Versatile Biomolecules Research Articles

Revisiting microbial exopolysaccharides: a biocompatible and sustainable polymeric material for multifaceted biomedical applications.

Microbial exopolysaccharides (EPS) have gained significant attention as versatile biomolecules with multifarious applications across various sectors. This review explores the valorisation of EPS and its potential impact on diverse sectors, including food, pharmaceuticals, cosmetics, and biotechnology. EPS, secreted by microorganisms, possess unique physicochemical properties, such as high molecular weight, water solubility, and biocompatibility, making them attractive for numerous functional roles. Additionally, EPS exhibit significant bioactivity, contributing to their potential use in pharmaceuticals for drug delivery and tissue engineering applications. Moreover, the eco-friendly and sustainable nature of microbial EPS production aligns with the growing demand for environmentally conscious processes. However, challenges still exist in large-scale production, purification, and regulatory approval for commercial use. Advances in bioprocessing and microbial engineering offer promising solutions to overcome these hurdles. Stringent investigations have concluded EPS as novel sources for sustainable applications that are likely to emerge and develop, further reinforcing the significance of these biopolymers in addressing contemporary societal needs and driving innovation in various industrial sectors. Overall, the microbial EPS represents a thriving field with immense potential for meeting diverse industrial demands and advancing sustainable technologies.

A nano-platform harnessing synergistic amino acid browning for biomedical applications.

Amino acids show promise as versatile biomolecules for creating a variety of functional biomaterials. Previously, we discovered a novel amino acid reaction, in which a single amino acid can form browning species in a simple solvent mixture comprising DMSO and acetone at room temperature. In the present study, we initially conducted a comprehensive analysis of 190 pairs of binary amino acids (i.e., all the possible pairwise combinations out of 20 amino acids) and identified several surprising combinations that exhibited synergistic browning effects. Particularly, cysteine-lysine and cysteine-arginine pairs exhibited pronounced browning in DMSO/acetone cosolvent solutions. We hypothesize that the coloured species result from the formation of extended, hydrophobic molecules with highly conjugated systems, arising from extensive condensation reactions between amino acids. Subsequently, we aimed at developing a nano-platform based on this newly discovered amino acid reaction. We demonstrate that through a nanoprecipitation process (solvent-shifting), spherical nanoparticles with sizes ranging from 100 to 200 nm can be produced, in the presence of ferric ions added to the water phase. Through systematic optimization and comprehensive characterization, the final product is a zwitterionic, charge-reversible nanoparticle featuring three functional groups on its surface: carboxylates, amines, and thiols. Furthermore, it possesses mild antioxidant activity, making it a new type of nano-antioxidant. Finally, we present preliminary results highlighting the potential of using this new nanomaterial as a delivery system for polynucleotides. In conclusion, the paper introduces a novel class of amino acid-derived nanoparticles with significant promise for future biomedical applications.

Versatile Protein and Its Subunit Biomolecules for Advanced Rechargeable Batteries.

Rechargeable batteries are of great significance for alleviating the growing energy crisis by providing efficient and sustainable energy storage solutions. However, the multiple issues associated with the diverse components in a battery system as well as the interphase problems greatly hinder their applications. Proteins and their subunits, peptides, and amino acids, are versatile biomolecules. Functional groups in different amino acids endow these biomolecules with unique properties including self-assembly, ion-conducting, antioxidation, great affinity to exterior species, etc. Besides, protein and its subunit materials can not only work in solid forms but also in liquid forms when dissolved in solutions, making them more versatile to realize materials engineering via diverse approaches. In this review, it is aimed to offer a comprehensive understanding of the properties of proteins and their subunits, and research progress of using these versatile biomolecules to address the engineering issues of various rechargeable batteries, including alkali-ion batteries, lithium-sulfur batteries, metal-air batteries, and flow batteries. The state-of-the-art advances in electrode, electrolyte, separator, binder, catalyst, interphase modification, as well as recycling of rechargeable batteries are involved, and the impacts of biomolecules on electrochemical properties are particularly emphasized. Finally, perspectives on this interesting field are also provided.

Interrelated grid of non-coding RNA: An important aspect in Rheumatoid Arthritis pathogenesis.

