Luminescence-Tunable Polynorbornenes for Simultaneous Multicolor Imaging in Subcellular Organelles.

Through modular ROMP (ring-opening metathesis polymerization), biofunctional polynorbornenes are designed and fabricated from panchromatic fluorophores, bioactive peptides, and polyethylene glycol solubilizer for organelle-specific multicolor imaging. Attributed to the free permutation and combination of highly fluorescent red rhodamine B, green dichlorofluorescein and blue 9,10-diphenylanthracene fluorophores as well as signaling peptide sequences of F xrF xK and TAT, we successfully realize simultaneous multicolor imaging toward lysosomes and mitochondria in living cells first utilizing polymeric scaffolds. If more biofunctions could be incorporated, modularly designed copolymer would provide a promising opportunity to facilitate multitasking application to monitoring intracellular alterations and elucidating complex biological processes.

Modular Design of Poly(norbornenes) for Organelle-Specific Imaging in Tumor Cells.

Through modular ROMP (ring-opening metathesis polymerization) directly from monomeric norbornenes of bioactive peptides, rhodamine B chromophore, and PEG solubilizer, we designed and synthesized a series of water-soluble poly(norbornenes) with organelle-specific imaging capability in tumor cells. For the selection of FxrFxK, TAT, and SV40 peptide sequences, these fluorescence probes exhibited different targeting specificity toward mitochondria, lysosome, and nucleolus, respectively, based on the same poly(norbornene) backbonds. More importantly, the ROMP strategy enables selective combination from various monomers and allows programmable biofunctionalization via peptide sequence permutations, which would greatly extend the biomedical applications such as imaging, diagnosis, and therapy for these synthetic polymers.

Adsorption mechanism of hexavalent chromium on electron beam-irradiated aged microplastics: Novel aging processes and environmental factors.

Microplastics are widely present in the natural environment and exhibit a strong affinity for heavy metals in water, resulting in the formation of microplastics composite heavy metal pollutants. This study investigated the adsorption of heavy metals by electron beam-aged microplastics. For the first time, electron beam irradiation was employed to degrade polypropylene, demonstrating its ability to rapidly age microplastics and generate a substantial number of oxygen-containing functional groups on aged microplastics surface. Adsorption experiments revealed that the maximum adsorption equilibrium capacity of hexavalent chromium by aged microplastics reached 9.3 mg g-1. The adsorption process followed second-order kinetic model and Freundlich model, indicating that the main processes of heavy metal adsorption by aged microplastics are chemical adsorption and multilayer adsorption. The adsorption of heavy metals on aged microplastics primarily relies on the electrostatic and chelation effects of oxygen-containing functional groups. The study results demonstrate that environmental factors, such as pH, salinity, coexisting metal ions, humic acid, and water matrix, exert inhibitory effects on the adsorption of heavy metals by microplastics. Theoretical calculations confirm that the aging process of microplastics primarily relies on hydroxyl radicals breaking carbon chains and forming oxygen-containing functional groups on the surface. The results indicate that electron beam irradiation can simultaneously oxidize and degrade microplastics while reducing hexavalent chromium levels by approximately 90%, proposing a novel method for treating microplastics composite pollutants. Gas chromatography-mass spectrometry analysis reveals that electron beam irradiation can oxidatively degrade microplastics into esters, alcohols, and other small molecules. This study proposes an innovative and efficient approach to treat both microplastics composite heavy metal pollutants while elucidating the impact of environmental factors on the adsorption of heavy metals by electron beam-aged microplastics. The aim is to provide a theoretical basis and guidance for controlling microplastics composite pollution.

Single-cell transcriptomics reveals cell atlas and identifies cycling tumor cells responsible for recurrence in ameloblastoma.

Ameloblastoma is a benign tumor characterized by locally invasive phenotypes, leading to facial bone destruction and a high recurrence rate. However, the mechanisms governing tumor initiation and recurrence are poorly understood. Here, we uncovered cellular landscapes and mechanisms that underlie tumor recurrence in ameloblastoma at single-cell resolution. Our results revealed that ameloblastoma exhibits five tumor subpopulations varying with respect to immune response (IR), bone remodeling (BR), tooth development (TD), epithelial development (ED), and cell cycle (CC) signatures. Of note, we found that CC ameloblastoma cells were endowed with stemness and contributed to tumor recurrence, which was dominated by the EZH2-mediated program. Targeting EZH2 effectively eliminated CC ameloblastoma cells and inhibited tumor growth in ameloblastoma patient-derived organoids. These data described the tumor subpopulation and clarified the identity, function, and regulatory mechanism of CC ameloblastoma cells, providing a potential therapeutic target for ameloblastoma.

Non-Calcifying/Langerhans Cell-Rich Calcifying Epithelial Odontogenic Tumour: A Critical Review of the Rare and Distinctive Entity.

