The Role of Photochemical Reactions in the Development of Advanced Soft Materials for Biomedical Applications

Abstract

In the biomedical field, many innovative materials to improve diagnosis and treatment of diseases are currently being developed. The ability to respond to different stimuli is one of the more interesting properties of such materials. Light, as one of the nature's elementary stimuli, offers an attractive and flexible stimulus for controlling the properties and functions of biomedical‐related materials. As such, photoresponsive systems have been increasingly pursued and finding applications in various biomedical settings, ranging from tissue engineering for the fabrication of bespoke tissue scaffolds to drug delivery, aims at manipulating treatment distribution inside the human body. Efforts have also been devoted to the development of highly efficient methods to control biological activity and bring us closer to mimicking impressive biological actuators. In this progress report, an overview of recent developments in the field is provided and current challenges discussed. Key strategies tailored to address specific issues are examined, offering useful perspectives for future designs.

Tailoring Iron Oxide Nanoparticles for Efficient Cellular Internalization and Endosomal Escape

“…As a result, this technology offers reduced phototoxic effect, which makes it a promising alternative for the implementation of PCI at clinical and experimental levels [ 317 , 318 , 319 ]. In fact, a recent report has demonstrated the biomedical application of NIR PCI through either direct irradiation or via local conversion with the aid of nanoparticles [ 320 ].…”

“…In this strategy, PS activation is directly performed by a NIR irradiation source, thus, intermediary molecules or additives are not required [ 320 ]. This technology has demonstrated efficient endosomal escape of multiple nano-release platforms in several biomedical applications such as drug delivery, cancer therapy, gene therapy, and imaging [ 320 , 321 ]. Recent reports have explored the combination of IONs with different PSs to enhance the performance of magnetically-guided and photoinduced delivery systems.…”

“…This strategy is based on the use of certain chemical substances that can transform low energy photons into high energy ones [ 320 ]. This phenomenon can be utilized to convert NIR light into UV or visible light radiation.…”

“…This phenomenon can be utilized to convert NIR light into UV or visible light radiation. The emitting radiation, namely, UV or visible, can be used to photo-activate PSs or for uncaging/cleaving nucleic acids or drugs [ 320 , 328 ]. The UV/Vis systems resulting from the conversion of NIR are commonly described as upconverted systems.…”

“…Photothermal therapy (PPT) is an alternative technique that relies on a photothermal transduction agent (PTA) to convert light into heat to increase the temperature in a localized manner ( Figure 10 A). This might lead to endocytic vesicle disruption and, consequently, to increased endosomal escape [ 309 , 320 ]. This approach makes use of a non-radiative relaxation pathway of photoexcitable molecules called internal conversion, where the light energy is transformed and dissipated as mechanical and thermal energy [ 320 ].…”