A sachet for polymers concentrating biological fluids

Abstract

The invention relates to a sachet that prevents the technical problems caused by the presence of spaces between the polymers swelling spherically, which polymers reduce the volume of the fluid by removing water and other small molecules from the body fluid by means of elastic hydrophilic polymer meshed structures.

Description

[0001] A SACHET FOR POLYMERS CONCENTRATING BIOLOGICAL FLUIDS

[0002] TECHNICAL FIELD

[0003] The invention relates to a sachet that prevents the technical problems caused by the presence of spaces between the polymers swelling spherically, which polymers reduce the volume of the fluid by removing water and other small molecules from the body fluid by means of elastic hydrophilic polymer meshed structures.

[0004] PRIOR ART

[0005] The most important tool in the laboratory diagnosis of infectious diseases is the detection of infectious agents in the fluid biological samples from patients, such as blood, urine and mouthwash. Diagnostic methods inherently use only a very small amount of the sample from the patient. Therefore, collecting the infectious agents from the samples in a small volume and using this concentrated sample in diagnostic tests is of great importance in increasing the test sensitivity. In addition, biological samples may contain substances that interfere with the functioning of diagnostic methods based on nucleic acid amplification, such as polymerase chain reaction (PCR). Removing these substances from the medium is important for such diagnostic tests to function properly.

[0006] The most widely used method to increase the sensitivity of detection of infectious agents in fluid biological samples is centrifugation of fluids to precipitate and concentrate microorganisms. However, centrifugation is a time-consuming process and increases the risk of transmission of disease-causing organisms during these processes. In addition, while infectious bacteria, fungi and parasites can be precipitated and concentrated by centrifugation, viruses cannot be directly concentrated by precipitation as they are much smaller than other organisms.

[0007] Another method of concentrating biological fluids is the filtration method. With filtration, bacteria and fungi can be concentrated as they cannot pass through the pores and remain on the filter, but viruses of small size can easily pass through the filter and cannot be concentrated by the filtration method. The prior art includes a method that reduces the volume of fluid in the medium by removing water and other small molecules by means of elastic polymer networks, thereby concentrating infectious agents, including viruses, in biological samples. The three-dimensional cage-like structures of elastic polymers used in this method capture small molecules, while the volumes of the meshed structures expand. Meanwhile, the size of the pores formed on their surface ensures that infectious agents, including viruses and their large molecules, cannot enter this three-dimensional structure and become concentrated in the small amount of fluid that remains outside. The fluid containing the infectious agents remaining outside these structures is then removed and used for diagnostic tests such as microscopy, culture, nucleic acid amplification and immunological tests. However, it is difficult to keep the swelling polymers under control during this process. The swelling of the polymers beyond the desired volume can cause all the fluid in the medium to be absorbed and the sample volume to become too small to be taken.

[0008] Concentrating biological fluids with elastic polymer beads that absorb water and small molecules increases the sensitivity of diagnostic tests. A minimum sample volume is required for each diagnostic test. Ideally, the biological fluid sample is reduced to this minimum volume and concentrated. Thus, as a result of the concentration process, a sufficient amount of sample remains for testing and at the same time the highest possible level of macromolecules and microorganisms is achieved. The volume of sample that is desired to remain in the medium after concentration can be achieved in part by adjusting the amount of elastic polymer beads added to the biological fluid. However, the osmolarity of the biological fluid, i.e. the amount of molecules it contains other than water, greatly affects the amount of fluid to be captured by the beads. While the same amount of elastic polymer beads cannot sufficiently absorb and concentrate high osmolarity samples, they can absorb too much of low osmolarity samples, causing the samples to reduce below the minimum amount required for the test or even dry out completely. For example, urine is a biological fluid with a highly variable osmolarity depending on the amount of fluid a person has taken that day. Therefore, it is impossible to concentrate all urine samples equally with the same amount of elastic polymer beads. The polymer beads used for fluid removal have a spherical structure. Therefore, when the sample volume decreases significantly after concentration, a significant portion of this sample remains in the spaces between the beads, and this portion of the sample, which contains the molecule or microorganism to be analyzed by the test in the highest concentration, cannot be reached.

[0009] Another difficult aspect of the concentration process with polymer beads is that while taking the concentrated sample with a pipette, these beads sometimes enter the pipette tip and clog it, making it difficult to take the sample.

