A thiol-triggered croconaine-chromene integration to induce ferroptosis and photothermal synergistic efficient tumor ablation.

Theranostic probes, combining diagnostic and treatment capabilities, have emerged as promising tools in tumor precision medicine. However, existing probes with constant fluorescence and photothermal activity can result in low signal-to-background ratios and phototoxicity. In this study, we introduced CM-Croc, a novel probe comprised of chromene and croconaine, selectively triggered by thiol. CM-Croc exhibited turn-on fluorescence and released croconaine for photothermal therapy. The croconaine moiety possesses high photothermal conversion efficiency up to 55%. Besides, it demonstrated potent activity against various cancer cell lines at low micromolar concentrations, including drug-resistant variants, through enhanced photothermal therapy combined with the ferroptosis effect. What's more, CM-Croc was proved to inhibit the activity of GPX4 to induce ferroptosis. Finally, CM-Croc was demonstrated to be the first croconaine-derived SOP, which targeted tumors and significantly inhibited tumor growth in vivo following intravenous administration with irradiation. This study showed CM-Croc's potential for enhancing tumor precision medicine.

Biomedical-Optical-Window Tailored Cyanines for Steerable Inflammatory Bowel Disease Theranostic.

Tailored photophysical properties and chemical activity is the ultimate pursuit of functional dyes for in vivo biomedical theranostics. In this work, the independent regulation of the absorption and fluorescence emission wavelengths of heptamethine cyanines is reported. These dyes retain near-infrared fluorescence emission (except a nitro-modified dye) while feature variable absorption wavelengths ranging from 590 to 860 nm. This enables to obtain customized functional dyes that meet the excitation and fluorescence wavelength requirements defined by the optical properties of tissues for in vivo biomedical applications. Typically, a nitro-modified photothermal active derivative Cy-Mu-7-9 is used, which features strong absorption at 810 nm in PBS, a wavelength that balanced the tissue penetration depth and non-specific photothermal effect, to realize non-destructive inflammatory bowel disease (IBD) therapy via photothermal induced up-regulation of heat shock protein 70 in the intestinal epithelial cells. The corresponding amino-modified dye Cy-Mu-7-9-NH2, which can be formed in health enteric cavity by Cy-Mu-7-9 after oral administration, is a fluorescence compound with the emission of 800 nm in PBS. Based on the IBD sensitive transformation of Cy-Mu-7-9 and Cy-Mu-7-9-NH2, in vivo IBD theranostic and therapeutic effect evaluation is realized via the synergy of fluorescence imaging and photothermal therapy for the first time.

Fluorimetric Tool to Discriminate Glomerular and Tubular Injuries In Vivo.

The etiology and pathological complexity of acute kidney injury (AKI) pose great challenges for early diagnosis, typing, and personalized treatment. It is an important reason for poor prognosis and high mortality of AKI. In order to provide a relatively noninvasive diagnostic and typing method for AKI, we proposed the pathological changes of albumin permeability after glomerular injury and reabsorption efficiency after tubular injury as potential entry points. Thus, a renal tubule labeling fluorescent dye which features albumin concentration-related fluorescence intensity was used to fit these pathological changes. Utilizing this fluorescence assay, we realized urinary tract obstruction imaging as early as 12 h after morbidity. For glomerular and tubular injury discrimination, compared to a healthy control, membranous nephropathy as a representative glomerular injury resulted in enhanced fluorescence intensity of the kidney due to increased albumin penetration, while renal tubular injury caused insufficient dye reabsorption to exhibit weakened fluorescence intensity. The significant differences demonstrated the feasibility of this approach for fluorescence imaging-based AKI typing in vivo.

Notch Signaling Hydrogels Enable Rapid Vascularization and Promote Dental Pulp Tissue Regeneration.

