Covalent ECM Protein Coupling for Microfluidic Cell Adhesion
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Solution Overview
Problem
Current microfluidic devices face challenges in achieving long-term cell adhesion and viability due to the hydrophobic nature of silicone polymers like PDMS, which hinders cell attachment and can lead to detachment over time, even with surface treatments.
Innovation Solution
Covalently coupling ECM proteins or peptides, such as collagen and laminin, to the surface of microfluidic devices using crosslinkers like Sulfo-SANPAH, creating a stable attachment that allows for extended cell adhesion and viability under flow conditions, and enabling storage for later use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ECM proteins are coated on PDMS surface using conventional methods, then cell attachment is improved initially, but cell detachment occurs over time due to hydrophobic nature of PDMS
Solution Approach 1:
The patent applies preliminary action by performing plasma treatment on the PDMS surface before ECM protein coating. This pre-treatment modifies the surface chemistry to create hydrophilic regions that enhance subsequent protein adsorption and cell attachment. The plasma treatment is done in advance to ensure the surface is properly conditioned for long-term cell adhesion, preventing detachment that would otherwise occur due to PDMS hydrophobicity.
Solution Approach 2:
The patent changes the surface parameters of PDMS through plasma treatment, which modifies the chemical composition and surface energy of the polymer. This parameter change transforms the hydrophobic PDMS surface into a hydrophilic surface that can maintain stable ECM protein coating and support prolonged cell adhesion, directly addressing the duration problem.
2Ease of operation
If microfluidic devices are prepared with ECM coating, then they can be used immediately for cell culture, but storage for later use results in loss of cell attachment capability
Solution Approach 1:
The patent applies preliminary action by pre-coating the microfluidic device with ECM proteins and storing the device in a controlled manner before cell culture. This allows the device to be prepared in advance, stored for later use, and still maintain its cell attachment capability when ready for experimentation, eliminating the need for immediate use while preserving functionality.
Solution Approach 2:
The patent provides beforehand cushioning by storing the ECM-coated device under conditions that protect the coating integrity. This protective storage approach cushions against degradation that would otherwise occur during storage, ensuring the device retains its cell attachment capability even when used after storage periods.
3Reliability
If generic ECM coating is applied to culture surfaces, then cell adhesion is enhanced, but cell type-specific adhesion requirements are not met
Solution Approach 1:
The patent applies local quality by selecting and applying specific ECM protein types that match the requirements of particular cell types. Rather than using a generic ECM coating for all cells, the method tailors the protein composition (e.g., choosing specific collagens, fibronectin, or laminin) to the local needs of each cell type, thereby achieving both enhanced adhesion and cell type specificity.
Solution Approach 2:
The patent changes the chemical parameters of the ECM coating by selecting different protein compositions and concentrations based on cell type requirements. This parameter adjustment allows optimization of adhesion properties for specific cell types while maintaining the overall benefit of enhanced cell adhesion.
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
This approach enhances cell attachment and viability for at least 14 days, maintaining sustained function and allowing for the recreation of physiological tissue interfaces, even under fluid flow, with the ability to store the devices for later use without significant loss of cell attachment or morphology.
Implementation Method 1
ECM protein(s) is covalently coupled to the surface of a microchannel of a microfluidic device
Implementation Method 2
the silicone polymer is polydimethylsiloxane or 'PDMS.' In one embodiment, the ECM protein is covalently coupled to a PDMS surface using a crosslinker, such as the heterobifunctional linker N-sulphosuccinimidyl-6-(4′-azido-2′-nitrophenylamino) hexanoate (Sulfa-SANPAH)
Implementation Method 3
The surface can be plasma treated prior to step b)
Implementation Method 4
The crosslinker is activated with UV light in the presence of a mask
Implementation Method 5
the living cells are exposed to fluid flow, the fluid flow providing shear stress
Data Source
AI summary
Compositions, devices and methods are described for improving adhesion, attachment, and/or differentiation of cells in a microfluidic device or chip. In one embodiment, one or more ECM proteins are covalently coupled to the surface of a microchannel of a microfluidic device. The microfluidic devices can be stored or used immediately for culture and/or support of living cells such as mammalian cells, and/or for simulating a function of a tissue, e.g., a liver tissue, muscle tissue, etc. Extended adhesion and viability with sustained function over time is observed.