Professor Klavs F. Jensen | |
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Born | 1952 |
Nationality | American |
Alma mater | University of Wisconsin Technical University of Denmark |
Known for | Flow chemistry Microfluidics Chemical Reaction Engineering |
Awards | National Academy of Engineering (2002) National Academy of Sciences (2017) |
Scientific career | |
Fields | Chemical engineering |
Institutions | University of Minnesota Massachusetts Institute of Technology |
Doctoral advisors | W. Harmon Ray |
External videos | |
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“Klavs Jensen on Accelerating Development and Intensification of Chemical Processes” “Klavs Jensen – 3eme Reunion Plenary Lecture” |
Klavs Flemming Jensen [1] (born August 5, 1952) [2] is a chemical engineer who is currently the Warren K. Lewis Professor at the Massachusetts Institute of Technology (MIT). [2]
Jensen was elected a member of the National Academy of Engineering in 2002 for fundamental contributions to multi-scale chemical reaction engineering with important applications in microelectronic materials processing and microreactor technology.
From 2007 to July 2015 he was the Head of the Department of Chemical Engineering at MIT. [3]
Jensen received his chemical engineering education from the Technical University of Denmark (M.Sc., 1976) and University of Wisconsin–Madison (PhD, 1980). [2] [4] [5] [6] [7] Jensen's PhD advisor was W. Harmon Ray. [7] In 1980, Jensen became assistant professor of chemical engineering and materials science at the University of Minnesota, before being promoted to associate professor in 1984 and full professor in 1988. [8] In 1989, he moved to the Massachusetts Institute of Technology. [8]
At the Massachusetts Institute of Technology, Professor Jensen has been the Joeseph R. Mares Career Development Chair in Chemical Engineering (1989–1994), the Lammot du Pont Professor of Chemical Engineering (1996–2007), and the Warren K. Lewis Professor of Chemical Engineering (2007– present). [9] Klavs served as Head of the MIT Department of Chemical Engineering from 2007–2015. [10] In 2015, Professor Jensen became the founding Chair of the scientific journal Reaction Chemistry and Engineering by the Royal Society of Chemistry focused on bridging the gap between chemistry and chemical engineering. [11]
Jensen's research revolves around reaction and separation techniques for on-demand multistep synthesis, methods for automated synthesis, and microsystems biological discovery and manipulation. [5] He is considered one of the pioneers of flow chemistry. [12]
Jensen, Armon Sharei and Robert S. Langer were the founders of SQZ Biotech. [13] [14] The trio, together with Andrea Adamo, developed the cell squeezing method in 2012. [15] It enables delivery of molecules into cells by a gentle squeezing of the cell membrane. [15] It is a high throughput vector-free microfluidic platform for intracellular delivery. [15] It eliminates the possibility of toxicity or off-target effects as it does not rely on exogenous materials or electrical fields. [15]
Jensen, along with Timothy F. Jamison, Allan Myerson and coworkers, designed a refrigerator-sized mini factory to make clinic-ready drug formulations. [16] The mini factory can make thousands of doses of a drug in about two hours. [16] The factory can allow sudden public health needs to be more easily addressed. [16] It can also be useful in developing countries and for making medicines with a short shelf life. [16] Chemical & Engineering News named the mini factory in their list of notable chemistry research advances from 2016. [16]
Cell Squeeze is the commercial name for a method for deforming a cell as it passes through a small opening, disrupting the cell membrane and allowing material to be inserted into the cell. [17] [18] It is an alternative method to electroporation or cell-penetrating peptides and operates similarly to a french cell press that temporarily disrupts cells, rather than completely bursting them. [19]
The cell-disrupting change in pressure is achieved by passing cells through a narrow opening in a microfluidic device. The device is made up of channels etched into a wafer through which cells initially flow freely. As they move through the device, the channel width gradually narrows. The cell's flexible membrane allows it to change shape and become thinner and longer, allowing it to squeeze through. As the cell becomes more and more narrow, it shrinks in width by about 30 to 80 percent [18] its original size and the forced rapid change in cell shape temporarily creates holes in the membrane, without damaging or killing the cell.
