Engineered Cancer Targeting Microbes and Encapsulation Devices for Human Gut Microbiome Applications

Enhancing the persistence of engineered biotherapeutics in the gut: Adhesion, glycan metabolism, and environmental resistance

Engineered live biotherapeutic products (eLBPs) are receiving increasing attention as next-generation therapeutics to treat a variety of diseases with high specificity and effectiveness. Despite their potential, eLBPs face challenges, such as limited colonization, competition with native microbiota, nutrient depletion, and susceptibility to gastrointestinal stresses, which ultimately reduce their persistence in the gut and hinder their therapeutic efficacy. This review examines the key strategies to enhance the persistence and activity of eLBPs in the gut environment. First, methods to strengthen the adhesion capacity of eLBPs are discussed, including genetic engineering to express adhesins and chemical surface modifications to improve their binding to mucus and epithelial cells. Second, strategies to improve the ability of eLBPs to efficiently use mucin-derived sugars, which are continuously secreted by intestinal epithelial cells, were highlighted. These strategies involve the introduction and optimization of glycan-degrading enzymes and metabolic pathways for key mucin sugars, such as N-acetylglucosamine, galactose, and sialic acid, to support sustained energy production and enhance gut colonization. Third, strategies to improve the resistance of eLBPs against environmental stress are discussed, including genetic modifications to stabilize cell membranes, enhancement of ion pump activity, overexpression of stress-response proteins, and encapsulation techniques to provide protection. The implementation of these strategies can address challenges related to gut colonization by eLBPs, thereby enhancing their metabolic activity and enabling sustained and efficient secretion of therapeutic molecules. This review offers a comprehensive framework for developing and optimizing eLBPs, paving the way for their successful clinical application with enhanced effectiveness in treating gastrointestinal and systemic diseases.

Gut microbiota in colorectal cancer: a review of its influence on tumor immune surveillance and therapeutic response

Colorectal cancer (CRC) poses a significant global health burden, with gut microbiota emerging as a crucial modulator of CRC pathogenesis and therapeutic outcomes. This review synthesizes current evidence on the influence of gut microbiota on tumor immune surveillance and responses to immunotherapies and chemotherapy in CRC. We highlight the role of specific microbial taxa in promoting or inhibiting tumor growth and the potential of microbiota-based biomarkers for predicting treatment efficacy. The review also discusses the implications of microbiota modulation strategies, including diet, probiotics, and fecal microbiota transplantation, for personalized CRC management. By critically evaluating the literature, we aim to provide a comprehensive understanding of the gut microbiota's dual role in CRC and to inform future research directions in this field.

Engineering bacterial theranostics: from logic gates to in vivo applications

Over the past 2 decades, rapid advances in synthetic biology have enabled the design of increasingly intricate and biologically relevant systems with broad applications in healthcare. A growing area of interest is in designing bacteria that sense and respond to endogenous disease-associated signals, creating engineered theranostics that function as disease surveyors for human health. In particular, engineered cells hold potential in facilitating greatly enhanced temporal and spatial control over the release of a range of therapeutics. Such systems are particularly useful for targeting challenging, under-drugged disease targets in a more nuanced manner than is currently possible. This review provides an overview of the recent advances in the design, delivery, and dynamics of bacterial theranostics to enable safe, robust, and genetically tractable therapies to treat disease. It outlines the primary challenges in theranostic clinical translation, proposes strategies to overcome these issues, and explores promising future avenues for the field.

From competition to cure: the development of live biotherapeutic products for anticancer therapy in the iGEM competition

Cancer is a leading cause of mortality globally, often diagnosed at advanced stages with metastases already present, complicating treatment efficacy. Traditional treatments like chemotherapy and radiotherapy face challenges such as lack of specificity and drug resistance. The hallmarks of cancer, as defined by Hanahan and Weinberg, describe tumors as complex entities capable of evolving traits that promote malignancy, including sustained proliferation, resistance to cell death, and metastasis. Emerging research highlights the significant role of the microbiome in cancer development and treatment, influencing tumor progression and immune responses. This review explores the potential of live biotherapeutic products (LBPs) for cancer diagnosis and therapy, focusing on projects from the International Genetically Engineered Machines (iGEM) competition that aim to innovate LBPs for cancer treatment. Analyzing 77 projects from 2022, we highlight the progress and ongoing challenges within this research field.

Engineered microorganisms: A new direction in kidney stone prevention and treatment

Numerous studies have shown that intestinal and urinary tract flora are closely related to the formation of kidney stones. The removal of probiotics represented by lactic acid bacteria and the colonization of pathogenic bacteria can directly or indirectly promote the occurrence of kidney stones. However, currently existing natural probiotics have limitations. Synthetic biology is an emerging discipline in which cells or living organisms are genetically designed and modified to have biological functions that meet human needs, or even create new biological systems, and has now become a research hotspot in various fields. Using synthetic biology approaches of microbial engineering and biological redesign to enable probiotic bacteria to acquire new phenotypes or heterologous protein expression capabilities is an important part of synthetic biology research. Synthetic biology modification of microorganisms in the gut and urinary tract can effectively inhibit the development of kidney stones by a range of means, including direct degradation of metabolites that promote stone production or indirect regulation of flora homeostasis. This article reviews the research status of engineered microorganisms in the prevention and treatment of kidney stones, to provide a new and effective idea for the prevention and treatment of kidney stones.

Cell-Free Protein Expression in Polymer Materials

While synthetic biology has advanced complex capabilities such as sensing and molecular synthesis in aqueous solutions, important applications may also be pursued for biological systems in solid materials. Harsh processing conditions used to produce many synthetic materials such as plastics make the incorporation of biological functionality challenging. One technology that shows promise in circumventing these issues is cell-free protein synthesis (CFPS), where core cellular functionality is reconstituted outside the cell. CFPS enables genetic functions to be implemented without the complications of membrane transport or concerns over the cellular viability or release of genetically modified organisms. Here, we demonstrate that dried CFPS reactions have remarkable tolerance to heat and organic solvent exposure during the casting processes for polymer materials. We demonstrate the utility of this observation by creating plastics that have spatially patterned genetic functionality, produce antimicrobials in situ, and perform sensing reactions. The resulting materials unlock the potential to deliver DNA-programmable biofunctionality in a ubiquitous class of synthetic materials.

Targeting microbiome, drug metabolism, and drug delivery in oncology

Recent emerging scientific evidence shows a relationship between gut microbiota (GM) and immunomodulation. In the recently published "Hallmarks of Cancer", the microbiome has been reported to play a crucial role in cancer research, and perspectives for its clinical implementation to improve the effectiveness of pharmacotherapy were explored. Several studies have shown that GM can affect the outcomes of pharmacotherapy in cancer, suggesting that GM may affect anti-tumor immunity. Thus, studies on GM that analyze big data using computer-based analytical methods are required. In order to successfully deliver GM to an environment conducive to the proliferation of immune cells both within and outside the tumor microenvironment (TME), it is crucial to address a variety of challenges associated with distinct delivery methods, specifically those pertaining to oral, endoscopic, and intravenous delivery. Clinical trials are in progress to evaluate the effects of targeting GM and whether it can enhance immunity or act on the TME, thereby to improve the clinical outcomes for cancer patients.