## 3 Results and Discussion
### In Vitro Release of Shikonin  
Evaluations in terms of encapsulation efficiency (EE), drug-loading content (DLC) and the release profiles of LENMs are important for clinical applications. For the evaluations of the release file, there are two factors, including the total amount of the drug released as well as the rate of the release profile versus time. The method used in this study refers to [PERSON], [PERSON] et al. Results are expressed as the percentage of shikonin released in regard to the total entrapped drug (\(\text{C}_{\text{t}}/\text{C}_{\text{total entrapped shikonin}}\)) versus time, and as the % release of shikonin (\(\text{C}_{\text{t}}/\text{C}_{\text{total shikonin released}}\)) versus time (Figure 4) [11]. Figure 4 and Table 4 show that LENM-1, LENM-2, and LENM-3 can release 36-47% of SK in the first hour. Figure 4a shows that using a nanofibrous membrane as drug carrier can have a high specific surface area, which benefits the diffusion of SK from the surface and the highly porous structure. In comparison, [PERSON] et al. also indicated that an initial rapid release of the drug is followed by a second stage of a slower release until reaching a plateau at 48 h [18]. In particular, LENM-2 exhibited the maximum drug release amount in 48 h, and the total release amount in the 48 th h  
Figure 3: SEM images (5000\(\times\)) of (**a**) LENM-1; (**b**) LENM-2; and (**c**) LENM-3. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Samples**} & **Amount of Water** & **Amount of** & & **Electrical** & \\  & **Based PVA** & **Ethanol Based LE** & **Viscosity (cP)** & **Conductivity** & **Average** \\  & **Solution (\%)** & **Solution (\%)** & & **(\#S/cm)** & **Diameter (nm)** \\ \hline PENM-9 & 100 & 0 & \(1562\pm 31\) & \(551\) & \(316\pm 37\) \\ LENM-1 & 90 & 10 & \(1297\pm 83\) & \(403\) & \(279\pm 52\) \\ LENM-2 & 80 & 20 & \(1088\pm 72\) & \(288\) & \(272\pm 51\) \\ LENM-3 & 70 & 30 & \(760\pm 71\) & \(217\) & \(177\pm 45\) ** \\ \hline \hline \end{tabular} Note: Data shown as mean \(\pm\) SD. **\(p\)** \(<\) 0.01 vs. all. **\(p\)** \(<\) 0.01 vs. LENMs group (sample: LENM-1, LENM-II and LENM-III; solvent concentration: 90:10, 80:20 and 70:30).  
\end{table} 
Table 3: Properties of Lithospermum erythrohizon electrospun nanofibrous membranes (LENMs). was 79 \(\pm\) 5.5% (\(p\) < 0.05), followed by LENM-1 (71 \(\pm\) 7.9% in the 48 th h) and then LENM-3. LENM-3 showed an SK release amount of 58 \(\pm\) 4.0% in the eighth hour, and SK almost stopped releasing and reached an amount of 61 \(\pm\) 3.6% in the 48 th h. LENM-1 and LENM-2 both showed continuous drug release for 48 h; moreover, LENM-2 showed a greater release amount per unit time and the longest time for drug release. Table 4 shows the encapsulation efficiency (EE) and drug-loading content (DLC) of the three LENMs. The test results show that the blending ratio PVA solution to LE extract has a direct influence on the EE and DLC of LENMs. LENM-1 has the maximum EE of 92.5 \(\pm\) 9.5%, followed by LENM-2 (89.2 \(\pm\) 2.2%), while LENM-3 has the maximum DLC of 0.22 \(\pm\) 0.01%. Figure 3 and Table 4 show that increasing the LE solution changes the viscosity of the electrospinninging solution and increases the DLC of LENM. Meanwhile, it also causes flaws, beaded-shape nanofibers, and unnecessary consumption, eventually leading to a significant decrease in EE. In sum, LENM-1 was chosed to be used in the next discussion, as it has good fiber formation, small average diameter, as well as optimal EE and DLC. Figure 4: Drug release curve of LENMs representing (**a**) the percentage of shikonin released in regard to the total entrapped drug versus time, (**b**) the percentage of shikonin released in regard to the total released drug versus time.