CN115581794B - Directional imbibition chitosan composite sponge and application thereof - Google Patents

Abstract

The invention provides a chitosan composite sponge for directional liquid absorption and application thereof. The chitosan composite sponge comprises a plurality of carboxylated chitosan hollow yarns arranged along the same direction and chitosan freeze-dried bodies filled inside and outside the carboxylated chitosan hollow yarns or only filled outside the carboxylated chitosan hollow yarns, so that the chitosan composite sponge absorbs liquid along the axial direction of the carboxylated chitosan hollow yarns and simultaneously expands along the radial direction of the carboxylated chitosan hollow yarns. According to the invention, the carboxylated chitosan hollow yarn is used as a sponge reinforcing body and a directional liquid absorption guide body, the wall layer has hydrophilicity, the hollow structure of the core layer has a wicking function, so that moisture can be transported along the axial direction of the carboxylated chitosan hollow yarn, and the carboxylated chitosan hollow yarn is mainly expanded along the radial direction of the carboxylated chitosan hollow yarn after being absorbed, so that the carboxylated chitosan hollow yarn can be rapidly absorbed and expanded to block a wound when used for hemostasis, and high-efficiency hemostasis is realized. In addition, the carboxylated chitosan hollow yarn has higher strength, is distributed in the chitosan sponge body, and the carboxyl can generate electrostatic action with the amino to form a crosslinked structure, so that the strength of the composite sponge is improved.

Description

Directional imbibition chitosan composite sponge and application thereof

Technical Field

The invention relates to the technical field of medical sponges, in particular to a chitosan composite sponge for directional liquid suction and application thereof.

Background

Uncontrollable traumatic hemorrhage is common in emergencies such as war, natural disasters, traffic accidents, surgery, etc., and life is endangered if the blood loss reaches 30% or more of the whole body blood in a short time. Therefore, rapid hemostasis in a short period of time is important to save lives of wounded persons when uncontrolled bleeding occurs. Therefore, the development of the biomedical material which has the advantages of high hemostatic speed, good biocompatibility and in vivo degradation has very important significance and application prospect.

In recent years, medical absorbable hemostatic sponges for use in the body have attracted great attention from the medical community and industry of various countries. The sponge needs to meet the following conditions: 1. has good biocompatibility, cell compatibility and tissue compatibility. 2. Has good biodegradability. The medical sponge is gradually degraded into low molecular weight compounds or monomers in the processes of hydrolysis, enzymolysis and the like in a human body, and degradation products can be discharged out of the body or can participate in normal metabolism in the body to disappear, and the degradation products have no toxic or harmful effects on cells. 3. Has high directional liquid absorption and adhesiveness, so as to realize rapid hemostasis and reduce bleeding amount. 4. Has plasticity and certain mechanical strength to prevent rupture from affecting hemostatic effect during hemostasis.

The chitosan is a high molecular compound existing in plants in nature, can be decomposed into glucose by human alpha-amylase and finally metabolized into water and carbon dioxide, has the advantages of good biocompatibility and degradability, no toxic or side effect, no irritation, clear metabolism mechanism, no inflammation caused by deposition in the body, full absorption by the human body and complete and non-toxic decomposed products, is an ideal raw material for preparing the absorbable hemostatic material, and has wide application prospect in the biomedical field. Polylactic acid is also a novel biodegradable material. Chitosan sponge has been widely studied and applied to medical hemostasis in recent years, for example, patent CN201810976088.9 discloses a hemostatic sponge structure made of chitosan, hemostatic sponge layers are arranged on two side surfaces, a medicine carrying layer is arranged between the hemostatic sponge layers, the medicine carrying layer is bonded with the hemostatic sponge layers, and the medicine carrying layer is used for stopping bleeding by using the biocompatibility of the chitosan sponge and the hemostatic property of the medicine carrying layer. However, the method needs to additionally add a medicine loading layer, and hemostasis is realized through slow release of the medicine, so that the method is not suitable for rapid hemostasis of wounds with large bleeding amount, and the preparation method is complicated.

In view of the foregoing, there is a need for an improved directional absorbent chitosan composite sponge and application thereof to solve the above problems.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide the directional liquid-absorbing chitosan composite sponge and the application thereof, wherein carboxylated chitosan hollow yarns are used as a sponge reinforcing body and a directional liquid-absorbing guiding body, and the directional high liquid-absorbing chitosan composite sponge is obtained by freeze drying together with chitosan solution.

