製備含高抗污功能性共聚高分子及探討其塗佈於基材表面之抗生物沾黏性質

Preparation of Ultra-high Antifouling Copolymers and Investigation of Anti-bioadhesive Properties on thier Coated Substrate Interfaces

楊惠珊(Hui-Shan Yang)

指導教授 ： 張雍

中原大學/工學院/化學工程研究所/碩士(2013年)

https://doi.org/10.6840/cycu201300635

摘要

本論文內容主要分為三個子題，研究主軸為合成製備不同分子結構之高抗污功能性共聚高分子，並以疏水或靜電作為驅動力於不同基材上產生分子自組裝，使改質後之基材表面具抗生物分子沾黏性質。本研究中，設計三種抗生物分子沾黏之共聚高分子系統，並分別進行系統性研究探討。
論文第一部份，以原子轉移自由基聚合法製備含疏水性鏈段的兩性離子型雙嵌段共聚高分子(poly(propylene oxide)-block-poly(sulfobetaine methacrylate), PPO-b-PSBMA)，藉由高分子與基材表面之分子間疏水作用力，固定PPO-b-PSBMA於疏水基材表面上，並進一步探討其抗菌性質的表現。本研究中，製備出三種不同物理結構的疏水表面 (CH3- self-aseembled monolayers (surface-1), coated layers polystyrene particals (surface-2), and porous polystyrene films (surface-3)) 為基材，分別塗佈上不同鏈段比例的PPO-b-PSBMA 共聚高分子 (PPO20-b-PSBMA10、PPO20-b-PSBMA20、PPO20-b-PSBMA40)，其材料表面之物理結構由原子力顯微鏡 (AFM) 及掃描式電子顯微鏡 (SEM) 來進行觀察，而材料表面之化學性質由表面接觸角量測儀 (CA) 及表面化學分析儀 (XPS) 來做鑑定。微生物貼附情形以螢光顯微鏡來觀察，並探討對於不同鏈段比例的PPO-b-PSBMA共聚高分子於不同粗糙度的基材表面所產生之抗微生物貼附性質。研究結果顯示，可利用PPO之疏水片段使共聚高分子與材料表面結合，隨著基材上的PSBMA兩性離子鏈段長度增加，會降低微生物於基材表面沾黏的比例，並具有高度抵抗不同細菌貼附的效果。
論文第二部份，以原子轉移自由基聚合法製備含甲基丙烯酸聚乙二醇酯之雙親性雙團聯共聚嵌段高分子 (poly(styrene-block-poly(ethylene glycol) methacrylate); PS-b-PEGMA)，改質疏水性之聚氟乙二烯 (PVDF) 多孔薄膜，來提升其PVDF膜材表面之抗蛋白質吸附性質。本研究製備一系列不同親疏水鏈段之雙嵌段共聚高分子，PS-b-PEGMA分子結構設計以五種不同PS/PEGMA親疏水鏈段比例 (1.0~6.0)，但固定疏水鏈段PS分子量 (~6.0kDa)，所製備出之共聚嵌段高分子包含: PS57-b-PEGMA9、PS57-b-PEGMA13、PS57-b-PEGMA17、PS57-b-PEGMA29、PS57-b-PEGMA57，透過疏水性作用力於膜材表面進行分子自組裝進而將PS-b-PEGMA高分子固定於PVDF膜材表面上。實驗結果顯示，膜材表面隨著PS-b-PEGMA共聚高分子塗佈量增加接觸角隨之降低，顯示此方式能將疏水性材料快速為親水化，然而不同親水鏈長的PEGMA會影響抵抗蛋白質以及細菌貼附的結果，在穩定性測試方面，此共聚高分子可自組裝在膜材上並不會因為薄膜經過去離子水沖洗而降低薄膜效能，並且其中以PS57-b-PEGMA25 (PS/PEGMA=2) 高分子抵抗細菌貼附效果最為顯著。
論文第三部份，以Michael Addition來製備含Poly(ethylene glycol) methyl ether methacrylate (PEGMA)、3-Sulfopropyl methacrylate potassium salt (SA)、Sulfobetaine Methacrylate (SBMA) 之三種帶電荷共聚高分子PEI-PEGMA、PEI-SA、PEI-SBMA，並將其以靜電吸附方式塗佈於氫氧基磷灰石 (hydroxyapatite, HA) 基材表面，探討其對抗菌性質的影響。以核磁共振光譜儀 (NMR) 與表面化學分析儀 (XPS) 來鑑定共聚高分子之化學組成，並使用微量光譜分析儀針對高分子吸附於材料的結果進行定量分析。使用共軛焦雷射掃瞄式電子顯微鏡 (Confocal Laser Scanning Microscopy) 來觀察後續的細菌貼附於材料上的程度，以探討對於不同電荷之共聚高分子PEI、PEI-PEGMA、PEI-SA、PEI-SBMA抵抗細菌貼附的能力。實驗結果顯示，氫氧基磷灰石以及人牙塗佈條件於PEI-SBMA的高分子溶液濃度為5mg/mL時，抗蛋白質吸附的效果最佳。因此，以此最佳條件進行不同種類細菌貼附實驗，基材抗菌效果較未改質基材為優異。由細菌貼附測試的結果顯示帶有兩性離子基團之共聚高分子 (PEI-SBMA) 具有高度抗不同蛋白以及細菌貼附的特性。

