(F-223) Development of Dual Pro-Angiogenic Agents Loaded Nanoparticles for Treatment of Peripheral Arterial Disease

Introduction:: Peripheral arterial disease (PAD), which affects approximately 8.5 million Americans, especially the elderly, is a condition caused by narrowing of arteries due to atherosclerosis in the lower limb and consists of insufficient blood flow and lack of oxygen and nutrients to muscle tissues. PAD, with critical limb ischemia, has high mortality and morbidity rates. Since the current invasive treatments for PAD have many complications and disadvantages, developing innovative approaches to overcome these limitations is in high demand and critical for long-term health. Therefore, we propose a non-invasive, alternative approach using nanocarriers to deliver and provide controlled releases of dual pro-angiogenic factors to ischemic tissues in order to stimulate cell growth, promote cell migration, prevent cell death, and enhance angiogenesis for treating PAD.

Materials and Methods:: Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) encapsulating dual pro-angiogenic factors were synthesized using a standard double emulsion technique. The NPs size and polydispersity were characterized using a dynamic light scattering (DLS) method. The in vitro therapeutic effect of these NPs was investigated on endothelial progenitor cells (EPCs). Cell survival was assessed under a stress-induced condition to mimic PAD pathology. Cell proliferation was also studied at low serum conditions and observed for up to 7 days. Cell viability of both experiments were measured using MTS assays. A transmigration study using a 24-well Transwell system was also used to investigate cell transmigration after 12 hours of NPs’ treatment. The transmigrated cells to the lower chamber were imaged and quantified by ImageJ after DAPI nuclei staining

Results, Conclusions, and Discussions:: The NPs were successfully fabricated with average diameters of around 250 nm and had an acceptable range of polydispersity. In vitro testing has demonstrated that dual-factor NPs can prevent cell apoptosis by almost 2 times compared to no treatment under ROS stressed environments, and they outperformed free pro-angiogenetic factors. Cell growth was also boosted by these NPs until Day 7 (Figure 1). The effect of NPs on EPCs were further demonstrated via the enhanced cell migration compared to no treatment using the Transwell system after 12 hours.
PLGA NPs can be used to encapsulate dual pro-angiogenetic factors as an alternative and non-invasive approach to treat PAD. The NPs have demonstrated their ability to increase cell growth, prolong cell viability in stress conditions, and improve cell migration based on our in vitro results. More in vitro studies will be conducted to study angiogenesis of these NPs such as tube formation using Matrigel. In vivo studies will be further performed to investigate the promising effects of these NPs on PAD mouse models. Physical endurance using treadmill and blood perfusion with laser doppler perfusion imaging will be used to assess the therapeutic effects of these NPs on PAD mice.


Acknowledgements (Optional): :

References (Optional): :