pH- and temperature-sensitive, injectable, biodegradable block copolymer hydrogels as carriers for paclitaxel

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Paclitaxel (PTX) is a potent anti-cancer drug with limited solubility.
• Developing effective drug delivery systems for PTX is crucial for cancer therapy.
• Block copolymers offer potential as advanced drug carriers due to their tunable properties.

Purpose of the Study:

• To synthesize and characterize a novel pH/T-sensitive block copolymer (OSM-PCLA-PEG-PCLA-OSM).
• To investigate the loading and release kinetics of paclitaxel (PTX) within the block copolymer solution.
• To evaluate the in vivo anti-tumor efficacy of the PTX-loaded block copolymer hydrogel.

Main Methods:

• Synthesis of OSM-PCLA-PEG-PCLA-OSM block copolymer.
• Loading of paclitaxel (PTX) into the block copolymer solution at various concentrations.
• Phase diagram analysis of PTX-loaded block copolymer solutions.
• In vitro drug release studies.
• Subcutaneous injection into tumor-bearing mice followed by TUNEL assay for apoptosis analysis.

Main Results:

• The phase diagram of PTX-loaded block copolymer solution shifted to lower temperatures due to PTX's salting-out effect.
• Sustained release of PTX was observed, irrespective of the initial drug loading concentration.
• The PTX-loaded block copolymer hydrogel exhibited significant anti-tumor effects for two weeks in vivo.
• Strong induction of apoptosis was detected in tumor tissues treated with the hydrogel.

Conclusions:

• OSM-PCLA-PEG-PCLA-OSM block copolymer serves as an effective injectable carrier for paclitaxel (PTX).
• The developed hydrogel demonstrates promising sustained drug delivery and anti-tumor activity.
• This system holds potential for advanced cancer treatment strategies.