Patent application EP20172421A (EP), filed 2020-04-30
Publication number: EP3733755A1
Title: HOMOGENEOUS HYDROGELS FROM CHITOSAN OLIGOSACCHARIDE DERIVATIVES AND APPLICATIONS THEREOF
Abstract: [0001]    The invention concerns a process for the preparation of hydrogels from chitosan oligosaccharide derivatives and boric acid, which allows to obtain homogeneous hydrogels avoiding the formation of precipitates. In another aspect, a hydrogel obtainable from this process is described.
[0002]    The use of the hydrogels in the biomedical and pharmaceutical fields for applications such as viscosupplementation, as a substitute for the extracellular matrix, and as a drug delivery system are also described.
IPC codes: A61K  47/    36            A I
A61L  27/    20            A I
C08B  37/    08            A I
C08L   5/    08            A I
Claims: number: 1
text: A process for the preparation of a homogeneous hydrogel from chitosan oligosaccharide derivatives, said process having the steps of:
number: 2
text: A process for the preparation of a homogeneous hydrogel from chitosan oligosaccharide derivatives, said process having the steps of:
number: 3
text: A process for the preparation of a homogeneous hydrogel from chitosan oligosaccharide derivatives, said process having the steps of:
number: 4
text: A process for the preparation of a homogeneous hydrogel from chitosan oligosaccharide derivatives, said process having the steps of:
number: 5
text: The process according to any one of claims 1 to 4, wherein the homogenizing reagent is mannitol at a final concentration in the range from 1 to 1,000 mM, preferably the final concentration of mannitol being 16 mM.
number: 6
text: The process according to claim 5, wherein a buffer solution is added to the solution obtained from step a., preferably said buffer solution being added until a concentration ranging from 1 to 100 mM is obtained, more preferably said buffer solution being phosphate buffered saline (PBS 1x) at a concentration of 10 mM.
number: 7
text: The process according to any one of claims 1 to 6, wherein the pH of the solution of steps b., c. and f. are equal to pH 7.4.
number: 8
text: The process according to any one of claims 1 to 7, wherein the final concentration of the oligosaccharide chitosan derivative is in the range from 0.5% to 5% w/V, preferably in the range from 0.8% to 2% w/V, even more preferably the final concentration of the chitosan oligosaccharide derivative being 1% w/V.
number: 9
text: The method according to any one of claims 1 to 8, wherein the final boric acid concentration is in a range from 1 to 300 mM, preferably in a range from 6 to 50 mM, even more preferably the final boric acid concentration being 8 mM.
number: 10
text: The process according to any one of claims 1 to 9, wherein the final concentration of the homogenizing reagent is in the range from 1 to 1,000 mM, preferably the final concentration of the homogenizing reagent being in the range from 6 to 50 mM, preferably said homogenizing reagent being mannitol at a final concentration of 16 mM.
number: 11
text: The process according to any one of claims 1 to 10, said process having the steps of:
number: 12
text: A hydrogel of chitosan oligosaccharide derivatives, obtainable according to any one of claims 1 to 11, having a strain strength with non-linear stress-strain ratio up to 600%, wherein said hydrogel is stable at room temperature for at least 7 days.
number: 13
text: A hydrogel of chitosan oligosaccharide derivatives according to claim 12, for use as a medicament.
number: 14
text: A hydrogel of chitosan oligosaccharide derivatives according to claim 12, for use in viscosupplementation.
number: 15
text: Use of a hydrogel of oligosaccharide chitosan derivatives according to claim 12, to promote cell and tissue growth.
number: 16
text: A hydrogel of chitosan oligosaccharide derivatives according to claim 12, for use in the orthopedic field.
number: 17
text: A hydrogel of chitosan oligosaccharide derivatives according to claim 12, for use in the ophthalmic field.
Office action: search_report, dated 2020-11-04
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Final disposition: pending (2020-11-04)