Hydrogel-antibiotic
IBM has created a hydrogel with antibacterial physical properties
Andrey Vasilkov, Computerra-Online
The IBM Research division, while developing methods for managing materials at the atomic level, accidentally found an elegant solution to a long-standing medical problem (see the Breaking the bacteria barrier press release. New hydrogel born from semiconductor research may help save lives). Together with the Institute of Bioengineering and Nanotechnology in Singapore (IBN), IBM specialists have created a biocompatible hydrogel. Its antibacterial and antifungal properties are due not to chemical, but exclusively to physical effects.
The traditional development of antibacterial agents is a continuous process following the path of the sword and shield. Some time after the appearance of a new drug, strains resistant to it naturally arise.
A separate problem is the ability of many bacteria to form resistant films on catheters, drains, endoscopic equipment and other medical equipment. These stable associations of microorganisms of one or more strains have reliable mechanisms of self-defense and the spread of infection.
Stages of bacterial film development
Modern expensive endoscopic equipment is equipped with sophisticated electronics. It cannot be made disposable or subjected to harsh disinfection methods. Multilayer bacterial film reduces the effectiveness of gentle treatment carried out by antiseptic agents specially created for complex equipment. At the next examination or other medical manipulation, fragments of the bacterial film are separated and infect the next patient.
The front line in the protracted war between humans and pathogenic microorganisms runs through a network of medical institutions. Therefore, it is easier to catch diseases caused by resistant strains in them.
The Central Research Institute of Epidemiology of Rospotrebnadzor estimates the number of nosocomial infections in Russia at the level of 2-2.5 million cases per year. In the countries of the European Union and the USA, the bill also goes to hundreds of thousands and millions. Solving the problem of hospital infections eats up the lion's share of the budget.
According to a report by the US Centers for Disease Control and Prevention, the annual direct costs of preventing and treating nosocomial infections cost the treasury from 28.4 to $33.8 billion dollars.
IBM and IBN abandoned chemical methods of exposure and went a different way. In four years, a hydrogel based on multiblock copolymers with a predominance of positive charge on the surface of macromolecules was created jointly. Their self-assembly is carried out in an aqueous solution heated to human body temperature. The resulting hydrogel contains about 90% water and is characterized by high biological compatibility.
Composition of hydrogel and cylindrical cationic micelle (image: IBM Research)
It consists of block copolymers of polyethylene glycol (PEG), cetylpyridine chloride (CPC), right-(PDLA) and left-rotating (PLLA) isomers of lactic acid. Upon contact with the bacterial film, positively charged hydrogel macromolecules interact with the negatively charged surface of microbial cells. This leads to the destruction of their association and the death of most of the vegetative forms. Spore forms cannot be destroyed in this way, but the main scourge of hospitals and maternity hospitals is methicillin–resistant Staphylococcus aureus and a number of other dangerous pathogens do not form them.
Destruction of the bacterial film of the MRSA strain under the action of hydrogel
(photo: Institute of Bioengineering and Nanotechnology)
The outer surface of the membrane of somatic cells of the human body has a weak positive charge, so the hydrogel has practically no effect on them. It gradually undergoes biological decomposition and excretion. Initial studies indicate the absence of typical problems such as toxicity and accumulation effects.
When developing new technologies, their potential often opens up outside the initially chosen industry. It is necessary to have sufficient breadth of views to notice it in time and offer unexpected aspects of application.
Portal "Eternal youth" http://vechnayamolodost.ru30.01.2013