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Three new cardenolides (3, 9 and 10), along with eight known ones, were isolated from the latex of Calotropis procera. The structural determination was accomplished by the 1D- and 2D-NMR spectra as well as HRESIMS analysis. The growth inhibitory activity of the latex and its sub-fractions as well as isolated compounds was evaluated against human A549 and Hela cell lines. The results exhibited that latex had strong growth inhibitory activity with IC50s of (3.37 lM, A-549) and (6.45 lM, Hela). Among the four extracts (hexane, chloroform, ethyl acetate and aqueous), chloroform extract displayed the highest potential cytotoxic activity, with IC50s of (0.985 lM, A-549) and (1.471 lM, Hela). All the isolated compounds displayed various degrees of cytotoxic activity and the highest activity was observed by calactin (1) with IC50s values of (0.036 lM, A-549) and (0.083 lM, Hela). None of these isolated compounds exhibited good antimicrobial activity evaluated by determination of their MICs using the broth microdilution method against various infectious pathogens. The structure–activity relationships for cytotoxic activity were also discussed.

Purpose: To develop a safe, lipid-based non-viral gene delivery system that achieves high transfection efficiency in the presence of serum proteins. Methods: Polyplexes with the pAcGFP1-C1 plasmid were formed in phosphate buffered saline, pH 7.4 (PBS) using the novel poly[N-(2-hydroxypropyl)methacrylamide]-poly(N,N-dimethylaminoethylmethacrylate) diblock copolymer (pHPMA-b-pDMAEMA) at N/P=4. Cationic-Liposomes were prepared from a dried lipid film comprised of equimolar 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 1,2-dioleoyl-sn-glycero-3- phosphoethanolamine (DOPE). Lipopolyplexes were fabricated at lipid/DNA weight ratios up to 40. Particle size distribution and zeta potential of lipopolyplexes were determined by dynamic light scattering. HeLa cells viability in the presence and absence of lipopolyplexes was quantified using the CellTiter-Glo® luminescent assay. HeLa cell transfection efficiency in the presence and absence of FBS was visually assessed by confocal microscopy and quantitatively compared to the TurboFect™ control. Results: pHPMA-b-pDMAEMA exhibited a high condensation capacity of 1 µg of pDNA per 0.513 μg of polymer (N/P=1). Lipid-coating of polyplexes at lipid/DNA weight ratios up to 40 resulted in particle sizes +25 mV. Exposure to FBS significantly increased mean particle size to >300 nm, reduced zeta potential to -10 mV, and augmented polydispersity. Lipid coating of polyplexes only decreased HeLa cell viability at lipid/DNA ratios >20. HeLa transfection with lipopolyplexes was most effective at lipid/DNA = 20 and was significantly greater in the presence of FBS than measured for lipid-free polyplexes. Conclusion: Lipid coating of pHPMA-b-pDMAEMA/DNA polyplexes with an equimolar DOTAP/DOPE mixture at a lipid/DNA ratio = 20 effectively enhances in vitro transfection efficiency of HeLa cells in the presence of serum proteins.

Purpose: To develop a safe, lipid-based non-viral gene delivery system that achieves high transfection efficiency in the presence of serum proteins. Methods: Polyplexes with the pAcGFP1-C1 plasmid were formed in phosphate buffered saline, pH 7.4 (PBS) using the novel poly[N-(2-hydroxypropyl)methacrylamide]-poly(N,N-dimethylaminoethylmethacrylate) diblock copolymer (pHPMA-b-pDMAEMA) at N/P=4. Cationic-Liposomes were prepared from a dried lipid film comprised of equimolar 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 1,2-dioleoyl-sn-glycero-3- phosphoethanolamine (DOPE). Lipopolyplexes were fabricated at lipid/DNA weight ratios up to 40. Particle size distribution and zeta potential of lipopolyplexes were determined by dynamic light scattering. HeLa cells viability in the presence and absence of lipopolyplexes was quantified using the CellTiter-Glo® luminescent assay. HeLa cell transfection efficiency in the presence and absence of FBS was visually assessed by confocal microscopy and quantitatively compared to the TurboFect™ control. Results: pHPMA-b-pDMAEMA exhibited a high condensation capacity of 1 µg of pDNA per 0.513 μg of polymer (N/P=1). Lipid-coating of polyplexes at lipid/DNA weight ratios up to 40 resulted in particle sizes +25 mV. Exposure to FBS significantly increased mean particle size to >300 nm, reduced zeta potential to -10 mV, and augmented polydispersity. Lipid coating of polyplexes only decreased HeLa cell viability at lipid/DNA ratios >20. HeLa transfection with lipopolyplexes was most effective at lipid/DNA = 20 and was significantly greater in the presence of FBS than measured for lipid-free polyplexes. Conclusion: Lipid coating of pHPMA-b-pDMAEMA/DNA polyplexes with an equimolar DOTAP/DOPE mixture at a lipid/DNA ratio = 20 effectively enhances in vitro transfection efficiency of HeLa cells in the presence of serum proteins.