BACKGROUND: The study aims to analyse the non-calcifying/Langerhans cell rich (NCLC) subtype of calcifying epithelial odontogenic tumour (CEOT).  METHOD: The features of cases of the NCLC subtype of CEOT noted in the English literature by PubMed as well as 3 new cases were reviewed. RESULTS: Overall, twenty-one cases were noted. Many were women in the fourth to sixth decades (male-to-female ratio =1 to 2). Radiologically, the lesion is often unilocular with resorption of the affected teeth. Nineteen of the 21 cases occurred in the maxilla, especially the anterior portion. On pathological examination, epithelial cells are noted in non-calcifying amyloid-rich fibrous stroma. The main differential diagnosis is the amyloid subtype of central odontogenic fibroma. Immunohistochemical studies revealed the tumour epithelial cells were positive for cytokeratins and p63 and contained CD1a, S-100, and langerin-positive Langerhans cells. On a median follow-up of 2 years, one patient had a recurrence one year after curettage. CONCLUSION: The NCLC subtype of CEOT is unique as it contains significant numbers of Langerhans cells and has clinicopathological features distinctive from classic CEOT.

Wnt/ß-catenin signaling participates in cementoblast/osteoblast differentiation of dental follicle cells.

Dental follicle cells (DFCs) are reported to contain stem cells. The canonical Wnt signaling pathway plays an important role in stem cell self-renewal and tooth development through ß-catenin expression. The objective of this study was to investigate whether Wnt/ß-catenin signaling pathway participates in the cementoblast/osteoblast differentiation of rat DFCs. Immunohistochemistry was used to compare the expression of ß-catenin in rat mandibular first molars from postnatal days 1-13. The effects of Wnt/ß-catenin signaling on DFCs in vitro were examined by lithium chloride (LiCl) treatment by immunofluorescence, cell counting, dual-luciferase reporter assays, western blotting, and alkaline phosphatase activity analysis. ß-Catenin expression was absent in the dental follicles on days 1 and 3 in vivo. It then progressively increased from days 5 to 13. In vitro studies of the DFCs showed that LiCl stimulation caused ß-catenin, which was mainly located in the cell membrane and cytoplasm of DFCs, to be immediately transferred to the nucleus and led to the inhibition of proliferation at 12 and 24 hr. LiCl treatment also downregulated the levels of phosphorylated-ß-catenin, while upregulating the levels of total ß-catenin, nuclear ß-catenin, osteocalcin, runt-related transcription factor 2, and collagen type I. In addition, LiCl enhanced the ß-catenin/T-cell factor luciferase activity and alkaline phosphatase activity. These results suggest that Wnt/ß-catenin signaling pathway positively regulates the cementoblast/osteoblast differentiation of the DFCs.

Proteomic analysis of the effects of CSF-1 and IL-1α on dental follicle cells.

Tooth eruption is a complex physiological process involving both osteogenesis and bone resorption. Signals from the dental follicle (DF) regulate bone remodeling during tooth eruption. Interleukin-1α (IL-1α) may be the initial promoter of tooth eruption, whereas colony­stimulating factor­1 (CSF­1) may attract monocytes into the DF and stimulate osteoclast differentiation. In the present study, differential proteomics was employed to explore protein changes in rat DF cells (DFCs) under the effects of CSF­1 and IL­1α. A total of 47 protein spots were differentially expressed in rat DFCs, and 40 protein spots were identified by MALDI­TOF­MS. The identified proteins were grouped into functional categories including cytoskeletal proteins, metal­binding proteins, proteins involved in secretion and degradation, cell cycle proteins and stress proteins. In IL­1α­induced rat DFCs, 31 proteins were upregulated compared with the control and included heat shock protein ß­1 (HSP25, also known as HSP27/HSPß1), vimentin, TMEM43, the GTP­binding protein Rab­3D, 6­pyruvoyl tetrahydrobiopterin synthase and actin. In total, 7 proteins were downregulated, including serum albumin, GIPC1, DNA primase large subunit, cullin­5 and cyclin­G1. In CSF­1­induced rat DFCs, 3 proteins were upregulated and 7 proteins were downregulated when compared with the controls. The upregulated proteins included the GTP­binding protein Rab­3D and α­actin. The downregulated proteins included cullin­5, serum albumin, PDZ domain­containing protein and cyclin­G1. The differential expression of vimentin, actin, HSP25 and Rab­3D was verified by western blotting and reverse transcription­quantitative polymerase chain reaction analyses. The present findings provide an insight into the mechanisms involved in tooth eruption.

Botulinum Toxin A for the Treatment of a Child with SUNCT Syndrome.

Background. Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) syndrome is an unusual cause of headache, mainly described in older adults, and is rare in children. Pain attacks may be severe, frequent, and prolonged. The therapeutic benefits of many drugs are disappointing. Patient and Methods. A 12-year-old boy suffered severe headache and toothache for 20 days. As treatment with nonsteroidal anti-inflammatory drugs, anticonvulsants, and steroids proved ineffective, he was treated with ipsilateral multisite subcutaneous injections of botulinum toxin A 70 U around the orbit, the temporal area, and the upper gum. Results. The pain had reduced in frequency and severity by the fourth day after treatment and had completely disappeared after 7 days. There were no side effects or recurrence during a subsequent 17-month follow-up period. Conclusion. Botulinum toxin A can be used to treat the first episode of SUNCT in children over the age of 12 years.

