3D microfabrication of biological machines

The burgeoning field of additive manufacturing, or “3D printing”, centers on the idea of creating three-dimensional objects from digital models. While conventional manufacturing approaches rely on modifying a base material via subtractive processes such as drilling or cutting, 3D printing creates three-dimensional objects through successive deposition of two- dimensional layers. By enabling rapid fabrication of complex objects, 3D printing is revolutionizing the fields of engineering design and manufacturing. This thesis details the development of a projection-based stereolithographic 3D printing apparatus capable of high- resolution patterning of living cells and cell signals dispersed in an absorbent hydrogel polymer matrix in vitro. This novel enabling technology can be used to create model cellular systems that lead to a quantitative understanding of the way cells sense, process, and respond to signals in their environment. The ability to pattern cells and instructive biomaterials into complex 3D patterns has many applications in the field of tissue engineering, or “reverse engineering” of cellular systems that replicate the structure and function of native tissue. While the goal of reverse engineering native tissue is promising for medical applications, this idea of building with biological components concurrently brings about a new discipline: “forward engineering” of biological machines and systems. In addition to rebuilding existing systems with cells, this technology enables the design and forward engineering of novel systems that harness the innate dynamic abilities of cells to self-organize, self-heal, and self-replicate in response to environmental cues. This thesis details the development of skeletal and cardiac muscle based bioactuators that can sense external electrical and optical signals and demonstrate controlled locomotive behavior in response to them. Such machines, which can sense, process, and respond to signals in a dynamic environment, have a myriad array of applications including toxin neutralization and high throughput drug testing in vitro and drug delivery and programmable tissue engineered implants in vivo. A synthesis of two fields, 3D printing and tissue engineering, has brought about a new discipline: using microfabrication technologies to forward engineer biological machines and systems capable of complex functional behavior. By introducing a new set of “building blocks” into the engineer’s toolbox, this new era of design and manufacturing promises to open up a field of research that will redefine our world

3D printed muscle-powered bio-bots

Complex biological systems sense, process, and respond to a range of environmental signals in real-time. The ability of such systems to adapt their functional response to dynamic external signals motivates the use of biological materials in other engineering applications. Recent advances in 3D printing have enabled the manufacture of complex structures from biological materials. We have developed a projection stereolithographic 3D printing apparatus capable of patterning cells and biocompatible polymers at physiologically relevant length scales, on the order of single cells. This enables reverse engineering in vitro model systems that recreate the structure and function of native tissue for applications ranging from high-throughput drug testing to regenerative medicine. While reverse engineering native tissues and organs has important implications in biomedical engineering, the ability to “build with biology” presents the next generation of engineers with both a unique design challenge and opportunity. Specifically, we now have the ability to forward engineer bio-hybrid machines and robots (bio-bots) that harness the adaptive functionalities of biological materials to achieve more complex functional behaviors than machines composed of synthetic materials alone. Perhaps the most intuitive demonstration of a “living machine” is a system that can generate force and produce motion. To that end, we have designed and 3D printed locomotive bio-bots, powered by external electrical and optical stimuli. In addition to being the first demonstrations of untethered locomotion in skeletal musclepowered soft robots, these bio-hybrid machines have served as meso-scale models for studying tissue self-assembly, maturation, damage, remodeling, and healing in vitro. Bio-hybrid machines that can dynamically sense and adaptively respond to a range of environmental signals have broad applicability in healthcare applications such as dynamic implants or targeted drug delivery. Advanced research in exoskeletons and hyper-natural functionality could even extend the useful application of such machines to national defense and environmental cleanup. We have developed a modular skeletal muscle bioactuator that can serve as a fundamental building block for such machines, setting the stage for future generations of bio-hybrid machines that can self-assemble, self-heal, and perhaps even self-replicate to target grand engineering challenges. Furthermore, we present a robust optimized protocol for manufacturing 3D printed muscle-powered biological machines, and a mechanism to incorporate biological “building blocks” into the toolbox of the next generation of engineers and scientists

GA3 mediated enhanced transcriptional rate and mRNA stability of 3-hydroxy-3-methylglutaryl coenzyme a reductase 1 (NtHMGR1) in Nicotiana tabacum L.

Our present study evaluated the underlying molecular-mechanism(s) associated with the observed enhanced transcript levels and concomitant functional activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase 1 (NtHMGR1), a rate-limiting enzyme of cytosolic mevalonate (MVA) pathway of terpenoids biosynthesis, by gibberellin A3 (GA3) treatment in model cultivated tobacco, Nicotiana tabacum L. Based on the transcription run-on and cordycepin chase assays, our results demonstrated that tobacco seeds-priming with GA3 causes a relative and significantly enhanced transcriptional rate and mRNA stability of NtHMGR1. Taken together, our study established that GA3 mediated transcriptional and post-transcriptional regulatory control as one of the mechanisms for the observed enhanced transcript-levels and consequently enhanced functional activity of NtHMGR1