In order to achieve the aim of the invention, the invention provides a directional liquid-absorbing chitosan composite sponge, which comprises a plurality of carboxylated chitosan hollow yarns arranged along the same direction and chitosan freeze-dried bodies filled inside and outside the carboxylated chitosan hollow yarns, so that the chitosan composite sponge can absorb liquid in the axial direction of the carboxylated chitosan hollow yarns and expand in the radial direction of the carboxylated chitosan hollow yarns.

As a further improvement of the invention, the distance between the carboxylated chitosan hollow yarns is 0-2mm, the outer diameter is 0.4-1mm, the inner diameter is 0.2-0.5mm, and the outer diameter is larger than the inner diameter.

As a further improvement of the invention, the preparation method of the carboxylated chitosan hollow yarn comprises the following steps: and (3) dissolving the core-spun yarn with the cortex layer of carboxylated chitosan to remove the core layer, thus obtaining the carboxylated chitosan hollow yarn.

As a further improvement of the present invention, the method of dissolving and removing the core layer includes: taking chitosan fiber vitamin strips as a skin layer, taking polylactic acid filaments as a core layer, and performing ring spinning to obtain chitosan composite core-spun yarns; then carboxylation modification is carried out on the chitosan composite core-spun yarn; after the reaction is finished, washing with aqueous solution of sodium hydroxide/ethanol to remove the polylactic acid filaments; and then washing with ethanol/water mixed solution and ethanol in sequence, and drying to obtain the carboxylated chitosan hollow yarn.

As a further improvement of the present invention, the modifier used for the carboxylation modification is a carboxylic acid containing a double bond; the carboxylic acid containing double bond is one or more of acrylic acid, butenoic acid and pentenoic acid, preferably acrylic acid.

As a further improvement of the invention, the preparation method of the directional liquid-absorbing chitosan composite sponge comprises the following steps: arranging a plurality of carboxylated chitosan hollow yarns in a mold along the same direction, then injecting chitosan solution into the mold, and finally freeze-drying to obtain a primary chitosan composite sponge; washing the primary chitosan composite sponge with a sodium hydroxide/ethanol aqueous solution, then sequentially washing with an ethanol/water mixed solution and water until neutral, and then performing secondary freezing and freeze-drying to obtain the chitosan composite sponge.

A chitosan composite sponge capable of achieving directional liquid absorption comprises a plurality of carboxylated chitosan hollow yarns which are arranged in the same direction and chitosan freeze-dried bodies filled outside the carboxylated chitosan hollow yarns, so that the chitosan composite sponge can achieve the directional liquid absorption effect in the axial direction of the carboxylated chitosan hollow yarns.

As a further improvement of the invention, the chitosan composite sponge also comprises a plurality of pore canals which are arranged along the vertical direction of the carboxylated chitosan hollow yarns; the preparation method comprises the following steps:

taking core yarns with a core layer of polylactic acid filaments and a skin layer of carboxylated chitosan fibers as warp yarns, and weaving the polylactic acid yarns as weft yarns to obtain a woven fabric;

placing one or more layers of braided fabrics in a mould, then injecting chitosan solution into the mould, and finally freeze-drying to obtain primary chitosan composite sponge;

washing the primary chitosan composite sponge with a sodium hydroxide/ethanol aqueous solution, then sequentially washing with an ethanol/water mixed solution and water until neutral, and then performing secondary freezing and freeze-drying to obtain the chitosan composite sponge.

The application of the directional liquid-absorbing chitosan composite sponge is characterized in that the chitosan composite sponge is used for hemostatic materials.

The beneficial effects of the invention are as follows:

1. the chitosan composite sponge provided by the invention has directional liquid absorption, and the carboxylated chitosan hollow yarns are used as a sponge reinforcement body and a directional liquid absorption guide body, and are freeze-dried together with chitosan solution to obtain the directional high-liquid absorption chitosan composite sponge. Because the wall layer of the carboxylated chitosan hollow yarn has hydrophilicity, the hollow structure of the core layer has a wicking function, and the hydrophilicity of the chitosan sponge body in and around the core layer is relatively weak, so that moisture can be transported along the axial direction of the core layer; meanwhile, after the wall layer of the carboxylated chitosan hollow yarn absorbs water, the wall layer is mainly expanded along the radial direction of the carboxylated chitosan hollow yarn, so that when the carboxylated chitosan hollow yarn is used for stopping bleeding, a wound can be quickly blocked, and high-efficiency hemostasis is realized.

