中空介孔硅球原位接枝聚苯胺及其pH响应性药物控制释放行为

In situ Graft of Polyaniline on Hollow Mesoporous Silica Nanospheres for pH-operated Drug Release

通过原位化学氧化聚合的方法,在中空介孔二氧化硅纳米粒子表面成功接枝上了聚苯胺(HMSsPANI).借助透射电镜(TEM)、红外光谱(FTIR)、紫外可见吸收光谱(UV-Vis)、氮气脱附吸附等温测试(BET)、热失重(TGA)、小角粉末衍射(XRD)和zeta电位测试等手段表征了其结构性质.通过循环伏安曲线研究,发现HMSs-PANI分散体系在不同pH条件下具有电化学活性的转变性质,证实了HMSs-PANI在酸性条件下能够进行有效的掺杂从而具有电化学活性.最后用HMSs-PANI来负载抗癌药物盐酸阿霉素(DOX),其展现了良好的酸性pH可控释放行为,在pH=7.4时,22 h后仅有15%的药物累计释放量.在pH=5的条件下,22 h后累计释放量达到44%,而在pH=4条件且同样时间之下,释放量为60%.总之,合成的HMSs-PANI酸响应药物控制释放体系在药物传输领域具有潜在应用.

Polyanline-grafted hollow mesoporous silica nanoparticles （HMSs-PANI） were successfully prepared by in situ chemical oxidative polymerization. The functionalized processes of nanoparticles were characterized by transmission electron microscopy （ TEM ） , Fourier transform （FTIR） , ultraviolet-visible spectroscopy （UV-Vis）, thermogravimetric analyses （TGA） and zeta potentials test. The changes of the mesoporous properties of nanoparticles during the processes of modification were tested by N2 adsorption- desorption isotherms and small-angle powder X-ray diffraction （XRD）. Then, cyclic voltammetry （CV） experiments of dispersed systems were carried out to study the electroactive properties of HMSs-PANI under different pH and showed good electroactive properties at acidic solution （pH = 4） because of the effective acid doping. While at neutral solution,it lost electroactive properties. Moreover, HMSs-PANI as nanocontainers was used to load anti-cancer drug doxorubicin hydrochloride （DOX）. Anticipative controlled release behavior of HMSs-PANI was observed by different pH stimulation in vitro. The release profiles of DOX from nanocontainers in pH =7.4 solutions were only 15% at 22 h. When the pH value is decreased to 5 ,the DOX molecules rapid released and the percentage of release reached 44% at 22 h. When the pH value further decreased to 4,the faster rate was observed and the percentage of release reached 60% at the same time. In short, the pH- responsiveness of HMSs-PANI may have practical applications in the field of drug delivery system.