Anti-bacterial applications of poly-N-acetylglucosamine nanofibers
Inventors
Vournakis, John N. • Finkielsztein, Sergio
Assignees
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Publication Number
US-9198928-B2
Publication Date
2015-12-01
Expiration Date
Abstract
Described herein are compositions comprising shortened fibers of poly-N-acetylglucosamine and/or a derivative thereof (“sNAG nanofibers”) and anti-bacterial applications of such compositions. The sNAG nanofibers may be formulated into compositions for the prevention and/or treatment of bacterial infections and diseases associated with such infections. Regimens employing such compositions are also described.
Core Innovation
The invention provides shortened poly-N-acetylglucosamine nanofibers (sNAG) for topical prevention and/or treatment of bacterial infections and bacterial-infection-associated diseases, including bacterial imbalance. The disclosed scope includes treating a bacterial infection in a subject and treating a disease associated with a bacterial infection or a bacterial imbalance.
The core materials are sNAG nanofibers produced by irradiation of poly-N-acetylglucosamine or a derivative thereof, where more than 50% of the sNAG nanofibers are no greater than 15 μm in length, or the irradiation reduces the average length of the nanofibers to less than 15 μm. The document further characterizes sNAG by microstructure and infrared spectrum similarity to non-irradiated material, and by a monosaccharide composition comprising N-acetylglucosamine monosaccharides and/or glucosamine monosaccharides with a high fraction of N-acetylglucosamine monosaccharides.
The disclosed functional concept is that sNAG does not have an effect on bacterial growth or survival of Staphylococcus aureus bacterial cultures in vitro. The document links reduced bacterial load and improved wound healing to innate immune signaling pathways including Akt1/Ets1-regulated defensin expression and Toll-like receptor expression.
Claims Coverage
The independent claims cover topical treatment using irradiated short sNAG nanofibers, with structural and compositional limits in some claim sets. Across these independent claims, the inventive features focus on irradiated short sNAG nanofibers, defined nanofiber length, defined structural/chemical characterization, a no-effect-in-vitro requirement for Staphylococcus aureus, and topical administration under exclusions of additional antibacterial agents and/or immunomodulators.
Topical treatment using irradiated sNAG nanofibers with short fiber length and no in vitro S. aureus growth/survival effect
Topically administering a composition comprising sNAG nanofibers where the sNAG nanofibers were produced by irradiation of poly-N-acetylglucosamine or a derivative thereof, with more than 50% of the sNAG nanofibers no greater than 15 μm in length or by an irradiation dose that reduces the average length to less than 15 μm, and wherein the sNAG nanofibers do not have an effect on bacterial growth or survival of Staphylococcus aureus bacterial cultures in vitro.
Wound site topical treatment using irradiated sNAG nanofibers without additional antibacterial agent
Topically administering a composition comprising sNAG nanofibers to a wound site in a subject diagnosed with a bacterial infection or displaying one or more symptoms, where the sNAG nanofibers were produced by irradiation of poly-N-acetylglucosamine or a derivative thereof to yield sNAG nanofibers with a more than 50% no greater than 15 μm length or with an irradiation dose that reduces the average length to less than 15 μm, and wherein the sNAG nanofibers do not have an effect on bacterial growth or survival of Staphylococcus aureus bacterial cultures in vitro, the composition does not comprise an additional anti-bacterial agent, and the composition is not administered in conjunction with an anti-bacterial agent.
Human topical treatment with irradiated short sNAG nanofibers having microstructure/structure/IR and mono-saccharide fraction criteria, and no in vitro S. aureus effect
Topically administering an effective amount of sNAG nanofibers to a human subject diagnosed with the bacterial infection or displaying one or more symptoms, wherein more than 50% of the sNAG nanofibers are less than 15 μm in length or the sNAG nanofibers were produced by irradiation of poly-N-acetylglucosamine or a derivative thereof with a dose of irradiation that reduces the average length of the sNAG nanofibers to less than 15 μm, wherein the sNAG nanofibers have the microstructure of the fibers, wherein the sNAG nanofibers comprise N-acetylglucosamine monosaccharides and/or glucosamine monosaccharides with more than 70% of the monosaccharides being N-acetylglucosamine monosaccharides, and wherein the sNAG nanofibers do not have an effect on bacterial growth or survival of Staphylococcus aureus bacterial cultures in vitro, wherein the bacterial infection is a skin infection, a gastrointestinal infection, a respiratory infection, a urinary tract infection, or a reproductive tract infection, and wherein the composition does not comprise an additional anti-bacterial agent or immunomodulator and is not administered in conjunction with an additional anti-bacterial agent or immunomodulator.
Across the independent claims, claim coverage centers on topical treatment using irradiated poly-N-acetylglucosamine-derived sNAG nanofibers that are predominantly short, are characterized by fiber microstructure and, in some claims, chemical/physical structure and monosaccharide composition, and are required not to affect Staphylococcus aureus growth or survival in vitro. Additional claim sets further restrict compositions by excluding additional antibacterial agents and/or immunomodulators and by targeting specific infection contexts such as bacterially infected wounds and specified infection-site categories.
Stated Advantages
Promotes cutaneous wound healing and defensin expression via Akt1/Ets1 signaling.
Reduces S. aureus load without direct bacterial growth inhibition.
Documented Applications
Treating a bacterial infection in a subject and a disease associated with a bacterial infection or a bacterial imbalance by topical administration of sNAG nanofibers.
Treating a bacterially infected wound site in a subject by topically administering a composition comprising sNAG nanofibers.
Treating a bacterial infection in a human subject, with infection types including skin infection, gastrointestinal infection, respiratory infection, urinary tract infection, or reproductive tract infection.
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