Materials Research Express
·
2019
·Vol. 6
·期 8
·085711
·
IF 1.449
Shichao Zhao,Hongyu Zhu,Zhaoming Chen,Shirong Shuai,Ning Zhang,Yu Liu,Zikun Rao,Yang Li,Cong Zhao,Kanghong Zhou,Wei Ge,Jianyuan Hao
Stimuli-responsive polypeptide hydrogel has attracted a great deal of interests because of the biodegradability, biocompatibility and the response-ability to external stimuli. Here we synthesized triblock copolymers methoxy-poly (ethylene glycols)-b-poly (L-lysine)-b-poly (L-valine) (mPEG-PLysx-PVy) by sequential ring opening polymerization. Through adjusting the length of hydrophilic and hydrophobic segments, we constructed a temperature- and pH- responsive hydrogel system using polymer mPEG-PLys2-PV7. The phase diagram from test tube inversion method showed that the gel transition temperature could cover the body temperature (37 °C) and decreased with the elevated pH value. TEM and FTIR measurements proved that the secondary structure of the polymer solution was mainly β–sheet structure, and the sol-gel transition process was caused by both the dehydration of mPEG and the change of the secondary structure. After loading DOX in hydrogels, we investigated the drug release behavior in vitro at different pH values. The results showed that the drug release at pH5.5 was faster than that at pH 7.4. About 36% and 100% of loaded drug was respectively released from hydrogels at 37 °C within 48 h at pH 7.4 and pH 5.7. This polypeptide hydrogel material might be used as drug targeting release system and does not affect normal tissues due to its significant pH sensitivity.
研究领域:
生物材料学
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高分子化学
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药剂学
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DOI
高影响因子
Chemistry-An Asian Journal
·
2023
·Vol. 18
·期 8
·e202300021
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IF 4.1
Zhiqiang Lin,Junfeng Ding,Xuesi Chen,Chaoliang He
Graphical pH- and temperature-responsive monomethoxy poly(ethylene glycol) (mPEG)-polypeptide hydrogels were synthesized using ring-opening polymerization and post-polymerization modification. Aqueous solutions of the mPEG-polypeptides exhibited α-helix-to-β-sheet transitions when the pH was increased from 6.5 to 7.0, leading to a marked reduction in gelation concentration and prolonged drug release profiles at neutral pH. pH- and temperature-responsive hydrogels have attracted considerable attention due to their responsiveness to dual physiologically-relevant stimuli. In this study, we developed stimuli-responsive hydrogels based on monomethoxy poly(ethylene glycol) (mPEG)-polypeptide block copolymers containing various tertiary amine pendants (EEP-TAs). The EEP-TAs were synthesized via ring-opening copolymerization of α-amino acid N -carboxyanhydrides, and further modified post-polymerization with click chemistry. The EEP-TAs exhibited an α-helix-to-β-sheet transition when the pH was increased from 4.0 to 7.4. At elevated polymer concentrations, aqueous solutions of the EEP-TAs underwent thermo-induced sol–gel phase transitions, which were dependent on the pH. The hydrogels almost fully degraded within 3 weeks in the subcutaneous layer of mice and exhibited good histocompatibility in vivo. Additionally, doxorubicin (DOX)-loaded hydrogels exhibited pH-responsive drug release profiles in vitro, which were composed of rapid release at acidic pH and more sustained release at neutral pH. Thus, these polypeptide hydrogels hold potential as depots for environment-responsive delivery of therapeutic agents.
