Degradable antibacterial fiber and preparation method thereof
Biodegradable antibacterial fibers prepared through gene editing and electrospinning technology solve the problem of dynamic imbalance between long-lasting antibacterial effect and material degradability, achieving a balance between continuous release of antibacterial agents and degradation rate. They possess excellent antibacterial and mechanical properties and are suitable for medical dressings and environmentally friendly packaging.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG RUIWEI NEW MATERIAL TECHNOLOGY CO LTD
- Filing Date
- 2025-08-28
- Publication Date
- 2026-05-19
AI Technical Summary
Existing biodegradable antibacterial fibers face unresolved issues regarding the dynamic imbalance between antibacterial longevity and material degradation, as well as the contradiction between antibacterial agent toxicity and biocompatibility, which limits their large-scale application in medical dressings and environmentally friendly packaging.
Recombinant Escherichia coli was constructed by gene editing, and a gene cluster for the synthesis of phage antimicrobial peptides and polyhydroxy fatty acid esters was integrated. Nanofiber membranes were prepared using electrospinning technology, and a mineralization coating was applied to form a phage antimicrobial peptide-PHBV copolymer, thereby achieving a dynamic balance between the continuous release of antimicrobial agents and the degradation rate.
It achieves a synergistic balance between the long-lasting antibacterial properties, biodegradability, and mechanical properties of antibacterial fibers. After 5 uses, the antibacterial rate exceeds 99%, and the weight loss rate reaches 82% after 90 days. It also has a tensile strength of 18MPa and an elongation at break of 25%, overcoming the inherent defects of traditional methods.
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Figure CN120758998B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of environmentally friendly materials, and in particular relates to a biodegradable antibacterial fiber and its preparation method. Background Technology
[0002] The research and development of biodegradable antimicrobial fibers focuses on solving the dual challenges of medical infection control and plastic pollution control, but it has long faced two core contradictions. The first is the dynamic imbalance between the long-lasting antimicrobial effect and the degradability of materials - traditional physically doped antimicrobial agents are prone to rapid loss, while the degradation rate of biodegradable materials is significantly affected by the environment and is difficult to match with the antimicrobial cycle. The second is the conflict between the toxicity of antimicrobial agents and biocompatibility - metal-based antimicrobial agents such as silver ions have the risk of cytotoxicity and ecological accumulation, while natural antimicrobial peptides face the problems of poor stability and easy loss of activity. These contradictions directly restrict their large-scale application in medical dressings, environmentally friendly packaging and other scenarios.
[0003] While existing solutions offer breakthroughs, they also have significant limitations. Gene editing technology enhances long-lasting efficacy by synergistically expressing antimicrobial peptides and PHBV, but is constrained by the fermentation stability of engineered bacteria. Nanocarrier sustained-release systems can optimize release curves, but their high cost and insufficient compatibility hinder widespread adoption. Biomimetic mineralization coatings can delay degradation, but suffer from low production efficiency. Traditional strategies often focus on optimizing a single dimension, failing to systematically balance the triangular relationship between antimicrobial activity, degradation, and safety, resulting in compromised performance in practical applications.
[0004] Future breakthroughs will require interdisciplinary innovation, integrating technologies such as gene editing, nanocarriers, and biomimetic mineralization to construct an integrated antibacterial-degradation-repair system. The pathway described above, where phage antimicrobial peptide-PHBV synergistic expression combines with a mineralized coating, achieves sustained antimicrobial agent release through gene regulation while balancing the degradation rate through the mineralized layer, providing a new paradigm for resolving the core challenge. With technological maturity and cost reduction, these fibers are expected to achieve breakthroughs in fields such as medical implants and environmentally friendly packaging, driving the industry from functional superposition to systemic synergy. Summary of the Invention
[0005] To address the challenges of achieving a dynamic balance between the long-lasting properties of antibacterial fibers and the degradability of materials, as well as the contradiction between the toxicity of antibacterial agents and their biocompatibility.
[0006] To address the above problems, the present invention provides the following technical solution:
[0007] A biodegradable antibacterial fiber and its preparation method, comprising the following components:
[0008] 8-10 parts of phage antimicrobial peptide, 65-70 parts of polyhydroxy fatty acid ester, 1-2 parts of sodium hypochlorite, 2-5 parts of 1-ethyl-3-methylimidazolium acetate, 0.5-1 part of boric acid, and 3-6 parts of CaCl2 / Na2HPO4 / sodium alginate mineralization solution.
[0009] Preferably, the phage antimicrobial peptide is a gene cloned from the genome of phage φ87S / 06, and the encoded antimicrobial peptide is a natural antimicrobial polypeptide derived from phage.
