Hydrogel Photocrosslinking in real time
ElastoSens™ Bio Applications
In life sciences, photocrosslinkable hydrogels have been developed to overcome the low mechanical strength and processability of soft biomaterials including collagen, gelatin, hyaluronic acid, algina, chitosan, dextran, among others. These biomaterials contain photosensitive groups (such as methacryloyloxy) that are chemically introduced into their chains to allow their crosslinking under light exposure. These induced reactions make a liquid solution turn into a solid gel (gelation process) in a controlled manner.
The use of photocrosslinkable hydrogels offers many different strategies to control their final viscoelastic properties. The concentration of the biomaterial and photoinitiator, their degree of modification, the light intensity and exposure time can all be varied to fine tune the outcomes. With these many variables, it can be challenging to analyze the possible combinations in an effective way.
Applications on Hydrogel Photocrosslinking
All cells in the human body are exposed to mechanical forces which regulate cell function and tissue development, and each cell type is specifically adapted to the mechanical properties of the tissue it resides in. The matrix properties of human tissues can also change with disease and in turn facilitate its progression.
Gelatin and hyaluronic acid (HA) are biomaterials widely used in the biomedical research field. HA is the most abundant glycosaminoglycan in the body and is an important component of several tissues. HA contributes to tissue hydrodynamics, movement and proliferation of cells, and participates in a number of cell surface receptor interactions.
Hydrogels have been widely used in biomedical research for developing engineered tissues and novel treatments such as wound dressings and drug delivery systems. Photo-crosslinkable polymers are an interesting option in the field due to the possibility of tuning its microstructure by regulating the wavelength, intensity and duration of the applied light [1, 2, 3].
Mechanical Testing for Hydrogel Photocrosslinking
ElastoSens™ Bio can apply light at selected wavelengths (365 nm, 385 nm, and 405 nm – or others) during testing to obtain the crosslinking kinetics in real time of photosensitive biomaterials such as methacrylated hydrogels. These biomaterials can be poured directly into the sample holder and tested during crosslinking under controlled temperature, light exposure time and light intensity (in mW/cm2). The instrument measures, with no contact, real time changes in the sample height (or volume) and in the storage (G’) and loss (G’’) shear modulus which are immediately displayed on the tablet.
In this example, the evolution of the shear storage modulus (G’, Pa) as a function of time for a methacrylated gelatin (PhotoGel® 10%, Advanced BioMatrix, CA, USA) is shown under light exposure for 2, 4 and 6 minutes. The light was programmed to be switched on at 10 minutes of testing with the mentioned duration. Interestingly, the increase in G’ continued even after the light was switched off but at a lower rate. This means that the crosslinking reactions were still occurring for some minutes more (10-20 min).
ElastoSens™ Bio is able to capture the crosslinking kinetics under light exposure of photocrosslinkable hydrogels in real time. Scientists can now better understand the behavior of their biomaterials under different light intensities and exposure times. This also helps them to identify which light exposure time and intensity are needed to reach a target viscoelasticity.
Benefits of Contact-Free, Non-Invasive Measurements with the Elastosens™ Bio
- Test non-destructively the viscoelastic properties of bulk hydrogels, 3D bioprinted scaffolds and 3D cell-laden hydrogels.
- Apply programmable thermo and photo (UV) stimulations to deeply analyze your material.
- Follow the evolution of the same sample from formation to degradation non-destructively and over long periods of time.
- Get advanced and personalized Soft Matter Analytics™.
- Accelerate your formulation process while improving repeatability.
- Test bioengineered tissues in a cell-friendly and sterile environment.
- Operate a truly easy-to-use instrument designed for biologists, chemists and material scientists.
- Save time and material for R&D and QC operations.
- Customize your own testing system with up to 5 instruments thanks to the modularity of the ElastoSens™ Bio.
- Optimize your investments with affordable instruments that fit your needs and budget.