There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Modern Raman Spectroscopy: A Practical Approach

Stereolithography is a solid freeform technique (SFF) that was introduced in the late 1980s Although many other techniques have been developed since then, stereolithography remains one of the most powerful and versatile of all SFF techniques It has the highest fabrication accuracy and an increasing number of materials that can be processed is becoming available In this paper we discuss the characteristic features of the stereolithography technique and compare it to other SFF techniques The biomedical applications of stereolithography are reviewed, as well as the biodegradable resin materials that have been developed for use with stereolithography Finally, an overview of the application of stereolithography in preparing porous structures for tissue engineering is given

A review on stereolithography and its applications in biomedical engineering

In the last two decades, Fourier Transform Infrared (FTIR) and Raman spectroscopies turn out to be valuable tools, capable of providing fingerprint-type information on the composition and structural conformation of specific molecular species. Vibrational spectroscopy’s multiple features, namely highly sensitive to changes at the molecular level, noninvasive, nondestructive, reagent-free, and waste-free analysis, illustrate the potential in biomedical field. In light of this, the current work features recent data and major trends in spectroscopic analyses going from in vivo measurements up to ex vivo extracted and processed materials. The ability to offer insights into the structural variations underpinning pathogenesis of diseases could provide a platform for disease diagnosis and therapy effectiveness evaluation as a future standard clinical tool.

Vibrational Spectroscopy Fingerprinting in Medicine: from Molecular to Clinical Practice

Compositional diversity is a fundamental property in cell populations. Single-cell analysis promises new insight into this cellular heterogeneity on the genomic, transcriptomic, proteomic, and metabolomic levels. Mass spectrometry (MS) is a label-free technique that enables the multiplexed analysis of proteins, peptides, lipids, and metabolites in individual cells. The abundances of these molecular classes are correlated with the physiological states and environmental responses of the cells. In this Minireview, we discuss recent advances in single-cell MS techniques with an emphasis on sampling and ionization methods developed for volume-limited samples. Strategies for sample treatment, separation methods, and data analysis require special considerations for single cells. Ongoing analytical challenges include subcellular heterogeneity, non-normal statistical distributions of cellular properties, and the need for high-throughput, high molecular coverage and minimal perturbation.

Single-Cell Mass Spectrometry Approaches to Explore Cellular Heterogeneity.

One of the most exciting developments in Raman spectroscopy in the last decade has been its application to cells and tissues for diagnostic and pharmaceutical applications, and in particular its use in the analysis of cellular dynamics. Raman spectroscopy is rapidly advancing as a cell imaging method that overcomes many of the limitations of current techniques and is earning its place as a routine tool in cell biology. In this review we focus on important developments in Raman spectroscopy that have evolved into the exciting technique of live-cell Raman microscopy and highlight some of the most recent and significant applications to cell biology.

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Raman spectroscopy: an evolving technique for live cell studies

Studying cells in a three‐dimensional (3D) environment has great potential in understanding cell behaviours such as morphology, proliferation, differentiation, and migration. Microengineered 3D cell scaffolds with precise defined geometries have offered a new approach to study cell behaviour and its interactions with scaffolds. The use of Raman spectroscopy to characterise biomolecules is a rapidly expanding area and has been implemented in numerous fields including pharmacology, microbiology, toxicology, and single‐cell studies. However, one area where it remains unexploited despite the vast potential of the technique is in the investigation of 3D cell scaffolds. A combination of Raman microscopy and chemometric approaches have employed to investigate the structure and biochemistry of nanofabricated scaffolds and a cell–scaffold complex. The 3D Raman mapping combined with the use of nanofabricated 3D scaffolds offers a unique opportunity to assess the influence of scaffold architecture on cell body and cell nuclei morphology and biochemistry. For the first time, we have cultured a human epithelial colorectal adenocarcinoma cell line on OrmoComp scaffolds and determined the structure and biochemistry of nanofabricated scaffolds and a cell–scaffold complex with the use of Raman microscopy combined with appropriate data analysis protocols. The results demonstrate the potential of 3D Raman mapping for identifying biochemical and physical variation within single cells as they grow and adhere to 3D scaffolds.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/jrs.5525

Single-cell Raman microscopy of microengineered cell scaffolds

Significance Diamond is the hardest material found in nature. Its applications range from abrasives and electronics to nanomedicine and laser technology. The common form of diamond is cubic. Yet, dense carbon materials formed by shock compression have been described as hexagonal diamond or lonsdaleite. This study provides a structural understanding of lonsdaleite and demonstrates the existence of bulk materials containing extensive regions of nanostructured diamond and graphene-like intergrowths called diaphites. The structural complexities found in Canyon Diablo iron meteorite diamonds occur in a wide range of carbonaceous materials, and their identification can place constraints on the pressure–temperature conditions experienced during an impact. The predicted advanced properties of such materials highlight their potential use in future engineering applications.

Rachael Smith

Papers

Raman spectroscopy: an evolving technique for live cell studies

Single-cell Raman microscopy of microengineered cell scaffolds

Shock-formed carbon materials with intergrown sp3- and sp2-bonded nanostructured units