Inflammation and autoimmunity are the root cause of rheumatoid arthritis, a destructive disease of joints. Multiple biomolecules are involved in the pathogenesis of RA and are related to various events of molecular biology. RNA is a versatile biomolecule, playing numerous roles at structural, functional, and regulatory stages to maintain cellular homeostasis. The involvement of RNA (coding/non-coding) in disease development and progression has left a wide whole to fill with newer approaches. Non-coding RNAs belong to the housekeeping and regulatory categories and both have their specific roles, and their alteration causes specific implications in disease pathogenesis. Housekeeping RNAs, rRNA, tRNA and regulatory RNA, micro-RNA, circular RNA, piRNA and long non-coding RNA were found to be important regulators of inflammation. They work at the pre-and post-transcriptional levels and were found to be more intriguing to study their regulatory impact on disease pathogenesis. The review addresses a question on how the non-coding RNA gets involved in early RA pathogenesis and can be utilized to know their targets to understand the disease better and make way towards the unresolved mystery of RA development.

Lipoic Acid-Based Poly(disulfide)s as Versatile Biomolecule Delivery Vectors and the Application in Tumor Immunotherapy.

Intracellular delivery of therapeutic biomacromolecules, including nucleic acids and proteins, attracts extensive attention in biotherapeutics for various diseases. Herein, a strategy is proposed for the construction of poly(disulfide)s for the efficient delivery of both nucleic acids and proteins into cells. A convenient photo-cross-linking polymerization was adopted between disulfide bonds in two modified lipoic acid monomers (Zn coordinated with dipicolylamine analogue (ZnDPA) and guanidine (GUA)). The disulfide-containing main chain of the resulting poly(disulfide)s was responsive to reducing circumstance, facilitating the release of cargos. By screening the feeding ratio of ZnDPA and GUA, the resulting poly(disulfide)s exhibited better performance in the delivery of nucleic acids including plasmid DNA and siRNA than commercially available transfection reagents. Cellular uptake results revealed that the polymer/cargo complexes entered the cells mainly following a thiol-mediated uptake pathway. Meanwhile, the polymer could also efficiently deliver proteins into cells without an obvious loss of protein activity, showing the versatility of the poly(disulfide)s for the delivery of various biomacromolecules. Moreover, the in vivo therapeutic effect of the materials was verified in the E.G7-OVA tumor-bearing mice. Ovalbumin-based nanovaccine induced a strong cellular immune response, especially cytotoxic T lymphocyte cellular immune response, and inhibited tumor growth. These results revealed the promise of the poly(disulfide)s in the application of both gene therapy and immunotherapy.

Effects of TiO2 and H2O2 treatments on the biosynthesis of carotenoids and lipids in oleaginous red yeast Rhodotorula glutinis ZHK

Microbial carotenoids and lipids are two groups of versatile biomolecules widely used in the food, fuel, pharmaceutical, and cosmetic industries. Rhodotorula glutinis is one of the best-known oleaginous red yeasts that has the remarkable capability to produce an assortment of valuable carotenoids and lipids. Here, the effects of different concentrations of TiO2 and H2O2 treatments on carotenoid and lipid production in R. glutinis ZHK were investigated. After 120 h of cultivation, the total amount of carotenoids was significantly increased in the TiO2 (100 mg/L: 23.165 μg/gdw, 750 mg/L: 19.65 μg/gdw) and H2O2 (5 mM: 21.51 μg/gdw, 10 mM: 118.858 μg/gdw) treatments than the control (6.099 μg/gdw). In contrast, as compared to the control, the relative abundance of total lipids was significantly decreased in the TiO2 (100 mg/L) and H2O2 (10 mM) treatments, respectively. In response to TiO2 and H2O2 stresses, the increased carotenoids were probably attributed to the down-regulated lipid biosynthesis flux, while the decreased lipids might be ascribed to the down-regulated fatty acid biosynthesis flux. Our results presented herein not only provide an effective strategy for modulating carotenoid and lipid biosynthesis in R. glutinis ZHK but also reveal the molecular foundation to further enhance their bioproductivity by molecular manipulation.

Universal Method for Label-Free Detection of Pathogens and Biomolecules by Surface-Enhanced Raman Spectroscopy Based on Gold Nanoparticles.

