Recently, DeepTech held the "DeepTech Innovation Week 2022" series of forums. This event consists of six sub-forums, including five "cutting-edge technology forums" - Synthetic Biology Forum, Advanced Molecular Diagnostics Forum, Cell and Immunotherapy Forum, Advanced Computing Forum and Intelligent Computing Forum. A "special forum" - [MEET35 Innovators Talk] and "Bio-X" new crown cutting-edge seminar. Focusing on the most cutting-edge technology tracks, nearly a hundred scientists and technology business leaders were invited to participate. Through this event, the path from scientific research to industrial application, and from laboratory to clinical practice has been further opened.
At the Molecular Diagnostics Forum on June 24, Xu Xiaonan, founder of Dapu Biotechnology, gave a presentation titled "Searching for Needles in the Sea: How Droplet Microfluidics Leads the Next Generation of Bioindustry" .
Dr. Xu introduced in detail how droplet microfluidic technology has reshaped the fields of gene detection and molecular diagnosis, and shared the underlying logic and related product applications of the droplet microfluidic technology platform built by Dap Biotech.
The so-called droplet microfluidic technology refers to a cutting-edge technology that generates and controls millions of nanoliter to picoliter droplets in a closed microchannel network, which can significantly speed up biological and medical research and reduce the cost of Sample consumption has built a new platform for biological and medical research.
The development and challenges of droplet microfluidic technology
In the 1990s, microfluidic technology was widely used in the fields of biology, chemistry and medical research because of its precise sample processing and ability to accelerate biochemical reactions. Microfluidics refers to a technology that controls fluids in a micron-scale space. This technology can shrink the basic functions of chemistry, biology and other laboratories onto a chip of several square centimeters, so it is also called on-chip. Lab on Chip.
Compared with traditional detection technology, microfluidic technology integrates the basic operations of biochemical experiments such as sample reaction, preparation, separation, and detection into a very small chip, with controllable fluid forming a network from microchannels throughout the microfluidic The control system not only realizes various functions of conventional biochemical laboratories on a smaller scale, but also reduces the consumption of reagents for analysis and detection, speeds up the reaction speed, improves the reaction efficiency, and makes the experiment more controllable.
In recent years, with the accumulation of traditional microfluidic technology, droplet microfluidic technology, which uses two immiscible liquid phases to produce dispersed microdroplets for experimental operations, has developed rapidly. Microdroplets, also known as "microreactors," allow biochemical reactions to occur in microscopic droplets ranging from nanoliters to picoliters.
By combining microfluidic technology with micro-droplet technology, droplet microfluidic technology not only improves the detection sensitivity, but also greatly increases the reaction flux, realizing the transformation of the reaction flux from 1 to 107 , It provides a new platform for biological testing and new drug research and development. droplet microfluidic technology has many technical advantages, including small size, fast generation speed, high throughput, uniform size, closed system, and good monodispersity.
Figure 丨 Development of microfluidic technology (source: Dap Bio)
Take the detection of biomarkers commonly used in the field of biomedicine as an example: reliable detection of nucleic acids, proteins, single cells or small molecules in human tissues or biological fluids. Testing can be used to confirm or predict diseases and disease states. Therefore, highly sensitive biomarker detection is crucial in various applications including disease diagnosis, treatment, and drug screening. Unfortunately, for many diseases, the abundance of the biomarker in human samples is low, making traditional detection methods unable to accurately detect and screen.
Droplet microfluidic devices can discrete large volume samples into thousands to millions of microdroplets - each microdroplet serves as an isolated reaction chamber, isolating target molecules in each reaction chamber The reaction proceeds independently in the medium - thus having the potential to achieve highly sensitive detection.
After all, a significant reduction in volume contributes to an equivalent reduction in background and a dramatic increase in the concentration of the target biomarker, which in turn increases the signal-to-background ratio of each separation reaction and, at the same time, independent reaction units, It also avoids mutual interference between reactions, thereby increasing the overall sensitivity of the assay. The qualitative change brought about by this quantitative change is why droplet microfluidic technology will lead the upgrading of the biological industry.
In addition, droplet microfluidic technology also has broad application prospects in the field of medical research and development. First of all, it can be used for rapid monoclonal antibody screening , which shortens the traditional monoclonal antibody screening time from 3 months to one day: traditional hybridoma and single B cells, nanobody screening technology not only has a heavy workload, but also has a long cycle. And the cost is high.
droplet microfluidic technology can quickly package 105-106 cells into a nano-upgraded reaction detection system, using Droplet ELISA to quickly screen out high-expressing cell lines within a few hours after cell packaging, replacing the traditional microwell plate ELISA Monoclonal screening compresses the screening work of previous weeks into one day, and can screen hybridoma cells, single B cells or phages that secrete target antibody molecules more accurately and efficiently.
Secondly, it can be used to optimize the target of cell therapy. For example, in TCR-T therapy, after TCR transcription, a large number of T cells need to be screened to find the correct TCR-T cell clone. The traditional method is not only cumbersome, Time consuming and expensive.
is based on microfluidic droplet sorting technology. Reporter genes are introduced during T cell engineering, and then packaged into microdroplets simultaneously with target tumor cells. Then, individual TCR-T cells can be monitored in real time based on the fluorescence signal of the reporter gene. By identifying the activation status of target tumor cells and screening out functional TCR-T cells, the TCR screening prototype based on microfluidic droplet sorting technology provides an innovative tool to promote the development of immunotherapy screening and T cell therapy.
