Amphiphilic linear-dendritic block copolymers for drug delivery

Polymeric drug delivery systems have been widely used in the pharmaceutical industry. Such systems can solubilize and sequester hydrophobic drugs from degradation, thereby increasing circulation half-life and efficacy. However, there are still challenges in the design of drug delivery vehicles to achieve efficient drug delivery in a site-specific manner. In this thesis, an amphiphilic linear-dendritic block copolymer was designed, synthesized, and applied as a new polymeric drug delivery platform. First, to develop the drug delivery vehicle, an ABA dendritic-linear-dendritic block copolymer consisting of poly(amidoamine) (PAMAM) and poly(propylene oxide) (PPO) was synthesized. In order to determine the viability of the linear-dendritic block copolymer as a drug delivery vehicle, the solution-phase self-assembly behavior and the self-assembled structures were characterized experimentally and through molecular dynamics simulations. The triblock self-assembles in aqueous media to form stable micelles with low CMC values. Dynamic light scattering results and TEM indicate the formation of particles ranging from 9 to 18 nm in diameter, with smaller diameters exhibited at higher generations. Static light scattering also confirmed the trend where the aggregation number decreased with higher generations. The experimental characterization results indicated that the physical characteristics of the PPO-PAMAM micelles were desirable and within the design specifications necessary for drug delivery. The experimental results were utilized to set up simulations where further knowledge of the microstructure of the micelles formed could be gained. It was found that the block copolymers simulated formed micelles in the same size range that was seen experimentally. However, the simulations indicated that the micelles displayed greater asphericity than dendrimers.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Nguyen, Phuong, Ph. D. Massachusetts Institute of Technology

Advisor dc:contributor.advisor

• Paula T. Hammond and Robert Langer.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/42432

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/42432