Long-Term Results of Cell-Free Biodegradable Scaffolds for In Situ Tissue-Engineering Vasculature: In a Canine Inferior Vena Cava Model

Abstract

We have developed a new biodegradable scaffold that does not require any cell seeding to create an in-situ tissue-engineering vasculature (iTEV). Animal experiments were conducted to test its characteristics and long-term efficacy. An 8-mm tubular biodegradable scaffold, consisting of polyglycolide knitted fibers and an L-lactide and ε-caprolactone copolymer sponge with outer glycolide and ε-caprolactone copolymer monofilament reinforcement, was implanted into the inferior vena cava (IVC) of 13 canines. All the animals remained alive without any major complications until euthanasia. The utility of the iTEV was evaluated from 1 to 24 months postoperatively. The elastic modulus of the iTEV determined by an intravascular ultrasound imaging system was about 90% of the native IVC after 1 month. Angiography of the iTEV after 2 years showed a well-formed vasculature without marked stenosis or thrombosis with a mean pressure gradient of 0.51±0.19 mmHg. The length of the iTEV at 2 years had increased by 0.48±0.15 cm compared with the length of the original scaffold (2–3 cm). Histological examinations revealed a well-formed vessel-like vasculature without calcification. Biochemical analyses showed no significant differences in the hydroxyproline, elastin, and calcium contents compared with the native IVC. We concluded that the findings shown above provide direct evidence that the new scaffold can be useful for cell-free tissue-engineering of vasculature. The long-term results revealed that the iTEV was of good quality and had adapted its shape to the needs of the living body. Therefore, this scaffold would be applicable for pediatric cardiovascular surgery involving biocompatible materials.

Morphofunctional characterization of decellularized vena cava as tissue engineering scaffolds

“…Most synthetic scaffolds are produced with polyglycolic acid (PGA) and its variants, such as polyglycolic acid-poly-L-lactic acid (PGAPLLA), among others [7,25,32]. Scaffolds derived from these materials can be produced in a controlled way, in different shapes, and with different porosity coefficients.…”

Polymer-Based Reconstruction of the Inferior Vena Cava in Rat: Stem Cells or RGD Peptide?

“…Overall, our results are in line with those of Matsumura et al who evaluated cell-free scaffolds in the IVC and pulmonary valve locations in dogs and found endothelialization, vascular smooth muscle cell proliferation, and synthesis of an extracellular matrix. 33,34 Such remodeling of the matrix is a key process in vascular restoration and is impacted by the number and polarity of invading monocytes and macrophages. From this standpoint, PDO and PHVBB outperformed PU with regard to the predominance of infiltrating regulatory ED2 macrophages, a phenotype associated with less inflammatory tissue scarring and improved remodelling.…”

Scaffolds and Cell-Based Tissue Engineering for Blood Vessel Therapy

“…A well-formed vasculature without stenosis or thrombosis and with calcification was observed The cell-free vasculature had good quality and shape adaptation The construct was applicable to pediatric surgery Matsumura et al, 2012 Human AM Human ECs 1 Shear stress application maintained the intact monolayer of ECs in the vessel's lumen Lee et al, 2012a 2 ECs were aligned along the long axis parallel to blood flow 3 Shear stress also increased PECAM-1 and E-cadherin and integrin αγβ3 expression 4 The amniotic fluid tube reduced TEBV fabrication through sheet-based engineering into the defect area. The advantage of this approach is that it allows scientists to slowly transform the nanostructure of materials to a multifunctional vessel by balancing polymer degradation rates with ECM production and cellular infiltration.…”