Precise visualization and ROS-dependent photodynamic therapy of colorectal cancer with a novel mitochondrial viscosity photosensitive fluorescent probe

BACKGROUND

Colorectal cancer (CRC) is a prominent global cancer with high mortality rates among human beings. Efficient diagnosis and treatment have always been a challenge for CRC management. Fluorescence guided cancer therapy, which combines diagnosis with therapy into one platform, has brought a new chance for achieving precise cancer theranostics. Among this, photosensitizers, applied in photodynamic therapy (PDT), given the integration of real-time imaging capacity and efficacious treatment feasibility, show great potential to serve as remarkable tools. Although much effort has been put into constructing photosensitizers for locating and destroying CRC cells, it is still in high need to develop novel photosensitizers to attain specific detection and fulfil effective therapy.

METHODS

Probe HTI was rational synthesized for the diagnosis and treatment of CRC. Spectrometric determination was carried out first, followed by the 1O2 generation ability test. Then, HTI was displayed in distinguishing CRC cells from normal cells Further, the PDT effect of the photosensitizer was studied in vitro. Additionally, HTI was used in CRC BALB/c nude mice model to validate its viscosity labelling and tumor suppression characteristics.

RESULTS

We successfully fabricated a mitochondrial targeting probe, HTI, together with remarkable viscosity sensitivity, ultralow background interference, and excellent 1O2 generation capacity. HTI was favorably applied to the viscosity detection, displaying a 11-fold fluorescent intensity enhancement in solvents from 1.57 cp to 2043 cp. Then, it was demonstrated that HTI could distinguish CRC cells from normal cells upon the difference in mitochondrial viscosity. Moreover, HTI was qualified for producing 1O2 with high efficiency in cells, supported by the sparkling signals of DCFH after incubation with HTI under light irradiation. More importantly, the viscosity labelling and tumor suppression performance in CRC CDX model was determined, enriching the multifunctional validation of HTI in vivo.

CONCLUSIONS

In this study, HTI was demonstrated to show a sensitive response to mitochondrial viscosity and possess a high 1O2 generation capacity. Both in vitro cell imaging and in vivo tumor treatment trials proved that HTI was effectively served as a robust scaffold for tumor labeling and CRC cells clearance. This breakthrough discovery held immense potential for advancing the early diagnosis and management of CRC through PDT. By leveraging HTI's properties, medical professionals could benefit from improved diagnostic accuracy and targeted treatment in CRC management, ultimately leading to enhanced patient outcomes.

Fidelity-oriented fluorescence imaging probes for beta-galactosidase: From accurate diagnosis to precise treatment

Beta-galactosidase (β-gal), a typical glycosidase catalyzing the hydrolysis of glycosidic bonds, is regarded as a vital biomarker for cell senescence and cancer occurrence. Given the advantages of high spatiotemporal resolution, high sensitivity, non-invasiveness, and being free of ionizing radiations, fluorescent imaging technology provides an excellent choice for in vivo imaging of β-gal. In this review, we detail the representative biotech advances of fluorescence imaging probes for β-gal bearing diverse fidelity-oriented improvements to elucidate their future potential in preclinical research and clinical application. Next, we propose the comprehensive design strategies of imaging probes for β-gal with respect of high fidelity. Considering the systematic implementation approaches, a range of high-fidelity imaging-guided theragnostic are adopted for the individual β-gal-associated biological scenarios. Finally, current challenges and future trends are proposed to promote the next development of imaging agents for individual and specific application scenarios.

Functional insights from targeted imaging BACE1: the first near-infrared fluorescent probe for Alzheimer's disease diagnosis

BACKGROUND

β-Secretase (BACE1) is the vital enzyme in the pathogenic processes of Alzheimer's disease (AD). However, the development of a powerful tool with sensitivity for BACE1 determination in vivo is a challenge.

METHODS

A novel NIR fluorescent probe HBAE was synthetized from 2-hydroxy-3-methylbenzaldehyde and 2-amino-benzenethiol by 5 steps. The fluorescence mechanism in the ESIPT systems of HBAE probe was insighted with time-dependent density functional theory (TD-DFT) at the TDPBE0 level with the def2-TZVP approach. The corresponding docking between HBAE and BACE1 (PDB: 5I3Y) was performed through the ducking method by DOCK6.8. Then the BBB permeability of HBAE is verified by transwell orifice plate. 22-month-old male AD-model (5XFAD) mice and age-matched wild-type mice were employed to observe the brain kinetics by intravenous injection. Finally, Immunohistochemistry was performed on the AD brain section to reveal the levels of BACE1 in hippocampus and cortex areas and other regions in AD mice through the brain tissue slices by HBAE.

