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1.
Carbohydr Polym ; 303: 120456, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36657861

RESUMO

As one of the most important biopolymers, starch has been applied to replace petroleum-derived polymers for "green" materials. Discovery of novel solvents and understanding of the solvent effects are critical challenges for the destruction of strong hydrogen bonds of starch molecules for manufacturing bio-based materials. Herein, two ionic liquids (ILs), 1-ethyl-3-methyl-imidazolium mesylate ([Emim][MS]) and 1-ethyl-3-methyl-imidazolium tartrate ([Emim][Tar]), were explored as novel solvents for starch. Their effects on phase transition behaviors, microstructure, hydrogen-bond interaction, crystalline structure, micromorphology and thermal stability of corn starch were compared systematically. With the IL/H2O ratio increasing, the starch/IL/H2O mixtures underwent endothermic, exothermic/endothermic and exothermic processes, sequentially. However, the starch properties were very different in two ILs-water systems, which were closely related to the solvent composition and IL structure. These differences were further explained by the interactions among starch, water and the two ILs on the basis of the quantum chemical calculations. It was found that [Emim][MS] had a stronger interaction with water than starch, whereas [Emim][Tar] preferred to bind with starch. This study not only provided experimental supports for understanding the starch behaviors in novel "green" solvents, but also laid the theoretical foundation for starch modification and industrial applications of starch-based materials in more appropriate solvents.

2.
Int J Pharm ; 601: 120553, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33794325

RESUMO

Pancreatic cancer (PC) is an aggressive form of cancer with dense stroma and immune-suppressive microenvironment, which are the major barriers for treatment. To address such barriers, this study aimed to develop a sequential receptor-mediated mixed-charge targeted delivery system for PC based on 2-(3-((S)-5-amino-1-carboxypentyl)-ureido) pentanedioate (ACUPA-) and triphenylphosphonium (TPP+) modified nanomicelles containing ingenol-3-mebutate (I3A), which was named ACUPA-/TPP+-I3A or ACUPA/TPP-I3A. ACUPA/TPP-I3A induced immunogenic cell death (ICD), which significantly increased the number of tumor-infiltrating T lymphocytes, activated adaptive immunity, and achieved superior survival time. I3A, a novel anticancer drug, could induce PC cell necrosis to release damage-associated molecular patterns, thereby activating adaptive immunity. With certain ratios of negatively (ACUPA-) and positively (TPP+) charged ligands, ACUPA/TPP-I3A acquired a negative charge in plasma (pH 7.4, to inhibit aggregation and uptake in the circulation) and was neutral in the acidic tumor microenvironment (pH 5.0-6.0, to overcome electrostatic hindrances and facilitate transcytosis). Furthermore, neovascular endothelium-specific ACUPA enabled rapid transcytosis of ACUPA/TPP-I3A across tumor vessel walls, entering into endosome/lysosomes (pH 4.5-5.0, its charge became positive and exhibited lysosome escape). Then, ACUPA/TPP-I3A selectively targeted mitochondria, which correlated with TPP-mediated effect. Finally, I3A was released to induce ICD that activated adaptive immunity and achieved superior survival time. Therefore, reshaping of the tumor microenvironment and potentiating antitumor immunity using ACUPA-/TPP+-I3A constituted a novel strategy to prolong the survival time.


Assuntos
Nanopartículas , Neoplasias Pancreáticas , Linhagem Celular Tumoral , Humanos , Morte Celular Imunogênica , Nanomedicina , Neoplasias Pancreáticas/tratamento farmacológico , Microambiente Tumoral
3.
Mitochondrial DNA B Resour ; 4(2): 3441-3442, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33366030

RESUMO

The chloroplast genome sequence of Ardisia mamillata has been characterized based on the High-throughput sequencing technology. The complete cp genome of A. mamillata is 138,323 bp in length, containing LSC region of 86,325 bp, SSC region of 18,434 bp, and two IR regions of 25,999 bp. The overall GC content f A. mamillata cp genome is 37.1%. The annotated complete cp genome contains 113 genes, including 79 protein-coding genes, 8 rRNA genes, and 30 tRNA genes. Further, the phylogenetic analysis suggested that the A. mamillata and A. polysticta are phylogenetically related to each other.

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