[0010] Preferably, the main component of the polyhydroxy fatty acid ester is poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and its main chain is a linear polyester.
[0011] Preferably, the ratio of CaCl2 / Na2HPO4 / sodium alginate mineralization solution is 3:2:2.
[0012] A method for preparing a biodegradable antibacterial fiber includes the following steps:
[0013] S1: Recombinant Escherichia coli was constructed using gene editing technology, integrating the antimicrobial peptide gene derived from bacteriophage with the polyhydroxyalkanoate synthesis gene cluster, knocking out the PHA synthesis repressor gene phaR and overexpressing the phaCAB operon, and inserting an IPTG inducible promoter before the antimicrobial peptide gene to achieve synergistic expression of the antimicrobial peptide and PHBV, thus obtaining a dual-plasmid engineered bacterium.
[0014] S2: Feed-and-dose fermentation was carried out in an optimized glucose-propionic acid medium to induce the synthesis of PHBV in the cells. The antimicrobial peptide-PHBV copolymer was then separated by dissolving the cells with sodium hypochlorite, ultrasonic disruption, and ethanol precipitation.
[0015] S3: Dissolve the antimicrobial peptide-PHBV copolymer in the ionic liquid 1-ethyl-3-methylimidazolium acetate, then add boric acid as a dynamic crosslinking agent, and then sonicate to form a homogeneous solution;
[0016] S4: Nanofiber membranes were prepared using electrospinning technology, and the average fiber diameter was controlled. The membranes were then heat-treated at 60°C for 2 hours.
[0017] S5: Immerse the fiber membrane in CaCl2 / Na2HPO4 / sodium alginate mineralization solution, and then shake for 24 hours to form a hydroxyapatite / alginate composite coating.
[0018] Preferably, in S2, the induced bacterial cell count reaches 35 g / L and the PHBV percentage accounts for 68% of the cells.
[0019] Preferably, in S3, the concentration of the antimicrobial peptide-PHBV copolymer in the solution is 8 wt%, and the amount of boric acid added is 0.5 wt%.
[0020] Preferably, the electrospinning technology used in S4 has a voltage of 18kV, a receiving distance of 15cm, and an average fiber diameter of 200-300nm.
[0021] Preferably, in step S4, the fiber membrane obtained by electrospinning is heat-treated at 60°C for 2 hours.
[0022] Preferably, S5 is immersed in a liquid at 37°C and shaken for 24 hours.
[0023] The effects and advantages of the biodegradable antibacterial fiber and its preparation method of the present invention are as follows:
[0024] 1. This invention constructs a dual-plasmid engineered bacterium through gene editing, integrates the gene clusters for phage antimicrobial peptides and polyhydroxy fatty acid ester synthesis, knocks out the PHA synthesis repressor gene phaR and overexpresses the phaCAB operon, and simultaneously inserts an IPTG inducible promoter to achieve synergistic expression of the two.
[0025] 2. This invention uses an optimized glucose-propionic acid medium for fed-batch fermentation, achieving a cell concentration of 35 g / L and a PHBV content of 68% after induction, resulting in high fermentation efficiency. The separation process involves dissolving cells with sodium hypochlorite, ultrasonic disruption, and ethanol precipitation, which can efficiently purify the antimicrobial peptide-PHBV copolymer, thereby ensuring the purity and activity of the product.
[0026] 3. In this invention, the ionic liquid 1-ethyl-3-methylimidazolium acetate is used to dissolve the copolymer, avoiding pollution from traditional organic solvents. Boric acid is added as a dynamic crosslinking agent, and the mechanical stability and degradability of the material are balanced through reversible dissociation / binding characteristics, thus solving the problem of the difficulty in achieving both rigidity and toughness.
[0027] 4. In this invention, electrospinning technology precisely controls the average diameter of fibers. The porous structure of the nanofiber membrane is conducive to the release of antibacterial components and contact with the degradation medium. Heat treatment at 60℃ further stabilizes the structure. The mineralization step forms a hydroxyapatite / alginate composite coating through the CaCl2 / Na2HPO4 / sodium alginate system, which not only significantly improves the antibacterial performance but also regulates the degradation rate, achieving synchronization of the antibacterial cycle and the degradation cycle.
