This non-provisional application claims priority under 35 U.S.C. § 119(a) to Patent Application No. 111133264 filed in Taiwan, R.O.C. on Sep. 1, 2022, the entire contents of which are hereby incorporated by reference.
This application relates to a detection system and method for a migrating cell, applying optics.
The metastasis of cancer is the leading cause of death, and it is closely related to migrating cells 104 shedding from tumor in situ 101, namely circulating tumor cells (CTCs).
In recent years, the development of technologies at home and abroad has mainly focused on the development of detection and capture of CTCs, such that CTC detection has the characteristics of non-invasiveness, direct and accurate detection of tumor cells, real-time detection, monitoring of spread tumor cells in the blood, and early indication of cancer cell spread changes, that is, personalized medicine, such as prognosis, treatment monitoring and selection, is performed via CTC counting and molecular characterization analysis. However, since CTCs are sparse, they are difficult to detect, and the process involves many processing steps, the CTC detection technology still has many limitations in clinical application. At present, common CTC cell detection ways in the market include flow cytometry, immunofluorescence, fluorescence in situ hybridization (FISH), real-time polymerase chain reaction (RT-PCR) and next generation sequencing (NGS). For the flow cytometry, a large number of rapid detection schemes are provided, but due to its low detection sensitivity, a large number of samples are required and cell morphology cannot be observed. The immunofluorescence has the advantages that the cell morphology can be directly observed, the detection sensitivity is high and the speed is fast, but due to the diversity of the cell morphology, there will be subjective differences in judgment due to the heterogeneity of cell antigen expression. FISH provides molecular detection grades, and has the advantages of high stability, high sensitivity and high specificity, but its disadvantages are that a shorter probe has low hybridization efficiency and is susceptible to interference. Since RT-PCR can directly detect RNA of CTC, the sensitivity is high, but it is limited by the problems that RNA is prone to degradation, pollution and interference. NGS can be applied in a wide range of detections, and has high sensitivity and fast speed, but due to its high price, it cannot be popularized, and the cell morphology cannot be observed.
Each of the above detection methods has its own advantages and disadvantages. However, as for technologies currently used, a longer period of time is required for testing, and patients need to go to hospitals and clinics repeatedly, which is both troublesome and time-consuming for residents in some villages and towns lacking medical care. Moreover, the high cost of testing also weakens the willingness of the patients to undergo self-paying examinations, allowing their illnesses to spread. Furthermore, in some detection technologies, the number of CTCs cannot be accurately measured, resulting in low detection efficiency.
In view of this, this application proposes a detection system for a migrating cell. The detection system for the migrating cell, suitable for detecting a labeled sample, the labeled sample including a migrating cell and an immunomagnetic bead combined with the migrating cell, the immunomagnetic bead including a magnetic bead and an antibody embedded into the surface of the magnetic bead, the antibody being combined with a surface antigen of the migrating cell, and the detection system for the migrating cell including a platform; a microchannel, provided on the platform, and configured to allow the labeled sample to flow in it along a flow direction; a magnetic field source, provided outside the microchannel, and configured to provide a magnetic field to the microchannel, and the magnetic field applying a magnetic force to the magnetic bead of the labeled sample, and the magnetic force including at least one magnetic force component and the magnetic force component being opposite to the flow direction; a coherent light source, provided above the platform, and configured to apply coherent light to the microchannel; and an optical sensing module, provided above the platform, and configured to receive interference light caused by the coherent light being reflected by the labeled sample inside the microchannel.
According to some embodiments, the magnetic field source is a coil, and the coil surrounds the microchannel and is configured to provide the magnetic field.
According to some embodiments, the detection system further includes an image processing module, the image processing module calculating the flow velocity of the labeled sample in the microchannel according to the contrast of the interference light, and judging that the migrating cell passes through the microchannel when the value of the flow velocity produces a surge change.
According to some embodiments, the image processing module calculates the flow velocity of the labeled sample in the microchannel according to the following formula:
Where V is flow velocity, T is exposure time, K is contrast, and i and j are pixel coordinates.
According to some embodiments, the pipe diameter of the microchannel is greater than or equal to 10 μm and less than or equal to 50 μm.
According to some embodiments, the wavelength of the coherent light is greater than or equal to 660 nm and less than or equal to 760 nm.
