Pore Interconnectivity Influences Growth Factor-Mediated Vascularization in Sphere-Templated Hydrogels

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Vascularization of biomaterials is critical for regenerative medicine applications.
• Scaffold architecture, particularly pore interconnectivity, influences vascularization but is less studied than pore size or porosity.

Purpose of the Study:

• To develop a method for creating hydrogel scaffolds with controlled pore interconnectivity.
• To investigate the impact of pore interconnectivity on vascularization in response to growth factor gradients.

Main Methods:

• A sintering method using poly(methyl methacrylate) microspheres as a sacrificial agent to fabricate poly(ethylene glycol) diacrylate hydrogels.
• Varying sintering time and temperature to control microsphere arrangement and hydrogel interconnectivity.
• In vivo evaluation of vascularized tissue formation in a rodent subcutaneous model.
• Utilizing an agent-based model to analyze transport and steric effects.

Main Results:

• Hydrogel interconnectivity was successfully controlled by adjusting microsphere sintering conditions.
• Higher pore interconnectivity led to significantly enhanced and faster vascularized tissue invasion in vivo.
• Interconnectivity influenced the transport of platelet-derived growth factor-BB (PDGF-BB) within the scaffolds.

Conclusions:

• A novel technique for fabricating hydrogels with tunable pore interconnectivity was established.
• Pore interconnectivity independently impacts and promotes biomaterial vascularization.
• This finding is significant for designing advanced scaffolds in regenerative medicine.