[0028] 5. The present invention achieves a final product that simultaneously achieves long-lasting antibacterial effect, excellent biodegradability and balanced mechanical properties, overcoming the inherent defects of traditional methods and achieving a synergistic balance between antibacterial, degradation and mechanical properties. Attached Figure Description
[0029] Figure 1 This is a flowchart illustrating the preparation process of a biodegradable antibacterial fiber according to the present invention. Detailed Implementation
[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0032] Example 1
[0033] This embodiment provides a method for preparing biodegradable antimicrobial fibers, using recombinant Escherichia coli as the production strain to prepare biodegradable antimicrobial fibers. The specific implementation details are as follows:
[0034] Experimental objective:
[0035] Preparation of biodegradable antibacterial fibers
[0036] Experimental materials:
[0037] Phage antimicrobial peptides, polyhydroxy fatty acid esters, glucose-propionic acid medium, sodium hypochlorite, 1-ethyl-3-methylimidazolium acetate, boric acid, CaCl2 / Na2HPO4 / sodium alginate mineralization solution.
[0038] Experimental steps:
[0039] S1: Recombinant Escherichia coli was constructed using gene editing technology, integrating the antimicrobial peptide gene derived from bacteriophage with the polyhydroxyalkanoate (PHA) synthesis gene cluster, knocking out the PHA synthesis repressor gene phaR and overexpressing the phaCAB operon, and inserting an IPTG inducible promoter before the antimicrobial peptide gene to achieve synergistic expression of the antimicrobial peptide and PHBV, thus obtaining a dual-plasmid engineered bacterium.
[0040] S2: Feed-and-dose fermentation was carried out in an optimized glucose-propionic acid medium. After induction, the cell count reached 35 g / L and the PHBV content in the cells was 68%. The antimicrobial peptide-PHBV copolymer was then separated by dissolving the cells with sodium hypochlorite, ultrasonic disruption, and ethanol precipitation.
[0041] S3: Dissolve the antimicrobial peptide-PHBV copolymer in the ionic liquid 1-ethyl-3-methylimidazolium acetate to prepare a solution with a concentration of 8wt%, then add 0.5wt% boric acid as a dynamic crosslinking agent, and then sonicate to form a homogeneous solution.
[0042] S4: Nanofiber membranes with an average fiber diameter of 200-300 nm were prepared by electrospinning technology with an 18 kV voltage and a receiving distance of 15 cm, and then heat-treated at 60 °C for 2 hours.
[0043] S5: The fiber membrane is immersed in CaCl2 / Na2HPO4 / sodium alginate mineralization solution, and then shaken at 37°C for 24 hours to form a hydroxyapatite / alginate composite coating.
[0044] Experimental results: See Table 1 for details.
[0045] Table 1: Test Results of Example 1
[0046]
[0047] Example 1 describes the successful preparation of a biodegradable antimicrobial fiber by constructing recombinant Escherichia coli to achieve the synergistic expression of phage antimicrobial peptides and polyhydroxy fatty acid esters. The fiber was then processed through fermentation separation, ionic liquid dissolution and cross-linking, electrospinning, and mineralization. Test results showed that the fiber exhibited an antimicrobial rate exceeding 99% after five cycles and a weight loss of 82% after 90 days. It also possessed a tensile strength of 18 MPa and an elongation at break of 25%. This not only verified the feasibility of the preparation method in the claims of this invention but also demonstrated excellent long-lasting antimicrobial activity, biodegradability, and mechanical properties, achieving an effective balance between antimicrobial function and material degradability.
[0048] Comparative Example 1
[0049] This embodiment provides a method for preparing an antibacterial agent-degradable polymer melt blend spinning, as detailed below:
[0050] Experimental objective:
[0051] Antibacterial fibers were prepared using melt blending spinning.
[0052] Experimental materials:
[0053] Natural antibacterial agents (such as chitosan and plant essential oils), biodegradable polymers (polylactic acid PLA, polybutylene succinate PBS), solubilizers (maleic anhydride PLA), and lubricants (magnesium stearate).
[0054] Experimental steps:
[0055] S1: Mix chitosan powder and PLA particles at a ratio of 5-10%, add compatibilizer, and feed the mixture into a twin-screw extruder. Melt blend at 170-190℃ to fully disperse the antibacterial agent in the PLA matrix and prepare antibacterial masterbatch.
[0056] S2: The masterbatch is passed through a melt spinning machine, with the spinning temperature set to 160-180℃ and the draw ratio to 3-5. After spinning into fibers, antibacterial fibers are obtained after heat setting.
[0057] Experimental results: See Table 2 for details.
