More specifically, optimally porous scaffolds provide channels for diffusion of exogenously delivered and endogenous cell-secreted bioactive factors, mechanical support for maintaining tissue dimensions, and an ECM-like environment ahead of native ECM production ( Hollister, 2005). 3D biocompatible scaffolds serve to provide cell support by facilitating native extracellular matrix formation, promoting cell growth, and if necessary, differentiation ( Kim et al., 2015 Li et al., 2019a). Tissue engineering involves reconstruction and/or functional recovery of malfunctioned tissue ( Amini et al., 2012 Dai et al., 2016 Han and Du, 2020). Our finding supports the potential for the printed scaffold’s use for in vitro engineering of bone and other tissues using ADSCs and potentially other human stem cells, as well as in vivo regenerative medicine. The reduced 3D graphene oxide (RGO)/Alg scaffold has good cytocompatibility and can support human ADSC proliferation and osteogenic differentiation. GO was chemically reduced with a biocompatible reductant (ascorbic acid) to provide electrical conductivity and cell affinity sites. Alg printing was enabled through addition of gelatin (Gel) that was removed after printing, and the 3D structure was then coated with graphene oxide (GO). Here, we describe a novel combination of graphene with 3D printed alginate (Alg)-based scaffolds for human adipose stem cell (ADSC) support and osteogenic induction. Graphene, as a two-dimensional (2D) version of carbon, has shown great potential for tissue engineering. Herein we combine cell sheet technology and electrospun scaffolding to rapidly generate circumferentially aligned tubular constructs of human aortic smooth muscles cells with contractile gene expression for use as tissue engineered blood vessel media.Tissue engineering, based on a combination of 3D printing, biomaterials blending and stem cell technology, offers the potential to establish customized, transplantable autologous implants using a patient‘s own cells. Smooth muscle cells cultured on micropatterned and N-isopropylacrylamide-grafted (pNIPAm) polydimethylsiloxane (PDMS), a small portion of which was covered by aligned electrospun scaffolding, resulted in a single sheet of unidirectionally aligned cells. Upon cooling to room temperature, the scaffold, its adherent cells, and the remaining cell sheet detached and were collected on a mandrel to generating tubular constructs with circumferentially aligned smooth muscle cells which possess contractile gene expression and a single layer of electrospun scaffold as an analogue to a small diameter blood vessel's internal elastic lamina (IEL). This method improves cell sheet handling, results in rapid circumferential alignment of smooth muscle cells which immediately express contractile genes, and introduction of an analogue to small diameter blood vessel IEL. The current gold standard in coronary artery bypass surgery is a blood vessel autograft where a vessel explanted from the patient is attached to the diseased artery in order to reroute blood around the obstruction and restore blood flow to the heart. However, this strategy is suboptimal due to second site morbidity, a limited supply of autografts, and loss of patency. Similarly, the use of synthetic grafts in coronary artery (and other small diameter arteries) augmentation is clinically unsuccessful due to loss of patency which occurs due to thrombus accumulation on the lumen of the graft. To address the current limitations in treating small diameter blood vessel disease, researchers in the medical community have strived to develop a tissue engineered small diameter artery for more than two decades. Įarly approaches towards blood vessel tissue engineering are termed “top down” approaches and are based on seeding cells on porous scaffolds or embedding cells in hydrogels to support the cells and achieve the formation of tubular tissue engineered constructs. However, the archetypal approach of using biodegradable scaffolds to provide initial strength for the newly constructed vessels raises concerns about foreign body reaction, inflammation and infection due to bacterial colonization.
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