EGFR-targeted hybrid lipid nanoparticles for chemo-photothermal therapy against colorectal cancer cells

Antibody-functionalized targeted nanocarriers have shown great-potential for minimizing the chemoresistance and systemic toxicity of cancer chemotherapies. The combination of chemotherapy and photothermal therapy has great potential in improving therapeutic effect. However, cetuximab-modified nanoparticles based lipids for chemo-phototherapy of EGFR overexpressing colorectal carcinoma (CRC) have seldom been investigated. Hence, this study aimed to fabricate cetuximab-conjugated and near infrared (NIR) light-responsive hybrid lipid-polymer nanoparticles (abbreviated as Cet-CINPs) for targeted delivery of irinotecan. Cet-CINPs were prepared with copolymer PLGA and various lipids DSPE-PEG, DSPE-PEG-Mal, lecithin as carriers. Cetuximab was conjugated on the surface of nanoparticles to achieve targeting anti-tumor efficacy. Cet-CINPs were characterized in terms of morphology (spherical), size (119 nm), charge (-27.2 mV), drug entrapment efficiency (43.27 %), and antibody conjugation efficiency (70.87 %). Cet-CINPs showed preferable photothermal response, pH/NIR-triggered drug release behavior, enhanced cellular uptake and ROS level compared with free ICG and CINPs. Meanwhile, in vitro cytotoxicity assay showed that Cet-CINPs with NIR irradiation had a higher cytotoxicity against Lovo cells than non-targeted or non-NIR activated nanoparticles. The IC₅₀ values of Cet-CINPs with NIR irradiation was 22.84 ± 1.11 μM for 24 h and 5.01 ± 1.06 μM for 48 h, respectively. These investigations demonstrate that Cet-CINPs with good tumor-targeting ability and enhanced antitumor activity, are a promising multifunctional nanoplatform for CRC therapy.

Hybrid core-shell particles for mRNA systemic delivery

mRNA based infectious disease vaccines have opened the venue for development of novel nucleic acids-based therapeutics. For all mRNA therapeutics dedicated delivery systems are required, where different functionalities and targeting abilities need to be optimized for the respective applications. One option for advanced formulations with tailored properties are lipid-polymer hybrid nanoparticles with complex nanostructure, which allow to combine features of several already well described nucleic acid delivery systems. Here, we explored hyaluronic acid (HA) as coating of liposome-mRNA complexes (LRCs) to investigate effects of the coating on surface charge, physicochemical characteristics and biological activity. HA was electrostatically attached to positively charged complexes, forming hybrid LRCs (HLRCs). At different N/P ratios, physico-chemical characterization of the two sets of particles showed similarity in size (around 200 nm) and mRNA binding abilities, while the presence of the HA shell conferred a negative surface charge to otherwise positive complexes. High transfection efficiency of LRCs and HLRCs in vitro has been obtained in THP-1 and human monocytes derived from PBMC, an interesting target cell population for cancer and immune related pathologies. In mice, quantitative biodistribution of radiolabeled LRC and HLRC particles, coupled with bioluminescence studies to detect the protein translation sites, hinted towards both particles' accumulation in the hepatic reticuloendothelial system (RES). mRNA translated proteins though was found mainly in the spleen, a major source for immune cells, with preference for expression in macrophages. The results showed that surface modifications of liposome-mRNA complexes can be used to fine-tune nanoparticle physico-chemical characteristics. This provides a tool for assembly of stable and optimized nanoparticles, which are prerequisite for future therapeutic interventions using mRNA-based nanomedicines.