[0058] Table 2: Test Results of Comparative Example 1
[0059]
[0060] Compared to Example 1, the results demonstrate a typical defect of the melt blending spinning method—poor compatibility between the antibacterial agent and the PLA matrix, leading to a sharp drop in the antibacterial rate to 45% after 5 uses, and rapid precipitation of the antibacterial agent. The 55% weight loss after 90 days indicates a mismatch between the fiber degradation rate and the antibacterial cycle. While the tensile strength of 49 MPa is higher than in Example 1, the elongation at break is only 2.5%, showing significant brittleness and poor mechanical property uniformity, a stark contrast to the high toughness of Example 1.
[0061] Comparative Example 2
[0062] A method for preparing biodegradable antibacterial fibers using a surface coating method is provided, the implementation details of which are as follows:
[0063] Experimental materials:
[0064] Polyhydroxyalkanoate fiber (PHBV), silver nanoparticles (antibacterial agent), polyvinyl alcohol (PVA), ethanol.
[0065] Experimental objective:
[0066] Biodegradable antibacterial fibers were prepared using a surface coating method.
[0067] Experimental steps:
[0068] S1: When preparing PHBV fibers by melt spinning, the spinning temperature is set to 140-150℃, and the fibers are dried after being washed with water to remove surface impurities.
[0069] S2: Prepare an ethanol solution containing 0.5-1% silver nanoparticles and 5% PVA, immerse the PHBV fiber in the solution for 30 minutes, remove it and dry it in an oven at 60℃ to allow the PVA-silver nanoparticle coating to adhere to the fiber surface.
[0070] Experimental results: See Table 3 for details.
[0071] Table 3: Test Results of Comparative Example 2
[0072]
[0073] The results in Comparative Example 2 reflect a typical defect of the surface coating method – due to the weak bonding between the PVA-silver nanoparticle coating and the PHBV fiber, the antibacterial rate was only 35% after 5 uses, indicating significantly insufficient long-term antibacterial effect. The coating hinders fiber contact with the environment, resulting in a weight loss of only 53% after 90 days, thus inhibiting degradation performance. The tensile strength of 15 MPa is slightly lower than in Example 1, and the elongation at break of 12% is also lower than 25% of Example 1, indicating that the brittle characteristics of the coating affect the overall toughness of the fiber, resulting in poor balance of mechanical properties. This further highlights the limitations of the surface coating method in terms of antibacterial durability, degradation compatibility, and mechanical coordination.
[0074] refer to Figure 1 The preparation process is illustrated in Example 1. A dual-plasmid engineered bacterium was constructed using gene editing. By integrating antimicrobial peptides and polyhydroxyalkanoates (PHBV) synthesis gene clusters, an antimicrobial peptide-PHBV copolymer was obtained through batch fed-batch fermentation, separation, and purification. This copolymer was then dissolved in ionic liquids, cross-linked with boric acid, electrospinned, and treated with a mineral coating to successfully prepare a biodegradable antimicrobial fiber. Test results showed that the fiber achieved an antimicrobial rate exceeding 99% after five cycles, a weight loss of 82% after 90 days, and a tensile strength of 18 MPa and an elongation at break of 25%, achieving an effective balance between long-lasting antimicrobial activity, biodegradability, and mechanical properties.
[0075] Comparative Example 1 employed an antibacterial agent-biodegradable polymer melt blending and spinning method, where chitosan and PLA were melt-blended and then spun. The results showed that the antibacterial rate after 5 cycles was only 45%, the weight loss after 90 days was 55%, and although the tensile strength reached 49 MPa, the elongation at break was only 2.5%. This method suffers from drawbacks such as poor compatibility between the antibacterial agent and the matrix, easy precipitation of the antibacterial agent, mismatch between the degradation rate and the antibacterial cycle, and significant material brittleness, resulting in poor uniformity of mechanical properties.
[0076] Comparative Example 2 used a surface coating method to coat the surface of PHBV fibers with a PVA coating containing silver nanoparticles. The test results showed an antibacterial rate of 35% after 5 cycles, a weight loss rate of 53% after 90 days, a tensile strength of 15 MPa, and an elongation at break of 12%. Its drawbacks include weak adhesion between the coating and the fiber, resulting in insufficient long-term antibacterial effect; the coating hinders degradation, leading to a low weight loss rate; and the brittleness of the coating affects the overall toughness of the fiber, resulting in poor balance of mechanical properties.
