Polyamide-amine (PAMAM) dendrimer, a new hyperbranched macromolecular polymer, is considered an "artificial protein" by many scholars on account of its excellent chemical and biological characteristics. PAMAM has internal cavities and a large number of reactive terminal groups. These structures allow the polymer to be used as a bionic macromoleculethat could simulate the biomimetic mineralization of the natural organic matrix on the surface of tooth tissue. Specifically, PAMAM can beused as an organic template to regulate mineral nucleation and crystal growth; thus, the polymerisa more ideal dental restoration material than traditional allogenic materials. This article reviews research progress on thePAMAM-induced biomimetic mineralization of hard tooth tissues.
Amines ; Biomimetics ; Dendrimers ; Humans ; Nylons ; Tooth Remineralization

Dendrimers are hyperbranched, monodisperse and three dimensional macromolecules, which consist of an apolar core and polar shell have been referred to as "unimolecular micelles". This paper briefly describes the development and structural characteristics of dendrimers and also explains the feature of dendrimers as drug carrier and the dendrimer-drug interactions in details. Recently, dendrimers, which have attracted increasing attention for their applications in many fields such as drug targeted delivery systems and gene transfection, are becoming potential novel carriers.
Dendrimers ; chemistry ; Drug Delivery Systems ; Drug Design ; Polyamines ; chemistry

Polyamidoamine (PAMAM) dendrimers is synthesized by the American scientist, Tomalia, in 1985 and is now used widely in many fields such as gene carriers, photoelectric sensor, wastewater treatment, drug carriers and catalyst. The present paper mainly reviews the structure and methods of synthesis, celluar cytotoxicity, achievements of gene and drug carriers research, advancement and prospect of PAMAM as a carrier in glioma therapy. Besides, it also involves an outline for the future research of the radiotherapy for glioma.
Biocompatible Materials ; chemical synthesis ; chemistry ; Dendrimers ; chemical synthesis ; chemistry ; Drug Carriers ; Genetic Vectors

Pluronic modified polyamidoamine (PAMAM) conjugate (PF127-PAMAM) was prepared and the inhibiting effect of MDR against MCF-7/ADR was investigated with doxorubicin (DOX) as model drug. 1H NMR and FTIR spectra showed that the conjugate was synthesized successfully. Element analysis accurately measured that 27.63% amino of per PAMAM was modified by pluronic (PAMAM : PF127, 1 : 35.37 mole ratio). PF127-PAMAM showed an increased size and a reduced zeta potential compared to PAMAM. PF127-PAMAM had lower hemolytic toxicity and cytotoxicity due to the reduced zeta potential and the protection of PF127. Each PF127-PAMAM molecular could load 19.58 DOX molecules, and the complex exhibited sustained and pH-sensitive release behavior. PF127-PAMAM/DOX exhibited weaker cytotoxicity than free DOX in MCF-7 cells; while the complex showed much stronger reverse effect of drug resistance in MCF-7/ADR cells, and resistance reversion index (RRI) was as high as 33.15.
Dendrimers ; pharmacology ; Doxorubicin ; pharmacology ; Humans ; MCF-7 Cells ; drug effects ; Poloxamer ; pharmacology

Dendrimers are highly branched macromolecules that have attractive nano-sized architectures. It seems that they can enter various cells easily because of their unique nanostructures and chemical properties, which make them to be one of important candidates of non-virus carriers for drug delivery or gene therapy. However, the understanding of cytotoxicity and related mechanisms of dendrimers are still limited. In recent years there has been rapid increases of researches regarding the biological effects of dendrimers, including the interactions of dendrimers to cells, transport mechanisms, intracellular distribution and biodistribution in vivo, as well as improvement of biocompatibility of dendrimers by surface engineering. In this paper, recent advances in the investigations of biological effect and surface modification for the dendrimers as drug or gene delivery systems were reviewed.
Animals ; Dendrimers ; chemistry ; pharmacology ; Drug Carriers ; chemistry ; Drug Delivery Systems ; methods ; Humans ; Macromolecular Substances ; chemistry ; Nanostructures

OBJECTIVETo study the corneal penetration of PAMAM dendrimers-coated puerarin liposomes in rabbits.

