U.S. patent application number 17/263264 was filed with the patent office on 2021-06-24 for crosslinked protein-based separation membrane and application thereof.
The applicant listed for this patent is SHAANXI NORMAL UNIVERSITY. Invention is credited to Facui YANG, Peng YANG.
Application Number | 20210187448 17/263264 |
Document ID | / |
Family ID | 1000005503434 |
Filed Date | 2021-06-24 |
United States Patent
Application |
20210187448 |
Kind Code |
A1 |
YANG; Peng ; et al. |
June 24, 2021 |
CROSSLINKED PROTEIN-BASED SEPARATION MEMBRANE AND APPLICATION
THEREOF
Abstract
A crosslinked protein-based separation membrane and application
thereof. The separation membrane is formed by attaching a
crosslinked protein nanomembrane to a porous membrane, the
crosslinked protein nanomembrane is formed by crosslinking a
two-dimensional nanomembrane which is formed by phase transition of
a protein with a crosslinking agent, the separation membrane
contains a dense surface layer and a support layer, the dense
surface layer is the crosslinked protein nanomembrane, and the
support layer is the porous membrane; the protein is any one of
lysozyme, bovine serum albumin, insulin, and .alpha.-lactalbumin;
the crosslinked protein-based separation membrane has a good
biocompability, may serve as a dialysis membrane for blood
purification, and has a higher retention ratio for large molecular
proteins.
Inventors: |
YANG; Peng; (Shaanxi,
CN) ; YANG; Facui; (Shaanxi, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHAANXI NORMAL UNIVERSITY |
Shaanxi |
|
CN |
|
|
Family ID: |
1000005503434 |
Appl. No.: |
17/263264 |
Filed: |
May 7, 2019 |
PCT Filed: |
May 7, 2019 |
PCT NO: |
PCT/CN2019/085848 |
371 Date: |
January 26, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01D 69/10 20130101;
B01D 71/44 20130101; B01D 67/0006 20130101; B01D 2325/02 20130101;
B01D 2325/04 20130101 |
International
Class: |
B01D 71/44 20060101
B01D071/44; B01D 67/00 20060101 B01D067/00; B01D 69/10 20060101
B01D069/10 |
Foreign Application Data
Date |
Code |
Application Number |
May 14, 2018 |
CN |
201810456238.3 |
Claims
1-14. (canceled)
15. A crosslinked lysozyme-based dialysis membrane, wherein the
dialysis membrane is formed by attaching a crosslinked lysozyme
nanomembrane to a PET nuclear track membrane, the crosslinked
lysozyme nanomembrane is formed by crosslinking a two-dimensional
nanomembrane which is formed by phase transition of a lysozyme with
a glutaraldehyde, the dialysis membrane contains a dense surface
layer and a support layer, the dense surface layer is the
crosslinked lysozyme nanomembrane, and the support layer is the PET
nuclear track membrane; a method of forming a lysozyme
two-dimensional nanomembrane by phase transition of the lysozyme
comprises: adjusting a pH value of a 10-100 mmol/L
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of tris(2-carboxyethyl) phosphine to 6.0-8.0 by using NaOH
to get an adjusted solution, then mixing the adjusted solution with
a 1-30 mg/mL 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic
acid buffered solution of the lysozyme in an isovolumetric manner
to get a mixed solution, spreading the mixed solution to a whole
surface of a substrate directly, incubating at room temperature for
2-6 hours, forming a layer of the lysozyme two-dimensional
nanomembrane on a gas-liquid interface of a liquid on the
substrate; a method of crosslinking the lysozyme two-dimensional
nanomembrane which is formed by phase transition of the lysozyme
with the glutaraldehyde comprises: transferring the lysozyme
two-dimensional nanomembrane to a glutaraldehyde aqueous solution
with a mass fraction of 0.2%-2% for crosslinking for 2-6 hours at
room temperature.
