Branched biodegradable polyesters for parenteral drug delivery systems

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Achieving continuous drug release from biodegradable parenteral systems for hydrophilic macromolecules like proteins is challenging with linear polyesters (PLA, PLG).
• Modifying polyester hydrophilicity or polymer architecture is key to controlling degradation and drug release rates.

Purpose of the Study:

• To investigate novel branched polymer architectures for biodegradable polyesters.
• To enhance protein delivery from parenteral systems using tailored polymer properties.

Main Methods:

• Synthesized star-branched polyesters by grafting poly(ethylene oxide) (PEO) onto multi-arm PEO cores.
• Created comb-like polyesters using dextrans or poly(vinyl alcohol) (PVA) as hydrophilic backbones.
• Characterized polymers using NMR, IR, SEC-SLS, DSC, and viscosity measurements.

Main Results:

• Star-branched polyesters exhibited unique degradation behavior, retaining PEO blocks longer than ABA triblock copolymers, but required further optimization for release profiles.
• Brush-like branched polyesters demonstrated promising degradation and release properties suitable for parenteral protein delivery.
• Characterization confirmed tailor-made properties of the novel branched polyesters.

Conclusions:

• Branched biodegradable polyesters, particularly brush-like structures, are promising for parenteral protein delivery systems.
• Further investigation into brush-like branched polyesters is warranted due to their favorable degradation and release characteristics.
• Optimized polymer architecture is crucial for achieving desired drug release profiles in parenteral applications.