RESULTS

The NIR fluorescent probe HBAE was successfully applied in imaging BACE1 in AD model mice. The capability of HBAE in reflecting different level of BACE1 was performed by the specific imaging of the hippocampus region.

CONCLUSIONS

We reported the first ESIPT near-infrared fluorescence probe HBAE for monitoring endogenous BACE1 in the AD live model mice, thus offering a versatile chemical tool for visualizing in the pathological processes of AD live brains. Remarkably, high resolution images showed the localization of red fluorescence stains in hippocampus of the AD brain. This study provides a promising way for functional insights from protein BACE1 in vivo.

NIR-I Dye-Based Probe: A New Window for Bimodal Tumor Theranostics

Near-infrared (NIR, 650–1700 nm) bioimaging has emerged as a powerful strategy in tumor diagnosis. In particular, NIR-I fluorescence imaging (650–950 nm) has drawn more attention, benefiting from the high quantum yield and good biocompatibility. Since their biomedical applications are slightly limited by their relatively low penetration depth, NIR-I fluorescence imaging probes have been under extensive development in recent years. This review summarizes the particular application of the NIR-I fluorescent dye-contained bimodal probes, with emphasis on related nanoprobes. These probes have enabled us to overcome the drawbacks of individual imaging modalities as well as achieve synergistic imaging. Meanwhile, the application of these NIR-I fluorescence-based bimodal probes for cancer theranostics is highlighted.

Highly selective and sensitive detection of arsenite ions(III) using a novel tetraphenylimidazole-based probe

More than 200 million people in the world are exposed to areas where the arsenic concentration exceeds the limit allowed for living species, which urges researchers to develop low-cost methods for the selective and fast detection of arsenic ions in environmental samples. Herein, we report a novel tetraphenylimidazole-based probe (TBAB) functionalized with a Schiff base for sensing and detecting arsenic ions in aqueous media. Upon the addition of arsenic ions, an obvious fluorescence change from faint yellow to green was observed visible to the naked eye. The probe can detect arsenic selectively in the presence of interfering substances, with a lower detection limit than 0.7 ppb, a value which is far lower than the limit set by the WHO. A detailed mechanism revealed that the chelation of TBAB with arsenic activated the AIE characteristic, leading to the enhanced fluorescence, which was verified by Job's plot experiment and HRMS. Its practicality was further validated by the analysis of real water samples, demonstrating its potential application for on-site detection and biological application.

Construction and theoretical insights into the ESIPT fluorescent probe for imaging formaldehyde in vitro and in vivo

We report the first ESIPT-based probe ABTB, for the highly sensitive and selective imaging of formaldehyde (FA). The various theoretical calculations have been systematically performed, and clearly unravel the lighting mechanism of the fluorescent probe for FA. Additionally, the probe was successfully applied in monitoring endogenous FA in the brain of AD mice.

Wash-free 3D imaging and detection of glioma with a novel neuropotential targeted AIE probe

Schematic illustration of a self-assembled nanoprobe (TPIG-NP) to exert imaging of glioma.

Fluorescent probes for the detection of magnesium ions (Mg2+): from design to application

Magnesium ions (Mg²⁺) play essential roles in various physiological and pathological processes, its abnormal homeostasis in cells is related to many diseases, such as diabetes, neuromuscular disorders, hypertension and other cardiovascular disorders. Investigation on the regulation of magnesium in cellular processes has attracted considerable interest in the past several decades. Among those reported strategies, fluorescent imaging technology has become a powerful and cost-effective tool for the real-time monitoring of magnesium distribution, uptake and trafficking, due to its superior features of high sensitivity and non-invasiveness, as well as excellent spatial and temporal fidelity. Herein, we critically summarize the progresses in the intracellular magnesium detection with fluorescent imaging probes. Our discussion focuses on the recent contributions concerning fluorescent imaging probes for mapping magnesium in biological processes. All the candidates are organized according to their acceptor structures. The sensing mechanisms of fluorescent probes are also highly taken into account. Challenges, trends and prospects of fluorescent imaging technology in magnesium detection are also set forth.

Herein, progress in intracellular magnesium detection with fluorescent probes is critically summarized in this work.

Applications of Nanoparticles Probes for Prostate Cancer Imaging and Therapy

Prostate cancer (PCa) is the most common type of cancer in men with high morbidity and mortality. However, the current treatment with drugs often leads to chemotherapy resistance. It is known that the multi-disciplines research on molecular imaging is very helpful for early diagnosing, staging, restaging and precise treatment of PCa. In the past decades, the tumor-specific targeted drugs were developed for the clinic to treat prostate cancer. Among them, the emerging nanotechnology has brought about many exciting novel diagnosis and treatments systems for PCa. Nanotechnology can greatly enhance the treatment activity of PCa and provide novel theranostics platform by utilizing the unique physical/chemical properties, targeting strategy, or by loading with imaging/therapeutic agents. Herein, this chapter focuses on state-of-art advances in imaging and diagnosing PCa with nanomaterials and highlights the approaches used for functionalization of the targeted biomolecules, and in the treatment for various aspects of PCa with multifunctional nanoparticles, nanoplatforms and nanodelivery system.

