Synthesis of polyamidoamine dendrimers for encapsulating natural products for potential anticancer enhancement

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Date
2015
Journal Title
Journal ISSN
Volume Title
Publisher
University of Dar es Salaam
Abstract
Generation four (G4) polyamidoamine (PAMAM) dendrimers containing ethylenediaminetetraacetic acid (EDTA) core was designed and synthesized through divergent approach. The dendrimer G4 was used for the encapsulation of a flavonoid tetramethylscutellarein (TMScu, 45) in order to study its solubility and in vitro release as potential anticancer activity enhancement. Compound 45 and the other selected natural products (compounds 9, 35, 46 and 47) were also studied by molecular docking modelling to simulate their encapsulation on dendrimer G4. The synthesized dendrimers and TMScu (45)-dendrimer complex were characterized by FTIR, UV-VIS, MALDI-TOF-MS and NMR. The encapsulation of compound 45 was achieved by a co-precipitation method with encapsulation efficiency and loading capacity 77.78 ± 0.69% and 6.22 ± 0.06%, respectively. Phase solubility diagram indicated PAMAM dendrimer to increase the aqueous solubility of TMScu (45) as a function of dendrimer concentration at pH 7. In vitro release studies of TMScu (45) the complex indicated high percentage at pH 4 where 75% was released from the complex, while at pH 7 the compound remained relatively stable with only 22% released. The stability of the TMScu-dendrimer was done under dark and light conditions with different temperature settings (0, 27 and 40 °C). It was observed that formulations stored in cool and dark places were stable compared to those stored under light and at higher temperatures. Molecular docking indicated that Tou-A (35)-PAMAM-G4 had higher pose energy, followed by 9-PAMAM-G4, 45-PAMAM-G4 and 46-PAMAM-G4, whereas 47-PAMAM-G4 had the lowest stability. Therefore, PAMAM dendrimer G-4 could act as a delivery system and potentiate their bioactivities.
Description
Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF QD381.9.S87S52)
Keywords
Dendrimers, Molecular structure
Citation
Shadrack, M. (2015) Synthesis of polyamidoamine dendrimers for encapsulating natural products for potential anticancer enhancement, Master dissertation, University of Dar es Salaam, Dar es Salaam