This application further provides a detection method for a migrating cell. The detection method for the migrating cell, configured to detect a migrating cell in a blood sample, the migrating cell including a surface antigen, and the detection method for the migrating cell including the following steps: mixing the blood sample with an immunomagnetic bead to form a labeled sample, the immunomagnetic bead including a magnetic bead and an antibody embedded into the surface of the magnetic bead, and the antibody being combined with the surface antigen of the migrating cell; allowing the labeled sample to pass through a microchannel in a flow direction; applying a magnetic field to the microchannel, the magnetic field applying a magnetic force to the magnetic bead of the labeled sample, and the magnetic force including at least one magnetic force component and the magnetic force component being opposite to the flow direction; applying coherent light to the microchannel; and receiving interference light caused by the coherent light being reflected by the labeled sample inside the microchannel.
According to some embodiments, after mixing the blood sample with the immunomagnetic bead, the method further includes: centrifugally separating and removing the immunomagnetic bead not combined with the migrating cell.
According to some embodiments, after the receiving the interference light caused by the coherent light being reflected by the labeled sample inside the microchannel, the method further includes: the applying a magnetic field to the microchannel to drain the labeled sample, and collecting the migrating cell combined with the immunomagnetic bead and attracted by the magnetic field.
According to some embodiments, the migrating cell is a circulating tumor cell, and an antibody of the immunomagnetic bead is an EpCAM antibody or Her2 antibody.
In the detection method for the migrating cell 104, the blood sample 108 is mixed with the immunomagnetic bead 201 to form the labeled sample (step S02).
In the detection method for the migrating cell 104, the mixture of the labeled samples is allowed to pass through a magnetic field microchannel 202 in a flow direction (step S04).
The magnetic field microchannel 202 is provided on the platform 207, and includes a microchannel 2022 and a magnetic field source 2021. According to some embodiments, the microchannel 2022 is directly or indirectly fixed to the platform 207. By way of examples, the microchannel 2022 is fixed to a fixture of the platform 207 or placed in a preinstalled holding space. According to some embodiments, the magnetic field source 2021 is directly or indirectly fixed to the platform 207. The microchannel 2022 is configured to allow the labeled sample to flow in it along a flow direction. According to some embodiments, the width of the microchannel 2022 only allows one to several migrating cells 104 to pass through to provide good counting and detection conditions, as explained in detail later. The surface of the microchannel 2022 is sufficiently transparent, which is enough for coherent light L1 to penetrate and be sensed by optical sensing module 204. By way of examples, the microchannel 2022 is made of silicon dioxide, quartz, silicon crystal, polymethyl methacrylate, polydimethylsiloxane, polystyrene or polycarbonate. According to some embodiments, the microchannel 2022 can push or pull the labeled sample by using a vacuum pump or peristaltic pump, or drive the flow of the microchannel 2022 by employing gravity, concentration gradient, electrical potential difference and other ways. The magnetic field source 2021 may be a magnet, an electromagnet, or a coil. The magnetic field source 2021 is provided outside the microchannel 2022, and configured to provide a magnetic field to the microchannel 2022, and the magnetic field applies a magnetic force to the immunomagnetic bead 201 of the labeled sample. The magnetic force includes at least one magnetic force component and the magnetic force component is opposite to the flow direction of the labeled sample inside the microchannel 2022. According to some embodiments, the magnetic field source 2021 employs an electromagnet or coil energized with direct current to provide a stable magnetic field direction B, ensuring that the magnetic field direction B and a flow direction F of the microchannel 2022 keep a fixed relative relationship to avoid turbulence inside the microchannel 2022. According to some embodiments, the magnetic field source 2021 is the coil surrounding the microchannel 2022. In this way, a uniform magnetic field provided by the coil avoids that turbulence is caused by different flow velocity at different positions inside the microchannel 2022, thereby achieving the effect that the migrating cells 104 gradually pass through. The magnetic force component may refer to a projection on a magnetic force vector vs. a flow direction vector of the microchannel 2022. By way of examples, if the flow direction vector of the microchannel 2022 is (1,0) and the magnetic force vector is (−3, −4), the angle therebetween is 233°, and the magnetic force includes a magnetic field component (−3,0) opposite to the flow direction vector (1,0) of the microchannel 2022. In this way, the immunomagnetic bead 201 with magnetic susceptibility and its labeled migrating cell 104, when flowing through the magnetic field, are subjected to magnetic force and decelerate.
