Poly(trimethylene carbonate-co-L-lactide) electrospun scaffolds for use as vascular grafts

Abstract

Currently, there is great clinical need for suitable synthetic grafts that can be used in vascular diseases. Synthetic grafts have been successfully used in medium and large arteries, however, their use in small diameter vessels is limited and presents a high failure rate. In this context, the aim of this study was to develop tissue engineering scaffolds, using poly(trimethylene carbonate- co -L-lactide) (PTMCLLA), for application as small diameter vascular grafts. For this, copolymers with varying trimethylene carbonate/lactide ratios – 20/80, 30/70, and 40/60 – were submitted to electrospinning and the resulting scaffolds were evaluated in terms of their physicochemical and biological properties. The scaffolds produced with PTMCLLA 20/80, 30/70, and 40/60 showed smooth fibers with an average diameter of 771±273, 606±242, and 697±232 nm, respectively. When the degradation ratio was evaluated, the three scaffold groups had a similar molecular weight ( M w ) on the final day of analysis. PTMCLLA 30/70 and 40/60 scaffolds exhibited greater flexibility than the PTMCLLA 20/80. However, the PTMCLLA 40/60 scaffolds showed a large wrinkling and their biological properties were not evaluated. The PTMCLLA 30/70 scaffolds supported the adhesion and growth of mesenchymal stem cells (MSCs), endothelial progenitor cells, and smooth muscle cells (SMCs). In addition, they provided a spreading of MSCs and SMCs. Given the results, the electrospun scaffolds produced with PTMCLLA 30/70 copolymer can be considered promising candidates for future applications in vascular tissue engineering.

Electrospun Elastomeric Leaflet Substrates that Structurally and Mechanically Mimic Human Aortic Valve Leaflets

“…This observation could have been due to ECM production (as discussed in future sections) in the PCL/PTMC cell-cultured constructs, slightly increasing the mechanical properties. ,, Also, SEM imaging of the fibers in the PCL and PCL/PTMC constructs showed mild fiber degradation in the C-PCL/PTMC-LA layer, while no fiber degradation was observed in the PCL construct or the R-PCL/PTMC-CL layer of the PCL/PTMC construct (Figure c–f). This observation could be due to the relatively fast degradation of LA compared to CL and could have resulted in a mild decline in tensile properties in the circumferential direction of the PCL/PTMC constructs . However, after removing the ECM material from the PCL and PCL/PTMC constructs and weighing the acellular substrates after 1, 10, 20, and 30 days of cell culture, there was no change in the mass of the substrates (Figure g).…”

Small diameter vascular grafts: progress on electrospinning matrix/stem cell blending approach

“…Teeth that naturally fall off in children and wisdom teeth that need to be extracted in adults both contain abundant DPMSCs. Braghirolli et al found that copolymers with different trimethylene carbonate/lactide ratios ES SDVGs supported the adhesion and growth of DPMSCs, umbilical cord blood EPCs, and primary aortic SMCs, and promoted the differentiation of DPMSCs into vascular SMCs ( Braghirolli et al, 2019 ). The same group also evaluated the effect of DPMSCs on another kind of SDVGs composed of heparin/VEGF-modified PCL ES fibers.…”