Liposomal doxorubicin as targeted delivery platform: Current trends in surface functionalization

The significant challenges faced by modern-day medicine include designing a target-specific drug delivery system with a controlled release mechanism, having the potential to avoid opsonization and reduce bio-toxicity. Nanoparticles are materials with nanoscale dimensions and maybe natural and synthetic in origin. Engineered nano-sized materials are playing an indispensable role in the field of nanomedicine and nanobiotechnology. Besides, engineered nano-sized particles impart therapeutic applications with enhanced specificity because of their unique bespoke properties. Moreover, such application-customized nanoparticles offer an enormous possibility for their compatibility with different biological molecules like proteins, genetic materials, cell membranes, and organelles at the nano-bio frame. Besides, surface functionalization with targeting moieties such as small molecule ligands, monoclonal antibodies, aptamers, cell-penetrating peptides, and proteins facilitate nanoparticle-based specific tissue targeting. This review summarizes some of the advances in nanoparticle-based therapeutics and theranostics. A better understanding of idealistic preparation methods, physicochemical attributes, surface functionalization, biocompatibility can empower the potential translation of nanomaterials from the ‘bench-to-bedside’. In modern-day medicine, engineered nanoparticles have a wide range of demands ranging from bio-imaging, theranostics, tissue engineering, sensors, drug and nucleic acid delivery, and other pharmaceuticals applications. 2D and 3D mammalian cell-based assays are widely used to model diseases, screening of drugs, drug discovery, and toxicity analyses. Recent advances in cell culture technology and associated progress in nanotechnology have enabled researchers to study a wide variety of physiologically relevant questions. This chapter explores the properties of nanoparticles, different targeted delivery methods, biological analysis, and theranostics. Moreover, this chapter also emphasizes biosafety and bioethics associated with mammalian cell culture and discusses the significance of intellectual property rights from an industrial and academic perspective.

Download Full-text

Achieving dendritic cell subset-specific targeting in vivo by site-directed conjugation of targeting antibodies to nanocarriers

10.1101/2021.07.14.452311 ◽

2021 ◽

Author(s):

Johanna Simon ◽

Michael Fichter ◽

Gabor Kuhn ◽

Maxmimilian Brueckner ◽

Cinja Kappel ◽

...

Keyword(s):

Surface Functionalization ◽

Targeted Delivery ◽

Immune Cell ◽

Specific Interaction ◽

Cell Subset ◽

Target Cells ◽

Dendritic Cell Subset ◽

Specific Targeting ◽

Body Distribution

The major challenge of nanocarrier-based anti-cancer vaccination approaches is the targeted delivery of antigens and immunostimulatory agents to cells of interest, such as specific subtypes of dendritic cells (DCs), in order to induce robust antigen-specific anti-tumor responses. An undirected cell and body distribution of nanocarriers can lead to unwanted delivery to other immune cell types like macrophages reducing the vaccine efficacy. An often-used approach to overcome this issue is the surface functionalization of nanocarriers with targeting moieties, such as antibodies, mediating cell type-specific interaction. Numerous studies could successfully prove the targeting efficiency of antibody-conjugated carrier systems in vitro, however, most of them failed when targeting DCs in vivo that is partly due to cells of the reticuloendothelial system unspecifically clearing nanocarriers from the blood stream via Fc receptor ligation. Therefore, this study shows a surface functionalization strategy to site-specifically attach antibodies in an orientated direction onto the nanocarrier surface. Different DC-targeting antibodies, such as anti-CD11c, anti-CLEC9A, anti-DEC205 and anti-XCR1, were conjugated to the nanocarrier surface at their Fc domains. Anti-mouse CD11c antibody-conjugated nanocarriers specifically accumulated in the targeted organ (spleen) over time. Additionally, antibodies against CD11c and CLEC9A proved to specifically direct nanocarriers to the targeted DC subtype, conventional DCs type 1. In conclusion, site-directed antibody conjugation to nanocarriers is essential in order to avoid unspecific uptake by non-target cells while achieving antibody-specific targeting of DC subsets. This novel conjugation technique paves the way for the development of antibody-functionalized nanocarriers for DC-based vaccination approaches in the field of cancer immunotherapy.

