Patent Description:
Hydrogel products developed based on PEG derivatives have the advantages of good biocompatibility, non-toxicity, non-irritation, biodegradability, no need to be removed again after surgery in clinical application, and the products will gradually degrade with the recovery of patients and be metabolized by kidneys. At present, there are many kinds of hydrogel sealants developed based on PEG on the market, which are used for wound sealing, anti-adhesion, leakage sealing and the like. In recent years, the incidence of cerebrospinal fluid leakage (abbreviated as CSFL) has tended to increase with the increase in patients with spinal revision surgery and severe spinal dura mater adhesions and advanced age. Proper treatment of cerebrospinal fluid leakage is of great significance to achieve successful spinal surgery and prevent serious complications. In clinical use, because of the risk of nerve compression, the swelling ratio of the sealing hydrogel for spinal wound, spinal dura mater or cerebral dura mater should be as low as possible. In addition, for patients with other treatment needs such as inflammation, it is necessary not only to seal the wound but also to load drugs for treatment. In addition, the low-swelling PEG hydrogel used in the current technology has strong acidity and alkalinity, and there is adverse irritation to tissues during use. The currently available sealing hydrogel has a large swelling ratio and cannot be loaded with drugs or its sealing performance will be affected after loading drugs. Therefore, there is an urgent need for a drug-loaded hydrogel with low swelling for the sealing of the spine, cerebral dura mater and the like. <CIT> discloses a hydrogel composition which comprises, as constituents, both a tetra-armed polymer having a polyethylene glycol skeleton and a temperature-responsive tetra-armed polymer having a phase transition temperature and in which the polymers are crosslinked at the terminals through covalent bonds to form a network structure. <CIT> discloses a tissue sealant and a preparation method and application thereof, wherein the sealant mainly comprises hydrophilic raw material, nucleophilic raw material, a marker and physiological thinner, wherein the hydrophilic raw material mainly refers to the derivatives of polyethylene glycol and the nucleophilic raw material mainly refers to polyamino acid.

Directing at the problems existing in the prior art, the present invention provides a sealing hydrogel, and precursors for preparing the sealing hydrogel includes a first component and a second component.

The first component includes a compound A and a compound B; the compound A is a multiarm polyethylene glycol derivative, and the compound B is a polyarm copolyester of glycidyl isopropyl ether and ethyl glycidyl ether.

The second component includes an oligopeptide.

Preferably, both the compound A and the compound B contain the following group:
<CHM>.

Preferably, the compound A has a general structural formula of:
<CHM>.

Preferably, the sealing hydrogel has a swelling ratio in the three-dimensional direction greater than or equal to -<NUM>% and less than or equal to <NUM>%.

Preferably, in the compound B, in per <NUM> parts of ethyl glycidyl ether and glycidyl isopropyl ether, there are <NUM> to <NUM> parts of ethyl glycidyl ether included.

Preferably, the compound A and compound B have the same number of arms.

Preferably, the compound A and compound B have the same molecular weight.

Preferably, in per <NUM> parts of the mixture of compound A and compound B, there are <NUM> to <NUM> parts of compound A included.

Preferably, a molar ratio of the functional group
<CHM>
in the compound A and compound B to the functional group -NH<NUM> in the oligopeptide is <NUM>:(<NUM> to <NUM>).

Preferably, the first component further contains a color developer;.

Preferably, the number of residues of amino acids in the oligopeptide is from <NUM> to <NUM>; and preferably, the oligopeptide is trilysine.

Preferably, the second component further includes a bacteriostatic agent;.

Preferably, the first component and/or the second component is added with a drug;
further preferably, the drug is at least one of an anti-inflammatory drug, a hemostatic drug, an analgesic drug, an anti-rejection drug and an anti-tumor drug.

Preferably, the sealing hydrogel is prepared by the following method:.

preferably, the buffer a has a pH of <NUM> to <NUM>; and/or, the buffer b has a pH of <NUM> to <NUM>.

Preferably, in the mixed solution system, the oligopeptide has a concentration of <NUM> to <NUM>/mL;.

Preferably, the volume ratio of buffer a to the buffer b is <NUM>:(<NUM> to <NUM>).

The present invention also provides a method for preparing the sealing hydrogel according to the present invention, comprising the following steps:.

The present invention also provides a kit for preparing the sealing hydrogel according to the present invention, wherein a duplex syringe is arranged in the kit, the first component and second component are dissolved in buffer a and stored in syringe <NUM>; and the buffer b is stored in syringe <NUM>.

