Some researchers from VTT technology research center in Finland have developed a kind of 3D printing material that can be applied to wound care by using nano cellulose. With the connection of electronic components and computers, this material can also achieve real-time monitoring and send relevant information about wound healing to relevant medical staff.

Biocompatibility of nano cellulose

As a natural bio based polymer, nano cellulose has excellent water balance and skin hydration properties, and has biocompatibility with human cells and tissues. Studies have found that nano cellulose has not found any rejection and inflammation in vivo. In addition, nanocellulose has excellent pH, temperature and salt stability, which can be used as a carrier for controlled release of therapeutic molecules. Because of these excellent characteristics, nano cellulose has been applied in wound antibacterial dressing, artificial graft and anti ultraviolet cosmetics.

Nano cellulose for 3D printing

3D printing is an effective method to manufacture personalized complex light structure. At present, the materials used for 3D printing include thermoplastic, metal, ceramic and so on. According to VTT, due to the challenge of printing paste, the application of biomaterials in 3D printing is quite limited. The researchers found that cellulose nanofibers are suitable for the development of 3D printing materials, which can improve the properties of bio based 3D printing paste: it has excellent water absorption capacity, so it can be made into enough viscous printing paste for 3D printing process (water content can be as high as 50%); it has high mechanical strength, and can have a positive impact on biodegradability; It can also be used as a substitute for other currently used 3D printing chemicals that may cause harmful emissions or allergies, such as resins, synthetic thickeners, enhancers and plastics.

3D printing nano cellulose wound care materials

The 3D printing wound care material prototype developed by VTT includes nano cellulose and printed electronic components for measuring wound healing. The measuring electrode is printed on the polyurethane nano cellulose film with silver ink, and the printing electrode is connected with the wireless flexnode reader developed by VTT, and the printed electrode is protected by laminated film. The outer layer of laminate is 3D wound care gel, which contains nano cellulose, alginate and glycerol active ingredients.

Through the use of nano cellulose, the wound care material created has better liquid absorption performance, which is three times more efficient than the alginate fiber dressing commonly used for wound care. By absorbing the water in the wound, the material can shorten the wound healing time. 3D printing wound care gel acts as a buffer between body and electronic components while promoting wound healing. Flexnode reader can transmit temperature or bio impedance data from the wound to the hospital computer to prompt the medical staff for signs of wound infection or other complications, so that they can adjust the patient's rehabilitation status according to the data.

The researcher said that although the developed 3D printing wound care materials have good application potential, there are still many challenges. Firstly, the flexible structure manufacturing based on biomaterials is challenging. With the loss of water, the material will become hard. Researchers are trying to improve the flexibility of the material by increasing the nonvolatile components in the matrix and using polymeric materials and plasticizers; Second, at present, nano cellulose has not been approved for medical use. It is expected that it will take some time for this 3D printing wound care product to enter the market. The team will try to use this bio based printing material in textiles, interior decoration and other fields first. In addition, the researchers will also focus on the application of natural antibacterial ingredients.