Cellulose crosslinked pH-responsive polyurethanes for drug delivery: α-hydroxy acids as drug release modifiers

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Developing advanced drug delivery systems is crucial for targeted and effective therapeutic outcomes.
• Polyurethanes (PUs) offer versatile properties for biomedical applications, but require modification for controlled release.
• pH-sensitive carriers can improve drug efficacy by releasing therapeutics at specific physiological sites.

Purpose of the Study:

• To synthesize and characterize cellulose crosslinked polyurethanes (PUs) for drug delivery.
• To investigate the pH-dependent release of felodipine from these novel PU carriers.
• To evaluate the suitability of these PUs for specific medical applications like vaginal and colon-specific drug delivery.

Main Methods:

• Preparation of cellulose crosslinked waterborne polyurethanes using poly ɛ-caprolactone and specific acid modifiers.
• Loading of felodipine into the PU matrix.
• Characterization of polymer structure and morphology using FTIR, DSC, TGA, and SEM.
• Monitoring of drug release profiles at different pH values (e.g., pH 1.2 and pH 7.4).

Main Results:

• Successfully synthesized cellulose crosslinked PUs with tunable properties.
• Demonstrated pH-sensitive drug release, with significantly faster felodipine release at pH 7.4 compared to pH 1.2.
• Observed degradation of PUs under highly basic conditions.
• Confirmed drug encapsulation within the PU matrix and analyzed polymer morphology post-drug release via SEM.

Conclusions:

• The developed PUs function as effective pH-sensitive drug carriers with modulated release rates.
• The choice of acid chain extenders influences the drug release kinetics.
• These PUs show promise for medical applications, particularly in vaginal and colon-specific drug delivery systems.