CZ2014920A3 - Process for preparing polymeric fibers with diameter in the range of 100 nm to 10 microns and process for preparing linear, flat or spatial formation comprising such polymeric fibers - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing polymer fibers having a diameter of 100 nm to 10 .mu.m in which a drop (2) of a solution or melt of polymer of at least 0.001 .mu.m volume is formed on the surface of the substrate (1) during or after the end of at least one elongated spinning element (3) is immersed therein, on which surface and / or in the cavity a portion of the polymer solution or melt is trapped from the droplet (2), whereupon the spinning element (3) is bent by the manipulator, and / or by moving the substrate (1) to another location of the same or another substrate (1). The solution or melt of the polymer on its surface and / or in its cavity, due to its viscosity and surface tension, remains during this movement interconnected by a solution or melt fiber (4) of polymer whose diameter decreases when the spinning element (3) and / or substrate (1) moves , and the fiber (4) anchors upon subsequent contact of the spinning element end (3) with the surface of the substrate (2), whereby a polymeric fiber having a diameter of 100 nm to 10 µm is deposited on the surface of the substrate (2). The invention further relates to a method for producing a linear, planar or spatial structure with polymer fibers having a diameter of 100 nm to 10 µm, which is formed in this way and stored in the desired direction and orientation in space or area.

Description

Process for the production of polymeric fibers with a diameter of 100 nm to 10 μm, and process for the production of a linear, planar or spatial structure containing these polymeric fibers

Field of technology

The invention relates to a process for the production of polymer fibers with a diameter of 100 nm to 10 [mu] m.

The invention furthermore relates to a process for the production of linear, planar and three-dimensional structures comprising polymeric fibers with a diameter of 100 nm to 10 [mu] m.

Prior art

A typical product of all known methods for the production of polymeric nanofibers, ie fibers with a diameter of about 100 to 1000 nm by electrostatic spinning of polymer solutions or melts using static needle spinning electrodes (nozzles, capillaries, etc.) or moving level spinning electrodes (rotating roller - see eg CZ 299549, a string moving in the direction of its length or in a circular path - see eg CZ 299549 and CZ 300345, rotating spiral, disk, etc.), or by centrifugal spinning, where the polymer solution or melt is extruded / extruded by centrifugal force from the holes formed in the housing of the rotating body in the shape of a disc (see e.g. DE 102005048939) or a cylinder (see e.g. JP 2008127726), a flat layer of randomly deposited and intertwined polymeric nanofibers is formed. Although it has a number of uses in combination with other support or cover layers, especially in the field of filtration and hygiene products, it is of limited use for many other areas and applications, such as tissue engineering, regenerative medicine, etc. These applications in principle require rather separate planar or spatial nanofiber formations with a specific internal structure and with polymeric nanofibers, or even fibers of larger diameters, oriented in the desired direction (s), determining the desired direction / directions of cell growth, resp. cell colonization of this formation.

PS3996CZ

Although several methods based on the use of an air / gas stream have been proposed for the orientation of polymeric nanofibers during their production and possibly during their deposition on a substrate (see e.g. US 6308509 for depositing polymeric nanofibers on a fibrous core in a suction tube, or US 2005008776 for polymerizing nanofibers by air flow immediately after their formation), or alternating electric voltage (see e.g. US 2004013819, or analogous EP patent 1335999, or WO 2008106381 using a specifically shaped collector on which polymeric nanofibers are deposited, or US 2004061253 using auxiliary ring electrodes used to narrow and direct the current of polymer nanofibers emanating from the spinning electrode formed by the nozzle), none of them is applicable in practice, because as shown in practical testing, the orientation of polymer nanofibers occurs only to a limited extent and the internal structure of formed structures is still rather random and disorganized.

The object of the invention is to propose a method for the production of polymeric nanofibers, possibly also polymeric microfibres with a diameter of up to 10 .mu.m, which would allow the greatest possible degree of orientation (isotropy) of individual fibers, and the formation of linear, planar and spatial formations containing these polymeric fibers with the desired orientation location.