The present invention also protects the sealing hydrogel according to the present invention for use in methods of sealing of spinal dura mater and cerebral dura mater, leak sealing of other tissues, wound sealing and anti-adhesion.

The present application will be described in detail by the following additional technical features.

The present invention provides a sealing hydrogel, and precursors for preparing the sealing hydrogel includes a first component and a second component;.

The sealing hydrogel described in the present application, by using compound B in combination with compound A, and then further combined with the second component, can significantly reduce the swelling ratio, and the obtained hydrogel has weak acidity and alkalinity, and there is no adverse stimulation to tissues during use compared with the hydrogel prepared by using compound A and the second component alone in the prior art. Moreover, this hydrogel can be loaded with drugs, and the sealing property of hydrogel will not be affected after drug loading.

According to some preferred examples, both the compound A and the compound B contain the following group:
<CHM>.

According to some preferred examples, the compound A has a general structural formula of:
<CHM>.

According to some preferred examples, the sealing hydrogel has a swelling ratio in the three-dimensional direction greater than or equal to -<NUM>% and less than or equal to <NUM>%.

Because the above raw materials are selected, the hydrogel of the present invention can be prepared with a swelling ratio of more than or equal to -<NUM>% and less than or equal to <NUM>%, which can meet the requirements of clinical treatment with the risk of nerve compression, can be applied to the sealing of spinal wounds, spinal dura mater or cerebral dura mater, and has the advantages of high safety and good effect.

According to some preferred examples, in the compound B, in per <NUM> parts of ethyl glycidyl ether and glycidyl isopropyl ether, there are <NUM> to <NUM> parts of ethyl glycidyl ether ethyl glycidyl ether comprised, and the groups in the compound B are within the above range, so that the gel obtained has a small swelling ratio.

According to some preferred examples, the compound A and compound B have the same number of arms. Under the above conditions, the gel obtained has a small swelling ratio.

According to some preferred examples, the compound A and compound B have the same molecular weights. Under the above conditions, the gel obtained has a small swelling ratio.

According to some preferred examples, in per <NUM> parts of the mixture of compound A and compound B, there are <NUM> to <NUM> parts of compound A comprised. Under the above conditions, the gel obtained has a small swelling ratio.

According to some preferred examples, a molar ratio of the functional group
<CHM>
in the compound A and compound B to the functional group -NH<NUM> in the oligopeptide is <NUM>:(<NUM> to <NUM>). Under the above conditions, the gel obtained has a small swelling ratio.

Under the condition that the hydrogel of the present invention meets the above conditions, it is beneficial to further reduce the swelling ratio of the gel, and the swelling ratio in the three-dimensional direction can even reach about <NUM>% to <NUM>%.

According to some preferred examples, the compound A is one or more selected from <NUM>-arm polyethylene glycol succinimide succinate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide glutarate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide adipate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide heptanedioate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide sebacate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide succinate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide glutarate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide adipate (molecular weight <NUM> to <NUM> Da) <NUM>-arm-polyethylene glycol succinimide heptanedioate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide sebacate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide succinate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide glutarate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide adipate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-polyethylene glycol succinimide heptanedioate (molecular weight <NUM> to <NUM> Da) and <NUM>-arm-polyethylene glycol succinimide sebacate (molecular weight <NUM> to <NUM> Da).

According to some preferred examples, the compound B is selected from <NUM>-arm-copolyether succinimide succinate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide glutarate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide adipate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide heptanedioate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide sebacate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide succinate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide glutarate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide adipate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide heptanedioate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide sebacate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide succinate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide glutarate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide adipate (molecular weight <NUM> to <NUM> Da), <NUM>-arm-copolyether succinimide heptanedioate (molecular weight <NUM> to <NUM> Da), and <NUM>-arm-copolyether succinimide sebacate (molecular weight <NUM> to <NUM> Da);.

According to some preferred examples, the compound A is <NUM>-arm-polyethylene glycol succinimide adipate or <NUM>-arm- polyethylene glycol succinimide succinate, and the compound B is <NUM>-arm-copolyether succinimide adipate, <NUM>-arm-copolyether succinimide succinate or <NUM>-arm-copolyether succinimide glutarate.

According to some preferred examples, the first component also contains a developer;.

According to some preferred examples, the number of amino acid residues in the oligopeptide is from <NUM> to <NUM>, and the above selection can ensure that the prepared gel has a small swelling ratio and a fast gelation time.

Further preferably, the oligopeptide is trilysine.

