Rapid Prototyping of Polyurethane Auricle Cartilage Scaffold

Advanced tissue engineering approaches for ear reconstruction using 3D-printed polyurethane scaffolds

Tissue Engineering 3D Printing Biomaterials

Introduction

Auricular reconstruction remains a significant challenge in reconstructive surgery, particularly for patients with congenital microtia or traumatic ear loss. Traditional approaches often involve autologous cartilage harvesting, which is associated with donor site morbidity and limited availability .

Polyurethane scaffolds offer a promising alternative due to their tunable mechanical properties, biocompatibility, and ability to support chondrocyte proliferation and extracellular matrix production .

Rapid prototyping technologies, particularly 3D printing, have revolutionized the fabrication of patient-specific scaffolds with complex anatomical geometries . This study explores the development and characterization of polyurethane auricle cartilage scaffolds using advanced rapid prototyping techniques.

Biocompatibility

Excellent cell adhesion and proliferation with minimal inflammatory response.

Customization

Patient-specific designs based on CT or MRI data for precise anatomical fit.

Methodology

Scaffold Design

3D models of human auricles were created based on CT scans of healthy volunteers. The models were optimized for printing using specialized software to create porous structures with interconnected channels .

Material Preparation

Medical-grade polyurethane was selected for its mechanical properties and biocompatibility. The polymer was processed to achieve appropriate viscosity for printing .

3D Printing

Scaffolds were fabricated using a customized extrusion-based 3D printer. Printing parameters were optimized to achieve high resolution and structural integrity .

Characterization

Scaffolds were evaluated for mechanical properties, porosity, and degradation profile. In vitro studies assessed chondrocyte attachment and proliferation .

Printing Parameters
Material Properties

Results

1
Structural Integrity

Scaffolds maintained anatomical shape with porosity of 75-85% and pore sizes of 150-300μm .

2
Mechanical Properties

Compressive modulus of 0.8-1.2 MPa, comparable to native auricular cartilage .

3
Cell Viability

Chondrocyte viability >90% after 14 days, with significant extracellular matrix production .

Scaffold Performance Metrics
Key Properties
Biocompatible Tunable Stiffness Controlled Degradation High Porosity Patient-Specific Sterilizable

Discussion

The rapid prototyping approach successfully produced patient-specific polyurethane auricle scaffolds with appropriate structural and mechanical properties for cartilage tissue engineering . The interconnected porous network facilitated nutrient diffusion and waste removal, supporting chondrocyte viability and function.

The combination of medical-grade polyurethane and advanced 3D printing technology represents a significant advancement in auricular reconstruction, potentially reducing surgical complexity and improving aesthetic outcomes .

Future work will focus on long-term in vivo studies to assess scaffold integration, cartilage formation, and immunological response. Additionally, optimization of surface modifications to enhance chondrocyte attachment and differentiation is underway .

Future Research Directions
Key Findings
  • Printing Accuracy 95%
  • Cell Viability 92%
  • Porosity 80%
  • Compression Modulus 1.0 MPa
Timeline
Week 1-2

Scaffold design & optimization

Week 3-4

Material preparation & testing

Week 5-8

3D printing & characterization

Week 9-12

In vitro evaluation

Applications
Congenital Microtia Traumatic Injury Cancer Reconstruction Cosmetic Surgery