Myosin II mediates Shh signals to shape dental epithelia via control of cell adhesion and movement.

The development of ectodermal organs begins with the formation of a stratified epithelial placode that progressively invaginates into the underlying mesenchyme as the organ takes its shape. Signaling by secreted molecules is critical for epithelial morphogenesis, but how that information leads to cell rearrangement and tissue shape changes remains an open question. Using the mouse dentition as a model, we first establish that non-muscle myosin II is essential for dental epithelial invagination and show that it functions by promoting cell-cell adhesion and persistent convergent cell movements in the suprabasal layer. Shh signaling controls these processes by inducing myosin II activation via AKT. Pharmacological induction of AKT and myosin II can also rescue defects caused by the inhibition of Shh. Together, our results support a model in which the Shh signal is transmitted through myosin II to power effective cellular rearrangement for proper dental epithelial invagination.

Covalent Immobilization of Natural Biomolecules on Chitin Nanocrystals.

As a highly crystalline and renewable natural polymer nanomaterial, chitin nanocrystals (ChNCs) have attracted intense interest in the biomedical field. The structure of a ChNC is composed of an acetylglucosamine unit containing two hydroxyl groups and an acetyl group. The acetyl group can be converted to the active amino group through deacetylation, which is under the condition of maintaining the rod-like morphology and high crystalline property and is beneficial for the following modification and potential application. We investigated the relationship between different treatments and varied crystallinities of the modified ChNC, which obtained surface amino groups and aldehyde groups and retained high crystallinity. The natural biomolecules were covalently immobilized on the surface of the ChNC. The etherification was performed based on the hydroxyl groups. Based on the amino groups and the aldehyde groups, the carboxyamine and Knoevenagel condensation reactions were realized on ChNCs. Finally, natural biomolecule-modified ChNCs showed no or low cytotoxicity, antibacterial properties, and high antioxidant properties, which extended their potential biomedical applications.

METTL3 enhances dentinogenesis differentiation of dental pulp stem cells via increasing GDF6 and STC1 mRNA stability.

BACKGROUND: The dentinogenesis differentiation of dental pulp stem cells (DPSCs) is controlled by the spatio-temporal expression of differentiation related genes. RNA N6-methyladenosine (m6A) methylation, one of the most abundant internal epigenetic modification in mRNA, influences various events in RNA processing, stem cell pluripotency and differentiation. Methyltransferase like 3 (METTL3), one of the essential regulators, involves in the process of dentin formation and root development, while mechanism of METTL3-mediated RNA m6A methylation in DPSC dentinogenesis differentiation is still unclear. METHODS: Immunofluorescence staining and MeRIP-seq were performed to establish m6A modification profile in dentinogenesis differentiation. Lentivirus were used to knockdown or overexpression of METTL3. The dentinogenesis differentiation was analyzed by alkaline phosphatase, alizarin red staining and real time RT-PCR. RNA stability assay was determined by actinomycin D. A direct pulp capping model was established with rat molars to reveal the role of METTL3 in tertiary dentin formation. RESULTS: Dynamic characteristics of RNA m6A methylation in dentinogenesis differentiation were demonstrated by MeRIP-seq. Methyltransferases (METTL3 and METTL14) and demethylases (FTO and ALKBH5) were gradually up-regulated during dentinogenesis process. Methyltransferase METTL3 was selected for further study. Knockdown of METTL3 impaired the DPSCs dentinogenesis differentiation, and overexpression of METTL3 promoted the differentiation. METTL3-mediated m6A regulated the mRNA stabiliy of GDF6 and STC1. Furthermore, overexpression of METTL3 promoted tertiary dentin formation in direct pulp capping model. CONCLUSION: The modification of m6A showed dynamic characteristics during DPSCs dentinogenesis differentiation. METTL3-mediated m6A regulated in dentinogenesis differentiation through affecting the mRNA stability of GDF6 and STC1. METTL3 overexpression promoted tertiary dentin formation in vitro, suggesting its promising application in vital pulp therapy (VPT).

Rapid Assembly of Cellulose Microfibers into Translucent and Flexible Microfluidic Paper-Based Analytical Devices via Wettability Patterning.

