Self-Assembling Peptide Nanofibrils Created to Combat Intracellular Bacterial Infections

Researchers have developed a new type of self-assembling peptide nanofibrils with unique properties that enable them to effectively destroy intracellular pathogenic bacteria. The results of this important study are published in the journal Science Advances.

What is the essence of the new approach?

Intracellular bacteria pose a serious medical challenge because they hide from the immune system and are often resistant to traditional antibiotics. To overcome these challenges, a group of scientists led by Dr. W. Yu developed peptide molecules capable of self-assembling into stable nanofibrils and possessing pronounced antimicrobial activity.

The peptides were carefully designed with a specific balance of hydrophobic and hydrophilic amino acid residues. It is this design that allows them to spontaneously form fibrous structures called nanofibrils. These structures are stable in biological environments and resistant to enzymatic degradation, which significantly increases their therapeutic potential.

Mechanism of action of nanofibrils

The researchers demonstrated that self-assembling nanofibrils:

1. They effectively penetrate infected cells, bypassing cellular barriers, thanks to an optimized combination of charged and hydrophobic amino acids.
2. They reach the intracellular space where bacterial pathogens, including resistant strains, are located.
3. They disrupt the integrity of bacterial membranes, leading to their rapid death.

An important feature of the new nanofibrils is that they have pronounced activity inside infected cells, whereas conventional antibiotics have difficulty reaching such bacteria and are less effective.

Research details and results

The experiments were conducted on cell cultures infected with intracellular bacterial pathogens (e.g. Listeria monocytogenes). The tests revealed:

• High antimicrobial efficacy of new peptides against intracellular pathogens.
• Minimal toxicity to host cells, demonstrating their safety for potential use.
• Resistance to degradation by body enzymes, which allows the use of nanofibrils in the form of therapeutic drugs with a prolonged effect.

Further studies using electron microscopy confirmed the formation of nanofibrils, and biochemical analyses showed that these structures are stable and have stable physicochemical characteristics.

Practical significance of the discovery

The developed nanofibrils represent a promising alternative to traditional antibiotics, especially in the fight against infections that are difficult to treat. They can be used:

• For the treatment of intracellular infections, including resistant strains of bacteria against which many antibiotics are ineffective.
• As a basis for the delivery of other drugs into cells, due to their ability to penetrate cell membranes.
• As part of complex therapy for severe infectious diseases such as tuberculosis, brucellosis, salmonellosis and other diseases caused by intracellular pathogens.

This approach can also be adapted to create new materials and coatings with antimicrobial properties for the prevention of hospital-acquired infections.

Future plans and prospects

In the future, the researchers plan to continue testing on animal models to confirm the effectiveness and safety of the nanofibrils in living organisms. In addition, work is underway to optimize the structure of the peptides for even more effective action against various strains of intracellular bacteria.

Thus, the creation of self-assembling peptide nanofibrils opens up a completely new direction in the development of antibiotics and biomedical materials. The approach based on controlled self-assembly of peptides demonstrates significant potential for the medicine of the future, especially in light of the growth of antibiotic resistance and new challenges of infectious diseases.