PHASE-SEPARATING MICROBUBBLES FUNCTIONING AS VACCINE DEPOTS
Abstract
Failure in receiving a booster for specific vaccines contributes to incomplete
seroconversion, particularly in the developing world. Single injection vaccine
technology could potentially be a solution such that health care personnel would not
need to meet patients multiple times at designated points in time thereafter. The main
challenge for single injection vaccine systems to date is controlling the stability of the
antigen. to maintain the antigenic protein structure while in the physiological
environment. We engineered a novel phase-separating microbubble technology which
could function as an injectable depot which we hypothesize will enable us to control the
microenvironment of the antigen for the durations required, in addition to controlling the
antigen release time.
We have successfully accomplished the following Main Specific Aims and subaims:
Main Specific Aim 1: Synthesize polymers for microbubbles formation and Engineer
methods for stabilizing Microbubbles:
1A: Synthesize PCL and PLGA library at different molecular weights and
characterizing the polymers
1B: Synthesize acrylate polymers for microbubbles
1C: Engineer stable microbubble through UV cure and lyophilization
1D: Engineering the microbubbles to be stationary for maintaining sphere shape during
the curing process and the inject of the cargo
1E: Engineering the cargo to be stationary within the polymeric microbubble to
maximize the release time
1F: Quantify the diameter of the microbubble by varying syringe pump rate and
comparing diameter pre- and post-lyophilization
1G: Quantify the angle of the micromotor for injecting cargo into the center of the
microbubbles
1H: Engineer a self-contained lyophilization-capable system for the microbubbles
Main Specific Aim 2: Engineering cargo release time of the microbubbles:
2A: Quantify how different molecular weights of PCL affect release time of the
microbubbles
2C: Quantify how varying the microbubbles’ thickness of the shell controls the release
time
Main Specific Aim 3: Quantify stability of HIV and Hepatitis B antigens:
3A: Quantify how the HIV gp120/41 and HBsAg ayw antigens are stable in time in an
aqueous environment versus in a cryo-protectant context at varying temperatures
Our novel phase-separating technology which can form microbubble vaccine
depots is a promising method to alleviate stability issues which hinders the single
injection vaccine field. Enhancement of antigen stability in the microbubbles will be
determined in future work.
Citation
Lee, Jihui (2017). PHASE-SEPARATING MICROBUBBLES FUNCTIONING AS VACCINE DEPOTS. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /187285.