Copper Atoms Kept Closer to Combat Bacteria, New Approach Shown in Study

Researchers at the Tokyo University of Science in Japan are currently exploring an innovative approach that keeps copper atoms closer to fight against bacteria.

A Phys.org report specifically said the scientists are discovering such a strategy to boost the hydrogen peroxide or H202's vivo antibacterial activity. H202 is a commonly used disinfectant.

This finding of antibiotics was considered a major breakthrough in the field of medicine, which helped save many lives.

Regrettably, the common use has resulted in the fast evolution of bacterial strains that are highly resistant, that are threatening to bring back humanity to the beginning in combatting infectious diseases. 2

Copper-Containing Polymers

Although scientists are searching for new design ideas for antibacterial drugs, the general development of new agents is presently declining.

In the new study, Accelerated Redox Reaction of Hydrogen Peroxide by Employing Locally Concentrated State of Copper Catalysts on Polymer Chain, published in Macromolecular Rapid Communications, a research team led by Professor Hidenori Otsuka and Assistant Professor Shigehito Osawa reported their successful enhancement of H202 activity through the use of cautiously tailored polymers that contain copper.

In a similar report, Pharma Sources said, to understand the researchers' method, it is important to know the manner H202 is acting to combat bacteria in the first place, as well as the role played by copper.

Essentially, H202 can be decomposed into a hydroxyl radical or OH, and a hydroxide anion or OH-, the first-mentioned is highly poisonous to microbes as it is readily destroying certain biomolecules.

Getting Copper Atoms Close Enough Together

In its initial state of oxidation, Copper, also identified as Cu(I), can catalyze H202's splitting into a hydroxyl radical and a hydroxide anion, turning into Cu(II) in the process by means of oxidation.

Inquisitively, H202 can catalyze, too, the reduction of Cu(II) to Cu(I), although only if such a reaction is in some way facilitated. One approach that can be achieved is to have copper atoms get close enough together.

Nonetheless, when employing Cu(II)-containing complexes liquefied in a solution, the only way for them to get close together is by unintentionally bumping into each other, which necessitates an extremely high copper concentration.

The researchers discovered a workaround to this particular tissue by drawing inspiration from cellular chemistry; as Dr. Osawa said, in living organisms, copper is forming complexes with proteins to effectively catalyze redox reactions.

Tyrosinase, for example, comprises two copper complex areas in close proximity to each other, which is facilitating the formation of reaction intermediates between the copper complexes and oxygen species.

The researchers thought they could leverage this mechanism type in artificially produced polymers with copper complexes, even if dispersed in a solution.

DPA-Copper Complexes

With this notion, the scientists developed a long polymer chain with DPA or dipicolylamine as copper-containing complexes.

The Organic & Biomolecular Chemistry journal describes DPA as a distinctive structural switching component for helical peptides.

As specified in the said Phys.org report, these DPA-copper complexes were attached as "pendant groups" to a long polymer backbone.

When such polymers are dispersed in a solution, the CuII atoms in the pendant groups are retained in close proximity and locally high densities, massively increasing the probabilities that two of them will be close enough to be reduced by H202 to Cu(I).

Through numerous experiments, the researchers demonstrated that the use of such tailored polymers led to higher catalytic activity for the separation of H202, leading to more OH even for lower copper concentrations.

Further tests through the use of Escherichia coli cultures, as explained in the National Library of Medicine, revealed that these polymers substantially improved H202's antibacterial potential.

Related information about copper as an antimicrobial is shown on KSAT 12's YouTube video below: