Dendrimers are new macromolecules synthesized in recent years, which are of great interests in many fields where they have potential important applications because of their hyperbranched, well defined and monodisperse structures. In this paper, the unique structures, general synthesis routes and basic physical and chemical properties of dendrimers are introduced in brief, and the progress in the research of dendrimers in drug (gene) delivery, contrast agents, cancer therapy were reviewed, as well as the perspective in research and applications.
Contrast Media ; chemistry ; Dendrimers ; chemistry ; pharmacology ; Drug Carriers ; chemistry ; Drug Delivery Systems ; Gene Transfer Techniques ; Humans ; Polyamines

OBJECTIVETo demonstrate the effectiveness of a retrovirus-based plasmid vector coupled with nanometer material-polyamidoamine (PAMAM) dendrimer in stable gene expression of FVIII in vitro and to study the cytotoxicity of PAMAM.

METHODSThe retrovirus-based plasmid vector pLNC-FVIII BD was generated by cloning a B-domain-deleted (760aa - 1639aa) FVIII cDNA (FVIIIBD cDNA) into retroviral vector pLNCX. The complex that contained PAMAM and pLNC-FVIII BD transfer FVIII BD cDNA into NIH3T3 cell line. In day 2, 5, 10, 15, 30 after transferring, the antigen and procoagulant activity of human FVIII in the cell culture medium were measured by ELISA assay and one-stage method, respectively. RT-PCR was performed for the detection of FVIII BD mRNA. Inhibitory percentage of cell vitality was used for cytotoxicity of PAMAM.

RESULTSHuman FVIII was expressed for 30 days by transfected cells. The mean procoagulant activity of secreted FVIII in these 30 days was 0.929 U/ml, and the FVIII antigen was 0.188 micro g/ml by 10(6) cells in 24 hours, respectively. The level of FVIII didn't significantly decreased during these days. Inhibitory percent of cell vitality was only 5.32%.

CONCLUSIONPAMAM could effectively transfer pLNC-FVIII BD into NIH3T3 cells and FVIII could be stably and effectively expressed by the transfected cells. Cytotoxicity of PAMAM was low.

Animals ; Dendrimers ; Factor VIII ; genetics ; Genetic Vectors ; genetics ; Mice ; NIH 3T3 Cells ; Plasmids ; Polyamines ; pharmacology ; Retroviridae ; genetics

A series of quinoline-polyamine conjugates (8a-8n) were designed, synthesized and evaluated as inhibitors of cholinesterases (ChEs). Some of these compounds had potent ChEs inhibitory activity with IC50 values at micromolar range. Compound 8n exhibited the strongest inhibition on acetylcholinesterase (AChE) with an IC50 value of 8.78 micromol x L(-1), and compound 8i showed the most potent inhibition on butyrylcholinesterase (BChE) with IC50 value of 1.60 micromol x L(-1) which was slightly better than rivastigmine. The structure-activity relationship revealed that the chain length of polyamine and linker played important roles for inhibitory activity. Molecular modeling studies showed that 8i targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of cholinesterases.
Acetylcholinesterase ; metabolism ; Butyrylcholinesterase ; metabolism ; Cholinesterase Inhibitors ; chemical synthesis ; chemistry ; pharmacology ; Drug Design ; Inhibitory Concentration 50 ; Polyamines ; chemical synthesis ; chemistry ; pharmacology ; Quinolines ; chemical synthesis ; chemistry ; pharmacology ; Structure-Activity Relationship

OBJECTIVETo study the expression of green fluorescent protein gene and immunogenicity of ES312 vaccine both mediated by Starburst polyamidoamine (PAMAM) dendrimers in vivo.

METHODSThe complex of green fluorescent protein or ES312 gene with Starburst PAMAM dendrimers were injected intramuscularly in Balb/c mice. The expression level and distribution of green fluorescent protein gene was detected by flow cytometer, Western blot and immunofluorescence assay. The immunogenicity of DNA vaccine was detected by enzyme-linked immunosorbent assay.

RESULTSThe expression of green fluorescent protein mediated by Starburst PAMAM dendrimers was found in heart, liver, spleen, lung, kidney, brain and injected muscle from 2 hours to 7 days after the vaccination. The highest expression level of the gene was detected in kidney, as well as in endothelial cells. The antibody response evoked by the DNA vaccine carried by the Starburst PAMAM dendrimers was significantly higher than that of the net DNA vaccination. Vaccination with Starburst PAMAM dendrimers elicited higher expression level of the gene in brain and kidney than with the net gene itself.

CONCLUSIONAs a novel non-viral DNA carrier with low self-antigenicity, Starburst PAMAM dendrimers have potential to mediate DNA transfer and expression in vivo.