The essence of the invention

The object of the invention is achieved by a process for the production of polymer fibers with a diameter of 100 nm to 10 [mu] m, which comprises forming a drop of polymer solution or melt with a volume of at least 0.001 [mu] l on the surface of the substrate, immersing the end of at least one elongate spinning element. In doing so, a part of the polymer solution or melt is trapped on its surface and / or in its cavity, after which the spinning element is moved to another location of the same or another substrate by moving the manipulator on which it is placed and / or by moving the substrate, the polymer solution or melt on its surface and / or in its cavity, during this movement, due to its viscosity and surface tension, it remains connected by a fiber, the diameter of which decreases with the movement of the spinning element and / or the substrate, with a drop of solution or melt on the surface.

PS3996CZ substrate. Upon subsequent contact of the end of the spinning element with the surface of the substrate, this fiber is anchored. In this way, a polymer fiber with a diameter of 100 nm to 10 μm with the desired length and orientation is formed and deposited on the surface.

A drop of polymer solution or melt can be formed on the surface of the substrate, for example by applying the polymer solution or melt by means of an applicator or manually, applying the polymer solution or melt to the surface and / or cavity of the spinning element, or forcing the polymer solution or melt from the solution reservoir or polymer melts through the cavity of the hollow spinning element. In a preferred embodiment variant, the hollow spinning element is mounted on the cartridge and its cavity is connected to the interior of this cartridge with the stored polymer solution or melt.

A suitable hollow spinning element is a hollow conical needle whose outlet opening has a diameter of 0.1 to 1.2 mm, or a tube with an outer diameter of 0.1 to 1.5 mm. However, a rod of this diameter can also be used.

In a preferred variant of carrying out the method according to the invention, the substrate remains static and only the spinning element moves, preferably along an arcuate trajectory, reaching a maximum speed of 1 to 100 m / min. However, if necessary, its speed can be higher.

When spinning some polymers, e.g., polycaprolactone, etc., it is advantageous if the movement of the spinning element is stopped before contact with the substrate surface, and continues after at least partial solidification of the fiber. This results in a smaller diameter of the fiber to be formed, since no more material from the starting drop is fed into it.

An end drop of polymer solution or melt is preferably used to anchor the end of the fiber to the surface of the substrate, as in this case its anchoring is more secure, and the end drop material may additionally be used to form additional fibers. The end drop can be deposited on the same or different substrate than the starting drop of the polymer solution or melt.

PS3996CZ

When using a hollow spinning element, the end drop is preferably formed by forcing at least 0.001 μΙ of polymer solution or melt from the interior of the spinning element.

In order to form a suitable material structure of the fiber, it is advantageous if the fiber formed is stimulated by an electric current, whereby a high direct voltage of any polarity is applied to the spinning element and to the electrically conductive substrate. At the same time, the conformation of the polymer macromelucules is influenced, and the fiber formed thus achieves significantly better geometric and mechanical properties.

Polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polystyrene (PS), poly (methyl methacrylate) (PMMA), polycaprolactone (PCL), polyurethane (PU) are particularly suitable polymers for forming fibers with a diameter of 100 nm to 10 .mu.m. , a modified variant of any of them, or any mixture or copolymer of at least two of them.

The object of the invention is furthermore also achieved by a process for the production of a linear or planar structure comprising polymer fibers with a diameter of 100 nm to 10 [mu] m, the essence of which consists in that polymer fibers with a diameter of 100 nm to 10 [mu] m formed by the process according to the invention they are placed side by side and / or on top of each other in the desired mutual orientation, thus forming a linear shape or a planar shape.

In addition, the object of the invention is also achieved by a method for producing a sheet or three-dimensional structure comprising polymer fibers with a diameter of 100 nm to 10 μm, in which polymer fibers with a diameter of 100 nm to 10 μm formed by the method according to the process are repeatedly deposited in parallel and / or differently. in the same way, it forms polymer fibers with a diameter of 100 nm to 10 [mu] m from the same or different material, which are deposited on them with the same or different orientation.

For possible further processing of the structures thus formed or their removal from the substrate, it is advantageous if the individual polymer fibers are anchored at their ends on a substrate other than the one on which the initial drop of polymer solution or melt from which these fibers are formed is deposited.

PS3996CZ

In the production of a three-dimensional structure, it is possible to deposit polymeric fibers with a diameter of 100 nm to 10 [mu] m on a three-dimensionally shaped substrate, these fibers and the structure formed by them at least partially copying its shape.