Microfluidic paper-based analytical devices (µPADs) are emerging as powerful analytical platforms in clinical diagnostics, food safety, and environmental protection because of their low cost and favorable substrate properties for biosensing. However, the existing top-down fabrication methods of paper-based chips suffer from low resolution (>200 µm). Additionally, papers have limitations in their physical properties (e.g., thickness, transmittance, and mechanical flexibility). Here, we demonstrate a bottom-up approach for the rapid fabrication of heterogeneously controlled paper-based chip arrays. We simply print a wax-patterned microchip with wettability contrasts, enabling automatic and selective assembly of cellulose microfibers to construct predefined paper-based microchip arrays with controllable thickness. This paper-based microchip printing technology is feasible for various substrate materials ranging from inorganic glass to organic polymers, providing a versatile platform for the full range of applications including transparent devices and flexible health monitoring. Our bottom-up printing technology using cellulose microfibers as the starting material provides a lateral resolution down to 42 ± 3 µm and achieves the narrowest channel barrier down to 33 ± 2 µm. As a proof-of-concept demonstration, a flexible paper-based glucose monitor is built for human health care, requiring only 0.3 µL of sample for testing.

Intra- and Intermolecular Hydrogen Bonding in Miscible Blends of CO2/Epoxy Cyclohexene Copolymer with Poly(Vinyl Phenol).

In this study, we synthesized a poly(cyclohexene carbonate) (PCHC) through alternative ring-opening copolymerization of CO2 with cyclohexene oxide (CHO) mediated by a binary LZn2OAc2 catalyst at a mild temperature. A two-dimensional Fourier transform infrared (2D FTIR) spectroscopy indicated that strong intramolecular [C-H···O=C] hydrogen bonding (H-bonding) occurred in the PCHC copolymer, thereby weakening its intermolecular interactions and making it difficult to form miscible blends with other polymers. Nevertheless, blends of PCHC with poly(vinyl phenol) (PVPh), a strong hydrogen bond donor, were miscible because intermolecular H-bonding formed between the PCHC C=O units and the PVPh OH units, as evidenced through solid state NMR and one-dimensional and 2D FTIR spectroscopic analyses. Because the intermolecular H-bonding in the PCHC/PVPh binary blends were relatively weak, a negative deviation from linearity occurred in the glass transition temperatures (Tg). We measured a single proton spin-lattice relaxation time from solid state NMR spectra recorded in the rotating frame [T1ρ(H)], indicating full miscibility on the order of 2-3 nm; nevertheless, the relaxation time exhibited a positive deviation from linearity, indicating that the hydrogen bonding interactions were weak, and that the flexibility of the main chain was possibly responsible for the negative deviation in the values of Tg.

Environment-friendly bio-based controlled-release phosphate fertilizer with waste kitchen oil as coating material: Preparation, characterization, and mechanisms.

Recently, Bio-based polyurethane controlled-release fertilizers (BPCF) have been developed rapidly owing to their environmental friendliness, renewability, and low cost. However, the unsatisfying controlled release prohibits their large-scale direct application in agricultural production. Here, we prepared bio-based controlled-release phosphate (P) fertilizers using harmful waste kitchen oils (WKO) as coating materials. The membrane shell surface was modified with multi-walled carbon nanotubes (CNT), and superhydrophobic controlled-release phosphorus fertilizers (SCRF) were obtained. After CNT modification, the controlled release period of SCRF was greatly improved. Phosphorus released period of SCRF reached over 67 d while that of BPCF was merely ∼49 d. Additionally, the surface energy, cracks, roughness, microstructure, cross-linking degree, etc., of the membrane shells were measured. The results showed that CNT greatly improved the hydrophobic properties of the membrane shells. The findings indicated the application of modified WKO with great agricultural value in preparing environment-friendly BPCFs.

Striking Back against Fungal Infections: The Utilization of Nanosystems for Antifungal Strategies.

Fungal infections have become a major health concern, given that invasive infections by Candida, Cryptococcus, and Aspergillus species have led to millions of mortalities. Conventional antifungal drugs including polyenes, echinocandins, azoles, allylamins, and antimetabolites have been used for decades, but their limitations include off-target toxicity, drug-resistance, poor water solubility, low bioavailability, and weak tissue penetration, which cannot be ignored. These drawbacks have led to the emergence of novel antifungal therapies. In this review, we discuss the nanosystems that are currently utilized for drug delivery and the application of antifungal therapies.

Meso/Microporous Carbons from Conjugated Hyper-Crosslinked Polymers Based on Tetraphenylethene for High-Performance CO2 Capture and Supercapacitor.

