Thermo-responsive random copolymers,poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-(ethylene glycol)methyl ether methacrylate)(P(EO_(2)-co-EO_(4/5)))and poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-ethylen...Thermo-responsive random copolymers,poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-(ethylene glycol)methyl ether methacrylate)(P(EO_(2)-co-EO_(4/5)))and poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-ethylene glycol methacrylate(P(EO2-co-EG4/5))are synthesized via atom transfer radical polymerization(ATRP).The successful synthesis and the narrow polydispersity index(PDI)of two copolymers are indicated by 1H nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)analyses.The transition behaviors of polymers in the aqueous solution are demonstrated by changes in turbidity and particle sizes.The transition behavior of P(EO2-co-EG4/5)is found to be milder than that of P(EO2-co-EO4/5).Moreover,the presence of hydrogen bonds without thermo-responsive properties established by hydroxyl groups in the end-side chain of P(EO_(2)-co-EG_(4/5))hinders the dehydration at the transition temperature(TT).Attenuated total reflection Fourier transform infrared spectrometry(ATR-FTIR)analysis along with contact angle measurements reveals that both P(EO_(2)-co-EO_(4/5))and P(EO_(2)-co-EG_(4/5))films undergo phase transitions from hydrophilicity to hydrophobicity above TT.By examining the swelling and collapse behaviors of the polymer films during phase transitions,it can be concluded that the end hydroxyl groups may establish hydrogen bonds with neighboring ether groups within the films,which remain intact throughout the phase transition process due to their strong bonding interactions.This leads to an increase in steric hindrance within swollen films thereby impeding dehydration processes and inducing hysteresis during phase transitions.展开更多
基金Fujian External Cooperation project of Natural Science Foundation,China(No.2022I0042)。
文摘Thermo-responsive random copolymers,poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-(ethylene glycol)methyl ether methacrylate)(P(EO_(2)-co-EO_(4/5)))and poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-ethylene glycol methacrylate(P(EO2-co-EG4/5))are synthesized via atom transfer radical polymerization(ATRP).The successful synthesis and the narrow polydispersity index(PDI)of two copolymers are indicated by 1H nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)analyses.The transition behaviors of polymers in the aqueous solution are demonstrated by changes in turbidity and particle sizes.The transition behavior of P(EO2-co-EG4/5)is found to be milder than that of P(EO2-co-EO4/5).Moreover,the presence of hydrogen bonds without thermo-responsive properties established by hydroxyl groups in the end-side chain of P(EO_(2)-co-EG_(4/5))hinders the dehydration at the transition temperature(TT).Attenuated total reflection Fourier transform infrared spectrometry(ATR-FTIR)analysis along with contact angle measurements reveals that both P(EO_(2)-co-EO_(4/5))and P(EO_(2)-co-EG_(4/5))films undergo phase transitions from hydrophilicity to hydrophobicity above TT.By examining the swelling and collapse behaviors of the polymer films during phase transitions,it can be concluded that the end hydroxyl groups may establish hydrogen bonds with neighboring ether groups within the films,which remain intact throughout the phase transition process due to their strong bonding interactions.This leads to an increase in steric hindrance within swollen films thereby impeding dehydration processes and inducing hysteresis during phase transitions.
文摘目的 探讨贮存时间对红细胞非典型趋化因子受体1(atypical chemokine receptor 1,ACKR1)的趋化因子清除功能及储存的影响。方法 6袋去白细胞悬浮红细胞制剂,每袋通过无菌热合机分出2小袋(10 mL/袋),置于血液贮存冰箱储存,分别于贮存d5、d25取出,进行红细胞CCL5、CXCL8以及CCL11含量以及ACKR1趋化因子清除功能测定。同时采集贮存期在d5~25的42份(1 mL/份)去白细胞悬浮红细胞制剂标本,进行红细胞膜上ACKR1表达及趋化因子CCL5、CXCL8以及CCL11含量的检测。结果 贮存期d 25和d 5相比,红细胞裂解液CCL5(pg/mL)(467.7±250.2 vs 586.9±209.5,P>0.05)及CCL11(pg/mL)(122.2±30.3 vs 125.5±32.7,P>0.05)浓度无差异,而CXCL8的浓度降低(pg/mL)(42.4±5.3 vs 24.3±5.9,P<0.05),红细胞ACKR1对趋化因子CCL5(pg/mL)(2 634.0±730.2 vs 453.8±257.4,P<0.05)、CXCL8(pg/mL)(1 117.0±236.6 vs 306.2±28.3,P<0.05)以及CCL11(pg/mL)的清除能力下降(1 278.0±164.5 vs 467.2±50.9,P<0.05)。在红细胞膜表面未检出趋化因子CCL5、CXCL8以及CCL11。红细胞表面ACKR1表达在d 5~25期间,无明显变化(P>0.05)。结论 红细胞内是贮存ACKR1结合趋化因子主要场所,在红细胞贮存期会发生红细胞ACKR1趋化因子清除功能的降低以及红细胞内部储存的某些ACKR1结合趋化因子的降低。