16. The crosslinked lysozyme-based dialysis membrane according to
claim 15, wherein a diameter of the PET nuclear track membrane is
25 mm, a thickness of the PET nuclear track membrane is 12 .mu.m, a
pore size of the PET nuclear track membrane is in a range of 1-10
.mu.m.
17. Use of the crosslinked lysozyme-based dialysis membrane in the
separation of mixed proteins according to claim 15, wherein the
mixed proteins are bovine serum albumin and insulin, or muscle
hemoglobin and insulin.
18. Use of the crosslinked lysozyme-based dialysis membrane in the
separation of mixed dyes according to claim 15, wherein the mixed
dyes are methyl blue and methyl orange, or methyl blue and
Rhodamine B.
19. Use of the crosslinked lysozyme-based dialysis membrane in the
removal of urotoxin according to claim 15, wherein the urotoxin is
any one of urea, creatinine, .beta.-microglobulin and indoxyl
sulfate.
Description
TECHNICAL FIELD
[0001] The present invention relates to a separation membrane, and
specifically, to a green and mild separation membrane with easy
preparation and a controllable pore size, and uses of the
separation membrane.
BACKGROUND
[0002] Due to the characteristics such as high separation
efficiency, no secondary pollution, and easy operation, the
membrane separation technology has been widely applied to
petrochemical engineering, sewage treatment, medicine and health,
food processing, and other fields currently. The membrane material
is one of the essentials of the membrane separation technology. At
present, the common membrane materials mainly include organically
synthetic polymers. However, the preparation method of polymer
membranes is complex; and generally, organic substances (such as,
protein, colloid and microorganism) are easily adsorbed in a feed
solution during separation; the protein nonspecific adsorption on
the surface of a membrane further causes negative effects, such as
blood coagulation while being in contact with blood, resulting in
reducing the flux and selection of the separation membrane.
Hemodialysis treatment is one of the common treatment means to
treat uremia patients. The purpose of the blood purification
membrane is to achieve exchange of substances mainly through
diffusion/convection principles, thus cleaning up metabolic wastes
and excessive moisture, and maintaining electrolyte in the body.
However, medium to large molecular toxins cannot be cleaned up by a
conventional hemodialysis membrane. Therefore, it is of practical
significance to develop a low-cost separation membrane with good
separation performances and easy preparation.
[0003] The selective separation membrane was prepared by
self-assembly of nanostructure materials has been a new attempt in
the field of separation membranes in recent years. Up to now, most
of the nanocomposite membranes with permselectivity have been not
manufactured in mass production for industrial application.
SUMMARY OF THE INVENTION
Technical Problem
[0004] The technical problem to be solved by the present invention
is to provide a crosslinked protein-based separation membrane and
application thereof directed to the defects of the prior art
mentioned above.
Technical Solution
[0005] To solve the above technical problem, the crosslinked
protein-based separation membrane is formed by attaching a
crosslinked protein nanomembrane to a porous membrane, the
crosslinked protein nanomembrane is formed by crosslinking a
two-dimensional nanomembrane which is formed by phase transition of
a protein with a crosslinking agent, the separation membrane
contains a dense surface layer and a support layer, the dense
surface layer is the crosslinked protein nanomembrane, and the
support layer is the porous membrane.
[0006] The above protein is any one of lysozyme, bovine serum
albumin, insulin, and .alpha.-lactalbumin. When the above protein
is a lysozyme, a method of forming a lysozyme two-dimensional
nanomembrane by phase transition of the lysozyme comprises:
adjusting a pH value of a 10-100 mmol/L
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of tris(2-carboxyethyl) phosphine to 6.0-8.0 by using NaOH
to get an adjusted solution; then, mixing the adjusted solution
with a 1-30 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of the lysozyme in an isovolumetric manner to get a mixed
solution, spreading the mixed solution to a whole surface of a
substrate directly; and incubating at room temperature for 2-6
hours to, forming a layer of the lysozyme two-dimensional
nanomembrane on a gas-liquid interface of a liquid on the
substrate.
