pH-Responsive Nanoparticle-Coated Calcium Phosphate Granules for Bone Cancer Therapy.

Area of Science:

• Biomaterials Science
• Oncology
• Nanotechnology

Background:

• Osteosarcoma (OS) is a prevalent bone cancer with poor survival rates and high recurrence.
• Current treatments face challenges with residual tumor cells and inadequate bone regeneration.
• Existing bifunctional bone grafts struggle with uncontrolled drug release and inefficient delivery.

Purpose of the Study:

• To develop a pH-sensitive nano-microparticle system for targeted osteosarcoma treatment and enhanced bone regeneration.
• To create a bifunctional bone scaffold that releases therapeutics on-demand within the tumor microenvironment.
• To improve intracellular delivery and control drug release for bone cancer therapy.

Main Methods:

• Fabrication of β-tricalcium phosphate (β-TCP) granules decorated with selenium (Se)-doped mesoporous silica nanoparticles (SeMIA@TCP).
• Functionalization of nanoparticles with imine bonds for pH-responsive release and alendronate for scaffold binding.
• In vitro evaluation of pH-dependent cytotoxicity against OS cells and toxicity toward human mesenchymal stem cells (hMSCs).
• Assessment of nanoparticle-induced osteogenic potential in hMSCs.

Main Results:

• SeMIA@TCP demonstrated pH-dependent cytotoxicity towards OS cells, with minimal toxicity to hMSCs at physiological pH.
• The system showed selective nanoparticle release in acidic tumor microenvironments.
• Released nanoparticles significantly enhanced alkaline phosphatase (ALP) expression and mineralization in hMSCs.
• Stable nanoparticle immobilization under physiological conditions was achieved.

Conclusions:

• Tumor microenvironment-responsive Se-doped MSN-assembled TCP granules represent a promising design for bifunctional scaffolds.
• This platform enables on-demand nanotherapeutic release, targeting osteosarcoma effectively.
• The developed scaffold holds potential for improving bone cancer treatment by combining anticancer activity with osteogenesis.