Precision medicine in breast cancer: Targeting molecular subtypes with gold nanoparticle-loaded liposomes

PURPOSE

Breast cancer is a complex disease with several molecular subtypes that respond differently to therapy. This paper describes liposomes loaded with gold nanoparticles as a targeted drug delivery method in the rapidly developing precision breast cancer treatment area. The aim was to investigate the cytotoxicity level and cellular uptake using several breast cancer cell lines and a normal breast cell line.

MATERIALS AND METHODS

We synthesized gold nanoparticles incorporated in liposomes. Nanostructures were incubated with breast cancer cell lines of different subtypes. The analysis included MTT assay, flow cytometry and immunofluorescence.

RESULTS

Cell viability varied among different cancer cells. Moreover, the time- and concentration-dependent manner of viability change was observed. The internalization of liposomes with gold nanoparticles and nanoparticles alone determined different results depending on molecular breast cancer subtypes. The luminal B and triple-negative breast cancer cells demonstrated the highest resistance and sensitivity, respectively. The intensity of cells' interaction with the proposed nanostructures was observed in both cell lines. In this study, we compare the molecular subtypes of breast cancer and discuss how this novel method might improve the therapy success.

CONCLUSIONS

Our research sheds light on the possibility of new individualized treatments for breast cancer patients, opening the path for better results and a more detailed cancer therapy strategy.

Advances in Liposome-Encapsulated Phthalocyanines for Photodynamic Therapy

This updated review aims to describe the current status in the development of liposome-based systems for the targeted delivery of phthalocyanines for photodynamic therapy (PDT). Although a number of other drug delivery systems (DDS) can be found in the literature and have been studied for phthalocyanines or similar photosensitizers (PSs), liposomes are by far the closest to clinical practice. PDT itself finds application not only in the selective destruction of tumour tissues or the treatment of microbial infections, but above all in aesthetic medicine. From the point of view of administration, some PSs can advantageously be delivered through the skin, but for phthalocyanines, systemic administration is more suitable. However, systemic administration places higher demands on advanced DDS, active tissue targeting and reduction of side effects. This review focuses on the already described liposomal DDS for phthalocyanines, but also describes examples of DDS used for structurally related PSs, which can be assumed to be applicable to phthalocyanines as well.

Insight into theranostic nanovesicles prepared by thin lipid hydration and microfluidic method

Liposomes are phospholipid-based self-assembled nanoparticles. Various components can be solubilized in the lipid bilayer, encapsulated in the aqueous core or attached to the surface, making liposomes attractive platforms for multimodality functionalization. Here we describe theranostic liposomes delivering a magnetic resonance contrast agent (lipid derivative of gadopentetic acid) and a hydrophobic photosensitizer (zinc phthalocyanine, ZnPc) for photodynamic therapy of cancer. For the first time, this theranostic system was prepared by the microfluidic method. Analogous formulations were produced by thin lipid film hydration (TLH) with down-sizing performed by extrusion for comparison purposes. We demonstrated double the loading capacity of ZnPc into liposomes made by microfluidics compared to TLH/extrusion. Microfluidics resulted in the theranostic nanoliposomes characterized by sizes =2.5x smaller than vesicles prepared by TLH/extrusion. Increased relaxivity was observed for liposomes manufactured by microfluidics compared to TLH, despite a slightly lower Gd chelate recovery. We attributed the improved relaxation to the increased surface area/volume ratio of vesicles and decreased phosphatidylcholine/ZnPc molar ratio, which affected water molecules' diffusion through the liposomal membrane. Finally, we showed photodynamic efficacy of ZnPc loaded into theranostic liposomes in head and neck cancer model, resulting in IC₅₀ of 0.22 - 0.61 μM, depending on the formulation and cell line used. We demonstrate microfluidics' feasibility to be used for theranostic liposome manufacturing and co-entrapment of therapeutic and imaging components in a single-step process with a high yield.