While the cell membrane is disrupted, target molecules that pass by can enter the cell through the holes in the membrane. As the cell returns to its normal shape, the holes in the membrane close. Virtually any type of molecule can be delivered into any type of cell. [20] The throughput is approximately one million per second. Mechanical disruption methods can cause fewer gene expression changes than electrical or chemical methods. [19] This can be preferable in studies that require the gene expression to be controlled at all times. [21]
Like other cell permeablisation techniques, it enables intracellular delivery materials, such as proteins, siRNA, or carbon nanotubes. The technique has been used for over 20 cell types, including embryonic stem cells and naïve immune cells. [22] Initial applications focused on immune cells, for example delivering:
The process was originally developed in 2013 by Armon Sharei and Andrea Adamo, in the lab of Langer and Jensen at Massachusetts Institute of Technology. [18] In 2014 Sharei founded SQZBiotech to demonstrate the technology. [25] That year, SQZBiotech won the $100,000 grand prize in the annual startup competition sponsored by Boston-based accelerator MassChallenge. [26]
Boeing and the Center for the Advancement of Science in Space (CASIS) awarded the company the CASIS-Boeing Prize for Technology in Space to support the use of Cell Squeeze on the International Space Station (ISS). [27]
Jensen was the recipient of a Guggenheim Fellowship in 1987. [2] [4] [5] [28] Jensen became an Elected Fellow of the Royal Society of Chemistry in 2004 and American Association for the Advancement of Science in 2007. [2] [4] [29] [30] [31] [32] He also became a member of the National Academy of Engineering in 2002 and the American Academy of Arts and Sciences in 2008. [2] [4] [5] In May 2017, he was elected to the National Academy of Sciences in recognition of his "distinguished and continuing achievements in original research." [5] [7]
In 2008, Jensen was included as one of the "100 Chemical Engineers of the Modern Era" by the American Institute of Chemical Engineers' (AIChE) Centennial Celebration Committee. [2] [33] [34] [35] In March 2012, he was the first recipient of the IUPAC-ThalesNano Prize in Flow Chemistry. [2] [12] [35] Jensen was named in Foreign Policy magazine's 2016 list of the leading global thinkers along with Timothy F. Jamison and Allan Myerson. [36] In 2016, he received the AIChE Founders Award for Outstanding Contributions to the Field of Chemical Engineering. [37] [38] Jensen has also received the National Science Foundation Presidential Young Investigator Award. [4] [5]
Klavs Jensen has authored numerous journal articles describing significant advances in flow chemistry, microfluidics, chemical vapor deposition, and chemical engineering which includes but is not limited to:
Microfluidics refers to a system that manipulates a small amount of fluids using small channels with sizes ten to hundreds micrometres. It is a multidisciplinary field that involves molecular analysis, molecular biology, and microelectronics. It has practical applications in the design of systems that process low volumes of fluids to achieve multiplexing, automation, and high-throughput screening. Microfluidics emerged in the beginning of the 1980s and is used in the development of inkjet printheads, DNA chips, lab-on-a-chip technology, micro-propulsion, and micro-thermal technologies.
Semipermeable membrane is a type of synthetic or biologic, polymeric membrane that allows certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. How the membrane is constructed to be selective in its permeability will determine the rate and the permeability. Many natural and synthetic materials which are rather thick are also semipermeable. One example of this is the thin film on the inside of an egg.
Quantum dots (QDs) or semiconductor nanocrystals are semiconductor particles a few nanometres in size with optical and electronic properties that differ from those of larger particles via quantum mechanical effects. They are a central topic in nanotechnology and materials science. When a quantum dot is illuminated by UV light, an electron in the quantum dot can be excited to a state of higher energy. In the case of a semiconducting quantum dot, this process corresponds to the transition of an electron from the valence band to the conductance band. The excited electron can drop back into the valence band releasing its energy as light. This light emission (photoluminescence) is illustrated in the figure on the right. The color of that light depends on the energy difference between the conductance band and the valence band, or the transition between discrete energy states when the band structure is no longer well-defined in QDs.
