Monoporous Microsphere as a Dynamically Movable Drug Carrier for Osteoporotic Bone Remodeling

Abstract

To repair systematically osteoporotic bone defects, it is important to make an effort to both diminish osteoporosis and enhance bone regeneration. Herein, a specifically monoporous microsphere (MPM) carrier encapsulating dosage-sensitive and short half-time parathyroid hormone (PTH) is constructed to tackle the issue. Compared with conventional microsphere carriers involving compact, porous, and mesoporous microspheres, the MPM is desirable to achieve precisely in situ delivery and to minimize topical accumulation. The findings show that the PTH loaded inside MPMs can be gradually released from the single hole of MPMs to improve the initial drug concentration. Also, the MPMs can self-shift with the daily movement of experimental animals to effectively reduce the topical aggregation of released drugs in vitro. In vivo evaluation further confirms that the implant of MPMs-PTH plays a dual role in stimulating the regenerative repair of the cranial defect and relieving osteoporosis in the whole body. Consequently, the current work develops a dynamically movable drug delivery system to achieve precisely in situ delivery, minimize topical accumulation, and systematically repair osteoporotic bone defects.

Keywords: drug delivery; monoporous microspheres; osteoporotic bone defects; parathyroid hormone.