Development of new functionalized composite powders using plasma chemistry and its applications to drug engineering

用电子自旋共振（ESR）方法研究了等离子体诱导低密度聚乙烯（LDPE）自由基的形成，并与高密度聚乙烯（HDPE）的ESR谱进行了比较。等离子体辐照LDPE的ESR谱与HDPE的ESR谱有很大的不同，系统的计算机模拟结果表明，LDPE的这些组分自由基与HDPE的基本相同，但等离子体辐照LDPE的一个最特殊的特征是，是热稳定悬挂键位点（DBS）是主要组分自由基而不是中间-为了对等离子体诱导的聚碳水化合物表面自由基的解释有一个基本的认识，对等离子体辐照的二碳水化合物，如纤维二糖和麦芽糖进行了ESR研究，并与直链淀粉和纤维素进行了比较。模拟光谱表明，纤维二糖和麦芽糖的光谱分别由五种和四种光谱组成 ...更多信息 的光谱分量。作为等离子体辐照聚合物在开发药物新材料方面的应用，本文利用等离子体辐照聚合物在药物存在下的机械化学反应，制备了新型的基质型药物传递系统（DDS）。用机械力化学反应研究了等离子体辐照聚乙烯的自由基复合反应。结果表明，等离子体辐照后的聚乙烯容易发生机械力化学反应，DBS的消失速度比中链烷基快。基于这些实验结果，考察了在药物存在下通过等离子体辐照的PE的机械化学反应制备的粉末样品的药物释放。药物从粉末状样品中缓慢释放出来。结果表明，等离子体辐照聚乙烯可通过机械化学自由基复合反应制备基质型DDS，该方法适用于多种聚合物和药物，为全干法制备基质型DDS奠定了基础。少

Plasma-induced low-density polyethylene (LDPE) radicals were studied in detail by electron spin resonance (ESR) by its comparison with ESR spectra of high-density polyethylene (HDPE). The observed ESR spectra of plasma-irradiated LDPE are largely different in pattern from those of HDPE.The systematic computer simulation disclosed that all these component radicals of LDPE were essentially identical to those of HDPE.One of the most special features unique to plasma-irradiated LDPE, however, is the fact that thermally stable dangling bond sites (DBS) is a major component radical instead of a mid-chain alkyl radical in HDPE.To gain a fundamental insight on elucidation of plasma-induced surface radicals of polycarbohydrates, the ESR study on plasma-irradiated dicarbohydrates, such as cellobiose and maltose, was performed on its comparison with those on amylose and cellulose. The simulated spectra disclosed that the observed spectra of cellobiose and maltose consisted of five and four kinds … More of spectral components, respectively. The special feature of the radical formation in dicarbohydrates is the fact that the formation of surface DBS is negligible.As the application in the development of new pharmaceutically useful materials using plasma-irradiated polymer, the new matrix-type drug delivery system (DDS) was prepared by the mechanochemical reaction of plasma-irradiated polymer in the presence of drug. The radical recombination reaction of plasma-irradiated PE by mechanochemical reaction was examined. It was shown that the radical recombination reaction of plasma-irradiated PE easily underwent by mechanochemical reaction and that the DBS disappeared faster than the mid-chain alkyl radical. Based on these experimental results, the drug release from the powdered sample prepared by mechanochemical reaction of plasma- irradiated PE in the presence of drug was examined. The drug was slowly released from the powdered sample. It is cleared that the matrix-type DDS can be prepared by the mechanochemical radical recombination reaction using plasma-irradiated PE.This method can be applicable to a wide variety of polymer and drug, and is useful for the development of the matrix-type DDS by the totally dry process. Less