Successful dental pulp regeneration is closely associated with rapid revascularization and angiogenesis, processes driven by the Jagged1(JAG1)/Notch signaling pathway. However, soluble Notch ligands have proven ineffective in activating this pathway. To overcome this limitation, a Notch signaling hydrogel is developed by indirectly immobilizing JAG1, aimed at precisely directing the regeneration of vascularized pulp tissue. This hydrogel displays favorable mechanical properties and biocompatibility. Cultivating dental pulp stem cells (DPSCs) and endothelial cells (ECs) on this hydrogel significantly upregulate Notch target genes and key proangiogenic markers expression. Three-dimensional (3D) culture assays demonstrate Notch signaling hydrogels improve effectiveness by facilitating encapsulated cell differentiation, enhancing their paracrine functions, and promoting capillary lumen formation. Furthermore, it effectively communicates with the Wnt signaling pathway, creating an odontoinductive microenvironment for pulp-dentin complex formation. In vivo studies show that short-term transplantation of the Notch signaling hydrogel accelerates angiogenesis, stabilizes capillary-like structures, and improves cell survival. Long-term transplantation further confirms its capability to promote the formation of pulp-like tissues rich in blood vessels and peripheral nerve-like structures. In conclusion, this study introduces a feasible and effective hydrogel tailored to specifically regulate the JAG1/Notch signaling pathway, showing potential in advancing regenerative strategies for dental pulp tissue.

Sustained free chlorine-releasing polydimethylsiloxane/Ca(ClO)2 materials with long-lasting disinfection efficacy.

A novel sustained chlorine-releasing polydimethylsiloxane/Ca(ClO)2 (PDMS/Ca(ClO)2) material was fabricated by encapsulating Ca(ClO)2 in a PDMS matrix due to its high hydrophobicity and high chemical stability, which showed immediate-responsive and long-lasting antibacterial capabilities in aqueous conditions. Free chlorine could be released from the PDMS/Ca(ClO)2 after immersion in water for 2 min and could also be sustainedly released for 2 weeks, while the released concentration is negatively related to the duration time and positively with the initial Ca(ClO)2 contents. Additionally, Ca(ClO)2 powder as a filler significantly affects the crosslinking and pore size of PDMS. The PDMS/Ca(ClO)2 materials exhibited enduring antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in both planktonic and multispecies-biofilm status. It is expected that this PDMS/Ca(ClO)2 material and its similar composite would be promising candidates for wide sustainable disinfection applications in biomedical and industrial fields.

Photoactivation Inducing Multifunctional Coupling of Fluorophore for Efficient Tumor Therapy In Situ.

Photoactivatable molecules, with high-precision spatialtemporal control, have largely promoted bioimaging and phototherapy applications of fluorescent dyes. Here, the first photoactivatable sensor (BI) is described that can be triggered by broad excitation light (405-660 nm), which further undergoes intersystem crossing and H-atom transfer processes to forming superoxide anion radicals (O2 -•) and carbon radicals. Particularly, the photoinduced gain of carbon-centered radicals (BI•) allows for radical-radical coupling to afford the combined crosslink product (BI─BI), which would be oxidized in the presence of O2 -• to produce an extended conjugate system with near infrared emission (820 nm). Besides, the photochemically generated product (Cy─BI) possesses ultra-high photothermal conversion efficiency up to 90.9%, which optimized phototherapy potential. What's more, Western Blot assay reveals that both BI and the photoproduct Cy─BI can efficiently inhibit the expression of CHK1, and the irradiation of BI and Cy─BI further induces apoptosis and ultimately enhances the phototherapeutic effects. Thus, the combination of cell cycle block inducing apoptosis, photodynamic therapy and photothermal therapy treatments significantly suppress solid tumor in vivo antitumor efficacy explorations. This is a novel finding in developing photoactivatable molecules, as well as the broad applicability of photoimaging and phototherapy in tumor-related areas.

Development of Human Serum Albumin Fluorescent Probes in Detection, Imaging, and Disease Therapy.

Human serum albumin (HSA) acts as a repository and transporter of substances in the blood. An abnormal concentration may indicate the occurrence of liver- and kidney-related diseases, which has attracted people to investigate the precise quantification of HSA in body fluids. Fluorescent probes can combine with HSA covalently or noncovalently to quantify HSA in urine and plasma. Moreover, probes combined with HSA can improve its photophysical properties; probe-HSA has been applied in real-time monitoring and photothermal and photodynamic therapy in vivo. This Review will introduce fluorescent probes for quantitative HSA according to the three reaction mechanisms of spatial structure, enzymatic reaction, and self-assembly and systematically introduce the application of probes combined with HSA in disease imaging and phototherapy. It will help develop multifunctional applications for HSA probes and provide assistance in the early diagnosis and treatment of diseases.