[0007] When the above protein is any one of bovine serum albumin,
insulin, and .alpha.-lactalbumin, a method of forming a
two-dimensional nanomembrane by phase transition of the protein
comprises: adjusting a pH value of a 10-100 mmol/L
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of tris(2-carboxyethyl)phosphine to 4.0-6.0 by using NaOH
to get an adjusted solution, then mixing the adjusted solution with
a 1-30 mg/mL 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic
acid buffered solution of the protein in an isovolumetric manner to
get a mixed solution, spreading the mixed solution to a whole
surface of a substrate directly, incubating at room temperature for
2-6 hours, forming a layer of a protein two-dimensional
nanomembrane on a gas-liquid interface of a liquid on the
substrate.
[0008] The method of crosslinking the two-dimensional nanomembrane
which is formed by phase transition of the protein with the
crosslinking agent comprises: transferring the two-dimensional
nanomembrane to a crosslinking agent aqueous solution with a mass
fraction of 0.2%-2% for crosslinking for 2-6 hours at room
temperature; where the crosslinking agent is any one of
glutaraldehyde, Genipin, glutamine transaminase and
carbodiimide.
[0009] The above porous membrane is any one of a PET nuclear track
membrane, a PC membrane, a PP membrane, a PSF membrane, and a PTFE
membrane; and a pore size of the porous membrane is in a range of
0.22-10 .mu.m.
[0010] The crosslinked protein-based separation membrane of the
present invention may serve as a dialysis membrane or an
ultrafiltration membrane for use.
[0011] For use of the crosslinked protein-based separation membrane
of the present invention as a dialysis membrane in the separation
of mixed proteins, the mixed proteins are, for example, bovine
serum albumin and insulin, or muscle hemoglobin and insulin.
[0012] For use of the crosslinked protein-based separation membrane
of the present invention as a dialysis membrane in the separation
of mixed dyes, the mixed dyes are, for example, methyl blue and
methyl orange, or methyl blue and Rhodamine B.
[0013] For use of the crosslinked protein-based separation membrane
of the present invention as a dialysis membrane in the removal of
urotoxin by hemodialysis, the urotoxin is a toxin having a relative
molecular weight less than 500, such as urea, creatinine, and a
medium molecular toxin having a relative molecular weight in the
range of 500 to 20000, such as .beta.-microglobulin, parathormone,
leptin, renin and protein binding toxin indoxyl sulfate, and the
like.
[0014] Beneficial effects of the present invention are as
follows:
1. The separation membrane of the present invention is
densely-piled by oligomers of a protein, colorless and transparent,
and is a pure protein membrane. The thickness of the membrane can
be controlled according to the concentration of the protein, and
the pore size decreases to 1.8 nm from 3.4 nm with the increase of
the membrane thickness. 2. The separation membrane of the present
invention has good biocompatibility; and thus can serve as a
dialysis membrane for blood purification to clean up urea,
creatinine, and medium to large molecular toxins, indoxyl sulfate,
and the like; and moreover the separation membrane has higher
retention ratio to macromolecular proteins. Therefore, the
separation membrane is a more ideal dialysis membrane material. 3.
The separation membrane of the present invention can efficiently
separate different sizes of mixed proteins and mixed dyes, such as
bovine serum albumin, insulin, muscle hemoglobin and insulin,
methyl blue and methyl orange, methyl blue and Rhodamine B. 4. The
separation membrane of the present invention is easy to prepare on
a large scale, has the characteristics of low cost, low energy
consumption, environmental friendliness and the like, and is free
of the step complicatedness and environmental pollution problems in
traditional synthetic procedures of a polymer membrane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a diagram of a scanning electron micrograph of a
crosslinked lysozyme nanomembrane in Embodiment 1.
[0016] FIG. 2 is a planar diagram of a transmission electron
microscope (TEM) of the crosslinked lysozyme nanomembrane in
Embodiment 1.
[0017] FIG. 3 is a diagram of an atomic force microscope (AFM) of
the crosslinked lysozyme nanomembrane in Embodiment 1.
[0018] FIG. 4 shows pore size distribution of crosslinked lysozyme
nanomembranes with different thicknesses.
