ABSTRACT
PURPOSE: An oligonucleotide termed 'T-oligo' having sequence homology with telomere overhang has shown cytotoxicity in multiple cancers. We have demonstrated that T-oligo can induce apoptosis in androgen independent prostate cancer cell line DU-145. In this report, we evaluate the use of star-shaped tetraspermine (SSTS) for delivery of T-oligo. METHODS: SSTS was synthesized from spermine and its intrinsic cytotoxicity towards DU-145 cells was compared with spermine and branched polyethyleneimine (bPEI). Atomistic molecular dynamic (MD) simulations were conducted to understand binding and complexation of spermine and SSTS with T-oligo. Complexation was also determined using gel electrophoresis and SYBR gold assay. Complexes were characterized for size, cellular uptake and antiproliferative effect. RESULTS: SSTS exhibited significantly lower toxicity than spermine and bPEI. Its affinity towards T-oligo was significantly higher than spermine as determined by experimental studies and confirmed by MD simulations and it formed stable complexes (TONPs) with T-oligo. TONPs facilitated cellular uptake and nuclear accumulation of T-oligo and their cytotoxic potential was observed at concentration several folds lower than that required for T-oligo alone. CONCLUSION: SSTS significantly enhanced therapeutic benefits associated with the use of T-oligo and can be developed as a delivery vehicle for its in-vivo therapeutic applications.
Subject(s)
Antineoplastic Agents/pharmacology , Drug Carriers/chemistry , Edetic Acid/analogs & derivatives , Nanoparticles/chemistry , Oligonucleotides/pharmacology , Prostatic Neoplasms , Spermine/analogs & derivatives , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacokinetics , Cell Culture Techniques , Cell Line, Tumor , Cell Survival/drug effects , Drug Carriers/chemical synthesis , Edetic Acid/chemical synthesis , Edetic Acid/chemistry , Flow Cytometry , Humans , Male , Molecular Conformation , Molecular Dynamics Simulation , Oligonucleotides/administration & dosage , Oligonucleotides/pharmacokinetics , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Spermine/chemical synthesis , Spermine/chemistryABSTRACT
A variety of delivery vehicles use spermine as a polycationic component to form complexes with nucleic acids. Thus, we investigated the influence of molecular architecture, amine density, and molecular weight of oligospermines on its binding to nucleic acids. We report the synthesis of mono, bis, and tetraspermines with linear, cyclic, dendritic, and quatrefoil architecture. The effect of molecular weight was more pronounced in linear oligospermines than their cyclic counterparts. Oligospermines with similar amine density but different molecular architectures exhibited different binding profiles. Among all oligospermines evaluated, dendritic tetraspermine exhibited the highest binding affinity. Atomistic molecular dynamics simulations also indicated higher affinity for dendritic tetraspermine to siRNA than its linear counterpart suggesting the importance of spermine geometry in binding to nucleic acids. Importantly, dendritic tetraspermine was less toxic than linear tetraspermine, suggesting its potential in nucleic acid delivery.
ABSTRACT
Folic acid, transferrin and integrin alpha v beta 3 (αvß3) receptors are overexpressed in various cancer cell lines. Ligands having high affinity for these receptors are often conjugated to nanocarriers to facilitate the tumor localization of therapeutic agents. In this review the use of these ligands for targeted delivery using liposomes, dendrimers and (N-(2-hydroxypropyl) methacrylamide) (HPMA) copolymers is discussed. Emphasis is placed on discussing drug delivery systems that have been optimized for in-vitro binding as well as in-vivo pharmacokinetics. Our aim is to understand the various factors influencing the targeting ability of nanocarriers.