Explanation of drawings

In the accompanying drawings, Fig. 1 schematically shows the principle of a method for producing polymer fibers with a diameter of 100 nm to 10 μm according to the invention, Fig. 2 shows the principle of another variant of this method, Fig. 3 shows an SEM image of a linear structure containing polymer nanofibers formed by the method according to the invention. magnification 480x, in Fig. 4 SEM image of this linear structure at 1000x magnification, in Fig. 5 SEM image of this linear structure at 3000x magnification, in Fig. 6 SEM image of this linear structure at 5000x magnification, in Fig. 7 SEM image of linear structure containing polymer nanofibers formed by the method according to the invention with an additional twist at a magnification of 500x, in Fig. 8 an SEM image of a sheet comprising parallel polymer nanofibers formed by the method according to the invention at 500x magnification, in Fig. 9 an SEM image of a sheet containing a grid of nanofibers formed by the method according to the invention at a magnification of 500x, in Fig. 10 an SEM area image of a structure comprising a lattice of intersecting polymeric nanofibers formed by the method according to the invention seeded with living cells at 25x magnification, Fig. 11 Fig. 13 is a fluorescence microscope image of a cross-section of a cross-section of intersecting polymeric nanofibers formed by the method of the invention, planted with living cells at 200x magnification; Fig. 13 is an SEM image of a cross-section of a cross-section of a cross-section of nanofibers. two polymers formed by the process of the invention.

PS3996CZ

Examples of embodiments of the invention

The process for the production of polymer fibers with a diameter of 100 nm to 10 [mu] m according to the invention is based on the use of the viscosity of the solution or melt of the polymer and its resp. its intermolecular forces to "pull" the individual fibers out of the drop (s) of polymer solution or melt deposited on the adhesive backing. The principle of this method will be further explained with reference to Fig. 1 and Fig. 2. In this method, a drop 2 of a polymer solution or melt, with a volume of preferably 0.001 to 4.2 .mu.l, possibly even larger, is first formed on the surface of the adhesive substrate 1. into which, during or after its formation, an elongate spinning element (in the shape of a (conical) needle, tube or rod is immersed at one end, the end of which is formed by a flat surface, a tip, a bevel or a rounding, etc.). the part which is immersed in a drop 2 of polymer solution or melt is generally 0.1 to 1.5 mm.

This spinning element 3 is preferably mounted on a manipulator (not shown) which is able to move in at least two axes - vertically perpendicular to the substrate 1 (arrow y) and horizontally along the length of one of the dimensions of the substrate 1, (arrow z) and preferably horizontally along the length of the second of its dimensions (arrow x), or arbitrarily oblique. However, any of these movements of the manipulator can be replaced or supplemented by a corresponding movement of the substrate 1. In addition, it is further advantageous for the manipulator, or a part thereof with the spinneret 3 mounted, to rotate around at least one to form more complex, e.g. one axis.

By moving this manipulator, the spinning element 3 is then pulled out of the drop 2 of polymer solution or melt and along the trajectory T, which has the preferred arcuate shape in Fig. 1, but can generally have any other shape (and e.g. when the substrate 1 is suitably shaped, or when the spinning element 3 moves between two substrates suitably arranged in space 1, the trajectory can be rectilinear), moves in the desired direction and at a selected, even variable, speed to the desired distance from the polymer solution or melt drop 2, where again When the spinning element 3 is immersed in the drop 2, a small amount of polymer solution or melt adheres to its surface and / or its cavity, which remains

Due to the viscosity and surface tension of this material, it is connected to the starting droplet 2 by a thin fiber 4 of this material throughout the movement of the spinning element 3, and whose naturally small diameter decreases even further with its length (or with the path length of the spinning element 3). In this way, a separate polymeric fiber of the desired diameter, length and orientation is gradually formed. Upon subsequent contact of the spinning element 3 with the surface of the substrate 1, this fiber 4 is terminated and anchored at its other end to the surface of the substrate 1 (with its first end it is anchored in the initial drop 2). Due to the large surface area and the intense evaporation of the solvent (caused in particular by the increasing capillary pressure inside the drawn fiber), it solidifies relatively quickly, it being advantageous if it solidifies completely just at or quickly after anchoring its other end. On the other hand, when spinning some polymers, e.g. polycaprolactone, it is advantageous if the movement of the spinning element 3 along the trajectory T stops for a certain moment (units up to tens of seconds) and continues only after the formed fiber 4 partially solidifies. its smaller diameter is then reached, since no further material from the starting drop 2 is fed into it.