In this study, we successfully synthesized two types of meso/microporous carbon materials through the carbonization and potassium hydroxide (KOH) activation for two different kinds of hyper-crosslinked polymers of TPE-CPOP1 and TPE-CPOP2, which were synthesized by using Friedel-Crafts reaction of tetraphenylethene (TPE) monomer with or without cyanuric chloride in the presence of AlCl3 as a catalyst. The resultant porous carbon materials exhibited the high specific area (up to 1100 m2 g-1), total pore volume, good thermal stability, and amorphous character based on thermogravimetric (TGA), N2 adsoprtion/desorption, and powder X-ray diffraction (PXRD) analyses. The as-prepared TPE-CPOP1 after thermal treatment at 800 °C (TPE-CPOP1-800) displayed excellent CO2 uptake performance (1.74 mmol g-1 at 298 K and 3.19 mmol g-1 at 273 K). Furthermore, this material possesses a high specific capacitance of 453 F g-1 at 5 mV s-1 comparable to others porous carbon materials with excellent columbic efficiencies for 10,000 cycle at 20 A g-1.

CapsNet-SSP: multilane capsule network for predicting human saliva-secretory proteins.

BACKGROUND: Compared with disease biomarkers in blood and urine, biomarkers in saliva have distinct advantages in clinical tests, as they can be conveniently examined through noninvasive sample collection. Therefore, identifying human saliva-secretory proteins and further detecting protein biomarkers in saliva have significant value in clinical medicine. There are only a few methods for predicting saliva-secretory proteins based on conventional machine learning algorithms, and all are highly dependent on annotated protein features. Unlike conventional machine learning algorithms, deep learning algorithms can automatically learn feature representations from input data and thus hold promise for predicting saliva-secretory proteins. RESULTS: We present a novel end-to-end deep learning model based on multilane capsule network (CapsNet) with differently sized convolution kernels to identify saliva-secretory proteins only from sequence information. The proposed model CapsNet-SSP outperforms existing methods based on conventional machine learning algorithms. Furthermore, the model performs better than other state-of-the-art deep learning architectures mostly used to analyze biological sequences. In addition, we further validate the effectiveness of CapsNet-SSP by comparison with human saliva-secretory proteins from existing studies and known salivary protein biomarkers of cancer. CONCLUSIONS: The main contributions of this study are as follows: (1) an end-to-end model based on CapsNet is proposed to identify saliva-secretory proteins from the sequence information; (2) the proposed model achieves better performance and outperforms existing models; and (3) the saliva-secretory proteins predicted by our model are statistically significant compared with existing cancer biomarkers in saliva. In addition, a web server of CapsNet-SSP is developed for saliva-secretory protein identification, and it can be accessed at the following URL: http://www.csbg-jlu.info/CapsNet-SSP/. We believe that our model and web server will be useful for biomedical researchers who are interested in finding salivary protein biomarkers, especially when they have identified candidate proteins for analyzing diseased tissues near or distal to salivary glands using transcriptome or proteomics.

Impact of submandibular gland preservation in neck management of early-stage buccal squamous cell carcinoma on locoregional control and disease-specific survival.

BACKGROUND: The feasibility of submandibular gland (SMG) preservation in oral squamous cell carcinoma (SCC) has occasionally been analyzed, but the differences in survival associated with the presence or absence of SMG preservation remain unknown. We aimed to prospectively evaluate the oncologic results of SMG preservation in cT1-2 N0 buccal SCC. METHODS: This was a prospective, non-randomized cohort study. Patients with surgically treated cT1-2 N0 buccal SCC were prospectively enrolled and divided into two groups based on the management of the SMG. Level 1b lymph nodes were categorized into six groups based on the positional relationship between the lymph node and the SMG. The main study endpoints were locoregional control (LRC) and disease-specific survival (DSS). RESULTS: A total of 31 of the 137 included patients underwent SMG-sparing neck dissection. Patients with SMG preservation were likely to be young persons. Superior metastasis occurred in 11 patients with a prevalence of 8.0%, followed by an anterior metastasis rate of 5.1%, and no metastases developed deeply or within the SMG. The 5-year LRC rates in the SMG-sparing and SMG-excision groups were 74 and 75%, respectively, and the difference was not significant (p = 0.970). The 5-year DSS rates in the SMG-sparing and SMG-excision groups were 74 and 69%, respectively, and the difference was not significant (p = 0.709). CONCLUSIONS: SMG involvement was rare, and the superior group carried the highest risk for lymph node metastasis. SMG-sparing neck dissection is selectively suggested in cT1-2 N0 buccal SCC patients, and could avoid postoperative asymmetric appearance and dry mouth.

Oncologic outcome of marginal mandibulectomy in squamous cell carcinoma of the lower gingiva.

