Optical study of chemotherapy efficiency in cancer treatment via intracellular structural disorder analysis using partial wave spectroscopy

Photonics probing of pup brain tissue and molecular-specific nuclear nanostructure alterations due to fetal alcoholism via light scattering/localization approaches

SIGNIFICANCE

Light is a good probe for studying the nanoscale-level structural or molecular-specific structural properties of brain cells/tissue due to stress, alcohol, or any other abnormalities. Chronic alcoholism during pregnancy, i.e., fetal alcoholism, being teratogenic, results in fetal alcohol syndrome, and other neurological disorders. Understanding the nano-to-submicron scale spatial structural properties of pup brain cells/tissues using light/photonic probes could provide a plethora of information in understanding the effects of fetal alcoholism.

AIM

Using both light scattering and light localization techniques to probe alterations in nano- to-submicron scale mass density or refractive index fluctuations in brain cells/tissues of mice pups, exposed to fetal alcoholism.

APPROACH

We use the mesoscopic physics-based dual spectroscopic imaging techniques, partial wave spectroscopy (PWS) and molecular-specific inverse participation ratio (IPR) using confocal imaging, to quantify structural alterations in brain tissues and chromatin/histone in brain cells, respectively, in 60 days postnatal mice pup brain, exposed to fetal alcoholism.

RESULTS

The finer focusing PWS analysis on tissues shows an increase in the degree of structural disorder strength in the pup brain tissues. Furthermore, results of the molecular-specific light localization IPR technique show an increase in the degree of spatial molecular mass density structural disorder in DNA and a decrease in the degree in histone.

CONCLUSIONS

In particular, we characterize the spatial pup brain structures from the molecular to tissue levels and address the plausible reasons for such as mass density fluctuations in fetal alcoholism.

Monitoring the Response of Skin Melanoma Cell Line (A375) to Treatment with Vemurafenib: A Pilot In Vitro Optical Spectroscopic Study

Objective: The aim of this study was to investigate the feasibility of optical spectroscopy as a nondestructive approach in monitoring the skin melanoma cancer cell response to treatment. Background: Owing to the growing trend of personalized medicine, monitoring the treatment response individually is particularly crucial for optimizing cancer therapy efficiency. In the past decade, optical sensing, using diffuse reflectance spectroscopy, has been used to improve the identification of cancerous lesions in various organs. Until now, surveys have mainly focused on the nondestructive application of optical sensing used to diagnose and discriminate normal and abnormal biomedical lesions or samples. Meanwhile, the response to the treatment might be monitored using these nondestructive technologies, thereby enabling further therapeutic modification. Methods: The human skin melanoma cell line (A375) donated from Switzerland (University Hospital Basel) was cultured. Vemurafenib (Zelboraf; Genentech/Roche, South San Francisco, CA) was used for cell treatments. The visible-near-infrared reflectance spectroscopy was conducted at different time intervals (before treatment, and at 1, 2, 7, and 14 days post-treatment for three drug doses 5, 25, and 75 μM) on cell plates using the portable CCD-based fiber optical spectrometer (USB2000; Ocean Optics). After data collection, the refractive index analysis for the fore-mentioned doses and days in one selected wavelength of 620 nm was examined using the previously developed computer program. Then, biological assays were selected as gold standard of cell death, apoptosis, and drug resistance gene expression. Results: There was a considerable decrease in the refractive index of cell samples in which biological assay confirmed cell death. Based on the flow cytometry data, a drug dose of 25 μM on day 7 seemed to induce necrosis. These findings show that spectroscopic findings strongly agree with concurrent biological studies and might lead to their use as an alternative method for monitoring treatment response to achieve more optimized cancer treatment. Conclusions: The findings show that reflectance spectroscopy, as a nondestructive real-time label-free way, is capable of providing quantitative information for treatment response determination that corresponds with biological assays.

