Extending the emission peak tail of indole cyanine for deep-near-infrared bioimaging.

We propose a novel strategy for tailoring the structure of fluorescent molecules to achieve emission at the tail end of the NIR-II window. The favorable spectroscopic properties and low cytotoxicity of YNs make them powerful tools for bioimaging. Notably, YN-4 exhibits a brightness 2.5 times greater than YN-3, 6 times that of IR-783, and 5 times that of ICG. This enhanced brightness enabled high-resolution imaging of mouse thoracic and abdominal cavities, tumor vasculature, and real-time monitoring of gastrointestinal motility using YN-4. Furthermore, covalent grafting of glucose onto the YN-Glu scaffold significantly improved tumor-targeting capability and facilitated tracking of glucose metabolism. This work aims to extend the application of fluorescent molecule imaging beyond the NIR-IIa window.

Polymer Microspheres Copolymerized with Deep Red Fluorescent Molecules as a Label for Lateral Flow Immunochromatography.

The development of fluorescently labeled microspheres is a critical aspect of advancing the technology of lateral flow immunochromatography (LFIA) for biological detection. Nevertheless, potential interference posed by the background fluorescence originating from the nitrocellulose (NC) membrane would significantly impact the sensitivity and accuracy of microsphere-based detection in LFIA. In this work, an attempt was made to extend the π-conjugated system and asymmetric structure of rhodamine fluorophore, resulting in the synthesis of dye molecules (RB2) incorporating double bonds, which can reach an absolute photoluminescence quantum yield (PLQY) of 30.01% in EtOH. Subsequently, carboxyl group functionalized fluorescent microspheres were prepared in a two-step copolymerization via soap-free emulsion polymerization. The obtained microspheres were characterized by scanning electron microscopy, transmission electron microscopy, DLS, Fourier transform infrared spectroscopy, ultraviolet spectrophotometry, and fluorescence spectrophotometry. The results showed that RB2 was successfully copolymerized into the microspheres, and the resulting microspheres had good dispersion and stability with high red fluorescence intensity (λabs ∼ 610 nm, λem ∼ 660 nm). Utilizing these microspheres, the resulting lateral flow immunoassay was successfully found to detect SARS-CoV-2 N protein with a detection limit of 2.5 pg/mL and the linear concentration spanning from 2.5 pg/mL to 10 ng/mL. The results confirm the effectiveness of the synthetic fluorescent microspheres as the label for LFIA.

A flavonoid salt probe for distinguishing between tumor and normal cells.

YH-2 represents an innovative, non-invasive fluorescent probe featuring a structure based on flavonoid onium salts. It is characterized by a well-suited Stokes shift and emits in the near-infrared (NIR) wavelength range. Its capacity to distinguish between HeLa cells, HepG2 cells, and LO2 cells is attributed to differential intracellular viscosity. Experimental results validate the heightened viscosity of organelles, such as the endoplasmic reticulum (ER), mitochondria and lysosomes in tumor cells compared to LO2 cells. Of paramount importance, YH-2 demonstrates the capability to swiftly image tumors within a mere 20 min following tail vein injection and this imaging ability can be sustained for an extended period of up to 5 h. This method offers a potential tumor diagnostic strategy in vivo.

Emergency surgery of intra-articular calcaneal fractures using sinus tarsi approach with modified reduction technique.

BACKGROUND: The purpose of this study was to evaluate emergency surgery of calcaneal fractures using the sinus tarsi approach (STA) with modified reduction technique in terms of complication rates, iconography results and functional outcome. METHODS: We evaluated the outcomes of 26 patients treated in an emergency using STA with modified reduction technique. For that, we assessed Böhler´s angle, Gissane angle, reduction of the calcaneal body, and posterior facet, the visual analog scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, complications, preoperative time, operative time, and in-hospital time. RESULTS: Recovery of calcaneal anatomy and articular surface were found at final follow-up. The mean Böhler´s angle at final follow-up were 30.68° ± 3.69°, of which was 15.02° ± 3.88° preoperatively (p < 0.001). The mean Gissane angle at final follow-up were 114.54° ± 11.16° of which was 88.86° ±10.96° preoperatively (p < 0.001). All cases had the varus/valgus angle of the tuber within 5 degrees. At the final follow-up, the mean AOFAS score was 89.23 ± 4.63, and the VAS score was 22.73 ± 6.5. CONCLUSIONS: Emergency surgery using STA with modified reduction technique is reliable, effective, and safe for treatment of calcaneal fractures. This technique can bring good clinical outcomes and a low rate of wound complications, reducing the in-hospital time, costs, and accelerating rehabilitation.

