Cluster analyses using the amino acid content predicted from the coding regions (13 genes) of complete vertebrate mitochondrial genomes as traits grouped selected vertebrates into two clusters, terrestrial and aquatic...Cluster analyses using the amino acid content predicted from the coding regions (13 genes) of complete vertebrate mitochondrial genomes as traits grouped selected vertebrates into two clusters, terrestrial and aquatic vertebrates. Exceptions were the hagfish (Eptatretus burgeri), thought to be an early ancestor of vertebrates, and the black spotted frog (Rana nigromaculata), which is terrestrial as an adult and aquatic as a larva. These two species fall into the terrestrial and aquatic clusters, respectively. Using the nucleotide (G, C, T and A) content in the coding and non-coding regions, and in the complete genome as traits, similar results were obtained but with some additional exceptions. In addition, phylogenetic analyses of 16S rRNA sequences produced a consistent result. The results of this study indicated that vertebrate evolution is controlled by natural selection under both an internal bias as a result of nucleotide replacement genomic rules, and an external bias caused by environmental biospheric conditions.展开更多
As a potent anticancer drug,gambogic acid(GA)suffers from its poor water solubility and low chemical stability and shows a limited clinical outcome.To address this problem,we report here a simple and effective strateg...As a potent anticancer drug,gambogic acid(GA)suffers from its poor water solubility and low chemical stability and shows a limited clinical outcome.To address this problem,we report here a simple and effective strategy to immobilize and deliver GA using a reducible diblock poly(amino acid)as a model.The electrostatic interaction between GA and polymer enables a high drug loading content up to 53.6%.Moreover,the drug complexation induces a micelle-to-vesicle transformation,combined with a conformation tra nsition from random coil to a-helix.The hierarchically assembled drug nanocomplexes can serve as a smart carrier for efficient cell internalization and triggered release of multiple drugs under intracellular acidic and reductive conditions,resulting in a synergistic antitumor efficacy in vitro.This work provides a new insight into the drug-carrier interaction and a facile nanoplatform for drug delivery applications.展开更多
As one of the top global health problems,the effective treatment of cancer is one of the most urgent clinical challenges.Currently,the main treatments for cancer include surgery,chemotherapy,radiotherapy,and gene ther...As one of the top global health problems,the effective treatment of cancer is one of the most urgent clinical challenges.Currently,the main treatments for cancer include surgery,chemotherapy,radiotherapy,and gene therapy etc.Chemotherapy is one of the most commonly used treatments,however it has limitations such as highly toxic side effects and low drug utilization rate that limit its application.Gene therapy,as an emerging cancer treatment,has limitations such as drug instability,off-target effects and low internalization efficiency.Poly(amino acid)s carriers with good biocompatibility,degradability and multifunctionality as drug carriers have received much attention,as they can reduce the toxic side effects of chemotherapy,improve drug utilization,and enhance the internalization efficiency and utilization of gene drugs.However,little attention has been paid to the nature of the carriers themselves.This paper reviews the immunomodulatory,anti-inflammatory,antioxidant,internalization-promoting and apoptosispromoting functions of poly(amino acid)s drug carriers in tumor therapy to provide a theoretical basis for different carrier-drug-adapted synergistic therapies.展开更多
Polyion complex （PIC） micelles were spontaneously formed in aqueous solutions through electrostatic interaction between two oppositely charged block copolymers, poly（N-isopropylacrylamide）-b-poly（L-glutamic acid...Polyion complex （PIC） micelles were spontaneously formed in aqueous solutions through electrostatic interaction between two oppositely charged block copolymers, poly（N-isopropylacrylamide）-b-poly（L-glutamic acid） and poly（N-isopropylacrylamide）-b-poly（L-lysine）. Their controlled synthesis was achieved via the ring opening polymerization of N-carboxyanhydrides （NCA）, ε-benzyloxycarbonyl-L-lysine （Lys（Z）-NCA） or γ-benzyl-L-glutamate （BLG-NCA） with amino-terminated poly（N-isopropylacrylamide） macroinitiator and the subsequent deprotection reaction. The formation of PIC micelles was confirmed by dynamic light scattering and transmission electron microscopy. Turbidimetric characterization suggested that the formed PIC micelles had a concentration-dependent thermosensitivity and their phase transition behaviors could be easily adjusted either by the block length of coplymers or the concentration of micelles.展开更多
Novel aromatic-aliphatic poly（amide-imide）s containing chiral units in the main chain and hydroxyl benzamide units in the side chain have been obtained from the step-growth polymerization of 3,5-diamino-N-（4-hydrox...Novel aromatic-aliphatic poly（amide-imide）s containing chiral units in the main chain and hydroxyl benzamide units in the side chain have been obtained from the step-growth polymerization of 3,5-diamino-N-（4-hydroxyphenyl） benzamide （2） with different chiral diacid chlorides （la-le）. Theoretical calculations were done by means of computational chemistry methods to narrate the stable conformation and orientation of each diacid chloride monomers under reaction conditions. These polymers were characterized by conventional techniques. The resulting polymers show good thermal stability. Other physical properties of polymers including crystallinity, inherent viscosity and morphological characteristics were also studied.展开更多
文摘Cluster analyses using the amino acid content predicted from the coding regions (13 genes) of complete vertebrate mitochondrial genomes as traits grouped selected vertebrates into two clusters, terrestrial and aquatic vertebrates. Exceptions were the hagfish (Eptatretus burgeri), thought to be an early ancestor of vertebrates, and the black spotted frog (Rana nigromaculata), which is terrestrial as an adult and aquatic as a larva. These two species fall into the terrestrial and aquatic clusters, respectively. Using the nucleotide (G, C, T and A) content in the coding and non-coding regions, and in the complete genome as traits, similar results were obtained but with some additional exceptions. In addition, phylogenetic analyses of 16S rRNA sequences produced a consistent result. The results of this study indicated that vertebrate evolution is controlled by natural selection under both an internal bias as a result of nucleotide replacement genomic rules, and an external bias caused by environmental biospheric conditions.
