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- Corncob cellulose scaffolds: A new sustainable temporary implant for cartilage replacementPublication . Cordeiro, Rachel; Henriques, Marta; Silva, João C.; Antunes, Filipe; Alves, Nuno; Moura, CarlaTissue engineering using scaffolds is a promising strategy to repair damaged articular cartilage, whose self-repair is inefficient. Cellulose properties have been recognized for their application in the biomedical field. The aim of this study was to fabricate and characterize novel scaffolds based on poly(E-caprolactone) (PCL) and sustainable cellulose. Thus, the performance of corncob-derived cellulose (CC) in scaffolds as an alternative to wood cellulose (WC) was also investigated to reduce the environmental footprint. Two concentrations of CC in scaffolds were tested, 1% and 2% (w/w), and commercial WC using the same concentrations, as a control. Morphologically, all the developed scaffolds presented pore sizes of ~300 m, 10 layers, a circular shape and well-dispersed cellulose. Thus, all of these characteristics and properties provide the manufactured scaffolds suitable for use in cartilage-replacement strategies. The use of 2% CC results in higher porosity (54.24%), which promotes cell infiltration/migration and nutrient exchange, and has similar mechanical properties to WC. As for the effects of enzymatic degradation of the scaffolds, no significant changes (p > 0.05) were observed in resistance over time. However, the obtained compressive modulus of the scaffold with 2% CC was similar to that of WC. Overall, our results suggest that the integration of 2% corncob cellulose in PCL scaffolds could be a novel way to replace wood-cellulose-containing scaffolds, highlighting its potential for cartilage-replacement strategies.
- Recovery and evaluation of cellulose from agroindustrial residues of corn, grape, pomegranate, strawberry-tree fruit and favaPublication . Vallejo, Mariana; Cordeiro, Rachel; Dias, Paulo A. N.; Moura, Carla; Henriques, Maria; Seabra, Inês J.; Malça, C.; Morouço, PedroConsidering the expected increasing demand for cellulose fbers in the near future and that its major source is wood pulp, alternative sources such as vegetable wastes from agricultural activities and agro-food industries are currently being sought to prevent deforestation. In the present study, cellulose was successfully isolated from six agroindustrial residues: corncob, corn husk, grape stalk, pomegranate peel, marc of strawberry-tree fruit and fava pod. Cellulose fb ers were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, stereomicroscopy and scanning electron microscopy (SEM). Despite the evident morphological diferences among the extracted celluloses, results revealed similar compositional and thermal properties with the wood-derived commercial microcrystalline cellulose used as a control. Trace amounts of lignin or hemicellulose were detected in all cellulose samples, with the exception of corncob cellulose, that exhibited the greatest extraction yield (26%) and morphological similarities to wood-derived microcrystalline cellulose, visible through SEM. Furthermore, corncob cellulose was found to have ther mal properties (TOnset of 307.17 °C, TD of 330.31 °C, and ΔH of 306.04 kJ/kg) suitable for biomedical applications
- Biological Treatments for Temporomandibular Joint Disc Disorders: Strategies in Tissue EngineeringPublication . Trindade, Daniela; Cordeiro, Rachel; José, Henrique Cardoso; DF, Angelo; Alves, Nuno; Moura, CarlaThe temporomandibular joint (TMJ) is an important structure for the masticatory system and the pathologies associated with it affect a large part of the population and impair people’s lifestyle. It comprises an articular disc, that presents low regeneration capacities and the existing clinical options for repairing it are not effective. This way, it is imperative to achieve a permanent solution to guarantee a good quality of life for people who suffer from these pathologies. Complete knowledge of the unique characteristics of the disc will make it easier to achieve a successful tissue engineering (TE) construct. Thus, the search for an effective, safe and lasting solution has already started, including materials that replace the disc, is currently growing. The search for a solution based on TE approaches, which involve regenerating the disc. The present work revises the TMJ disc characteristics and its associated diseases. The different materials used for a total disc replacement are presented, highlighting the TE area. A special focus on future trends in the field and part of the solution for the TMJ problems described in this review will involve the development of a promising engineered disc approach through the use of decellularized extracellular matrices.
- Preserving and hydrogel-matrixing the bioactive properties of aromatic medicinal halophytic herbs from the coastline of the Iberian PeninsulaPublication . Parracho, Tiago; Cruz, Pedro F.; Peralta, Claúdia C.; Silva, Cândida G.; Campos, Maria Jorge; Neves, Marta; Cordeiro, Rachel; Trindade, Daniela; Moura, Carla; Almeida, Zaida L.; Pereira, Cidália D.; Guimarães, Carla; Brito, Rui M. M.; Guerra, Mauro; Reboredo, Fernando; Veríssimo, Paula; Vaz, Daniela C.; Santos Ribeiro, VâniaEdible wild plants are part of the ethnobotanic heritage of a certain geographical area and are important sources of essential oils, antioxidants, minerals, and special flavours. Corema album (Portuguese crowberry), Crithmum maritimum (sea fennel), Eryngium maritimum (sea holly), Helichrysum italicum (curry plant) and Otanthus maritimus (cottonweed) wildly flourish along the sandy dunes of the coast of the Iberian Peninsula. These plants are locally known for their beneficial properties, with important value for food, cosmetics and/or medicinal applications. Hence, leaves of these endemic species were collected at four different locations and submitted to different preserving treatments (oven-drying, freezing, and freeze-drying). Acetonic extracts of the different plants submitted to the different post-harvesting treatments were analysed regarding their antioxidant capacities and phenolic contents. Plant extracts were also analysed by diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR). In general, freeze-drying was the best method of preserving plant minerals, antioxidants (~4 mgVCEAC/g fw) and polyphenols (~5 mgGAE/g fw). Minerals were quantified via energy-dispersive X-ray fluorescence spectrometry, and despite their location, all plants were rich in Ca, Cl, K, S and P. Hierarchical clustering and principal component analyses (PCA) pointed towards chemical/metabolic proximity between taxonomic families. Alginate hydrogels loaded with 0.1 % and 0.2 % (w/v) of extracts presented homogenous surface properties by scanning electron microscopy, good mechanical tensile strength (~30 MPa) and antibacterial activity against S. aureus. Edible alginate hydrogels enriched with plant extracts hold great nutraceutical potential to be used as natural preservatives for food coating and packaging or as sources of bioactive compounds for biomedical applications.