Photo-thermal conversion wood-based hydrogel and preparation method thereof

Abstract

The invention discloses photo-thermal conversion wood-based hydrogel and a preparation method thereof in the technical field of nano materials and biological materials, and the preparation method comprises the following steps: synthesizing a conjugated polymer CP, dissolving the CP in THF, and adding DSPE-PEG2000 and hemin to obtain CP-Hemin nano powder; and compounding the CP-coated Hemin nano powder, flexible wood and PVA (Polyvinyl Alcohol) to obtain the wood-based hydrogel. The wood-based hydrogel provided by the invention has high photothermal conversion efficiency, can be rapidly heated under laser induction of a near-infrared second region, releases reactive oxygen free radicals at the same time, can be applied to photothermal therapy and photodynamic therapy, and has a prospect of being applied to the fields of catalysis, medical treatment and the like.

Description

Technical Field

[0001] The invention relates to the technical field of nanomaterials and biomaterials, and in particular to a photothermal conversion wood-based hydrogel and a preparation method thereof. Background Art

[0002] At present, the proliferation of drug-resistant bacteria has caused the effectiveness of antibiotics to plummet, so many methods have been developed to sterilize without producing drug-resistant bacteria. For example, photothermal and photodynamic therapy, this emerging method will not cause the production of drug-resistant bacteria, and can have a good killing effect on drug-resistant bacteria, thereby reducing the risk of infection and recurrence.

[0003] Photothermal therapy is a treatment method that uses materials with high photothermal conversion efficiency, injects them into the human body, uses targeted recognition technology to gather near tumor tissue, and converts light energy into heat energy under the irradiation of an external light source (usually near-infrared light) to kill bacteria or cancer cells.

[0004] Photodynamic therapy is a new method that uses photosensitive drugs and laser activation to inhibit bacteria and treat diseases such as tumors. Irradiating the lesion site with a specific wavelength can activate the photosensitive drugs that selectively accumulate in the lesion tissue, triggering a photochemical reaction to destroy the lesion. The photosensitive drugs in photodynamic therapy transfer energy to the surrounding oxygen to generate highly active singlet oxygen. Singlet oxygen can undergo oxidation reactions with nearby biomacromolecules, produce cytotoxicity and kill diseased cells. Compared with traditional therapies, the advantage of photodynamic therapy is that it can accurately and effectively treat, and the side effects of this therapy are also very small.

[0005] Hydrogel is a type of extremely hydrophilic three-dimensional network structure gel that swells rapidly in water and can retain a large volume of water without dissolving in this swollen state. Hydrogel is a commonly used wound dressing. Its water retention and drug loading rate are very suitable for wound use conditions and can inhibit bacteria and fight inflammation.

[0006] Flexible wood is a purely natural, non-toxic material with a wide range of sources and no pollution. It also has excellent mechanical properties, anisotropy and other functions. It can provide a certain mechanical stability for the hydrogel, allowing the hydrogel to adapt to more usage environments.

[0007] At present, there is no antibacterial wood-based hydrogel on the market that has both photothermal conversion and photodynamic properties. Summary of the invention

[0008] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a photothermal conversion wood-based hydrogel and a preparation method thereof. The wood-based hydrogel has a high photothermal conversion efficiency, can rapidly heat up under the induction of laser in the near-infrared second region, and releases reactive oxygen free radicals at the same time. It can be applied to photothermal therapy and photodynamic therapy, and has the prospect of being applied to fields such as catalysis and medicine.

[0009] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0010] In one aspect, the present invention provides a method for preparing a photothermal conversion wood-based hydrogel, comprising:

[0011] 4,8-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole, 4,8-bis[(2-et-hydroxyhexyl)oxy]-2,6-bis(trimethyltinyl)benzo[1,2-b:4,5-b']dithiophene and N,N-bis(4-bromophenyl)-N, N-dimethyl-[1,1'-b-phenyl]-4,4'-diamine were completely dissolved in methanol, and Pd2(dba)3 and P(o-tol)3 were added to react to obtain a conjugated polymer CP;

[0012] CP was dissolved in tetrahydrofuran (THF), and distearoylphosphatidylethanolamine-polyethylene glycol 2000 (DSPE-PEG2000) and hemin were added to react to obtain hemin-loaded CP nanopowder (CP@Hemin nanopowder);

[0013] The flexible wood was immersed in polyvinyl alcohol (PVA) solution, and CP@Hemin nanopowder was added for cyclic freeze-thaw treatment to obtain photothermal conversion wood-based hydrogel.

