Stimuli-responsive drug delivery systems using gold nanoparticles and phospholipid vesicles

Abstract

In the near future, new pharmaceutical therapeutics will evolve to contain complicated protein molecules, gene therapies, SI-RNA etc., which must be transported in extremely specific environments such as a specific pH level or sodium concentration. The problem is that throughout the body there are many different environments that a drug could pass through. For example, gastric acid can have pH levels as low as 1 where blood is around 7.4. This is a problem because as the drugs pass through these harsh environments they may become rendered useless. Furthermore, these new therapeutics are not compatible with conventional drug delivery mechanisms and new strategies for drug delivery are required. To solve these problem DPPC/DPPG phospholipid vesicles are being used with Au nanoparticles to transport these drugs. The DPPC/DPPG vesicles encapsulate the drug of choice and protect it from the harsh environments of the body. The Au nanoparticles can be designed to either embedded in the lipid bilayer of the vesicles or decorate the vesicle exterior. When radiation is applied, the nanoparticles are excited and cause a disruption in the vesicle structure, leading to the release of the drug into the body. Our research is centered around how the stability of the lipid vesicles changes based on the size, surface chemistry, and distribution of the nanoparticles.