From Miniature Living Lasers To Optical Biopsies: The Bright Future Of Biophotonics

By John Oncea, Editor

Biophotonics is the study of how light interacts with biological matter. It has a wide range of applications in medicine, agriculture, environment, pharmaceutical, and biological sciences, using light as an energy source to conduct fundamental studies. Let’s shine a light on biophotonics and see what the future holds for it.

What happens when you take the Greek syllables bios, standing for life, and phos, standing for light? You get biophotonics, the technical term for all methodologies and technologies utilizing light over the whole spectrum from ultraviolet through the visible and the infrared to the terahertz region, and its interaction with any matter.

In the simplest of terms, biophotonics is the integration of four major technologies: biotechnology, lasers, photonics, and nanotechnology, notes News-Medical.Net. Other biophotonic technologies “include fluorescence, hyperspectral and diffuse-reflectance imaging, Raman spectroscopy, OCT (optical coherence tomography), and photodynamic therapy, as well as other light-induces treatment solutions,” according to NS Medical Devices.

See, simple. But not so fast.

“Beyond this definition, biophotonics is a scientific discipline of remarkable societal importance,” writes Wiley Online Library. “For hundreds of years, researchers have utilized light-based systems to explore the biological basics of life. After the invention of the light microscope dating back to the seventeenth century and the systematic improvements introduced by Carl Zeiss, Ernst Abbe, and Otto Schott in Jena in the nineteenth century, it became an essential tool in the life sciences and medicine and had a crucial influence on the work of biologists of this time, such as Ernst Haeckel.”

Over time, the significance of observing cellular structures has become even more important. With the advancement of ultrahigh resolving microscopes, we can now study structures that are smaller than 20 nm and analyze their functions.

This technology has allowed us to understand the root cause of various diseases. Additionally, we can now utilize photonic technologies to both diagnose and treat diseases, which has improved healthcare outcomes. “For example,” Wiley Online Library writes, “laser scalpels have become routine tools which reduce the expense of many surgeries, sometimes even down to an ambulant intervention (keyhole surgery).”

Recent advances in photonic technologies such as fluorescence endoscopy and photodynamic therapy (PDT) have made it possible to identify certain types of cancer at an earlier stage and treat them more effectively and safely than was possible in previous years.

In the field of ophthalmology, optical coherence tomography (OCT) has emerged as the standard method for detecting structural changes in the eye in three dimensions, allowing for the generation of high-resolution 3D images of the retina. This has facilitated the diagnosis of common eye diseases such as glaucoma and macular degeneration.

Biophotonics In Action

So, what’s to be gained by using various types of lasers guided with precision to deliver light to specific locations within biological systems, then capturing and measuring the light signals emitted or reflected from biological samples?

Diagnostic biophotonics can detect diseases in their early stages before symptoms appear and novel endoscopic biophotonic diagnostic technologies can non-invasively detect the interior of a hollow organ or cavity. Biophotonics can obtain biochemical information about tissue in real time and biophotonic probes can be used for cellular tagging and tracking, diagnostics, intracellular sensing, and novel imaging. Finally, biophotonic techniques combined with nanomedicine could lead to localized surgery to disrupt or remove tumors without invasiveness.

Other benefits derived from the use of biophotonics include:

• Fundamental biomedical research: Cell biology, molecular biology: understanding of life processes, and also the origin and genesis of diseases, on a cellular and molecular level. Pharmacological research: Drug development, for example, target evaluation, high-throughput screening (HTS) and/or high-content screening (HCS) of drug candidates, and drug delivery.
• Laboratory tests, point of care (POC) diagnostics: Analysis of body liquids, for example, in allergology, immunology, hematology, cardiology, epidemiology, endocrinology, medical microbiology; and Optical sensing, for example, optical oximetry.
• Clinical diagnostics, therapy control, and therapy: Medical disciplines from cardiology to oncology to urology use biophotonics to image atherosclerotic plaques; detect, stage, and grade tumors, and remove benign hyperplasia, strictures, and renal calculi.
• Regenerative medicine: Stem cell research, tissue engineering, transfection of genetic material.
• Environmental monitoring, and food safety: On-site testing and monitoring of harmful compounds in air, water, and food, for example, pathogens, fine dust, pollen, and chemicals.
• Process control: Controlling composition and quality of pharmaceuticals, nutrition, and cosmetics.
• Security applications: Detection of harmful biological and chemical substances and weapons.

What Lies Ahead?

Over the past few years, we have witnessed a remarkable advancement in biotechnology which has enabled us to gain a deeper understanding of the behavior of living organisms, their internal structure, and their response to various chemical compounds and external agents. This information is highly valuable in the development of new products and in enhancing the performance of existing healthcare solutions and medical devices.

“The worldwide biophotonics market is expected to witness significant growth in the future, due to the rising old age population, along with the increasing incidence of chronic diseases,” writes 360 Research Report Insights. “Other factors include the increasing use of biophotonics in cell and tissue diagnostics, the emergence of nanotechnology in biophotonics, and the development of novel photoacoustic tomography (PAT) systems.”

Also responsible for the increasing use of biophotonics are recent innovations in material science, biomedical optics, processing technology, and nanotechnology that have led to the development of increasingly sophisticated technologies like cellular-scale, wireless microdevices that can be remotely controlled and integrated into living organisms. These devices, according to the National Library of Medicine (NLM), may yield futuristic applications such as miniature living lasers, wireless remotely controlled implantable devices, and cellular optoelectronics – all of which have the potential for novel imaging, diagnostic, and therapeutic applications.

“Biological microlasers offer the advantages of better performance at deep tissue depth due to their high sensitivity, bright narrowband emission, single-cell specificity, high signal-to-noise ratio, low background autofluorescence, and minimum scattering interferences,” NLM writes. “Thus, they have shown to be potential in imaging, sensing, in vivo cell tagging as well as for long-term tracking to gather information from biological processes occurring at the molecular to subcellular and cellular level, as well as in small animals.”

Biological microlasers have the potential to revolutionize our understanding of crucial biological processes such as cancer metastasis, neuronal network development, wound healing, and immune response. In the field of optoelectronic applications, future designs in optogenetics will enable bioelectric signal-based sensing and power control for the simultaneous stimulation of multiple deep neural targets outside the brain, spinal cord, and peripheral nerve. This approach holds immense promise in treating several neurodegenerative diseases.

NLM concludes, “Soon, it is being envisaged that integration of self-powered and machine learning technology in portable wearable optoelectronic systems will allow in vivo ‘recognition,’ ‘think,’ ‘analyze,’ ‘decide,’ and ‘control’ abilities to assist in smart diagnosis, drug transport followed by controlled drug delivery.

“Fast-growing research and advancement in technology will surely increase the integration of these light-based functionalities in patients for early detection and real-time diagnosis of several diseases and designing of personalized treatment with better therapeutic outcomes. It's exciting to see how the biophotonics field will evolve in the future as a smart human health monitoring and therapeutic strategy.”