Ninety percent of drugs fail during clinical trials, mainly due to lack of clinical efficacy. Recent developments in in vitro models such as 3D tumor heterospheroids have led to improvements in failure rates, but the relative lack of standardized evaluation methods for 3D cultures limits their utility in high-throughput screening. Optical coherence tomography (OCT) shows significant promise for high-throughput screening of 3D models; however, the optimal classification model and key image features for assessing drug efficacy in OCT images of spheroids has yet to be explored in detail. In this study, we investigate whether OCT combined with machine learning methods can be used to identify biomarkers of drug efficacy in 3D tumor spheroid models. We further compare the performance of two different models to determine the optimal configuration for accurate classification. Volumetric OCT images were acquired of co-cultured HT29 spheroids treated with 3 different concentrations of cisplatin. A two-dimensional multi-view ResNet model and a three-dimensional ResNet model were used to classify the images and to identify key image features associated with each group. Differences between spheroids treated with different concentrations of cisplatin are clearly visible in the OCT images. Our model was able to classify the images based on cisplatin concentration with 71.9% accuracy using the 2D multi-view model and 91.2% accuracy using the 3D model. Key features in the 3D model significantly improved the model accuracy. These results underscore the possibility that OCT could be used for high-throughput screening of drugs using 3D in vitro models and highlight key identifying features for further investigation.

Spatially offset OCT (SO-OCT) improves contrast at depth through a simple modification to a spectral domain OCT system. We achieve a tenfold CNR enhancement in phantoms and twofold improvement in ex vivo biological tissue.

While cancer characteristics can vary significantly across types, methods that distinguish malignant cells from normal ones hold promise by targeting shared cellular anomalies. Among these, morphological differences play a key role in driving the aggressive behavior and altered function typical of cancer cells. Detecting and analyzing such cells within complex, densely packed tissue environments requires advanced imaging techniques. Polarization-resolved fluorescence microscopy offers rich insights into cellular composition, molecular binding affinities, and structural organization, particularly in revealing biomolecular order and subcellular polarity loss. In this work, we study polarization-resolved two-photon excitation fluorescence tissue imaging microscopy in vitro to investigate ordered versus disordered chromatin organization within cell nuclei. We employ an innovative phasor map analysis to facilitate quick interpretation, using colorectal cancer identification and liquid crystal as a case study and baseline, respectively. Our method aims to identify cancer within tissue by adding polarimetric contrast to fluorescence due to the anisotropic feature of fluorescent molecular probes. Accordingly, the proposed phasor map provides a graphically transformed representation of polarization-based fluorescence imaging for histopathological tissue identification on a pixel-wise basis, facilitating comprehensive classification of diverse tissue samples. This study presents initial steps toward showing the potential for cancer identification and lays a foundation for future diagnostic strategies.

Neuropathy is a severe complication of diabetes that is difficult to diagnose at an early stage. Optical coherence tomography angiography may provide an indirect measurement of assessing nerve function.

The development of drug delivery systems demands close attention to product quality and consistency of quality attributes to guarantee reproducibility in fabrication, performance and therapeutic effectiveness. While some methods exist for monitoring in-line manufacturing, these methods are limited in terms of spatial resolution or depth penetration, which can lead to inconsistent characterization. Furthermore, conventional static characterization methods often lack the ability to monitor time-dependent changes within drug delivery systems. This limits their effectiveness in capturing dynamic processes such as swelling, disintegration, and drug release, underscoring the need for advanced techniques that offer reliable, high-resolution, and depth-specific insights into these mechanisms over time. Optical coherence tomography (OCT) is a non-invasive, high-resolution imaging technique which shows promise for comprehensive characterization of structural and dynamic characterization of drug delivery systems. In this study, we explore applications of OCT to structural and dynamic characterization of thin film drug delivery systems. We demonstrate that OCT can be used to non-destructively monitor the spatial variation of the refractive index and thickness of thin films, providing crucial feedback for quality control and ensuring standardized doses in individual film units. Further, we demonstrate that OCT can be used to monitor the dissolution dynamics, enabling characterization of time-controlled release mechanisms. These results suggest that OCT has the potential to enhance thin-film characterization by enabling more precise monitoring of critical quality attributes, which can contribute to improved manufacturing consistency and better control over the uniformity of the dose in each film unit.

