Development of pH-Sensitive Cationic PEGylated Solid Lipid Nanoparticles for Selective Cancer-Targeted Therapy

Area of Science:

• Nanotechnology
• Materials Science
• Pharmacology

Background:

• Solid lipid nanoparticles (SLNs) show promise for anti-cancer drug delivery.
• Limitations include poor tumor permeability and non-specific uptake by the reticuloendothelial system.
• There is a need for improved nanoparticle-based drug delivery systems for enhanced cancer therapy.

Purpose of the Study:

• To develop novel pH-sensitive cationic polyoxyethylene (PEGylated) SLNs (PEG-SLNs+) for enhanced camptothecin (CPT) delivery.
• To evaluate the physicochemical properties, drug release, cellular uptake, and anti-tumor efficacy of CPT-loaded PEG-SLNs+ (CPT-PEG-SLNs+).
• To assess the long-term tumor accumulation and therapeutic potential of CPT-PEG-SLNs+ in vivo.

Main Methods:

• Synthesis and characterization of PEGylated cationic SLNs (PEG-SLNs+).
• Loading of camptothecin (CPT) into PEG-SLNs+ and determination of entrapment efficiency.
• In vitro drug release studies at different pH values (5.5 and 7.4).
• Cellular uptake studies in CL1-5 and HCC36 cancer cell lines.
• In vivo studies in tumor-bearing animal models to evaluate long-term tumor accumulation and therapeutic efficacy.

Main Results:

• CPT-PEG-SLNs+ were successfully prepared as spherical nanoparticles (∼52.3 nm) with positive charge (∼34.3 mV) and high CPT entrapment (∼99.4%).
• CPT-PEG-SLNs+ exhibited pH-sensitive drug release, with significantly higher release at pH 5.5 compared to pH 7.4.
• CPT-PEG-SLNs+ demonstrated efficient cellular uptake and potent inhibition of CL1-5 and HCC36 cell proliferation.
• In vivo, PEG-SLNs+ showed long-term accumulation ( >120 hours) in various tumor types.
• CPT-PEG-SLNs+ significantly enhanced the anti-tumor therapeutic efficiency of CPT, suppressing tumor growth in HCC36 and CL1-5 models.

Conclusions:

• The developed pH-sensitive PEGylated cationic SLNs (PEG-SLNs+) represent a promising platform for targeted and efficient cancer drug delivery.
• These nanoparticles overcome limitations of traditional SLNs by improving tumor permeability and prolonging tumor site accumulation.
• The findings suggest that PEG-SLNs+ can significantly enhance the therapeutic efficacy of anti-cancer drugs like CPT, offering a potential strategy for improved cancer therapy.