2. The carboxylated chitosan hollow yarn selected by the invention has higher strength, is distributed in the chitosan sponge body, and the carboxyl can generate electrostatic action with the amino to form a crosslinked structure; the molecular chains of the chitosan and the molecular chains of the carboxylated chitosan hollow yarn fibers are mutually entangled, so that the strength of the composite sponge is improved, and the rebound resilience is also obviously improved.

3. According to the directional liquid-absorbing chitosan composite sponge provided by the invention, the core layer is polylactic acid filaments, the sheath layer is core spun yarn of carboxylated chitosan fibers, which is used as a sponge reinforcing body and a directional liquid-absorbing guide body, and the core spun yarn is removed by alkali washing after the core spun yarn is freeze-dried together with a chitosan solution, so that the yarn in the sponge is of a hollow structure, and the liquid absorption amount can be improved.

Drawings

FIG. 1 is a schematic cross-sectional structure of a chitosan composite sponge with directional wicking.

FIG. 2 is a physical view of the tubular fabric of carboxyethyl chitosan in example 4.

FIG. 3 is an optical microscope image of a tubular fabric of carboxyethyl chitosan in example 4.

Fig. 4 is a physical diagram of the chitosan composite sponge prepared in example 4.

Fig. 5 is a cross-sectional electron microscope image of the chitosan composite sponge prepared in example 4.

Fig. 6 is a surface electron microscope image of the chitosan composite sponge prepared in example 4.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to specific embodiments.

It should be further noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and/or processing steps closely related to aspects of the present invention are shown in the specific embodiments, and other details not greatly related to the present invention are omitted.

In addition, it should be further noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 1, the chitosan composite sponge with directional liquid absorption provided by the invention comprises a plurality of carboxylated chitosan hollow yarns arranged along the same direction and chitosan freeze-dried bodies filled inside and outside the carboxylated chitosan hollow yarns, so that the chitosan composite sponge can absorb liquid along the axial direction of the carboxylated chitosan hollow yarns and expand along the radial direction of the carboxylated chitosan hollow yarns. Because the wall layer of the carboxylated chitosan hollow yarn has hydrophilicity, the hollow structure of the core layer has a wicking function, and the hydrophilicity of the chitosan sponge body in and around the core layer is relatively weak, so that moisture can be transported along the axial direction of the core layer; meanwhile, after the wall layer of the carboxylated chitosan hollow yarn absorbs water, the wall layer is mainly expanded along the radial direction, and after the chitosan sponge absorbs liquid, the wall layer is also mainly expanded along the radial direction due to the fact that the wall layer is axially bound by the carboxylated chitosan hollow yarn, so that when the wall layer is used for hemostasis, wounds can be blocked by rapid liquid absorption expansion, and high-efficiency hemostasis is achieved. In addition, the carboxylated chitosan hollow yarn has higher strength, is distributed in the chitosan sponge body, and the carboxyl can generate electrostatic action with the amino to form a crosslinked structure, so that the strength of the composite sponge is improved.

The carboxylated chitosan hollow yarns are arranged in layers or in a tubular shape, and the axial directions of the yarns are the same. When being in tube arrangement, the cylindrical composite sponge is convenient to directly prepare and can be directly used.

The preparation method of the directional liquid-absorbing chitosan composite sponge comprises the following steps: arranging a plurality of carboxylated chitosan hollow yarns in a mold along the same direction (when the carboxylated chitosan hollow yarns are arranged in multiple layers, the two ends of the yarns can be fixedly arranged, freeze-drying and forming are carried out, then cutting and the like to obtain a target product), then injecting chitosan solution into the mold, and finally freeze-drying to obtain the primary chitosan composite sponge; the primary chitosan composite sponge is washed with aqueous solution of sodium hydroxide/ethanol (the main purpose is to remove acetic acid in the chitosan solution to prevent the composite sponge from absorbing water and dissolving), then washed with mixed solution of ethanol/water and water in sequence until neutral, and then subjected to secondary freezing and freeze-drying to obtain the chitosan composite sponge. Preferably, a step freezing method is adopted, specifically: freezing in refrigerator at-21deg.C for 4-8 hr, taking out, freezing in refrigerator at-21deg.C for 4-8 hr, and freezing in freezer at-41deg.C for more than 12 hr.

