• Online Access: http://hdl.handle.net/10356/16454
• Institution: Nanyang Technological University

In tissue engineering, manipulating the controlled release of a lipophilic drug in gradient format can control the rate of cell chemotaxis, which might play a role in treating or alleviating injuries or diseases. One challenge is to create a biomaterial that is able to hold the drug over extended period of time without being rejected by the body, or releasing chemicals which might be toxic. The aim of this study is to study the release profile of an encapsulated lipophilic drug subjected to a concentration gradient. PCL will be the material of choice used to encapsulate retinoic acid, and to realize this, co-axial electrospinning will be utilized. The first part of this study involves the successful optimization of the PCL fibers to yield fibers which have uniform size distribution and desirable morphology. The incorporation of PEG into PCL, and the subsequent optimization of the PEG/PCL fibers act as a control in subsequent controlled release study. The second part of the study will involve the calibration of varying concentration of retinoic acid over absorbance using spectrophotometry. The tendency of retinoic acid to degrade when exposed to air and aqueous medium at ambient conditions over time poses a challenge, and although no consistent correlation exists for each concentration calibrated, the information obtained shall be used in the controlled release study to give a semi-quantitative result. Finally, the encapsulated scaffolds are weighed and used for controlled release studies. Results show that the existence of a concentration gradient extends the release of the encapsulated retinoic acid, while the addition of PEG speeds up its release.