In the detection method for the migrating cell 104, the coherent light L1 is applied to the microchannel 2022 and the interference light caused by the coherent light L1 being reflected by the labeled sample inside the microchannel 2022 is received (step S05). According to some embodiments, the coherent light source 203 used for emitting the coherent light L1 may be a laser light source, for example a red He—Ne laser with a wavelength of 632 nm or a green laser with a wavelength of 532 nm. The coherent light source 203 is provided above the platform 207. According to some embodiments, the coherent light source 203 is directly or indirectly fixed to the platform 207. By way of examples, it is provided on a wall surface directly connected to or a top surface indirectly connected to the plate of the detection machine. Preferably, the coherent light source 203 may employ red laser light with a wavelength greater than or equal to 650 nm and less than or equal to 720 nm to match the absorbance of hemoglobin, as explained in detail later.
When the labeled sample inside the microchannel 2022 begins to flow, the spot undergoes a light and dark change. For pixels in fixed positions, within a pixel range as box-selected in the bottom left corner of
Where V is the flow velocity, T is exposure time, K is the contrast, and i and j are pixel coordinates of a two-dimensional image. Therefore, the faster the flow velocity of the labeled sample per unit exposure time is, the smaller the measured spot contrast is. Conversely, an image processing module 205 receives the spot image 206 sensed by the optical sensing module 204. When the image processing module 205 judges that the spot contrast suddenly increases, representing that the flow velocity of the labeled sample inside the microchannel 2022 suddenly decreases.
According to some embodiments, since the labeled sample is mostly composed of the red blood cells 105, the leading cause of the spot image 206 is the red blood cells 105. That is, in the detection method for the migrating cell 104, the migrating cell 104 labeled with the immunomagnetic bead 201 is decelerated by using the magnetic field, and the red blood cell 105 in the labeled sample is blocked and decelerated at the same time. The optical sensing module 204 detects the constructive interference light L2 caused by the coherent light L1 being reflected by a large number of red blood cells 105, thereby obtaining the spot image 206. From this point of view, the absorbance of the red blood cell 105 to the coherent light L1 has a key influence on imaging of the spot image 206.
According to some embodiments, a cell capture module can be further attached to the microchannel 2022, and the cell capture module may include a magnetic field source and a cell collection region. The magnetic field source of the cell capture module may be, but not limited to, a magnet, an electromagnet or a coil. The magnetic field source of the cell capture module can be placed or fixed around the microchannel 2022. The cell collection region is configured to collect the migrating cells 104, and the cell collection region may be a holding space inside the microchannel 2022 or an external container. After the migrating cells 104 pass through the magnetic field microchannel 202 and counting is completed, the magnetic field generated by the magnetic field source of the cell capture module attracts these migrating cells 104 labeled with the immunomagnetic beads 201 and the migrating cells are drained to the cell collection region. After that, the cell morphology can be further judged with a cell morphology detection method. In this way, in the detection method for the migrating cell 104, a rapid and accurate preliminary assessment is firstly performed on the content of the migrating cells 104 in a specimen. When it is judged that the content is abnormal, these migrating cells 104 are then captured to further determine the cell morphology, and the detection speed and accuracy are balanced by graded detection.
In summary, in the process of cancer treatment, the most daunting is often the metastasis of cancer, which if not detected early, the recurrence rate and mortality rate of cancer will be significantly increased. If the cancer metastasis is detected and treated early, the subsequent risk caused by the cancer metastasis can be greatly reduced. Therefore, providing fast, accurate, affordable, and widely available early screening systems has become a major development focus for cancer treatment. In the detection method for the migrating cell 104 in this application, counting detection of single cells is performed by applying the microchannel 2022, and thus, the detection can be completed by only a very small amount of blood samples 108. The applicant finds from the study that the detection method for the migrating cell 104 can be performed only by drawing 8-10 ml of whole blood. Furthermore, the microchannel 2022 can be manufactured in mass through chip processing, thereby effectively reducing production costs. Compared with a traditional way for directly performing comprehensive cell number and cell morphology assessment on the whole blood, the detection method for the migrating cell 104 provides a rapid screening scheme: firstly, specimens of low-risk patients with lower content of migrating cells 104 are screened and excluded by using cell counting, and then samples of the migrating cells 104 in the specimens of high-risk patients are provided for further standardized judgment by using a traditional detection device. Overall, the detection method for the migrating cell 104 improves the detection efficiency and allows for widespread rapid screening for a large number of early cancer patients, thereby reducing the prevalence of metastatic cancer.
Although the application has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope of the application. Persons having ordinary skill in the art may make various modifications and changes without departing from the scope and spirit of the application. Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments described above.
Number | Date | Country | Kind |
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111133264 | Sep 2022 | TW | national |