After the polymer fiber has been formed and anchored to the surface of the substrate 1, the spinning element 3 is returned to the initial drop 2 of polymer solution or melt to absorb material to draw further fiber 4 by immersion therein. This process is then repeated in the same manner until creating the required number of fibers or the desired linear, planar or spatial structure. In this case, it is advantageous if an end drop 20 of polymer solution or melt is formed at the anchoring point of the other end of the formed fibers 4 on the surface of the substrate 7, so that individual fibers 4 are formed or can be formed during the reversible phase of the spinning element 3. of the substrate 1 to form substantially any number of starting and / or end droplets 2, 20 of polymer solution or melt, and by one or more identical or different spinning elements 3 to form substantially any surface structure of fibers with a diameter of 100 nm to 10 μm of one or more polymers. Each drop 2, 20 can simultaneously serve as an end, i.e. to anchor the end of the fiber 4

PS3996EN created in the previous step, and at the same time as a source of material for the subsequently formed fiber 4, and vice versa.

After processing a predetermined amount of polymer solution or melt from the starting drop 2 and / or the end drop 20, or after the starting drop 2 and / or the end drop 20 has solidified, a new starting drop 2 or new end drop is formed on the surface of the substrate 1 in the same way. 20. This drop (s) 2, 20 can be formed on the surface of the substrate 1, for example by a dosing device (not shown) with forced or spontaneous movement of the polymer solution or melt, manually or by applying the required amount of polymer solution or melt to the surface of the substrate 1. a spinning element 3, which is previously immersed in a solution or melt of polymer deposited in a container (not shown) on or outside the substrate 1.

In a variant of the method for producing polymer fibers according to the invention shown in Fig. 2, the polymer solution or melt is deposited in the interior of the cartridge 5, which is divided by a piston 6 or a membrane into two parts, one of which is connected to the cavity of the hollow elongate spinning element 3. , which in this variant is preferably a hollow conical needle (i.e. capillary) 30, but any other hollow spinning element 3 can be used, and the other is connected to a source of pressure medium (gas, preferably air or liquid), or is a piston 6 or the diaphragm in a variant (not shown) is coupled / coupled to a mechanical drive. Due to the inertial action, it is advantageous in the first variant if the source of pressure medium is mounted on a stationary part of the polymer fiber-forming device. The cartridge 5 is mounted on a manipulator (not shown) which is able to move in at least two axes - vertically perpendicular to the substrate 1 (arrow y) and horizontally along the length of one of the dimensions of the substrate 1 (arrow z) and preferably horizontally along the length of the other of its dimensions ( arrow x), or arbitrarily oblique. However, any of these manipulator movements can be replaced or supplemented by a corresponding movement of the substrate L. In addition, it is further advantageous for the manipulator, or a part thereof with the spinneret 3 mounted, to rotate around at least one to create more complex, e.g. axis.

PS3996CZ

The hollow conical needle 30 is preferably made of an electrically conductive material (but can also be made of an electrically non-conductive material) and its outlet opening has a diameter of 0.1 to 1.2 mm.

In this method of manufacturing polymer fibers, the tip of the hollow conical needle 30 approaches or comes into contact with the surface of the substrate 1 by moving the manipulator, followed by an impulse of a pressure medium (e.g. gas or liquid) on the opposite side of the piston 6 or cartridge membrane 5. of a mechanical drive (not shown) (see arrow P) pushes the required amount of polymer solution or melt (preferably 0.001 to 4.2 μΙ, or more) through the cavity of the conical needle 30, thereby forming a drop 2 of this material on the surface of the substrate e. After its formation, the hollow conical needle 30 is moved by means of a manipulator along a trajectory T, which in FIG. 2 has the preferred arcuate shape, but can generally have any other shape, in the desired direction to the desired distance from the polymer drop or melt. brings it back into contact with the substrate £. In this way, a separate polymeric fiber 4 of the desired diameter, length and orientation is formed in the manner described above. This is terminated and anchored by the subsequent contact of the hollow conical needle 30 with the surface of the substrate 6. Then, the hollow conical needle 30 is returned by means of a manipulator to the initial drop 2 of polymer solution or melt to pick up material on its tip for drawing another fiber 4 by contact with or immersing it, which is repeated until the desired number of fibers or the desired linear , planar or spatial unit.

