在生醫金屬植入物中，鈦以及合金因為具有相對良好的生物相容性，良好的機械性質及抗腐蝕性而被廣泛使用取代傳統的不鏽鋼及鈷合金。但是，臨床上發現鈦基材有血液相容性、蛋白質易吸附以及骨整合時間過長等問題。本實驗為促進鈦以及合金之醫療植入物在人體內的生物相容性以及促進骨整合，透過合成多功能性共聚物以達到改植及促進相容性的目的。該共聚物含有具生物相容性，利於細胞貼附生長的羧基；6-acryloyloxyhexanoic acid 以及含亞磷酸官能基作為金屬表面錨定基團的11-Acryloyloxy Undecyl Phosphonic Acid (AcrUPA)。將此兩種單體聚合得到新的共聚物以修飾鈦金屬表面，希望可以提供鈦金屬植入物改良的一個方向。
在研究中透過NMR、TGA、GPC對共聚物進行組成及基本性質分析。確認共聚物已成功合成便使用旋轉塗佈的方式將共聚物均勻塗佈於鈦基材並進行加熱以利亞磷酸根與氧化鈦表面產生化學鍵結反應，使用靜態接觸角(Static water contact angle measurement)、Atomic force microscopy (AFM)、X-ray photoelectron spectroscopy (XPS)等分析改質層表面的親疏水性，改質層的穩定度，粗糙度以及元素組成以確認改質層的品質。
本實驗透過GPC分子量的測量發現；兩種單體因為親疏水性不同，加上6-acryloyloxyhexanoic acid傾向自我聚集導致共聚物分子量不夠高。但改變旋轉塗佈的條件並經由各種表面分析的檢測發現仍製備出品質良好的鈦金屬改質層，並且改質層浸泡於水中八天仍具有一定的穩定性。未來希望透過細胞測試更進一步確認不同比例的共聚物何者具有較良好的生物相容性以利未來實際使用。

Because titanium-based materials have relatively good biocompatibility, well mechanical, corrosion resistance and non-magnetic properties, it has been widely used in the field of biomaterial medical implants to replace tradition material, stainless steel and cobalt alloy etc. However, owing to the problems with poor hemo-compatibility, anti-biofouling ability and long healing time, they have limited the application of titanium-based materials on hard tissue replacement, osteosynthesis devices, heart valves and vascular stents.
The object of this investigation was to develop a novel surface modification strategy for titanium-based material to improve biocompatibility and osseointegration. We synthesized two monomers that one with carboxylic acid group which is biocompatibility and well-adhesion for cell, called 6-acryloyloxyhexanoic acid (AHA), the other with phosphonates group which was an anchor group for metal surface, called 11-Acryloyloxy undecyl phosphonic acid (AcrUPA), and their co-polymer (AxHy). These copolymers should be able to bind on the titanium surface to form a well biocompatibility film. We hope this ideal could be a new way to improve the titanium-based medical implants.
The properties of the copolymers were characterized with nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and thermo-gravimetric analysis (TGA). We applied the spin coating to form a uniform film on the titanium surface after the copolymers were successful synthesized.
Then the modified titanium substrates were heated for forming the covalent bond between phosphonic acid and titanium substrate. Finally, the modified titanium substrate surface were tested by static water contact angle measurement, scanning electron microscope (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to learn the surface hydrophilic/hydrophobic, films stability, surface roughness and surface atomic ratio percent.
We found that the copolymer molecular weight was not high enough. We speculated that it was resulted from the hydrophilic/ hydrophobic difference of the monomers and the AHA molecular tendency to self-aggregation. Thought the molecular was not high enough, we could control the condition of spin coating to produce well quality and stable films that was tested by several surface analyses.
In the future, we will test cell response on titanium substrate surface with a which different monomer ratio copolymer modified. And then, we will understand which one promoted the biocompatibility most.

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