Deep Tumor Penetration of Drug-Loaded Nanoparticles by Click Reaction-Assisted Immune Cell Targeting Strategy

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cancer Therapy

Background:

• Nanoparticles enhance drug delivery to tumors via passive (EPR) or active targeting.
• Limited nanoparticle penetration in tumors hinders therapeutic efficacy due to heterogeneous distribution.

Purpose of the Study:

• To develop a click reaction-assisted immune cell targeting (CRAIT) strategy for deep tumor penetration of drug-loaded nanoparticles.
• To leverage immune cells as vectors for enhanced drug delivery into avascular tumor regions.

Main Methods:

• Modified CD11b antibodies with trans-cyclooctene enabled bioorthogonal click chemistry with tetrazine-functionalized mesoporous silica nanoparticles (MSNs-Tz).
• Sequential injection of modified antibodies and MSNs-Tz facilitated nanoparticle conjugation onto CD11b+ myeloid cells.
• The strategy was tested in an orthotopic 4T1 breast tumor model.

Main Results:

• The CRAIT strategy achieved deep penetration of drug-loaded nanoparticles into tumor interiors.
• Targeted conjugation of nanoparticles onto immune cells resulted in enhanced therapeutic efficacy.
• The method demonstrated successful drug delivery without ex vivo cell manipulation.

Conclusions:

• The CRAIT strategy offers a promising approach for overcoming nanoparticle penetration limitations in tumors.
• This method effectively utilizes immune cells as active carriers for targeted drug delivery.
• The CRAIT strategy is versatile and applicable to various cell types and nanovehicles for cancer therapy.