Cellular Senescence in Craniofacial Tissue Regeneration: Inducers, Biomarkers, and Interventions.

Craniofacial defects and dental tissue loss have significant negative impacts on the structure and function of jaws and face, often resulting in psychological issues in patients, emphasizing the urgent need for effective craniofacial tissue reconstruction. Unfortunately, natural regeneration of these tissues is limited. Dental-derived mesenchymal stem cells (MSCs) have emerged as a promising resource for tissue engineering-based therapeutic approaches. However, the clinical outcomes of MSC-based transplantation have not met expectations due to various complex reasons, and cellular senescence is recognized as one of the potential mechanisms contributing to the suboptimal results. The quality of MSC decreases during large-scale in vitro expansion, and it is also influenced by the age and the health status of donors. To address these challenges, extensive efforts have been made to developing strategies to combat senescence in tissue engineering, leveraging on current knowledge of underlying mechanisms. This review aims to elucidate the impact of cell senescence in craniofacial and dental regeneration and provides an overview of state-of-the-art antisenescence strategies. We first discuss the potential factors that trigger cell senescence in craniofacial tissue engineering. Then we describe senescence biomarkers, monitoring methods for senescent MSCs, and their underlying molecular mechanisms. The primary focus of this review is on current strategies to inhibit and alleviate cell senescence in tissue engineering. We summarize the strategies concerning the prevention of cell senescence, senolysis, modulation of the senescent associated secretory phenotype, and reversal of senescent MSCs, offering promising opportunities to overcome the challenges associated with cell senescence in craniofacial tissue engineering.

An ICT-switched fluorescent probe for visualizing lipid and HClO in lipid droplets during ferroptosis.

Herein, we have designed and synthesized a fluorescent probe, LDs-ClO, which can detect hypochlorous acid and lipid accumulation simultaneously in lipid droplets of live RAW 264.7 cells. Cell ferroptosis was discovered to lead to an increase in HClO levels, and to possibly further stimulate accumulation of lipid. We expect the results of this work with LDs-ClO to promote the study of physiological and pathological processes related to lipid droplets and hypochlorite.

A summary of calixarene-based fluorescent sensors developed during the past five years.

Calixarenes are "chalice like" phenol-based macrocycles that are one of the most fascinating studied scaffolds in supramolecular chemistry. Their preorganized nonpolar cavities and ion binding sites, and their well-defined conformations all lay important foundations for forming host-guest complexes. Conjugation of calixarene scaffolds with various fluorophores at either upper or lower rims has led to the development of smart fluorescent probes for inorganic molecules or ions, aliphatic or aromatic compounds, biomolecules, temperature and hypoxia, even multi-component traditional Chinese medicine (TCM). Moreover, significant advancements have been made for biological applications. This review critically summarizes the recent advances made in these areas.

Personalized 3D-Printed Scaffolds with Multiple Bioactivities for Bioroot Regeneration.

Recent advances in 3D printing offer a prospective avenue for producing transplantable human tissues with complex geometries; however, the appropriate 3D-printed scaffolds possessing the biological compatibility for tooth regeneration remain unidentified. This study proposes a personalized scaffold of multiple bioactivities, including induction of stem cell proliferation and differentiation, biomimetic mineralization, and angiogenesis. A brand-new bioink system comprising a biocompatible and biodegradable polymer is developed and reinforced with extracellular matrix generated from dentin tissue (treated dentin matrix, TDM). Adding TDM optimizes physical properties including microstructure, hydrophilicity, and mechanical strength of the scaffolds. Proteomics analysis reveals that the released proteins of the 3D-printed TDM scaffolds relate to multiple biological processes and interact closely with each other. Additionally, 3D-printed TDM scaffolds establish a favorable microenvironment for cell attachment, proliferation, and differentiation in vitro. The 3D-printed TDM scaffolds are proangiogenic and facilitate whole-thickness vascularization of the graft in a subcutaneous model. Notably, the personalized TDM scaffold combined with dental follicle cells mimics the anatomy and physiology of the native tooth root three months after in situ transplantation in beagles. The remarkable in vitro and in vivo outcomes suggest that the 3D-printed TDM scaffolds have multiple bioactivities and immense clinical potential for tooth-loss therapy.

