Streptococcus pyogenes (S. pyogenes) and Staphylococcus aureus (S. aureus) are exotoxin-producing families of bacteria that can cause a variety of infectious diseases including sepsis, pneumonia, wound and skin and soft tissue infections, bacterial conjunctivitis, cellulitis, and endocarditis. If not treated properly, these infections could lead to toxic shock syndromes (TSS). Symptoms of TSS include high fever, hypotension, diffuse erythematous rash, and multiple organ dysfunction, which may rapidly progress to severe and intractable shock, septic shock. Mortality from staphylococcal TSS is less than 3% while the mortality from streptococcal TSS is ~20 to 60% despite aggressive therapy. Both bacteria families are included on WHO’s first ever list of antibiotic-resistant “priority pathogens” published in February, 2017. This list is a catalogue of 12 families of bacteria that pose the greatest threat to human health.
Cellics is developing biomimetic red blood cell membrane coated Nanosponges to absorb the toxins secreted by S. pyogenes or S. aureus to improve patients’ health and save lives. The virulence factors of these two strains of bacteria include secreting pore-forming toxins (PFTs) that create unregulated pores in the membrane of targeted cells and are frequently cytotoxic. The RBC membrane coated nanoparticles, which consist of a poly (dl-lactic-co-glycolic acid) (PLGA) nanoparticle core coated with RBC membrane, can be used as a biomimetic nanosponge to absorb the hemolytic PFTs holistically in vivo and thus divert the toxins away from their cellular target. As a result, these biologically inspired nanosponges present a detoxification treatment that can potentially treat the infectious diseases caused by S. pyogenes or S. aureus. This new approach can potentially treat both antibiotic susceptible and resistant infections caused by these two families of bacteria.
Cellics is developing different products based on the RBC Nanosponge platform to treat these infectious diseases:
- Parenteral injections to treat sepsis/TSS, cellulitis, pneumonia, or endocarditis
- Topical treatment for skin and soft tissue infections
- Ophthalmic administration to treat bacterial conjunctivitis
- RBC Nanosponge loaded hydrogel for would healing
Schematic of nanosponges absorbing toxins secreted by pathogenic bacteria, therefore interfering with bacterial virulence and/or cell-to-cell signalling pathways. Such anti-virulence approach is compelling as it may pose less selective pressure for the development of bacterial resistance than traditional strategies, which are aimed at killing bacteria or preventing their growth.