Current Advances in Photoactive Agents for Cancer Imaging and Therapy

Abstract

Photoactive agents are promising complements for both early diagnosis and targeted treatment of cancer. The dual combination of diagnostics and therapeutics is known as theranostics. Photoactive theranostic agents are activated by a specific wavelength of light and emit another wavelength, which can be detected for imaging tumors, used to generate reactive oxygen species for ablating tumors, or both. Photodynamic therapy (PDT) combines photosensitizer (PS) accumulation and site-directed light irradiation for simultaneous imaging diagnostics and spatially targeted therapy. Although utilized since the early 1900s, advances in the fields of cancer biology, materials science, and nanomedicine have expanded photoactive agents to modern medical treatments. In this review we summarize the origins of PDT and the subsequent generations of PSs and analyze seminal research contributions that have provided insight into rational PS design, such as photophysics, modes of cell death, tumor-targeting mechanisms, and light dosing regimens. We highlight optimizable parameters that, with further exploration, can expand clinical applications of photoactive agents to revolutionize cancer diagnostics and treatment.

Surface-Fabrication of Fluorescent Hydroxyapatite for Cancer Cell Imaging and Bio-Printing Applications

“…Multifunctional nanoparticles are of great interest for new applications such as cell imaging, drug delivery and tumor therapy [ 1 , 2 , 3 , 4 , 5 ]. Increasing surface chemistry strategies are used to establish these nanosystems via surface modification, such as polymer surface coating and small molecule surface grafting [ 6 , 7 , 8 ].…”

Counterion Tuning of Near-Infrared Organic Salts Dictates Phototoxicity to Inhibit Tumor Growth

“…The lack of targeted therapy options remains a major problem for the effective treatment of many cancer types, and nonspecific chemotherapy leads to harsh side effects due to unintended toxicity in normal tissues . A promising solution is photodynamic therapy (PDT), which uses light-activated photosensitizers (PSs) to treat tumors by the generation of reactive oxygen species (ROS) upon photoexcitation. − PSs that absorb and emit in the near-infrared (NIR) range (650–1200 nm) display superior tissue penetration and reduced photodamage by avoiding visible light wavelengths (400–650 nm) absorbed by biological tissue components. − …”

Aspects of Antiviral Strategies Based on Different Phototherapy Approaches: Hit by the Light

“…Therefore, it is essential to develop new and innovative antiviral therapies. Phototherapy has proven its worth both in medical imaging and anticancer treatment [ 9 , 10 , 11 ]. Photodynamic (PDT) and photothermal (PTT) therapies require the use of photosensitizers (PS) and photothermal agents (PTA), respectively.…”

“…PS and PTA are molecules that can be photoactivated and if delivered to the organism, can cause targeted cellular damage. The major difference between PTT and PDT, is that PTT causes a temperature rise which can increase the tissue and cell damage ( Figure 1 a) [ 11 , 12 ]. In PDT, there are reactive oxygen species produced, which when accumulated, are detrimental to the target cell ( Figure 1 ).…”

“…Pharmaceuticals 2022, 15, x FOR PEER REVIEW 2 of 2 [11,12]. In PDT, there are reactive oxygen species produced, which when accumulated are detrimental to the target cell (Figure 1).…”