Fluorescent probes and materials for detecting formaldehyde: from laboratory to indoor for environmental and health monitoring

Formaldehyde (FA), as a vital industrial chemical, is widely used in building materials and numerous living products.

Advances of Molecular Imaging for Monitoring the Anatomical and Functional Architecture of the Olfactory System

The olfactory system of organisms serves as a genetically and anatomically model for studying how sensory input can be translated into behavior output. Some neurologic diseases are considered to be related to olfactory disturbance, especially Alzheimer's disease, Parkinson's disease, multiple sclerosis, and so forth. However, it is still unclear how the olfactory system affects disease generation processes and olfaction delivery processes. Molecular imaging, a modern multidisciplinary technology, can provide valid tools for the early detection and characterization of diseases, evaluation of treatment, and study of biological processes in living subjects, since molecular imaging applies specific molecular probes as a novel approach to produce special data to study biological processes in cellular and subcellular levels. Recently, molecular imaging plays a key role in studying the activation of olfactory system, thus it could help to prevent or delay some diseases. Herein, we present a comprehensive review on the research progress of the imaging probes for visualizing olfactory system, which is classified on different imaging modalities, including PET, MRI, and optical imaging. Additionally, the probes' design, sensing mechanism, and biological application are discussed. Finally, we provide an outlook for future studies in this field.

Upconversion nanocomposites for photo-based cancer theranostics

Upconversion nanoparticles (UCNPs) are able to convert long wavelength excitation light into high energy ultraviolet (UV) or visible emissions, and they have attracted significant attention because of their distinct photochemical properties including sharp emission bands, low autofluorescence, high tissue penetration depth and minimal photodamage to tissues.

Cloning and characterization of a novel member of human beta-1,4-galactosyltransferase gene family

By using the EST strategy for identifying novel members belonging to homologous gene families, a novel fulklength cDNA encoding a protein significantly homologous to UDP-Gal: N-acetylglucosamine beta-1, 4-galactosyltransferase (GalT) was isolated from a human testis cDNA library. A nucleotide sequence of 2 173 bp long was determined to contain an open reading frame of 1 032 nucleotides (344 amino acids). In view of the homology to memben of the galactosyltransferase gene family and especially the closest relationship toGallus gallus GalT type I (CK I), the predicted product of the novel cDNA was designated as human beta-1,4-galactosyltransferase homolog I (HumGT-H1). Its mRNA is present in different degrees in 16 tissues examined. Southern analysis of human genomic DNA revealed its locus on chromosome 3.

Application of cumulative odds logistic model on risk factors analysis for sexually transmitted infections among female sex workers in Kaiyuan city, Yunnan province, China

OBJECTIVES

To investigate the epidemiology of sexually transmitted infections (STI) among female sex workers (FSW) in Kaiyuan city, Yunnan province, China, and to identify risk factors associated with STI.

METHODS

A cross-sectional study of 737 FSW was carried out from March to May 2006, with confidential interviews and laboratory tests for STI. A cumulative logit model was used to evaluate the risk factors for STI.

RESULTS

The overall prevalence of HIV is 10.3%. The prevalence of syphilis, herpes simplex virus type 2, gonorrhoea, chlamydia and trichomonas was 7.5%, 68.1%, 8.3%, 25.9% and 10.6%, respectively. In multivariate cumulative odds logistic analysis, the factors associated with STI were education level, living in the entertainment location, injection drug use, non-injection drug use, over five clients in the previous week and inconsistent use of condoms with clients.

CONCLUSION

The findings highlight the gravity of the STI epidemic among FSW in China, where sexual transmission has now overtaken unsafe injection practices as the dominant mode of HIV transmission. Targeted intervention programmes for FSW should focus on increasing condom use, strengthening knowledge and awareness of STI/HIV and encouraging routine screening and treatment-seeking behaviours. Reducing the spread of STI also has profound implications for the prevention of HIV.

