Fabrication of Biomolecule-Covalent-Organic-Framework Composites as Responsive Platforms for Smart Regulation of Fermentation Application

Covalent organic frameworks as superior adsorbents for the removal of toxic substances

Developing new materials capable of the safe and efficient removal of toxic substances has become a research hotspot in the field of materials science, as these toxic substances pose a serious threat to human health, both directly and indirectly. Covalent organic frameworks (COFs), as an emerging class of crystalline porous materials, have advantages such as large specific surface area, tunable pore size, designable structure, and good biocompatibility, which have been proven to be a superior adsorbent design platform for toxic substances capture. This review will summarize the synthesis methods of COFs and the properties and characteristics of typical toxicants, discuss the design strategies of COF-based adsorbents for the removal of toxic substances, and highlight the recent advancements in COF-based adsorbents as robust candidates for the efficient removal of various types of toxicants, such as animal toxins, microbial toxins, phytotoxins, environmental toxins, etc. The adsorption performance and related mechanisms of COF-based adsorbents for different types of toxic substances will be discussed. The complex host-guest interactions mainly include electrostatic, π-π interactions, hydrogen bonding, hydrophobic interactions, and molecular sieving effects. In addition, the adsorption performance of various COF-based adsorbents will be compared, and strategies such as reasonable adjustment of pore size, introduction of functionalities, and preparation of composite materials can effectively improve the adsorption efficiency of toxins. Finally, we also point out the challenges and future development directions that COFs may face in the field of toxicant removal. It is expected that this review will provide valuable insights into the application of COF-based adsorbents in the removal of toxicants and the development of new materials.

Biomolecules meet organic frameworks: from synthesis strategies to diverse applications

Biomolecules are essential in pharmaceuticals, biocatalysts, biomaterials, etc., but unfortunately they are extremely susceptible to extraneous conditions. When biomolecules meet porous organic frameworks, significantly improved thermal, chemical, and mechanical stabilities are not only acquired for raw biomolecules, but also molecule sieving, substrate enrichment, chirality property, and other functionalities are additionally introduced for application expansions. In addition, the intriguing synergistic effect stemming from elaborate and concerted interactions between biomolecules and frameworks can further enhance application performances. In this paper, the synthesis strategies of the so-called bio-organic frameworks (BOFs) in recent years are systematically reviewed and classified. Additionally, their broad applications in biomedicine, catalysis, separation, sensing, and imaging are introduced and discussed. Before ending, the current challenges and prospects in the future for this infancy-stage but significant research field are also provided. We hope that this review will offer a concise but comprehensive vision of designing and constructing multifunctional BOF materials as well as their full explorations in various fields.

Integration of Enzyme and Covalent Organic Frameworks: From Rational Design to Applications

Manufacturing is undergoing profound transformations, among which green biomanufacturing with low energy consumption, high efficiency, and sustainability is becoming one of the major trends. However, enzymes, as the "core chip" of biomanufacturing, are often handicapped in their application by their high cost, low operational stability, and nonreusability. Immobilization of enzymes is a technology that binds or restricts enzymes in a certain area with solid materials, allows them to still carry out their unique catalytic reaction, and allows them to be recycled and reused. Compared with free enzymes, immobilized enzymes boast numerous advantages such as enhanced storage stability, ease of separation, reusability, and controlled operation. Currently, commonly used supports for enzyme immobilization (e.g., mesoporous silica, sol-gel hydrogels, and porous polymer) can effectively improve enzyme stability and reduce product inhibition. However, they still face drawbacks such as potential leaching or conformational change during immobilization and poor machining performance. Especially, most enzyme carrier solid materials possess disordered structures, inevitably introducing deficiencies such as low loading capacity, hindered mass transfer, and unclear structure-property relationships. Additionally, it remains a notable challenge to meticulously design immobilization systems tailored to the specific characteristics of enzyme/reaction. Therefore, there is a significant demand for reliable solid materials to overcome the above challenges. Crystalline porous materials, particularly covalent organic frameworks (COFs), have garnered significant interest as a promising platform for immobilizing enzymes due to their unique properties, such as their crystalline nature, high porosity, accessible active sites, versatile synthetic conditions, and tunable structure. COFs create a stabilizing microenvironment that protects enzymes from denaturation and significantly enhances reusability. Nevertheless, some challenges still remain, including difficulties in loading large enzymes, reduced enzyme activities, and the limited functionality of carriers. Therefore, it is essential to develop innovative carriers and novel strategies to broaden the methods of immobilizing enzymes, enabling their application across a more diverse array of fields.The integration of enzymes with advanced porous materials for intensified performance and diverse applications is still in its infancy, and our group has done a series of pioneering works. This Account presents a comprehensive overview of recent research progress made by our group, including (i) the development of innovative enzyme immobilization strategies utilizing COFs to make the assembly and integration of enzymes and carriers more effective; (ii) rational design and construction of functional carriers for enzyme immobilization using COFs; and (iii) extensions of immobilized enzyme applications based on COFs from industrial catalysis to biomedicine and chiral separation. The integration of enzymes with functional crystalline materials offers mutual benefits and results in a performance that surpasses what either component can achieve individually. Additionally, immobilized enzymes exhibit enhanced functionality and intriguing characteristics that differ from those of free enzymes. Consistent with our research philosophy centered on integration, platform development, and engineering application, this Account addresses the critical challenges associated with enzyme immobilization using COFs while extending the applications of COFs and proposing future design principles for biomanufacturing and enzyme industry.