基金supported by the National Natural Science Foundation of China(Nos.51873118,21474064,52022062)the KeyResearch and Development Program of Science and Technology Department of Sichuan Province(No.2019YFS0514)+2 种基金Science and Technology Project of Chengdu(No.2019-YF05-00784-SN)the Project of State Key Laboratory of Polymer Materials Engineering(No.sklpme2020-2-03)the Fundamental Research Funds for Central Universities。
文摘As a potent anticancer drug,gambogic acid(GA)suffers from its poor water solubility and low chemical stability and shows a limited clinical outcome.To address this problem,we report here a simple and effective strategy to immobilize and deliver GA using a reducible diblock poly(amino acid)as a model.The electrostatic interaction between GA and polymer enables a high drug loading content up to 53.6%.Moreover,the drug complexation induces a micelle-to-vesicle transformation,combined with a conformation tra nsition from random coil to a-helix.The hierarchically assembled drug nanocomplexes can serve as a smart carrier for efficient cell internalization and triggered release of multiple drugs under intracellular acidic and reductive conditions,resulting in a synergistic antitumor efficacy in vitro.This work provides a new insight into the drug-carrier interaction and a facile nanoplatform for drug delivery applications.
基金supported by the National Natural Science Foundation of China(Nos.51973243 and 52173150)the Shenzhen Basic Research Project(No.JCYJ20190807155801657)the International Cooperation and Exchange of the National Natural Science Foundation of China(No.51820105004)。
文摘As one of the top global health problems,the effective treatment of cancer is one of the most urgent clinical challenges.Currently,the main treatments for cancer include surgery,chemotherapy,radiotherapy,and gene therapy etc.Chemotherapy is one of the most commonly used treatments,however it has limitations such as highly toxic side effects and low drug utilization rate that limit its application.Gene therapy,as an emerging cancer treatment,has limitations such as drug instability,off-target effects and low internalization efficiency.Poly(amino acid)s carriers with good biocompatibility,degradability and multifunctionality as drug carriers have received much attention,as they can reduce the toxic side effects of chemotherapy,improve drug utilization,and enhance the internalization efficiency and utilization of gene drugs.However,little attention has been paid to the nature of the carriers themselves.This paper reviews the immunomodulatory,anti-inflammatory,antioxidant,internalization-promoting and apoptosispromoting functions of poly(amino acid)s drug carriers in tumor therapy to provide a theoretical basis for different carrier-drug-adapted synergistic therapies.
基金financially supported by the National Natural Science Foundation of China (Nos. 20904053, 51021003,51173184)the Ministry of Science and Technology of China (International cooperation program 2011RI0001)the Program of the Science and Technology of Changchun (No. 2010061)
文摘Polyion complex （PIC） micelles were spontaneously formed in aqueous solutions through electrostatic interaction between two oppositely charged block copolymers, poly（N-isopropylacrylamide）-b-poly（L-glutamic acid） and poly（N-isopropylacrylamide）-b-poly（L-lysine）. Their controlled synthesis was achieved via the ring opening polymerization of N-carboxyanhydrides （NCA）, ε-benzyloxycarbonyl-L-lysine （Lys（Z）-NCA） or γ-benzyl-L-glutamate （BLG-NCA） with amino-terminated poly（N-isopropylacrylamide） macroinitiator and the subsequent deprotection reaction. The formation of PIC micelles was confirmed by dynamic light scattering and transmission electron microscopy. Turbidimetric characterization suggested that the formed PIC micelles had a concentration-dependent thermosensitivity and their phase transition behaviors could be easily adjusted either by the block length of coplymers or the concentration of micelles.
文摘Novel aromatic-aliphatic poly（amide-imide）s containing chiral units in the main chain and hydroxyl benzamide units in the side chain have been obtained from the step-growth polymerization of 3,5-diamino-N-（4-hydroxyphenyl） benzamide （2） with different chiral diacid chlorides （la-le）. Theoretical calculations were done by means of computational chemistry methods to narrate the stable conformation and orientation of each diacid chloride monomers under reaction conditions. These polymers were characterized by conventional techniques. The resulting polymers show good thermal stability. Other physical properties of polymers including crystallinity, inherent viscosity and morphological characteristics were also studied.
