2 research outputs found
Thermally Stable Metallic Nanoparticles Prepared via Core-Cross-linked Block Copolymer Micellar Nanoreactors
Thermally
stable metallic nanoparticles (MNPs) are highly desirable
for the melt processing of polymer nanocomposites. However, due to
the high surface energy penalty and decreased melting temperature,
MNPs are easy to agglomerate and lose their unique properties if there
is no protection or confinement layer. In this work, we report a facile
and efficient way to synthesize thermally stable MNPs using core-cross-linked
polystyrene-<i>b</i>-polyÂ(4-vinylpyridine) (PS-<i>b</i>-P4VP) reverse micelles as nanoreactors. From infrared results, gold,
silver, and palladium ions exhibited distinctive coordination to the
4VP groups with varying chelation strengths. Compared to the non-cross-linked
micelles, 1,4-dibromobutane (DBB)-cross-linking of the P4VP cores
provided several advantages. First, it prevented severe swelling of
the P4VP cores caused by the reducing agents and subsequent merger
of swollen micelles. Second, the quaternized P4VP with hydrophilicity
enhanced the uptake speed of precursor metal ions into the cores.
Third, the cross-linked cores greatly stabilized the MNPs against
the high-temperature environment (<i>e.g.</i>, 110 °C
for 40 h in toluene). In addition, the solubility of the reducing
agents also played an important role. Anhydrous hydrazine could swell
the P4VP cores and concentric core–shell particle morphology
was obtained. On the contrary, triethylsilane could not swell the
P4VP cores and thus eccentric core–shell particle morphology
was observed. Only the concentric core–shell MNPs exhibited
good thermal stability, whereas the eccentric core–shell MNPs
did not. This work suggested that these thermally stable MNPs could
be good candidates for the melt processing of functional polymer nanocomposites
A prognostic model of drug tolerant persister-related genes in lung adenocarcinoma based on single cell and bulk RNA sequencing data
Background: Acquired resistance to targeted drugs is a major challenge in cancer. The drug-tolerant state has been proposed to be an initial step towards acquisition of real drug-resistance. Drug tolerant persister (DTP) cells are purported to survive during treatment and stay dormant for several years. Single cell sequencing can provide a comprehensive landscape of gene expression in DTP cells, which can facilitate investigation of heterogeneity of a drug tolerant state and identification of new anticancer targets. Methods: The genetic profiling of DTPs was explored by integrating Gene Expression Omnibus (GEO) datasets, and a prognostic signature of DTP-related genes (DTPRGs) in lung adenocarcinoma of TCGA LUAD cohort was constructed. The scores of infiltrating immune cells were calculated and activity of immune-related pathways was evaluated by single-sample gene set enrichment analysis (ssGSEA). Functional enrichment analysis of the DTPRGs between low- and high-risk groups was performed. Immune cell subtypes and immune-related pathways were analyzed. Results: An 11-gene panel (MT2A, UBE2S, CLTB, KRT7, IGFBP3, CTSH, NPC2, HMGA1, HNRNPAB, DTYMK, and IHNA) was established. DTPRGs were mainly correlated with nuclear division, chromosome segregation, and cell cycle pathways. Infiltration of immune cells was lower in the high-risk group while the inflammation-promoting and MCH-class I response pathway had higher activity in the high-risk group. A nomogram was generated with prognostic accuracy, further validated using clinical outcomes following therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). Discussion: A prognostic model of lung adenocarcinoma based on DTPRGs was constructed. Targeting DTP cells is a potential therapeutic approach to prevent a drug tolerant state