Also in this variant, in order to achieve smaller diameters of the formed fibers 4, the above-described extension can be used, in which the movement of the hollow conical needle 30 along the trajectory T is stopped for a certain moment (units up to tens of seconds), while the formed fiber 4 partially solidifies.

In another embodiment, not shown, the movement of the piston 6 or the diaphragm in the cartridge 5 can be replaced by the use of capillary forces, in which an elongate guide element (e.g. (nano) tungsten wire) is longitudinally mounted in the cavity of the conical needle 30. of its radius, and which forms a conduit of the polymer solution or melt, naturally dividing the polymer solution or melt into droplets, even with a smaller volume and with greater accuracy than the hollow conical needle 30.

PS3996CZ

The use of the cartridge 5, which moves together with the hollow conical needle 30, makes it possible to form an end drop 20 of polymer solution or melt when anchoring the other end of the formed polymer fiber 4, which serves to securely anchor the end of this fiber to the surface of the substrate 1; material to form the further polymeric fiber (s) 4. The fiber 4 subsequently formed from the material of the end drop 20 may then be parallel to the fiber formed in the previous stroke of the hollow conical needle 30 or may be arranged in any other desired manner. The hollow conical needle 30 can thus be reciprocated by means of a manipulator between two or more points on the surface of the substrate 1, at least one of which a starting drop 2 or an end drop 20 of polymer solution / melt 1 is deposited, forming any fibrous structure between them with parallel or at any angle arranged, optionally intersecting fibers of different polymers and / or diameters and / or lengths.

If necessary, the productivity can be increased by increasing the number of hollow conical needles 30 or other elongate spinning elements 3. At least some of the hollow conical needles can have a common manipulator, resp. drive mechanism, and possibly also cartridge 5. If different hollow conical needles 30 have different cartridges 2 or are connected to different compartments of one cartridge 5, and / or if they have different dimensions and / or shape of their tip and / or outlet opening, it is possible to simultaneously form fibers of different polymers and / or parameters, e.g. diameters.

The movement of the manipulator, in all the variants described above, preferably takes place along an arcuate trajectory T, which in its initial and final phase has a normal direction to the surface of the substrate 1. The manipulator moves with acceleration in the initial phase of its movement and in the final phase of its movement. deceleration, reaching a top speed of 1 to 100 m / min or higher.

The parameters of the formed polymer fibers are then determined by the properties of the spun material and the speed of movement of the spinning element 3, while with suitable choice these parameters can be produced using one type and size of spinning element 3 polymer fibers with length tens of millimeters to units of meters and diameter from 100 nm to 10 pm.

* PS3996EN

In this way, linear or planar structures with the desired orientation of the individual polymeric fibers (the individual fibers are placed next to one another with the desired mutual orientation and possibly also on one another) can be produced on the surface of the sheet (s) 1, and by layering these linear and / or planar structures. possibly with the use of a spatially shaped base 1 or more, in the space of the bases 1 suitably placed in relation to each other, also spatial formations. These formations made of biologically compatible and possibly also biodegradable polymer (eg polycaprolactone - PCL, etc.) are then used mainly as so-called "scaffolds", respectively. carriers for implantation of living cells in the field of tissue engineering and regenerative medicine, where the orientation of their fibers, resp. of its interfiber spaces represents the direction of preferential storage, resp. cell growth, which makes it possible to produce, for example, functional replacements of various tissues with the desired cell orientation, such as muscle, tendon or neuronal tissues, etc. The structures formed in this way can be further modified by possible further mechanical processing, eg translation, folding, etc., linear the shapes are then, for example, twisted into a yarn (see, for example, FIG. 7), etc.

A suitable polymer for the production of polymeric fibers by the process according to the invention in any of its variants is, in particular, a polymer with a relative molecular weight close to or equal to 90,000, a polymer with a relative molecular weight of at least 45,000 being used. Polymer spinnable polymers are, for example, polyvinyl alcohol (PVA). polyvinyl butyral (PVB), polystyrene (PS), poly (methyl methacrylate) (PMMA), polycaprolactone (PCL), polyurethane (PU), etc. A suitable mixture of these polymers or a copolymer of at least two of them, or a modified variant, can also be spun. any of them. For the production of devices intended for medical use, the condition is the use of biologically compatible and possibly also biodegradable polymers approved for medical use. At least one suitable substance or its precursor can be added to the polymer solution or melt, which is incorporated / incorporated into its structure during the formation of the fiber 4 and provides it with suitable mechanical parameters (e.g. increases its strength, abrasion resistance, etc.), or gives it special properties (eg antimicrobial properties, etc.).