Specifically, the distance between carboxylated chitosan hollow yarns is 0-2mm, preferably 0.1-1mm, more preferably 0.2-0.5mm; the outer diameter is 0.4-1mm, the inner diameter is 0.2-0.5mm, and the outer diameter is larger than the inner diameter. Through regulating and controlling the arrangement distance and the aperture of the carboxylated chitosan hollow yarns, the liquid absorption capacity and the strength of the composite sponge can be regulated and controlled to adapt to different requirements.

The preparation method of the carboxylated chitosan hollow yarn comprises the following steps: and (3) dissolving the core-spun yarn with the cortex layer of carboxylated chitosan to remove the core layer to obtain the carboxylated chitosan hollow yarn.

Wherein the method for dissolving and removing the core layer comprises the following steps: taking chitosan fiber vitamin strips as a skin layer, taking polylactic acid filaments as a core layer, and performing ring spinning to obtain chitosan composite core-spun yarns; then carboxylation modification is carried out on the chitosan composite core-spun yarn; after the reaction is finished, washing with aqueous solution of sodium hydroxide/ethanol to remove polylactic acid filaments; and then washing with ethanol/water mixed solution and ethanol in turn, and drying to obtain the carboxylated chitosan hollow yarn. Wherein, in the process of washing with sodium hydroxide/ethanol, polylactic acid is dissolved and removed, and carboxylated chitosan is converted into sodium carboxylate, thereby improving the subsequent crosslinking and hemostatic effects.

The modified substance adopted by carboxylation modification is carboxylic acid containing double bonds; the carboxylic acid containing double bond is one or more of acrylic acid, butenoic acid and pentenoic acid, preferably acrylic acid. The carboxyl modification specifically comprises: adding chitosan fiber into an ethanol solution of carboxylic acid containing double bonds, and reacting for 2-30h at 55-80 ℃; after the reaction is finished, washing the fiber to be strong alkaline by using a sodium hydroxide/ethanol aqueous solution, oscillating and washing the fiber to be neutral by using an ethanol/water mixed solution, washing the fiber by using ethanol for 3 times, and finally drying the fiber to obtain the carboxylated chitosan fiber.

The invention also provides a chitosan composite sponge capable of directionally absorbing liquid, which comprises a plurality of carboxylated chitosan hollow yarns arranged in the same direction and chitosan freeze-dried bodies filled outside the carboxylated chitosan hollow yarns, so that the chitosan composite sponge can produce a directional liquid absorbing effect in the axial direction of the carboxylated chitosan hollow yarns. The preparation method comprises the following steps: arranging core-spun yarns with a core layer of polylactic acid filaments and a skin layer of carboxylated chitosan fibers in a mold along the same direction, then injecting chitosan solution into the mold, and freeze-drying to obtain a primary chitosan composite sponge; then washing with aqueous solution of sodium hydroxide/ethanol, then washing with mixed solution of ethanol/water and water in sequence until the mixture is neutral, and then performing secondary freezing and freeze-drying to obtain the chitosan composite sponge. And (3) in the aqueous solution washing process of sodium hydroxide/ethanol, dissolving and removing the polylactic acid filaments in the core-spun yarn, so as to obtain the carboxylated chitosan hollow yarn.

In the chitosan composite sponge, the inside of the carboxylated chitosan hollow yarn is not filled with chitosan sponge body, namely the chitosan sponge body is still of a hollow structure, the yarn with the hollow structure has a wicking effect, so that the liquid absorbing capacity is improved to some extent, but the dissolution of the yarn in the weft direction can lead to the appearance of a plurality of smaller hole structures in the sponge, so that the strength is reduced to some extent.

