Methods and compositions for the prevention of and treatment of infections utilizing chitosan-derivative compounds
Inventors
Baker, Shenda • Wiesmann, William P.
Assignees
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Publication Number
US-9012429-B2
Publication Date
2015-04-21
Expiration Date
Abstract
The present invention is directed to the treatment and prevention of nosocomial infections or MRSA infections utilizing soluble chitosan or chitosan derivative compounds. These chitosan-derivative compounds, e.g., chitosan-arginine and chitosan-acid amines, exhibit bactericidal activity against bacterial pathogens, e.g., drug resistant bacteria such as Methicillin-resistant Staphylococcus aureus (MRSA).
Core Innovation
The invention relates to soluble chitosan and derivatized chitosan having formula (I), for the prevention and treatment of nosocomial and MRSA infections. In formula (I), n is an integer between 20 and 6000, and each R1 is independently selected from hydrogen, acetyl, and a group of formula (II), with at least 25% of R1 substituents being hydrogen, at least 1% being acetyl, and 4-30% being a group of formula (II).
The derivatized chitosan further includes permitted substituent chemistries where R2 is hydrogen or amino, optionally protected with Boc, and R3 may be C1-C6 alkyl, including amino- or guanidino-substituted, or an amino/guanidino-containing group. The disclosed side-chain analogs include arginine, lysine, and histidine analogs, and the composition is characterized by defined molecular-weight constraints and aqueous solubility in a pH range from 6.8 to 7.4.
The soluble/derivatized chitosan composition is administered at a concentration of 25-100 ppm and is described as substantially free of other impurities. In the disclosed use context, contacting or administering the composition inhibits bacterial growth and treats a methicillin-resistant Staphylococcus aureus infection or reduces MRSA load.
Claims Coverage
The provided claim coverage centers on one independent claim focused on a method of treating a methicillin-resistant Staphylococcus aureus (MRSA) infection or reducing MRSA load by administering derivatized chitosan of formula (I) at 25-100 ppm. The main inventive features are the constrained derivatized chitosan structure/composition and its use in the stated MRSA treatment or reduction method.
Derivatized chitosan of formula (I) with constrained R1 substituent distribution
Administering an effective amount of derivatized chitosan of formula (I) where n is an integer between 20 and 6000, each R1 is independently hydrogen, acetyl, or a group of formula (II), at least 25% of R1 substituents are hydrogen, at least 1% are acetyl, and 4-30% are a group of formula (II).
Administering derivatized chitosan at a defined concentration
Administering the derivatized chitosan of formula (I) at a concentration of 25-100 ppm to thereby treat an MRSA infection or reduce MRSA load.
Treatment or MRSA load reduction in a subject
A method of treating a methicillin-resistant Staphylococcus aureus (MRSA) infection or reducing MRSA load comprising administering the derivatized chitosan to a subject who has an MRSA infection.
Across the independent claim, the claimed method is anchored on administering a derivatized chitosan of formula (I) with a defined n value and an R1 substituent composition distribution, administered at 25-100 ppm, to treat MRSA infection or reduce MRSA load.
Stated Advantages
Treating a methicillin-resistant Staphylococcus aureus (MRSA) infection.
Reducing MRSA load in a subject.
Providing defined levels of MRSA-load reduction compared to the MRSA load before treatment.
Derivatized chitosan is aqueous soluble in a specified pH range (6.8 to 7.4).
Inhibiting bacterial growth.
Documented Applications
Prevention and treatment of nosocomial and MRSA infections.
A method of treating a methicillin-resistant Staphylococcus aureus (MRSA) infection or reducing MRSA load by administering derivatized chitosan of formula (I) to a subject having a MRSA infection.
Use of the composition in an antimicrobial context including MRSA and related Staphylococcus aureus strains.
Inhibiting bacterial growth when soluble/derivatized chitosan is contacted with clinical sample matrices, including MRSA contexts.
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