‘PS3996EN

The polymer or polymer mixture melts to form a melt. To form a solution, it is dissolved in an appropriate solvent, and when dissolved in an organic solvent (e.g., chloroform), the solvent is preferably stabilized with a suitable substance (e.g., ethanol).

During the formation of the polymer fibers by the method according to the invention, different materials or different variants of one material with different molecular weights can be suitably combined, as well as fiber diameters, which makes it possible to adjust the rate of biological or other degradation of individual parts of the formed structure. from a material with a lower molecular weight and possibly a smaller diameter they degrade faster.

The process for the production of polymeric nanofibers according to any of the described variants takes place under essentially any conditions, and in comparison with, for example, electrostatic spinning, it is not bound, resp. its performance is not significantly affected by the current physico-chemical conditions in the spinning space. However, in order to limit the drying of the solution or the solidification of the melt in the droplets 2, 20, it is advantageous if at least the formation of these droplets 2, 20, or the whole polymer fiber production process takes place in an atmosphere with controlled gas composition and / or temperature.

The following are specific examples of the production of polycaprolactone (PCL) fibers, a biocompatible polymer approved for medical use, polyvinyl alcohol (PVA) and polyvinyl butyral (PVB).

Example 1

Dissolution of polycaprolactone (PCL) with an average molecular weight of 90,000 in a chloroform-ethanol solvent system (7: 3 ratio) gave a solution containing 24% by weight of polycaprolactone. This solution was stored in the interior of the cartridge 5, which was divided by a piston 6 into two parts, one of which was connected to the cavity of a hollow conical needle 30 with a 0.62 mm diameter outlet and the other to a source of compressed air. With a pressure pulse of 0.6 bar with a length of 0.15 s, a drop 2 of this solution with a volume of 0.065 μΙ was extruded on an adhesive substrate 1 made of black paper (black was chosen as a contrast for the fibers formed). By means of the manipulator, the cartridge 5 with the hollow conical needle 30 was then moved along an arcuate path T to an end point on the surface of the substrate 1 at a distance of 80 mm from the drop 2, the maximum height of the tip of the hollow conical needle 30 above the surface of the substrate 1 being 16 mm. At the end point of the trajectory T, an end drop 20 of polymer solution was formed on the surface of the substrate 1 in the same way as drop 2, and fibers of the same polymer were formed in both phases of reciprocating hollow conical needle 30. After forming every 100 fibers, hollow conical needle was formed. 30 by means of a manipulator moved by 0.5 mm in the direction perpendicular to the plane of the trajectory T, where a new starting drop 2 and a new end drop 20 were formed. The manipulator moved with its acceleration for the first 500 ms with acceleration. / min began to move with deceleration and moved for another 1500 ms.

In this way, a linear structure formed by polycaprolactone nanofibers was formed, the electron scanning microscope (SEM) images of which at 480x, 1000x, 3000x and 5000x magnifications are shown in Figures 3 to 6.

Fig. 7 is then an SEM image of the linear structure thus formed, which has been additionally twisted by rotating a part of the substrate 1 with the deposited ends of the individual polymeric nanofibers.

In an analogous manner, it is possible to form sheets with polymer fibers arranged in parallel - see, for example, FIG. 8, or with fibers arranged. at any angle to the grid - see, for example, Fig. 9. Above all, these surface shapes can be used, for example, as so-called scaffolds, resp. carriers for storing and culturing living cells, which colonize them preferably in the direction of the interfibrous spaces - see e.g. Figs. 10 to 12, in which SEM images of these structures are seeded with 3T3 mouse fibroblasts, and Fig. 13 is a picture of the structure of Figs. 12 from a fluorescence microscope in which the bright spots represent the nuclei of the cells, and from which the preferred orientation of the cells, resp. direction of scaffold colonization.