[0019] FIG. 5 shows the removal of urea, indoxyl sulfate,
creatinine and .beta.-microglobulin by a dialysis membrane obtained
from Embodiment 1.
DETAILED DESCRIPTION OF THE INVENTION
The Best Embodiment of the Invention
Embodiment 1
[0020] A pH value of a 60 .mu.L 50 mmol/L
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of tris(2-carboxyethyl) phosphine was adjusted to 7.0 by
using NaOH; and then, the adjusted solution was mixed, in an
isovolumetric manner, with a 60 .mu.L 2 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme evenly before directly spreading a resulting
mixture to a whole surface of a 18 mm.times.18 mm cover glass; and
the mixed solution was incubated at room temperature for 2 hours to
form a layer of lysozyme two-dimensional nanomembrane on a
gas-liquid interface of a liquid on the cover glass; the lysozyme
two-dimensional nanomembrane on the gas-liquid interface was
transferred to an glutaraldehyde aqueous solution having a mass
fraction of 1%, and then crosslinked for 2 hours at room
temperature to obtain a crosslinked lysozyme nanomembrane.
[0021] The above crosslinked lysozyme nanomembrane was attached on
a PET nuclear track membrane with a diameter of 25 mm, a thickness
of 12 .mu.m and a pore size of 10 .mu.m to obtain a dialysis
membrane with the crosslinked lysozyme nanomembrane as a dense
surface layer and the PET nuclear track membrane as a support
layer.
The Embodiments of the Invention
Embodiment 2
[0022] In this embodiment, 2 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme in Embodiment 1 was replaced with an
isovolumetric 4 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme; and other steps were the same as those of
Embodiment 1 to obtain a dialysis membrane.
Embodiment 3
[0023] In this embodiment, 2 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme in Embodiment 1 was replaced with an
isovolumetric 6 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme; and other steps were the same as those of
Embodiment 1 to obtain a dialysis membrane.
Embodiment 4
[0024] In this embodiment, 2 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme in Embodiment 1 was replaced with an
isovolumetric 8 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme; and other steps were the same as those of
Embodiment 1 to obtain a dialysis membrane.
Embodiment 5
[0025] In this embodiment, 2 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme in Embodiment 1 was replaced with an
isovolumetric 10 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme; and other steps were the same as those of
Embodiment 1 to obtain a dialysis membrane.
Embodiment 6
[0026] In this embodiment, 2 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme in Embodiment 1 was replaced with an
isovolumetric 20 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme; and other steps were the same as those of
Embodiment 1 to obtain a dialysis membrane.
Embodiment 7
[0027] In this embodiment, 2 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme in Embodiment 1 was replaced with an
isovolumetric 30 mg/mL
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of lysozyme; and other steps were the same as those of
Embodiment 1 to obtain a dialysis membrane.
[0028] The inventor performed SEM characterization on the
crosslinked lysozyme nanomembranes prepared in Embodiments 1-7; and
the results showed that the thicknesses of the corresponding films
were successively 50 nm (see FIG. 1), 60 nm, 90 nm, 100 nm, 120 nm,
220 nm and 250 nm; and the nanomembranes were densely-piled by 20
nm oligomers after phase transition of lysozyme (as shown in FIG. 2
and FIG. 3). The area of the prepared crosslinked lysozyme
nanomembrane was controlled by a PET with a pore size of 6 mm; the
membrane was made to float on 5 mL ultrapure water; and then 50
.mu.L 0.5 mg/mL PEG with different molecular weights was dropwisely
added on the membrane; then an UV-Vis absorption spectrum was used
to monitor the permeability of the solution standing for around 24
hours, and to analyze the pore size distribution of the membrane;
and the results were shown in FIG. 4. The pore size distribution of
the membrane was obtained by fitting the retention ratios of the
membrane for different molecular weights; and the pore size of the
membrane decreased to 1.8 nm from 3.4 nm with the increase of the
membrane thickness.
