Effect of platelet exosomes loaded with doxorubicin as a targeted therapy on triple-negative breast cancer cells

Exosomes have come to the fore in drug delivery systems due to their biological-based and immune-suppressing properties. In this study, we investigated the effect of doxorubicin loading of exosomes isolated from human platelets on breast cancer.Exosomes released from ADP (1 µM)-activated platelets were isolated by the ultracentrifugation method, and their size and charge were measured with a TEM and zeta sizer. Then doxorubicin (Dox) loading into exosomes (PLT-Exo-Dox) was done by electroporation and incubated with MDA-MB-231 cells. In exosome characterization, CD62 positivity was higher in platelet pellets, while CD9 positivity was higher in released exosomes. The size of PLT-Exo and PLT-Exo-Dox was 82.02 ± 5.21 nm and 116 ± 3.73 nm, with a polydispersity index of 0.26 ± 0.04 and 0.39 ± 0.06, and the Zeta potential was - 16.45 mV and 24.07 mV, respectively. The encapsulation efficiency of the preparation was 86.02 ± 6.16%, with a drug loading capacity of 4.75 ± 0.16 µg/µg of the exosome. In MDA-MB-231 cells, PLT-Exo increased cell viability, while PLT-Exo-Dox decreased in 24 h. The Annexin-V binding level and Bax gene expression were increased in PLT-Exo-Dox and Bcl-2 gene expression was decreased. This study will shed light on the development of release systems that can be effective with chemotherapeutic agents by using exosomes released by cells in the development of personalized treatments.

Exploring the link between chronobiology and drug delivery: effects on cancer therapy

Circadian clock is an impressive timing system responsible for the control of several metabolic, physiological and behavioural processes. Nowadays, the connection between the circadian clock and cancer occurrence and development is consensual. Therefore, the inclusion of circadian timing into cancer therapy may potentially offer a more effective and less toxic approach. This way, chronotherapy has been shown to improve cancer treatment efficacy. Despite this relevant finding, its clinical application is poorly exploited. The conception of novel anticancer drug delivery systems and the combination of chronobiology with nanotechnology may provide a powerful tool to optimize cancer therapy, instigating the incorporation of the circadian timing into clinical practice towards a more personalized drug delivery. This review focuses on the recent advances in the field of cancer chronobiology, on the link between cancer and the disruption of circadian rhythms and on the promising targeted drug nanodelivery approaches aiming the clinical application of cancer chronotherapy.

Methods for the In Vitro Characterization of Nanomedicines-Biological Component Interaction

The design of colloidal nanosystems intended for biomedical applications, specifically in the field of personalized medicine, has increased notably in the last years. Consequently, a variety of characterization techniques devoted to studying nanomedicine interactions with proteins and cells have been developed, since a deep characterization of nanosystems is required before starting preclinical and clinical studies. In this context, this review aims to summarize the main techniques used to assess the interaction of nanomedicines with biological systems, highlighting their advantages and disadvantages. Testing designed nanomaterials with these techniques is required in order to have more information about their behavior on a physiological environment. Moreover, techniques used to study the interaction of nanomedicines with proteins, such as albumin and fibrinogen, are summarized. These interactions are not desired, since they usually are the first signal to the body for the activation of the immune system, which leads to the clearance of the exogenous components. On the other hand, techniques for studying the cell toxicity of nanosystems are also summarized, since this information is required before starting preclinical steps. The translation of knowledge from novel designed nanosystems at a research laboratory scale to real human therapies is usually a limiting or even a final point due to the lack of systematic studies regarding these two aspects: nanoparticle interaction with biological components and nanoparticle cytotoxicity. In conclusion, this review will be a useful support for those scientists aiming to develop nanosystems for nanomedicine purposes.

Human pathological basis of blood vessels and stromal tissue for nanotechnology

The recent development of nanotechnology has already produced clinically applicable "nanodrugs," which are largely dependent on a novel concept for the drug delivery system. Thus the elucidation of local pharmacokinetics of nanodrugs is indispensable for the further development of nanomedicine; however, the detailed pathophysiology associated with nano-sized materials especially in pathologic lesions has not been well-described. In this review article, the microscopic appearance of vascular pericytes in addition to endothelial cells is discussed in the normal state and also in several pathological conditions which could be the major targets for nanomedicine. Moreover, the role of stromal tissue including myofibroblasts is also focused on, as well as inflammatory cells. Finally, the significance of disease-specific tissue structure in the establishment of personalized nanomedicine is discussed.