Research

Jump to: Review

12 pages, 2707 KiB

Open AccessArticle

MiRNA-Responsive CRISPR-Cas System via a DNA Regulator

by Dayoung Yun and Cheulhee Jung

Biosensors 2023, 13(11), 975; https://0-doi-org.brum.beds.ac.uk/10.3390/bios13110975 - 07 Nov 2023

Viewed by 1373

Clustered regularly interspaced short palindromic repeats (CRISPR)- CRISPR-associated protein 9 (Cas9) genome editing technology is widely used for gene editing because it provides versatility in genetic manipulation. Several methods for regulating CRISPR activity already exist for accurate editing, but these require complex engineering. [...] Read more.

Clustered regularly interspaced short palindromic repeats (CRISPR)- CRISPR-associated protein 9 (Cas9) genome editing technology is widely used for gene editing because it provides versatility in genetic manipulation. Several methods for regulating CRISPR activity already exist for accurate editing, but these require complex engineering. Thus, a simple and convenient regulatory system is required. In this study, we devised a CRISPR activation system using a DNA regulator that can be activated by miRNAs. The designed regulator was divided into two parts. The inhibition component consisted of the protospacer-adjacent motif (PAM) and seed sequence, which are important for Cas9 target recognition and bind to the ribonucleoprotein (RNP) complex for inhibition. The miRNA recognition component has a single-stranded toehold DNA for target miRNA binding and a partial double-stranded DNA complementary to the remaining miRNA sequence. In the presence of target miRNAs, the structure of the regulator is disrupted by the miRNAs, leading to its dissociation from the RNP complex and subsequent restoration of CRISPR activity. This method is easy to design and can be applied to various miRNAs via simple sequence manipulation. Therefore, this strategy provides a general platform for controlled genome editing. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures

Figure 1

14 pages, 12374 KiB

Open AccessArticle

NIR-II Absorbing Conjugated Polymer Nanotheranostics for Thermal Initiated NO Enhanced Photothermal Therapy

by Kaiwen Chang, Xiaolin Sun, Qiaofang Qi, Mingying Fu, Bing Han, Yang Zhang, Wei Zhao, Tianjun Ni, Qiong Li, Zhijun Yang and Chunpo Ge

Biosensors 2023, 13(6), 642; https://0-doi-org.brum.beds.ac.uk/10.3390/bios13060642 - 12 Jun 2023

Cited by 3 | Viewed by 1485

Abstract

Photothermal therapy (PTT) has received constant attention as a promising cancer treatment. However, PTT-induced inflammation can limit its effectiveness. To address this shortcoming, we developed second near-infrared (NIR-II) light-activated nanotheranostics (CPNPBs), which include a thermosensitive nitric oxide (NO) donor (BNN6) to enhance PTT. [...] Read more.

Photothermal therapy (PTT) has received constant attention as a promising cancer treatment. However, PTT-induced inflammation can limit its effectiveness. To address this shortcoming, we developed second near-infrared (NIR-II) light-activated nanotheranostics (CPNPBs), which include a thermosensitive nitric oxide (NO) donor (BNN6) to enhance PTT. Under a 1064 nm laser irradiation, the conjugated polymer in CPNPBs serves as a photothermal agent for photothermal conversion, and the generated heat triggers the decomposition of BNN6 to release NO. The combination of hyperthermia and NO generation under single NIR-II laser irradiation allows enhanced thermal ablation of tumors. Consequently, CPNPBs can be exploited as potential candidates for NO-enhanced PTT, holding great promise for their clinical translational development. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures

Figure 1

11 pages, 2235 KiB

Open AccessArticle

A Magnetoelectrochemical Bioassay for Highly Sensitive Sensing of Point Mutations in Interleukin-6 Gene Using TMB as a Hybridization Intercalation Indicator

by Sabrine Baachaoui, Mohamed Mastouri, Maroua Meftah, Basma Yaacoubi-Loueslati and Noureddine Raouafi

Biosensors 2023, 13(2), 240; https://0-doi-org.brum.beds.ac.uk/10.3390/bios13020240 - 08 Feb 2023

Cited by 5 | Viewed by 1672

Abstract

Point mutations are common in the human DNA genome and are closely related to higher susceptibility to cancer diseases. Therefore, suitable methods for their sensing are of general interest. In this work, we report on a magnetic electrochemical bioassay using DNA probes tethered [...] Read more.

