Liposomes and nanotechnology in drug development: focus on oncotargets

Abstract

Nanotechnology is the development of an engineered device at the atomic, molecular, and macromolecular level in the nanometer range. Advances in nanotechnology have proven beneficial in therapeutic fields such as drug-delivery and gene/protein delivery. Antigen delivery systems are important for inducing and modifying immune responses. In cellular immunity, cytotoxic T lymphocytes (CTLs) are important in the host defense against tumors. Key to the development of CTL-inducible vaccines is the ability to deliver antigens to antigen-presenting cells efficiently and to induce the subsequent activation of T cell-mediated immunity without adjuvants, as they can induce excessive inflammation leading to systemic febrile disease. Since expression and cloning methods for tumor-associated antigens have been reported, cancer vaccines that induce effective cell immunity may be promising therapeutic candidates, but Th2 cells are undesirable for use in cancer immunotherapy. Peptide vaccines have immunological and economic advantages as cancer vaccines because CTL epitope peptides from tumorassociated antigens have high antigen-specificity. However, cancer vaccines have had limited effectiveness in clinical responses due to the ability of cancer cells to "escape" from cancer immunity and a low efficiency of antigen-specific CTL induction due to immunogenic-free synthetic peptides. In contrast, carbohydrate-decorated particles such as carbohydrate-coated liposomes with encapsulated antigens might be more suitable as antigen delivery vehicles to antigen-presenting cells. Oligomannose-coated liposomes (OML) can eliminate established tumors in mouse cancer models. In addition, OMLs with an encased antigen can induce antigenspecific CTLs from peripheral blood mononuclear cells obtained from patients. Feasibility studies of OML-based vaccines have revealed their potential for clinical use as vaccines for diseases where CTLs act as effector cells. Furthermore, use of the hepatitis B core particle, in which tumor-antigen epitopes are set, has consistently been shown to induce strong CTL responses without the use of an adjuvant. Thus, nanoparticles may provide a new prophylactic strategy for infectious disease and therapeutic approaches for cancer via the induction of T-cell immunity.

Liposomes as vaccine delivery systems: a review of the recent advances

“…HPV), chromosomal translocation products (e.g. bcr/abl), overexpressed proteins likeHER2/ neu, telomerase, MUC1 and others [Kozako et al 2012]. In Table 3 some recent examples of experimental liposome-based cancer vaccines are listed.…”

Comparative Study of PEGylated and Conventional Liposomes as Carriers for Shikonin

“…Furthermore, they can result in controlled therapeutic levels of the drug for a prolonged time. A proper drug delivery agent could modify the solubility and improve the stability of candidate drugs, and lead to an improved ADME profile (Absorption, bioDistribution, Metabolism, and Excretion) [16,17].…”

Multidynamic Liposomes in Nanomedicine: Technology, Biology, Applications, and Disease Targeting

“…Moreover, newly developed different liposomal combinations/formulations and liposomal vaccines have shown promising results in clinical studies and in commercial applications. In all, liposomal formulations are still important and potential tool for its clinical application of nanomedicines [45,50,61,63,65,.…”

“…Liposomes in the nanosize range have been recognized as a versatile drug delivery system of both hydrophilic and lipophilic molecules. [65,[113][114][115][116][117][118][119] (continued) [125] (continued) MDR, multi-drug resistant;…”