Effects of lamellar microstructure of retinoic acid loaded-matrixes on physicochemical properties, migration, and neural differentiation of P19 embryonic carcinoma cells

Abstract

In this study, retinoic acid loaded-PLGA-gelatin matrixes were prepared with both freeze-casting and freeze-drying techniques. Herein, the effect of unidirectional microstructure with tunable pores on release profile, cellular adhesion, migration, and differentiation was compared. Morphological observation determined that highly interconnected porous structure can be formed, but lamellar pore channels were observed in freeze-casting prepared constructs. The absorption ratio was increased, and the biodegradation rate was decreased as a function of the orientation of microstructure. The in-vitro release study illustrated non-Fickian release mechanism in both methods, so that erosion has predominated over diffusion. Accordingly, PLGA-gelatin scaffolds prepared with freeze-drying technique showed no adequate erosion due to the rigid structure, while freeze-casting one presented more favorable erosion. Microscopic observations of adhered P19 embryonic cells on the scaffolds showed that the freeze-casting matrixes with unidirectional pores provide a more compatible microenvironment for cell attachments and spreading. Besides, it facilitated cell migration and penetration inside the structure and may act as guidance for neuron growth. Improvement in the expression of neural genes in unidirectionally oriented pores proved the decisive role of contact guidance for nerve healing. It seems that the freeze-cast PLGA-gelatin-retinoic acid scaffolds have initial features for nerve tissue regeneration studies.

Applications of Polydopamine in Implant Surface Modification

“…Lee et al [33] developed a hydroxyapatite collagen calcium silicate-polydopamine (HCCS-PDA) biomaterial to repair critical size bone defects; they found that the flexural strength of HCCS-PDA was higher than that of HCCS after PDA modification. Ghorbani et al [28] found that the tensile strength and Young's modulus of polyvinyl alcohol /polyurethane -polyaniline matrices with PDA were increased, which is indicative of the potential of application processes in bone tissue engineering.…”

“…Xi et al [28] reported that the membranes of porous polymers became smoother after poly(3,4-dihydroxyphenylalanine) coating. Conversely, poly(L-lactide-co-caprolactone)film surfaces transitioned from smooth to rough.…”