Chitosan-polycaprolactone copolymer microspheres for transforming growth factor-β1 delivery

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Regenerative Medicine

Background:

• Transforming growth factor-β1 (TGF-β1) is crucial for tissue regeneration.
• Developing effective delivery systems for TGF-β1 is essential for therapeutic applications.
• Chitosan-polycaprolactone (CPC) copolymers offer tunable properties for drug encapsulation.

Purpose of the Study:

• To fabricate and characterize TGF-β1-loaded CPC microspheres.
• To investigate the influence of formulation parameters on loading efficiency and release kinetics.
• To evaluate the performance of these microspheres in simulated physiological and pathological conditions.

Main Methods:

• Fabrication of CPC microspheres using an emulsification method.
• Crosslinking with sodium tripolyphosphate.
• Characterization of microsphere morphology, size, loading efficiency, and in vitro release profiles.
• Evaluation of release behavior in neutral and acidic (pH 6.5) conditions.

Main Results:

• Microspheres exhibited dense structure and regular sphericity (nanometer to micrometer scale).
• Loading efficiency exceeded 80% and was tunable by crosslinker amount and CPC composition.
• CPC composition significantly influenced swelling and release, while crosslinker effect was limited.
• Increased polycaprolactone content reduced initial burst release, enabling sustained TGF-β1 delivery.
• Acidic conditions modulated release, yet selected microspheres maintained sustained release without significant burst.

Conclusions:

• CPC microspheres are a promising platform for TGF-β1 delivery.
• Formulation composition is key to controlling drug release kinetics.
• These microspheres demonstrate potential for sustained TGF-β1 administration in conditions like cartilage lesions.