In addition, it can build a new platform for drug delivery and release, providing new research directions: for example, using droplet microfluidic technology to evaluate drug uptake, disappearance and cytotoxicity in cells, and in single cells and multiple A droplet microfluidic platform suitable for drug screening was established in the interaction of cells.
Of course, there are also many challenges in droplet microfluidic technology. First of all, as one of the core components of droplet microfluidic technology, the design and production of microfluidic chips is very critical. At present, polydimethylsiloxane (PDMS) and soft lithography technology are widely used in the preparation of microfluidic chips. However, in order to further realize commercial production and clinical application, cheaper and stable chip production materials are needed, and Simpler and more convenient chip processing technology also requires further research and exploration.
Secondly, the droplets produced by droplet microfluidics are very small, fast, and numerous. How to quickly detect and analyze a large number of microdroplets is also a difficulty.
Finally, large-scale integration is a significant advantage of microfluidic chips. However, how to integrate modular droplet microfluidic units and upstream and downstream functional units into a multifunctional microfluidic platform on a large scale and achieve automated and intelligent operations still requires further efforts and research.
Creating industrial-grade solutions for biopharmaceuticals
In 2018, Dapu Biotech was incubated on the bank of the beautiful Clear Water Bay - Hong Kong University of Science and Technology.As the founder of Dapu Biotech, Dr. Xu Xiaonan, who graduated from the Hong Kong University of Science and Technology, has been deeply involved in the field of droplet microfluidics for nearly ten years. He has extensive experience in droplet microfluidics technology, chip design, biochemistry , computers, mechanics and optics He has rich industry-university-research experience in highly interdisciplinary fields, has published dozens of related papers, and holds dozens of related patents.
Unlike most start-ups that focus on the application level, Dapu Biotech chose a difficult path at the beginning of its establishment and is committed to becoming an upstream company that masters the underlying core technologies by integrating biology, chemistry, computers, optics, automation Talents in fields such as droplet microfluidics build industrial-level solutions for biopharmaceuticals based on the underlying technology of droplet microfluidics.
Picture | Xu Xiaonan, founder of Dap Bio (Source: Dap Bio)
The first is the manipulation module of micro droplets. is different from using pipette in the laboratory to mix and analyze samples. Microfluidic technology generates millions of droplets. How to achieve one-to-one precise control among millions of droplets? , which involves very complex fluid control and optical-mechanical automation. In the early days, Dr. Xu Xiaonan's team did a lot of work at the Hong Kong University of Science and Technology and published a series of academic papers and patents, laying a solid foundation.
The second step is the design and large-scale mass production of microfluidic chips. In the past three years, Dapu Biotechnology has successfully solved the problem of chip design and mass production. It has its own microfluidic chip production line and has opened up all aspects of prototype design, mold opening, replication molding, post-processing and quality control. This is also the core competitiveness of Dapu Biotech, which can quickly and efficiently iterate products, control costs, and strictly control quality.
(Source: Dap Bio)
Based on the built underlying technology , Dap Bio has developed three industrial-level technology platforms .
The first is a single-cell high-throughput screening platform. The principle of is to predict the fluorescence signal of microdroplets, which can identify the genome or proteome information of cells wrapped in microdroplets or the molecular information secreted by cells, and then classify a certain group into groups through the function of dielectrophoresis Functional cells are selected, and 107-level microdroplet sorting can be achieved in a single time. This system is widely used in monoclonal antibody screening, cell therapy target optimization and other fields, and can significantly shorten the screening process.
The second one is the single cell sequencing library construction platform. The Xinghai single-cell library construction platform independently developed by Dapu Biotech is based on patented pressure-insensitive droplet generation and hydrogel-encoded microsphere technology, which can quickly realize the construction of single-cell sequencing libraries for 1-4 samples. The principle of
is to code each microdroplet. When the cells are lysed in the microdroplet, the nucleic acid sequence on the coded microsphere is introduced into the cDNA sequence, directly adding molecular tags to the genome of each cell. , when analyzing sequencing data, genes are returned to individual cells based on molecular tag information to achieve genetic information analysis with single-cell level accuracy.
The third is a digital PCR platform. The third generation digital PCR technology independently developed by Dapu Biotech has higher precision, sensitivity and anti-interference compared to real-time fluorescence quantitative PCR. can accurately quantify nucleic acid molecules and is especially suitable for samples with complex matrices. Detection, such as the detection of residual DNA in the production and quality inspection of biopharmaceuticals.
In the production or quality inspection of cell and gene therapies, biosimilars , and vaccine drugs, there are four main methods for detecting residual DNA in preparations in the current pharmacopoeias of various countries: hybridization method, threshold method, fluorescent dye method, and PCR method.Due to its extremely high sensitivity, specificity and accuracy, the digital PCR method can provide the biopharmaceutical industry with a more precise and reliable detection method in process research and finished product quality control. It has gradually become the preferred detection method for various biological products manufacturers. .
(Source: Dap Bio)
About Dap
Dap Biotechnology Co., Ltd. was incubated at the Hong Kong University of Science and Technology and was co-founded in 2018 by a number of returnee Ph.D. It has R&D centers in Shenzhen, Jiaxing, and Hong Kong, with a R&D team of nearly 100 people. It has established a GMP factory integrating the production of microfluidic chips, instruments and reagents.
The company focuses on applying droplet microfluidic technology to the field of precision medicine, and is committed to becoming a complete solution provider integrating the R&D and production of microfluidic chips, instruments, and reagents. The company independently develops and produces two major technology platforms: digital PCR system and single-cell omics system, which are used in cancer research, early cancer screening, targeted therapy, non-invasive prenatal diagnosis, quantitative virus detection, high-throughput drugs and Antibody screening and other fields.
