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- Sargassum muticum and Osmundea pinnatifida enzymatic extracts: chemical, structural, and cytotoxic characterizationPublication . Rodrigues, Dina; Costa-Pinto, Ana R.; Sousa, SĂ©rgio; Vasconcelos, Marta W.; Pintado, Manuela M.; Pereira, Leonel; Rocha-Santos, Teresa A. P.; Costa, JoĂŁo P. da; Silva, Artur M. S.; Duarte, Armando C.; Gomes, Ana M. P.; Freitas, Ana C.Seaweeds, which have been widely used for human consumption, are considered a potential source of biological compounds, where enzyme-assisted extraction can be an efficient method to obtain multifunctional extracts. Chemical characterization of Sargassum muticum and Osmundea pinnatifida extracts obtained by Alcalase and Viscozyme assisted extraction, respectively, showed an increment of macro/micro elements in comparison to the corresponding dry seaweeds, while the ratio of Na/K decreased in both extracts. Galactose, mannose, xylose, fucose, and glucuronic acid were the main monosaccharides (3.2â27.3 mg/glyophilized extract) present in variable molar ratios, whereas low free amino acids content and diversity (1.4â2.7 g/100gprotein) characterized both extracts. FTIR-ATR and 1H NMR spectra confirmed the presence of important polysaccharide structures in the extracts, namely fucoidans from S. muticum or agarans as sulfated polysaccharides from O. pinnatifida. No cytotoxicity against normal mammalian cells was observed from 0 to 4 mglyophilized extract/mL for both extracts. The comprehensive characterization of the composition and safety of these two extracts fulfils an important step towards their authorized application for nutritional and/or nutraceutical purposes.
- Sardine roe as a source of lipids to produce liposomesPublication . Guedes, Marta; Costa-Pinto, Ana Rita; Gonçalves, VirgĂnia; Moreira-Silva, Joana; Tiritan, Maria; Reis, Rui L.; Ferreira, Helena; Neves, Nuno M.Sea-derived materials have promising applications in the medical, pharmaceutical, and biotechnological fields. Fish roe, for example, is a highly nutritional product, presenting diverse beneficial effects on human health. Therefore, this work explored extracts of sardine (Sardina pilchardus) roe, due to the well-known health benefits of this fish, to produce novel and promising delivery systems. After morphological, histological, and histochemical characterizations of sardine roe, their lipids were extracted using two different approaches, namely, Bligh and Dyer (BD) and methyl-tert-butyl ether (MTBE) methods. Gas chromatography/mass spectrometry analyses demonstrated that lipid extracts contain several fatty acids, such as Ï3 polyunsaturated fatty acids. The lipids, especially phospholipids, were used to produce multilamellar liposomes (MLVs). These delivery systems presented size heterogeneity, a negative surface charge, and the ability to control the release of the encapsulated anti-inflammatory drug, namely, celecoxib. Biological assays indicated that MLVs produced with MTBE lipidic extracts presented a better cytocompatibility than those obtained by the BD method. This can be further improved if the lipid extracts are processed by chemical extraction. Therefore, sardine roe-derived lipids can produce drug-delivery systems with the potential to be applied in the biomedical field.
- Assessment of baby Bibs. GC-MS screening, migration into saliva and insight of toxicity with QSAR toolsPublication . Rajbux, Chandisree; Pereira, Joel; Selbourne, Maria do Céu; Costa-Pinto, Ana Rita; Poças, FåtimaPlastic baby Bibs are, according to the European legislation, food contact materials. Therefore, compositional and migration limits applicable to plastics should be observed. This work aimed at identifying potential migrants in Bibs from European market and determining the migration into artificial saliva. Bibs were subjected to screening analyses (GC-MS). Thirty substances non-authorised in European or Swiss legislation were detected: phthalates, light stabilizers, flame retardants and photoinitiators. Irgacure 184, Cyclohexanone, Tinuvin 770, Isophorone and 9-Octadecenamide, (Z)- were detected in saliva after contact with selected Bibs. The migration values render two samples noncompliant although results should be interpreted with caution given the experimental conditions. In order to gain insight on the toxicity of migrants, QSAR tools were applied. Substances non-evaluated or not-listed were analysed with free software regarding their Cramer class (ToxTree and their predicted mutagenicity, carcinogenicity and developmental toxicity (VEGA). Results indicate that surveillance is required: monitoring Bibs'compliance, application of GMPs and traceability.