[0077] As can be seen from the comparison, Example 1 demonstrates a comprehensive advantage over Comparative Examples 1 and 2 in key performance aspects, which is directly related to its innovative technological approach. Regarding long-lasting antibacterial activity, Example 1 maintained an antibacterial rate of >99% after 5 uses, significantly higher than Comparative Example 1's 45% and Comparative Example 2's 35%. This is attributed to its molecular-level composite of antimicrobial peptides and PHBV achieved through gene editing, avoiding the rapid precipitation caused by poor compatibility between the antimicrobial agent and the matrix in Comparative Example 1, and the loss of antimicrobial components caused by coating peeling in Comparative Example 2, thus ensuring the long-lasting stability of the antimicrobial function. In terms of biodegradability, Example 1 achieved a weight loss rate of 82% after 90 days, significantly higher than Comparative Example 1's 55% and Comparative Example 2's 53%. Because its integrated structure is not hindered by physical mixing or surface coatings, it can more fully contact the environment and degrade, meeting the core requirements of environmentally friendly materials. In terms of mechanical properties, the 18 MPa tensile strength and 25% elongation at break of Example 1 form a better balance, which not only overcomes the high brittleness caused by the agglomeration of antibacterial agent in Comparative Example 1, but also improves the insufficient toughness caused by the poor bonding between the coating and the substrate in Comparative Example 2, fully demonstrating its significant technical advantages in antibacterial durability, degradation compatibility and mechanical coordination.
[0078] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0079] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, with two or more modules integrated into one module.
[0080] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.
[0081] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included in the protection of the present invention.
Claims
1. A method for preparing a biodegradable antibacterial fiber, characterized in that, Includes the following steps: S1: Recombinant Escherichia coli was constructed using gene editing technology. 8-10 parts by weight of the antimicrobial peptide gene derived from bacteriophage were integrated with 65-70 parts by weight of the polyhydroxyalkanoate synthesis gene cluster. The PHA synthesis repressor gene phaR was knocked out and the phaCAB operon was overexpressed. At the same time, an IPTG inducible promoter was inserted before the antimicrobial peptide gene to achieve the synergistic expression of the antimicrobial peptide and PHBV, thus obtaining a dual-plasmid engineered bacterium. S2: Feed-and-dose fermentation was carried out in an optimized glucose-propionic acid medium to induce the synthesis of PHBV in the cells. The antimicrobial peptide-PHBV copolymer was then separated by dissolving the cells with 1-2 parts by weight of sodium hypochlorite, ultrasonically disrupting and precipitating with ethanol. S3: Dissolve the antimicrobial peptide-PHBV copolymer in 2-5 parts by weight of ionic liquid 1-ethyl-3-methylimidazolium acetate, then add 0.5-1 parts by weight of boric acid as a dynamic crosslinking agent, and then sonicate to form a homogeneous solution; S4: Nanofiber membranes were prepared using electrospinning technology, and the average fiber diameter was controlled. The membranes were then heat-treated at 60°C for 2 hours. S5: Immerse the fiber membrane in 3-6 parts by weight of CaCl2 / Na2HPO4 / sodium alginate mineralization solution, and then shake for 24 hours to form a hydroxyapatite / alginate composite coating. The antimicrobial peptide gene derived from bacteriophage in S1 comes from the genome of bacteriophage φ87S / 06, and the antimicrobial peptide encoded by the genome of bacteriophage φ87S / 06 belongs to the natural antimicrobial polypeptide derived from bacteriophage.
2. The method for preparing a biodegradable antibacterial fiber as described in claim 1, characterized in that, The polyhydroxy fatty acid ester mentioned in S1 is poly(3-hydroxybutyrate-co-3-hydroxyvalerate), whose main chain is a linear polyester.
3. The method for preparing a biodegradable antibacterial fiber as described in claim 1, characterized in that, In the S2, the induced bacterial cell count reached 35 g / L, and the PHBV content in the cells was 68%.
4. The method for preparing a biodegradable antibacterial fiber as described in claim 1, characterized in that, In S3, the concentration of the antimicrobial peptide-PHBV copolymer in the solution is 8 wt%, and the amount of boric acid added is 0.5 wt%.
5. The method for preparing a biodegradable antibacterial fiber as described in claim 1, characterized in that, The electrospinning technology used in S4 has a voltage of 18kV, a receiving distance of 15cm, and an average fiber diameter of 200-300nm.
6. The method for preparing a biodegradable antibacterial fiber as described in claim 1, characterized in that, In step S4, the fiber membrane obtained by electrospinning is heat-treated at 60°C for 2 hours.
7. The method for preparing a biodegradable antibacterial fiber as described in claim 1, characterized in that, The S5 is immersed in a liquid at 37°C and shaken for 24 hours.
8. The method for preparing a biodegradable antibacterial fiber as described in claim 1, characterized in that, The ratio of CaCl2 / Na2HPO4 / sodium alginate mineralization solution described in S5 is 3:2:2.