Surface modification of electrospun polycaprolactone and zein using cold atmospheric plasma for tissue engineering applications

Cell adhesion and proliferation of zein-based scaffolds in tissue engineering are restricted due to hydrophobicity and low surface energy, and they are not appropriate for cell culture. Polycaprolactone (PCL) and zein are two distinct polymers in terms of origin and function; they are synthetic and natural polymers, respectively. In addition, PCL and zein have hydrophobic and amphiphilic structures. In this study we applied cold atmospheric plasma (CAP) for 4 min and 8 min to compare the effect of CAP on morphology, biodegradation, wettability, and chemical and biological features of zein and PCL-based nanofibrous structures. Our results presented that the water contact angle (WCA) of both types of nanofibers decreased after 4 and 8 min of treatment; PCL and zein contact angles after 8 min of treatment were 31.9 ± 7° and 30.3 ± 5° respectively. Chemical characterization confirmed that nanofibrous scaffolds were changed while functional groups were formed on scaffolds. Although biodegradation and cell attachment of scaffolds improved after treatment, most biodegradation rates belong to zein-P 8m; meanwhile, different CAP treatments have no negative effect on cell viability. With suitable cell viability, the potentials of zein and PCL in tissue engineering scaffolds could be improved. Based on SEM images, unlike zein, the synthetic PCL nanofibers aggregated and melted after CAP treatment, and PCL nanofiber morphology altered after 8 min treatment. At the same time, the results of other characterizations for zein and PCL fibers were approximately similar.