Nanotransducers for Near‐Infrared Photoregulation in Biomedicine

Abstract

Photoregulation that utilizes light to remotely control biological events provides a precise way to decipher biology and innovate medicine; however, its potential has been limited by the shallow tissue penetration and/or phototoxicity of ultraviolet (UV)/visible light that are required to match the optical responses of endogenous photosensitive substances. Thereby, biologically friendly near-infrared (NIR) light with improved tissue penetration is desired for photoregulation. Since there are few endogenous biomolecules absorbing or emitting light in the NIR region, the development of molecular transducers is essential to convert NIR light into the cues for regulation of biological events. In this regard, optical nanomaterials able to convert NIR light into UV/visible light, heat or free radicals are competent for this task. This progress report summarizes the recent development of optical nanotransducers for NIR light-mediated photoregulation in medicine. The emerging applications including photoregulation of neural activity, gene expression, and visual systems as well as photochemical tissue bonding are highlighted along with the design principles of nanotransducers. Moreover, the current challenges and perspectives in this field are discussed.

Advanced Near‐Infrared Light for Monitoring and Modulating the Spatiotemporal Dynamics of Cell Functions in Living Systems

“…The emergence of a series of NIR light nanotransducers (such as UCNPs and AuNPs) that can convert NIR‐II light into visible/UV light or heat has made NIR‐II optogenetics possible. [ 5,42 ] However, several challenges are remained in fundamental biomedical research and clinical translation. First, the quantum yield of UCNPs and the photothermal conversion efficacy of Au nanomaterials are still relatively low.…”

“…[ 6–9 ] Currently, light has been extensively used in both fundamental research and clinical practice, such as cell signal sensing, enzyme activity monitoring, controlled drug release, visual regulation, neuromodulation, cancer diagnosis and treatment. [ 1,5,6,8,10 ]…”

“…[ 6,42,43 ] The NIR light can penetrate into the deep tissues (>1 cm) and can be directed to specific subcellular locations with micron spatial resolution, and can be turned on/off with a sub‐millisecond temporal resolution, thereby offering a noninvasive wireless tool to control specific cells in vivo. [ 5,6 ] Currently, optogenetic technologies using light‐sensitive ion channels, such as Channelrhodopsin (ChR), [ 44 ] Archaerhodopsin (Arch), [ 45 ] and Halorhodopsin (NpHR), [ 46 ] are the most powerful and popular tools for cell modulation. The development of NIR light‐sensitive proteins, such as the red‐shifted variant of channelrhodopsin (ReaChR) [ 47 ] and bacterial phytochromes (BphPs), [ 34 ] has made it possible to perform optogenetic research using red or NIR light.…”

“…Currently, a series of NIR light‐responsive nanomaterials have been developed for photoregulation in biomedicine, such as UCNPs, AuNPs, and organic semiconducting polymers. [ 5,42,48,26,117 ] Herein, the latest research progress of the development of novel photoregulation strategies and their applications in cancer therapy, regenerative medicine, and neuroscience were summarized and discussed ( Table 2 ).…”

Molecularly Engineered Macrophage‐Derived Exosomes with Inflammation Tropism and Intrinsic Heme Biosynthesis for Atherosclerosis Treatment

“…Generally,m acrophages are defined as two phenotypes: the pro-inflammatory M1 phenotype and the anti-inflammatory M2 phenotype. [14] We comparatively evaluated the secretion levels of anti-inflammatory cytokines (e.g.,I L-10, IL-1Ra, and TGF-b)a nd pro-inflammatory cytokines (e.g., interleukin-6 (IL-6), tumor necrosis factor (TNF-a), and metalloproteinase-10 (MMP-10)) in exosomes derived from pristine macrophages (M0 Exo), exosomes derived from M1polarized macrophages (M1 Exo) ( Figure S3), M2 Exo,a nd HAL@M2 Exo.Aspresented in Figure 2h,both M2 Exo and HAL@M2 Exo showed much higher levels of anti-inflammatory factors but much lower quantities of pro-inflammatory factors when compared with M0 Exo and M1 Exo,suggesting the potential anti-inflammatory response of M2 Exo.F or further verification, the inflammatory M1 cells were treated with M2 Exo or HAL@M2 Exo for 24 h, and then the phenotype transition of cells was evaluated by flow cytometry. We were glad to find that either M2 Exo or HAL@M2 Exo treatment could significantly induce the reprogramming of inflammatory M1 cells,asillustrated by the clearly increased expression of M2 biomarkers CD206 and CD163;meanwhile the dramatic decrease of M1 biomarkers CD80 and CD86 indicated the effective anti-inflammatory performance of M2 Exo and HAL@M2 Exo (Figure 2i).…”