Floating poly(lactic-co-glycolic acid)-based controlled-release drug delivery system for intravesical instillation

Abstract

Objectives To investigate the floating, structural, and controlled-release characteristics of a floating poly(lactic-co-glycolic acid) (PLGA)-based controlled-release drug delivery system, and determine the feasibility of this drug delivery system for intravesical instillation. Methods PLGA was dissolved in dimethylacetamide, then mixed with IR780 and doxorubicin (DOX) to prepare a drug delivery system capable of solidification and flotation on water at room temperature. Preparations of PLGA, PLGA+IR780, PLGA+DOX, and PLGA+IR780+DOX were formulated. Their floating characteristics in vivo and in vitro were investigated, along with their structural and controlled-release characteristics. Preparations of saline, DOX, and PLGA+IR780+DOX were also formulated; the content of DOX in bladder tissue delivered by each preparation was determined by fluorescence microscopy. Results PLGA exhibited stable flotation in vivo and in vitro. A honeycomb structure was observed by scanning electron microscopy. When irradiated with a near-infrared laser, IR780 generated heat that vitrified PLGA, allowing controlled release of DOX from the drug delivery system. The PLGA+IR780+DOX preparation achieved the highest content of DOX in bladder tissue. Conclusions Our floating PLGA-based controlled-release drug delivery system exhibited a honeycomb stabilized structure and achieved controlled release when irradiated by a near-infrared laser, making it an ideal drug delivery system for intravesical instillation.