الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
In this work, different generations of polyamidoamine (PAMAM) cationic surfactants were prepared using piperazine as core center molecule and ethylene diamine as a repeated unit. These new surface-active materials were prepared via alternative steps of aza Michael addition reaction (of piperazine as core center molecule) and amidation reaction (by ethylene diamine). Each step was followed by quaternization using alkyl bromide with different chain length (4, 8 or 12 carbon atoms).
Spectroscopic data including FTIR, 1H-NMR and Elemental analysis confirmed the chemical structures of the prepared compounds.
The surface activity of the prepared compounds was evaluated using surface tension technique. The surface parameters including surface and interfacial tension, emulsification power, critical micelle concentration, effectiveness, efficiency, maximum surface excess and minimum surface area were determined at 25ºC. The thermodynamic parameters including standard free energy change (ΔGº) of both adsorption and micellization were calculated at 25ºC. from the results, we found that the amphiphilic dendrimers adsorb and orient themselves efficiently at the air / water interface as known for conventional surfactants in spite of the bulky dendron structure connected to an alkyl ammonium group. The surface activity of the quaternized cationic surfactant was found to be dependent on the dendrimer generation and alkyl chain length of the prepared surfactants.
In addition, all the prepared surfactants were evaluated as biocides against different bacterial and fungal species as well as against sulfate reducing bacteria (SRB). Most of the synthesized polyamidoamine cationic surfactants have significant biocidal activity against Gram +ve, Gram –ve bacteria and different fungal species as well as sulfate reducing bacteria (SRB), it is confident to say that a plurality of cationic moieties plays an important role in antimicrobial activity.
All the prepared polyamidoamine cationic surfactants were applied as anti-cancer agents against breast cancer cell line (MCF_ 7). Most of the synthesized polyamidoamine cationic surfactants showed good cytotoxic activity. Also, the relationship between the alkyl chain length and the cytotoxicity of breast cancer was not linear.
Finally, these compounds were applied in drug delivery by solubilization of a hydrophobic drug, where the synthesized surfactants showed high solubility for Coenzyme Q10 drug as a hydrophobic drug when compared with water. Then we studied the
dissolution of Coenzyme Q10 using the prepared surfactants and compared the results with two commercial surfactants (CTAB and labrasol. The results showed that the synthesized surfactants have high effect in dissolution study of Coenzyme Q10. In addition, we studied the dissolution of Ledipasvir and compared it with standared dissolution medium of FDA (Food and Drug Administration). The results showed the same effect of the synthesized surfactants with the standard FDA medium.
Finally, according to the toxicity test, the prepared materials are safe and recommended for use in the medical field.