Development of alginate macroporous hydrogels using sacrificial CaCO₃ particles for enhanced hemostasis

Area of Science:

• Biomaterials Science
• Hemostasis and Thrombosis
• Polymer Chemistry

Background:

• Polymeric hydrogels are increasingly investigated for hemostatic applications.
• A need exists for non-dense polymeric hydrogels with incorporated pores to improve hemostasis.
• Current hydrogel designs often lack targeted pore development for enhanced hemostatic function.

Purpose of the Study:

• To develop a facile method for creating macroporous alginate hydrogels.
• To investigate the impact of macropores on hydrogel properties and hemostatic efficacy.
• To evaluate the in vivo performance of macroporous alginate hydrogels in bleeding models.

Main Methods:

• Macroporous alginate hydrogels were synthesized using acid-induced calcium carbonate (CaCO3) dissolution for Ca2+ ion release and CO2 bubble formation.
• Hydrogel pore structure and formation mechanisms were characterized using microscopic imaging and nitrogen adsorption/desorption.
• Functional properties including rheology, blood absorption, coagulation factor delivery, and platelet aggregation were assessed.

Main Results:

• Macroporous alginate hydrogels demonstrated improved rheological properties, enhanced blood absorption, and promoted coagulation factor delivery and platelet aggregation.
• In vivo studies in rat models showed significant reductions in blood loss (up to 77%) and bleeding time (up to 88%) with macroporous hydrogels.
• Higher porosity, achieved with a 40% CaCO3 to alginate ratio, resulted in superior hemostatic performance compared to lower porosity hydrogels.

Conclusions:

• A simple, facile method successfully produced macroporous alginate hydrogels with tunable porosity.
• The incorporated macropores significantly enhance the hemostatic effectiveness of alginate hydrogels.
• These biocompatible macroporous hydrogels represent a promising strategy for advanced hemostatic applications with minimal inflammation.