Synthesis and antitumour activity of new dendritic polyamines-(imide-DNA-intercalator) conjugates: potent Lck inhibitors

Advances in combination therapies based on nanoparticles for efficacious cancer treatment: an analytical report

The main objective of nanomedicine research is the development of nanoparticles as drug delivery systems or drugs per se to tackle diseases as cancer, which are a leading cause of death with developed nations. Targeted treatments against solid tumors generally lead to dramatic regressions, but, unfortunately, the responses are often short-lived due to resistant cancer cells. In addition, one of the major challenges of combination drug therapy (called "cocktail") is the crucial optimization of different drug parameters. This issue can be solved using combination nanotherapy. Nanoparticles developed in oncology based on combination nanotherapy are either (a) those designed to combat multidrug resistance or (b) those used to circumvent resistance to clinical cancer drugs. This review provides an overview of the different nanoparticles currently used in clinical treatments in oncology. We analyze in detail the development of combinatorial nanoparticles including dendrimers for dual drug delivery via two strategic approaches: (a) use of chemotherapeutics and chemosensitizers to combat multidrug resistance and (b) use of multiple cytotoxic drugs. Finally, in this review, we discuss the challenges, clinical outlook, and perspectives of the nanoparticle-based combination therapy in cancer.

Study on the synthesis, biological activity and spectroscopy of naphthalimide-diamine conjugates

Eleven novel naphthalimide-diamine conjugates were synthesized and their structures were confirmed by elemental analysis, 1H-NMR, 13C-NMR and MS. Their in vitro antitumor activities were assessed using MTT assays on two cancerous cell lines K562, HCT116, and one normal hepatoma cell line QSG 7701. Compound 7f exhibited potent antitumor activity on HCT116 cells and favorable cell selectivity toward QSG 7701 compared with the positive control, amonafide. Moreover, 7f could block HeG2 cells in the G2/M phase and induce HeG2 cells apoptosis. The interaction of compound 7f with herring sperm DNA was studied by UV/vis absorption and fluorescence spectroscopy under physiological conditions (pH = 7.4). The observed spectral quenching of compound 7f by DNA and the displacement of EB from DNA-EB complex by compound 7f indicated that compound 7f could intercalate into DNA base pairs, which was also corroborated by the effect of KI on compound-DNA interaction. Further caloric fluorescent tests revealed that the quenching mechanism was a static type. Meanwhile, the binding constants, thermodynamic parameters and the effect of NaCl on compound-DNA interaction showed that the type of interaction force was mainly hydrogen bonds and the binding process was driven by hydrogen and van der Waals bonding.

Efficient palladium-catalyzed double carbonylation of o-dibromobenzenes: synthesis of thalidomide

A convenient and mild procedure for double carbonylation of o-dibromobenzene with various 2-amino pyridines and naturally occurring amines has been developed. N-Substituted phthalimides were produced in good to excellent yields. Furthermore, thalidomide was produced in excellent yield under these conditions.

Solubility of aceclofenac in polyamidoamine dendrimer solutions

In the present study we investigated the effect of polyamidoamine (PAMAM) dendrimers on the aqueous solubility of aceclofenac. The aqueous solubility of aceclofenac was measured in the presence of dendrimers in distilled water. The effect of variables, such as pH condition, concentration, temperature and generation (molecule size) of dendrimer, has been investigated. Results showed that the solubility of aceclofenac in the dendrimer solutions was proportional to dendrimer concentration. The order in which the dendrimers increased the solubility at a constant pH condition was G3 > G0. The influence of dendrimer solution pH on the solubility enhancement of aceclofenac suggests that it involves an electrostatic interaction between the carboxyl group of the aceclofenac molecule and the amine groups of the dendrimer molecule. The solubility of aceclofenac was inversely proportional to the temperature of dendrimer solution.Different generation (G0 and G3) PAMAM dendrimers have the potential to significantly enhance the solubility of poor water-soluble drugs.

Novel and versatile methodology for synthesis of cyclic imides and evaluation of their cytotoxic, DNA binding, apoptotic inducing activities and molecular modeling study

Versatile method has been developed for synthesis of N-substituted imides. Thus, acid anhydrides, imides and dicarboxylic acids were successfully subjected to dehydrative cyclization with substituted amines using DPPOx and Et(3)N to afford N-substituted imides under mild conditions. The DNA binding and apoptosis induction were investigated with regard to their potential utility as cytotoxic agents. Molecular modeling methods are used to study the cytotoxic activity of the active compounds by means of molecular and quantum mechanics.

Solubility of nicotinic acid in polyamidoamine dendrimer solutions

In the present study we investigated the effect of ethylenediamine (EDA) core polyamidoamine (PAMAM) dendrimers on the aqueous solubility of nicotinic acid. The aqueous solubility of nicotinic acid was measured in the presence of dendrimers at room temperature in distilled water. The effect of variables, such as pH condition, concentration, surface functional group and generation (molecule size) of dendrimer, has been investigated. Results showed that the solubility of nicotinic acid in the dendrimer solutions was proportional to dendrimer concentration, both amine and ester-terminated dendrimers caused the higher increase in nicotinic acid solubility at higher pH conditions. The order in which the dendrimers increased the solubility at a constant pH condition was G4>G3>G2>G1. In addition, at each pH, the solubility of nicotinic acid was greater in the presence of amine-terminated dendrimers compared to the amine ester-terminated dendrimers possessing the same number of surface functional groups. Under suitable conditions PAMAM dendrimers can be highly effective used to enhance the solubility of nicotinic acid.

Dendrimers as potential drug carriers. Part I. Solubilization of non-steroidal anti-inflammatory drugs in the presence of polyamidoamine dendrimers

The aqueous solubility of non-steroidal anti-inflammatory drugs (NSAIDs) Ketoprofen, Ibuprofen, Diflunisal and Naproxen were measured in the presence of the ethylenediamine (EDA) core polyamidoamine (PAMAM) dendrimers at 37 degrees C. The effect of concentration and generation of the PAMAM dendrimers has been investigated. Results showed that the solubility of NSAIDs in the PAMAM dendrimer solutions was approximately proportional to dendrimer concentration; the solubility of NSAIDs in higher generation PAMAM solutions was in fact higher that those in lower ones; the order of increased solubility of NSAIDs in PAMAM dendrimers at a constant dendrimer concentration and generation was Naproxen>Ketoprofen>Ibuprofen>Diflunisal. Under suitable conditions PAMAM dendrimers can be highly effective used to enhance the solubility of NSAIDs.