Researchers from Italy and Sweden add to the ongoing trend for improving bioprinting techniques and materials. Upon developing bio-based photocurable materials for 3D printing and bioprinting with hydrogels, the authors released the details of their study in ‘DLP 3D Printing Meets Lignocellulosic Biopolymers: Carboxymethyl Cellulose Inks for 3D Biocompatible Hydrogels.’
Modified carboxymethyl cellulose was at the center of this experiment for bioprinting with digital light processing (DLP). While more commonly used as a filler, cellulose has been used in other inks. Beginning the research with the study of lignocellulosic biopolymers, the authors explained that they present a range of options for printing with DLP, while carboxymethyl cellulose (CMC) is often used in food, paint, and detergents. For this reason, it is a sustainable material with particular utility in bioprinting.
Approved by the FDA, and deemed biocompatible, CMC is water-soluble, versatile, and considered “an ideal candidate for the preparation of novel photocurable resins for DLP.” These types of formulations can also imitate cell microenvironments because of their similar makeup to glycosaminoglycan found within the extracellular matrix.
“Due to its versatility, its advantageous properties, water-solubility, and susceptibility to further functionalization, we also expected CMC would be an ideal candidate for the preparation of novel photocurable resins for DLP,” explained the authors. “However, the use of light-assisted printing techniques requires reactive photocrosslinkable functional groups, which means CMC needs functionalization to produce ink formulation for the production of 3D photocured hydrogels.
“CMC was therefore methacrylated and its photorheology and DLP printability was investigated in two formulations, namely, M-CMC/Dulbecco’s Modified Eagle Medium (DMEM) and M-CMC/water, in presence of a fixed amount of lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator.”
During evaluation, the authors also investigated compatibility for hydrogels, with M-CMC solubilized in a culture medium (DMEM). Rheological properties (storage modulus, G′, and loss modulus, G″) were evaluated during UV curing for CMC/DMEM/LAP and M-CMC/water/LAP:
“Although the formulation M-CMC/DMEM/LAP showed a slight delay with respect to the onset of the curing process, the DMEM medium still allowed sufficient light penetration for the photocuring process in view of 3D printing,” said the researchers.
Both the CMC/DMEM/LAP and M-CMC/water/LAP formulations proved to be stable after 90 s of UV irradiation. Hydrogels were created from both formulations, and deemed “extremely promising” in comparison with other DLP biocompatible materials.
The researchers created a variety of 3D printed samples, to include cylinders, parallelepipeds, and other complex structures—all stemming from the M-CMC/DMEM/LAP and M-CMC/water/LAP formulations. On further evaluation, the hydrogels were stable, flexible, and the photocrosslink reaction was completed. Although dyes can be helpful in limiting light diffusion, there is also the risk of cytotoxicity, leading the authors to avoid such use in this study.
Crosslinking and reactivity were further evaluated, along with compression tests, assessment of swelling ability, and cytotoxicity testing to investigate lack of cell death due to release of LAP photoinitiator or unreacted polymer chains. Ultimately, the team of researchers reported that there were no signs of cytotoxicity, and overall, their work was successful with cells exhibiting viability similar to control samples.[Source / Images: ‘DLP 3D Printing Meets Lignocellulosic Biopolymers: Carboxymethyl Cellulose Inks for 3D Biocompatible Hydrogels’]
Subscribe to Our Email Newsletter
Stay up-to-date on all the latest news from the 3D printing industry and receive information and offers from third party vendors.
You May Also Like
Entire Nanosatellite 3D Printed within Single nScrypt 3D Printer
Under a Small Business Innovation Research (SBIR) Phase II research grant with the Space Force, Sciperio relied on 3D printers from its sister company nScrypt to make small six unit...
NASA’s Breakthrough 2022: Artemis, 3D Printed Spacesuits and New Metal Alloys
With a dedicated multitude of followers worldwide and hundreds of thousands of people flocking to the Space Coast to see Artemis I launch on a 26-day mission around the Moon,...
Startup Accelerator: The 10 Most Active VCs in 3D Printing
The startup scene in 3D printing may be small compared to tech at large, but, as additive manufacturing (AM) increases in quality and importance, the number of firms to enter...
NASA Awards TROPICS CubeSat Mission to Rocket Lab
Spacecraft manufacturer Rocket Lab (Nasdaq: RKLB) has more big plans for the company as it expands its US presence. Known for its almost entirely 3D printed engines, the rocket company...