接枝不同官能团的聚酯材料对血小板黏附及其功能的影响研究

The impact of PBT membranegrafting with functional groups on platelet adhesion and platelet function

目的考察接枝不同官能团(-COOH、-OH、两性基团)的聚对苯二甲酸丁二醇酯(PBT)膜对血小板黏附及血小板功能的影响,选择适用于过滤去除浓缩血小板中白细胞的材料。方法利用紫外改性的方法,将不同单体包括丙烯酸(AA)、丙烯酸羟乙酯(HEA)和N-(3-磺丙基)-N-甲基丙烯酸基氧乙基-N,N-二甲基铵内铵盐(SMDB)接枝到PBT表面,得到接枝不同官能团的PBT膜,包括PBT-AA(-COOH)、PBT-HEA(-OH)、PBT-SMDB(两性基团);通过傅里叶红外光谱、水接触角及表面粗糙度等指标对改性PBT的理化性能做表征,采用扫描电镜观察改性PBT对血小板的黏附,并通过检测PBT改性前后的血小板聚集率、低渗休克相对变化、CD62p表达率等指标,考察改性PBT对血小板功能的影响。结果在红外光谱的1 047和1 043 cm-1处出现了C-O-C的弯曲振动峰和O=S=O的对称伸缩振动峰,提示HEA和SMDB接枝到了PBT膜表面。扫描电镜显示:未改性的PBT膜表面黏附的血小板数明显多于改性PBT膜表面,且可以观察到明显的伪足。血小板黏附数在接枝不同官能团的PBT膜表面顺序为:-COOH>两性基团>-OH。未改性PBT组(n=6)与对照组(未接触材料的血小板)(n=6)比较:血小板最大聚集率(%)为87.22±2.10 vs 82.36±2.11,低渗休克相对变化率(%)为79.33±1.27 vs 77.12±1.09,CD62p表达率增加(%)为9.78±0.58 vs 17.45±1.25(P<0.05)。在接枝不同官能团的改性PBT膜中,PBT-HEA(n=6)对血小板聚集和血小板活化等功能影响最小[血小板最大聚集率(93.34±1.45)%、血小板低渗休克相对变化率(81.26±1.48)%、CD62p表达率(12.51±0.85)%]。结论表面接枝HEA的聚酯对血小板的黏附及功能影响明显小于接枝其他官能团的材料,或可作为用于浓缩血小板过滤去除白细胞的新材料。

Objective To evaluate the effects of polybutylene terephthalate （PBT） membrane grafting with different functional groups（-COOH,-OH and zwitterionic sulfobetaine group） on plateletadhesion and platelet function, and select suitable filter material for depletion leukocyte from platelet concentrations（PCs）. Methods PBT-AA（- COOH） , PBT-HE- MA（-OH）, PBT-SMDB（ zwitterionic sulfobetaine groups） membranesobtained by UV radiation with monomers including a- crylic acid （ AA）, hydroxyethyl acrylate （ HEA）, N- （3-sulfopropyl） -N-methacroyloxyethyl-N, N-dimethylammonium betaine （SMDB）. The physical and chemical properties of modified PBT was characterized by attenuated total reflectance-Fourier transform infrared spectra（ FITR）, water contact angle, zeta potential and surface roughness. Platelet adhesion was observed by SEM, and platelet aggregation, platelet hypotonic shock rate （HSR） and platelet activation （expression of CD62P ） were investigated.Results The new absorption at 1 047 cm-1 was ascribed to symmetric and antisymmetric C-O-C stretching vi- bration of HEA, and 1 043 cm^-1 was belonged to asymmetric O = S = O stretching vibration of SMDB, which was confirmed that HEA and SMDB had been grafted on the surface of PBT successfully. SEM results showed that PBT adhered much more platelet than other modified membranes, and protrusions of platelet was obvious. The number of platelet adhesion to mem- brane decreased in the order： the surface bearing COOH 〉the surface bearing sulfobetaine group 〉 the surface bearing OH. Furthermore, compared with the native control（ n = 6）, the max platelet aggregation ratio （%） （control vs PBT was 87.22± 2. 10 vs 82. 36±2. 11 ,P〈0.05） and HSR（%） （control vs PBT was 79. 33±1.27 vs 77. 12±1.09,P〈0. 05） decreased, and CD62p（%） positive expression rate （control vs PBT was 9.78±0. 58 vs 17.45±1.25,P〈0. 05） increased significantly. A- mong the modified PBT membranes, PBT-HEA （n= 6）almost had no impact on platelet function[ max platelet aggregation ratio was （93.34± 1.45）%, HSR was （81.26± 1.48）%, CD62p positive expression rate was （12.51 ± 0.85）%]. Conclusions PBT-HEA adhered minimal platelet and has little impact on platelet function, which is expected to be used as a new material for the removal of leukocyte frorfi PCs.