The detection of biomolecules is the key to basic molecular research, diagnostics, drug screening, and other biomedical applications. However, the existing detection techniques can only detect single classes of biomolecules, which warrant the development of a versatile biomolecule detection platform. Here, we developed a universal method for label-free detection of biomolecules via surface-enhanced Raman spectroscopy (SERS) by using sulfhydryl-modified gold nanoparticles as the substrate. The biomolecules can be adsorbed on the surface of gold nanoparticles cleaned by bromide ions to obtain initially enhanced Raman signals, and the aggregator (calcium ion) was further added to form a "hot spot", which enhanced the biomolecular signal again. Through the "two-step enhancement method", we were able to obtain fingerprints of DNA, RNA, amino acids, peptides, proteins, viruses, bacteria, and lipid molecules. This low-toxic, highly sensitive, and widely applicable technique has potential applications in biomedical research, clinical testing, and disease diagnosis and lays the foundation for the development of SERS technology in various fields.

Bacterial-derived surfactants: an update on general aspects and forthcoming applications.

The search for sustainable alternatives to the production of chemicals using renewable substrates and natural processes has been widely encouraged. Microbial surfactants or biosurfactants are surface-active compounds synthesized by fungi, yeasts, and bacteria. Due to their great metabolic versatility, bacteria are the most traditional and well-known microbial surfactant producers, being Bacillus and Pseudomonas species their typical representatives. To be successfully applied in industry, surfactants need to maintain stability under the harsh environmental conditions present in manufacturing processes; thus, the prospection of biosurfactants derived from extremophiles is a promising strategy to the discovery of novel and useful molecules. Bacterial surfactants show interesting properties suitable for a range of applications in the oil industry, food, agriculture, pharmaceuticals, cosmetics, bioremediation, and more recently, nanotechnology. In addition, they can be synthesized using renewable resources as substrates, contributing to the circular economy and sustainability. The article presents a general and updated review of bacterial-derived biosurfactants, focusing on the potential of some groups that are still underexploited, as well as, recent trends and contributions of these versatile biomolecules to circular bioeconomy and nanotechnology.

Recent advances in macrophage-derived exosomes as delivery vehicles

Macrophages are important members of the innate immune system that can be reversibly polarized by different microenvironment signals. Exosomes secreted from cells are lipid bilayer membrane vesicles carrying versatile biomolecules, which displays unique properties and biological functions. Recent studies have shown that macrophage derived exosomes as an extracellular vehicle can deliver diverse cargoes including small molecules, nanoparticles, and biological macromolecules to recipient cells, and thus affect the progression of cancers and other diseases. Moreover, exosomes secreted by different phenotypes of macrophages provide different therapeutic options. Thus, in this review, we summarized recent progress in the macrophage derived exosomes as carriers for delivering different types of cargos. Then the engineering principles and their applications are elaborated. In the end, challenges and prospects of macrophage derived exosomes for drug delivery and disease treatment are also discussed.

Ultraviolet photoelectron spectroscopic study on the interface electronic structure of the L‐cysteine on Pd surface

L‐cysteine is one of the most versatile biomolecules with a unique metal‐binding ability. L‐cysteine has an outstanding role in the bioelectronics field as a linker between proteins of biomolecules and metal electrodes of the inorganic metals through multiple functional groups. The interface electronic structures between L‐cysteine with metals deserve further investigation for applications in bioelectronics. However, the interface electronic structures of L‐cysteine and metals have not been well understood. We have previously reported the existence of a new state between the highest occupied molecular orbital (HOMO) of L‐cysteine and the Fermi level of the metals for L‐cysteine/Au(111), L‐cysteine/Ag(111), and L‐cysteine/Cu(111) using photoemission spectroscopy and attributed the formation of the new state to an interaction of the d band with HOMO of L‐cysteine. In this study, the electronic structure at the interfaces of L‐cysteine on a Palladium (Pd) surface is investigated by ultraviolet photoemission spectroscopy (UPS) using synchrotron radiation including work function, secondary electron cutoff (SECO), and HOMO onset; the position of an interface state, charge injection barrier, and ionization energy are estimated. It is observed that thin‐film spectra of L‐cysteine on Pd surfaces in the valance top region are different from the L‐cysteine thick films, and this can be attributed to an interaction between a sulfur‐originated state of L‐cysteine HOMO with Pd d orbitals. Also, a 0.6‐eV SECO shift is estimated due to the charge transferring between L‐cysteine and Pd. The results of SECO further confirm the weakening of the Pd–sulfur bond with increasing L‐cysteine coverage on Pd.

