Research has shown that scar formation is significantly reduced if the wound heals quickly. A burn wound that takes 21 days or more to heal has a greater than 70% risk of developing a significant scar, compared to a burn wound that heals in less than 10 days, which has only a 4% risk of developing a hypertrophic scar. Hence it is imperative to treat burns as soon as possible in order to reduce scarring and improve the patient's ability to move and function in society.
The development of skin cell transplant technology began in 1990, when Dr Wood was treating patients for serious burn injuries. Treating large burn injuries traditionally involves applying cultured skin in the form of sheets to the wound. The skin sheets are grown from skin cells obtained from the patient but usually take 14-21 days to produce. Dr Wood discovered that scarring could decrease if the wound could be treated within 10 days. She found that although skin sheets produced in 10 days often had holes in them, these areas healed faster than those treated with confluent sheets, and with less obvious scarring, because the cells had not achieved total confluence. And thus, a new technique was born.
The next step was to apply pre-confluent cells in a suspension even as early as five days before they formed a sheet, with the 'spray on' technique optimal. In this technique cells are harvested from the epidermis of a patient, and expanded in culture. They can be grown into a concentrated single cell suspension or a confluent cell sheet for application to the patient's wound. The healthy, living cells are cultured in a highly specialised laboratory by natural division processes, and then transplanted into the patient. As the original cells are taken from the actual patient instead of a donor (autologous cell culture), the body accepts these cells as its own, the tissue continues growing, and the healing process is optimised. The burn acts as an ideal culture medium, and sprayed on pre-confluent cells grow more quickly on the patient than in the laboratory. The advantage is that wounds or burns heal rapidly and leave less scarring if a skin graft is applied soon after an injury.
The CellSpray is another innovation that improves treatment for larger wounds. Also known as 'Spray on Skin,' the process involves using an aerosol delivery system to apply cultured skin cell suspensions evenly to larger and more massive wounds or burns.
Commercialisation of these techniques and technology is handled by the Australian commercial biotechnology company, Clinical Cell Culture or 'C3.' The C3 laboratory now cultures small biopsies into bigger volumes of skin cell suspensions in as few as five days, and this service is used by surgeons in Sydney, Auckland and Birmingham, UK. Cells can be delivered via aircraft and ready for use the next day in many cases. Royalties from licensing will be ploughed back into a research fund, called the McComb Foundation.
The intellectual property is protected by a combination of trade secrets and trademark processes, where employee confidentiality is paramount, and knowledge about C3's culturing processes is limited. The company has now reached an exciting stage with new products being rolled out and training of medical staff in other hospitals being undertaken. Recently, training has been completed for the Royal Hobart and Royal Brisbane Hospitals. ReCell is the latest innovation developed by C3, and having received WA Government funding support, will hopefully be on the market by the end of next year. It will come in a kit that will enable surgeons to harvest skin cells in theatre to allow them to treat small wounds in one operation. Cells are harvested from a small biopsy on a petri plate within 30 minutes. ReCell also allows pigment cells to be harvested, so it can be used in the treatment of small areas of pigment loss, like the size of two hands or a face.