Injectable Hydrogel-Microsphere Construct with Sequential Degradation for Locally Synergistic Chemotherapy.

Area of Science:

• Biomedical Engineering
• Materials Science
• Oncology

Background:

• In situ chemotherapy using biodegradable polymers is gaining traction.
• Osteosarcoma treatment requires effective drug delivery and reduced systemic toxicity.

Purpose of the Study:

• To develop a sequential drug delivery system for synergistic osteosarcoma treatment.
• To evaluate the efficacy and biocompatibility of a hydrogel-microsphere construct.

Main Methods:

• Fabrication of a thermosensitive polypeptide hydrogel loaded with combretastatin A-4 (CA4) and docetaxel (DTX) microspheres (Gel-MP construct).
• Assessment of sequential drug release, biodegradability, and biocompatibility.
• In vivo evaluation of the Gel-MP construct in a mouse osteosarcoma model using histopathology and immunohistochemistry.

Main Results:

• The Gel-MP construct demonstrated sequential biodegradability and good biocompatibility.
• CA4 release preceded DTX release, disrupting tumor vasculature and enhancing DTX penetration.
• In vivo studies showed significant suppression of osteosarcoma growth with the Gel-MP construct.
• The system upregulated anti-proliferation effects and reduced drug toxicity.

Conclusions:

• The injectable Gel-MP construct enables localized, sequential chemotherapy for synergistic osteosarcoma treatment.
• This advanced drug delivery system shows promise for clinical applications in in situ chemotherapy.