Point mutations are common in the human DNA genome and are closely related to higher susceptibility to cancer diseases. Therefore, suitable methods for their sensing are of general interest. In this work, we report on a magnetic electrochemical bioassay using DNA probes tethered to streptavidin magnetic beads (strep-MBs) to detect T > G single nucleotide polymorphism (SNP) within the inteleukin-6 (IL6) gene in human genomic DNA. In the presence of the target DNA fragment and tetramethylbenzidine (TMB), the electrochemical signal related to the oxidation of TMB is observed, which is much higher than the one obtained in the absence of the target. The key parameters affecting the analytical signal, such as the concentration of the biotinylated probe, its incubation time with strep-MBs, DNA hybridization time, and TMB loading, were optimized using the electrochemical signal intensity and signal-to-blank (S/B) ratio as selection criteria. Using spiked buffer solutions, the bioassay can detect the mutated allele in a wide range of concentrations (over six decades) with a low detection limit (7.3 fM). Furthermore, the bioassay displays a high specificity with high concentrations of the major allele (one mismatched), and two mismatched and non–complementary DNA. More importantly, the bioassay can detect the variation in scarcely diluted human DNA, collected from 23 donors, and can reliably distinguish between heterozygous (TG genotype) and homozygous (GG genotype) in respect to the control subjects (TT genotype), where the differences are statistically highly significant (p-value < 0.001). Thus, the bioassay is useful for cohort studies targeting one or more mutations in human DNA. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures

Figure 1

11 pages, 5404 KiB

Open AccessArticle

Rapid and Sensitive Diagnosis of COVID-19 Using an Electricity-Free Self-Testing System

by Sheng Li, Wenlong Guo, Minmin Xiao, Yulin Chen, Xinyi Luo, Wenfei Xu, Jianhua Zhou and Jiasi Wang

Biosensors 2023, 13(2), 180; https://0-doi-org.brum.beds.ac.uk/10.3390/bios13020180 - 23 Jan 2023

Viewed by 1691

Abstract

Rapid and sensitive detection of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for early diagnosis and effective treatment. Nucleic acid testing has been considered the gold standard method for the diagnosis of COVID-19 for its [...] Read more.

Rapid and sensitive detection of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for early diagnosis and effective treatment. Nucleic acid testing has been considered the gold standard method for the diagnosis of COVID-19 for its high sensitivity and specificity. However, the polymerase chain reaction (PCR)-based method in the central lab requires expensive equipment and well-trained personnel, which makes it difficult to be used in resource-limited settings. It highlights the need for a sensitive and simple assay that allows potential patients to detect SARS-CoV-2 by themselves. Here, we developed an electricity-free self-testing system based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) that allows for rapid and accurate detection of SARS-CoV-2. Our system employs a heating bag as the heat source, and a 3D-printed box filled with phase change material (PCM) that successfully regulates the temperature for the RT-LAMP. The colorimetric method could be completed in 40 min and the results could be read out by the naked eye. A ratiometric measurement for exact readout was also incorporated to improve the detection accuracy of the system. This self-testing system is a promising tool for point-of-care testing (POCT) that enables rapid and sensitive diagnosis of SARS-CoV-2 in the real world and will improve the current COVID-19 screening efforts for control and mitigation of the pandemic. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures

Figure 1

17 pages, 6338 KiB

Open AccessArticle

BODIPY-Based Fluorescent Probes for Selective Visualization of Endogenous Hypochlorous Acid in Living Cells via Triazolopyridine Formation

by Peraya Hiranmartsuwan, Sirilak Wangngae, Jukkrit Nootem, Anyanee Kamkaew, Rathawat Daengngern, Worawat Wattanathana and Kantapat Chansaenpak

Biosensors 2022, 12(11), 923; https://0-doi-org.brum.beds.ac.uk/10.3390/bios12110923 - 25 Oct 2022

Cited by 2 | Viewed by 2041

Abstract

In this work, the two pyridylhydrazone-tethered BODIPY compounds (2 and 3) were synthesized. These compounds aimed to detect hypochlorous acid (HOCl) species via cyclic triazolopyridine formation. The open forms and the resulting cyclic forms of BODIPYs (2, 3, [...] Read more.