- Ultrasound sonication prior to electrospinning tailors silk fibroin/PEO membranes for periodontal regenerationPublication . SerĂŽdio, Ricardo; Schickert, SĂłnia L.; Costa-Pinto, Ana R.; Dias, Juliana R.; Granja, Pedro L.; Yang, Fang; Oliveira, Ana L.In this study, silk fibroin (SF)/poly(ethylene oxide) (PEO) membranes were designed and fabricated by combining ultrasound sonication prior to electrospinning (0 to 20âŻmin) as a strategy to physically control the rheological properties of solutions (10 to 30% w/v PEO) and to improve the spinnability of the system. PEO has proved to be essential as a co-spinning agent to assure good membrane reproducibility and enough flexibility for clinical manipulation. The rheological tests indicated that sonication greatly increased the viscosity of SF/PEO solutions and further enhanced the quality of the produced electrospun fibers with consequent improved mechanical properties in dry and wet conditions. By tuning the viscosity of the solutions using a simple sonication step prior to electrospinning, it was possible to induce water stability in the as-electrospun matrix, as demonstrated by infra-red spectroscopy. This reduced complexity in the process since it was not necessary to concentrate silk prior to electrospinning while avoiding the use of toxic solvents to perform a post-processing stabilization treatment which usually causes dimensional changes to the SF materials. Sonication pre-treatment allowed for minimizing the amount of synthetic polymer used to achieve the desirable mechanical properties (with the modulus ranging between 90 and 170âŻMPa), while avoiding a further water stabilization treatment. It also had a positive impact in the in vitro cell behavior of human primary periodontal ligament cells (hPDLs), resulting in a marked increase in cell proliferation. The present developed work constitutes a step forward towards simplicity and a better fabrication control of viable electrospun SF-based membranes for periodontal regeneration.
- Chitosan and hydroxyapatite based biomaterials to circumvent periprosthetic joint infectionsPublication . Costa-Pinto, Ana Rita; Lemos, Ana LuĂsa; Tavaria, Freni KekhasharĂș; Pintado, ManuelaEvery year, worldwide, millions of people suffering from joint pain undergo joint replace-ment. For most patients, joint arthroplasty reduces pain and improve function, though a small fraction will experience implant failure. One of the main reasons includes prosthetic joint infection (PJI), involving the prosthesis and adjacent tissues. Few microorganisms (MO) are required to inocu-late the implant, resulting in the formation of a biofilm on its surface. Standard treatment includes not only removal of the infected prosthesis but also the elimination of necrotic bone fragments, local and/or systemic administration of antibiotics, and revision arthroplasty with a new prosthesis, immediately after the infection is cleared. Therefore, an alternative to the conventional therapeutics would be the incorporation of natural antimicrobial compounds into the prosthesis. Chitosan (Ch) is a potential valuable biomaterial presenting properties such as biocompatibility, biodegradability, low immunogenicity, wound healing ability, antimicrobial activity, and anti-inflammatory potential. Regarding its antimicrobial activity, Gram-negative and Gram-positive bacteria, as well as fungi are highly susceptible to chitosan. Calcium phosphate (CaP)-based materials are commonly utilized in orthopedic and dentistry for their excellent biocompatibility and bioactivity, particularly in the establishment of cohesive bone bonding that yields effective and rapid osteointegration. At present, the majority of CaP-based materials are synthetic, which conducts to the depletion of the natural resources of phosphorous in the future due to the extensive use of phosphate. CaP in the form of hydroxyapatite (HAp) may be extracted from natural sources as fish bones or scales, which are by-products of the fish food industry. Thus, this review aims to enlighten the fundamental characteristics of Ch and HAp biomaterials which makes them attractive to PJI prevention and bone regeneration, summarizing relevant studies with these biomaterials to the field.