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The aim of the present study was to determine whether combined administration of monoclonal antibody (Herceptin ® , trastuzumab) and anti-HER-2 (clone CB11) with hyaluronic acid (HA) and lipoplex (containing lipofectamine (LipA) and plasmid DNA) can produce a synergistic reaction to increase the therapeutic effect of monoclonal antibodies. To assess the treatment response, we cultured a 3-D MCF-7 cell line overexpressing HER-2 and CD44 receptors. The high density 3-D cell aggregation in the hollow fiber bioreactor (HFB) used for the cell culture was monitored with the use of proton magnetic resonance imaging ( 1 H MRI). In addition, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was used in combination with HPLC (high performance liquid chromatography) to evaluate structural changes in the proteins contained in treated cells. The study showed that incorporation of antibodies into targeted lipoplex results in more efficient delivery of the complex to tumor cells. The viability of cells decreased mostly due to cellular uptake of lipoplex and binding of the antibodies to the cellular surface receptor. The data also demonstrate that HA could be used to enhance treatment efficacy of trastuzumab and anti-HER-2 (clone CB11) in breast cancer cell cultures.

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Electrospray ionization (ESI-MS) and matrix assisted laser desorption-ionization (MALDI-MS) were used to determine the composition (monomer ratios) and structure (end group analysis) relative to 1H NMR spectroscopy and theoretical predictions for three different copolymers: poly(butyl acrylate/vinyl acetate) (PBA/PVAc), poly(methyl methacrylate/vinyl acetate) (PMMA/PVAc) and poly(butyl acrylate/methyl methacrylate) (PBA/PMMA). We found that the ESI results were in excellent agreement with 1H NMR spectroscopy for PBA/PVAc and PBA/PMMA copolymers whereas there was more divergence in the case of PMMA/PVAc. In the case of PBA/PMMA copolymers similar distributions of products were observe by ESI-MS and MALDI-MS with the two major products classes differing by their end-groups. One class has hydrogen and dodecylthio end groups while in the other the dodecylthio has been replaced by alpha-cyanoisopropyl from the initiator. The relative abundance of these distributions as a function of copolymer conversion for a series of reaction conditions was investigated by both ESI and MALDI. MALDI results consistently underestimated (relative to ESI) the butylacrylate monomer ratio in PBA/PMMA and the abundance of co-polymer oligomers terminated by a dodecylthio group from the chain transfer agent.

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