In this work, the two pyridylhydrazone-tethered BODIPY compounds (2 and 3) were synthesized. These compounds aimed to detect hypochlorous acid (HOCl) species via cyclic triazolopyridine formation. The open forms and the resulting cyclic forms of BODIPYs (2, 3, 4, and 5) were fully characterized by nuclear magnetic resonance, mass spectrometry, infrared spectroscopy, and single-crystal X-ray diffraction. These two probes can selectively detect HOCl through a fluorescence turn-on mechanism with the limit of detections of 0.21 µM and 0.77 µM for compounds 2 and 3, respectively. This fluorescence enhancement phenomenon could be the effect from C = N isomerization inhibition due to HOCl-triggered triazolopyridine formation. In cell imaging experiments, these compounds showed excellent biocompatibility toward RAW 264.7 murine live macrophage cells and greatly visualized endogenous HOCl in living cells stimulated with lipopolysaccharide. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures

Figure 1

11 pages, 2914 KiB

Open AccessArticle

Rational Construction of a Mitochondria-Targeted Reversible Fluorescent Probe with Intramolecular FRET for Ratiometric Monitoring Sulfur Dioxide and Formaldehyde

by Jinxiao Lyu, Chunfei Wang and Xuanjun Zhang

Biosensors 2022, 12(9), 715; https://0-doi-org.brum.beds.ac.uk/10.3390/bios12090715 - 03 Sep 2022

Cited by 4 | Viewed by 1493

Abstract

Sulfur dioxide (SO₂) and formaldehyde (FA) are important species that maintain redox homeostasis in life and are closely related to many physiological and pathological processes. Therefore, it is of great significance to realize the reversible monitoring of them at the intracellular [...] Read more.

Sulfur dioxide (SO₂) and formaldehyde (FA) are important species that maintain redox homeostasis in life and are closely related to many physiological and pathological processes. Therefore, it is of great significance to realize the reversible monitoring of them at the intracellular level. Here, we synthesized a reversible ratiometric fluorescent probe through a reasonable design, which can sensitively monitor SO₂ derivatives and FA, and the detection limit can reach 0.16 μM. The probe can specifically target mitochondria and successfully monitor the fluctuations of SO₂ and FA in living cells. It also works well in the detection of SO₂ and FA in zebrafish. This high-performance probe is expected to find broad in vitro and in vivo applications. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures

Figure 1

14 pages, 3122 KiB

Open AccessArticle

Photoacoustic/Ultrasound Endoscopic Imaging Reconstruction Algorithm Based on the Approximate Gaussian Acoustic Field

by Yongjun Wang, Chuqi Yuan, Jinsheng Jiang, Kuan Peng and Bo Wang

Biosensors 2022, 12(7), 463; https://0-doi-org.brum.beds.ac.uk/10.3390/bios12070463 - 27 Jun 2022

Cited by 4 | Viewed by 1767

Abstract

This paper aims to propose a new photoacoustic/ultrasound endoscopic imaging reconstruction algorithm based on the approximate Gaussian acoustic field which significantly improves the resolution and signal-to-noise ratio (SNR) of the out-of-focus region. We demonstrated the method by numerical calculations and investigated the applicability [...] Read more.

This paper aims to propose a new photoacoustic/ultrasound endoscopic imaging reconstruction algorithm based on the approximate Gaussian acoustic field which significantly improves the resolution and signal-to-noise ratio (SNR) of the out-of-focus region. We demonstrated the method by numerical calculations and investigated the applicability of the algorithm in a chicken breast phantom. The validation was finally performed by the rabbit rectal endoscopy experiment. Simulation results show that the lateral resolution of the target point in the out-of-focus region can be well optimized with this new algorithm. Phantom experimental results show that the lateral resolution of the indocyanine green (ICG) tube in the photoacoustic image is reduced from 3.975 mm to 1.857 mm by using our new algorithm, which is a 52.3% improvement. Ultrasound images also show a significant improvement in lateral resolution. The results of the rabbit rectal endoscopy experiment prove that the algorithm we proposed is capable of providing higher-quality photoacoustic/ultrasound images. In conclusion, the algorithm enables fast acoustic resolution photoacoustic/ ultrasonic dynamic focusing and effectively improves the imaging quality of the system, which has significant guidance for the design of acoustic resolution photoacoustic/ultrasound endoscopy systems. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures

