3D Printed Sacrificial Vascular Templates for Tissue Scaffolds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for engineering tissues fail to create thick, physiologically relevant tissues with intricate vascular networks that can sustain cell viability and facilitate long-term remodeling, as they lack mechanical strength and controlled vascular geometries, relying on angiogenesis which is random and lacks long-term functionality.
Innovation Solution
An extrusion-based 3D printing method is used to create a scaffold with a sacrificial vascular template made of polyester wax, which is embedded in a hydrogel solution, lyophilized, and crosslinked to form a robust scaffold with controlled vascular geometries, allowing for the introduction of cells into the lumens and pores, enhancing mechanical strength and biostability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If traditional scaffold fabrication techniques are used, then porous structures can be achieved, but intricate vascular networks cannot be incorporated
Solution Approach 1:
The patent applies preliminary action by fabricating the vascular network template before the scaffold itself. The vascular template is created first using 3D printing, then embedded in the hydrogel solution during scaffold fabrication. This sequence allows the complex vascular geometry to be established beforehand, avoiding the need to create it within the porous structure formation process.
Solution Approach 2:
The patent uses a sacrificial vascular template as an intermediary object. This template, made of removable material, serves as a mediator that defines the vascular network geometry during scaffold fabrication, then is removed to leave the desired vascular channels. The intermediary template enables the creation of complex vascular structures without directly forming them in the final scaffold.
2Volume of moving object
If thick tissues are engineered, then tissue depth is increased, but cell viability decreases due to insufficient oxygen and nutrient supply
Solution Approach 1:
The patent applies segmentation by dividing the thick tissue into regions supplied by an engineered vascular network. Instead of relying on diffusion from the surface, the tissue is segmented into vascular territories with embedded vessels that deliver oxygen and nutrients directly to deep regions, enabling cell viability throughout the entire tissue thickness.
Solution Approach 2:
The patent transitions from surface-level nutrient supply to three-dimensional vascular distribution. By embedding vessels throughout the tissue depth rather than relying on surface diffusion, the system adds a vertical dimension to nutrient delivery, enabling sustained cell viability in thick tissues that would otherwise be inaccessible to diffusion.
3Manufacturing precision
If sacrificial vascular templates are used, then controlled vascular geometries are achieved, but template removal complexity increases
Solution Approach 1:
The patent uses phase transitions by selecting sacrificial template materials that undergo predictable phase changes (melting, dissolution, or degradation) under controlled conditions. This allows the template to be removed through a simple phase change process rather than mechanical extraction, reducing the complexity of template removal while maintaining precise vascular geometry control during fabrication.
4Manufacturing precision
If extrusion-based 3D printing is used, then vascular templates with controlled geometry are produced, but material homogeneity becomes challenging
Solution Approach 1:
The patent applies parameter changes by controlling temperature, pressure, and flow rate parameters during extrusion-based 3D printing. By optimizing these parameters, the system achieves both precise vascular template geometry and homogeneous material composition, resolving the contradiction between geometric precision and material uniformity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces scaffolds with robust vascular networks that support cell attachment and nutrient transport, improving tissue survival and enabling controlled angiogenesis, thereby overcoming the limitations of existing techniques in creating functional engineered tissues.
Implementation Method 1
the template can be removed by melting the wax
Implementation Method 2
After lyophilization and crosslinking, thereby forming a structurally robust scaffold
Data Source
AI summary
A method and device for fabricating vascular networks in for tissue engineering. The vascular network is embedded in a porous scaffold and is created from a sacrificial wax template, according to one embodiment. A extrusion-based three dimensional printer is used to create the template, wherein the printer utilizes an extruder incorporating a mixer to maintain the consistency of the extrudate.