A nucleophilic addition-elimination based ratiometric fluorescent probe for monitoring N2H4 in biological systems and actual samples.

Hydrazine (N2H4) is an important reagent in the field of fine chemical engineering. However, its accumulation in the environment and food chain could pose a great threat to food safety and human health. Therefore, designing a fluorescent probe with good cell penetration and high selectivity and sensitivity to detect N2H4 in actual samples and in vivo is a meaningful project. Herein, due to the nucleophilicity of hydrazine, we utilized naphthalimide as the fluorescence chromophore and pyrone as the recognition site to achieve the ratiometric detection of hydrazine by ring opening. In addition, we introduced the ester to improve the lipid solubility of the probe, which allowed the probe to better penetrate the cell membrane to realize the fluorescent imaging of probes in cells. Meanwhile, to our delight, the probe showed high selectivity and sensitivity to N2H4 in the test system, so we further applied the probe in water samples and food, in vitro and in vivo.

A near-infrared fluorescent probe for in situ imaging of SO2 flux in drug-induced liver injury.

Sulfur dioxide (SO2) has been widely applied as an important additive in various foods and drugs due to its antioxidant, antiseptic and bleaching properties. SO2 in living organisms plays a key biological role as an antioxidant in a variety of life activities. However, abnormal levels of SO2 in both food and living organisms could cause harm and even serious illness, such as diseases related to the respiratory and cardiovascular systems and cancers. Therefore, it is of great practical significance to accurately determine the level of SO2 in food and organisms. In this work, we synthesized a novel near-infrared ratiometric fluorescent probe (NTO) using xanthene and benzopyran as the matrix for the detection of SO2. NTO demonstrates a rapid response (within 8 s), high selectivity, excellent sensitivity (LOD = 3.64 µM) and a long emission wavelength (800 nm), which could be applied to SO2 monitoring in a complex environment. NTO showed a high recovery (90%-110%) of SO2 in food samples such as beer and rock sugar. The results of HeLa cell experiments indicate that NTO has excellent fluorescence labeling ability for SO2 in endoexogenous-sulfide metabolism. In addition, we applied it to mice with acetaminophen (APAP)-induced acute liver injury and observed changes in SO2 during liver injury. Based on these results, we believe that this will provide a convenient visual tool for the detection of the SO2 content in food safety and biomedicine.

Dental Follicle Stem Cells Promote Periodontal Regeneration through Periostin-Mediated Macrophage Infiltration and Reprogramming in an Inflammatory Microenvironment.

Dental follicle stem cells (DFSCs) have been verified to promote periodontal regeneration in an inflammatory microenvironment. When coping with inflammatory stimulation, DFSCs highly express periostin, a bioactive molecule closely related to periodontal homeostasis. It is worth exploring whether and how periostin plays a role in the promotion of periodontal regeneration by DFSCs. By tracking the fate of DFSCs, it was found that DFSCs significantly contributed to periodontal regeneration in rat periodontal defects while they had a low survival rate. They highly expressed periostin and improved the immune microenvironment in the defect area, especially via the recruitment and reprogramming of macrophages. Silencing periostin attenuated the effects of DFSCs in promoting periodontal regeneration and regulating macrophages. Recombinant human periostin (rhPeriostin) could not only directly promote macrophage reprogramming through the integrin αM/phosphorylated extracellular signal-regulated kinase (p-Erk)/Erk signaling pathway, but it also exhibited the potential to promote periodontal regeneration in rats when loaded in a collagen matrix. These results indicated that periostin is actively involved in the process by which DFSCs promote periodontal regeneration through the regulation of macrophages and is a promising molecular agent to promote periodontal regeneration. This study provides new insight into the mechanism by which DFSCs promote periodontal regeneration and suggests a new approach for periodontal regeneration therapy.