Embodiment 8
[0029] Use of the dialysis membrane of Embodiment 1 in the
separation of methyl blue and methyl orange, methyl blue and
Rhodamine B, muscle hemoglobin and insulin, bovine serum albumin
and insulin was specifically as follows:
a dialysis membrane was made to float on 5 mL ultrapure water; and
the membrane was separately dropwisely added with a 50 .mu.L
aqueous solution containing 50 mg/L methyl blue and 50 mg/L methyl
orange, a 50 .mu.L aqueous solution containing 50 mg/L methyl blue
and 50 mg/L Rhodamine, a 50 .mu.L aqueous solution containing 10
g/L muscle hemoglobin and 10 g/L insulin, and a 50 .mu.L aqueous
solution containing 10 g/L bovine serum albumin and 10 g/L insulin;
after the solution stood for 24 hours at room temperature, the
permeability of the solution was monitored by an UV Vis absorption
spectrum. The experimental results show that the dialysis membrane
can completely pass through molecules having a molecular diameter
of less than 2 nm; moreover, the methyl blue, bovine serum albumin
and muscle hemoglobin having a molecular diameter of more than 3 nm
and carrying negative charges can be completely intercepted; the
retention ratio of methyl orange is merely 0.3%, the retention
ratio of Rhodamine B is 1.4%, and the retention ratio of insulin is
22.6%. The diffusion rate of methyl orange is up to 606 nmol
cm.sup.-2 h.sup.-1, and the diffusion rate of Rhodamine B is 308
nmol cm.sup.-2 h.sup.-1. Therefore, the membrane can achieve the
rapid and effective separation from methyl blue and methyl orange,
methyl blue and Rhodamine, muscle hemoglobin and insulin, bovine
serum albumin and insulin.
Embodiment 9
[0030] Use of the dialysis membrane of Embodiment 1 in the removal
of urea, creatinine, .beta.-microglobulin and indoxyl sulfate was
specifically as follows:
the simulation solution was an aqueous solution containing 1 mg/mL
bovine serum albumin, 25 mg/L indoxyl sulfate, 40 mg/L
.beta.-microglobulin, 100 mg/L creatinine and 1.5 mg/mL urea; flow
velocity of the simulation solution and dialysis fluid (water) was
10 mL/min; and dialysis was conducted for 4 hours with a dialysis
membrane. The removal ratio of the dialysis membrane for bovine
serum albumin, indoxyl sulfate, .beta.-microglobulin, creatinine
and urea was tested. As shown in FIG. 5, the dialysis membrane can
intercept the macromolecular bovine serum albumin; and has better
removal effects for indoxyl sulfate, urea, .beta.-microglobulin,
and creatinine; and the removal ratios were respectively 33.1%,
82.2%, 50.3% and 81.3%.
Embodiment 10
[0031] A pH value of a 60 .mu.L 50 mmol/L
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of tris(2-carboxyethyl) phosphine was adjusted to 5.0 by
using NaOH; and then, the adjusted solution was mixed with a 60
.mu.L 5 mg/mL 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic
acid buffered solution of bovine serum albumin evenly before
directly spreading a resulting mixture to a whole surface of a 18
mm.times.18 mm cover glass; and the mixed solution was incubated at
room temperature for 2 hours to form a layer of bovine serum
albumin two-dimensional nanomembrane on a gas-liquid interface of a
liquid on the cover glass; the bovine serum albumin two-dimensional
nanomembrane on the gas-liquid interface was transferred to a
Genipin aqueous solution having a mass fraction of 1%, and then
crosslinked for 2 hours at room temperature to obtain a crosslinked
bovine serum albumin nanomembrane. The obtained crosslinked bovine
serum albumin nanomembrane was attached on a PC membrane with a
diameter of 25 mm, a thickness of 12 .mu.m and a pore size of 10
.mu.m to obtain a dialysis membrane with the crosslinked bovine
serum albumin nanomembrane as a dense surface layer and the PC
membrane as a support layer. The use of the dialysis membrane in
the removal of urea, creatinine, .beta.-microglobulin and indoxyl
sulfate was the same as that in Embodiment 9. The experimental
results show that the dialysis membrane can intercept the
macromolecular bovine serum albumin; and has better removal effects
for indoxyl sulfate, urea, .beta.-microglobulin, and creatinine;
and the removal ratios were respectively 44.2%, 90.2%, 60.4% and
88.6%.