研究领域:
生物材料
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药剂学
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高分子化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2012
·Vol. 50
·期 9
·1834-1843
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IF 3.919
Ye Liao,Chang-Ming Dong
Thermosensitive diethylene glycol-derived poly( L -glutamate) homopolypeptides (i.e., poly- L -EG 2 -Glu) with different molecular weights (MW) ( M n,GPC = 5380–32520) were synthesized via the ring-opening polymerization (ROP) of EG 2 - L -glutamate N -carboxyanhydride (EG 2 -Glu-NCA) in N , N -dimethylformamide solution at 50 °C. Their molecular structure, conformation transition, liquid crystal (LC) phase behavior, lower critical solution temperature (LCST) transition, and morphology evolution were thoroughly characterized by means of FTIR, 1 H NMR, gel permeation chromatography, differential scanning calorimetry, wide angle X-ray diffraction, polarized optical microscope, transmission electron microscope, and dynamic light scattering. In solid state, the homopolypeptide poly- L -EG 2 -Glu presented a conformation transition from α-helix to β-sheet with increasing their MW at room temperature, while it mainly assumed an α-helix of 80–86% in aqueous solution. Poly- L -EG 2 -Glu showed a thermotropic LC phase with a transition temperature of about 100 °C in solid state, while it gave a reversible LCST transition of 34–36 °C in aqueous solution. The amphiphilic homopolypeptide poly- L -EG 2 -Glu self-assembled into nanostructures in aqueous solution, and their critical aggregation concentrations decreased with increasing MW. Interestingly, their morphology changed from spherical micelles to worm-like micelles, then to fiber micelles with increasing MW. This work provides a simple method for the generation of different nanostructures from a thermosensitive biodegradable homopolypeptide. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
研究领域:
高分子化学
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材料科学
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生物材料
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产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2014
·Vol. 216
·期 2
·196-204
·
IF 2.451
Qiulin Yuan,Dan Liu,Yong Deng,Ying Ling,Haoyu Tang
A series of liquid-crystalline 4-alkyloxybiphenyl-poly(γ-propyl- l -glutamate) conjugates (PPLG n -g-BPC m , n = 10, 54, 110, and 274, m = 4, 6, and 12) with end-on biphenyl mesogens and variable alkyl tails is synthesized via a facile copper-mediated alkyne–azide [2+3] 1,3-dipolar cycloaddition. 1 H NMR and FTIR analyses reveal a quantitative conjugation efficiency for each sample. Variable-temperature FTIR results indicate an irreversible α-helical to β-sheet transition of the PPLG 10 -g-BPC 6 in the solid state, whereas PPLG n -g-BPC m samples with a longer main-chain length ( n ≥ 54) only adopt an α-helical conformation in the temperature range between 25 and 200 °C. DSC, polarized optical microscopy (POM), and wide-angle X-ray scattering (WAXS) results collectively reveal that the PPLG n -g-BPC m samples undergo a reversible crystalline to liquid-crystalline phase transition depending on the main-/side-chain lengths. The PPLG n -g-BPC m ( n ≥ 54, m ≤ 6) samples form highly stable smectic (SmC or SmE) phases with a calculated tilt angle of 73–90°.
研究领域:
材料科学
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生物化学
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产品关联
DOI
高影响因子
Regenerative Biomaterials
·
2022
·
IF 5.763
Li Zhongcheng,Ren Qian,Han Sili,Ding Longjiang,Qin Xi,Hu Die,He Ting,Tian Tian,Lu Ziqian,Zhang Linglin
Recently, a de novo synthetic calcium-responsive self-assembly β-sheet peptide ID8 (Ile-Asp-Ile-Asp-Ile-Asp-Ile-Asp) has been developed to serve as the template inducing hydroxyapatite nucleation. The aim of this study was to evaluate the effect of ID8 on intrafibrillar mineralization of collagen making full use of its self-assembly ability. The mineralization experiments were carried out in vitro on both bare Type I collagen and fully demineralized dentin samples. The calcium-responsive self-assembly of ID8 was revealed by circular dichroism spectrum, 8-anilino-1-naphthalenesulfonic acid ammonium salt hydrate assay, attenuated total reflection Fourier transform infrared spectrum (ATR-FTIR) and transmission electron microscope (TEM). Polyacrylic acid (450 kDa) with a concentration of 100 μg ml−1 was selected as the nucleation inhibitor based on the determination of turbidimetry and TEM with selected area electron diffraction (TEM-SAED). The results showed that collagen intrafibrillar mineralization was significantly promoted with the pretreatment of self-assembly ID8 detected by TEM-SAED, SEM, X-ray diffraction and ATR-FTIR. The pretreatment of collagen utilizing self-assembly ID8 not only enhanced intermolecular hydrogen bonding but also contributed to calcium retention inside collagen and significantly increased the hydrophilicity of collagen. These results indicated that peptides with self-assembly properties like ID8 are expected to be potential tools for biomimetic mineralization of collagen.
