Morphological measurement of living cells in methanol with digital holographic microscopy

Holography applications toward medical field: An overview

Purpose:

3D Holography is a commercially available, disruptive innovation, which can be customised as per the requirements and is supporting Industry 4.0. The purpose of this paper is to study the potential applications of 3D holography in the medical field. This paper explores the concept of holography and its significant benefits in the medical field.

Methods:

The paper is derived through the study of various research papers on Holography and its applications in the medical field. The study tries to identify the direction of research &development and see how this innovative technology can be used effectively for better treatment of patients.

Results:

Holography uses digital imaging inputs and provides an extensive visualisation of the data for training doctors, surgeons and students. Holography converts information about the body into a digital format and has the potential to inform, promote and entertain the medical students and doctors. However, it needs a large amount of space for data storage and extensive software support for analysis and skills for customising. This technology seems good to solve a variety of medical issues by storing and using patient data in developing 3D holograms, which are useful to assist successful treatment and surgery. It seems useful in providing flexible solutions in the area of medical research. Finally, the paper identifies 13 significant applications of this technology in the medical field and discusses them appropriately.

Conclusion:

The paper explores holographic applications in medical research due to its extensive capability of image processing. Holographic images are non-contact 3D images having a large field of depth. A physician can now zoom the holographic image for a better view of the medical part. This innovative technology can create advancements in the diagnosis and treatment process, which can improve medical practice. It helps in quick detection of problems in various organs like brain, heart, liver, kidney etc. By using this technology, medical practitioners can see colourful organs at multiple angles with better accuracy. It opens up an innovative way of planning, testing of procedures and diagnosis. With technological developments, compact hardware and software are now available to help medical research and related applications.

Quantitative evaluation of morphological changes in activated platelets in vitro using digital holographic microscopy

Platelet activation and aggregation have been conventionally evaluated using an aggregometer. However, this method is suitable for short-term but not long-term quantitative evaluation of platelet aggregation, morphological changes, and/or adhesion to specific materials. The recently developed digital holographic microscopy (DHM) has enabled the quantitative evaluation of cell size and morphology without labeling or destruction. Thus, we aim to validate its applicability in quantitatively evaluating changes in cell morphology, especially in the aggregation and spreading of activated platelets, thus modifying typical image analysis procedures to suit aggregated platelets. Freshly prepared platelet-rich plasma was washed with phosphate-buffered saline and treated with 0.1% CaCl₂. Platelets were then fixed and subjected to DHM, scanning electron microscopy (SEM), atomic force microscopy, optical microscopy, and flow cytometry (FCM). Tightly aggregated platelets were identified as single cells. Data obtained from time-course experiments were plotted two-dimensionally according to the average optical thickness versus attachment area and divided into four regions. The majority of the control platelets, which supposedly contained small and round platelets, were distributed in the lower left region. As activation time increased, however, this population dispersed toward the upper right region. The distribution shift demonstrated by DHM was essentially consistent with data obtained from SEM and FCM. Therefore, DHM was validated as a promising device for testing platelet function given that it allows for the quantitative evaluation of activation-dependent morphological changes in platelets. DHM technology will be applicable to the quality assurance of platelet concentrates, as well as diagnosis and drug discovery related to platelet functions.

Interfacing antibody-based microarrays and digital holography enables label-free detection for loss of cell volume

Background:

We introduce the combination of digital holographic microscopy (DHM) and antibody microarrays as a powerful tool to measure morphological changes in specifically antibody-captured cells. The aim of the study was to develop DHM for analysis of cell death of etoposide-treated suspension cells.

Results/methodology:

We demonstrate that the cell number, mean area, thickness and volume were noninvasively measured by using DHM. The cell number was stable over time, but the two cell lines showed changes of cell area and cell irregularity after treatment. The cell volume in etoposide-treated cells was decreased, whereas untreated cells showed stable volume.

Conclusion:

Our results provide proof of concept for using DHM combined with antibody-based microarray technology for detecting morphological changes in captured cells.

We use an innovative technique that combines digital holographic microscopy and the capture of cells with antibody microarrays as a powerful tool to measure cellular morphological changes. With this technique, the cells can be noninvasively viewed in 3D over time. We obtain results showing changes in cellular parameters including cell area, thickness and volume of the captured cells after treatment with the cell death-inducing drug etoposide. The cell volume in etoposide-treated cells showed a decrease, while untreated cells remained stable. Digital holographic microscopy combined with antibody microarray technology can be a future method for detecting morphological changes in treated cancer cells.

Quantitative stain-free and continuous multimodal monitoring of wound healing in vitro with digital holographic microscopy

Impaired epithelial wound healing has significant pathophysiological implications in several conditions including gastrointestinal ulcers, anastomotic leakage and venous or diabetic skin ulcers. Promising drug candidates for accelerating wound closure are commonly evaluated in in vitro wound assays. However, staining procedures and discontinuous monitoring are major drawbacks hampering accurate assessment of wound assays. We therefore investigated digital holographic microscopy (DHM) to appropriately monitor wound healing in vitro and secondly, to provide multimodal quantitative information on morphological and functional cell alterations as well as on motility changes upon cytokine stimulation. Wound closure as reflected by proliferation and migration of Caco-2 cells in wound healing assays was studied and assessed in time-lapse series for 40 h in the presence of stimulating epidermal growth factor (EGF) and inhibiting mitomycin c. Therefore, digital holograms were recorded continuously every thirty minutes. Morphological changes including cell thickness, dry mass and tissue density were analyzed by data from quantitative digital holographic phase microscopy. Stimulation of Caco-2 cells with EGF or mitomycin c resulted in significant morphological changes during wound healing compared to control cells. In conclusion, DHM allows accurate, stain-free and continuous multimodal quantitative monitoring of wound healing in vitro and could be a promising new technique for assessment of wound healing.