Controlled release of phosphorothioates by protein-based polymers.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Protein-based polymers exhibit temperature-dependent phase transitions, influencing their solubility and interaction with charged molecules.
• The hydrophobicity of these polymers is a key factor in controlling transition temperature and the binding affinity for charged drugs via hydration forces.

Purpose of the Study:

• To investigate the use of protein-based polymers for the delivery of charged therapeutics, specifically phosphorothioates.
• To evaluate the programmability of drug release rates by modifying polymer composition.

Main Methods:

• Synthesized protein-based polymers incorporating lysine and varying amounts of phenylalanine (1 to 5 residues per 30).
• Studied the binding and release kinetics of phosphorothioates from these polymer systems.
• Measured drug release rates over time to assess programmability.

Main Results:

• Polymers with varying lysine and phenylalanine content successfully bound and released phosphorothioates.
• Achieved controlled release rates ranging from 4 to 64 nmol/cm²/day, sustained for 8 to 2 weeks/mm respectively.
• Demonstrated high programmability in controlling drug release kinetics through polymer design.

Conclusions:

• Protein-based polymers can be engineered for effective delivery of nucleic acid-based therapeutics.
• The tunable nature of these polymers allows for precise control over drug release rates.
• These findings highlight the potential of protein-based polymers in developing advanced therapeutic delivery systems.