研究领域:
生物材料
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材料科学
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生物矿化
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产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2024
·
IF 6
Yan Zhang,Yuyang Liu,Wannan Li,Weiwei Han
Antioxidant peptides can be obtained from diverse dietary protein sources with high safety. The Kelch-like ECH-associated protein 1(Keap1) is a key protein in the cellular oxidative stress signaling pathway and it plays an important role in the field of antioxidant. Soybeans are a vital source for the production of bioactive peptides. In this study, firstly, we screened 468 antioxidant peptides from soybean protein with low molecular weight, high hydrophobicity and non-toxicity. The top three antioxidant peptides were isolated and extracted from the fractions using UHPLC-QQQ/MS analysis. The free radical scavenging rate demonstrated significant antioxidant activity of PHHADS (EC 50 = 4.26 mmol/L). In addition, peptide PHHADS was demonstrated significantly protects HepG2 cells from oxidative stress-induced damage. Lastly, 200 ns molecular dynamics simulations were performed between the peptides and Keap1. The results revealed that PHHADS closely interacts with the active site of Keap1. Moreover, the interaction of the antioxidant peptides with Keap1 led to the disruption of the β-sheet structure of Keap1 in residues380-390, transforming into an irregularly curved structure. This particular region in Keap1 is crucial for substrates binding, suggesting a potential inhibitory mechanism by the peptides. These findings contribute to the understanding of antioxidant peptide interactions and their potential application in developing functional foods for health benefits.
研究领域:
食品科学
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生物化学
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分子生物学
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药理学
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产品关联
DOI
高影响因子
Protein & Cell
·
2020
·Vol. 11
·期 4
·267-285
·
IF 10.164
Xu Gang,Ding Zhaozhao,Lu Qiang,Zhang Xiaoyi,Zhou Xiaozhong,Xiao Liying,Lu Guozhong,Kaplan David L
Gradient biomaterials are considered as preferable matrices for tissue engineering due to better simulation of native tissues. The introduction of gradient cues usually needs special equipment and complex process but is only effective to limited biomaterials. Incorporation of multiple gradients in the hydrogels remains challenges. Here, beta-sheet rich silk nanofibers (BSNF) were used as building blocks to introduce multiple gradients into different hydrogel systems through the joint action of crosslinking and electric field. The blocks migrated to the anode along the electric field and gradually stagnated due to the solution-hydrogel transition of the systems, finally achieving gradient distribution of the blocks in the formed hydrogels. The gradient distribution of the blocks could be tuned easily through changing different factors such as solution viscosity, which resulted in highly tunable gradient of mechanical cues. The blocks were also aligned under the electric field, endowing orientation gradient simultaneously. Different cargos could be loaded on the blocks and form gradient cues through the same crosslinking-electric field strategy. The building blocks could be introduced to various hydrogels such as Gelatin and NIPAM, indicating the universality. Complex niches with multiple gradient cues could be achieved through the strategy. Silk-based hydrogels with suitable mechanical gradients were fabricated to control the osteogenesis and chondrogenesis. Chondrogenic-osteogenic gradient transition was obtained, which stimulated the ectopic osteochondral tissue regeneration in vivo. The versatility and highly controllability of the strategy as well as multifunction of the building blocks reveal the applicability in complex tissue engineering and various interfacial tissues.
研究领域:
生物材料科学
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组织工程
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2019
·Vol. 10
·期 1
·1-11
·
IF 11.878
Zong Yu,Fang Fang,Meyer Kirsten J.,Wang Liguo,Ni Zhihao,Gao Hongying,Lewis Kim,Zhang Jingren,Rao Yu
Teixobactin represents a new class of antibiotics with novel structure and excellent activity against Gram-positive pathogens and Mycobacterium tuberculosis . Herein, we report a one-pot reaction to conveniently construct the key building block l -allo-Enduracidine in 30-gram scale in just one hour and a convergent strategy (3 + 2 + 6) to accomplish a gram-scale total synthesis of teixobactin. Several analogs are described, with 20 and 26 identified as the most efficacious analogs with 3~8-fold and 2~4-fold greater potency against vancomycin resistant Enterococcus faecalis and methicillin-resistant Staphylococcus aureus respectively in comparison with teixobactin. In addition, they show high efficiency in Streptococcus pneumoniae septicemia mouse model and neutropenic mouse thigh infection model using methicillin-resistant Staphylococcus aureus . We also propose that the antiparallel β-sheet of teixobactin is important for its bioactivity and an antiparallel dimer of teixobactin is the minimal binding unit for lipid II via key amino acids variations and molecular docking.