Polymers as Encapsulating Agents and Delivery Vehicles of Enzymes.

Enzymes are versatile biomolecules with broad applications. Since they are biological molecules, they can be easily destabilized when placed in adverse environmental conditions, such as variations in temperature, pH, or ionic strength. In this sense, the use of protective structures, as polymeric capsules, has been an excellent approach to maintain the catalytic stability of enzymes during their application. Thus, in this review, we report the use of polymeric materials as enzyme encapsulation agents, recent technological developments related to this subject, and characterization methodologies and possible applications of the formed bioactive structures. Our search detected that the most explored methods for enzyme encapsulation are ionotropic gelation, spray drying, freeze-drying, nanoprecipitation, and electrospinning. α-chymotrypsin, lysozyme, and β-galactosidase were the most used enzymes in encapsulations, with chitosan and sodium alginate being the main polymers. Furthermore, most studies reported high encapsulation efficiency, enzyme activity maintenance, and stability improvement at pH, temperature, and storage. Therefore, the information presented here shows a direction for the development of encapsulation systems capable of stabilizing different enzymes and obtaining better performance during application.

Chitosan as a Valuable Biomolecule from Seafood Industry Waste in the Design of Green Food Packaging.

Chitosan is a versatile biomolecule with a broad range of applications in food and pharmaceutical products. It can be obtained by the alkaline deacetylation of chitin. This biomolecule can be extracted using conventional or green methods from seafood industry residues, e.g., shrimp shells. Chitin has limited applications because of its low solubility in organic solvents. Chitosan is soluble in acidified solutions allowing its application in the food industry. Furthermore, biological properties, such as antioxidant, antimicrobial, as well as its biodegradability, biocompatibility and nontoxicity have contributed to its increasing application as active food packaging. Nevertheless, some physical and mechanical features have limited a broader range of applications of chitosan-based films. Green approaches may be used to address these limitations, leading to well-designed chitosan-based food packaging, by employing principles of a circular and sustainable economy. In this review, we summarize the properties of chitosan and present a novel green technology as an alternative to conventional chitin extraction and to design environmentally friendly food packaging based on chitosan.

BioEssays 8/2021

BioEssaysVolume 43, Issue 8 2170081 COVER PICTUREFree Access BioEssays 8/2021 First published: 23 July 2021 https://doi.org/10.1002/bies.202170081AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract DNA is a versatile biomolecule that is not only capable of storing the genetic information of a cell, but that can also be used for molecular computing applications. In article 2100051, Sahana Gangadharan and Karthik Raman review how DNA may be used to solve mathematical, logical modeling and network-based problems. The authors also discuss how DNA can be used for data storage and cryptography and briefly touch upon how other biomolecules such as peptides may also be employed for this unconventional type of computing. Volume43, Issue8August 20212170081 RelatedInformation

Characterization and Immunologic Response of IgY Against Leishmania Mexicana

Avian IgYs are polyclonal antibodies resulting from humoral adaptive immune responses. With perspective for many application, IgYs are considered the most versatile biomolecule, able to be used as alternative in biomedicine and as diagnostic tool. Because they are inducible, these antibodies could be produced to potentiate the recognition of relevant clinical pathogens such as Leishmania mexicana. In this investigation anti Leishmania mexicana IgYs were obtained by inoculation of inactivated promastigotes in brown Lohmann hens, at different periods. Twenty-four per cent of the eggs were randomly selected for processing. IgYs were precipitated by Ammonium Sulfate and purified by affinity chromatography. Immunoglobulins with 175 kDa, complete structure, and a concentration of 6.3 mg/mL per yolk were obtained. The most reactive antibodies corresponded to week 8 (W8). These IgYs were tested for specific recognition of their target parasite, using structural and proteins viral as GP63 in Western Blot. Also, they identified concentrations of parasite antigen of 5 and 50 μg/mL with maximal antibody dilution of 1:2000 in ELISA. The IgY-mediated immunodetection offers this as solution to the necessity of anti L. mexicana antibodies for diagnostics and immunotherapy research.