[0010] Patent No. US2003095997 relates to a vacuum sample collection container used for separating blood into blood cells and plasma or serum. In the said patent, the flow path blocking element swells when it comes into contact with plasma or serum, thus blocking the channel. Therefore, the amount of channel blocking elements required varies depending on the volume of the channel to be blocked, the swelling rate of the channel blocking element and the swelling velocity.

[0011] Patent No. CN 1984989 relates to devices and methods for removing target reagents from samples. In the said patent, the porous matrix comprises natural fibers, synthetic fibers or a combination of both.

[0012] As a result, the aforementioned disadvantages have made it necessary to offer a novelty in the relevant technical field in order to concentrate water and other small molecules from the body fluid at the exact desired rate by the elastic hydrophilic polymer meshed structures, resulting in an ideal amount of sample.

[0013] SUMMARY OF THE INVENTION

[0014] The present invention is a sachet to eliminate the above-mentioned disadvantages and to introduce new advantages to the related technical field, which prevents absorption of more fluid than desired by polymers that reduce the volume of the fluid by removing water and other small molecules from the body fluid by means of elastic hydrophilic polymer meshed structures, and prevents concentrated samples from remaining in the dead space between the spherical polymer beads. An object of the invention is to provide a sachet that reduces the volume of biological fluids used for disease diagnosis, thus concentrating the large molecules and microorganisms in the sample.

[0015] Another object of the invention is to set out a tear-resistant sachet that traps polymer beads capturing water and small molecules.

[0016] Another object of the invention is to set out a sachet that prevents the polymers absorbing fluids from expanding beyond a certain volume.

[0017] Another object of the invention is to set out a sachet, which compresses the elastic polymer beads with a volume limitation as they absorb water and small molecules and expand, enables the spherical beads to form flat surfaces pressing against each other, thus allowing the concentrated fluid remaining between the beads to come out of the sachet.

[0018] DETAILED DESCRIPTION OF THE INVENTION

[0019] In this detailed description, the subject matter of the invention relates to a sachet for preventing excessive swelling and fluid absorption of polymer beads that reduce the volume of the fluid by removing water and other small molecules from biological fluids by means of elastic hydrophilic polymer meshed structures, and is described only by way of examples for a better understanding of the subject matter without any limiting effects.

[0020] The relevant technical field includes a method that reduces the volume of fluid in the medium by removing water and other small molecules by means of elastic polymer networks, thereby concentrating infectious agents, including viruses, and their large molecules such as nucleic acids and proteins in biological samples. The three- dimensional cage-like structures of elastic polymers used in this method capture small molecules, while the volumes of the meshed structures expand. Meanwhile, the size of the pores formed on their surface ensures that infectious agents, including viruses and, if they are disintegrated, their large molecules, are not allowed to enter this three- dimensional structure and become concentrated in the small amount of fluid that remains outside. However, the uncontrolled swelling of the polymers used in this method sometimes causes more fluid absorption than desired, leaving not enough sample to be tested.

[0021] The subject matter of the invention relates to a sachet for preventing uncontrolled swelling of the polymers used in the method with the components contained therein.

[0022] In order to control the swelling process of the polymers and to facilitate their use, the sachet according to the invention may contain one or more components. These component(s) provide technical properties for the sachet, such as chemical and biological compatibility, durability, flexibility and functionality.

[0023] The sachet may contain at least one of plastic, paper, textile and other polymers as a component. If preferred, the sachet can be a composite material containing at least two of these material groups.

[0024] The sachet contains at least one polymer as a component; the said polymer is at least one from the group of polyvinyl chloride (PVC), silicone, polytetrafluoroethylene (PTFE), polypropylene (PP), elastomer, polycarbonate.

[0025] The sachet preferably contains at least one paper-based component; the said paperbased component may be at least one from the group of waste or industrial papers.

[0026] In a preferred embodiment, the sachet contains at least one textile product; it may contain at least one from the group of “nonwoven”, “woven”, knitted fabrics as the said textile product.

[0027] In a preferred embodiment thereof, these materials, which are used as sachets, are biodegradable.

[0028] The sachet according to the invention has a filter feature and is tear-resistant so as not to leak out the elastic polymers inside. These materials ensure that polymers absorbing the fluids are retained in the sachet.