[0014] Furthermore, the molar ratio of the added 4,8-bis(5-bromo-4-(2-octyldodecyl)thiophene-2-yl)-benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole, 4,8-bis[(2-et-hydroxyhexyl)oxy]-2,6-bis(trimethyltinyl)benzo[1,2-b:4,5-b']dithiophene, N,N-bis(4-bromophenyl)-N, N-dimethyl-[1,1'-b-phenyl]-4,4'-diamine, Pd2(dba)3 and P(o-tol)3 is (8-12):(9-15):(0.6-0.12):(0.3-0.6):(3-5).

[0015] Further, Pd2(dba)3 and P(o-tol)3 are added to react to obtain CP, and the reaction is carried out under reflux conditions, and the reflux time is 20-24h.

[0016] Further, the solution obtained by dissolving CP in THF, wherein the concentration of CP in THF is 1-2 mg / mL;

[0017] The solution obtained by adding DSPE-PEG2000 and Hemin, wherein the concentration of DSPE-PEG2000 in THF is 2-4 mg / mL, and the mass ratio of the added Hemin to DSPE-PEG2000 is 1: (1-2).

[0018] Further, CP was dissolved in THF, and DSPE-PEG2000 and Hemin were added to react to obtain CP@Hemin nanopowder, specifically comprising:

[0019] CP was dissolved in THF, DSPE-PEG2000 and Hemin were added, and deionized water was added after ultrasonic treatment to obtain CP@Hemin dispersion;

[0020] The CP@Hemin dispersion was freeze-dried to obtain CP@Hemin nanopowder;

[0021] Furthermore, the CP is dissolved in THF, DSPE-PEG2000 and Hemin are added, and deionized water is added after ultrasonic treatment, wherein the mass ratio of the added deionized water to THF is (4-10):1.

[0022] Furthermore, the reaction is carried out under an ammonia atmosphere.

[0023] Furthermore, the flexible wood is a flexible wood chip material obtained by chemically removing lignin and hemicellulose from African sycamore, wherein the mass percentage of lignin reduced is 3-6%, and the mass percentage of hemicellulose reduced is 1-2%;

[0024] And / or, the PVA is PVA-1799, with a mass concentration range of 8-15%.

[0025] Furthermore, the treatment temperature of the cyclic freeze-thaw treatment is -25°C~-20°C and 20°C~25°C, and the number of cycles is 3-5 times.

[0026] On the other hand, the present invention provides a photothermal conversion wood-based hydrogel, which is prepared by the preparation method of the wood-based hydrogel provided by the present invention.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The photothermal conversion wood-based hydrogel and the preparation method thereof provided by the present invention are synthesized by a conjugated polymer CP, dissolved in THF, and DSPE-PEG2000 and Hemin are added to obtain CP@Hemin nanopowder. Then, the CP@Hemin nanopowder is compounded with wood and PVA to obtain a photothermal conversion wood-based hydrogel. The wood-based hydrogel has a high photothermal conversion efficiency, can rapidly heat up under the induction of laser in the near-infrared region II, and releases active oxygen free radicals at the same time, and can be applied to photothermal therapy and photodynamic therapy, and has the prospect of being applied to catalysis, medical treatment and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a TEM image of the CP@Hemin nanopowder provided in an embodiment of the present invention;

[0030] Figure 2 This is a photothermal display diagram of the CP@Hemin nanopowder aqueous solution provided in an embodiment of the present invention;

[0031] Figure 3 This is a graph showing the singlet oxygen test results of the CP@Hemin nanopowder provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0033] In the present invention, unless otherwise stated, the experimental methods used in the embodiments of the present invention are conventional methods unless otherwise stated, and the materials, reagents, etc. used are all commercially available unless otherwise stated.

[0034] In the present invention, unless otherwise specified, the alkali-treated flexible wood used is a flexible wood chip material obtained by chemically removing 5% by mass of lignin and 2% by mass of hemicellulose from African sycamore or the like.

[0035] Example 1

[0036] This embodiment provides a photothermal conversion wood-based hydrogel and a preparation method thereof, the method comprising the following steps:

[0037] (1) 0.09 mmol 4,8-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole, 0.08 mmol 4,8-bis[(2-et-hydroxyhexyl)oxy]-2,6-bis(trimethyltinyl)benzo[1,2-b:4,5-b']dithiophene and 0.008 mmol N,N-bis(4-bromophenyl)-N, N-dimethyl-[1,1'-b-phenyl]-4,4'-diamine were added to methanol and stirred vigorously until completely dissolved, and 0.004 mmol Pd2(dba)3 and 0.004 mmol P(o-tol)3 were added and refluxed for 24 h, and then purified to obtain a conjugated polymer CP;

[0038] (2) Dissolve 1 mg CP in 1 mL THF, add 2 mg DSPE-PEG2000 and 1.5 mg Hemin, and quickly add deionized water after sonication to obtain CP@Hemin dispersion. After freeze-drying, CP@Hemin nanopowder was obtained.

