Near-Infrared Ratiometric Hemicyanine-Based pH Fluorescence Probe with Bone Targetability for Monitoring Bone Resorption

Abstract

Accurate detection of bone resorption is extremely important in the orthodontic treatment process as it can provide a basis for clinical treatment strategies. Recently, pH-responsive fluorescence probes have received tremendous attention in bone resorption monitoring owing to their high sensitivity, good specificity, and in situ and real-time detection capabilities, but there are still some shortcomings like the increase in the risk of osteonecrosis of the jaw by use of bisphosphonate as the bone-targeting moiety and the insufficient monitoring accuracy due to susceptibility to interference. Herein, we designed and synthesized a near-infrared ratiometric hemicyanine-based pH fluorescence probe (Hcy-Asp6) with fluorescence-imaging and pH-determining capabilities, and bone targetability for more reliably and safely monitoring the bone resorption in orthodontic treatment. In vitro optical performance tests of Hcy-Asp6 revealed that the probe had high sensitivity, excellent photostability, reversibility, and strong resistance to interference, and the probe suggested excellent bone-binding ability and biocompatibility in the bone-targeting evaluation and the cytotoxicity test. Furthermore, in vitro and in vivo bone resorption monitoring assays demonstrated that this probe can detect bone resorption by fluorescence imaging and quantitative monitoring of pH associated with the bone resorption. Thus, the results indicated that this probe possessing bone targetability and accurate bone resorption-monitoring capability has an extraordinarily great clinical potential to be employed for real-time monitoring of bone resorption in orthodontic treatment and could also serve as a reference in bone resorption monitoring for other bone resorption-related diseases.

One-step synthesis of a pH switched pyrene-based fluorescent probe for ratiometric detection of HS− in real water samples

“…42 By using rhodamine, Yang et al produced a pH based uorescent probe for selective detection of H 2 S in lysososmes. 43 In 2023, a benzo-hemicyanine based pH sensitive uorescent probe for monitoring bone resorption was reported by Y. Meng et al 44 However, these previously described probes have certain drawbacks, such as they can only detect pH between 4.0 and 7.4, must be synthesised using many steps, have less Stokes shi and are not reversible for specic reactive sulphur species. [45][46][47][48][49] Keeping this in mind, herein we constructed and synthesized a pH-switched pyrene-based uorescent probe for selective HS − sensing by a reversible reaction within 5 s. In the neutral conditions, probe Pyr remained colourless in visible light and displayed bright blue emission under a UV lamp.…”