## 3 Results and Discussion
### Wettability Study  
The wettability of the electrospun membranes was evaluated through static water contact angle measurements, offering insights into surface hydrophilicity and potential interactions with osteoblasts. All tested samples exhibited hydrophobic characteristics to varying degrees (Table 12). While PLA is sometimes described as moderately hydrophilic due to its polar ester groups, in fibrous membrane form, it often displays hydrophobic behavior due to surface roughness and limited surface energy [19]. Hydrophobic surfaces can resist moisture absorption, helping preserve structural and mechanical integrity under physiological conditions, which may be advantageous for long-term implant stability [20]. Additionally, reduced bacterial adhesion on hydrophobic surfaces has been noted as beneficial for minimizing infection risks in orthopedic applications [21]. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample** & **Droplet** & **Angle**\({}^{\circ}\) \\ \hline
1 & 110\({}^{\circ}\) \\ \hline
2 & 2 & 107\({}^{\circ}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 12: Wettability. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample** & **Droplet** & **Angle**\({}^{\circ}\) \\ \hline
3 & & 125\({}^{\circ}\) \\
4 & & 125\({}^{\circ}\) \\
5 & & 137\({}^{\circ}\) \\
6 & & 120\({}^{\circ}\) \\
7 & & 138\({}^{\circ}\) \\
8 & & 138\({}^{\circ}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 12: Cont. The pure PLA membranes (sample 1) demonstrated a contact angle of 110\({}^{\circ}\), confirming their high hydrophobicity. This level of surface tension can hinder initial protein adsorption and osteoblast adhesion, consistent with earlier studies showing reduced cell attachment on untreated PLA scaffolds [18; 22]. To enhance hydrophilicity, MgO nanoparticles were introduced into samples 2-4. However, no significant reduction in contact angle was observed, suggesting that MgO alone did not sufficiently alter the surface chemistry or morphology to affect wettability. Despite MgO's inherently hydrophilic nature, its effect may have been limited by partial embedding within the PLA matrix, restricting exposure at the fiber surface--a phenomenon previously reported by [PERSON] et al. [22]. Gold nanoparticle (AuNP) incorporation (samples 5-7) also did not yield a reduction in contact angle, with values ranging from 120\({}^{\circ}\) to 138\({}^{\circ}\). These results align with observations by [PERSON] et al. [11], who noted that AuNP surface effects depend on particle morphology and distribution. The metallic nature and surface energy of AuNPs can vary depending on their stabilization and interaction with surrounding matrix components. Notably, the PLA/MgO/AuNP hybrid membranes (samples 8-10) exhibited significantly improved hydrophilicity. Sample 10 showed the lowest contact angle of 59\({}^{\circ}\), indicating a marked increase in surface energy and water affinity. This dramatic change supports a synergistic interaction between MgO and AuNPs, where their combined effects modify the surface microstructure and chemistry in a more favorable manner for cell attachment. Similar synergy has been reported by [PERSON] et al. [18], where dual-inorganic modifications enhanced surface wettability and subsequent biological responses. \begin{table}
\begin{tabular}{c c c} \hline
**Sample** & **Droplet** & **Angle**\({}^{\circ}\) \\ \hline
8 & & 129\({}^{\circ}\) \\
9 & & 128\({}^{\circ}\) \\
10 & & 59\({}^{\circ}\) \\ \hline \end{tabular}
\end{table} 
Table 12: Cont. Overall, the average contact angle across all samples (excluding sample 10) was 124\({}^{\circ}\) with a standard deviation of 10.65, reaffirming the predominantly hydrophobic nature of the unmodified and singly modified membranes. The significant reduction in contact angle in sample 10 highlights the effectiveness of dual functionalization in creating an osteoblast-compatible microenvironment.