[0039] (3) The alkali-treated flexible wood was immersed in a PVA-1799 solution with a mass concentration of 8%, and 10 mg of CP@Hemin nanopowder was added. After mixing evenly, the bubbles were removed under a vacuum environment, and the mixture was freeze-thawed three times at -20°C and 20°C to obtain a photothermal conversion wood-based hydrogel.

[0040] Example 2

[0041] This embodiment provides a photothermal conversion wood-based hydrogel and a preparation method thereof, the method comprising the following steps:

[0042] (1) 0.1 mmol 4,8-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole, 0.06 mmol 4,8-bis[(2-et-hydroxyhexyl)oxy]-2,6-bis(trimethyltinyl)benzo[1,2-b:4,5-b']dithiophene and 0.006 mmol N,N-bis(4-bromophenyl)-N, N-dimethyl-[1,1'-b-phenyl]-4,4'-diamine were added to methanol and stirred vigorously until completely dissolved, and 0.003 mmol Pd2(dba)3 and 0.005 mmol P(o-tol)3 were added and refluxed for 24 h, and then purified to obtain a conjugated polymer CP;

[0043] (2) Dissolve 1.5 mg CP in 2 mL THF, add 4 mg DSPE-PEG2000 and 2.67 mg Hemin, and quickly add deionized water after sonication to obtain CP@Hemin dispersion. After freeze-drying, CP@Hemin nanopowder was obtained.

[0044] (3) The alkali-treated flexible wood was immersed in a 10% mass concentration of PVA-1799 solution, and 8 mg of CP@Hemin nanopowder was added. After mixing evenly, the bubbles were removed under a vacuum environment, and the mixture was freeze-thawed three times at -20°C and 20°C to obtain a photothermal conversion wood-based hydrogel.

[0045] Example 3

[0046] This embodiment provides a photothermal conversion wood-based hydrogel and a preparation method thereof, the method comprising the following steps:

[0047] (1) 0.12 mmol 4,8-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole, 0.1 mmol 4,8-bis[(2-et-hydroxyhexyl)oxy]-2,6-bis(trimethyltinyl)benzo[1,2-b:4,5-b']dithiophene and 0.008 mmol N,N-bis(4-bromophenyl)-N, N-dimethyl-[1,1'-b-phenyl]-4,4'-diamine were added to methanol and stirred vigorously until completely dissolved, and 0.005 mmol Pd2(dba)3 and 0.003 mmol P(o-tol)3 were added and refluxed for 24 h, and then purified to obtain a conjugated polymer CP;

[0048] (2) Dissolve 2 mg CP in 4 mL THF, add 2 mg DSPE-PEG2000 and 2 mg Hemin, and quickly add deionized water after sonication to obtain CP@Hemin dispersion. After freeze-drying, CP@Hemin nanopowder was obtained.

[0049] (3) The alkali-treated flexible wood was immersed in a 12% mass concentration of PVA-1799 solution, and 15 mg of CP@Hemin nanopowder was added. After mixing evenly, the bubbles were removed under a vacuum environment, and the mixture was freeze-thawed three times at -20°C and 20°C to obtain a wood-based hydrogel.

[0050] Figure 1 is a TEM image of the CP@Hemin nanopowder provided in the embodiment of the present invention, such as Figure 1As shown in the figure, the nanopowders obtained by self-assembly of CP, DSPE-PEG2000 and Hemin have a diameter of about 80 nm. Since the conjugated polymer CP will undergo quenching in the dissolved state and has no photothermal effect, it can effectively produce photothermal effect by forming aggregates after self-assembly into spheres.

[0051] The wood-based hydrogel prepared in Example 1 was subjected to a photothermal conversion test. The test method was as follows: 100 ug / mL of CP@Hemin NPs solution was placed in a 1.5 ml centrifuge tube, irradiated with a 1064 nm laser, and photographed using an infrared imager. The test results are shown in Figure 2. Figure 2 As shown, the temperature of the centrifuge tube quickly rises to about 50° C., indicating that the wood-based hydrogel prepared in Example 1 can achieve the purpose of antibacterial by rapid local high temperature inhibition.

[0052] Use DPBF as 1 The photodynamic effect of the wood-based hydrogel prepared in Example 1 was evaluated by using an O2 probe. A mixture of DPBF (concentration of 20 μg / mL) and CP NPs was illuminated by a 1064 nm laser at 0.8 W / cm 2 The photothermal display of CP@hemin nanopowder was obtained by irradiating at low power. Figure 3 The singlet oxygen test results prove that CP can produce photodynamic effect after aggregation, generating ROS that can inhibit bacteria, thereby achieving the purpose of antibacterial.

