Enzymatically cross-linked injectable alginate-g-pyrrole hydrogels for neovascularization.

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Regenerative Medicine

Background:

• Injectable hydrogels are used for controlled protein drug delivery, but sustained release remains a challenge.
• Current methods often struggle to maintain drug bioactivity over extended periods at implantation sites.
• There is a need for advanced hydrogel formulations that provide prolonged and controlled release of therapeutic proteins.

Purpose of the Study:

• To investigate a novel hydrogel system for sustained protein drug release.
• To test the hypothesis that pyrrole-crosslinked alginate hydrogels enhance drug association and prolong release.
• To evaluate the in vivo efficacy of the developed hydrogel system for promoting angiogenesis.

Main Methods:

• Preparation of alginate-g-pyrrole hydrogels via horse-radish peroxidase (HRP)-activated cross-linking.
• Encapsulation of poly(lactic-co-glycolic acid) (PLGA) microparticles loaded with vascular endothelial growth factor (VEGF).
• Assessment of VEGF release kinetics compared to control hydrogel systems (Ca(2+) alginate, Ca(2+) alginate-g-pyrrole).
• In vivo evaluation of the hydrogel system's angiogenic potential on chicken chorioallantoic membranes.

Main Results:

• The alginate-g-pyrrole hydrogel system exhibited significantly more sustained release of VEGF compared to control groups.
• Implantation on chicken chorioallantoic membranes resulted in increased blood vessel density and diameter.
• The HRP-activated cross-linking method effectively created a hydrogel matrix for controlled protein delivery.

Conclusions:

• Pyrrole-crosslinked alginate hydrogels provide a robust platform for sustained protein drug release.
• This novel drug delivery system effectively promotes angiogenesis, demonstrating therapeutic potential.
• The developed system offers broad applicability for enhancing protein drug therapies through controlled release mechanisms.