Comparative study on the functionalization of biomimetic magnetoliposomes targeting LGR5: Potential applications as...

Multifunctional nanoplatforms that combine targeted drug delivery, hyperthermia, and bioimaging are essential for precision oncology. This study describes the design and characterization of biomimetic magnetoliposomes (BML) functionalized with specific peptides (PA, PB, PC, PD) and the RSPO1 protein to target LGR5-overexpressing colorectal cancer (CRC) cells. BML were synthesized to encapsulate 5-fluorouracil (5-FU) and biomimetic magnetic nanoparticles (BMNPs). BML exhibited hydrodynamic diameters of 120-130 nm and a negative ζ-potential. TEM confirmed the incorporation of Fe₃O₄ cores within the liposomal structure. The 5-FU loading efficiency was 0.16 mg/mL (1.23%DL), with a marked pH-responsive release profile: minimal leakage at neutral pH (<12% at 120 min) and up to 62% under acidic conditions. Magnetothermal studies revealed that the functionalized nanoformulations exhibited improved magnetic properties. BML-RSPO1 achieved the highest SAR (22.71 W/g) and produced the greatest temperature amplification (4.03 °C increase) under clinically safe conditions. In vitro MHT experiments showed significant cytotoxicity, with BML-PC-MHT reducing tumor cell viability by 68.26%, associated with increased ROS and activation of necrotic and apoptotic pathways. BML-PC and BML-RSPO1 also displayed superior transverse relaxivity (up to 94.86 mM^-1 s^-1), supporting their MRI contrast potential. Uptake assays indicated a dual internalization mechanism involving non-specific pathways and a possible receptor-mediated pathway, particularly in LGR5-expressing cells. Our findings position functionalized BML as promising theranostic nanoplatforms, integrating pH-sensitive chemotherapy delivery, efficient magnetothermal performance under MHT treatment, and high-relaxivity MRI contrast capabilities. These biomimetic systems offer a versatile and multifunctional strategy for simultaneous tumor treatment and non-invasive monitoring, particularly in LGR5-positive tumors, supporting their potential for future development as precision nanomedicines.