Implantable controlled delivery systems for proteins based on collagen--pHEMA hydrogels

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Co-polymeric hydrogels offer tunable properties for biomedical applications.
• Controlled release of therapeutic proteins is crucial for effective treatment.

Purpose of the Study:

• To develop and characterize collagen-pHEMA hydrogels for entrapping and releasing bovine serum albumin (BSA).
• To investigate the impact of cross-linking and porosity on BSA release kinetics.

Main Methods:

• Preparation of collagen-pHEMA hydrogels using redox initiation.
• Entrapment of fluorescein isothiocyanate (FITC)-labelled BSA.
• Modification of hydrogels via external cross-linking and ethylene glycol incorporation for porosity.
• In vitro release studies in phosphate buffer (pH 7.4, 37°C).
• Morphological analysis of hydrogels.

Main Results:

• Collagen-pHEMA hydrogels demonstrated zero-order release kinetics for FITC-BSA.
• Uncross-linked hydrogels released 81% of BSA in 8 days, while cross-linked hydrogels released 49%.
• Porous hydrogels exhibited rapid release (76% in 12 hours), with 19% released in the first hour.

Conclusions:

• Collagen-pHEMA hydrogel matrices can be modified to control BSA release rates.
• Cross-linking and porosity are key parameters for programming drug release profiles.
• These hydrogels show potential for controlled protein delivery applications.