Animals ; Biocompatible Materials ; pharmacology ; Dendrimers ; Drug Carriers ; pharmacology ; Female ; Green Fluorescent Proteins ; genetics ; pharmacokinetics ; Malaria Vaccines ; immunology ; Mice ; Mice, Inbred BALB C ; Polyamines ; pharmacology ; Vaccination ; Vaccines, DNA ; immunology

Six naphthalimide polyamine conjugates were synthesized and their structures were confirmed by elemental analysis, 1H NMR, 13C NMR and MS. Antitumor activities were evaluated in vitro using MTT assay on Leukemia cells (K562), human breast cancer cells (MB-231) and prostate cancer cells (Ln cap cell). The results showed that most of the six compounds were superior to the control (amonafide), 6d, 6e, and 6f exhibited nice selectivity in a screen of hepatoma cells (BEL-7402) and human normal hepatocytes (QSG-7701).
Antineoplastic Agents ; chemical synthesis ; pharmacology ; Cell Line, Tumor ; drug effects ; Humans ; Male ; Molecular Structure ; Naphthalimides ; chemical synthesis ; pharmacology ; Polyamines ; chemical synthesis ; pharmacology

UV radiation is known to cause photoaging of the skin and is considered one of the leading cause of developing skin carcinogenesis. Melatonin which has a highly lipophilic molecular structure facilitating penetration of cell membranes and serving as an extra- and intracellular free radical scavenger has been demonstrated to protect photodamage of skin affected by UV exposure. In this study, we have examined the role of melatonin in response to UVB induced photodamaging process, using human skin fibroblasts in vitro. Cell survival curves after UVB irradiation showed dose-dependent decrease. Only 60% of fibroblasts were survived at 140 mJ/cm2 UVB irradiation. By pre-cultivation of cells with melatonin (100 nM), a significant number of cells remained unaffected. After UVB irradiation with 70 mJ/cm2, the level of putrescine was 1.7+/-0.3 fold increased compared to melatonin pre-treated group. In Northern analyses, the transcriptional level of ornithine decarboxylase (ODC) gene expression was increased by UVB irradiation and prohibited by melatonin. These results indicated that melatonin was effectively able to neutralize membrane peroxidation when present in relevant concentration during UVB irradiation and diminishes the UVB-induced increase of polyamine synthesis and ODC gene expression. Collectively, ODC response to UVB induced changes are possibly involves a melatonin or antioxidant sensitive regulatory pathway in normal human skin fibroblast.
Antioxidants/*pharmacology ; Apoptosis/drug effects/radiation effects ; Fibroblasts/*drug effects/*radiation effects ; Human ; Melatonin/*pharmacology ; Ornithine Decarboxylase/biosynthesis/genetics ; Polyamines/*metabolism ; *Ultraviolet Rays

Polyamines (putrescine, spermidine, and spermine) are essential polycations that play important roles in various physiological and pathophysiological processes in mammalian cells. The study was to investigate their role in cardioprotection against ischemia/reperfusion (I/R) injury and the underlying mechanism. Isolated hearts from male Sprague-Dawley rats were Langendorff-perfused and cardiac I/R was achieved by 30 min of global ischemia followed by 120 min of reperfusion. Different concentrations of polyamines (0.1, 1, 10, and 15 μmol/L of putrescine, spermidine, and spermine), cyclosporin A (0.2 μmol/L), or atractyloside (20 μmol/L) were given 10 min before the onset of reperfusion. The hemodynamics were monitored; the lactate dehydrogenase (LDH) levels in the coronary effluent were measured spectrophotometrically; infarct size was determined by the 2,3,5-triphenyltetrazolium chloride staining method; and mitochondrial permeability transition pore (MPTP) opening was determined spectrophotometrically by the Ca-induced swelling of isolated cardiac mitochondria. The results showed that compared to I/R alone, 0.1 and 1 μmol/L polyamines treatment improved heart function, reduced LDH release, decreased infarct size, and these effects were inhibited by atractyloside (MPTP activator). In isolated mitochondria from normal rats, 0.1 and 1 μmol/L polyamines treatment inhibited MPTP opening. However, 10 and 15 μmol/L polyamines treatment had the opposite effects, and these effects were inhibited by cyclosporin A (MPTP inhibitor). Our findings showed that polyamines may have either protective or damaging effects on hearts suffering from I/R by inhibiting or activating MPTP opening.
Animals ; Cyclosporine ; pharmacology ; Male ; Mitochondria, Heart ; physiology ; Mitochondrial Membrane Transport Proteins ; physiology ; Myocardial Reperfusion Injury ; physiopathology ; Polyamines ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the apoptosis-inducing effects of NNAMB, a novel polyamine conjugate, in erythroleukemia K562 cells and its molecular mechanism.