Example 2

Dissolution of polyvinyl alcohol (PVA) with an average relative molecular weight of 67,000 in demineralized water formed a solution containing 40%

PS3996CZ hm polyvinyl alcohol. Then, two drops 2, 20 of this solution, 100 mm apart, formed on the surface of the substrate 7 (paper). An elongated spinning element 3 formed by a metal tube with an outer diameter of 0.4 mm was immersed in the initial drop 2 by means of a manipulator, which was then moved along an arcuate trajectory T and immersed in the end drop 20 of the solution. The maximum height of the end of the elongate spinning element 3 above the surface of the substrate 1 was 20 mm. In this way, a polymeric nanofiber was formed between the initial drop 2 of the solution and the final drop 20 of the solution. By repeating this process, further polymeric nanofibers were gradually formed in each phase of the movement of the spinning element 3. During its movement, the manipulator moved for the first 500 ms with acceleration, while after reaching a speed of 9 m / min, it started to move with deceleration and thus moved for another 1500 ms.

After forming the required number of polyvinyl alcohol nanofibers, a solution containing 15% by weight of polyvinyl butyral was formed by dissolving polyvinyl butyral (PVB) having a relative molecular weight of 60,000 in ethanol. This solution was spun in the same way as the polyvinyl alcohol solution and the formed nanofibers were deposited over the polyvinyl alcohol nanofibers to form a planar grid, see Fig. 14, where the lighter fibers are polyvinyl alcohol fibers. ₃ ) and darker polyvinyl butyral nanofibers.

The method according to the invention makes it possible to form essentially any linear, planar or three-dimensional formations with any precisely defined mutual arrangement of the individual polymer fibers with a diameter of 100 nm to 10 [mu] m. After removal from the surface of the substrate 1, these formations are, if necessary, shaped or sized, e.g., cut-out, or further processed, e.g., by rolling, folding, etc., before and / or during or after removal from the substrate 1. it is possible to join the individual fibers or groups of nanofibers of the structure to each other, for example by (partial) melting or etching them (e.g. by steaming a suitable solvent, or by applying an adhesive consisting of the same lower molecular weight polymer and lower solvent content). In another variant of the embodiment, the linear, planar or three-dimensional structures can be applied directly during production to any suitable substrate 1, which is formed directly by a layer * PS3996CZ of material, which is used in the final application together with these fibers. Such a layer can be, for example, a fabric of any type, a plastic or metal foil, a grid or a mesh, a layer of nanofibers, etc.

In one variant of the method for producing a three-dimensional structure comprising polymer fibers with a diameter of 100 nm to 10 μm, the polymer fibers with a diameter of 100 nm to 10 μm formed by the method according to the invention are deposited parallel to each other and / or differently and / or extremes between different parts of a suitably shaped surface. , or between two substrates placed, for example, against each other or in any other spatial arrangement.

When using the spinning element 3 and the substrate 1 of electrically conductive material, it is possible to stimulate the formed fiber 4 with an electric current, when an electrical circuit is closed between the substrate 1, the currently "pulled" fiber 4 and the spinning element 3, into which a high DC voltage source (not shown) supplies a high DC voltage of any polarity, of magnitude in the order of units up to tens of kV. Fiber 4 is the most exposed part of this circuit and the conformations of its macromelluules are thus affected by the action of an external electric field. At the same time, a material structure is created which improves the geometric and mechanical properties of the fiber formed. For safe implementation, it is necessary for the high DC voltage source to be controllable in the sense that the circuit is formed only at a distance of the spinning element 3 from the surface of the substrate 7 greater than the breakthrough distance of the applied high voltage.

Claims (20)

