Sunflower Pollen Used as 3D-Printable Bio-ink
At Singapore’s Nanyang Technological University (NTU Singapore), a team of researchers has developed a new 3D-printable ink made from sunflower pollen. More environmentally friendly, durable, and affordable, this bio-ink could be used to manufacture parts for tissue engineering or drug delivery. One of the advantages of this pollen-based bio-ink is its ability to retain its shape once deposited on a bio-printer bed, making it easier to design the final product.
Bioprinting brings together all the techniques that make it possible to manufacture cellular structures with the same properties as natural tissues. Probably the most widely used process is extrusion: like an FDM printer, the bioprinter deposits the ink layer by layer, generally a hydrogel containing the cells. One of the biggest challenges with this technique is retaining the shape of this hydrogel. This is why printing media are needed: ink is traditionally deposited in a sort of matrix, which will be obsolete once the process is complete. Researchers at NTU Singapore, therefore, wanted to find an alternative that would no longer use a matrix and therefore minimize the waste associated with bioprinting.
Professor Cho Nam-Joon, the co-lead author of the study, explains: “Bioprinting can be a challenge because the material that the inks are made of is usually too soft, which means the structure can collapse during the print. By adjusting the mechanical properties of sunflower pollen, we have developed a pollen-based hybrid ink that can be used to print structures with good structural integrity. This is a significant achievement because the process of making pollen ink is sustainable and affordable. Since there are many types of pollen species with distinct sizes, shapes, and surface properties, pollen microgel suspensions could potentially be used to create a new class of environmentally friendly 3D printing materials.”
The Development of Sunflower Pollen Ink
The researchers first incubate sunflower pollen in an alkaline solution for 6 hours so that pollen microgel particles could form. Once this microgel is created, it is mixed with several hydrogels (alginate, hyaluronic acid, etc.). The team obtains its final ink which is ultimately a composite material. In order to test her new development, she 3D printed a tissue engineering scaffold consisting of 5 layers in 12 minutes. The researchers then deposited collagen to form anchors to which cells could attach themselves and grow. According to the team and the results obtained, the efficiency of seeding the cells was 96% to 97%. This pollen-based ink could therefore promote cell growth, an essential step in tissue regeneration.
Song Juha, a co-author of the study, adds: “Our findings may open new doors to custom flexible membranes that conform exactly to the contours of human skin, such as patches or face masks. These soft and flexible membranes are generally made on the basis of a flat geometry, resulting in problems such as fractures or poor fit when applied to large areas of skin, such as the face, or areas that experience frequent movements such as the joints. Using our pollen-based 3D printing ink, which is biocompatible, flexible, and inexpensive, we can make membranes that are adapted to the contours of human skin and capable of bending without breaking.”
Many applications are currently being tested by the NTU Singapore team, convinced of the possibilities offered by pollen and bioprinting. In any case, it is an affordable and sustainable method that could have a significant impact in the field of bioprinting. You can find the whole study HERE.
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Cover Photo Credit: Frenta/Adobe Stock