Laryngeal Paraganglioma with Chronic Cough: A Case Report

Laryngeal paragangliomas are rare lesions originating from paraganglion cells within the supraglottis or subglottis. As per the latest review, only 76 such cases have been reported in the literature. Symptoms typically include dysphonia or dysphagia. We present, to the best of our knowledge, the first known case of laryngeal paraganglioma with chronic cough as the primary complaint. A 77-year-old male presented with chronic cough. Flexible laryngoscopy revealed a supraglottic submucosal mass emanating from the region of the right false vocal cord and aryepiglottic fold. Postcontrast computed tomography scan showed a well-defined intensely enhancing mass arising from the right paraglottic space and bulging into the right pyriform sinus. Biopsies and immunohistochemical markers supported the diagnosis of paraganglioma. A complete submucosal excision of the mass via a right transcervical approach with tracheostomy was performed. Postoperatively, the patient’s cough resolved. Laryngeal paragangliomas are rare tumors that are known to present with dysphonia or dysphagia. This is the first case report of a patient presenting with chronic cough as the primary complaint

Principles for the design of multicellular engineered living systems

Remarkable progress in bioengineering over the past two decades has enabled the formulation of fundamental design principles for a variety of medical and non-medical applications. These advancements have laid the foundation for building multicellular engineered living systems (M-CELS) from biological parts, forming functional modules integrated into living machines. These cognizant design principles for living systems encompass novel genetic circuit manipulation, self-assembly, cell–cell/matrix communication, and artificial tissues/organs enabled through systems biology, bioinformatics, computational biology, genetic engineering, and microfluidics. Here, we introduce design principles and a blueprint for forward production of robust and standardized M-CELS, which may undergo variable reiterations through the classic design-build-test-debug cycle. This Review provides practical and theoretical frameworks to forward-design, control, and optimize novel M-CELS. Potential applications include biopharmaceuticals, bioreactor factories, biofuels, environmental bioremediation, cellular computing, biohybrid digital technology, and experimental investigations into mechanisms of multicellular organisms normally hidden inside the “black box” of living cells

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Engineered neuromuscular actuators for medicine, meat, and machines

Abstract Movement is central to life. Neuromuscular tissues control voluntary movement in humans and many other living creatures, offering significant advantages in adaptability and robustness as compared to abiotic actuators. The impressive functional capabilities of neuromuscular tissues have inspired researchers to attempt de novo synthesis of the biological motor system via tissue engineering. This article highlights key recent advances in tissue engineering skeletal muscle and discusses promising strategies to control engineered muscle via biological neural networks and abiotic soft electronic interfaces. Challenges associated with cell sourcing, biomaterials design, and scalable precision manufacturing, along with emerging strategies to address those challenges, are presented. Finally, we highlight how engineered neuromuscular tissues have enabled studying, controlling, and deploying them as actuators in a range of real-world applications including drug discovery, regenerative medicine, cellular agriculture, and soft robotics. Graphic abstrac

3D Printing Smart Bandages

3D printing has revolutionized engineering design and manufacturing in recent years by enabling the rapid fabrication of complex 3D structures. In stereolithography, a subtype of 3D printing, photosensitive liquid polymers are patterned into solid structures through exposure to ultraviolet (UV) light. Recently, this approach has been optimized for printing living cells dispersed in biocompatible polymers, extending the possible applications of this technology to the realm of biomedical engineering. Shown here is a stereolithographic apparatus (microSLA) that works like a projector in reverse any grayscale image produced on a computer screen can be miniaturized and printed on the micro-scale using UV light. With the microSLA, we have patterned living cells at very high resolution (< 5 'm), providing a high-throughput way to manufacture living tissue and organ mimics from the bottom up. For example, we have printed a smart bandage containing living cells which, when placed on tissue that has been damaged by disease or trauma (such as a heart attack), can regenerate blood vessel growth in the area. This novel 3D printer could in future be used for a wide variety of applications, including drug testing, studies of disease development, and regenerative medicine.Ope

3D microfabrication of biological machines

The burgeoning field of additive manufacturing, or “3D printing”, centers on the idea of creating three-dimensional objects from digital models. While conventional manufacturing approaches rely on modifying a base material via subtractive processes such as drilling or cutting, 3D printing creates three-dimensional objects through successive deposition of two- dimensional layers. By enabling rapid fabrication of complex objects, 3D printing is revolutionizing the fields of engineering design and manufacturing. This thesis details the development of a projection-based stereolithographic 3D printing apparatus capable of high- resolution patterning of living cells and cell signals dispersed in an absorbent hydrogel polymer matrix in vitro. This novel enabling technology can be used to create model cellular systems that lead to a quantitative understanding of the way cells sense, process, and respond to signals in their environment. The ability to pattern cells and instructive biomaterials into complex 3D patterns has many applications in the field of tissue engineering, or “reverse engineering” of cellular systems that replicate the structure and function of native tissue. While the goal of reverse engineering native tissue is promising for medical applications, this idea of building with biological components concurrently brings about a new discipline: “forward engineering” of biological machines and systems. In addition to rebuilding existing systems with cells, this technology enables the design and forward engineering of novel systems that harness the innate dynamic abilities of cells to self-organize, self-heal, and self-replicate in response to environmental cues. This thesis details the development of skeletal and cardiac muscle based bioactuators that can sense external electrical and optical signals and demonstrate controlled locomotive behavior in response to them. Such machines, which can sense, process, and respond to signals in a dynamic environment, have a myriad array of applications including toxin neutralization and high throughput drug testing in vitro and drug delivery and programmable tissue engineered implants in vivo. A synthesis of two fields, 3D printing and tissue engineering, has brought about a new discipline: using microfabrication technologies to forward engineer biological machines and systems capable of complex functional behavior. By introducing a new set of “building blocks” into the engineer’s toolbox, this new era of design and manufacturing promises to open up a field of research that will redefine our world.LimitedAuthor requested closed access (OA after 2yrs) in Vireo ETD syste