PATENT CLAIMS A method for producing polymer fibers with a diameter of 100 nm to 10 μm, characterized in that a drop (2) of a polymer solution or melt with a volume of at least 0.001 μΙ is formed on the surface of the substrate (1), during or after its formation immerses the end of at least one elongate spinning element (3), on the surface and / or in the cavity of which a part of the polymer solution or melt is caught from this drop (2), after which this spinning element (3) is moved by the manipulator on which it is mounted, and / or moves to another location of the same or another substrate (1) by moving the substrate (1), the polymer solution or melt on its surface and / or in its cavity remaining connected by the solution fiber (4) due to its viscosity and surface tension during this movement. or a polymer melt whose diameter decreases with the droplet (2) on the surface of the substrate (1) as the spinning element (3) and / or the substrate (1) moves, and this fiber (4) decreases with subsequent contact of the end of the spinning element (3) with anchors the surface of the substrate (2), thereby the surface of the substrate (2) forms a polymer fiber with a diameter of 100 nm to 10 μm. Method according to claim 1, characterized in that a drop (2) of polymer solution or melt is formed on the surface of the substrate (1) by applying the polymer solution or melt by an application device or manually. Method according to claim 1, characterized in that a drop (2) of polymer solution or melt is formed on the surface of the substrate (1) by applying a polymer solution or melt by means of a spinning element (3) to which and / or into the cavity the solution or the polymer melt is applied by immersing it in a solution or melt of the polymer in a container. Method according to claim 3, characterized in that a drop (2) of polymer solution or melt is formed on the surface of the substrate (1) by forcing the polymer solution or melt from the polymer solution or melt reservoir through the cavity of the hollow spinning element (3). 5, characterized in that the spinning element (3) moves along a trajectory (T) and the substrate (1) is static. Method according to claim 4, characterized in that the hollow spinning element (3) is mounted on a cartridge (5) and its cavity is connected to the inner space of this cartridge (5) with the stored polymer solution or melt. • PS3996EN Method according to Claim 4 or 5, characterized in that the hollow spinning element (3) is a hollow conical needle (30) whose outlet opening has a diameter of 0.1 to 1.2 mm or a tube with an outer diameter of 0.1 up to 1.5 mm. A method according to any one of the preceding claims, Method according to Claim 7, characterized in that the spinning element (3) is moved along an arcuate trajectory (T). Method according to claim 7 or 8, characterized in that the movement of the spinning element (3) is stopped before contact with the surface of the substrate (1), and continues after at least partial solidification of the fiber (4). Method according to Claim 7, 8 or 9, characterized in that the spinning element (3) is moved at a maximum speed of 1 to 100 m / min. Method according to claim 1, characterized in that the fiber (4) is anchored 15 in the end drop (20) of the polymer solution or melt on the surface of the same or different substrate (1). Method according to claim 5 or 6 and 11, characterized in that an end drop (20) of polymer solution or melt on the surface of the substrate (1) is formed by extruding at least 0.001 μΙ of polymer solution or melt from the inner 20 of the cartridge space (5) by the cavity of the hollow spinning element (3). Method according to Claim 11 or 12, characterized in that at least one polymer fiber with a diameter of 100 nm to 10 μm is formed from the end drop (20) of the polymer solution or melt in the same manner. The method of claim 1, characterized in that during movement 25 of the spinning element (3) or when it is interrupted, a high DC voltage of any polarity is applied to this spinning element (3) and to the electrically conductive substrate (1). The method of claim 1, wherein the polymer is a polymer selected from the group consisting of polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polystyrene 30 (PS), poly (methyl methacrylate) (PMMA), polycaprolactone (PCL), polyurethane (PU), a modified variant of any of them, or any mixture or copolymer of at least two of them. A method of manufacturing a linear or planar structure comprising polymeric fibers with a diameter of 100 nm to 10 μm, characterized in that the polymeric fibers with a diameter of 100 nm to 10 μm formed by any of the methods according to claims 1 to 15 are applied to the surface of the substrate (s) (1). ) are repeatedly placed side by side and / or on top of each other to form a linear or planar structure. A method of manufacturing a sheet or spatial structure comprising polymeric fibers with a diameter of 100 nm to 10 μm, characterized in that the polymeric fibers with a diameter of 100 nm to 10 μm formed by any of the methods according to claims 1 to 15 are applied to the surface of the substrate (s) (1). ) are repeatedly deposited in parallel and / or differently, after which or in the same way, polymer fibers with a diameter of 100 nm to 10 μm are formed from the same or different material, which are deposited on them with a different orientation. A method of manufacturing a spatial structure comprising polymeric fibers with a diameter of 100 nm to 10 μm, characterized in that the polymeric fibers with a diameter of 100 nm to 10 μm formed by any of the methods according to claims 1 to 15 are deposited parallel and / or differently with each other and / or or intermittently between different parts of the surface of one substrate (1) or between two substrates (1). Method according to claim 16 or 17, characterized in that the polymer fibers with a diameter of 100 nm to 10 μm formed by any of the methods according to claims 1 to 15 are anchored at their end on a different substrate (1) than the one on which the starting drop is deposited. (2) the polymer solution or melt from which these fibers are formed. Method according to claim 17, characterized in that the polymer fibers with a diameter of 100 nm to 10 μm formed by any of the methods according to claims 1 to 15 are deposited on a spatially shaped substrate (1).