Eteshola Edward, Pandian Ramasamy P, Lee Stephen C, Kuppusamy Periannan
Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210, USA.
Biomed Microdevices. 2009 Apr;11(2):379-87. doi: 10.1007/s10544-008-9244-x.
Crystalline lithium phthalocyanine (LiPc) can be used to sense oxygen. To enhance biocompatibility/stability of LiPc, we encapsulated LiPc in Teflon AF (TAF), cellulose acetate (CA), and polyvinyl acetate (PVAc) (TAF, previously used to encapsulate LiPc, was a comparator). We identified water-miscible solvents that don't dissolve LiPc crystals, but are solvents for the polymers, and encapsulated crystals by solvent evaporation. Oxygen sensitivity of films was characterized in vitro and in vivo. Encapsulation did not change LiPc oximetry properties in vitro at anoxic conditions or varying partial pressures of oxygen (pO2). EPR linewidth of encapsulated particles was linear with pO2, responding to pO2 changes quickly and reproducibly for dynamic measurements. Encapsulated LiPc was unaffected by biological oxidoreductants, stable in vivo for four weeks. Oximetry, stability and biocompatibility properties of LiPc films were comparable, but both CA and PVAc films are cheaper, and easier to fabricate and handle than TAF films, making them superior.
结晶态锂酞菁（LiPc）可用于检测氧气。为提高LiPc的生物相容性/稳定性，我们将LiPc封装于聚四氟乙烯AF（TAF）、醋酸纤维素（CA）和聚醋酸乙烯酯（PVAc）中（TAF此前用于封装LiPc，作为对照）。我们确定了不溶解LiPc晶体但能溶解聚合物的与水混溶的溶剂，并通过溶剂蒸发来封装晶体。对薄膜的氧敏感性进行了体外和体内表征。在缺氧条件或不同氧分压（pO2）下，封装并未改变LiPc在体外的血氧测定特性。封装颗粒的电子顺磁共振线宽与pO2呈线性关系，对于动态测量，能快速且可重复地响应pO2变化。封装的LiPc不受生物氧化还原物质影响，在体内可稳定四周。LiPc薄膜的血氧测定、稳定性和生物相容性特性相当，但CA和PVAc薄膜都比TAF薄膜便宜，且更易于制造和处理，使其更具优势。