Download Full-text

Versatile Encapsulation and Synthesis of Potent Therapeutic Liposomes by Thermal Equilibration

10.1101/2021.10.22.465473 ◽

2021 ◽

Author(s):

Steven A Roberts ◽

Chaebin Lee ◽

Shrishti Singh ◽

Nitin Agarwal

Keyword(s):

Small Molecules ◽

Targeted Delivery ◽

Liposomal Doxorubicin ◽

Metastatic Breast ◽

Cancer Cell Line ◽

Dynamic Simulations ◽

Liposome Membrane ◽

Thermal Equilibration ◽

Wide Scale ◽

Synthesis Approach

The wide-scale use of liposomal delivery systems is hampered by difficulties in obtaining potent liposomal suspensions. Passive and active loading strategies have been proposed to formulate drug encapsulated liposomes, but are limited by low efficiencies (passive) or high drug specificities (active). Here, we present an efficient and universal loading strategy for synthesizing therapeutic liposomes. Integrating a thermal equilibration technique with our unique liposome synthesis approach, co-loaded targeting liposomes can be engineered in an efficient and scalable manner with potencies 200-fold higher than typical passive encapsulation techniques. We demonstrate this capability through simultaneous co-loading of hydrophilic and hydrophobic small molecules and through targeted delivery of liposomal Doxorubicin to a metastatic breast cancer cell line MDA-MB-231. Molecular dynamic simulations are used to explain interactions between Doxorubicin and liposome membrane during thermal equilibration. By addressing the existing challenges, we have developed an unparalleled approach that will facilitate the formulation of novel theranostic and pharmaceutical strategies.

Download Full-text

Intracellular Targeting of Poly Lactic-Co-Glycolic Acid Nanoparticles by Surface Functionalization with Peptides

Journal of Biomedical Nanotechnology ◽

10.1166/jbn.2021.3108 ◽

2021 ◽

Vol 17 (7) ◽

pp. 1320-1329

Author(s):

Thaís Dolzany de Oliveira ◽

Luiz R. Travassos ◽

Denise Costa Arruda ◽

Dayane Batista Tada

Keyword(s):

Drug Delivery ◽

Surface Functionalization ◽

Glycolic Acid ◽

Release Kinetics ◽

Cell Penetrating Peptides ◽

Cell Uptake ◽

Intracellular Targeting ◽

Cell Internalization ◽

Material Choice ◽

Delivery Platform

Nanoparticles (NPs) are a promising strategy for delivering drugs to specific sites because of their tunable size and surface chemistry variety. Among the availablematerials, NPs prepared with biopolymers are of particular interest because of their biocompatibility and controlled release of encapsulated drugs. Poly lactic-co-glycolic acid (PLGA) is one of the most widely used biopolymers in biomedical applications. In addition to material choice modulation of the interaction between NPs and biological systems is essential for the safety and effective use of NPs. Therefore, this work focused on evaluating different surface functionalization strategies to promote cancer cell uptake and intracellular targeting of PLGA NPs. Herein, cell-penetrating peptides (CPPs) were shown to successfully drive PLGA NPs to the mitochondria and nuclei. Furthermore, the functionalization of PLGA NPs with peptide AC-1001 H3 (GQYGNLWFAY) was proven to be useful for targeting actin filaments. The PLGA NPs cell internalization mechanism by B16F10-Nex2 cells was identified as caveolae-mediated endocytosis, which could be inhibited by the presence of methyl-β-cyclodextrin. Notably, when peptide C (CVNHPAFAC) was used to functionalize PLGA NPs, none of the tested inhibitors could avoid cell internalization of PLGA NPs. Therefore, we suggest this peptide as a promising surface modification agent for enhancing drug delivery to cancer cells. Finally, PLGA NPs showed slow release kinetics and low cytotoxic profile, which, combined with the surface functionalization strategies addressed in this study, highlight the potential of PLGA NPs as a drug delivery platform for improving cancer therapy.

Download Full-text