According to some preferred examples, the second component further includes a bacteriostatic agent; and the second component of the present invention can ideally bind with the bacteriostatic agent, so that the obtained gel has certain bacteriostatic effect.

Further preferably, the bacteriostatic agent is a chitosan derivative. The bacteriostatic agent above is both antibacterial and safe for in vivo implantation.

More further preferably, the chitosan derivative is carboxymethyl chitosan, with the mass ratio of (<NUM> to <NUM>):<NUM> to the oligopeptide.

According to the present invention, the color developer is added into the first component, and the bacteriostatic agent is added into the second component, so that the gel reaction is not affected, and the gel formation is facilitated.

According to some preferred examples, drugs are added to the first component and/or the second component.

According to some preferred examples, the drug is at least one of an anti-inflammatory drug, a hemostatic drug, an analgesic drug, an anti-rejection drug and an anti-tumor drug.

According to some preferred examples, the oligopeptide of the present invention is prepared by a method including the following steps:.

According to some preferred examples, the pH of the buffer a is <NUM> to <NUM>, and the pH of the buffer b is <NUM> to <NUM>. When the pH of the buffer is in the above range, not only the forming characteristics of hydrogel is ensured, but also no damage to tissue cells is caused.

According to some preferred examples, in the mixed solution system, the oligopeptide has a concentration of <NUM> to <NUM>/ml;
According to some preferred examples, in the mixed solution system, the total concentration of compound A and compound B is <NUM> to <NUM>/mL, preferably <NUM> to <NUM>/mL.

When the effective components in the first component and the second component are within the above range, the swelling ratio and sealing strength of the gel can be ensured to be in the desired range.

According to some preferred examples, the volume ratio of the buffer a to the buffer b is <NUM>: (<NUM> to <NUM>).

According to some preferred examples, the buffer a contains one or more of phosphate, sodium chloride, potassium chloride, phosphoric acid and hydrochloric acid;
According to some preferred examples, the buffer b contains one or more of phosphate, carbonate, borate and sodium hydroxide.

The present invention also protects the method for preparing the hydrogel of the present invention, which comprises the following steps:.

The present invention also protects a kit for preparing the sealing hydrogel of the present invention, wherein a duplex syringe is arranged in the kit, and the first component and the second component are dissolved in buffer a and stored in syringe <NUM>; and the buffer solution b is stored in syringe <NUM>.

According to some preferred examples, during the use of the kit according to the present invention, drugs can be added to solution a or solution b, drugs that are acidic or neutral are added to solution a, and drugs that are stable in alkaline conditions are added to solution b.

The present invention also protects the sealing hydrogel for use in the sealing of spinal dura mater and cerebral dura mater, leak sealing of other tissues, wound sealing and anti-adhesion.

The present application will be further described in detail by the following examples, see Table <NUM> for details:.

The properties of the hydrogels in the above Examples were characterized, and the results are shown in Table <NUM>:.

It can be seen from the above Examples and Comparative Example that the present invention can indeed reduce the swelling ratio of the materials by the selection of raw materials for the preparation of hydrogel, especially the selection of compound B. Further, by optimizing the selection of compound B, the relative amounts used of compound A and compound B, the molecular weight and arm number and the ratio of functional groups in the first component and the second component, and the pH of the buffer and other conditions, the swelling ratio can be further reduced, the overall performance can be improved, and a hydrogel with low swelling ratio, high sealing strength and ideal for cell growth can be finally obtained.

The drug loading performance of the above Examples was tested, and the results are shown in Table <NUM>.

Drug loading: the ratio of each component is the same as that in Example <NUM>.

The loading amount of Methylprednisolone in Experiment Example <NUM> was the amount of commercially available single bottle, and Experiment Example <NUM> was to increase the loading amount of Methylprednisolone by <NUM> times, and then the results were tested, and there was no significant decrease after increasing the loading amount from the swelling ratio rate and sealing strength. Experiment Example <NUM> is the effect of loading one commercially available Diprospan injection. From the results, there is no significant effect on the performance of the gel itself after loading Diprospan, and the sealing hydrogel described in the present invention has a short drug release period.

Although the present invention has been described in detail by general description and specific embodiments, it is obvious to a person skilled in the art that some modifications or improvements can be made on the basis of the present invention.

Claim 1:
A sealing hydrogel, wherein precursors for preparing the sealing hydrogel comprise a first component and a second component;
the first component comprises compound A and compound B; the compound A is a multiarm polyethylene glycol derivative, and the compound B is a polyarm copolyester of glycidyl isopropyl ether and ethyl glycidyl ether;
the second component comprises an oligopeptide.