Conjugation Approaches for Peptide-Mediated Delivery of Oligonucleotides Therapeutics

Oligonucleotide-based agents are versatile biomolecules that modulate gene expression. The last decade has seen the emergence of oligonucleotide-based tools for biochemical investigations. Importantly, several oligonucleotide-based drugs and vaccines are currently used for various therapeutic applications ranging from anti-inflammatory and anti-viral agents to those used in cardiovascular, ophthalmic, and neuro-muscular disorders. Despite a broad range of applications, achieving efficient oligonucleotide delivery remains a major limitation. A possible solution is to conjugate cell-penetrating peptides with oligonucleotides. This review provides an overview of chemical strategies used to synthesise peptide–oligonucleotide conjugates. The merits and liabilities of these strategies are discussed in the context of synthetic efficiency, and bio-reversible and -irreversible linkages.

The Abtamer: A Novel Antibody-Aptamer Conjugate for Electrochemical Biosensing Applications

Introduction: We propose an innovated semisynthetic biosensing molecule, the Abtamer, an antibody-aptamer one-to-one complex. An important consideration in the design of electrochemical biosensors is the molecular recognition element (MRE) from which the signal to be transduced is generated. Among MREs utilized for affinity principle based electrochemical biosensors, antibodies are commonly used due to their high sensitivity and selectivity towards specific targets. However, antibodies’ structural rigidity proves limiting in biosensing applications.In contrast, DNA/RNA aptamers are easily-synthesized, versatile biomolecules, which are able to exhibit a high affinity and sensitivity towards their selected target [1]. Owing to their structure, aptamers are inherently flexible which allows for pronounced conformational changes upon binding. Furthermore, their small size allows for the immobilization of a larger density of molecules on the sensor surface, aiding in their sensitivity [2]. However, these same characteristics put aptamers at a disadvantage in terms of their selectivity towards targets. Without various post-synthesis modifications, DNA/RNA oligonucleotides can exhibit nonspecific electrostatic interactions with other analytes in solution.To this end, we propose a new biosensing molecule for biomedical sensor applications based on antibody-aptamer conjugates, designated as “Abtamers,” which includes advantages of both antibodies and aptamers; e.g. high sensitivity, selectivity with molecular dynamics upon target binding, facilitating signals for sensing. We propose to use insulin as a model target for an electrochemical sensor employing this novel biorecognition element. The electrochemical detection of insulin levels in persons with diabetes would provide another useful metric in diabetes technology, as insulin measurements are typically done via ELISA. Methods: The antibody-aptamer conjugate constructed utilized an insulin single chain variable fragment (scFv) and an insulin aptamer. To circumvent the non-optimal binding of polypeptides to oligonucleotides, we utilized the SpyCatcher/SpyTag complex as the bioconjugation system to couple the scFv to the aptamer in a one-to-one manner [3-4]. We created a recombinant fusion molecule of the insulin scFv and SpyCatcher, and created a SpyTag-insulin aptamer fusion molecule. The combination of these two fusion molecules results in an insulin antibody-insulin aptamer conjugate. We aim to employ this new MRE to detect insulin via square wave voltammetry. Results and Discussion: Through the binding of the two fusion molecules, we have created an irreversibly bound conjugate, conserving the structures of both the antibody and aptamer. The modification of a redox probe to the insulin aptamer domain in the Abtamer conjugate allows for a simple and facile method to create an electroactive biomolecule which can be immobilized to an electrode surface. We expect the binding affinity of this molecule to be higher towards specified targets due to both an antibody and aptamer binding event. Furthermore, the flexibility of the aptamer allows for conformational changes upon binding which can be exploited in electrochemical sensing applications. The developed insulin antibody-insulin aptamer conjugate can be applied as a biorecognition element for an electrochemical sensing platform, thereby realizing a unique biosensing principle, the “Abta-sensor”

Optimized culture conditions for bacterial cellulose production by Acetobacter senegalensis MA1