Particularly, the chitosan composite sponge also comprises a plurality of pore canals which are arranged along the vertical direction of the carboxylated chitosan hollow yarns, so that the liquid absorption capacity can be further improved; the preparation method comprises the following steps:

taking core yarns with a core layer of polylactic acid filaments and a skin layer of carboxylated chitosan fibers as warp yarns, and weaving the polylactic acid yarns as weft yarns to obtain a woven fabric;

placing one or more layers of braided fabrics in a mould, then injecting chitosan solution into the mould, and finally freeze-drying to obtain primary chitosan composite sponge;

washing the primary chitosan composite sponge with a sodium hydroxide/ethanol aqueous solution, then sequentially washing with an ethanol/water mixed solution and water until neutral, and then performing secondary freezing and freeze-drying to obtain the chitosan composite sponge. And (3) in the aqueous solution washing process of sodium hydroxide/ethanol, the polylactic acid filaments and the polylactic acid weft yarns in the core spun yarns are dissolved and removed, so that carboxylated chitosan hollow yarns and pore channels in the weft direction are obtained.

The application of the chitosan composite sponge for directional liquid absorption is that the chitosan composite sponge is used as hemostatic material, and is especially suitable for in-vivo penetration injury. By rapid aspiration and expansion, the wound can be closed and rapidly coagulated, so that the hemostatic effect is excellent.

Example 1

The preparation method of the directional liquid-absorbing chitosan composite sponge comprises the following steps:

and (3) layering carboxylated chitosan hollow yarns (the yarn arrangement distance is 0.2 mm) in a mold along the same direction, then injecting chitosan acetic acid solution into the mold, and finally freeze-drying to obtain the primary chitosan composite sponge. Then, the acetic acid in the chitosan is removed by washing with aqueous solution of sodium hydroxide/ethanol, then the chitosan is washed with mixed solution of ethanol/water and water in turn until the chitosan is neutral, and then secondary freezing and freeze-drying are carried out to obtain the chitosan composite sponge. The preparation method of the carboxylated chitosan hollow yarn comprises the following steps:

taking chitosan fiber vitamin strips as a skin layer, taking polylactic acid filaments as a core layer, and performing ring spinning to obtain chitosan composite core-spun yarns; then, acrylic acid is adopted to carry out carboxylation modification on the chitosan composite core-spun yarn; after the reaction is finished, washing with aqueous solution of sodium hydroxide/ethanol to remove polylactic acid filaments; and then washing with ethanol/water mixed solution and ethanol in turn, and drying to obtain the carboxylated chitosan hollow yarn.

Example 2

The directional liquid-absorbing chitosan composite sponge is different from the embodiment 1 in that the preparation method comprises the following steps:

arranging core-spun yarns with a core layer of polylactic acid filaments and a skin layer of carboxylated chitosan fibers in a mold along the same direction, then injecting chitosan solution into the mold, and freeze-drying to obtain a primary chitosan composite sponge; then washing with aqueous solution of sodium hydroxide/ethanol, then washing with mixed solution of ethanol/water and water in sequence until the mixture is neutral, and then performing secondary freezing and freeze-drying to obtain the chitosan composite sponge. And (3) in the aqueous solution washing process of sodium hydroxide/ethanol, dissolving and removing the polylactic acid filaments in the core-spun yarn, so as to obtain the carboxylated chitosan hollow yarn.

Example 3

The directional liquid-absorbing chitosan composite sponge is different from the embodiment 1 in that the preparation method comprises the following steps:

taking core yarns with a core layer of polylactic acid filaments and a skin layer of carboxylated chitosan fibers as warp yarns, and weaving the polylactic acid yarns as weft yarns to obtain a layered braided fabric;

placing one or more layers of braided fabrics in a mould, then injecting chitosan solution into the mould, and finally freeze-drying to obtain primary chitosan composite sponge;

washing the primary chitosan composite sponge with a sodium hydroxide/ethanol aqueous solution, then sequentially washing with an ethanol/water mixed solution and water until neutral, and then performing secondary freezing and freeze-drying to obtain the chitosan composite sponge. And (3) in the aqueous solution washing process of sodium hydroxide/ethanol, the polylactic acid filaments and the polylactic acid weft yarns in the core spun yarns are dissolved and removed, so that carboxylated chitosan hollow yarns and pore channels in the weft direction are obtained.

Example 4

Compared with the embodiment 3, the directional liquid-absorbing chitosan composite sponge is characterized in that the core layer is polylactic acid filaments, the sheath layer is core spun yarn of carboxylated chitosan fibers and is used as warp yarn, and the polylactic acid yarn is used as weft yarn to be woven, so that a tubular woven fabric is obtained (shown in figures 2 and 3). The other points are substantially the same as those of embodiment 3, and will not be described here again.

