A novel poly (vinyl alcohol)/poly (ethylene glycol) scaffold for tissue engineering with a unique bimodal open-celled structure fabricated using supercritical fluid foaming

Abstract

In this study, a novel poly (vinyl alcohol) (PVA)/poly (ethylene glycol) (PEG) scaffold was carefully designed via thermal processing and subsequent supercritical fluid (SCF) foaming. Interestingly, a bimodal open-celled structure with interconnected networks was successfully created in the plasticized PVA (WPVA)/PEG scaffold. Large cells were produced from the nucleation sites generated in the PVA phase during rapid depressurization, while plenty of small pores generate in the cell walls of the big cells. The formation mechanism of this cellular structure was studied by considering the various phase morphologies and the diffusion behaviour of the carbon dioxide (CO 2 ) in individual phases. In addition, the intermolecular interactions of the WPVA/PEG blend were studied using X-ray diffraction and FTIR analysis. The results demonstrate that various types of hydrogen bonds among the hydroxyl groups on the PVA chains, PEG and water molecules are formed in the blend system. The realization of thermoplastic foaming of the PVA/PEG blend benefits from the interactions of complexation and plasticization between water and PEG molecules. The SEM images also revealed that L929 fibroblast cells were able to attach and spread on surfaces of the WPVA/PEG samples. Thus the WPVA/PEG scaffold with unique bimodal cellular structure is nontoxic and favours the attachment and proliferation of cells, making it promising for use as the candidate for tissue engineering applications.

Modulation of Cell Behavior by 3D Biocompatible Hydrogel Microscaffolds with Precise Configuration

“…Substrate topology clues can significantly affect the shape of the cell, as well as attachment, migration, differentiation, etc. The L929 cells on the flat substrate appear in a strap-like shape, as Liu reported on a poly (vinyl alcohol)/poly (ethylene glycol) surface [ 44 ]. Cells cultured on the line array were oriented in alignment along the space formed between two struts, which was similar to the phenomena previously reported [ 45 ], appearing in a strip shape.…”

Facile Fabrication of Polyvinyl Alcohol/Edge-Selectively Oxidized Graphene Composite Fibers

“…The PVA-only fibers and PVA composite fibers prepared in this work exhibited high crystallinity compared with PVA films [22] because they were highly drawn. The XRD peaks at about 11.4°, 19.7°, and 22.7° were assigned to the crystal faces of (100), (101), and (200), respectively [23,24]. The XRD patterns of the PVA/EOG composite fibers were similar to that of the PVA-only ones, indicating that the EOG incorporation did not decrease the fiber crystallinity.…”

Recent progress on polymer scaffolds production: Methods, main results, advantages and disadvantages

“…Figure 1c shows a schematic representation of the gas foaming process. CO 2 is usually approved in the gas foaming process due to its non-toxicity, non-flammability, chemical stability, and less demanding supercritical conditions (critical temperature = 31 °C and pressure = 7.38 MPa) [40]. CO 2 interacts with different polymers, even at low pressures, and contributes to plasticization.…”

“…Another study developed a bimodal structure of poly (vinyl alcohol) (PVA)/PEG scaffold for tissue engineering [40]. As aforementioned, the hierarchical pore structure is critical in seeding and cell adhesion, as well as the interconnected network, which permits an easy diffusion of nutrients and wastes in the cellular cycle.…”