Spectroscopic Study on Pseudomonas Aeruginosa Biofilm in the Presence of the Aptamer-DNA Scaffolded Silver Nanoclusters

We report the effectiveness of silver nanocluster (Ag-NC) against the biofilm of Pseudomonas aeruginosa (PA). Two DNA aptamers specific for PA and part of their sequences were chosen as templates for growing the Ag-NC. While circular dichroism (CD) studies determined the presence of secondary structures, UV/Vis absorption, and fluorescence spectroscopic studies confirmed the formation of the fluorescent Ag-NC on the DNA templates. Furthermore, mesoscopic physics-based partial wave spectroscopy (PWS) was used to analyze the backscattered light signal that can detect the degree of nanoscale mass density/refractive index fluctuations to identify the biofilm formation, comparatively among the different aptamers with respect to the control sample. The importance of the secondary structure of the aptamer DNA in targeting, successfully binding with the cells and delivering the Ag-NC, is evidenced by the decrease in disorder strength (L_d) of the Ag-NC treated samples compared to the untreated PA cells, which showed the abundance of higher L_d in the PWS studies. The higher L_d value attributed to the higher mass density fluctuations and the formation of biofilm. We envision this study to open a new avenue in using a powerful optical microscopic technique like PWS in detection, and DNA aptamer enclosed silver nanoclusters to prevent biofilms for opportunist pathogens like Pseudomonas aeruginosa.

Field cancerization in the understanding of parenchymal analysis of mammograms for breast cancer risk assessment

In recent years, mammographic image analysis has shown great potential for breast cancer risk assessment. The aim of risk assessment is to predict how likely a woman is to develop breast cancer in the future. Several studies suggest that computerized parenchymal analysis of mammograms can be utilized as an independent imaging biomarker of breast cancer. Parenchymal analysis consists of the quantitative assessment of visual texture patterns in mammograms to infer the level of risk. In spite of substantial evidence of the association between parenchymal patterns and breast cancer risk, its biological foundations remain poorly understood. In this work, we draw a hypothesis that links the field cancerization (FC) with breast cancer risk assessment based on the parenchymal analysis. In the literature, the FC is interpreted as a biochemical anomaly amplification in otherwise healthy cells due to the effect of pre-cancerous transformed cells in surrounding regions. Our hypothesis is that these biochemical anomaly amplifications change the cellular micro-environment which, in turn, alter tissue responses to X-ray radiation. As a result, it is reasonable to think that these changes influence the interaction of X-rays with parenchymal - the functional - breast tissue thus enabling cancer prediction by analyzing X-ray images of the breast. We believe that our hypothesis provides an actionable explanation as to how computerized parenchymal analysis of apparently normal mammograms can be successfully utilized for the stratification of breast cancer risk.

Optical detection of the structural properties of tumor tissue generated by xenografting of drug-sensitive and drug-resistant cancer cells using partial wave spectroscopy (PWS)

A mesoscopic physics-based optical imaging technique, partial wave spectroscopy (PWS), has been used for the detection of cancer by probing nanoscale structural alterations in cells/tissue. The development of drug-resistant cancer cells/tissues during chemotherapy is a major challenge in cancer treatment. In this paper, using a mouse model and PWS, the structural properties of tumor tissue grown in 3D structures by xenografting drug-resistant and drug-sensitive human prostate cancer cells having 2D structures, are studied. The results show that the 3D xenografted tissues maintain a similar hierarchy of the degree of structural disorder properties as that of the 2D original drug-sensitive and drug-resistant cells.

An optical study of drug resistance detection in endometrial cancer cells by dynamic and quantitative phase imaging

Platinum chemosensitivity detection plays a vital role during endometrial cancer treatment because chemotherapy responses have profound influences on patient's prognosis. Although several methods can be used to detect drug resistance characteristics, studies on detecting drug sensitivity based on dynamic and quantitative phase imaging of cancer cells are rare. In this study, digital holographic microscopy was applied to distinguish drug-resistant and nondrug-resistant endometrial cancer cells. Based on the reconstructed phase images, temporal evolutions of cell height (CH), cell projected area (CPA) and cell volume were quantitatively measured. The results show that change rates of CH and CPA were significantly different between drug-resistant and nondrug-resistant endometrial cancer cells. Furthermore, the results demonstrate that morphological characteristics have the potential to be utilized to distinguish the drug sensitivity of endometrial cancer cells, and it may provide new perspectives to establish optical methods to detect drug sensitivity and guide chemotherapy in endometrial cancer.