# The Effect of Human Blood Plasma Conditioning Films on Platelet Tungsten Bag Surface Properties
## 3 Results
### Conditioning Film MATH Assay  
The effect of a human plasma CF on _Ser. marcescens_ (Figure 5a) lowered the polar energy of the cells. Both the acid (chloroform) and basic (ethyl acetate) hydrocarbons demonstrated a reduction in the percent adherence after exposing the cells to the CF (from 42.2% to 21.9% for chloroform and from 48.3% to 33.9% for ethyl acetate), demonstrating that the ability for the cell to donate and accept electrons had been reduced, but was still within the moderate adhesion range (between 10% and 55%). The highly hydrophilic properties of _Ser. marcescens_ did not change, with both non-polar hydrocarbons (decane and hexadecane) demonstrating almost no adherence (0.29% and 0.58% respectively).  
_S. epidermidis_ (Figure 5b) demonstrated a reduced adherence to both non-polar (decane and hexadecane) hydrocarbons and the polar hydrocarbon chloroform (reductions from 98.2%, 95.8% and 98.4% to 90.8%, 89.2% and 93.8% for decane, hexadecane and chloroform respectively), but the reductions were a trend and were not significant. As this was still classed as high adhesion (>55%), whilst the cells may be slightly less hydrophobic the changes were unlikely to affect the hydrophobicity or the electron donating properties. However, a significant increase in the adherence of _S. epidermidis_ to the basic hydrocarbons' ethyl acetate (30.67% without and 59.74% with the CF) signified that the cells ability to accept electrons had increased significantly, especially as the cells were classed as moderately adhered without the CF (between 10% and 55%) but strongly adhered with the CF (>55%).  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \(\Delta G\) & \(\gamma_{s}\) & \(\gamma_{s}\)_LW_ & \(\gamma_{s}\)_AB_ & \(\gamma_{s}\)**+** & \(\gamma_{s}\)\({}^{-}\) \\  & **m/m\({}^{2}\)** & **m/m\({}^{2}\)** & **m/m\({}^{2}\)** & **m/m\({}^{2}\)** & **m/m\({}^{2}\)** & **m/m\({}^{2}\)** \\ \hline Flat & \(-\)40.2 \(\pm\) 6.1 & 53.3 \(\pm\) 1.2 & 45.2 \(\pm\) 0.1 & 8.1 \(\pm\) 1.1 & 1.8 \(\pm\) 0.2 & 9.7 \(\pm\) 1.5 \\ \hline Flat 1 h Plasma & \(-\)**22.0 \(\pm\) 19.4** & 47.4 \(\pm\) 3.9 & 40.6 \(\pm\) 1.4 & 6.8 \(\pm\) 3.2 & 0.7 \(\pm\) 0.5 & **22.7 \(\pm\) 10.9** \\ \hline Flat 24 h Plasma & \(-\)**5.5 \(\pm\) 19.2** & 46.0 \(\pm\) 5.3 & 40.4 \(\pm\) 3.5 & 5.7 \(\pm\) 2.5 & 0.5 \(\pm\) 0.3 & **29.3 \(\pm\) 10.1** \\ \hline Flat 1 h Plasma + Se & \(-\)60.5 \(\pm\) 6.1 & 46.8 \(\pm\) 1.2 & 44.5 \(\pm\) 0.6 & 2.3 \(\pm\) 0.8 & 0.3 \(\pm\) 0.1 & 5.2 \(\pm\) 1.5 \\ \hline Flat 24 h Plasma + Se & \(-\)58.6 \(\pm\) 3.3 & 38.3 \(\pm\) 0.2 & 36.9 \(\pm\) 0.2 & 1.3 \(\pm\) 0.3 & 0.2 \(\pm\) 0.1 & 4.7 \(\pm\) 1.1 \\ \hline Flat 1 h Plasma + Sm & \(-\)**63.2 \(\pm\) 3.1** & 45.5 \(\pm\) 0.4 & 44.2 \(\pm\) 0.4 & 1.3 \(\pm\) 0.2 & 0.1 \(\pm\) 0.0 & 4.6 \(\pm\) 0.8 \\ \hline Flat 24 h Plasma + Sm & \(\mathbf{6.9\pm 7.9}\) & 38.7 \(\pm\) 1.1 & 36.8 \(\pm\) 0.9 & 1.9 \(\pm\) 0.9 & 0.0 \(\pm\) 0.0 & **32.2 \(\pm\) 4.0** \\ \hline \hline \end{tabular}
\end{table}
Table 3: Physicochemistry of the flat surface after applying 1 h or 24 h conditioning films of the bacteria alone, human plasma alone or a combination of bacteria and human plasma. Se denotes the bacteria _Staphylococcus epidermidis_ and Sm denotes _Serratia marcescens_ (_n_ = 5). Statistical differences were considered below the \(p\) < 0.05 confidence level and are highlighted in grey with bold text.