Scientists have created a unique material for wound treatment based on a system of polymeric microchambers. These structures slowly release the biologically active substances contained within them into the damaged tissue, thereby accelerating its healing and reducing scarring. The development paves the way for personalized treatment of complex injuries and chronic wounds, as it will allow doctors to adjust biochemical processes in the tissue depending on the stage of healing and the specific condition of the patient. The results of the study, supported by a grant from the Russian Science Foundation, were published in the Applied Materials Today journal.

The study involved scientists from the LIFT Research Center (Moscow), Skoltech, Saratov State Medical University named after V.I. Razumovsky (Saratov), Sechenov First Moscow State Medical University (Moscow), and Saratov Chernyshevsky State University (Saratov).

Tissue regeneration is a complex multifactorial biochemical mechanism that requires a precise balance and correct concentration of various chemicals for the successful restoration of damaged structures. One important factor in wound healing is the redox balance in tissues. For instance, in a healthy organism, strong oxidizers — reactive oxygen species, such as peroxide and hydroxyl radicals — provide antimicrobial protection and perform important regulatory functions: They stimulate cell division, collagen secretion, and promote blood vessel growth in the damaged area of the skin. However, in chronic diseases such as diabetes or pathologies of the circulatory system, the balance of oxidative processes is disrupted. In excess, reactive oxygen species damage cellular structures (membranes, DNA, and proteins), slow down tissue recovery, and enhance scarring. Insufficient levels of oxidative processes also negatively affect healing by reducing antimicrobial protection and disrupting cellular metabolism.

Modern wound treatment methods, including antiseptic dressings and hydrogels, although they partially accelerate healing, do not allow for precise maintenance of the redox balance in the wound environment. Moreover, the role of reactive oxygen species changes at different stages of healing, which complicates the task of creating an optimal environment. Therefore, new methods of wound care are needed throughout the entire recovery process.

Scientists have developed a wound coating that controllably releases ultra-small but therapeutically effective doses of bioactive substances into the wound cavity, thereby maintaining the required concentration of certain compounds. In particular, the authors demonstrated this using oxidative agents as an example.

Gleb Sukhorukov, Professor at Skoltech, Scientific Director of the LIFT Research Center, RSF grant recipient noted: “Speaking about coatings for therapeutic purposes, the scientific and medical communities face the problem of long-term retention of molecules. Our research group thought long and hard and eventually developed a microchamber technology where the substance is indeed retained for a long time. The advantage is that the drug is fixed inside the capsules in the polymer film, allowing for its sequential release into the wound. We expect to implement this technology into medical practice in less than three years. At the first stage, we managed to show that it does not cause harm. The next step is to prove a statistically significant therapeutic effect. I think within 1-2 years we will be able to confirm this.”

The researchers used a biodegradable polymer as a base, which should gradually break down in the wound, releasing the drugs. From this material, they formed highly ordered arrays of chambers, into which they “loaded” one of the bioactive substances — tannic acid or sodium percarbonate. The first compound is a natural antioxidant that reduces inflammation. The second serves as a source of hydrogen peroxide — an oxidizer that stimulates blood vessel growth and suppresses bacterial activity. The authors used these substances separately from each other (in different dressings) to precisely determine the effect of each.

As a support material and the surface that should directly contact the wound, the researchers used a thin functional hydrogel film based on gelatin, glycerol, and aminocaproic acid. This combination of substances gave the material hemostatic properties, ensured its elasticity, moisture retention capacity, and reliable adhesion to living tissues.

Laboratory tests confirmed that the developed system slowly releases bioactive substances from the chambers over 3-4 days. The authors emphasize that the speed of this process can be adjusted over a wide range by changing the composition or thickness of the polymer shell of the microchambers.

To test the material’s biocompatibility, scientists placed connective tissue cells — fibroblasts — on its surface. Under these conditions, the cells actively multiplied and maintained normal viability. Moreover, fibroblasts even penetrated into the cavity of the microchambers and formed a three-dimensional structure, indicating favorable conditions for healing.

Subsequently, the researchers tested the material on laboratory rats with artificially created wounds. The developed coatings — both with tannic acid and with sodium percarbonate — placed on the damaged skin significantly accelerated healing. For example, on the seventh day of the experiment, the area of wounds covered with the microchamber material was almost half the size of untreated wounds.

However, the mechanism of action of the materials with different bioactive substances differed. Thus, the coating with tannic acid accelerated tissue recovery by reducing oxidative stress and inflammation, while the coating with sodium percarbonate did so by accelerating blood vessel growth and providing an antimicrobial effect.

Furthermore, the authors demonstrated the possibility of building a hierarchical system with cascading release of various substances. Thus, the configuration of the material can be selected individually for patients depending on the type of wound and the stage of healing. For example, during the first week of healing, it would be possible to ensure the delivery of oxidative agents to stimulate the formation of a vascular network, and during the second week — an antioxidant to reduce inflammatory processes. The same can be implemented with other bioactive substances to correct the wound process, including growth factors and signaling molecules.

“Our colleagues in Moscow clinics often face problems that our created coating can solve. One of them is the development of infections when any implants and prostheses are introduced into the body. The second is the overgrowth of connective tissue after the implantation of stents in the trachea and other hollow structures in the body. Our material can reduce the risk of repeat surgeries needed to address these problems,” noted Senior Research Scientist Olga Sindeeva from the Skoltech Neuro Center.