[Preparation and clinical application of Teflon-wire piston and stapes height measurer].

With Teflon, and a tiny stainless steel needle of a number 7 injector and an acupuncture needle,Teflon-piston and a measurer of the stapes height were prepared respectively of stapedectomy for treatment of otosclerosis. Good clinical results were achieved with these simple and useful devices.

A modular designed copolymer with anti-thrombotic activity and imaging capability.

Through a modular ROMP (ring-opening metathesis polymerization) strategy, a random copolymer with anti-thrombotic activity and imaging capability has been constructed from RGD, rhodamine B and PEG modified norbornene monomers. As we expected, these tri-component polynorbornenes exhibit significant enhancement in anti-thrombotic efficacy and bioavailability in vivo.

Expression of matrilin-2 and -4 in human dental pulps during dentin-pulp complex wound healing.

INTRODUCTION: Matrilin-2 and matrilin-4 are members of the matrilin family displaying broad tissue distribution. We recently reported that matrilin-2 showed significant down-regulation during the odontogenic differentiation of dental pulp cells (DPCs). It is reported that matrilin-4 was the only extracellular matrix biogenesis and organization-related gene detected in odontoblasts but not DPCs. However, the exact role of matrlin-2 and -4 in dental pulps remains unclear. The aim of our study was to analyze the expression of matrilin-2 and -4 in human dental pulps and their relation to dentin-pulp complex wound healing. METHODS: Immunohistology was performed on the paraffin-embedded tissue sections of human dental pulps from sound and deep carious teeth. Matrilin-2 and -4 messenger RNAs were detected by quantitative real-time reverse-transcription polymerase chain reaction, and the proteins were shown by immunofluorescence and Western blot during odontogenic differentiation of the DPCs. RESULTS: In the sound dental pulp, matrilin-2 immunoreactivity was observed throughout the pulp, whereas matrilin-4 was observed only in the odontoblast layer. In deep carious dental pulp, matrilin-2 protein was weakly stained, whereas matrilin-4 was detected in the pulp under the carious lesion. During odontogenic differentiation of DPCs, the expression of matrilin-2 messenger RNA was down-regulated within 14 days followed by a statistical increase on day 21, and the matrilin-2 protein level was down-regulated within the 3 weeks, whereas the messenger RNA and protein expressions of matrilin-4 increased in a time-dependent manner. CONCLUSIONS: Matrilin-2 and matrilin-4 have been shown in human dental pulps and might be involved in the dentin-pulp complex wound-healing process.

[Therapeutic effect of ossicular reconstruction with bioceramic or porous macromolecular polyethylene partial ossicular replacement prosthesis in patients with tympanosclerosis].

OBJECTIVE: To evaluate the effect of ossicular reconstruction with partial ossicular replacement prosthesis (PORP) in patients with tympanosclerosis. METHODS: The data of 31 cases of tympanosclerosis treated between 1992 and 2009 were reviewed. Of the 31 patients, 17 (17 ears) underwent ossicular reconstruction with porous macromolecular polyethylene PORP, and 14 (14 ears) with bioceramic PORP. All the patients were followed up for 3-24 months. RESULTS: Significant improvement was found in postoperative speech frequency (500, 1000, 2000 Hz) pure tone average (PTA) and air-bone gap (ABG) (P < 0.05) after the treatments without statistically significant differences between the two groups (P > 0.05). CONCLUSION: Porous macromolecular polyethylene and bioceramic are valuable ossicular prosthesis for tympanosclerosis.

[Expression and biological roles of heat shock protein 25 in rat dental follicle cells].

OBJECTIVE: To examine the expression of heat shock protein 25 (HSP-25) in dental rat follicles in vivo and in vitro in order to investigate the possible effect of HSP-25 on cell proliferation and alkaline phosphatase (ALP) activity. METHODS: The expression of HSP-25 in mandibles of postnatal rats from day 1, 3, 5, 7, 9, 11 was examined by immunohistochemistry in vitro, the expression of HSP-25 in the dental follicle cells was detected by the indirect immunofluorescence method. Methyl thiazolyl tetrazolium (MTT) assay, flowcytometry and ALP assay were used to detect the effect of HSP-25 on rat dental follicles. RESULTS: HSP-25 expression was absent or weak in rat dental follicle cells at early postnatal stage and present from day 5 till day 11. HSP-25 was detected in the cytoplasm of cultured dental follicle cells. MTT results showed no effect could be detected on dental follicle cell proliferation after stimulation of different concentrations of HSP-25 on day 1, 2, 3. Flowcytometry results also exhibited no difference in cell cycles after stimulation of HSP-25 at 0 microg/L and 100 microg/L. HSP-25 at a concentration of 50 microg/L and 100 microg/L could up-regulate the ALP activity on day 9. CONCLUSIONS: Expression of HSP-25 increases chronologically in the rat dental follicle cells. HSP-25 locates in the cytoplasm of cultured rat dental follicle cells. HSP-25 has no effect on the proliferation of dental follicle cells, however it can up-regulate the ALP activity.