The chitosan composite sponge obtained in this example is shown in fig. 4 to 6, and it can be seen that the inside of the chitosan sponge has a porous structure.

Comparative example 1

A chitosan sponge, as compared to example 1, except that it does not comprise carboxylated chitosan hollow yarns, the preparation method comprising: and (3) injecting chitosan acetic acid solution into the mold, and finally, freeze-drying to obtain the chitosan sponge.

Comparative example 2

A chitosan sponge, in contrast to example 1, differs in that carboxylated chitosan hollow yarns are replaced with carboxylated chitosan yarns. The other points are substantially the same as those of embodiment 1, and will not be described here again.

TABLE 1 results of Performance test of examples 1-4 and comparative examples 1-2

TABLE 2 Rabbit femoral artery hemostasis time and bleeding volume

Sample of	Hemostatic time(s)	Blood loss (g)
			Gauze with gauze	356±2.6	4.67±0.33
Comparative example 1	183±2.3	3.65±0.19
			Comparative example 2	165±3.5	3.05±0.21
Example 1	19±0.8	1.07±0.18
			Example 2	13±1.2	0.98±0.24
Example 3	12±1.3	0.85±0.17
			Example 4	10±0.6	0.79±0.21

As can be seen from Table 1, when the inside of the carboxylated chitosan hollow yarn was filled with the chitosan sponge, the liquid absorption amount and the saturated liquid absorption amount were lower than those of the non-filled chitosan sponge inside the carboxylated chitosan hollow yarn for 10 seconds, and the radial change rate and the liquid absorption amount change of the sponge before and after liquid absorption remained the same, but the tensile strength and the compressive strength were larger than those of the non-filled chitosan sponge inside the carboxylated chitosan hollow yarn. When the inside of the carboxylated chitosan hollow yarn is filled with the chitosan sponge, the wicking effect of the yarn is weaker, and the liquid absorption capacity of the yarn is lower than that of the carboxylated chitosan hollow yarn which is not filled with the chitosan sponge. The chitosan is filled in the hollow yarn, the contact area of the chitosan and the carboxylated chitosan is larger than that of the chitosan which is not filled in the hollow yarn, and the mutual entanglement part between the chitosan molecular chains and the molecular chains of the carboxylated chitosan hollow yarn fibers is more, so that the strength of the composite sponge is improved. Compared with the sponge reinforced by arranged yarns, the layered braided fabric and the tubular braided fabric reinforced sponge obtained by weaving have slightly higher liquid absorption capacity and radial change rate of the sponge before and after liquid absorption, so that the liquid absorption swelling and bleeding stopping performance are better; however, the mechanical properties are lower than the former, because the polylactic acid yarns in the weft direction of the fabric are washed away in the process of sponge alkali washing, and weft-direction pores are formed, so that the mechanical properties are reduced. The liquid absorption capacity and mechanical property of the sponges enhanced by the layered braided fabric and the tubular braided fabric are not obviously different, wherein the liquid absorption amount and strength of the sponges enhanced by the tubular braided fabric and the radial change rate of the sponges before and after liquid absorption are slightly improved.

The embodiment and the comparative example show that after the carboxylated chitosan hollow yarn is compounded in the chitosan sponge, the liquid absorption amount, the strength and the radial change rate are obviously improved, which proves that the carboxylated chitosan hollow yarn is more conducive to directional expansion after the sponge absorbs liquid, thereby facilitating the blockage of wounds. When the yarn is of a non-hollow structure, the improvement degree of the liquid absorption and the radial change rate is limited, which indicates that the carboxylated chitosan hollow yarn plays a remarkable role in directional liquid absorption and expansion in the chitosan sponge.

As can be seen from Table 2, the hemostatic time and the bleeding amount of the directional liquid-absorbing chitosan composite sponge prepared by the invention are obviously lower than those of the hemostatic gauze and the chitosan sponge on the market. When the non-hollow carboxylated chitosan yarn is selected, the hemostatic effect is not obvious, which indicates that the carboxylated chitosan hollow yarn can obviously improve the hemostatic effect of the chitosan sponge.