BACKGROUND: There is a large amount of controversy about the best management of the mandible in oral squamous cell carcinoma (SCC), mainly owing to the inability to acquire accurate bone invasion status. Therefore, our goal was to analyse the oncologic safety in patients undergoing marginal mandibulectomy (MM) for cT1-2 N0 SCC of the lower gingiva. METHODS: Patients undergoing MM for untreated cT1-2 N0 SCC of the lower gingiva were retrospectively enrolled. The main endpoints of interest were locoregional control (LRC) and disease-specific survival (DSS). RESULTS: A total of 142 patients were included in the analysis, and a pathologic positive node was noted in 27 patients. Cortical invasion was reported in 23 patients, and medullary invasion was reported in 9 patients. The 5-year LRC and DSS rates were 85 and 88%, respectively. Patients with bone invasion had a significantly higher risk for recurrence than patients without bone invasion. However, the DSS was similar in patients with versus without bone invasion. Patients with a high neutrophil lymphocyte ratio had a higher risk for worse prognosis. CONCLUSIONS: The oncologic outcome in patients undergoing MM for cT1-2 N0 SCC of the lower gingiva was favourable; bone invasion was not uncommon, but it significantly decreased the prognosis in patients undergoing MM.

Lineage tracing of epithelial cells in developing teeth reveals two strategies for building signaling centers.

An important event in organogenesis is the formation of signaling centers, which are clusters of growth factor-secreting cells. In the case of tooth development, sequentially formed signaling centers known as the initiation knot (IK) and the enamel knot (EK) regulate morphogenesis. However, despite the importance of signaling centers, their origin, as well as the fate of the cells composing them, remain open questions. Here, using lineage tracing of distinct epithelial populations, we found that the EK of the mouse incisor is derived de novo from a group of SRY-box 2 (Sox2)-expressing cells in the posterior half of the tooth germ. Specifically, EK progenitors are located in the posterior ventral basal layer, as demonstrated by DiI labeling of cells. Lineage tracing the formed EK with ShhCreER , which encodes an inducible Cre recombinase under the control of the Sonic hedgehog promoter, at subsequent developmental stages showed that, once formed, some EK cells in the incisor give rise to differentiated cells, whereas in the molar, EK cells give rise to the buccal secondary EK. This work thus establishes the developmental origin as well as the fate of the EK and reveals two strategies for the emergence of serially formed signaling centers: one through de novo establishment and the other by incorporation of progeny from previously formed signaling centers.

Facile preparation of magnetic molecularly imprinted polymers for the selective extraction and determination of dexamethasone in skincare cosmetics using HPLC.

Dexamethasone-imprinted polymers were fabricated by reversible addition-fragmentation chain transfer polymerization on the surface of magnetic nanoparticles under mild polymerization conditions, which exhibited a narrow polydispersity and high selectivity for dexamethasone extraction. The dexamethasone-imprinted polymers were characterized by scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectrometry, and vibrating sample magnetometry. The adsorption performance was evaluated by static adsorption, kinetic adsorption and selectivity tests. The results confirmed the successful construction of an imprinted polymer layer on the surface of the magnetic nanoparticles, which benefits the characteristics of high adsorption capacity, fast mass transfer, specific molecular recognition, and simple magnetic separation. Combined with high-performance liquid chromatography, molecularly imprinted polymers as magnetic extraction sorbents were used for the rapid and selective extraction and determination of dexamethasone in skincare cosmetic samples, with the accuracies of the spiked samples ranging from 93.8 to 97.6%. The relative standard deviations were less than 2.7%. The limit of detection and limit of quantification were 0.05 and 0.20 µg/mL, respectively. The developed method was simple, fast and highly selective and could be a promising method for dexamethasone monitoring in cosmetic products.

Facile preparation of polydopamine-coated imprinted polymers on the surface of SiO2 for estrone capture in milk samples.

Estrone molecularly imprinted polymers were synthesized through the self-polymerization of dopamine on the surface of silica gels, which had the characteristics of mild polymerization conditions, simple reaction procedure and good specific recognition ability for estrone. The estrone molecularly imprinted polymers were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and nitrogen adsorption-desorption tests. The characterization confirmed that the imprinted polymers were successfully grafted on the surface of silica gels. Through investigating the adsorption performance, the prepared estrone molecularly imprinted polymers exhibited high adsorption capacity, fast mass transfer, as well as excellent selectivity toward estrone. The estrone molecularly imprinted polymers as the solid-phase extraction adsorbent coupled with high-performance liquid chromatography was developed to determine estrone from the milk samples. The developed estrone molecularly imprinted polymer solid-phase extraction with high-performance liquid chromatography method exhibited satisfactory specificity, precision, accuracy and good linearity relationship in the range of 0.2-20 µg/mL. The developed method is simple, fast, effective and high specificity method and it provides a new method to detect the residues of estrone in animal foods.

IGF-1 C Domain-Modified Hydrogel Enhances Cell Therapy for AKI.

