Cyclodextrin-Based Polyrotaxane-Protein Hybrids for Shear-Thinning 3D Printing

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Solution Overview

Problem

Current rotaxanes have limitations in fabrication and properties optimal for three-dimensional (3D) printing, particularly requiring high molecular weight PEGs and lacking suitable shear-thinning and self-healing properties, which results in brittle hydrogels or crystalline precipitates.

Innovation Solution

Development of rotaxane compositions with macrocyclic rings threaded onto polymers covalently appended with sterically hindered molecules, allowing for lower molecular weight polymers and improved control over threading and crystallization processes, forming crystalline networks with enhanced viscoelastic properties suitable for 3D printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high molecular weight PEGs are used to form rotaxanes, then the hydrogels have sufficient structural integrity, but the materials become brittle and lack suitable shear-thinning and self-healing properties for 3D printing

Engineering Contradiction:

Improvestructural integrityVSAvoidshear-thinning and self-healing properties

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The patent changes the molecular weight parameter of PEG from high (conventional) to low (below 10,000 Da), and modifies the rotaxane structure by covalently appending sterically hindered molecules to the PEG chain ends. This parameter change enables the hydrogel to exhibit both structural integrity and 3D-printable rheological properties including shear-thinning and self-healing behavior

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite rotaxane structure combining PEG polymer chains with macrocyclic rings (such as cyclodextrins) and sterically hindered end molecules. This composite structure provides both the mechanical strength needed for hydrogel formation and the controlled rheological properties required for 3D printing

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If polymers with lower molecular weight are used, then the rotaxane compositions have improved viscoelastic properties and are suitable for 3D printing, but the hydrogels may lack sufficient strength

Engineering Contradiction:

Improveviscoelastic properties for 3D printingVSAvoidhydrogel strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The patent uses sterically hindered molecules as intermediary elements covalently attached to the PEG chain ends. These intermediary groups act as stoppers that prevent macrocyclic ring detachment while also influencing the rheological properties, enabling low molecular weight PEG to form strong, 3D-printable hydrogels

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If conventional rotaxane structures are used without sterically hindered molecules, then the fabrication process is simpler, but the threading and crystallization processes lack control resulting in brittle precipitates

Engineering Contradiction:

Improvefabrication simplicityVSAvoidcontrol over threading and crystallization

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by covalently appending sterically hindered molecules to the PEG chain ends before the threading process. This preliminary modification controls the subsequent threading of macrocyclic rings and the crystallization process, preventing uncontrolled aggregation and brittle precipitate formation

Inventive Principle:

Principle #10Preliminary action

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 compositions enable 3D-printable hydrogels with significantly improved elastic moduli, transforming weak hydrogels into 3D-printable materials with tunable properties, including elastic moduli up to two orders of magnitude higher, suitable for applications like tissue engineering scaffolds.

Implementation Method 1

The plurality of macrocyclic rings are threaded onto the polymer through the cavities of the macrocyclic rings

Methodology Applied

Scientific EffectThreading through cavities:

Implementation Method 2

each of the plurality of different segments is in the form of a crystalline network

Methodology Applied

Scientific EffectCrystallization: Crystallisation

Implementation Method 3

The compositions enable 3D-printable hydrogels with significantly improved elastic moduli

Methodology Applied

Scientific EffectHydrogel formation: Hydrogel

Data Source

PatentUS12421326B2Cyclodextrin-based polyrotaxanes and protein hybrids as three-dimensional printing inks

Publication Date: 2025.09.23 TRUSTEES OF DARTMOUTH COLLEGE THE

AI summary

Embodiments of the present disclosure pertain to a composition that includes a rotaxane. The rotaxane includes a plurality of macrocyclic rings and a polymer with a molecular weight below 10,000 Da that is covalently appended to one or more sterically hindered molecules. The cavities of the macrocyclic rings are threaded onto the polymer. The plurality of threaded macrocyclic rings include a plurality of different segments that each include a plurality of threaded macrocyclic rings. Each of the plurality of different segments is in the form of a crystalline network. Further embodiments of the present disclosure pertain to methods of forming the rotaxanes by covalently appending one or more sterically hindered molecules onto a polymer and threading a plurality of macrocyclic rings onto the polymer. Additional embodiments of the present disclosure pertain to methods of manufacturing a three-dimensional structure by applying a composition of the present disclosure onto a surface.