Skin cancer is one of the most common types of cancer, frequently resulting from excessive exposure to ultraviolet radiation (UVR). Early detection and effective prevention of photodamage are important to mitigate the long-term risks of skin cancer. In this study, we investigate the use of optical coherence tomography (OCT) for assessing photodamage over time and the efficacy of photodamage prevention treatments non-invasively. Of the n = 81 hairless mice, 75 of them were exposed to ultraviolet radiation (UVR) three times per week to induce photodamage. Two different systemic photodamage prevention treatments were tested: nicotinamide mononucleotide (NMN) and polypodium leucotomos (PL). OCT images were acquired monthly on the back, side, and stomach of the mice over 7 months. Two OCT-derived metrics, skin thickness and the attenuation coefficient, μOCT , were quantified using a custom-developed algorithm to evaluate photodamage. Significant differences in skin thickness ( p = 0.038) and attenuation coefficient ( p <0.001) were observed between the UVR control group and the non-irradiated control group after 7 months at the back. At month 7, no significant difference was observed in the attenuation coefficient between the UVR control group and the UVR + PL group, however, a significant difference was observed between the UVR control group and the UVR + NMN group. Additionally, our OCT-derived skin thickness was well correlated with the skin thickness measured from histology, demonstrating a strong alignment with these invasive ground truth findings. Altogether, our results indicate that OCT could be a useful tool for non-invasive monitoring of photodamage in skin and for monitoring the efficacy of photodamage prevention treatments.

Significance:The use of tissue attenuation coefficients as biomarkers for disease detection is rising. However, especially for ex vivo studies, sample handling methods can notably impact tissue optical attenuation properties, and these effects have yet to be studied in detail. Aim:We aim to compare and evaluate common methods for sample handling and assess their impact on the optical attenuation and structural properties of ex vivo colon tissue. Approach:Six different handling methods were tested: Direct freezing at - 80 ° C , slow freezing in a cryobox with and without cryopreservation media, snap freezing in isopentane, formalin fixation, and fresh tissue stored directly in phosphate-buffered saline. All samples were imaged using optical coherence tomography; images were assessed qualitatively for morphological changes and quantitatively by extracting the tissue attenuation coefficient using the Lambert-Beer law. All handling methods were compared with representative histology (hematoxylin and eosin staining and periodic acid-Schiff staining). Results:All sample handling methods showed a significant difference in tissue attenuation and morphology relative to the fresh tissue ( p ≪ 0.0001 ), with frozen samples generally showing a lower attenuation coefficient, e.g., directly frozen ( 2.0 ± 1.0    mm - 1 ) compared with formalin-fixed ( 2.5 ± 1.3    mm - 1 ) and fresh tissue ( 2.5 ± 1.0    mm - 1 ). Formalin-fixed and snap frozen samples had the smallest effect size ( δ = 0.002 and - 0.09 , respectively). Macroscopic structural changes were also observed, including alterations to the epithelial layer and indications of goblet cell degradation for all methods but formalin fixation. Conclusions:Understanding the impact of sample handling methods is critical to the accurate interpretation of morphology-based analysis. In the case of fresh tissue being unavailable, formalin-fixed and snap frozen tissue samples yield the best alternative with negligible effect sizes for colon tissue.

