Jammed Gel Bioink Using Self-Assembling Peptides
Solution Overview
Problem
Current bioinks for 3D printing of tissues face challenges in being extrudable, non-toxic to living cells, capable of retaining shape, biocompatible, and customizable to mimic native tissue environments, while also supporting cell growth and immune response avoidance.
Innovation Solution
A jammed gel bioink is developed using a self-assembling peptide solution extruded to form a shape, with a cell solution injected to be surrounded by the peptide solution, utilizing peptides like RADA16 and peptidomimetics, and a cell culture medium to ensure cell viability and growth, allowing for customizable and biodegradable tissue analogs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If cells are mixed with printing medium and extruded to form tissue structures, then the desired shape can be achieved, but the material must remain non-toxic to living cells throughout the process
Solution Approach 1:
The bioink is segmented into two separate components: a self-assembling peptide solution (without cells) that provides structural integrity and shape retention, and a cell solution that contains living cells suspended in culture medium. These components are extruded separately or in a controlled sequence, allowing the peptide to form the structural framework first, followed by cell incorporation. This segmentation eliminates the need for cells to be exposed to potentially toxic crosslinking agents or extrusion conditions, as cells are added after the peptide structure is formed.
Solution Approach 2:
The self-assembling peptide solution is extruded and allowed to self-assemble into the desired structural framework before cells are introduced. This preliminary formation of the peptide matrix creates a safe, pre-formed structure that can then receive cells without exposing them to toxic conditions during the assembly process. The peptide undergoes its self-assembly and crosslinking reactions first, establishing a non-toxic environment before cell incorporation.
2Strength
If cross-linking is performed quickly after extrusion to retain stiffness, then shape retention is improved, but the process must remain cell-friendly and non-toxic
Solution Approach 1:
The cross-linking process is segmented from cell exposure. The self-assembling peptide undergoes rapid cross-linking to achieve stiffness and shape retention in a cell-free environment or under controlled conditions. Once the peptide matrix is crosslinked and structurally stable, cells are then introduced into the pre-formed matrix. This temporal and spatial segmentation allows rapid cross-linking without exposing cells to potentially toxic crosslinking agents.
Solution Approach 2:
The self-assembling peptide acts as an intermediary between the extrusion process and cell incorporation. It provides a bridge that allows rapid cross-linking to occur in the absence of cells, creating a safe structural framework that then serves as a host for cell incorporation. The peptide mediates the transition from a liquid state amenable to extrusion to a solid, stiff matrix suitable for cell housing.
3Reliability
If the bioink is designed to mimic native tissue environment for cell attachment and growth, then biocompatibility is improved, but the material must also be easily extrudable and customizable for different applications
Solution Approach 1:
The self-assembling peptide system provides universal functionality that satisfies multiple requirements: it forms extrudable solutions that can be printed into various shapes, self-assembles into matrices that mimic native tissue environments with appropriate mechanical properties and biochemical cues, and serves as a customizable platform for different cell types and tissue applications. The same basic peptide system can be adapted for soft tissues, medium-stiffness tissues, or hard tissues by adjusting peptide concentration, sequence, or crosslinking density.
Solution Approach 2:
The bioink system allows parameter changes to achieve different tissue types and applications. By modifying peptide concentration, molecular weight, amino acid sequence, or crosslinking conditions, the same self-assembling peptide system can produce matrices with different stiffness, porosity, and degradation rates suitable for various tissue types (soft, medium, hard tissues). These parameter adjustments enable customization while maintaining the core self-assembling mechanism that provides biocompatibility and extrudability.
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 bioink is easily extrudable, non-toxic, and customizable, supporting cell growth and tissue mimicry, with cells remaining viable for extended periods within the printed matrix, addressing the limitations of existing bioinks in bioprinting technology.
Implementation Method 1
a self-assembling peptide solution comprising a self-assembling peptide
Data Source
AI summary
A jammed gel bioink comprises a self-assembling peptide solution comprising a self-assembling peptide, and a cell solution comprising living cells and a cell culture medium. The self-assembling peptide solution is extruded to form an object, and then the cell solution is injected into the object. Useful methods of making the jammed gel bioink are also disclosed.