An Activatable NIR Fluorescent Probe for NAD(P)H and Its Application to the Real-Time Monitoring of p53 Abnormalities In Vivo.

NAD(P)H is crucial for biosynthetic reactions and antioxidant functions. However, the current probes developed for detecting NAD(P)H in vivo require intratumoral injection, which limited their application for animal imaging. To address this issue, we have developed a liposoluble cationic probe, KC8, which exhibits excellent tumor-targeting ability and near-infrared (NIR) fluorescence after reaction with NAD(P)H. By using KC8, it was demonstrated for the first time that the level of NAD(P)H in the mitochondria of living colorectal cancer (CRC) cells was highly related to the abnormality of the p53. Furthermore, KC8 was successfully used to differentiate not only between tumor and normal tissue but also between tumors with p53 abnormality and normal tumors when administered intravenously. Finally, we evaluated tumor heterogeneity through two fluorescent channels after treating a tumor with 5-Fu. This study provides a new tool for real-time monitoring of the p53 abnormality of CRC cells.

Biomineralization-inspired mineralized hydrogel promotes the repair and regeneration of dentin/bone hard tissue.

Maxillofacial hard tissue defects caused by trauma or infection often affect craniofacial function. Taking the natural hard tissue structure as a template, constructing an engineered tissue repair module is an important scheme to realize the functional regeneration and repair of maxillofacial hard tissue. Here, inspired by the biomineralization process, we constructed a composite mineral matrix hydrogel PAA-CMC-TDM containing amorphous calcium phosphates (ACPs), polyacrylic acid (PAA), carboxymethyl chitosan (CMC) and dentin matrix (TDM). The dynamic network composed of Ca2+·COO- coordination and ACPs made the hydrogel loaded with TDM, and exhibited self-repairing ability and injectability. The mechanical properties of PAA-CMC-TDM can be regulated, but the functional activity of TDM remains unaffected. Cytological studies and animal models of hard tissue defects show that the hydrogel can promote the odontogenesis or osteogenic differentiation of mesenchymal stem cells, adapt to irregular hard tissue defects, and promote in situ regeneration of defective tooth and bone tissues. In summary, this paper shows that the injectable TDM hydrogel based on biomimetic mineralization theory can induce hard tissue formation and promote dentin/bone regeneration.

Fast-Specific Fluorescent Probes to Visualize Norepinephrine Signaling Pathways and Its Flux in the Epileptic Mice Brain.

Norepinephrine (NE) is synthesized in the locus coeruleus and widely projected throughout the brain and spinal cord. It regulates various actions and consciousness linked to a variety of neurological diseases. A "hunting-shooting" strategy was proposed in this work to improve the specificity and response rate of an NE fluorescent probe: 2-(cyclohex-2-en-1-ylidene)malononitrile derivatives were chosen as a fluorophore. To create a dual-site probe, an aldehyde group was added to the ortho of the ester group (or benzene sulfonate). Because of its excellent electrophilic activity, the aldehyde group could rapidly "hunt" the amino group and then form an intramolecular five-membered ring via the nucleophilic reaction with the ß-hydroxyl group. The -NH- in the five-membered ring "shoots" the adjacent ester group, releasing the fluorophore and allowing for rapid and specific NE detection. The NE release and reuptake ″emetic″-″swallow″ transient process is captured and visualized under the action of the primary NE receptor drug. Furthermore, by introducing halogen into the fluorophore to lengthen the absorption wavelength, improve lipid solubility, and adjust the pKa appropriately, the probe successfully penetrated the blood-brain barrier (BBB). In situ synchronous probe imaging was used to detect the NE level in the brains of epileptic and normal mice, and abnormal expression of NE in the brain was discovered during epilepsy. Brain anatomy was used to examine the distribution and level changes of NE in various brain regions before and after epilepsy. This research provides useful tools and a theoretical foundation for diagnosing and treating central nervous system diseases early.

