Regenerative dressings
Researchers at Northwestern University (USA), working under the guidance of Professor Guillermo Ameer, have developed a new device – a regenerative bandage that provides rapid healing of painful, poorly treatable ulcers without the use of medications.
A small scratch or wound is not a problem for most people. However, for patients with diabetes mellitus, an unhealed scratch can turn into an open wound or ulcer.
The reason for this lies in the fact that diabetes mellitus can lead to nerve damage, causing sensitivity disorders of the extremities. Therefore, people with diabetes sometimes do not notice small scratches or other damage and do not pay proper attention to them. Since the high glucose content in the blood leads to thickening of the capillary walls, the blood flow in them slows down, which complicates the healing process of such wounds. All this is an ideal scenario for turning a small wound into a non-healing ulcer that threatens amputation or even death.
The secret of the device developed by the authors is in laminin, a protein that is part of most body tissues, including skin. Laminin triggers signals in the cell that stimulate its differentiation, migration and attachment to other cells. The researchers found that a critical role in the wound healing process belongs to the laminin A5G81 segment, whose length is 12 amino acids.
According to Professor Amir, this segment has attracted attention for its ability to encourage cells to adhere, migrate and proliferate. The authors gradually shortened its sequence until they obtained a minimal fragment with the necessary properties. Using such a small fragment instead of a whole protein facilitates the synthesis of the active ingredient and reduces the cost of its production.
Regenerative dressing stimulates cell movement and proliferation. The green dots correspond to living cells penetrated into the hydrogel and stained with Calcein-AM dye.
Stained epidermal cells cultured on A5G81 peptide.
The researchers introduced A5G81 into a previously developed dressing made of a thermosensitive citrate-based hydrogel. The antioxidant properties of the hydrogel itself locally suppress inflammation in the damaged area. But the most important factor is the ability of the initially liquid material, when applied to the wound surface, to quickly fill in the defect and harden, taking the exact shape of the damage. This ability causes its advantage over the currently used collagen films and sponges, which do not fit tightly enough and can shift from the damage zone.
In addition, any bandages should be changed frequently, removing them from the wound, which in many cases leads to a violation of the healing surface and the appearance of secondary damage. The new material can be washed off with saline solution without violating the integrity of the forming tissue.
In a direct comparative study on a mouse model of diabetes mellitus, the new bandage increased the healing rate of diabetic ulcers by 33% compared to one of the most popular market analogues.
The authors hope to quickly introduce their development into clinical practice. This is quite possible, since the new bandage uses the body's own reserves, without releasing any pharmacological drugs or biologically active substances. In addition, their absence increases the safety of the approach, which did not cause any side effects in experimental animals. This greatly distinguishes it from the products available on the market, the mechanism of action of which is due to the content of the growth factor associated with the development of cancer.
In the near future, the authors plan to test their development on a larger preclinical model.
Article by Yunxiao Zhu et al. Potent laminin-inspired antioxidant regenerative dressing accelerates wound healing in diabetes published in the journal Proceedings of the National Academy of Sciences/
Evgenia Ryabtseva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of Northwestern University: Regenerative bandage accelerates healing in diabetic wounds.