Polymer Chemistry
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2018
·Vol. 9
·期 29
·3974-3986
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IF 4.927
Pan Li,Yingying Song,Chang-Ming Dong
Controlled polymerization to synthesize hyperbranched polypeptides (HBPPs) with tunable degree of branching (DB) and molecular weight (MW) is still challenging in synthetic polypeptides and their biomaterials fields. A new photocaged amino acid monomer Nε-(1-(2-nitrophenyl)ethoxycarbonyl)-L-lysine-N-carboxyanhydride (NPE-Lys NCA) was designed. Without the addition of any catalyst/initiator and/or scavenger, lysine-based HBPPs were directly synthesized from the UV phototriggered ring-opening polymerization (ROP) of NPE-Lys NCA by a one-pot method and at room temperature. Their branched structures were fully characterized by means of 1H NMR, 1H,1H-COSY, 1H,13C-HSQC, and quantitative 13C NMR techniques. The effects of irradiation intensity and N2 flow rate on the phototriggered ROP and MWs, DBs, and conformations of the resulting polypeptides were investigated. At a lower irradiation intensity of 0.3 mW cm−2, the actual MWs (Mw,LLS) of P1 to P3 increased from 34.9 kDa to 62.8 kDa when N2 flow rate shifted to 300 mL min−1; DB reduced from 0.43 to 0.21; and the α-helix content rose from 35% to 63%, while the random coil decreased from 50% to 26%. By tuning the UV irradiation intensity and/or the N2 flow rate, this methodology can efficiently produce lysine-based HBPPs with tunable DBs of 0.21–0.54 and higher actual MWs of 13.7–62.8 kDa.
研究领域:
高分子化学
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生物材料科学
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DOI
高影响因子
Polymer Chemistry
·
2011
·Vol. 3
·期 7
·1918-1925
·
IF 0
Jin Han,Bo Zhao,Aijin Tang,Yanqin Gao,Chao Gao
Fast and scalable production of hyperbranched polythioether-ynes was achieved by applying sequential click chemistry (SCC) via couple-monomer methodology (CMM). As a typical example, thiol-halogen click-like reaction employing strong base, KOH and thiol-yne click reaction via UV irradiation were used for precursor preparation and polymerization, respectively. Two series of hyperbranched polythioether-ynes employing two kinds of di-thiols with different reactivity have been prepared within 10 h and characterized with 1H NMR spectroscopy and gel permeation chromatography. The hyperbranched polymers (HPs) derived from 1,6-hexanedithiol reached high weight-average molecular weight (Mw) of 230500, high weight-average degree of polymerization (DPw) of 1224 and high degree of branching (DB) of 0.82–0.68. Postmodification of abundant alkyne terminal groups afford HPs with a greatly enhanced DB of 0.96. Heat-initiated polymerization was also attempted. The present study clearly demonstrates the robustness of application of SCC technique in the CMM strategy for fast, scalable preparation of multifunctional HPs.
研究领域:
材料科学
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化学工程
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DOI
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Wenliang Liu,Yan Wang,Yuqi Wang,Xiaohan Li,Kai Qi,Jiqian Wang,Hai Xu
Cancers are among the leading causes of death currently. Conventional radiotherapy and chemotherapy are of limited use in the treatment of some tumors due to their high toxicity and drug resistance. Plasma photothermal therapy has attracted extensive attention for the treatment of tumors due to photothermal properties of plasmonic nanoparticles, such as gold (Au) nanoparticles, to achieve local hyperthermia with low toxicity and high efficiency. Herein, we report a kind of special black noble-metal core–shell nanostructure, with silver (Ag) nanocubes as the core and amino acid-encoded highly branched Au nanorods as the shells (l-CAg@Au and d-CAg@Au). The proposed growth of l-CAg@Au and d-CAg@Au nanocomposites was an amino acid-encoded Stranski–Krastanov mode. Both l-CAg@Au and d-CAg@Au exhibited outstanding photothermal conversion compared to the core–shell structure without amino acids (Ag@Au). d-CAg@Au possessed the best photothermal conversion efficiency (87.28%) among the composite nanoparticles. The antitumor therapeutic efficacy of as-prepared samples was evaluated in vitro and in vivo, and apoptosis analysis was done via flow cytometry. This work reports novel insights for the preparation of special bimetallic branched structures and broadens the application of metal nanomaterials in photothermal tumor therapy.
研究领域:
纳米技术
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生物医学工程
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癌症研究
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材料科学
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治疗学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
·
IF 5.7
Jinyan Gu,Lianzhu Lin,Mouming Zhao
Due to the difficulty in obtaining highly branched rhamnogalacturonan-I (RG-I) type pectin, the relationship between the extent of RG-I branching (EB) of pectin and prebiotic/immunomodulatory activity has not been systematically investigated. Moreover, it is only possible to establish a structure–activity relationship using pectin that is highly purified and accurately characterized. In this study, a homogeneous highly branched RG-I type pectin (LBP-P4, a final product) with dual proliferative effects on Bifidobacterium and macrophage was effectively purified for the first time using enzyme hydrolysis combined with ultrafiltration. The RG-I content and EB of LBP-P4 reached 97.32 and 77.12, respectively. Its two branches were composed of arabinan and arabinogalactan-II, containing → 5)-Araf-(1→, →3)-Araf-(1→, →3,6)-Galp-(1→ and →6)-Galp-(1→ residues). The structure–activity relationship analysis indicated that strong prebiotic/immunomodulatory activity of LBP-P4 was depended on its high EB, which was further confirmed by the molecular docking simulation between low/high branched pectin with β-1,6-galactosidase, α-l-arabinanase, and Toll-like receptor 4 (TLR4).
研究领域:
食品科学
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生物化学
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免疫学
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微生物学
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药学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）