Low cell retention and engraftment after transplantation limit the successful application of stem cell therapy for AKI. Engineered microenvironments consisting of a hydrogel matrix and growth factors have been increasingly successful in controlling stem cell fate by mimicking native stem cell niche components. Here, we synthesized a bioactive hydrogel by immobilizing the C domain peptide of IGF-1 (IGF-1C) on chitosan, and we hypothesized that this hydrogel could provide a favorable niche for adipose-derived mesenchymal stem cells (ADSCs) and thereby enhance cell survival in an AKI model. In vitro studies demonstrated that compared with no hydrogel or chitosan hydrogel only, the chitosan-IGF-1C hydrogel increased cell viability through paracrine effects. In vivo, cotransplantation of the chitosan-IGF-1C hydrogel and ADSCs in ischemic kidneys ameliorated renal function, likely by the observed promotion of stem cell survival and angiogenesis, as visualized by bioluminescence imaging and attenuation of fibrosis. In conclusion, IGF-1C immobilized on a chitosan hydrogel provides an artificial microenvironment for ADSCs and may be a promising therapeutic approach for AKI.

Renewable microbial lipid production from Oleaginous Yeast: some surfactants greatly improved lipid production of Rhodosporidium toruloides.

Microbial oil is drawing increasing interest worldwide as an alternative non-food oil feedstock for biodiesel industry. Nowadays researchers have been increasingly focused on the improvement of microbial oil production process. Oleaginous yeast Rhodosporidium toruloides (R. toruloides) is considered an important candidate due to its excellent capabilities of lipid accumulation, broad adaptabilities to various carbon substrates, and the potential of co-production of some pigments. In present work, the individual effects of non-ionic, cationic, and anionic surfactant on cell growth and lipid accumulation of R. toruloides were investigated for the first time. Interesting results were noticed when some anionic surfactants were supplemented. The most significant effect was observed with addition of 0.2 % (w/v) sodium lignosulfonate, that biomass concentration, lipid concentration, and lipid yield was increased by 25.1, 44.9, and 15.7 %, respectively. The fatty acid compositions of R. toruloides lipids remained unchanged, which is similar to that of vegetable oils, and is considered potential feedstock for biodiesel preparation.

Reconstruction of full-thickness buccal defects with submental island flap.

Our goal was to introduce the application of submental island flap in reconstructing through-and-through cheek defects. From January 2009 to January 2013, 7 patients (5 men and 2 women) with full-thickness buccal defects due to tumor resection received submental flap reconstruction at the Affiliated Tumor Hospital of Zhengzhou University; surgical procedure and success rate as well as functional results were described. Distal partial necrosis occurred in 1 flap, but all flaps survived. All patients were capable of maintaining a regular oral diet, and no patients complained of an inability to eat in a public setting, microstomia, or drooling; the appearance was reported to be good or acceptable in all cases, and the mean postoperative mouth-open width was 4.2 (range, 3.7-5.0) cm. One patient had a local recurrence in the follow-up. Therefore, submental island flap is a reliable procedure for through-and-through buccal defects in selected patients.

Bilayer metallic nanofilms as broadband antireflection coatings in terahertz optical systems.

We present the potential of ultrathin bilayer metallic nanofilms for use as broadband antireflection coatings in the terahertz frequency range. The metallic layers are modeled using a wave-impedance matching approach. The experimental and theoretical results are in good agreement. Further, a novel method using our broadband antireflection coatings is proposed to eliminate unwanted reflections that interfere with the important reflection from the sample in terahertz reflection measurement. The proposed method significantly improves the calculation of the optical properties of liquid and biological samples.

Isolation of oleaginous yeast (Rhodosporidium toruloides) mutants tolerant of sugarcane bagasse hydrolysate.

Rhodosporidium toruloides is a lipid-producing yeast, the growth of which is severely suppressed when hydrolysates of lignocellulosic biomass are used as carbon source. This is probably due to the toxic substances, such as organic acids, furans, and phenolic compounds produced during the preparation of the hydrolysates. In order to solve this problem, R. toruloides cultures were subjected to atmospheric room-temperature plasma mutagenesis, resulting in the isolation of mutants showing tolerance to sugarcane bagasse hydrolysate (SBH). Three mutant strains, M11, M13, and M18, were found to grow with producing lipids with SBH as carbon source. M11 in particular appeared to accumulate higher levels (up to 60% of dry cell weight) of intracellular lipids. Further, all three mutant strains showed tolerance of vanillin, furfural, and acetic acid, with different spectra, suggesting that different genetic determinants are involved in SBH tolerance.