Embodiment 11
[0032] A pH value of a 60 .mu.L 50 mmol/L
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of tris(2-carboxyethyl) phosphine was adjusted to 4.0 by
using NaOH; and then, the adjusted solution was mixed with a 60
.mu.L 2 mg/mL 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic
acid buffered solution of .alpha.-lactalbumin evenly before
directly spreading a resulting mixture to a whole surface of a 18
mm.times.18 mm cover glass; and the mixed solution was incubated at
room temperature for 2 hours to form a layer of .alpha.-lactalbumin
two-dimensional nanomembrane on a gas-liquid interface of a liquid
on the cover glass; the .alpha.-lactalbumin two-dimensional
nanomembrane on the gas-liquid interface was transferred to a
glutamine transaminase aqueous solution having a mass fraction of
1%, and then crosslinked for 2 hours at room temperature to obtain
a crosslinked .alpha.-lactalbumin nanomembrane. The obtained
crosslinked .alpha.-lactalbumin nanomembrane was attached on a PP
membrane with a diameter of 25 mm, a thickness of 12 .mu.m and a
pore size of 10 .mu.m to obtain a dialysis membrane with the
crosslinked .alpha.-lactalbumin nanomembrane as a dense surface
layer and the PP membrane as a support layer. The use of the
dialysis membrane in the removal of urea, creatinine,
.beta.-microglobulin and indoxyl sulfate was the same as that in
Embodiment 9. The experimental results show that the use of the
dialysis membrane in the removal of urea, creatinine,
.beta.-microglobulin and indoxyl sulfate was the same as that in
Embodiment 9; and the dialysis membrane can completely intercept
the macromolecular bovine serum albumin; and has better removal
effects for indoxyl sulfate, urea, .beta.-microglobulin, and
creatinine; and the removal ratios were respectively 35.1%, 89.2%,
51.4% and 87.5%.
Embodiment 12
[0033] A pH value of a 60 .mu.L 50 mmol/L
2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffered
solution of tris(2-carboxyethyl) phosphine was adjusted to 6.0 by
using NaOH; and then, the adjusted solution was mixed with a 60
.mu.L 2 mg/mL 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic
acid buffered solution of insulin evenly before directly spreading
a resulting mixture to a whole surface of a 18 mm.times.18 mm cover
glass; and the mixed solution was incubated at room temperature for
2 hours to form a layer of insulin two-dimensional nanomembrane on
a gas-liquid interface of a liquid on the cover glass; the insulin
two-dimensional nanomembrane on the gas-liquid interface was
transferred to a 1-ethyl-(3-dimethylaminopropyl) carbodiimide
hydrochloride aqueous solution having a mass fraction of 1%, and
then crosslinked for 2 hours at room temperature to obtain a
crosslinked insulin nanomembrane. The obtained crosslinked insulin
nanomembrane was attached on a PSF membrane with a diameter of 25
mm, a thickness of 12 .mu.m and a pore size of 10 .mu.m to obtain a
dialysis membrane with the crosslinked insulin nanomembrane as a
dense surface layer and the PSF membrane as a support layer. The
use of the dialysis membrane in the removal of urea, creatinine,
.beta.-microglobulin and indoxyl sulfate was the same as that in
Embodiment 9. The experimental results show that the use of the
dialysis membrane in the removal of urea, creatinine,
.beta.-microglobulin and indoxyl sulfate was the same as that in
Embodiment 9; and the dialysis membrane can completely intercept
the macromolecular bovine serum albumin; and has better removal
effects for indoxyl sulfate, urea, .beta.-microglobulin, and
creatinine; and the removal ratios were respectively 32.1%, 83.6%,
50.1% and 86.1%.
* * * * *