An enzyme-responsive and NIR-triggered lipid-polymer hybrid nanoplatform for synergistic photothermal/chemo cancer therapy

A combination of photothermal therapy (PTT) and chemotherapy is an emerging therapeutic strategy with promising clinical prospects in cancer treatment. Despite the huge progress achieved in the past years, a number of obstacles still hamper the therapeutic efficacy of this synergistic modality such as uneven heat distribution, lack of targetability of anti-cancer agents and dosage-related side effects. Thus, developing a nanoplatform for targeted drug delivery against cancer is of great necessity. Herein, a lipid-polymer hybrid nanosystem (LP/ID) based on polyethyleneimine (PEI)-lecithin-polyethylene glycol (PEG) was fabricated to co-load indocyanine green (ICG) and dichloroacetate (DCA) for combined photothermal/chemotherapy. DCA and ICG were linked to the PEI backbone to form a dense hydrophobic core through amide bonds and electrostatic interactions, which increased the payload of DCA and ICG as well as achieved enzyme-responsive drug release because of the overexpressed amidase in tumor cells. Lecithin and DSPE-PEG₂₀₀₀ self-assembled around the hydrophobic complexes to obtain prolonged blood circulation and attenuated systemic toxicity of the hybrid nanosystem. The prepared LP/ID exhibited favourable stability in a physiological environment, good tumor imaging properties, and satisfactory photothermal/chemotherapeutic performance. Moreover, LP/ID could also enhance the cellular uptake and tumor retention capacity in comparison with free drug administration. Notably, by co-loading two therapeutic agents with different anti-cancer mechanisms, an obvious inhibitory effect on tumor growth was observed with negligible damage to normal tissues and organs because of the synergistic photothermal/chemotherapy effect, indicating the great potential of LP/ID as a robust nanoplatform for cancer treatment.

Deposition of Antibody Modified Upconversion Nanoparticles on Glass by a Laser-Assisted Method to Improve the Performance of Cell Culture

A suitable surface is vital for maintaining or even promoting cells' function and communication. Recently, studies show that nanostructured coatings could have a potential in improving cell adhesion. However, it hardly minimizes the contamination by using traditional solution-coating technology. Matrix-assisted pulsed laser evaporation (MAPLE) technique is a contamination-free process and demonstrates an efficient process to deposit biopolymer without damaging their backbone on the surface of various substrates. Here, upconversion nanoparticles (NaGdF4: Yb3+, Er3+) with/without immunoglobulin G (IgG) modification were produced by a one-pot synthesis method. The average size of the upconversion nanoparticles (UCNPs) is 50 ± 8 nm. IgG bio-conjugated on the surface of UCNPs can be directly observed by transmission electron microscope (TEM). MAPLE system utilizing a Nd:YAG laser (λ = 532 nm, ν = 10 Hz) is applied to deposit UCNPs with/without IgG modification on the glass bottom of culture dish. In addition, the behaviors of human umbilical vein endothelial cells (HUVECs) cultured on the culture dishes coated with UCNPs with/without IgG have been studied as compared to the control sample, glass coated with gelatin. No toxic effect is imposed on cells. The results of this work indicate that the deposition of UCNPs with/without antibody by the MAPLE technique could enhance the adhesion and proliferation of cells.

Neto E, Mazali IO, Murugesu M, Sigoli FA. One pot synthesis and systematic study of the photophysical and magnetic properties and thermal sensing of α and β-phase NaLnF4 and β-phase core@shell nanoparticles

Hierarchical nanostructured nanoparticles showing high values of relative thermal sensitivity and magnetization at low temperatures.