Tyrosol Derived Poly(ester-arylate)s for Sustained Drug Delivery from Microparticles

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Current biodegradable polymers, like poly(lactide-co-glycolide) (PLGA), exhibit limitations in drug delivery systems, including high burst release, insufficient sustained release, and acidic degradation products.
• There is a need for advanced biodegradable polymers that can provide controlled and sustained release of therapeutic agents, particularly hydrophobic drugs.

Purpose of the Study:

• To develop and evaluate a novel tyrosol-derived poly(ester-arylate) library for microparticle drug delivery systems.
• To assess the potential of these new polymers in achieving sustained release of hydrophobic drugs and compare their performance to PLGA.

Main Methods:

• A library of biocompatible and biodegradable tyrosol-derived poly(ester-arylate) polymers with varying hydrophilicity and thermal properties was synthesized.
• Microparticle drug delivery systems were prepared using these polymers to encapsulate hydrophobic model drugs (curcumin, dexamethasone).
• Drug loading, particle characteristics (glass transition temperature), and drug release profiles were analyzed and compared to PLGA formulations.

Main Results:

• Hydrophobic drugs curcumin and dexamethasone were successfully loaded into the tyrosol-derived poly(ester-arylate) microparticles up to 50 wt %.
• A linear correlation was observed between the weight percentage of drug loaded and the particle glass transition temperature (Tg).
• Drug release studies demonstrated sustained release up to 77 days with higher polymer concentrations, outperforming PLGA's 63-day release and showing biphasic release with lower concentrations (47 days).

Conclusions:

• The novel tyrosol-derived poly(ester-arylate) library provides a promising platform for developing injectable, long-term release drug delivery formulations.
• These new polymers effectively overcome the limitations of burst release and acidic degradation associated with traditional PLGA systems.
• The ability to control release rates by adjusting polymer concentration offers flexibility in designing tailored drug delivery profiles.