[0053] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A method for preparing a photothermal conversion wood-based hydrogel, characterized in that: include: 4,8-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole, 4,8-bis[(2-et-hydroxyhexyl)oxy]-2,6-bis(trimethyltinyl)benzo[1,2-b:4,5-b']dithiophene and N,N-bis(4-bromophenyl)-N, N-dimethyl-[1,1'-b-phenyl]-4,4'-diamine were completely dissolved in methanol, and Pd2(dba)3 and P(o-tol)3 were added to react to obtain a conjugated polymer CP; CP was dissolved in tetrahydrofuran, and distearoylphosphatidylethanolamine-polyethylene glycol 2000 was added to react with hemin to obtain CP nanopowder loaded with hemin; The flexible wood was immersed in a polyvinyl alcohol solution, and CP nanopowder loaded with hemin was added and subjected to cyclic freeze-thaw treatment to obtain the wood-based hydrogel.

2. The method for preparing the photothermal conversion wood-based hydrogel according to claim 1, characterized in that: The molar ratios of the added 4,8-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole, 4,8-bis[(2-et-hydroxyhexyl)oxy]-2,6-bis(trimethyltinyl)benzo[1,2-b:4,5-b']dithiophene, N,N-bis(4-bromophenyl)-N, N-dimethyl-[1,1'-b-phenyl]-4,4'-diamine, Pd2(dba)3 and P(o-tol)3 are (8-12):(9-15):(0.6-0.12):(0.3-0.6):(3-5).

3. The method for preparing the photothermal conversion wood-based hydrogel according to claim 1, characterized in that: The Pd2(dba)3 and P(o-tol)3 are added to react to obtain a conjugated polymer, and the reaction is carried out under reflux conditions, and the reflux time is 20-24 hours.

4. The method for preparing the photothermal conversion wood-based hydrogel according to claim 1, characterized in that: The solution obtained by dissolving CP in tetrahydrofuran, wherein the concentration of CP in tetrahydrofuran is 1-2 mg / mL; The solution obtained by adding distearoylphosphatidylethanolamine-polyethylene glycol 2000 and hemin, wherein the concentration of distearoylphosphatidylethanolamine-polyethylene glycol 2000 in tetrahydrofuran is 2-4 mg / mL, and the mass ratio of the added hemin to distearoylphosphatidylethanolamine-polyethylene glycol 2000 is 1:(1-2).

5. The method for preparing the photothermal conversion wood-based hydrogel according to claim 1, characterized in that: CP is dissolved in tetrahydrofuran, and distearoyl phosphatidylethanolamine-polyethylene glycol 2000 is added to react with hemin to obtain CP nanopowder loaded with hemin, specifically comprising: CP was dissolved in tetrahydrofuran, distearoylphosphatidylethanolamine-polyethylene glycol 2000 and hemin were added, and after ultrasonic treatment, deionized water was added to obtain a CP dispersion loaded with hemin; The CP dispersion loaded with hemin is freeze-dried to obtain the CP nanopowder loaded with hemin.

6. The method for preparing the photothermal conversion wood-based hydrogel according to claim 5, characterized in that: The CP is dissolved in tetrahydrofuran, distearoyl phosphatidylethanolamine-polyethylene glycol 2000 and hemin are added, and after ultrasonic treatment, deionized water is added, wherein the mass ratio of the added deionized water to tetrahydrofuran is (4-10):

1.

7. The method for preparing the photothermal conversion wood-based hydrogel according to claim 1, characterized in that: The reaction was carried out under an ammonia atmosphere.

8. The method for preparing the photothermal conversion wood-based hydrogel according to claim 1, characterized in that: The flexible wood is a flexible wood chip material obtained by chemically removing lignin and hemicellulose from African sycamore, wherein the mass percentage of lignin reduced is 3-6%, and the mass percentage of hemicellulose reduced is 1-2%; And / or, the polyvinyl alcohol PVA is PVA-1799, and the mass concentration range is 8-15%.

9. The method for preparing the photothermal conversion wood-based hydrogel according to claim 1, characterized in that: The treatment temperature of the cyclic freeze-thaw treatment is -25°C to -20°C and 20°C to 25°C, and the number of cycles is 3-5 times.

10. A photothermal conversion wood-based hydrogel, characterized in that: The wood-based hydrogel is prepared by the method for preparing the wood-based hydrogel according to any one of claims 1 to 9.

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