METHODSCell viability was assessed by MTT assay and trypan blue dye exclusion method. The cell morphology was observed by fluorescence microscopy. The cell cycle distribution, apoptosis and mitochondrial membrane potential were measured by flow cytometry. The expression of caspase-3, -8, -9, cytochrome c in the K562 cells was detected by Western blot.

RESULTSNNAMB inhibited the proliferation of K562 cells. The cells treated with NNAMB showed a typical apoptotic morphology, Sub-G1 peak and loss of mitochondrial membrane potential. Western blot assay showed that NNAMB increased the expression of caspase-3, -9, cytochrome c but not caspase-8 in a dose-and time-dependent manner.

CONCLUSIONNNAMB induces apoptosis via mitochondrial pathway in K562 cells.

Anthracenes ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Caspase 9 ; metabolism ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cytochromes c ; metabolism ; Humans ; K562 Cells ; Membrane Potential, Mitochondrial ; drug effects ; Polyamines ; pharmacology ; Spermidine ; analogs & derivatives ; pharmacology

Polyamidoamine-polyethylene glycol (PAMAM-PEG) copolymers were synthesized using IPDI as coupling reagent by two-step method. The copolymers were characterized by IR spectrum and 1H NMR spectrum, and the PEG conjugating ratios of the copolymers were calculated equal to 10% and 30% separately. MTT assay indicated that after PEGylation a lower cytotoxicity of the copolymers could be found, and with increasing PEG conjugating ratio the cytotoxicity decreased obviously. Agarose gel retardation assay demonstrated that PAMAM-PEG copolymers could be combined with DNA and PAMAM-PEG/DNA complexes were prepared by self-assembly. DLS measurement showed that when N/P > or = 50, the particle size of copolymer/ gene complexes was in a range of 150-200 nm, and the zeta potential was in a range of 10-25 mV. In vitro gene transfection illustrated that when N/P < or = 50, the gene transfection efficiency of PAMAM-PEG copolymers was a little less than that of PAMAM-G5, but the transfection efficiency can be raised by increasing N/P ratio or transfection time. Considering both cytotoxicity and transfection efficiency aspects PAMAM-PEG-13 was more effect than PAMAM-PEG-39 in PEGylation.
Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Survival ; drug effects ; DNA ; chemistry ; pharmacology ; Dendrimers ; chemical synthesis ; pharmacology ; Gene Transfer Techniques ; Genetic Vectors ; Humans ; Isocyanates ; chemistry ; Liver Neoplasms ; pathology ; Particle Size ; Polyamines ; chemistry ; Polyethylene Glycols ; chemical synthesis ; chemistry ; pharmacology ; Transfection

OBJECTIVETo evaluate the inhibitory effects of survivin antisense oligonucleotide (survivin-ASODN) mediated by polyamidoamine dendrimer (PAMAM) against the growth of subcutaneously transplanted colorectal cancer in nude mice.

METHODSNude mouse models bearing colorectal cancer was established by subcutaneous injection of SW620 cells. Survivin- OSADN (300 microg/L) was mixed with 4.06 microg/L PAMAM or liposome to prepare two transfection complexes, and their morphologies were observed by transmission electron microscope. The particle size of the prepared complexes was determined by laser particle size analyzer, and the zeta potential was measured. The encapsulation efficiency and the DNA release rate in vitro were determined by ultraviolet spectrophotometer. The transfection complexes were then directly injected into the xenografts of the tumor-bearing nude mice. The tumor volume changes were observed, and the expression of survivin in the transplanted tumor was measured by Western blotting.

RESULTSThe PAMAM-survivin-ASODN complex had a significantly smaller diameter and greater zeta potential than liposome-survivin-ASODN (P<0.01 and 0.05, respectively). The encapsulation efficiency was comparable between the two complexes. In in vitro condition, PAMAM-survivin-ASODN allowed sustained survivin-ASODN release for as long as 14 days, as compared with the 5 days for the liposome complex. After injection into the tumor xenografts, PAMAM-survivin- ASODN resulted in significantly lower expression of survivin protein in the transplanted tumors (P<0.05), and also in significantly greater reduction of the tumor volume than the liposome complex (P<0.05).

CONCLUSIONPAMAM can effectively deliver survivin-ASODN into transplanted colorectal tumor cells to reduce the expression of survivin and inhibit the tumor growth.

Animals ; Cell Proliferation ; drug effects ; Colorectal Neoplasms ; pathology ; Dendrimers ; Humans ; Inhibitor of Apoptosis Proteins ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Microtubule-Associated Proteins ; genetics ; pharmacology ; Neoplasm Transplantation ; Oligonucleotides, Antisense ; pharmacology ; Polyamines ; pharmacology ; Repressor Proteins ; Tumor Cells, Cultured