Rational design of a turn-on near-infrared fluorescence probe for the highly sensitive and selective monitoring of carboxylesterase 2 in living systems.

In vivo selective fluorescence imaging of carboxylesterase 2 (CES2) remains a great challenge because existing fluorescence probes can potentially suffer from interference by other hydrolases. In addition, some fluorescent probes that have been separately reported for measuring CES2 activity in vitro are affected by autofluorescence and absorption of the biological matrix due to their limited emission wavelength or short Stokes shift. Herein, based on the substrate preference and catalytic performance of CES2, a novel and NIR fluorescent probe was developed, in which a hemi-cyanine dye ester derivative was used as the basic fluorescent group. In the presence of CES2, the probe was hydrolyzed to expose the fluorophore CZX-OH (λabs ∼ 675 nm, λem ∼ 850 nm), which led to a notable red-shift in the fluorescence (∼175 nm) spectrum. Confocal imaging of cells and live mice demonstrated that the fluorescent signal of this probe was related to the real activities of CES2 in cancer cells. All these results will powerfully promote the screening of CES2 regulators and the analysis of CES2-related physiological and pathological processes.

Sinus Tarsi Approach With Percutaneous Screw Fixation for Intra-Articular Calcaneal Fractures.

The aim of this study was to evaluate the outcomes of surgical treatment of intra-articular calcaneal fractures by using the sinus tarsi approach combined with percutaneous medial reduction by leverage technique and percutaneous screw fixation. We assessed the outcomes of 29 patients treated using sinus tarsi approach with percutaneous screw fixation. All patients were evaluated both clinically and radiologically. The Böhler and Gissane angle were evaluated postoperatively using radiographs. During the median follow-up period of 27.0 ± 10.3 months, no cases with failure to reduce or displace hardware were detected. All cases achieved the restoration of a normal Böhler and Gissane angle. The median preoperative Böhler angle was 12.3° ± 2.5° while postoperatively it was 30.5° ± 5.7° (p < .01). The median preoperative Gissane angle was 98.1° ± 7.5°, which was 125.9° ± 3.6° postoperatively (p < .01). At the last follow-up, the median American Orthopedic Foot and Ankle Society hindfoot score was 87.7 ± 5.9, and the median Maryland foot score was 88.6 ± 5.9. Our technique for intra-articular calcaneal fractures can effectively correct calcaneal tuberosity outward displacement, medial wall overlapping, and the hindfoot varus deformity with less soft tissue damage. This technique is a good alternative for the treatment of calcaneal fractures, resulting in minimal soft tissue damage, few wound complications, and excellent radiological and clinical outcomes.

Articular calcaneal fractures: open or minimally invasive surgery, when the medial wall reduction is obtained percutaneously from the lateral side.

PURPOSE: The purpose of this study was to compare the clinical outcomes of intra-articular calcaneal fractures with medial column displacement treated with different surgical techniques, namely extensile lateral approach (ELA) or sinus tarsi approach (STA), combined with percutaneous medial reduction. METHODS: Ninety-six patients with intra-articular calcaneal fractures who were subjected to ELA or STA (45 in STA group and 51 in ELA group) were retrospectively assessed. Reduction of the posterior facet, calcaneal body, Böhler's angle, and Gissane's angle were evaluated. Clinical outcomes were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score and visual analog scale (VAS). The complications, time to surgery, operative time, and blood loss were also assessed. RESULTS: Incidence of wound complications, post-operative blood drainage, and time to the operation were significantly different between the two groups. There was no significant difference in the recovery of calcaneal anatomy and articular surface between the two groups. Similarly, no difference was detected in Böhler's and Gissane's angles between ELA and STA groups (P > 0.05). Finally, there was no difference in AOFAS and VAS scores between the two groups at the final follow-up (P > 0.05). CONCLUSION: STA resulted in favourable radiological and clinical results with fewer wound complications and a shorter waiting time when compared to ELA. The percutaneous medial reduction technique is effective in reducing medial column displacement.