Chitosan microparticles

Chitosan microparticles have been actively developed with an emphasis on preparative methods, particle characteristics, release control and in vivo applications. Many types have been produced, including simple microparticles, chemically cross-linked microparticles, ionically cross-linked microparticles, polyelectrolyte complex microparticles, and conjugated microparticles. Furthermore, chitosan derivatives can be used for the preparation of microparticles. In this review, preparative methods are discussed, along with the in vitro characteristics and in vivo studies of the microparticles or nanoparticles they produce. As chitosan microparticles are generally biocompatible, they are expected to have practical applications. In addition, mild interaction with cells, the mucosal membrane or tissue, which improves absorption or efficacy, is a property of chitosan micro- or nanoparticles not generally observed in other microparticles. Chitosan micro- and nanoparticles will need to be examined further to achieve controlled release, site-specific delivery, enhancement of absorption, etc.