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Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles
Published on: August 28, 2015
Poly(ethylene glycol)-sheddable reduction-sensitive polyurethane micelles for triggered intracellular drug delivery
Zhengjie Yang1,2, Qianping Guo1, Yan Cai1
1Department of Orthopedic Surgery, The First Affiliated Hospital of Soochow University, Orthopedic Institute, Soochow University, Suzhou, China.
Background:
The survival rate of osteosarcoma therapy still lags behind overall cancer therapies due to the intrinsic or acquired drug resistance. Developing novel drug delivery systems that may overcome drug resistance would greatly facilitate osteosarcoma therapy.
Methods:
Poly(ethylene glycol) (PEG)-sheddable reduction-sensitive polyurethane (SS-PU-SS-PEG) was synthesized using a disulfide-containing polycaprolactone diol as the hydrophobic block and a cystamine-functionalized PEG as the hydrophilic block. SS-PU-SS-PEG micelles were then prepared to load the anti-tumor drug Doxorubicin (DOX) in order to achieve triggered intracellular drug delivery to improve the efficacy of osteosarcoma therapy.
Results:
When DOX was used as a model drug, the drug-loaded SS-PU-SS-PEG micelles were about 82∼94 nm in diameter and exhibited good stability in phosphate buffer saline (PBS). The micelles could release about 80% DOX in a quantitative fashion within 5 hours under a reductive environment. The intracellular drug release of DOX-loaded SS-PU-SS-PEG micelles increased upon incubation with Saos-2 cells in vitro. The micelles had good biocompatibility. In vitro, DOX-loaded SS-PU-SS-PEG micelles showed significant antitumor activity toward Saos-2 cells, which was close to that of free DOX. In vivo, DOX-loaded SS-PU-SS-PEG micelles exhibited better antitumor activity than free DOX.
Conclusion:
Findings from this study suggest that the SS-PU-SS-PEG micelles could achieve well-controlled triggered drug release in a reduction environment and could therefore improve the antitumor efficacy of osteosarcoma therapies.
Translation Potential Of This Article:
In this study we developed PEG-sheddable reduction-sensitive polyurethane micelles (SS-PU-SS-PEG), which were able to achieve well-controlled triggered release of anti-tumor drug Doxorubicin (DOX) in an intracellular reduction environment. DOX-loaded SS-PU-SS-PEG micelles markedly improved the antitumor efficacy in a Saos-2 cells-bearing xenograft tumor model. Therefore, such micelles might be used as a novel drug delivery system for osteosarcoma treatment.
Insights
Novel polyurethane micelles loaded with Doxorubicin show promise for osteosarcoma treatment by overcoming drug resistance. These micelles enable triggered drug release within cancer cells, enhancing therapeutic efficacy in vivo.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Oncology
Background:
- Osteosarcoma treatment survival rates lag due to drug resistance.
- Novel drug delivery systems are needed to overcome resistance in osteosarcoma therapy.
Purpose of the Study:
- To develop and evaluate PEG-sheddable, reduction-sensitive polyurethane micelles (SS-PU-SS-PEG) for triggered intracellular delivery of Doxorubicin (DOX).
- To assess the efficacy of these micelles in improving osteosarcoma treatment.
Main Methods:
- Synthesized SS-PU-SS-PEG micelles using disulfide-containing polycaprolactone and cystamine-functionalized PEG.
- Loaded micelles with DOX and evaluated their stability, drug release kinetics in reductive environments, and in vitro/in vivo antitumor activity.
- Tested micelles using Saos-2 cells and a xenograft tumor model.
Main Results:
- DOX-loaded SS-PU-SS-PEG micelles (82-94 nm) showed good stability and released DOX in a reductive environment within 5 hours.
- Intracellular drug release and in vitro antitumor activity against Saos-2 cells were significant.
- In vivo studies demonstrated superior antitumor efficacy compared to free DOX.
Conclusions:
- SS-PU-SS-PEG micelles facilitate controlled, triggered drug release in reductive intracellular environments.
- These micelles hold potential as a novel drug delivery system to enhance osteosarcoma treatment efficacy.