Sample handling is an important consideration when aiming for replicating in vivo conditions ex vivo for the sake of validating imaging protocols and identifying biomarkers of disease. We tested five different handling methods: snap frozen in isopentane, directly frozen at -80 degrees C, slowly frozen in a cryobox with and without cryopreservation media, and formalin fixed. The samples were imaged using optical coherence tomography (OCT) for qualitative and quantitative validation based on morphological features and optical properties. All handling methods were compared to fresh tissue samples using OCT-derived optical properties and morphological features. The results indicate a significant difference in the optical attenuation coefficient as well as morphological differences between the five different methods and support the hypothesis that proper sample handling is crucial for obtaining translatable results.

Quantitative assessment of retinal microvasculature in optical coherence tomography angiography (OCTA) images is important for studying, diagnosing, monitoring, and guiding the treatment of ocular and systemic diseases. However, the OCTA user community lacks universal and transparent image analysis tools that can be applied to images from a range of OCTA instruments and provide reliable and consistent microvascular metrics from diverse datasets. We present a retinal extension to the OCTA Vascular Analyser (OCTAVA) that addresses the challenges of providing robust, easy-to-use, and transparent analysis of retinal OCTA images. OCTAVA is a user-friendly, open-source toolbox that can analyse retinal OCTA images from various instruments. The toolbox delivers seven microvascular metrics for the whole image or subregions and six metrics characterising the foveal avascular zone. We validate OCTAVA using images collected by four commercial OCTA instruments demonstrating robust performance across datasets from different instruments acquired at different sites from different study cohorts. We show that OCTAVA delivers values for retinal microvascular metrics comparable to the literature and reduces their variation between studies compared to their commercial equivalents. By making OCTAVA publicly available, we aim to expand standardised research and thereby improve the reproducibility of quantitative analysis of retinal microvascular imaging. Such improvements will help to better identify more reliable and sensitive biomarkers of ocular and systemic diseases.

High-throughput screening (HTS) three-dimensional (3D) tumor models are a promising approach for cancer drug discovery, as they more accurately replicate in vivo cell behavior than two-dimensional (2D) models. However, assessing and comparing current 3D models for drug efficacy remains essential, given the significant influence of cellular conditions on treatment response. To develop in vivo mimicking 3D models, we evaluated two HTS 3D models established in 96-well plates with 3D polycaprolactone (PCL) scaffolds fabricated using two distinct methods, resulting in scaffolds with either homogenous or non-homogenous fiber networks. These models, based on human HeLa cervical cancer cells and cancer-associated fibroblasts (CAFs) cultured as mono- or co-cultures within the 3D scaffolds, revealed that anticancer drug paclitaxel (PTX) exhibited consistently higher inhibitory concentration 50 (IC50) in 3D (≥ 1000nM) compared to 2D (≥ 100nM), indicating reduced toxicity on cells cultured in 3D. Interestingly, the toxicity of PTX was significantly lower on mini-tumors in non-homogenous 3D (IC50: 600 or 1000nM) than in homogenous 3D cultures (IC50 exceeding 1000nM). Microscopic studies revealed that the non-homogenous scaffolds closely resemble the tumor collagen network than their homogeneous counterpart. Both 3D scaffolds offer optimal pore size, facilitating efficient cell infiltration into the depth of 58.1 ± 1.2µm (homogenous) and 86.4 ± 9.8µm (non-homogenous) within 3D cultures. Cells cultured in the 3D non-homogenous systems exhibited drug treatment responses closer to in vivo conditions, highlighting the role of scaffold structure and design on cellular response to drug treatment. The PCL-based 3D models provide a robust, tunable, and efficient approach for the HTS of anti-cancer drugs compared Top of Formto conventional 2D systems.

In recent decades, late modernity has developed in the direction of ever greater inclusion of affective relationships. This has implications for the welfare professions’ working conditions and the content of the work. The article illustrates how theories about the development of the ‘society as a whole’ can qualify our understanding of some of the problems that currently characterize the welfare professions.

We investigate the accuracy of several models for extracting optical properties of tissue from optical coherence tomography images and assess their suitability for use in highly scattering media.