Mechanical characterization and numerical simulation of a subcutaneous implantable 3D printed cell encapsulation...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Biotechnology

Background:

• Cell transplantation in bioengineered scaffolds is crucial for regenerative medicine.
• Effective systems require physiological environments, mechanical support, and long-term cell viability.
• Minimally invasive delivery systems are needed for subcutaneous cell transplantation.

Purpose of the Study:

• To evaluate the long-term in vivo mechanical suitability of the neovascularized implantable cell homing and encapsulation (NICHE) system.
• To validate a constitutive material model for predicting the mechanical behavior of the NICHE device.
• To assess the durability of the NICHE system for subcutaneous implantation of endocrine cells, such as pancreatic islets.

Main Methods:

• Developed a 3D printed NICHE system using polylactic acid.
• Assessed mechanical behavior of fresh NICHE devices under simulated subcutaneous conditions.
• Evaluated NICHE devices retrieved after subcutaneous implantation in pigs.
• Performed experimental and numerical studies to validate the constitutive material model.

Main Results:

• A homogeneous isotropic constitutive material model, calibrated via uniaxial testing, accurately predicted experimental results.
• The NICHE system demonstrated long-term durability suitable for in vivo applications.
• The validated model shows potential for predicting device behavior in various physiological settings.

Conclusions:

• The NICHE system is mechanically robust for long-term subcutaneous implantation.
• The validated material model enhances the predictability of device performance in regenerative medicine.
• This study supports the NICHE system's potential for endocrine cell transplantation and other in vivo applications.