METHODEvaluated PAMAM (G2, G3) dendrimers-coated puerarin liposomes were prepared and the in vitro transcorneal penetration were compared to puerarin drop solution and uncoated liposomes. The effect of different proportion of PAMAM to phospholipids in formulation on corneal penetration and the penetration parameters were investigated.

RESULTThe steady state fluxes and permeability coefficients of puerarin by PAMAM G2 (1.0%) and PAMAM G3 (0.5%) coated puerarin liposomes were greater than that by puerarin drop solution and uncoated liposomess (P < 0.01), meanwhile the PAMAM G2 (1.0%) and PAMAM G3 (0.5%) coated liposomes were better than other ratios of coated liposomes for improvement of corneal penetration (P < 0.01).

CONCLUSIONThe PAMAM coated liposomes is able to enhance the corneal penetration of puerarin and promising as an ocular drug carriers.

Animals ; Cornea ; metabolism ; Dendrimers ; chemistry ; metabolism ; In Vitro Techniques ; Isoflavones ; chemistry ; Liposomes ; chemistry ; metabolism ; Rabbits

The objective of this work is to evaluate the effect of polyamidoamine (PAMAM) dendrimers on electroosmotic flow (EOF) through skin. The effect of size and concentration of dendrimer was studied, using generation 1, 4 and 7 dendrimer (G1, G4 and G7, respectively). As a marker molecule for the direction and magnitude of EOF, a neutral molecule, acetoaminophen (AAP) was used. The visualization of dendrimer permeation into the current conducting pore (CCP) of skin was made using G4–fluorescein isothiocyanate (FITC) conjugate and confocal microscopy. Without dendrimer, anodal flux of AAP was much higher than cathodal or passive flux. When G1 dendrimer was added, anodal flux decreased, presumably due to the decrease in EOF by the association of G1 dendrimer with net negative charge in CCP. As the generation increased, larger decrease in anodal flux was observed, and the direction of EOF was reversed. Small amount of methanol used for the preparation of dendrimer solution also contributed to the decrease in anodal flux of AAP. Cross-sectional view perpendicular to the skin surface by confocal laser scanning microscope (CLSM) study showed that G4 dendrimer-FITC conjugate (G4-FITC) can penetrate into the viable epidermis and dermis under anodal current. The permeation route seemed to be localized on hair follicle region. These results suggest that PAMAM dendrimers can permeate into CCP and change the magnitude and direction of EOF. Overall, we obtained a better understanding on the mechanistic insights into the electroosmosis phenomena and its role on flux during iontophoresis.
Acetaminophen ; Dendrimers* ; Dermis ; Electroosmosis* ; Epidermis ; Fluorescein-5-isothiocyanate ; Hair Follicle ; Iontophoresis ; Methanol ; Microscopy, Confocal ; Skin*

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

BACKGROUND: Psoriasis is a chronic inflammatory skin disease that affects approximately 1~3% of the general population. OBJECTIVE: We performed cDNA microarray analysis with using the dendrimer labelling method to investigate the gene expression profile in the peripheral blood mononuclear cells (PBMCs) of psoriatic patients. METHODS: The peripheral blood mononuclear cells of 5 patients with psoriasis and 8 control subjects were used in the gene expression analyses of psoriasis. RESULTS: We identified 212 differentially expressed genes that showed at least a two-fold induction and/or reduction in psoriatic patients. Among those, 63 genes, including CD44, CD56 and IL7R, were induced, while 139 genes, including the sphingosine kinase 1 and p16-INK genes, were reduced in the psoriatic patients. CONCLUSION: We can speculate that these genes may have a role for the pathogenesis of psoriasis via their affecting different cellular functions. Our results suggest a possible mechanism by which activated immune cells migrate from the blood to the skin in psoriatic patients, and we provide novel putative targets for developing drugs to treat psoriasis
Cell Adhesion ; Dendrimers ; Gene Expression ; Humans ; Oligonucleotide Array Sequence Analysis ; Phosphotransferases ; Phosphotransferases (Alcohol Group Acceptor) ; Psoriasis ; Skin ; Skin Diseases ; Sphingosine ; Transcriptome