Browsing by Author "Sousa, Aureliana"
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- Electrospun polycaprolactone (PCL) degradation: An in vitro and in vivo studyPublication . Dias, Juliana R.; Sousa, Aureliana; Augusto, Ana; Bártolo, Paulo J.; Granja, Pedro L.Polycaprolactone (PCL) is widely used in tissue engineering due to its interesting properties, namely biocompatibility, biodegradability, elastic nature, availability, cost efficacy, and the approval of health authorities such as the American Food and Drug Administration (FDA). The PCL degradation rate is not the most adequate for specific applications such as skin regeneration due to the hydrophobic nature of bulk PCL. However, PCL electrospun fiber meshes, due to their low diameters resulting in high surface area, are expected to exhibit a fast degradation rate. In this work, in vitro and in vivo degradation studies were performed over 90 days to evaluate the potential of electrospun PCL as a wound dressing. Enzymatic and hydrolytic degradation studies in vitro, performed in a static medium, demonstrated the influence of lipase, which promoted a rate of degradation of 97% for PCL meshes. In an in vivo scenario, the degradation was slower, although the samples were not rejected, and were well-integrated in the surrounding tissues inside the subcutaneous pockets specifically created.
- A single-component hydrogel bioink for bioprinting of bioengineered 3D constructs for dermal tissue engineeringPublication . Pereira, Rúben; Sousa, Aureliana; Barrias, Cristina C.; Bártolo, Paulo J.; Granja, Pedro L.Bioprinting is attractive to create cellularized constructs for skin repair. However, the vast majority of bioinks present limitations in the printing of chemically defined 3D constructs with controllable biophysical and biochemical properties. To address this challenge, a single-component hydrogel bioink with a controlled density of cell-adhesive ligands, tuneable mechanical properties and adjustable rheological behaviour is developed for extrusion bioprinting and applied for the biofabrication of 3D dermal constructs. A methacrylate modified pectin bioink is designed to allow the tethering of integrin-binding motifs and the formation of hydrogels by UV photopolymerization and ionic gelation. The rheological behaviour of a low polymer concentration (1.5 wt%) solution is adjusted by ionic crosslinking, yielding a printable bioink that holds the predesigned shape upon deposition for postprinting photocrosslinking. Printed constructs provide a suitablemicroenvironment that supports the deposition of endogenous extracellular matrix, rich in collagen and fibronectin, by entrapped dermal fibroblasts. This approach enables the design of chemically defined and cell-responsive bioinks for tissue engineering applications and particularly for the generation of biomimetic skin constructs.