Chemical biology is a scientific discipline between the fields of chemistry and biology. The discipline involves the application of chemical techniques, analysis, and often small molecules produced through synthetic chemistry, to the study and manipulation of biological systems. Although often confused with biochemistry, which studies the chemistry of biomolecules and regulation of biochemical pathways within and between cells, chemical biology remains distinct by focusing on the application of chemical tools to address biological questions.
Robert Samuel Langer Jr. FREng is an American biotechnologist, businessman, chemical engineer, chemist, and inventor. He is one of the nine Institute Professors at the Massachusetts Institute of Technology.
This is an alphabetical list of articles pertaining specifically to chemical engineering.
Exogenous DNA is DNA originating outside the organism of concern or study. Exogenous DNA can be found naturally in the form of partially degraded fragments left over from dead cells. These DNA fragments may then become integrated into the chromosomes of nearby bacterial cells to undergo mutagenesis. This process of altering bacteria is known as transformation. Bacteria may also undergo artificial transformation through chemical and biological processes. The introduction of exogenous DNA into eukaryotic cells is known as transfection. Exogenous DNA can also be artificially inserted into the genome, which revolutionized the process of genetic modification in animals. By microinjecting an artificial transgene into the nucleus of an animal embryo, the exogenous DNA is allowed to merge the cell's existing DNA to create a genetically modified, transgenic animal. The creation of transgenic animals also leads into the study of altering sperm cells with exogenous DNA.
George McClelland Whitesides is an American chemist and professor of chemistry at Harvard University. He is best known for his work in the areas of nuclear magnetic resonance spectroscopy, organometallic chemistry, molecular self-assembly, soft lithography, microfabrication, microfluidics, and nanotechnology. A prolific author and patent holder who has received many awards, he received the highest Hirsch index rating of all living chemists in 2011.
Cell-penetrating peptides (CPPs) are short peptides that facilitate cellular intake and uptake of molecules ranging from nanosize particles to small chemical compounds to large fragments of DNA. The "cargo" is associated with the peptides either through chemical linkage via covalent bonds or through non-covalent interactions.
Bio-MEMS is an abbreviation for biomedical microelectromechanical systems. Bio-MEMS have considerable overlap, and is sometimes considered synonymous, with lab-on-a-chip (LOC) and micro total analysis systems (μTAS). Bio-MEMS is typically more focused on mechanical parts and microfabrication technologies made suitable for biological applications. On the other hand, lab-on-a-chip is concerned with miniaturization and integration of laboratory processes and experiments into single chips. In this definition, lab-on-a-chip devices do not strictly have biological applications, although most do or are amenable to be adapted for biological purposes. Similarly, micro total analysis systems may not have biological applications in mind, and are usually dedicated to chemical analysis. A broad definition for bio-MEMS can be used to refer to the science and technology of operating at the microscale for biological and biomedical applications, which may or may not include any electronic or mechanical functions. The interdisciplinary nature of bio-MEMS combines material sciences, clinical sciences, medicine, surgery, electrical engineering, mechanical engineering, optical engineering, chemical engineering, and biomedical engineering. Some of its major applications include genomics, proteomics, molecular diagnostics, point-of-care diagnostics, tissue engineering, single cell analysis and implantable microdevices.
Stephen James Lippard is the Arthur Amos Noyes Emeritus Professor of Chemistry at the Massachusetts Institute of Technology. He is considered one of the founders of bioinorganic chemistry, studying the interactions of nonliving substances such as metals with biological systems. He is also considered a founder of metalloneurochemistry, the study of metal ions and their effects in the brain and nervous system. He has done pioneering work in understanding protein structure and synthesis, the enzymatic functions of methane monooxygenase (MMO), and the mechanisms of cisplatin anticancer drugs. His work has applications for the treatment of cancer, for bioremediation of the environment, and for the development of synthetic methanol-based fuels.