Modeling and analysis of the structure of the thermostable catechol 2,3-dioxygenase from Bacillus Stearothermophilus

The three-dimensional structure of thermostable catechol 2,3-dioxygenase(TC230) from Bacillus Stearothermophilus has been modeled basing on the known x-ray structure of catechol 2,3-dioxygenase(metapyrocatechase) from Pseudomonas putida mt-2, using computer graphics energy minimization techniques. The rationality of the resulting model was validated by Ramachandran plot and Profile-3D. The structure-functionally important residues, such as M++ binding residues and the substrate binding residues, were identified from the model. These residues are candidates for further site-directed mutagenesis experiments. The reason that the thermostability of TC230 is greater than metapyrocatechase(MPC) has been found, which may be due to the specific structure of the TC230 in the C-end mainly.

[An observation on long-term influence of middle ear bacterial infection on inner ear function and systemic immune reaction]

OBJECTIVE

To understand whether long-term inner ear heat shock response related to heat shock protein(HSP70) caused by middle ear bacterial infection and the potential influence on inner ear function.

METHODS

Sixty BALB/c mice were randomly classified into 6 groups including Klebsiella pneumoniae (KP), Staphylococcus aureus, Bacillus pyocyaneus, Bacillus coli, Bacillus proteus and physiological saline control groups. On 135 days after injection, distortion product otoacoustic emissions(DPOAE) was tested and all the samples were collected, which were examined with light and electronic microscopes. HSP70 related molecule expression in inner ear, nuclear factor (NF) kappa Bp65 characterization in mononuclear cell, anti-KP antibody and anti-membranous labyrinth proteins (MLP) were examined.

RESULTS

No nuclear transfer of NF kappa Bp65 was observed in any animal. Anti-KP antibody was detected in 30% (3/10) of Staphylococcus aureus group, 29% (2/7) of KP group, 33% (3/9) of Bacillus pyocyaneus group and 10% (1/10) of control group. Anti-MLP antibody was created in 20% (2/10) of Staphylococcus aureus group, 20% (2/10) of KP group, one each in Bacillus pyocyaneus group and control group respectively. Double positive antibody against KP and MLP were found in Staphylococcus aureus group and KP group. When analyzed with Western blot, all the positive bands were small molecules including strongest 26,000-30,000, medium degree 38,000-41,000 and weak 46,000-50,000 except for 68,000 in one case. There was only one significant DPOAE amplification decrease at 1,625 Hz (2f1-f2) in left ear of Bacillus pyocyaneus group and right ear of Bacillus proteus group. No abnormal phenomenon was found in inner ear both under light microscope and electronic microscope. No significant expression of HSP70 was observed in inner ears.

CONCLUSION

No long-term heat shock response related to HSP70 existed in the inner ear and the immune inner ear damage may be caused by multiplefactors.

[A novel method for screening anti-inner ear autoantibody in patients with autoimmune diseases]

OBJECTIVE

To appraise the clinical value of a newly established method, rapid electric field immobilizing liquid phase molecule dot blot analysis (REILMD), for screening anti-inner ear autoantibody in patients with autoimmune diseases.

METHODS

Seventy-one patients with 11 kinds of autoimmune diseases were chosen for the study. Both the general immunity and autoantibodies were tested. In the processes of detection of anti-inner ear autoantibody, REILMD was used for screening, and then the Western blot was used to define the molecular weight of inner ear antigen recognized by the positive autoantibody.

RESULTS

Acceleration of erythrocyte sedimentation rate (ES), positive rheumatoid factor (RF), increases in C reactive protein (CRP), IgG and circulating immune complex (CIC) were found in most cases with rheumatoid arthritis (RA) and systemic lupus erythematodes (SLE). Some of these patients had increased IgA, IgM and C4. Two of 16 RA had anti-double-stranded DNA (dsDNA) and anti-mitochondria and 4/16 had anti-nucleus antibodies. Eleven of 16 SLE had antinucleus, 7/13 had anti-ribonucleoprotein (RNP), anti-Sjögren syndrome A (SSA) and anti-dsDNA, 3/13 had anti-smooth muscle (Sm) and 1/13 had anti-DNA topoisomerase I (Scl)-70, striated muscle and stomach acid cell antibodies. No autoantibody was detected in AS. Anti-inner ear autoantibody existed in 9 out of 71 patients (13%) with autoimmune diseases, in 2 of 21 patients (10%) with sudden deafness and only in 1 of 48 control subjects (2%, coronary heart disease). The anti-inner ear autoantibody was positive in 5 of 16 (31%) patients with SLE and 1 each in RA, AS, Behset's disease and streptococcus infection syndrome. In patients with positive anti-inner ear antibody, 67% had anti-nucleus antibody, 50% had anti-RNP and dsDNA antibody. The molecules recognized by the positive anti-inner ear antibody were defined as 52,000, 36,000, 31,000 and 15,000 molecules of inner ear antigen.

CONCLUSION

REILMD is a feasible and easy method for screening anti-inner ear autoantibody. Several autoimmune diseases, particularly SLE, may be implicated in damage to the inner ear.