BackgroundCellulose, the most versatile biomolecule on earth, is available in large quantities from plants. However, cellulose in plants is accompanied by other polymers like hemicellulose, lignin, and pectin. On the other hand, pure cellulose can be produced by some microorganisms, with the most active producer being Acetobacter xylinum. A. senengalensis is a gram-negative, obligate aerobic, motile coccus, isolated from Mango fruits in Senegal, capable of utilizing a variety of sugars and produce cellulose. Besides, the production is also influenced by other culture conditions. Previously, we isolated and identified A. senengalensis MA1, and characterized the bacterial cellulose (BC) produced.ResultsThe maximum cellulose production by A. senengalensis MA1 was pre-optimized for different parameters like carbon, nitrogen, precursor, polymer additive, pH, temperature, inoculum concentration, and incubation time. Further, the pre-optimized parameters were pooled, and the best combination was analyzed by using Central Composite Design (CCD) of Response Surface Methodology (RSM). Maximum BC production was achieved with glycerol, yeast extract, and PEG 6000 as the best carbon and nitrogen sources, and polymer additive, respectively, at 4.5 pH and an incubation temperature of 33.5 °C. Around 20% of inoculum concentration gave a high yield after 30 days of inoculation. The interactions between culture conditions optimized by CCD included alterations in the composition of the HS medium with 50 mL L− 1 of glycerol, 7.50 g L− 1 of yeast extract at pH 6.0 by incubating at a temperature of 33.5 °C along with 7.76 g L− 1 of PEG 6000. This gave a BC yield of wet weight as 469.83 g L− 1.ConclusionThe optimized conditions of growth medium resulted in enhanced production of bacterial cellulose by A. senegalensis MA1, which is around 20 times higher than that produced using an unoptimized HS medium. Further, the cellulose produced can be used in food and pharmaceuticals, for producing high-quality paper, wound dressing material, and nanocomposite films for food packaging.

Nanobodies derived from Camelids represent versatile biomolecules for biomedical applications.

Nanobodies are antigen binding variable domains of heavy-chain antibodies without light-chains, and these biomolecules occur naturally in the serum of Camelidae species. Nanobodies have a compact structure and low molecular weight when compared with antibodies, and are the smallest active antigen-binding fragments. Because of their remarkable stability and manipulable characteristics, nanobodies have been incorporated into biomaterials and used as molecular recognition and tracing agents, drug delivery systems, molecular imaging tools and disease therapeutics. This review summarizes recent progress in this field focusing on nanobodies as versatile biomolecules for biomedical applications.

The chemistry and applications of RNA 2'-OH acylation.

RNA is a versatile biomolecule with a broad range of biological functions that go far beyond its initially described role as a simple information carrier. The development of chemical methods to control, manipulate and modify RNA has the potential to yield new insights into its many functions and properties. Traditionally, most of these methods involved the chemical modification of RNA structure using solid-state synthesis or enzymatic transformations. However, over the past 15 years, the direct functionalization of RNA by selective acylation of the 2'-hydroxyl (2'-OH) group has emerged as a powerful alternative that enables the simple modification of both synthetic and transcribed RNAs. In this Review, we discuss the chemical properties and design of effective reagents for RNA 2'-OH acylation, highlighting the unique problem of 2'-OH reactivity in the presence of water. We elaborate on how RNA 2'-OH acylation is being exploited to develop selective chemical probes that enable interrogation of RNA structure and function, and describe new developments and applications in the field.

Small-Molecule-Binding Riboswitches.

RNA is a versatile biomolecule capable of transferring information, taking on distinct three-dimensional shapes, and reacting to ambient conditions. RNA molecules utilize a wide range of mechanisms to control gene expression. An example of such regulation is riboswitches. Consisting exclusively of RNA, they are able to control important metabolic processes, thus providing an elegant and efficient RNA-only regulation system. Existing across all domains of life, riboswitches appear to represent one of the most highly conserved mechanisms for the regulation of a broad range of biochemical pathways. Through binding of a wide range of small-molecule ligands to their so-called aptamer domain, riboswitches undergo a conformational change in their downstream "expression platform." In consequence, the pattern of gene expression changes, which in turn results in increased or decreased protein production. Riboswitches unite the sensing and transduction of a signal that can directly be coupled to the metabolism of the cell; thus they constitute a very potent regulatory mechanism for many organisms. Highly specific RNA-binding domains not only occur in vivo but can also be evolved by means of the SELEX (systematic evolution of ligands by exponential enrichment) method, which allows in vitro selection of aptamers against almost any ligand. Coupling of these aptamers with an expression platform has led to the development of synthetic riboswitches, a highly active research field of great relevance and immense potential. The aim of this review is to summarize developments in the riboswitch field over the last decade and address key questions of recent research.