A Space-Dependent 'Enzyme-Substrate' Type Probe based on 'Carboxylesterase-Amide Group' for Ultrafast Fluorescent Imaging Orthotopic Hepatocellular Carcinoma.

Fast and selective fluorescence imaging for a biomarker to related-disease diagnosis remains a significant challenge due to complex physical environment. Human carboxylesterase (CE) is expected to be a potential biomarker of hepatocellular carcinoma (HCC) to improve the accuracy of diagnosis. However, existing probes for CE has slow response rate and low selectivity. Herein, the amide group is selected as CE-responsive sites based on the "substrate-hydrolysis enzymatic reaction" approach. From a series of off-on probes with leave groups in the amide unit, probe JFast is screened with the optimal combination of rapid response rate and high selectivity toward CE. JFast requires only 150 s to reach the maximum fluorescence at 676 nm in the presence of CE and free from the interference of other esterase. Computational docking simulations indicate the shortest distance between the CE and active site of JFast . Cell and in vivo imaging present that the probe can turn on the liver cancer cells and tumor region precisely. Importantly, JFast is allowed to specifically image orthotopic liver tumor rather than metastatic tumor and distinguish human primary liver cancer tissue from adjacent ones. This study provides a new tool for CE detection and promotes advancements in accurate HCC diagnosis.

Dental follicle cells-derived small extracellular vesicles inhibit pathogenicity of Porphyromonas gingivalis.

OBJECTIVE: It aims to explore the effect of dental follicle cells-derived small extracellular vesicles (D-sEVs) with or without lipopolysaccharides (LPS) pretreating on the pathogenicity of Porphyromonas gingivalis (P. gingivalis). METHODS: The antibacterial effects of D-sEV were evaluated by measuring the growth, biofilm formation, gingipains, and type IX secretion system (T9SS) expression of P. gingivalis. And the influence of D-sEV on P. gingivalis adhesion, invasion, cytotoxicity, and host immune response was examined in gingival epithelial cells (GECs). Then P. gingivalis treated with D-sEV was applied to investigate the pathogenicity in experimental periodontitis of mice. RESULTS: It showed that both D-sEV and P. gingivalis LPS-pretreated D-sEV (L-D-sEV) could target P. gingivalis, inhibit their growth and biofilm formation, and hinder the attachment and invasion in GECs, therefore remarkably decreasing P. gingivalis cytotoxicity and the expression of IL-1ß and IL-6 in GECs. In addition, they significantly reduced the expression of P. gingivalis virulence factors (gingipains and T9SS). In vivo, it showed that the bacteria in the gingiva were significantly decreased after sEV treatment. Meanwhile, less bone loss and fewer inflammatory cells infiltration and osteoclast formation in D-sEV and L-D-sEV groups. CONCLUSION: Both D-sEV and L-D-sEV were proven to inhibit the pathogenicity of P. gingivalis and thus prevented the development of periodontitis.

Biomimetic Peridontium Patches for Functional Periodontal Regeneration.

The unique structure of the periodontium, including the alveolar bone, cementum, and periodontal ligament (PDL), presents difficulties for the regeneration of its intricate organization. Irreversible structural breakdown of the periodontium increases the risk of tooth loosening and loss. Although the current therapies can restore the periodontal hard tissues to a certain extent, the PDL with its high directionality of multiple groups with different orientations and functions cannot be reconstructed. Here, biomimetic peridontium patches (BPPs) for functional periodontal regeneration using a microscale continuous digital light projection bioprinting method is reported. Orthotopic transplantation in the mandibles shows effective periodontal reconstruction. The resulting bioengineered tissues closely resembles natural periodontium in terms of the "sandwich structures," especially the correctly oriented fibers, showing different and specific orientation in different regions of the tooth root, which has never been found in previous studies. Furthermore, after the assessment of clinically functional properties it is found that the regenerative periodontium can achieve stable tooth movement under orthodontic migration force with no adverse consequences. Overall, the BPPs promote reconstruction of the functional periodontium and the complex microstructure of the periodontal tissue, providing a proof of principle for the clinical functional treatment of periodontal defects.