Microspheres and Microcapsules for Protein Delivery: Strategies of Drug Activity Retention
Lianyan Wang, Yuan Liu, Weifeng Zhang, Xiaoming Chen, Tingyuan Yang and Guanghui Ma
Affiliation: National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
With the recent progress in biotechnology and genetic engineering, a variety of proteins have formed a very important class of
therapeutic agents. However, most proteins have short half-lives in vivo requiring multiple treatments to provide efficacy. In order to
overcome this limitation, sustained release systems as hydrophilic microspheres and hydrophobic microcapsules have received extensive
attention in recent years. As therapeutic proteins delivery systems, it is necessary to maintain protein bioactivity during microspheres or
microcapsules formation as much as possible. This paper reviews different influencing factors that are closely involved in protein denaturation
during the preparation of hydrophilic polymer microspheres and hydrophobic polymer microcapsules. The various strategies usually
employed for overcoming these obstacles are described in detail. Both processing and formulation parameters can be modified for
improving protein stability. The maximum or full protein stability retention within the microspheres or microcapsules might be achieved
by individual or combined optimized strategies. In addition, the common techniques for proteins stability determination are also briefly
Keywords: Hydrophilic polymer microspheres, hydrophobic polymer microcapsules, protein delivery, activity retention, strategies.
Rights & PermissionsPrintExport