Figure 1

Review

Jump to: Research

24 pages, 5328 KiB

Open AccessReview

Molecularly Imprinted Polymer-Based Luminescent Chemosensors

by Ruoyang Liu and Chi-Chiu Ko

Biosensors 2023, 13(2), 295; https://0-doi-org.brum.beds.ac.uk/10.3390/bios13020295 - 19 Feb 2023

Cited by 7 | Viewed by 2372

Abstract

Molecularly imprinted polymer (MIP)-based luminescent chemosensors combine the advantages of the highly specific molecular recognition of the imprinting sites and the high sensitivity with the luminescence detection. These advantages have drawn great attention during the past two decades. Luminescent molecularly imprinted polymers (luminescent [...] Read more.

Molecularly imprinted polymer (MIP)-based luminescent chemosensors combine the advantages of the highly specific molecular recognition of the imprinting sites and the high sensitivity with the luminescence detection. These advantages have drawn great attention during the past two decades. Luminescent molecularly imprinted polymers (luminescent MIPs) towards different targeted analytes are constructed with different strategies, such as the incorporation of luminescent functional monomers, physical entrapment, covalent attachment of luminescent signaling elements on the MIPs, and surface-imprinting polymerization on the luminescent nanomaterials. In this review, we will discuss the design strategies and sensing approaches of luminescent MIP-based chemosensors, as well as their selected applications in biosensing, bioimaging, food safety, and clinical diagnosis. The limitations and prospects for the future development of MIP-based luminescent chemosensors will also be discussed. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures

Figure 1

18 pages, 8127 KiB

Open AccessReview

Recent Advances of NIR-II Emissive Semiconducting Polymer Dots for In Vivo Tumor Fluorescence Imaging and Theranostics

by Qidong Wei, Dingshi Xu, Tianyu Li, Xuehan He, Jiasi Wang, Yi Zhao and Lei Chen

Biosensors 2022, 12(12), 1126; https://0-doi-org.brum.beds.ac.uk/10.3390/bios12121126 - 05 Dec 2022

Cited by 5 | Viewed by 2185

Abstract

Accurate diagnosis and treatment of tumors, one of the top global health problems, has always been the research focus of scientists and doctors. Near-infrared (NIR) emissive semiconducting polymers dots (Pdots) have demonstrated bright prospects in field of in vivo tumor fluorescence imaging owing [...] Read more.

Accurate diagnosis and treatment of tumors, one of the top global health problems, has always been the research focus of scientists and doctors. Near-infrared (NIR) emissive semiconducting polymers dots (Pdots) have demonstrated bright prospects in field of in vivo tumor fluorescence imaging owing to some of their intrinsic advantages, including good water-dispersibility, facile surface-functionalization, easily tunable optical properties, and good biocompatibility. During recent years, much effort has been devoted to developing Pdots with emission bands located in the second near-infrared (NIR-II, 1000–1700 nm) region, which hold great advantages of higher spatial resolution, better signal-to-background ratios (SBR), and deeper tissue penetration for solid-tumor imaging in comparison with the visible region (400–680 nm) and the first near-infrared (NIR-I, 680–900 nm) window, by virtue of the reduced tissue autofluorescence, minimal photon scattering, and low photon absorption. In this review, we mainly summarize the latest advances of NIR-II emissive semiconducting Pdots for in vivo tumor fluorescence imaging, including molecular engineering to improve the fluorescence quantum yields and surface functionalization to elevate the tumor-targeting capability. We also present several NIR-II theranostic Pdots used for integrated tumor fluorescence diagnosis and photothermal/photodynamic therapy. Finally, we give our perspectives on future developments in this field. Full article

(This article belongs to the Special Issue Activatable Probes for Biosensing, Imaging, and Photomedicine)

► Show Figures