pH-responsive Nanomedicine Delivery Platform Based on Silicon Nanoparticles for Imaging and Photodynamic Therapy of Tumor Cells.

INTRODUCTION

Fluorescent silicon nanoparticles (Si NPs) are attractive bioimaging probes, but their emission is mainly confined to the blue-green region, resulting in poor penetration into tissues and strong autofluorescence interference. Moreover, most systems based on Si NPs are designed for single-function imaging or sensing, which limits their use in the delivery and treatment of tumortargeted drugs.

METHODS

Long wavelength fluorescent Si NPs with high physicochemical stability have been synthesised and incorporated into mesoporous silica nanoparticles (MSNs) for drug delivery. Chlorine e6 (Ce6) has been encapsulated as a photosensitizer. The resulting nanocomposites were coated with polydopamine (PDA) and functionalised with folic acid (FA) to realize active tumor-targeting capability.

RESULTS

The synthesized Si NPs showed stable long-wavelength fluorescence suitable for biological imaging. The FA-Si NPs-MSNs-PDA@Ce6 nanocomposite benefited from the FA-mediated targeting, increased permeability and retention effects and demonstrated increased tumor accumulation and cellular uptake. This strategy achieved tumor-specific fluorescence imaging, permitted real-time tracking of tumor cells, and boosted intracellular Ce6 delivery, thereby significantly elevating the photodynamic therapy (PDT) efficiency Discussion: This study presents a multifunctional nanoplatform that combines long-wave fluorescence imaging and pH-sensitive photodynamic therapy, thereby overcoming the significant limitations of traditional silicon nanoparticle-based systems. Targeted delivery and controlled release of drugs improve the accuracy of therapy and the effectiveness of imaging, and offer a promising strategy for tumor theranostics.

CONCLUSION

A multifunctional drug delivery nanoplatform based on Si NPs integrating targeted fluorescence imaging and photodynamic therapy has been successfully developed. This system holds great promise for tumor-targeted drug delivery and integrated theranostic applications.