6.4　Characterization of Polymer Nano-Drug Carriers

The physical，chemical，and biological properties of the polymer nano-drug carriers affect their ability in drug delivery，disease diagnosis and treatment.Therefore，how to effectively evaluate the performance of polymer nano-drug carriers is essential in the design，screening，and optimization of carriers.Characterizations of polymer nano-drug carriers can be performed in vitro and in vivo.The in vitro characterizations include the particle size and its distribution，zeta（ζ）potential，morphology，drug loading content，encapsulation efficiency，release profile，and responsiveness，etc.The in vivo characterizations include the distribution，targeting，and biocompatibility.Compared with the in vivo characterizations，the in vitro characterizations are more convenient and rapid，and have fewer variabilities.Researchers have established the relationship between the in vitro and in vivo characterizations for some polymer nano-drug carriers.These experiences and principles help us to find the desired polymer nano-drug carrier materials quickly by in vitro experiments，thereby avoiding the use of animals.In this section，we will introduce the instruments and techniques for the evaluation of in vitro/in vivo characterizations.(https://www.daowen.com)