Chemical & Biomedical Imaging最新文献

Lung cancer, the most common cause of cancer-related death in the United States, requires advanced intraoperative detection methods to improve evaluation of surgical margins. In this study we employed DDAO-arachidonate (DDAO-A), a phospholipase A2 (PLA2) activatable fluorophore, designed for the specific optical identification of lung cancers in real-time during surgery. The in vitro fluorescence activation of DDAO-A by porcine sPLA2 was tested in various liposomal formulations, with 100 nm extruded EggPC showing the best overall characteristics. Extruded EggPC liposomes containing DDAO-A were tested for their stability under various storage conditions, demonstrating excellent stability for up to 4 weeks when stored at −20 °C or below. Cell studies using KLN 205 and LLC1 lung cancer cell lines showed DDAO-A activation was proportional to cell number. DDAO-A showed preferential activation by human recombinant cPLA2, an isoform highly specific to arachidonic acid-containing lipids, when compared to a control probe, DDAO palmitate (DDAO-P). In vivo studies with DBA/2 mice bearing KLN 205 lung tumors recapitulated these results, with preferential activation of DDAO-A relative to DDAO-P following intratumoral injection. Topical application of DDAO-A-containing liposomes to human (n = 10) and canine (n = 3) lung cancers ex vivo demonstrated the preferential activation of DDAO-A in tumor tissue relative to adjacent normal lung tissue, with fluorescent tumor-to-normal ratios (TNR) of up to 5.2:1. The combined results highlight DDAO-A as a promising candidate for clinical applications, showcasing its potential utility in intraoperative and back-table imaging and topical administration during lung cancer surgeries. By addressing the challenge of residual microscopic disease at resection margins and offering stability in liposomal formulations, DDAO-A emerges as a potentially valuable tool for advancing precision lung cancer surgery and improving curative resection rates.

Lung cancer, the most common cause of cancer-related death in the United States, requires advanced intraoperative detection methods to improve evaluation of surgical margins. In this study we employed DDAO-arachidonate (DDAO-A), a phospholipase A2 (PLA2) activatable fluorophore, designed for the specific optical identification of lung cancers in real-time during surgery. The in vitro fluorescence activation of DDAO-A by porcine sPLA2 was tested in various liposomal formulations, with 100 nm extruded EggPC showing the best overall characteristics. Extruded EggPC liposomes containing DDAO-A were tested for their stability under various storage conditions, demonstrating excellent stability for up to 4 weeks when stored at -20 °C or below. Cell studies using KLN 205 and LLC1 lung cancer cell lines showed DDAO-A activation was proportional to cell number. DDAO-A showed preferential activation by human recombinant cPLA2, an isoform highly specific to arachidonic acid-containing lipids, when compared to a control probe, DDAO palmitate (DDAO-P). In vivo studies with DBA/2 mice bearing KLN 205 lung tumors recapitulated these results, with preferential activation of DDAO-A relative to DDAO-P following intratumoral injection. Topical application of DDAO-A-containing liposomes to human (n = 10) and canine (n = 3) lung cancers ex vivo demonstrated the preferential activation of DDAO-A in tumor tissue relative to adjacent normal lung tissue, with fluorescent tumor-to-normal ratios (TNR) of up to 5.2:1. The combined results highlight DDAO-A as a promising candidate for clinical applications, showcasing its potential utility in intraoperative and back-table imaging and topical administration during lung cancer surgeries. By addressing the challenge of residual microscopic disease at resection margins and offering stability in liposomal formulations, DDAO-A emerges as a potentially valuable tool for advancing precision lung cancer surgery and improving curative resection rates.

In the realm of nanomaterials, atomically precise quasi-molecular gold nanoclusters (AuNCs) play a prime role due to their unique, stable, and highly tunable optical properties. They are extensively structure-engineered for modulation of surface electronic states toward long wavelength photoluminescence, particularly in the NIR-II (1000 to 1700 nm) window. Contrast agents with NIR-II emission can potentially transform optical imaging in terms of higher spatial resolution, deeper tissue penetration, and reduced tissue autofluorescence. These advantages allow real-time imaging in living organisms for observing disease progression and treatment response. In this short review, we discuss origin of NIR-II emission in rationally designed AuNCs and their application toward high resolution imaging of vasculatures and hard and soft tissue structures for identification of pathological conditions such as stroke and injury. Further, recent employment of these AuNCs in the rapidly growing field of tumor theranostics is also summarized. Final remarks are provided on the scope for improvement in their optical properties and persisting challenges for clinical translation.

Genome maintenance comprises a group of complex and interrelated processes crucial for preserving and safeguarding genetic information within all organisms. Key aspects of genome maintenance involve DNA replication, transcription, recombination, and repair. Improper regulation of these processes could cause genetic changes, potentially leading to antibiotic resistance in bacterial populations. Due to the complexity of these processes, ensemble averaging studies may not provide the level of detail required to capture the full spectrum of molecular behaviors and dynamics of each individual biomolecule. Therefore, researchers have increasingly turned to single-molecule approaches, as these techniques allow for the direct observation and manipulation of individual biomolecules, and offer a level of detail that is unattainable with traditional ensemble methods. In this review, we provide an overview of recent in vitro and in vivo single-molecule imaging approaches employed to study the complex processes involved in prokaryotic genome maintenance. We will first highlight the principles of imaging techniques such as total internal reflection fluorescence microscopy and atomic force microscopy, primarily used for in vitro studies, and highly inclined and laminated optical sheet and super-resolution microscopy, mainly employed in in vivo studies. We then demonstrate how applying these single-molecule techniques has enabled the direct visualization of biological processes such as replication, transcription, DNA repair, and recombination in real time. Finally, we will showcase the results obtained from super-resolution microscopy approaches, which have provided unprecedented insights into the spatial organization of different biomolecules within bacterial organisms.