Core–shell semiconducting nanocrystals (CSSNCs) are a class of materials which have properties intermediate between those of small, individual molecules and those of bulk, crystalline semiconductors. They are unique because of their easily modular properties, which are a result of their size. These nanocrystals are composed of a quantum dot semiconducting core material and a shell of a distinct semiconducting material. The core and the shell are typically composed of type II–VI, IV–VI, and III–V semiconductors, with configurations such as CdS/ZnS, CdSe/ZnS, CdSe/CdS, and InAs/CdSe Organically passivated quantum dots have low fluorescence quantum yield due to surface related trap states. CSSNCs address this problem because the shell increases quantum yield by passivating the surface trap states. In addition, the shell provides protection against environmental changes, photo-oxidative degradation, and provides another route for modularity. Precise control of the size, shape, and composition of both the core and the shell enable the emission wavelength to be tuned over a wider range of wavelengths than with either individual semiconductor. These materials have found applications in biological systems and optics.
An organ-on-a-chip (OOC) is a multi-channel 3-D microfluidic cell culture, integrated circuit (chip) that simulates the activities, mechanics and physiological response of an entire organ or an organ system. It constitutes the subject matter of significant biomedical engineering research, more precisely in bio-MEMS. The convergence of labs-on-chips (LOCs) and cell biology has permitted the study of human physiology in an organ-specific context. By acting as a more sophisticated in vitro approximation of complex tissues than standard cell culture, they provide the potential as an alternative to animal models for drug development and toxin testing.
Moungi Bawendi is an American–Tunisian–French chemist. He is currently the Lester Wolfe Professor at the Massachusetts Institute of Technology. Bawendi is known for his advances in the chemical production of high-quality quantum dots. For this work, he was awarded the Nobel Prize in Chemistry in 2023.
Droplet-based microfluidics manipulate discrete volumes of fluids in immiscible phases with low Reynolds number and laminar flow regimes. Interest in droplet-based microfluidics systems has been growing substantially in past decades. Microdroplets offer the feasibility of handling miniature volumes of fluids conveniently, provide better mixing, encapsulation, sorting, sensing and are suitable for high throughput experiments. Two immiscible phases used for the droplet based systems are referred to as the continuous phase and dispersed phase.
Bradley Lether Pentelute is currently a professor of chemistry at the Massachusetts Institute of Technology (MIT). His research program lies at the intersection of chemistry and biology and develops bioconjugation strategies, cytosolic delivery platforms, and rapid flow synthesis technologies to optimize the production, achieve site-specific modification, enhance stability, and modulate function of a variety of bioactive agents. His laboratory successfully modified proteins via cysteine-containing “pi-clamps” made up of a short sequence of amino acids, and delivered large biomolecules, such as various proteins and drugs, into cells via the anthrax delivery vehicle. Pentelute has also made several key contributions to automated synthesis technologies in flow. These advances includes the invention of the world's fastest polypeptide synthesizer. This system is able to form amide bonds at a more efficient rate than standard commercial equipment and has helped in the process of understanding protein folding and its mechanisms. This automated flow technology was recently used to achieve total chemical synthesis of protein chains up to 164 amino acids in length that retained the structure and function of native variants obtained by recombinant expression. The primary goal of his endeavor is to use these processes to create designer biologics that can be used to treat diseases and solve the manufacturing problem for on-demand personalized therapies, such as cancer vaccines.
1,4-Dicyanobenzene is an organic compound with the formula C6H4(CN)2. Two other isomers exist, phthalonitrile and isophthalonitrile. All three isomers are produced commercially by ammoxidation of the corresponding xylene isomers. 1,4-Dicyanobenzene is a colorless or white solid with low solubility in water. Hydrogenation of isophthalonitrile affords p-xylylenediamine.
Amol Arvindrao Kulkarni is an Indian research scientist at National Chemical Laboratory, Pune. He earned his PhD from the Institute of Chemical Technology, Mumbai in chemical engineering. His research expertise includes design and development of microreactors.
Intracellular delivery is the process of introducing external materials into living cells. Materials that are delivered into cells include nucleic acids, proteins, peptides, impermeable small molecules, synthetic nanomaterials, organelles, and micron-scale tracers, devices and objects. Such molecules and materials can be used to investigate cellular behavior, engineer cell operations or correct a pathological function.
Christopher Bruce Murray is the Richard Perry University Professor of Chemistry and Materials Science and Engineering at the University of Pennsylvania. He is a member of the National Academy of Engineering and a Fellow of the Materials Research Society. He was a Clarivate Citation Laureate in 2020. He is known for his contributions to quantum dots and other nanoscale materials.