Injectable Photoacoustic-Traceable Prussian Blue Nano-hybridized Hydrogel Microspheres Loaded with Stem Cells for...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Nanotechnology

Background:

• Diabetic patients exhibit impaired tooth extraction wound healing due to elevated reactive oxygen species (ROS) compromising bone marrow mesenchymal stem cells (BMSCs).
• Prussian blue nanoparticles (PBNPs) are effective ROS scavengers, but lack suitable delivery systems for clinical use.
• Current limitations include the need for stable, targeted, and minimally invasive delivery methods for PBNPs in bone regeneration.

Purpose of the Study:

• To develop and evaluate an injectable, photoacoustic imaging-trackable microsphere system encapsulating PBNPs for enhanced bone defect repair in diabetic rats.
• To assess the in vitro and in vivo efficacy of the GelMA/PEGDA/PBNPs microspheres in improving BMSC function and bone regeneration.
• To investigate the underlying molecular mechanisms, including the PI3K/AKT/mTOR pathway, involved in the therapeutic effects.

Main Methods:

• Fabrication of injectable GelMA/PEGDA/PBNPs microspheres using microfluidic technology.
• In vitro assessment of microsphere properties, including mechanical strength, biodegradability, ROS scavenging, BMSC proliferation, and osteogenesis.
• In vivo evaluation of microsphere efficacy in accelerating bone defect regeneration in diabetic rat models, coupled with photoacoustic imaging for tracking.

Main Results:

• The GelMA/PEGDA/PBNPs microspheres demonstrated favorable mechanical properties, controlled degradation, and enhanced stem cell expansion and osteogenic differentiation in vitro.
• In vivo studies showed accelerated regeneration of bone defects in diabetic rats treated with the microsphere system, with improved local retention and sustained PBNP release.
• Transcriptomic analysis revealed that the antioxidant effects were linked to the activation of the PI3K/AKT/mTOR signaling pathway.

Conclusions:

• The developed nano-hybrid microsphere system offers a novel, minimally invasive therapeutic strategy for addressing bone tissue defects in diabetic patients.
• The system's ability to deliver PBNPs effectively, enable real-time tracking, and promote bone regeneration shows significant potential for clinical translation.
• Targeted delivery and ROS scavenging via this advanced microsphere platform represent a promising approach for improving healing outcomes in diabetic individuals.