Precision stem cell regeneration enabled by a collagen-targeting, fate-directing bi-functional peptide.

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Cell Biology

Background:

• Stem cell therapy faces challenges in precise control of cell delivery and fate.
• Osteoarthritis and severe corneal defects require advanced regenerative strategies.

Purpose of the Study:

• To develop and evaluate a collagen-targeting, fate-directing bi-functional peptide (BiFP) for enhanced stem cell therapy.
• To assess BiFP's efficacy in improving multipotent stromal cell (MSC) homing, engraftment, and tissue regeneration in osteoarthritis and corneal defect models.

Main Methods:

• BiFP was synthesized and characterized for purity, molecular weight, and structural integrity using nano-LC-MS/MS, HPLC, SDS-PAGE, MALDI-TOF, CD, DSC, and DSF.
• Biophysical properties including nanoparticle formation were assessed using DLS and TEM.
• In vivo studies involved delivering BiFP-bound MSCs intra-articularly and ocularly in rat models, followed by cell tracking and pharmacokinetic analysis.

Main Results:

• BiFP demonstrated stable triple-helix formation and formed nanoparticles (∼1.4 nm).
• Delivery of BiFP-bound MSCs significantly enhanced cell homing, engraftment, and regeneration of neocartilage and corneal epithelium in rat models.
• In vivo tracking confirmed MSC differentiation into chondrocytes and corneal epithelial cells, mediated partly by FAK-FoxO signaling. Pharmacokinetic studies indicated rapid clearance of free BiFP with kidneys as the primary excretion route.

Conclusions:

• BiFP serves as a modular, extracellular matrix-guided delivery platform for precise localization and fate control of transplanted stem cells.
• This peptide-based approach offers a promising strategy for targeted regenerative therapies with improved safety and efficacy.