REPOSITORY > RESULTS

Abstract

The development of efficient, biocompatible drug delivery systems is a major challenge in modern medicine, particularly for nucleic acid-based therapies. This doctoral dissertation explores bioinspired and biomimetic nanocarriers designed for the delivery of small-interfering RNA (siRNA), offering novel approaches to address pharmacokinetic limitations, immune recognition, and delivery efficiency. The work focuses on the synthesis, characterization, and therapeutic evaluation of nanocarriers inspired by natural systems such as erythrocytes and natural crosslinkers. The thesis integrates principles of nanotechnology, gene therapy, pharmacology, and materials science to present a multidisciplinary strategy for enhancing siRNA delivery via nanomedicine.
The first part of the thesis provides a comprehensive review of nanomedicine, outlining its historical development, key innovations in drug delivery systems, approved nanodrugs (including gene therapy) and the emerging field of theranostics—where therapeutic and diagnostic functions are combined in a single nanosystem. Nanodrugs offer several advantages over conventional therapies, including prolonged circulation time, reduced toxicity, improved biodistribution, and the ability to cross biological barriers. However, challenges such as immune system recognition and activation, clearance by the reticuloendothelial system (RES), and endosomal trapping remain significant obstacles.
To overcome these, we researched erythrocyte membrane vesicles (EMVs) as natural, stealth carriers that retain immune-evasive markers such as CD47, enabling prolonged systemic circulation and passive tumor targeting via enhanced permeation and retention effect. Genipin-crosslinked polyamine nanoparticles (GxS5) are also developed for their ability to complex siRNA and their inherent fluorescence properties, which facilitate real-time tracking. The work further explores the combination of these two approaches through a hybrid system in which GxS5 nanoparticles are coated with erythrocyte membranes, merging the advantages of both carriers. The EMV formulation also show promise in terms of stability, controlled release, and imaging capabilities using indocyanine green (ICG) dyes for photothermal therapy. Several hypotheses are addressed, including the impact of zwitterionic surface modifications, membrane fusion mechanisms, and the Enhanced Permeability and Retention (EPR) effect in tumor tissue.
Through a series of in experiments, we demonstrated the effectiveness of these nanocarriers in delivering siRNA to melanoma-derived tumors in vivo and in vitro, and lymphoblastoid cell lines, achieving significant gene knockdown with minimal cytotoxicity.
This research contributes to the ongoing evolution of non-viral gene therapy methods and underscores the potential of bioinspired materials in next-generation nanomedicine. By tailoring carriers to evade immune responses, promote targeted delivery, and integrate diagnostic functions, this thesis presents a comprehensive platform for the treatment of genetic and oncological diseases. The findings support the feasibility of multifunctional nanocarriers and provide a foundation for future clinical translation. The dissertation concludes with a critical assessment of the limitations and prospects of RNAi-based treatments, highlighting the importance of rational design, biocompatibility, and adaptability in therapeutic development.