The treatment of large wounds such as burns has always been a difficult problem in the medical field. Every year, countless burn patients suffer from wound infection and slow wound recovery. Especially in countries and regions with backward development and poor sanitary conditions, the problems caused by large wound infection are likely to lead to death. Therefore, it is very important to design a low-cost, easy-to-use and efficient therapy pathway for large-scale wounds. Thus, our Bacterial Cellulose(BC) composite scaffold: a kind of BC membrane cultured with allogenic engineered fibroblast ATCC CRL-2522(BJ) is a product that achieves the above requirements. Accordingly, we creatively considered combining the present treatment process with the large wound treatment technology in the hospital, to assist our products to achieve the best treatment effect.

Full-thickness skin defect wounds caused by various injury factors are very common in clinic. In the worldwide, there are about 100 million patients suffering from surgical wounds every year, and about 300 million patients have chronic wound treatment needs. On the one hand, accidental injuries in daily life such as burns and mechanical injuries may lead to serious wounds of the skin; on the other hand, the number of patients suffering from chronic wounds (mainly including venous ulcers, compressive ulcers and diabetes ulcers) has also increased yearly with the arrival of an aging society. Our proposed end users are the people who suffer from severe damage of dermis and have large and deep wounds.

We designed a three-layer structure to ensure the successful functioning of the BC membrane, including a cover hardware, another biological semi permeable membrane and our BC composite scaffold.

Our product BC membrane (with BJ) can efficiently fill wounds and promote wound healing. For more details: design.

Vacuum Sealing Drainage (VSD) is a treatment method that uses dressings, semi permeable membranes and negative pressure devices to seal and debridement wounds and promote wound healing¹. The conventional treatment method of opening the wound for daily debridement and changing drugs is easy to cause wound infection. However, VSD can use high negative pressure for debridement when the wound is closed, which reduces the possibility of infection. It is a very effective debridement method.

Considering that regular debridement is also required during the use of our products, it is undoubtedly an extremely effective treatment method to treat wounds in combination with VSD. Just as we need a wound sealing material for covering BC membrane, the biological semipermeable membrane used in VSD came into our sight at right time. This biological semipermeable membrane is widely used in hospital wound treatment and has the functions of waterproof and blocking bacteria. It can also play the role of semipermeable membrane in VSD to suck out wound exudate and necrotic tissue.

Therefore, we have chosen the biological semipermeable membrane as the second layer of our three-layer structure for wound treatment. The polyethylene alcohol hydrated seaweed salt foam in VSD can closely adhere to the tissue at the wound. The porous structure can cooperate with high negative pressure to clear the wound exudate and necrotic tissue. Our BC membrane also has a porous structure and can be evenly distributed at the wound, so that the negative pressure can reach every part of the wound evenly and form a comprehensive drainage.

We also have designed hardware to facilitate the formation of no light conditions. At the same time, the hardware can also help us to observe the wound situation in time and degrade the BC film through red and blue light control. The hardware is still in developing stage, and it is expected to achieve many functions such as remote control of BC membrane degradation, recording of wound conditions, and reminding patients for debridement through APP upgrade and improvement in near future.

We design our BC composite scaffold as a product that can help the rapid recovery of large wounds. The engineered BJ cells are freezed when not in use, and they will be resuscitated on the BC membrane before using. Then the BC composite scaffold will be implanted into large wounds with debridement. After implantation, we will cover a layer of sterile surgical membrane above the BC membrane as fixation, and install our hardware above the sterile surgical membrane. In the process of wound recovery, we will cooperate with the negative pressure technology to clean the wound to ensure that the wound is not infected.

1. Clean the wound.

2. Perform debridement according to the standard protocol.

3. Resuscitate engineered BJ cells on our BC scaffold.

4. Cut the BC composite scaffold to a proper size in a sterile environment without red and blue light, and completely cover the wound with the BC composite scaffold.

5. Inject Adeno-associated virus (type 6, AAV6) into the wound to make the wound margin cells secrete antibacterial peptides and cell growth factors.

6. Use degradable surgical suture to suture and fix BC composite scaffold to wound.

7. Seal the wound with sterile surgical membrane.

8. Fix the hardware at the wound to form a light free environment. Before installation, determine whether the device is started naturally, and whether the camera, red and blue light and lighting can be started normally without error. Start the hardware and observe the wound repair through the camera every day.

9. Use negative pressure technology to remove exudate regularly (at least once every 7 days), and decide whether to reinject recombinant AAV according to the wound condition. The operation method is to unlock the opening of the hardware in a sterile and no red and blue light environment, and remove the exudate in combination with the negative pressure device. In the meantime, we will decide whether to replace the second membrane depending on the condition of the wound.

10. When it is observed that the granulation completely covers the BC composite scaffold, turn on the blue light to degrade the BC membrane. When it is observed that the dermis is completely repaired, inject PCB into the wound and turned on red light to cause the idioctonia of engineered BJ cells.

11. Repeat the wound care process every week until the wound is epithelialized or reaches the desired wound state, then remove the hardware.

In the project design, we considered the multiple effects that BCAID may have on the human body, and used a fully safe implementation scheme in the project design to ensure that BCAID will not adversely affect the human body.

We use adeno-associated virus and Lentivirus as our vector to deliver DNA to target cells, their safety and clinical value has been repeatedly verified. And we use highly efficent red light suicide switch to control the life of our engineering cells. When they finish their tasks, we can easily kill them and make sure they won't be harmful to patient's body. What's more, BC will be degraded to glucose as the wound heals. So, nothing bad is left in the patient's body, nothing bad will be produced in the patient's body. It's completely safe.

For more details: safety.