2026-11-092026-11-09https://scholars.csmu.edu.tw/handle/123456789/38072題目：A study on the synthesis of superparamagnetic iron oxide assisted with r-ray and its characterization on potential application in molecular imaging. When the particle size of maghemite ( r-Fe2O3 ) or magnetite ( Fe3O4 ) is below a critical value ( say 35 nm ), the magnetic properties of each nanoparticle become single-domain and is free to align with an applied magnetic field ( i.e. there is no hysteresis ) – hence called as superparamagnetic iron oxide ( SPIO ). The biomedical applications of SPIO include ( 1 ) as MRI contrast agents due to the facts that SPIO are not immediately removed from the circulation by the reticuloendothelial system, providing a longer blood half-life and a wider biodistribution; trade name: Lumirem ( silicon-coated, 300 nm ), Endorem ( dextran-coated, 150 nm ), Sinerem ( dextran-coated, 30 nm ), ( 2 ) controlled drug delivery, ( 3 ) bioprocessing; in vitro cell separation, ( 4 ) magnetic intracellular hyperthermia, and ( 5 ) as MR molecular imaging agents. The applications of SPIO are affected by its different coating , size uniformity, and crystallinity. Chitosan usually represents copolymers of 2-amino-2-deoxyl-D-glucopyranose and 2-acetamido-2-deoxyl-D-glucopyranose ( chitin ) where the degree of deacetylation is generally more than 60%. It has somewhat specific good properties such as histocompatibility, nontoxicity, biodegradability, and bioactivity. Meanwhile it is easy to chemically modify both NH2 group and OH group on the molecule to obtain chitosan derivatives such as carboxyl methyl chitosan ( CM-chitosan ). Radiation is a very convenient tool to modify carbohydrates such as chitosan and cellulose through degradation, grafting, and crossinking. Most of SPIO was coated with dextran. Instead we intend to use chitosan and its derivatives to coat SPIO. The purpose of this research is to synthesize SPIO-CM-chitosan,in which we will employ r-ray to obtain an appropriate molecular weight of chitosan , to effect intracrosslinking of chitosan molecule, and to effect phase transformation of FeOOH, and finally to evaluate its biochemical and magnetic properties to see its potential application in molecular imaging. Chitosan has a very wide applications but not many reports about chitosan-coated SPIO. We hope with the assistance of r-ray to synthesize SPIO-CM-chitosan to open a new application of chitosan in MR molecular imaging.題目：利用輻射線合成奈米氧化鐵與其在分子影像應用之特性研究 當四氧化三鐵（Fe3O4）或γ- Fe2O3 的氧化鐵的粒徑小於35nm 後，即達到 奈米級時，其磁性之表現即不同，即每個氧化鐵顆粒之磁性即成為一個 Single-domain，在有外加磁場時才是磁鐵（ferromagnets），而無外加磁場時卻是 順磁性（paramagnetism），不再保有磁性，此種小於35nm 的奈米氧化鐵具有超 磁鐵（superparamagnets）特性。一般稱為superparamagnetic iron oxide（SPIO）。 奈米氧化鐵之醫學應用，包括：（1）當作MRI 對比劑；利用原理是這種SPIO 經由循環不會立即被網狀內皮系（reticuloendothetial system）移除，因此有較長 之血液半生期和較寬廣之身體分佈，商品有Lumirem（氧化矽包覆，300nm）， Endorem（dextran 包覆，Fe3O4，150nm），sinerem（dextran 包覆，Fe3O4，30nm）， （Brigger，2002）。（2）controlled drug delivery。（3）bioprocesssing；in vitro cell separateion。（4）magnetic intracellular hyperthermia。（5）當作MRI 分子影像造影 劑。 奈米γ-Fe2O3 之醫學應用受制於其different coating，size uniformity 和 crystallinity 之影響。 幾丁聚醣與生物體細胞有良好組織互溶性（histocompatibility），不會造成排 斥現象，幾乎無毒性，又可被生物分解（biodegradable），具有生物活性（biological function），另外其分子上之amino 和hydroxy group 易於化學修飾，製成衍生物， 更擴大它的使用範圍，如carboxyl methyl chitosan。 輻射線在碳水聚合物（carbohydrate）之利用，包括幾丁聚醣、sodium alginate， carrageenan，cellulose，pectin 等，經由放射線，可以使碳水聚合物裂解 （degradation），接枝（grafting）及交聯（crosslinking）。 奈米氧化鐵大多用 dextran 來包覆，本研究想用幾丁聚醣來包覆，並藉輻射線 之協助，選擇適當之幾丁聚醣分子量，及使包覆奈米氧化鐵之幾丁聚醣產生交聯反 應，增進包覆程度，而使奈米氧化鐵更加穩定，不會聚積成塊。在鹼性溶夜中之二 價鐵與三價鐵之反應中間產物為FeOOH，亦可用輻射線使之轉變為γ-Fe2O3。因此 本研究之目的是利用輻射線來： （1） 裂解幾丁聚醣，得到適當分子量（400kDa）。 （2） 使FeOOH 之結晶相轉變為γ-Fe2O3。 （3） 使包覆奈米氧化鐵之幾丁聚醣交聯。 （4） 評析SPIO – CM – chitosan 是否合適進一步進行特定生物接枝，作為 MRI 分子影像之造影劑。 幾丁聚醣之應用異常廣泛，但用在包覆奈米氧化鐵之文獻尚未多見，而充分 利用輻射線，是本研究之特色，對學術研究及幾丁聚醣之新應用開發有其貢獻。奈米氧化鐵放射線幾丁聚醣Project