研究领域:
药物化学
·
微生物学
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有机合成
·
分子生物学
✓ 已验证
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2022
·
IF 7.425
Xuan Huang,Chunjun Yan,Ming Lin,Changwei He,Yanfei Xu,Yukun Huang,Zheng Zhou
Alkaline-extracted walnut protein isolate (AWPI) shows poor solubility in aqueous solutions, resulting in relatively low emulsion capacity. This work investigated the influence of ellagic acid (EA) or epigallocatechin-3-gallate (EGCG) conjugation on the solubility and emulsifying properties of AWPI. The increase in polyphenol content and decrease in free amino and thiol groups of walnut proteins confirmed successful conjugation. AWPI polyphenol conjugates showed significantly reduced surface hydrophobicity, greatly enhanced surface charge, and consequently improved solubility. Circular dichroism (CD) results indicated that the polyphenol-conjugated AWPI contained relatively higher α-helical and lower β-sheet contents than AWPI. The antioxidant capacity of the polyphenol-conjugated AWPI was significantly enhanced. Additionally, polyphenol conjugation resulted in decreased mean particle sizes and increased surface charges of the walnut protein-covered oil droplets. The emulsions stabilized by AWPI-polyphenol conjugates were relatively more stable over a range of pH values (7.0–11.0) and thermal treatments (25 °C–90 °C). Moreover, they exhibited greater storage stability than those stabilized by unmodified AWPI.
研究领域:
食品科学
·
化学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2024
·
IF 6
Meiyu Gu,Jiahui Shi,Boya Zhang,Xibo Wang,Xu Wang
The effect of covalent binding of different concentrations of hydroxytyrosol (HT) to soy protein isolate (SPI) by enzymatic method on the structure and function of the complex was investigated. Polyphenol binding rate increased and then decreased with increasing hydroxytyrosol concentration, with a maximum binding rate of 38.10 ± 1.08%. Covalent binding to HT resulted in a significant increase in the turbidity of the adduct and a significant decrease in the free sulfhydryl content and surface hydrophobicity. The structure of the adduct was altered and the α-helix structure was converted to a β-sheet one. The maximum foaming property of the adducts was observed at a HT concentration of 40 μmol/g, which was 28.84% higher than the control SPI. The adduct had maximum solubility (52.84 ± 0.18%) at HT concentration of 50 μmol/g. The emulsifying properties of the adducts were maximized at a hydroxytyrosol concentration of 60 μmol/g. When the HT concentration was 70 μmol/g, the DPPH and ABTS radical scavenging rates of the adducts were increased by 245.03% and 26.35%, respectively, compared with the control SPI.
研究领域:
食品科学
·
蛋白质化学
·
生物技术
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Rourou Zhang,An Ding,Xuejun Cai,Langming Bai,Guibai Li,Heng Liang,Chuyang Y. Tang
Widespread outbreaks of threatening infections caused by unknown pathogens and water transmission have spawned the development of adsorption methods for pathogen elimination. We proposed a biochar functionalization strategy involving ε-polylysine (PLL), a bio-macromolecular poly(amino acid)s with variable folding conformations, as a "pathogen gripper" on biochar. PLL was successfully bridged onto biochar via polydopamine (PDA) crosslinking. The extension of electropositive side chains within PLL enables the capture of both nanoscale viruses and micrometer-scale bacteria in water, achieving excellent removal performances. This functionalized biochar was tentatively incorporated into ultrafiltration (UF) system, to achieve effective and controllable adsorption and retention of pathogens, and to realize the transfer of pathogens from membrane surface/pore to biochar surface as well as flushing water. The biochar-amended UF systems presents complete retention (∼7 LRV) and hydraulic elution of pathogens into membrane flushing water. Improvements in removal of organics and anti-fouling capability were observed, indicating the broken trade-off in UF pathogen removal dependent on irreversible fouling. Chemical characterizations revealed adsorption mechanisms encompassing electrostatic/hydrophobic interactions, pore filling, electron transfer, chemical bonding and secondary structure transitions. Microscopic and mechanical analyses validated the mechanisms for rapid adsorption and pathogen lysis. Low-concentration alkaline solution for used biochar regeneration, facilitated the deprotonation and transformation of PLL side chain to folded structures (α-helix/β-sheet). Biochar regeneration process also promoted the effective detachment/inactivation of pathogens and protection of functional groups on biochar, corroborated by physicochemical inspection and molecular dynamics simulation. The foldability of poly(amino acid)s acting like dynamic arms, significantly contributed to pathogen capture/desorption/inactivation and biochar regeneration. This study also inspires future investigation for performances of UF systems amended by poly(amino acid)s-functionalized biochar under diverse pressure, temperature, reactive oxygen species of feeds and chemical cleaning solutions, with far-reaching implications for public health, environmental applications of biochar, and UF process improvement.
研究领域:
环境工程
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水处理
·
材料科学
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生物技术
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）