Raman imaging has the capability to provide unlabeled, spatially aware analysis of chemical components, with no a priori assumptions. Several lifestyle diseases such as nonalcoholic steatohepatitis (NASH) can appear in the liver as changes in the nature, abundance, and distribution of lipids, proteins, and other biomolecules and are detectable by Raman imaging. In order to identify which of these liver-associated changes occur as a direct result of the diet and which are secondary effects, we developed correlative imaging and analysis of diet and liver samples. Oleic acid was found to be a direct contributor to NASH liver composition, whereas protein and collagen distributions were found to be affected in a manner consistent with early fibrotic transformation, as a secondary consequence of the high-fat diet.

Genome maintenance comprises a group of complex and interrelated processes crucial for preserving and safeguarding genetic information within all organisms. Key aspects of genome maintenance involve DNA replication, transcription, recombination, and repair. Improper regulation of these processes could cause genetic changes, potentially leading to antibiotic resistance in bacterial populations. Due to the complexity of these processes, ensemble averaging studies may not provide the level of detail required to capture the full spectrum of molecular behaviors and dynamics of each individual biomolecule. Therefore, researchers have increasingly turned to single-molecule approaches, as these techniques allow for the direct observation and manipulation of individual biomolecules, and offer a level of detail that is unattainable with traditional ensemble methods. In this review, we provide an overview of recent in vitro and in vivo single-molecule imaging approaches employed to study the complex processes involved in prokaryotic genome maintenance. We will first highlight the principles of imaging techniques such as total internal reflection fluorescence microscopy and atomic force microscopy, primarily used for in vitro studies, and highly inclined and laminated optical sheet and super-resolution microscopy, mainly employed in in vivo studies. We then demonstrate how applying these single-molecule techniques has enabled the direct visualization of biological processes such as replication, transcription, DNA repair, and recombination in real time. Finally, we will showcase the results obtained from super-resolution microscopy approaches, which have provided unprecedented insights into the spatial organization of different biomolecules within bacterial organisms.

The quest for high spatial resolution in molecular identification is critical across various domains, including physiology, pathology, and pharmaceutical research. Super-resolution microscopy has made strides by surpassing the Abbe diffraction limit, but it relies on sophisticated equipment and is limited by the sample size to handle. Expansion microscopy, an emerging technique, has broadened the scope of subdiffraction imaging. It chemically preserves tissues at a large scale and physically enlarges them 4–20 times linearly, enabling super-resolution observation. This review begins by exploring the foundational concepts of tissue clearing and the latest methodologies in the field. It then delves into the core tenets of expansion microscopy, covering a range of protocols. The review spotlights advancements in enhancing resolution, improving labeling efficiency, and ensuring isotropic tissue expansion. Finally, the review offers insights into the prospective evolution of expansion microscopy. It emphasizes the potential role of machine learning in refining image quality and in the autonomous extraction of data, which could revolutionize the way we visualize and understand biological tissues.

Raman imaging has the capability to provide unlabeled, spatially aware analysis of chemical components, with no a priori assumptions. Several lifestyle diseases such as nonalcoholic steatohepatitis (NASH) can appear in the liver as changes in the nature, abundance, and distribution of lipids, proteins, and other biomolecules and are detectable by Raman imaging. In order to identify which of these liver-associated changes occur as a direct result of the diet and which are secondary effects, we developed correlative imaging and analysis of diet and liver samples. Oleic acid was found to be a direct contributor to NASH liver composition, whereas protein and collagen distributions were found to be affected in a manner consistent with early fibrotic transformation, as a secondary consequence of the high-fat diet.

The quest for high spatial resolution in molecular identification is critical across various domains, including physiology, pathology, and pharmaceutical research. Super-resolution microscopy has made strides by surpassing the Abbe diffraction limit, but it relies on sophisticated equipment and is limited by the sample size to handle. Expansion microscopy, an emerging technique, has broadened the scope of subdiffraction imaging. It chemically preserves tissues at a large scale and physically enlarges them 4-20 times linearly, enabling super-resolution observation. This review begins by exploring the foundational concepts of tissue clearing and the latest methodologies in the field. It then delves into the core tenets of expansion microscopy, covering a range of protocols. The review spotlights advancements in enhancing resolution, improving labeling efficiency, and ensuring isotropic tissue expansion. Finally, the review offers insights into the prospective evolution of expansion microscopy. It emphasizes the potential role of machine learning in refining image quality and in the autonomous extraction of data, which could revolutionize the way we visualize and understand biological tissues.

In the realm of nanomaterials, atomically precise quasi-molecular gold nanoclusters (AuNCs) play a prime role due to their unique, stable, and highly tunable optical properties. They are extensively structure-engineered for modulation of surface electronic states toward long wavelength photoluminescence, particularly in the NIR-II (1000 to 1700 nm) window. Contrast agents with NIR-II emission can potentially transform optical imaging in terms of higher spatial resolution, deeper tissue penetration, and reduced tissue autofluorescence. These advantages allow real-time imaging in living organisms for observing disease progression and treatment response. In this short review, we discuss origin of NIR-II emission in rationally designed AuNCs and their application toward high resolution imaging of vasculatures and hard and soft tissue structures for identification of pathological conditions such as stroke and injury. Further, recent employment of these AuNCs in the rapidly growing field of tumor theranostics is also summarized. Final remarks are provided on the scope for improvement in their optical properties and persisting challenges for clinical translation.