關鍵字

原子轉移自由基聚合法 ； 抗污高分子 ； 抗生物分子沾黏

並列摘要

The conthent of this thesis includes three sub-topics. The research target aims to design new formulation of copolymers and form a substrate suface with highly anti-bioadhesive property via hydrophobic- or electrostatic-driven self-assembled coating. In this study, we design three types of anti-fouling copolymer systems, and introduce a systematic investigation.
In the first part of this thesis, zwitterionic diblock copolymers containing hydrophobic propylene oxide and hydrophilic sulfobetaine methacrylate blocks were prepared with well controlled molecular weights via atom-transfer radical polymerization (ATRP). Poly(propylene oxide)-block-poly(sulfobetaine methacrylate) (PPO-b-PSBMA) copolymers with varying zwitterionic PSBMA lengths were self-assembly coated onto three diffent surfaces of CH3- self-aseembled monolayers (surface-1),polystyrene particals coated layers (surface-2), and porous polystyrene films (surface-3) for enhancing surface hydrophilicity and bacterial resistance. The chemical composition and microstructure of the surface-modified substrates were characterized by Fourier transform infrared spectroscopy (FT-IR), contact angle, atomic force microscopy (AFM) measurements, and scanning electron microscopy (SEM). Deferent bacterial adhesion was observed by fluorescence microscopy. It was found that the increase of the PSBMA chain length coated on the substrate resulting in the decrease of bacterial attachment. Thus, copolymers containing zwitterionic groups are ideal for highly resisting bacterial adhesion when the surface coverage of zwitterionic groups is well controlled.
In the second part of this thesis, a systematic group of hyper-brush PEGylated diblock copolymers containing poly(ethylene glycol) methacrylate (PEGMA) and polystyrene (PS) was synthesized using an atom transfer radical polymerization (ATRP) method and varying PEGMA lengths. This study demonstrates the anti-biofouling membrane surfaces by self-assembled anchoring PEGylated diblock copolymers of PS-b-PEGMA (PS57-b-PEGMA9, PS57-b-PEGMA17, PS57-b-PEGMA13, PS57-b-PEGMA29, and PS57-b-PEGMA57) on the microporouss poly(vinylidene fluoride) (PVDF) membrane. A set of copolymers are used to modify the PVDF surface, PS-b-PEGMA with five different PS/PEGMA molar ratios in a range from 1.0 to 6.0 but the same PS molecular weights (MWs , 6.0 kDa). In the results, the contact angle decreased with the increasing amounts of PS-b-PEGMA copolymer on the surface. It was found that the increased chain length of hydrophilic block of PEGMA reduces the bacterial attachment, and the PS57-b-PEGMA29 copolymer shows the best ability.
In the third part of this thesis, a set of new functionalized polyethyleneimine (PEI) copolymers, including a neutral PEGylated copolymer PEI-PEGMA, a negatively charged copolymer PEI-SA and a zwitterionic copolymer PEI-SBMA, and their use as anti-biofouling coating agent for human teeth protection. Polymers were synthesized by Michael addition and structures assessed by 1H NMR. Zeta-potential measurements permitted to evaluate the net charge carried by the copolymer. XPS analysis revealed that each copolymer could be efficiently coated onto hydroxyapatite, a ceramic material used as a model tooth. Copolymers carrying an overall negative net charge were more efficiently adsorbed. It was attributed to the establishment of electrostatic interactions with calcium ions. Protein adsorption tests revealed that two factors were important in the reduction of protein adsorption. Indeed, both the surface charge and the surface ability to bind and entrap water molecules have to be considered. PEI-SBMA, which zeta potential in PBS solution was found to be negative, was therefore efficient to inhibit the adsorption of BSA, a negative protein. On the other hand, it also resisted the adsorption of lysozyme, a positive protein, since zwitterionic molecules can easily entrap water and provide a very hydrophilic environment. Streptococcus mutans attachment tests performed revealed that all copolymers were efficient to resist this type of bacteria responsible for dental carries. Best results were also obtained with PEI-SBMA coating. This copolymer was also shown to efficiently resist the adsorption of positively charged bacteria (Stenotrophomonas maltophilia). Tests performed on real human tooth showed that PEI-SBMA could inhibit up to 70% of bacteria adhesion, which constitutes a major result considering that surface of teeth is very rough, therefore physically promoting the attachment of proteins and bacteria.

並列關鍵字

anti-fouling ； bacteria ； copolymer ； ATRP

參考文獻

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