Investigating the Effects of Bead Formation on the Physicochemical and Biological Properties of Electrospun Poly(lactic-co-glycolic Acid) (PLGA) Membranes: A Comparative Analysis

Abstract

This study investigates the impact of bead formation on the properties of electrospun poly(lactic-co-glycolic acid) (PLGA) membranes, particularly mechanical strength, uniformity, and cell adhesion, challenging the conventional belief that bead-free membranes are superior.Three types of PLGA membranes were fabricated: beaded (B), fibrous (F), and a mixed (M) configuration of beads and fibers. Morphological, chemical, and surface characteristics were analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and water contact angle measurements. Human dental pulp stem cells (DPSCs) were used to assess in vitro cell adhesion, proliferation, and viability across the different membrane types.SEM imaging revealed distinct morphologies among the different membranes produced via electrospinning. FTIR analysis revealed no significant differences in the chemical composition of the membranes. Contact angle measurements indicated that membranes B and M became more hydrophilic over time, while membrane F remained relatively hydrophobic. All membranes supported DPSCs growth, with membrane M facilitating deeper cell infiltration into the scaffold, indicating enhanced cell integration. Viability assays revealed no significant differences in cell proliferation after 7 days, demonstrating that bead presence did not impair cell growth.These findings suggest that bead formation in PLGA membranes may offer advantages, such as improved hydrophilicity and enhanced cell infiltration, without compromising cell viability. This study challenges the notion that bead-free membranes are inherently superior and highlights the potential of bead morphology in optimizing electrospun PLGA scaffolds for biomedical applications.

Fig. 1

( A ) Example of a successful electrospinning process of the synthetic polymer solution with the formation of the Taylor cone (white arrow) and the plume (yellow arrow). ( B – D ) Examples of unsuccessful processes, identified by the absence of a Taylor cone and/or the accumulation of material buildup at the needle tip.

Fig. 2

Morphologies of electrospun synthetic poly(lactic-co-glycolic acid) (PLGA) membranes by scanning electron microscopy (SEM). ( A ) Beads membrane exhibiting beads. ( B ) Fiber membrane. ( C ) Mixed (beads and fibers) membrane.

Fig. 3

Fourier-transform infrared spectroscopy (FTIR) analysis for the three poly(lactic-co-glycolic acid) (PLGA) membranes. ( A ) The bead membrane (membrane B). ( B ) The fiber membrane (membrane F). ( C ) The mixed membrane (membrane M).

Fig. 4

Contact angle measurements for the three poly(lactic-co-glycolic acid) (PLGA) synthetic membranes were taken at 30 minutes (left) and 60 minutes (right). The figure shows the wettability and surface properties of the membranes over time, indicating changes in hydrophobicity or hydrophilicity. Membranes B and M ( A and C ) exhibited higher hydrophobicity compared to membrane F ( B ) at 60 minutes.

Fig. 5

Scanning electron microscopy (SEM) images of dental pulp stem cells (DPSCs) seeded on poly(lactic-co-glycolic acid) (PLGA) membranes after 3 days. ( A ) Bead membrane (membrane B), ( B ) fiber membrane (membrane F), and ( C ) mixed membrane (membrane M).

Fig. 6

Immunofluorescence staining of dental pulp stem cells (DPSCs) cultured on the synthetic polymer membranes ( A–C ) for 48 hours. Cells' nuclei (blue) and mitochondria (green) are shown and demonstrate successful cell adhesion and spreading across all scaffold surfaces. Notably, membrane M (The mixed membrane) exhibited significantly enhanced cell growth and activity, evidenced by a densely populated layer of live cells. ( A ) The bead membrane (membrane B). ( B ) The fiber membrane (membrane F). ( C ) The mixed membrane (membrane M).

Fig. 7

Results of the XTT cell viability assay for dental pulp stem cells (DPSCs) cultured on the different poly(lactic-co-glycolic acid) (PLGA) membranes over 1, 3, and 7 days. A significant increase in cell number was observed from day 1 to day 7 across all groups. The control group showed significant differences compared to all membrane groups at all time intervals. No significant differences between the membrane groups at day 7. ( A ) The bead membrane (membrane B). ( B ) The fiber membrane (membrane F). ( C ) The mixed membrane (membrane M).