In summary, the chitosan composite sponge with directional liquid absorption and the application thereof provided by the invention take carboxylated chitosan hollow yarns as a sponge reinforcing body and a directional liquid absorption guiding body, and the carboxylated chitosan hollow yarns and chitosan solution are freeze-dried together to obtain the chitosan composite sponge with directional high liquid absorption, and when the sponge contacts a wound, the sponge can quickly absorb moisture in blood and generate radial expansion, so that the wound is blocked, and quick hemostasis is realized. The carboxylated chitosan hollow yarn has higher strength, is distributed in the chitosan sponge body, and can form a cross-linked structure through electrostatic action between carboxyl and amino, and the chitosan molecular chains and the molecular chains of the carboxylated chitosan hollow yarn fibers are mutually entangled, so that the strength of the composite sponge is improved, and the rebound resilience is also obviously improved.

The above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the technical solution of the present invention.

Claims (8)

1. The chitosan composite sponge is characterized by comprising a plurality of carboxylated chitosan hollow yarns which are arranged along the same direction and chitosan freeze-dried bodies filled inside and outside the carboxylated chitosan hollow yarns, so that the chitosan composite sponge can absorb liquid along the axial direction of the carboxylated chitosan hollow yarns and expand along the radial direction of the carboxylated chitosan hollow yarns;

the preparation method of the carboxylated chitosan hollow yarn comprises the following steps: the core-spun yarn with the cortex of carboxylated chitosan is subjected to a method of dissolving to remove the core layer, so that the carboxylated chitosan hollow yarn is obtained;

the method for dissolving and removing the core layer comprises the following steps: taking chitosan fiber vitamin strips as a skin layer, taking polylactic acid filaments as a core layer, and performing ring spinning to obtain chitosan composite core-spun yarns; then carboxylation modification is carried out on the chitosan composite core-spun yarn; after the reaction is finished, washing with aqueous solution of sodium hydroxide/ethanol to remove the polylactic acid filaments; and then washing with ethanol/water mixed solution and ethanol in sequence, and drying to obtain the carboxylated chitosan hollow yarn.

2. The directional absorbent chitosan composite sponge according to claim 1, wherein the distance between the carboxylated chitosan hollow yarns is 0-2mm, the outer diameter is 0.4-1mm, the inner diameter is 0.2-0.5mm, and the outer diameter is larger than the inner diameter.

3. The directional liquid absorbent chitosan composite sponge according to claim 1, wherein said carboxylated modification is carried out using a carboxylic acid having a double bond.

4. A directional absorbent chitosan composite sponge according to claim 3, wherein said carboxylic acid containing double bonds is one or more of acrylic acid, butenoic acid, pentenoic acid.

5. The directional absorbent chitosan composite sponge according to claim 4, wherein said carboxylic acid containing double bonds is acrylic acid.

6. The directional liquid absorbent chitosan composite sponge according to claim 1, wherein the preparation method of the directional liquid absorbent chitosan composite sponge comprises the following steps: arranging a plurality of carboxylated chitosan hollow yarns in a mold along the same direction, then injecting chitosan solution into the mold, and finally freeze-drying to obtain a primary chitosan composite sponge; washing the primary chitosan composite sponge with a sodium hydroxide/ethanol aqueous solution, then sequentially washing with an ethanol/water mixed solution and water until neutral, and then performing secondary freezing and freeze-drying to obtain the chitosan composite sponge.

7. The chitosan composite sponge is characterized by comprising a plurality of carboxylated chitosan hollow yarns which are arranged along the same direction and chitosan freeze-dried bodies filled outside the carboxylated chitosan hollow yarns, so that the chitosan composite sponge has a directional liquid absorption effect in the axial direction of the carboxylated chitosan hollow yarns; the chitosan composite sponge also comprises a plurality of pore canals which are arranged along the vertical direction of the carboxylated chitosan hollow yarns; the preparation method comprises the following steps:

taking core yarns with a core layer of polylactic acid filaments and a skin layer of carboxylated chitosan fibers as warp yarns, and weaving the polylactic acid yarns as weft yarns to obtain a woven fabric;

placing one or more layers of braided fabrics in a mould, then injecting chitosan solution into the mould, and finally freeze-drying to obtain primary chitosan composite sponge;

washing the primary chitosan composite sponge with a sodium hydroxide/ethanol aqueous solution, then sequentially washing with an ethanol/water mixed solution and water until neutral, and then performing secondary freezing and freeze-drying to obtain the chitosan composite sponge.

8. Use of a chitosan composite sponge for directional wicking according to any of claims 1 to 7, wherein the chitosan composite sponge is used for hemostatic materials.