Spatiotemporal Expression Patterns of Critical Genes Involved in FGF Signaling During Morphogenesis and Odontogenesis of Deciduous Molars in Miniature Pigs.

The fibroblast growth factor (FGF) pathway plays an important role in epithelial-mesenchymal interactions during tooth development. Nevertheless, how the ligands, receptors, and antagonists of the FGF pathway are involved in epithelial-mesenchymal interactions remains largely unknown. Miniature pigs exhibit tooth anatomy and replacement patterns like those in humans and hence can serve as large animal models. The present study investigated the spatiotemporal expression patterns of critical genes encoding FGF ligands (FGF3, FGF4, FGF7, and FGF9), antagonists (SPRY2 and SPRY4) and receptors (FGFR1, FGFR2, and FGFR3) in the third deciduous molars of miniature pigs at the cap (embryonic day 40, E40), early bell (E50), and late bell (E60) stages. The results of in situ hybridization (ISH) with tyramide signal amplification and of qRT-PCR analysis revealed increased expression of FGF7, FGFR1, FGFR2, and SPRY4 in dental epithelium and of FGF7 and FGFR1 in mesenchyme from E40 to E50. In contrast, the results revealed decreased expression of FGF3, FGF4, FGF9, and FGFR3 in dental epithelium and of FGF4, FGF9, FGFR2, and FGFR3 in the mesenchyme from E40 to E60. Mesenchyme signals of FGF3, FGF4, FGF7, SPRY2, FGFR2, and FGFR3 were concentrated in the odontoblast layer from E50 to E60. The distinct expression patterns of these molecules indicated elaborate regulation during dental morphogenesis. Our results provide a foundation for further investigation into fine-tuning dental morphogenesis and odontogenesis by controlling interactions between dental epithelium and mesenchyme, thus promoting tooth regeneration in large mammals.

A molecularly engineered fully bio-derived phosphorylated furan-based flame retardant for biomass-based fabrics.

With the increasing awareness of environmental protection, the demand for eco-friendly bio-derived flame-retardant for textiles has received increasing attention. In this work, a fully bio-derived phosphorylated furan-based flame retardant (FAP) was synthesized by the Schiff reaction of furan-based compounds (furfural and furfurylamine). To evaluate the application scope and flame retardant efficiency of FAP, cotton fabrics and PLA nonwovens were selected as biomass-based representatives of natural fiber materials and synthetic fiber materials, respectively. Significantly, based on the composition of furan ring, phosphorus and nitrogen containing components of FAP, excellent charring and flame retardant properties of coated cotton fabrics and PLA nonwovens can be expected. TGA results showed that the residual char of C-FAP-3 and P-FAP-3 were 39.7% (increased by 267.6%) and 16.7% (increased by 215.1%), respectively, higher than those of control cotton (10.8%) and PLA nonwoven (5.3%). Cone test results exhibited that the peak heat release rate (PHRR) and total heat release (THR) values of C-FAP-3 were sharply decreased by 69.4% and 37.8%, respectively. P-FAP-3 also displayed a significant reduction in PHRR, implying high flame retardancy of C-FAP-3 and P-FAP-3. Notably, through the weight gains of FAP coating on cotton and PLA as well as the final LOI and VBT results of the flame retardant treated fabrics, it can be preliminarily inferred that control cotton fabrics are more likely to achieve better flame retardant effects than PLA. Additionally, the facile synthetic strategy of fully bio-derived flame retardants is expected to promote the development of green flame retardant strategies for high-performance textiles.

Ultra-light-weight, anti-flammable and water-proof cellulosic aerogels for thermal insulation applications.

Cellulosic aerogels (CNF) are considered naturally available thermal insulating materials as substitutes for conventional polymeric aerogels owing to their extensive sources, low density, low thermal conductivity, sustainability and biodegradability. However, cellulosic aerogels suffer from high flammability and hygroscopicity. In this work, a novel P/N-containing flame retardant (TPMPAT) was synthesized to modify cellulosic aerogels to improve their anti-flammability. TPMPAT/CNF aerogels were further modified by polydimethylsiloxane (PDMS) to enhance the water-proof characteristics. Although the addition of TPMPAT and/or PDMS slightly increased the density and thermal conductivity of the composite aerogels, those values were still comparable to the commercial polymeric aerogels. Compared with pure CNF aerogel, the cellulose aerogel modified by TPMPAT and/or PDMS had higher T-10%, T-50% and Tmax, which indicated that the modified cellulose aerogels have better thermal stability. TPMPAT modification made CNF aerogels highly hydrophilic, while TPMPAT/CNF aerogel modified by PDMS became a highly hydrophobic material with a water contact angle (WCA) of 142°. Pure CNF aerogel burned rapidly after ignition, showing a low limiting oxygen index (LOI) of 23.0% and no UL-94 grade. In contrast, both TPMPAT/CNF-30% and PDMS-TPMPAT/CNF-30% showed self-extinction behaviors with a UL-94 V-0 grade, implying high fire resistance. Combined with high anti-flammability and hydrophobicity, the ultra-light-weight cellulosic aerogels show great potential for thermal insulation applications.

Chitin based multi-layered coatings with flame retardancy an approach to mimic nacre: Synthesis, characterization and mechanical properties.

Nacre mimetic coatings are attractive candidates for food packaging, electronics, textiles, protective insulation, and flame retardant materials. Inspired by the hierarchical structure of nacre, we present an environmentally friendly strategy to construct robust and flame retardant films using chitin, which is an abundantly available biopolymer. Chitin was phosphorylated to make it water-soluble. Multilayered films were constructed by assembling poly (vinyl alcohol) (PVA), graphene oxide (GO) nanosheets, phosphorylated chitin (p. chitin), and laponite (LAP) via Layer-by-Layer (LbL) and vacuum-assisted filtration (VAF) assemblies. SEM micrographs revealed the nacre-like layered structure while photographic images showed a similar sheen to that of the mother of pearl. The fabricated coatings possess good mechanical properties with a reduced modulus of 25.53 GPa and hardness of 1.45 GPa. In addition, multilayered films exhibited iridescence and attractive flame retardancy. We believe that our strategy of embedding chitin offers cost-effective and environmentally friendly coatings for textiles, food packaging, barrier, and electronic materials.

Recent Developments of Nanoparticles in the Treatment of Photodynamic Therapy for Cervical Cancer.

Photodynamic therapy (PDT) is a photoactivation or photosensitization process, wherein the photosensitizer (PS) is activated under appropriate wavelengths. Conventional antitumor therapy for cervical cancer includes surgery, radiotherapy, and chemotherapy. However, these techniques are accompanied by some evident shortcomings. PDT is considered an emerging minimally invasive treatment for cervical cancer. In recent years, new PSs have been synthesized because of the long absorption wavelength, good solubility, and high tumor targeting ability. Studies also showed that the synergistic combination of nanomaterials with PSs resulted in considerable benefits compared with the use of small-molecule PSs alone. The compounds can act both as a drug delivery system and PS and enhance the photodynamic effect. This review summarizes the application of some newly synthesized PSs and PS-combined nanoparticles in cervical cancer treatment to enhance the efficiency of PDT. The mechanism and influencing factors of PDT are further elaborated.