## 3 Results and Discussion
### In Vitro Antibacterial Activity of the Electrospun Nonwoven Fabrics  
The antibacterial efficiency of the cotton gauze, PLA, and 5 HPO/PLA electrospun nonwoven fabrics against _Staphylococcus aureus_ and _Escherichia coli_ were tested. The results of the test are given in Table 1. The images of the petri dishes demonstrating antibacterial activity of samples have been given as Supplementary Materials (Figure S1).  
The cotton gauze and PLA electrospun nonwoven did not exhibit a growth inhibitory effect against _Staphylococcus aureus_ and _Escherichia coli_. However, the HPO/PLA electrospun nonwoven fabric exhibited a good growth inhibitory effect against _Staphylococcus aureus_ (>99.99) and _Escherichia coli_ (>99.99). The outcome is consistent with the literature that reported that the antimicrobial activity of the _Hyperic  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Samples**} & \multicolumn{2}{c}{**Reduction Rate (\%)**} \\ \cline{2-3}  & _Staphylococcus aureus_ & _Escherichia coli_ \\ \hline Cotton gauze & No Reduction & No Reduction \\ PLA & No Reduction & No Reduction \\
5 HPO/PLA & \textgreater{}99.99 & \textgreater{}99.99 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Antibacterial activity of the electrospun nonwoven fabrics.  
Figure 4: The thickness (**a**) and, air permeability (**b**) test results of PLA and HPO/PLA electrospun nonwoven fabrics.  
spun PEG-PCL membranes has good antibacterial activity against _Staphylococcus aureus_ and _Escherichia coli_. This result can be explained by the intrinsic antimicrobial properties of HPO. HPO contains naphthodianthrones, hypericin, hyperorin, and flavonoids, which are responsible for their antibacterial properties [36; 38; 40; 86]. HPO is a lipophilic compound that, has been demonstrated to disrupt cellular membranes in bacteria and fungi, hence inhibiting cellular respiration and ionic transport [87]. These findings support the contention that HPO/PLA electrospun nonwoven fabrics can be used as an antibacterial material in potential biomedical fields.  
_Hypericum perforatum_ oil has long been used as a traditional treatment method for wound treatment [30; 31; 32; 33; 86; 87]. _Staphylococcus aureus_ and _Escherichia coli_ are predominant pathogens in wounds, and the source of most pathogenic contamination has been reported to be associated with exogenous contamination from contaminated wound dressing devices from the hospital setting or with the patient's normal flora [88; 89; 90]. At this point, the antibacterial activity against _Staphylococcus aureus_ and _Escherichia coli_ of the HPO-loaded PLA electrospun nonwoven may be beneficial in the healing process. For example, in comparison with conventional dressings (cotton gauze), PLA electrospun nonwoven fabrics loaded with HPO eliminate the disadvantages of the lack of antibacterial properties. The HPO-loaded PLA electrospun nonwoven fabric is simple and low-cost to produce, using commercially available technologies. In our effort to develop a biomaterial for biomedical engineering, we prepared a green fibrous material based on PLA loaded with HPO, which was assessed for the first time for bactericidal properties. This study shows that more studies should be done to emphasize the positive effects of HPO and PLA on human health and the environment and to address their possible impact.  
Preliminary measurements of _Hypericum perforatum oil_-load poly(lactic acid) electrospun mat as an antibacterial material was performed in vitro analysis and this study investigated some performance properties required for its use as a textile material. Further research should include characterization of the _Hypericum perforatum oil_-load poly(lactic acid) electrospun in a clinical report to establish its practical application, and assessment of fiber-cell interaction and wound healing.