[0029] The volume of the sachet is adjusted to be the total volume of fluid intended to be absorbed from the biological fluid. When the polymer beads swell and reach this volume, they cannot absorb more fluid as they are limited by the sachet, so that the desired amount of concentrated fluid is left outside the sachet.

[0030] The polymer beads used to concentrate the fluid assume a spherical shape when they expand by absorbing the fluid. When these spheres contact each other, the concentrated sample remains in the space between them, making it difficult to reach this sample. An important feature of the sachet is that when the elastic polymer beads reach the highest possible volume as they expand, they cannot expand any further, resulting in a pressure being exerted on the elastic beads. This pressure compresses the elastic beads, disrupting their spherical structure and creating flat surfaces between the beads, thereby eliminating the dead spaces. Thus, the fluid in between, which contains the concentrated sample, is removed from the sachet and becomes easily accessible for the tests.

[0031] The sachet according to the invention contains at least one elastic polymer bead which enables the concentration of large molecules and microorganisms. These polymer beads absorb water and other small molecules in biological fluids, while molecules and microorganisms that are too large to enter through their pores are left outside in the concentrated fluid. The said elastic polymer bead includes at least one from the group of polyacrylamide, polyacrylic acid, polymethacrylate and its derivatives, dextran, agar, agarose, gelatin, glycogen and hydrophilic polymers.

[0032] The sachet according to the invention controls the expansion of polymers that absorb fluid and prevents these polymers from enlarging beyond a certain volume. It increases the sensitivity of the concentration process due to this feature.

[0033] The macromolecules intended to be concentrated with the sachet according to the invention are essentially proteins, nucleic acids, lipids, polysaccharides and all kinds of antigens larger than 0.5 kD. The properties of the sachet for concentrating such macromolecules can be listed as follows:

[0034] - it must not react with the macromolecules and polymers targeted by the sachet and must be able to retain the polymer beads without disrupting or affecting them. - the sachet must be able to maintain its physical integrity and be resistant to any tearing or leakage.

[0035] - biocompatible and inert materials must be preferred.

[0036] - the sachet must be flexible enough to withstand the expansion of the swelling polymer beads, but must also resist excessive expansion and deformation.

[0037] - the sachet must prevent the elastic polymer beads from becoming spherical by applying pressure thereon as they expand by absorbing fluid, thus preventing the concentrated sample from remaining therebetween.

[0038] The sachet according to the invention can be produced in desired sizes and can enable the concentration process in containers of different sizes and shapes suitable for fluid absorption.

[0039] The diagnostic tests used in a preferred embodiment of the sachet according to the invention are used for microscopic examination, culture; immunochromatographic tests and immunological tests and antigen and antibody detection; nucleic acid amplification methods, in particular polymerase chain reaction, loop-dependent amplification, strand displacement amplification, rotating circle amplification, and detection of the nucleic acid of infectious agents.

[0040] The scope of protection of the invention is set out in the appended claims and shall in no way be limited to what is described in this detailed description for illustrative purposes. Indeed, it is clear that a person skilled in the art can come up with similar embodiments in light of the foregoing description without departing from the main theme of the invention.

Claims

CLAIMS1. A sachet suitable for use in the health sector, which prevents polymers from swelling excessively and applies pressure to the polymers when they expand, thereby preventing dead spaces between them, which polymers reduce the volume of the fluid by removing water and other small molecules from the body fluid by means of elastic hydrophilic polymer meshed structures, thereby concentrating large molecules and microorganisms.

2. A sachet according to claim 1 , wherein it contains at least one polymer component.

3. A sachet according to claim 2, wherein it contains at least one from the group of polyvinyl chloride (PVC), silicone, polytetrafluoroethylene (PTFE), polypropylene (PP), elastomer, polycarbonate as a polymer.

4. A sachet according to one of the preceding claims, wherein it contains at least one paper-based component.

5. A sachet according to one of the preceding claims, wherein it contains at least one textile product.

6. A sachet according to claim 5, wherein it contains at least one from the group of “nonwoven”, “woven”, knitted fabrics as a textile product.

7. A sachet according to one of the preceding claims, wherein it contains at least one elastic polymer bead for concentrating large molecules and microorganisms.