## 3 Discussion
In our research, GPP displayed a notable stimulating effect on COL1A1 expression in hPDL-MSCs over the 2-week culture time, significantly higher than VSCM's. Correspondingly, the previous study on PCL mixed with GE has reported an increase in COL1A1 expression in hMSCs within the first week of culture [36]. Angiogenesis is an essential prerequisite for periodontal regeneration because it is crucial for delivering oxygen and other biomolecules within the tissue [38]. As a crucial paracrine factor secreted by MSCs, VEGF-A effectively promotes angiogenesis and plays a regulatory role in bone formation [39]. In the current study, the expression levels of the VEGF-A gene were elevated in both material groups, with a more pronounced enhancement in the GPP group during the first week. This aligns with a prior study involving Poly (D, L-lactide-co-glycolide)/GE electrospun scaffolds, where the materials stimulated VEGF-A expression in dental follicle stem cells after 7 days [40]. Likewise, the histological observations have indicated that PCL/GE nanofibers contribute to new blood vessel formation at the periodontal defect site [41]. Intriguingly, the protein production levels diverged from gene expression levels, with the VSCM group consistently presenting a higher value of protein detection than the GPP group at all time points. We have attempted to evaluate the absorption and desorption of VEGF by both materials and got quite intriguing results. First, the amount of VEGF in a solution incubated for 6 h with both materials was higher than it was incubated without materials. This finding suggests that both GPP and VSCM seem to protect VEGF from degradation, and VSCM is superior in this ability. Furthermore, the amount of VEGF subsequently released within the next 24 h was significantly higher for VSCM than for GPP. The nature of this difference is unclear and can be explained by the lower ability of GPP to absorb VEGF, as well as by better VEGF release from VSCM. The difference in the releasing process between materials can be due to the strong electrostatic adsorption properties of the GPP electrospun materials [42]. The assorted levels of foreign body reactions or inflammatory responses triggered by external grafting materials are major constraints on their clinical application. IL-8 is a pro-inflammatory chemokine that plays a paramount role in recruiting neutrophils [43]. We found that both scaffolds positively modulated IL-8 gene expression and protein production, although this effect was not always statistically significant. It should be noted that a certain degree of inflammation is an essential part of the initial phase of regeneration and is essential in controlling infections. The major limitation of this study is in vitro design. Although both types of scaffolds showed promising potential for periodontal regeneration and clinical application, in vitro conditions cannot fully mimic the physiological environment of the inner periodontium structure. Consequently, further in vivo studies are required to verify these findings. Furthermore, the mechanisms by which fibrous materials regulate cellular behavior remain at a relatively rudimentary level. To explore deeper mechanisms, such as whether the discrepancy between results from different materials is due to integrin-mediated cascades or deformation of cell morphology, further specialized studies, which would offer more insight into the future optimization and modification of fibrous structures, are necessary.