Melt electrowriting of PLA, PCL, and composite PLA/PCL scaffolds for tissue engineering application

Abstract

Fabrication of well-ordered and bio-mimetic scaffolds is one of the most important research lines in tissue engineering. Different techniques have been utilized to achieve this goal, however, each method has its own disadvantages. Recently, melt electrowriting (MEW) as a technique for fabrication of well-organized scaffolds has attracted the researchers’ attention due to simultaneous use of principles of additive manufacturing and electrohydrodynamic phenomena. In previous research studies, polycaprolactone (PCL) has been mostly used in MEW process. PCL is a biocompatible polymer with characteristics that make it easy to fabricate well-arranged structures using MEW device. However, the mechanical properties of PCL are not favorable for applications like bone tissue engineering. Furthermore, it is of vital importance to demonstrate the capability of MEW technique for processing a broad range of polymers. To address aforementioned problems, in this study, three ten-layered box-structured well-ordered scaffolds, including neat PLA, neat PCL, and PLA/PCL composite are fabricated using an MEW device. Printing of the composite PLA/PCL scaffold using the MEW device is conducted in this study for the first time. The MEW device used in this study is a commercial fused deposition modeling (FDM) 3D printer which with some changes in its setup and configuration becomes prepared for being used as an MEW device. Since in most of previous studies, a setup has been designed and built for MEW process, the use of the FDM device can be considered as one of the novelties of this research. The printing parameters are adjusted in a way that scaffolds with nearly equal pore sizes in the range of 140 µm to 150 µm are fabricated. However, PCL fibers are mostly narrower (diameters in the range of 5 µm to 15 µm) than PLA fibers with diameters between 15 and 25 µm. Unlike the MEW process of PCL, accurate positioning of PLA fibers is difficult which can be due to higher viscosity of PLA melt compared to PCL melt. The printed composite PLA/PCL scaffold possesses a well-ordered box structure with improved mechanical properties and cell-scaffold interactions compared to both neat PLA and PCL scaffolds. Besides, the composite scaffold exhibits a higher swelling ratio than the neat PCL scaffold which can be related to the presence of less hydrophobic PLA fibers. This scaffold demonstrates an anisotropic behavior during uniaxial tensile test in which its Young’s modulus, ultimate tensile stress, and strain to failure all depend on the direction of the applied tensile force. This anisotropy makes the composite PLA/PCL scaffold an exciting candidate for applications in heart tissue engineering. The results of in-vitro cell viability test using L929 mouse murine fibroblast and human umbilical vein endothelial (HUVEC) cells demonstrate that all of the printed scaffolds are biocompatible. In particular, the composite scaffold presents the highest cell viability value among the fabricated scaffolds. All in all, the composite PLA/PCL scaffold shows that it can be a promising substitution for neat PCL scaffold used in previous MEW studies.

Detection of Limbal Stem Cells Adhered to Melt Electrospun Silk Fibroin and Gelatin-Modified Polylactic Acid Scaffolds

“…Similarly, studies concerning melt electrowriting of PLA reported difficulties in the accurate positioning of the PLA fibers due to high PLA viscosity [ 44 ]. Some authors reported the addition of sodium stearate to reduce the melt viscosity of PLA during electrospinning, which also resulted in a reduction of fiber diameter [ 45 ].…”

Smart Nanofiber Mesh with Locally Sustained Drug Release Enabled Synergistic Combination Therapy for Glioblastoma

“…PCL has a slow degradation property [ 47 ]; the most significant advantage of PCL prepared in our study is that they can release drugs in vitro for a long time (at least 35 days), which allows the maintenance of local drug therapy for a significantly longer period after cancer surgery. In addition, PCL is easy to be processed due to its good mechanical properties and is usually fabricated as an extremely thin and softer sheet [ 48 ]. This makes it compatible with the hard and soft tissues of the body, markedly mitigating the risk of poor wound healing and bleeding post-implantation.…”

Investigating the correlation between the protein adhesion simulation and the biocompatibility of polymeric substrate for skin-tissue-engineering applications

“…MTT, as a quantitative cell viability test, was used to study the cell compatibility of the scaffolds. 43 The samples were each placed in sterile 24-well plates and submerged in 70% ethanol solution for 3 h. Then each side of the samples was exposed to UV light for 1 hour. Afterwards, the samples were washed 3 times with sterile PBS, for 20 minutes each time.…”