光热敏感型羧甲基壳聚糖纳米微球的制备及光热性能

Preparation and photothermal properties of photothermal sensitive carboxymethyl chitosan nanospheres

羧甲基壳聚糖因其具有良好的水溶性和生物相容性,被广泛应用于生物医学领域。以天然可降解高分子羧甲基壳聚糖为载体,在引发剂过硫酸钾的作用下,通过自由基组合法将N-异丙基丙烯酰胺接枝到羧甲基壳聚糖上,然后在香草醛的交联作用下,采用乳化交联法制备一种负载光敏剂吲哚菁绿(ICG)的新型光热敏感型羧甲基壳聚糖微球,通过傅里叶红外(FT-IR)、核磁(1H-NMR)及扫描电镜(SEM)对共聚物结构及微球形貌进行表征,考察了油水比、转速、香草醛、乳化时间对该纳米微球包载阿霉素载药量的影响,并研究了其光热性能。结果表明,FT-IR和1H-NMR分析证明,N-异丙基丙烯酰胺成功接枝到羧甲基壳聚糖上;SEM分析可知,纳米微球外观呈球状,分布均匀,平均粒径为143 nm。油水比为20∶1,转速为600 r/min,香草醛量为1 mL,乳化时间3 h的微球载药量最高为19.32%。同时,通过改变外界环境条件,纳米微球能缓慢靶向释放药物,具有良好的光热敏感性,该纳米微球在药物控释及药物载体等领域有广泛的应用前景。

Carboxymethyl chitosan is widely used in biomedical field due to its good water solubility and biocompatibility.In this paper,N-isopropylacrylamide was grafted onto carboxymethyl chitosan by free radical combination method under the action of initiator potassium persulfate with natural degradable polymer carboxymethyl chitosan as carrier.Then,a new photo-thermal sensitive carboxymethyl chitosan microsphere loaded with photosensitizer indocyanine green(ICG)was prepared by emulsion crosslinking method under the crosslinking effect of vanillin.Fourier transform infrared(FT-IR),nuclear magnetic resonance(1H-NMR)and scanning electron microscope(SEM)were used to characterize the structure of the copolymer and the morphology of the microspheres.The effects of oil-water ratio,rotation speed,vanillin and emulsification time on the drug loading rate of adriamycin in the nanospheres were investigated,and their photothermal properties were also studied.The experimental results shows that Fourier transform infrared(FTIR)and nuclear magnetic(1H-NMR)analysis proved that N-isopropylacrylamide was successfully grafted onto carboxymethyl chitosan.Scanning electron microscopy showed that the appearance of the nanospheres was spherical,with uniform distribution and an average particle size of 143 nm.The drug loading rate of microspheres with oil-water ratio of 20∶1,rotating speed of 600 r/min,vanillin content of 1 mL and emulsifying time of 3 h was the highest 19.32%.At the same time,the nano microspheres could slowly release drugs in a targeted manner and had good photothermal sensitivity.The nano microspheres had wide application prospects in the fields of drug controlled release,drug carriers and the like.