TGF-β1 activation in human hamstring cells through growth factor binding peptides on polycaprolactone surfaces

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Soluble growth factors (GFs) enhance tendon and ligament (T/L) healing but require complex, expensive, and regulated administration at supraphysiological concentrations.
• Spatial immobilization of GFs is critical for effective T/L healing.
• Current methods for GF delivery are often suboptimal, necessitating novel strategies.

Purpose of the Study:

• To develop and evaluate biomaterials functionalized with GF-binding peptides for capturing endogenous GFs.
• To investigate if these functionalized biomaterials can promote T/L healing by presenting captured GFs in a spatially controlled manner.
• To overcome the limitations of exogenous GF administration for T/L repair.

Main Methods:

• Modification of polycaprolactone (PCL) films with transforming growth factor β1 (TGF-β1)-binding peptides.
• Assessment of GF capture and biological activity using reporter cell lines and immunocytochemistry.
• In vitro evaluation of collagen matrix production in human primary tendon cells.
• In vivo implantation in rats to assess GF accumulation, inflammatory response, fibrogenesis, and vascularization.

Main Results:

• PCL films functionalized with TGF-β1-binding peptides successfully captured and presented biologically active TGF-β1.
• Immobilized TGF-β1 significantly increased collagen matrix production in tendon cells.
• In vivo studies showed enhanced endogenous TGF-β1 accumulation on functionalized films.
• Functionalized films promoted inflammatory cell recruitment, fibrogenic response, and vascularization around the implant.

Conclusions:

• Biomaterials functionalized with GF-binding peptides offer a novel strategy for capturing endogenous GFs, promoting T/L healing.
• This approach overcomes the need for exogenous supraphysiological GF administration, simplifying and potentially reducing the cost of T/L repair.
• Functionalized biomaterials can impart novel biological properties to medical devices, accelerating T/L healing.