Layer-by-layer deposition of insulin on nano-liposomes for loading and stability enhancement

• Main Author: Wee, Shi Ting
• Other Authors: Subbu S. Venkatraman
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/76705
• Institution: Nanyang Technological University

Most diabetic patients require insulin to keep their blood glucose levels in the acceptable range. The most widely used method of delivering insulin into the bloodstream is via subcutaneous insulin injections through vials and syringes, insulin pen and insulin pumps. Although subcutaneous insulin injection is the standard route of insulin administration, it is often associated with a lack of patient compliance due to pain as well as the risk of hypoglycemia (low blood glucose level). As a result, there is a need to explore other suitable alternatives for the delivery of insulin in the most physiological manner with minimal or no invasiveness. Oral drug delivery is one of the possible method for insulin administration as it is the most patient-friendly way of delivering insulin and it also reduces the risk of hypoglycemia as the oral route mimics the natural pathway of insulin delivery in the body. However, there are some obstacles faced in using oral delivery such as the degradation of insulin in the acidic environment of the stomach before it reaches the small intestine and the poor bioavailability of insulin due to its large size and hydrophilicity which leads to low permeability through the intestinal membrane. As such, the purpose of this research aims to resolve these obstacles faced through layer-by-layer deposition of insulin onto nanosized liposomes. Alternative layers of chitosan and insulin were achieved using the electrostatic attractive forces between the two oppositely-charged polyelectrolytes. Through optimization of the chitosan and insulin layers, ideal particle sizes and surface charges were achieved. Particle sizes, PDI and zeta potential can be obtained through characterization of the alternate layers via DLS (Dynamic Light Scattering) measurements with the use of the Zetasizer Nano. Chitosan of three different molecular weight were used to study the effect of polymer chain length and molecular weight on the particle properties and release behavior. The aim of this research is to study the feasibility of the potential layer-by-layer assembly of nano-liposomes as means of delivering insulin orally.