G Spinelli

Halloysite nanotubes loaded with peppermint essential oil as filler for functional biopolymer film

The purpose of this paper is to show how a functional bionanocomposite film with both antioxidant and antimicrobial activities was successfully prepared by the filling of a pectin matrix with modified Halloysite nanotubes (HNT) containing the essential peppermint oil (PO). Firstly, HNT surfaces were functionalized with cucurbit[6]uril (CB[6]) molecules with the aim to enhance the affinity of the nanofiller towards PO, which was estimated by means of HPLC experiments. The HNT/CB[6] hybrid was characterized by several methods (thermogravimetry, FT-IR spectroscopy and scanning electron microscopy) highlighting the influence of the supramolecular interactions on the composition, thermal behavior and morphology of the filler. Then, a pectin+HNT/CB[6] biofilm was prepared by the use of the casting method under specific experimental conditions in order to favor the entrapment of the volatile PO into the nanocomposite structure. Water contact angle measurements, thermogravimetry and tensile tests evidenced the effects of the modified filler on the thermo-mechanical and wettability properties of pectin, which were correlated to the microscopic structure of the biocomposite film. In addition, PO release in food simulant solvent was investigated at different temperatures (4 and 25°C), whereas the antioxidant activity of the nanocomposite film was estimated using the DPPH method. Finally, we studied the in vitro antibacterial activity of the biofilm against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive), which were isolated by beef and cow milk, respectively. These experiments were carried out at specific temperatures (4, 37 and 65°C) that can be useful for a multi-step food conservation. This paper puts forwards an easy strategy to prepare a functional sustainable edible film with thermo-sensitive antioxidant/antimicrobial activity.

BRAFV600E mutation, TIMP-1 upregulation, and NF-κB activation: closing the loop on the papillary thyroid cancer trilogy

BRAF(V600E) is the most common mutation found in papillary thyroid carcinoma (PTC). Tissue inhibitor of metalloproteinases (TIMP-1) and nuclear factor (NF)-κB have been shown to play an important role in thyroid cancer. In particular, TIMP-1 binds its receptor CD63 on cell surface membrane and activates Akt signaling pathway, which is eventually responsible for its anti-apoptotic activity. The aim of our study was to evaluate whether interplay among these three factors exists and exerts a functional role in PTCs. To this purpose, 56 PTC specimens were analyzed for BRAF(V600E) mutation, TIMP-1 expression, and NF-κB activation. We found that BRAF(V600E) mutation occurs selectively in PTC nodules and is associated with hyperactivation of NF-κB and upregulation of both TIMP-1 and its receptor CD63. To assess the functional relationship among these factors, we first silenced BRAF gene in BCPAP cells, harboring BRAF(V600E) mutation. We found that silencing causes a marked decrease in TIMP-1 expression and NF-κB binding activity, as well as decreased invasiveness. After treatment with specific inhibitors of MAPK pathway, we found that only sorafenib was able to increase IκB-α and reduce both TIMP-1 expression and Akt phosphorylation in BCPAP cells, indicating that BRAF(V600E) activates NF-κB and this pathway is MEK-independent. Taken together, our findings demonstrate that BRAF(V600E) causes upregulation of TIMP-1 via NF-κB. TIMP-1 binds then its surface receptor CD63, leading eventually to Akt activation, which in turn confers antiapoptotic behavior and promotion of cell invasion. The recognition of this functional trilogy provides insight on how BRAF(V600E) determines cancer initiation, progression, and invasiveness in PTC, also identifying new therapeutic targets for the treatment of highly aggressive forms.

Expression of homeobox-containing genes in the sea urchin (Parancentrotus lividus) embryo.

Two homeobox-containing genes that belong to different homeodomain classes have been isolated from a sea urchin geonomic library. One, PlHbox11, is the sea urchin homologue of the human and mouse Hox B3 gene, the other, PlHbox12, shows about 55% identity with paired class genes. Expression profile analysis of the two sea urchin Hbox genes suggests that they play different roles during embryogenesis. In fact, PlHbox11 transcripts are rare and are detected only in the pluteus larva and in the Aristotles lantern and intestine of the adult. The PlHbox12 gene is, on the contrary, transiently expressed in the very early embryo already at the four cell stage; it accumulates at the 64 cell stage and disappears at later stages of development.In situ hybridization experiments to 16 and 32 cell stage whole mount embryos showed localization of the PlHbox12 mRNA to part of the mesomere-macromere region of the early cleavage embryo. These observations suggest a possible role of this gene in early events of cell specification.

Hybrid supramolecular gels of Fmoc-F/halloysite nanotubes: systems for sustained release of camptothecin

Supramolecular gel hybrids obtained by self-assembly of Fmoc-l-phenylalanine (Fmoc-F) in the presence of functionalized halloysite nanotubes (f-HNT) were obtained in biocompatible solvents and employed as carriers for the delivery of camptothecin (CPT) molecules. The synthesis of the new f-HNT material as well as its characterization are described. The properties of the hybrid hydrogels and organogels were analyzed by several techniques. The presence of small amounts of f-HNT allows good dispersion of the tubes and the subsequent formation of homogeneous gels. The experimental results show that f-HNT functions only as an additive in the hybrid gels and does not demonstrate gelator behavior. The in vitro kinetic release from both f-HNT/CPT and Fmoc-F/f-HNT/CPT was studied in media that imitates physiological conditions, and the factors controlling the release process were determined and discussed. Furthermore, the antiproliferative in vitro activities of the gels were evaluated towards human cervical cancer HeLa cells. A comparison of data collected in both systems shows the synergistic action of f-HNT and the gel matrix in controlling the release of CPT in the media and maintaining the drug in its active form. Finally, a comparison with pristine HNT is also reported. This study suggests a suitable strategy to obtain two-component gel hybrids based on nanocarriers with controlled drug carrier capacity for biomedical applications.