Enhancing Biocompatibility and Biophysical Properties of Three-Dimensional Collagen Scaffolds Using Nonthermal Plasma...

Collagen-glycosaminoglycan (CG) scaffolds are extensively utilized in tissue engineering for their excellent biocompatibility and low immunogenicity; however, their poor mechanical stiffness typically requires further physical or chemical modifications to enhance their structural integrity for clinical applications. We investigate the effects of nonthermal plasma (NTP) treatment; an emerging technology commonly used in the biomedical field for surface modifications, sterilization, and wound healing. A comprehensive analysis is conducted to evaluate the surface characteristics, biophysical properties, and biocompatibility of the 3D CG scaffolds treated with NTP for 2 and 5 min, compared with untreated controls. Histological and SEM analyses demonstrated thickening of the scaffold pore struts and an increase in porosity, while Energy Dispersive X-ray Spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) confirmed that the native chemical composition of the scaffolds remained intact and unchanged following NTP exposure. Post-treatment, the scaffolds exhibited increased hydrophilicity demonstrated by a reduced contact angle. Mechanical testing showed significant improvements in the scaffold's compression modulus, with increases of approximately 16.7% and 14.5% for 2 min and 5 min treatments, respectively (p < 0.05). In vitro biocompatibility assays indicated increased metabolic rates and significantly higher cell numbers in the ADSC-seeded on NTP-treated scaffolds (p = 0.001; p = 0.02, respectively). Following 21 day osteogenic conditions, both 2 min and 5 min NTP-treated scaffolds exhibited significantly elevated expression of key osteogenic markers, with RUNX2 showing a 9-fold increase at 2 min and an 11-fold increase at 5 min (p < 0.001), and Osteocalcin demonstrating increases of 2.5-fold and 2.3-fold, respectively (p < 0.01), compared to untreated controls. The enhanced biocompatibility and ability to serve as a supportive matrix that promotes osteogenic lineage commitment observed in the NTP-treated scaffolds suggest that these materials could be effectively utilized as allogenic osteocyte-loaded biomaterials for bone regeneration. Collectively, these results demonstrate that NTP treatment significantly improves the functional performance and mechanical strength of the 3D CG scaffolds, establishing it as an effective approach for enhancing scaffold performance in regenerative medicine applications.