Liposomes: From a Clinically Established Drug Delivery System to a Nanoparticle Platform for Theranostic Nanomedicine

Abstract

For decades, clinicians have used liposomes, self-assembled lipid vesicles, as nanoscale systems to deliver encapsulated anthracycline molecules for cancer treatment. The more recent proposition to combine liposomes with nanoparticles remains at the preclinical development stages; however, such hybrid constructs present great opportunities to engineer theranostic nanoscale delivery systems, which can combine simultaneous therapeutic and imaging functions. Many novel nanoparticles of varying chemical compositions are being developed in nanotechnology laboratories, but further chemical modification is often required to make these structures compatible with the biological milieu in vitro and in vivo. Such nanoparticles have shown promise as diagnostic and therapeutic tools and generally offer a large surface area that allows covalent and non-covalent surface functionalization with hydrophilic polymers, therapeutic moieties, and targeting ligands. In most cases, such surface manipulation diminishes the theranostic properties of nanoparticles and makes them less stable. From our perspective, liposomes offer structural features that can make nanoparticles biocompatible and present a clinically proven, versatile platform for further enhancement of the pharmacological and diagnostic efficacy of nanoparticles. In this Account, we describe two examples of liposome-nanoparticle hybrids developed as theranostics: liposome-quantum dot hybrids loaded with a cytotoxic drug (doxorubicin) and artificially enveloped adenoviruses. We incorporated quantum dots into lipid bilayers, which rendered them dispersible in physiological conditions. This overall vesicular structure allowed them to be loaded with doxorubicin molecules. These structures exhibited cytotoxic activity and labeled cells both in vitro and in vivo. In an alternative design, lipid bilayers assembled around non-enveloped viral nanoparticles and altered their infection tropism in vitro and in vivo with no chemical or genetic capsid modifications. Overall, we have attempted to illustrate how alternative strategies to incorporate nanoparticles into liposomal nanostructures can overcome some of the shortcomings of nanoparticles. Such hybrid structures could offer diagnostic and therapeutic combinations suitable for biomedical and even clinical applications.

Radionuclide-labeled nanostructures for In Vivo imaging of cancer

“…Liposomes are clinically well-established drug delivery vehicles with properties including biocompatibility, high drug-to-carrier ratios, and straightforward drug encapsulation capability [70][71][72][73]. The polar and non-polar domains of the molecules comprising the liposome structure allow the stable encapsulation of both hydrophilic and hydrophobic agents.…”

Liposome-Encapsulated Biomolecules: Application in Enzymatic Biosensors and Immunosensors

“…39 [47][48][49][50] Devido à afinidade, biocompatibilidade com os tecidos e células do organismo e capacidade de incorporar e estabilizar biomoléculas e fármacos tanto hidrossolúveis como lipossolúveis, os lipossomos são vantajosos para aplicação na área médica e farmacêutica, como por exemplo, carreadores de fármacos para células alvo. 51,52 Os lipossomos imobilizados em superfícies sólidas também estão sendo explorado para liberação de fármacos 53 e para estabilização de biomoléculas em biossensores, 1,5 neste último, a estabilização ajuda a manter a atividade biológica e, consequentemente, melhora a seletividade e sensibilidade dos dispositivos. A seguir serão descritos algumas aplicações de lipossomos em biossensores enzimáticos e imunossensores.…”

Nanodrug Delivery Systems: A Promising Technology for Detection, Diagnosis, and Treatment of Cancer

“…For example, in a recent report, nanoparticles, such as fluorescent quantum dots (Qdots) or superparamagnetic iron oxide nanoparticles, are incorporated in liposomes with doxorubicin for simultaneous delivery of imaging and therapeutic agents, respectively (15,16). Researchers have also attempted to coat lipid bilayer over Qdot-labeled non-enveloped adenoviral vectors for safe and efficient delivery of tumor suppressor genes and imaging agents (15,16). This typical strategy of lipid modification enhanced the tumor accumulation efficiency of the viral vectors and improved the biocompatibility of the Qdots.…”