Low intensity near-infrared light promotes bone regeneration via circadian clock protein cryptochrome 1

Abstract

Bone regeneration remains a great clinical challenge. Low intensity near-infrared (NIR) light showed strong potential to promote tissue regeneration, offering a promising strategy for bone defect regeneration. However, the effect and underlying mechanism of NIR on bone regeneration remain unclear. We demonstrated that bone regeneration in the rat skull defect model was significantly accelerated with low-intensity NIR stimulation. In vitro studies showed that NIR stimulation could promote the osteoblast differentiation in bone mesenchymal stem cells (BMSCs) and MC3T3-E1 cells, which was associated with increased ubiquitination of the core circadian clock protein Cryptochrome 1 (CRY1) in the nucleus. We found that the reduction of CRY1 induced by NIR light activated the bone morphogenetic protein (BMP) signaling pathways, promoting SMAD1/5/9 phosphorylation and increasing the expression levels of Runx2 and Osterix. NIR light treatment may act through sodium voltage-gated channel Scn4a, which may be a potential responder of NIR light to accelerate bone regeneration. Together, these findings suggest that low-intensity NIR light may promote in situ bone regeneration in a CRY1-dependent manner, providing a novel, efficient and non-invasive strategy to promote bone regeneration for clinical bone defects.

NIR light‐facilitated bone tissue engineering

“…Periodic changes in the circadian system regulate osteoblast differentiation and further influence mineral deposition (Mcelderry et al, 2013). These phenomena motivate Peng et al to propose a novel potential mechanism for NIR to promote bone regeneration (Peng et al, 2022). In more detail, the inward flow of sodium ions caused by low‐intensity NIR light at 810 nm induced changes in osmotic pressure and pH inside and outside the cell.…”

LaOF:Yb3+, Er3+ Upconversion Nanophosphors Operating at Low Laser Powers for Nanothermometry Applications

“…Near-infrared (NIR)-pumped UCNPs are significantly studied for nanothermometry, especially in biomedical applications, due to the strong tissue penetration depth of the NIR light. , For practical applications, there are several factors that must be accounted for, besides the luminescence of the nanothermometer. These include the ease of availability, photostability, sensitivity, reusability, temperature range for effective operation, and the expenditure surrounding the fabrication and implementation of the device.…”