Application of digital-intelligence technology in the processing of Chinese materia medica

Processing of Chinese Materia Medica (PCMM) is the concentrated embodiment, which is the core of Chinese unique traditional pharmaceutical technology. The processing includes the preparation steps such as cleansing, cutting and stir-frying, to make certain impacts on the quality and efficacy of Chinese botanical drugs. The rapid development of new computer digital technologies, such as big data analysis, Internet of Things (IoT), blockchain and cloud computing artificial intelligence, has promoted the rapid development of traditional pharmaceutical manufacturing industry with digitalization and intellectualization. In this review, the application of digital intelligence technology in the PCMM was analyzed and discussed, which hopefully promoted the standardization of the process and secured the quality of botanical drugs decoction pieces. Through the intellectualization and the digitization of production, safety and effectiveness of clinical use of traditional Chinese medicine (TCM) decoction pieces were ensured. This review also provided a theoretical basis for further technical upgrading and high-quality development of TCM industry.

Application of digital-intelligence technology in the processing of Chinese materia medica

Processing of Chinese Materia Medica (PCMM) is the concentrated embodiment, which is the core of Chinese unique traditional pharmaceutical technology. The processing includes the preparation steps such as cleansing, cutting and stir-frying, to make certain impacts on the quality and efficacy of Chinese botanical drugs. The rapid development of new computer digital technologies, such as big data analysis, Internet of Things (IoT), blockchain and cloud computing artificial intelligence, has promoted the rapid development of traditional pharmaceutical manufacturing industry with digitalization and intellectualization. In this review, the application of digital intelligence technology in the PCMM was analyzed and discussed, which hopefully promoted the standardization of the process and secured the quality of botanical drugs decoction pieces. Through the intellectualization and the digitization of production, safety and effectiveness of clinical use of traditional Chinese medicine (TCM) decoction pieces were ensured. This review also provided a theoretical basis for further technical upgrading and high-quality development of TCM industry.

Confining enzymes in porous organic frameworks: from synthetic strategy and characterization to healthcare applications

Enzymes are a class of natural catalysts with high efficiency, specificity, and selectivity unmatched by their synthetic counterparts and dictate a myriad of reactions that constitute various cascades in living cells. The development of suitable supports is significant for the immobilization of structurally flexible enzymes, enabling biomimetic transformation in the extracellular environment. Accordingly, porous organic frameworks, including metal organic frameworks (MOFs), covalent organic frameworks (COFs) and hydrogen-bonded organic frameworks (HOFs), have emerged as ideal supports for the immobilization of enzymes because of their structural features including ultrahigh surface area, tailorable porosity, and versatile framework compositions. Specially, organic framework-encased enzymes have shown significant enhancement in stability and reusability, and their tailorable pore opening provides a gatekeeper-like effect for guest sieving, which is beneficial for mimicking intracellular biocatalysis processes. This immobilization technique brings new insight into the development of next-generation enzyme materials and shows huge potential in healthcare applications, such as biomarker diagnosis, biostorage, and cancer and antibacterial therapies. In this review, we describe the state-of-the-art strategies for the structural immobilization of enzymes using the well-explored MOFs and burgeoning COFs and HOFs as scaffolds, with special emphasis on how these porous framework-confined technologies can provide a favorable microenvironment for mimicking natural biocatalysis. Subsequently, advanced characterization techniques for enzyme conformation, the effect of the confined microenvironment on the activity of enzymes, and the emerging healthcare applications will be surveyed.

Metalated covalent organic frameworks: from synthetic strategies to diverse applications

Covalent organic frameworks (COFs) are a class of organic crystalline porous materials discovered in the early 21st century that have become an attractive class of emerging materials due to their high crystallinity, intrinsic porosity, structural regularity, diverse functionality, design flexibility, and outstanding stability. However, many chemical and physical properties strongly depend on the presence of metal ions in materials for advanced applications, but metal-free COFs do not have these properties and are therefore excluded from such applications. Metalated COFs formed by combining COFs with metal ions, while retaining the advantages of COFs, have additional intriguing properties and applications, and have attracted considerable attention over the past decade. This review presents all aspects of metalated COFs, from synthetic strategies to various applications, in the hope of promoting the continued development of this young field.

New potential of boron-based COFs: the biocompatible COF-1 for reactive oxygen generation and antimicrobial applications

Photocatalytic covalent organic frameworks (COFs) are popular in the field of biomedical materials and also have potential as antimicrobial materials. Herein, a boron-based COF was used in antibacterial applications innovatively. The results of this study suggested that COF-1, the earliest boroxine COF, could produce a variety of reactive oxygen species (ROS) under visible light irradiation. In order to explore more applications of COF-1, antibacterial tests were carried out based on the above results. The test results showed that the material displayed an obvious bactericidal effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by releasing ROS under white light. According to the results of plate coating, all bacteria died after co-cultivation with COF-1 under white light for about 120 minutes. In a word, this study could provide a new idea for the application of boron-based COFs as multifunctional photocatalysts in future.

A double responsive fluorescent platform for sensing heavy metal ions based on a dual-emitting fluorescent covalent organic framework hydrogel film

A new luminescent hybrid material with dual-emission centers (Eu@Dye@TpDq hydrogel) based on covalent organic framework (COF) has been successfully prepared. First, we designed a dye (coumarin) modified COF (TpDq) hybrid...