Hi-Tech Wound Dressings
August 1, 2014
A team of researchers from the Łódź University of Technology in central Poland has developed an innovative method for the production of special hydrogel dressings for hard-to-heal wounds. The dressings are based on a natural biopolymer called bionanocellulose. They are produced using a strain of the Gluconacetobacter xylinus bacteria.
Dressings made from this material can be used to treat first- and second-degree burns, bedsores, trophic ulcers and non-healing wounds in diabetic patients.
Bionanocellulose can also be used in other medicinal products such as implants and cell culture “scaffolds” as well as in cosmetics, say the researchers, who are led by Prof. Stanisław Bielecki, rector of the Łódź University of Technology.
The researchers say they have deciphered the first genome of the Gluconacetobacter xylinus strain of bacteria, which produces bionanocellulose. This strain of bacteria has many applications in the food industry, the chemical industry and medicine.
Bacterial cellulose is a product that meets all modern-day requirements for hydrogel materials, according to Bielecki. It is biocompatible, sterile, porous, flexible, reduces pain, and protects the skin from secondary infection. It also protects patients against loss of body fluids. It is a kind of “water jacket” allowing the wounds it covers to grow a new epidermis without scabbing and hypertrophic scarring, Bielecki says.
“We worked on this strain and it produced our bionanocellulose dressings, which are called CelMat,” says Bielecki. “Moreover, we were able to decipher the genome of the bacteria. Thanks to this, it is possible to better control the process of producing the biopolymer and improve its efficiency.”
The researchers use a genetically unmodified strain of the Gluconacetobacter xylinus bacteria. They are studying it at the molecular level to learn more about its possibilities and increase its efficiency.
The bionanocellulose produced by the Łódź researchers is of high purity, non-toxic, flexible, biocompatible, and mechanically resistant. It is a perfect dressing material for the treatment of hard-to-heal wounds, including burns or those accompanying so-called diabetic foot. Production is cheap, based on biodegradable raw materials and therefore environmentally friendly.
Molecular studies make it possible to expand the range of products from bionanocellulose useful in other areas of medicine.
Working in collaboration with the Genomed company from Warsaw, the Łódź researchers, who hail from the Institute of Technical Biochemistry at the University of Technology, deciphered the sequence of the genome of the first strain of the Gluconacetobacter xylinus bacteria producing bionanocellulose. The sequence of the genome of a similar bacterium was first described two years ago by Japanese researchers, but that bacterium did not produce cellulose.
Production of bionanocellulose according to the method developed by the Łódź scientists will be launched soon by the BowilBiotech company in the coastal Polish town of Władysławowo.
Bionanocellulose is a biopolymer produced naturally by plants and microorganisms. The most efficient producer of bionanocellulose is the Gluconacetobacter xylinus strain of bacteria. In nature, these bacteria are found in certain foods, especially fruit, and they are also present in sour cucumbers. In the Far East, they are used for the production of biofilm, or membranes composed of polysaccharides.
Bacterial cellulose has unique characteristics, including high hydrophilicity; it is not cytotoxic and has remarkable biocompatibility. This means that the human body does not reject it when it is implanted; nor does it cause allergies. This is rare among polymers used in medicine. This is why this material is so attractive, especially for regenerative and restorative medicine. It is 96 percent made up of water, and the remainder is sugars, or pure glucose chains woven together into nano-scale fibers.
The first clinical trials have produced excellent results: 40 percent faster healing of burns of different degrees. The scientists have just completed research into the external applications of bionanocellulose. Now they are working on using it for hernia mesh implants, and scaffolds for various types of cells that can complement some solid parts of the body such as cartilage or bone.
The dressings have been tested by patients treated in a specialized burn treatment center in Siemianowice Śląskie in southern Poland, and in medical universities in Łódź and Gdańsk. The next generation of products on which the team led by Bielecki is working involves three-dimensional items, chiefly for use as prostheses, implants and cell culture scaffolds.
Before the research is completed, the researchers want to carry out a number of chemical, biological and physical analyses, and they also have to examine the mechanical properties of the fibers produced. It is necessary to accurately determine the size of the dressing or implant in order to laparoscopically introduce it into the body.
“Our product should have a clearly defined mechanical strength, flexibility and water absorption level, so that we can successfully attach it to an organ. This is why we work with doctors of various specialties, such as soft surgery, orthopedics, neurosurgery and cardiology,” says Bielecki.
The project would not be possible without uncovering the secrets of the genome of the bacteria that produce bionanocellulose. The researchers set out to find out what determines the efficiency of biosynthesis and crystallization. They performed their genomic studies together with the Genomed company, discovering a number of molecular pathways, or assemblies of proteins that influence the process of how cellulose is produced. Knowing the biological mechanisms, they can manipulate the production process at the molecular level. This will allow them to achieve better, cheaper biocompatible materials for medical applications within a shorter time and many other new products with previously unknown applications.
Bielecki has co-authored several books on bionanocellulose. His team plans to hold a scientific symposium on nanotechnology in the coastal city of Gdańsk next year.
and Danuta K. Gruszczyńska