248 research outputs found
Marine-derived biomaterials for cancer treatment
No full textCancer treatments do not achieve the desired therapeutic effects so far, mainly due to unwanted side effects, specifically the toxicity to healthy tissues. The use of natural compounds, namely marine-derived biopolymers, may offer a promising alternative which will be the main focus of this book chapter. Since fucoidan and chitosan have been reported to present anticancer activity as single bioactive agents, their use will be further explored and described in relation to their mechanisms of action. In addition, the use of the abovementioned polysaccharides, along with alginate and carrageenan, have been mostly explored for the development of drug-delivery systems which will be further analyzed. In the last section of this chapter, the development of three-dimensional in vitro models will be discussed focusing on chitosan- and/or alginate-based systems.This work was developed under the scope of the Structured projects for R&D&I NORTE-01-0145-FEDER-000021 and NORTE-01-0145-FEDER-000023 supported by the Northern Portugal Regional Operational Programme (NORTE 2020), and the Mobilizing Project ValorMar, POCI-01-0247-FEDER-024517, supported by the Operational Programme for Competitiveness and Internationalization (COMPETE 2020), under the Portugal 2020 Partnership Agreement, cofunded by European Regional Development Fund (ERDF). The authors would like also to thank Norte 2020, for financing the PhD scholarship of C.O. “Norte-08-5369-000037” and FCT for the Investigator grant of A.M. (IF/00376/2014)
Silk biomaterials for tendon and tendon-to-bone enthesis tissue engineering
No full textTendons and tendon-to-bone entheses are frequent injury sites among athletes, accounting for up to 50% of all sports-related injuries. Additionally, about 2%–5% of the general population is affected by tendinopathies up to some degree due to overuse, sport-related injuries, and/or degeneration. This situation is likely to worsen in the coming years due to the increasing popularity of sports practice among the middle-aged and elderly population. Unfortunately, the success rate of clinical intervention to treat tendinopathies is far from desirable, with surgical repair failure rates ranging from 20% to 90% in many cases. In this chapter, we review the perspective of tissue engineering to tackle the challenge that represents the successful treatment of injured tendon/enthesis. Furthermore, we look into the potential use of silk biomaterials in tendon and enthesis tissue engineering
Decellularization of porcine heart tissue to obtain extracellular matrix based hydrogels
Get PDFThe use of hydrogels derived from the extracellular matrix (ECM) in tissue engineering applications aims to overcome the conundrum of mimicking the complexity of ECM composition in vitro. In this chapter, we describe a method of decellularization and subsequent formation of an ECM-based hydrogel using porcine heart tissue. These decellularized ECM hydrogels could be used to create semi-interpenetrating networks or as bioinks in bioprinting applications to further enhance the bioactivity and increase the biomimicry degree of the biological cardiac constructs.</p
Orientational behaviors of silk fibroin hydrogels
Get PDFIn this study, a novel shear-induced silk fibroin hydrogel with three-dimensional (3D) anisotropic and oriented gel skeleton/network morphology is presented. Amphipathic anionic and nontoxic sodium surfactin is blended with the silk fibroin to decrease its gelation time during the mechanical shearing process. The fibroin/surfactin blended solutions undergo a facial shearing process to accomplish a solâ gel transition within one hour. The dynamic solâ gel transition kinetic analysis, gel skeleton/network morphology,
and mechanical property measurements are determined in order to visualize the fibroin/surfactin solâ gel transition during the shearing process and its resulting hydrogel. The results demonstrate that there is significant b-sheet assembly from random coil conformations in the fibroin/surfactin blended system during the facile shearing process. The silk fibroin b-sheets further transform into a fibrous large-scale aggregation with orientational and parallel arrangements to the shearing direction. The shear-induced fibroin/
surfactin hydrogel exhibits notable anisotropic and oriented 3D skeleton/network morphology and a significant mechanical compressive strength in proportion to the shearing stress, compared with the control fibroin/surfactin hydrogel undergoing no shearing process. Due to its oriented gel skeleton/network structure and significantly enhanced mechanical properties, the shear-induced fibroin/ surfactin gel may be suitable as a biomaterial in 3D oriented tissue regeneration, including for nerves, the cultivation of bone cells, and the repair of defects in muscle and ligament tissues.The work is supported by National Natural Science Foundation of
China (Grant No. 51373114), PAPD and College Nature Science
Research Project of Jiangsu Province, China (Grant No.
15KJA540001). S. C. Kundu holds ERA Chair Full Professor of
European Commission Programme (RoReCaST) at 3Bs Research
Group, University of Minho, Portugal.info:eu-repo/semantics/publishedVersio
Trends in biomaterials for three dimensional cancer modeling
No full textDuring the last decade, the type of biological assays that are used for extracting information about the efficiency of drugs (including cancer-related compounds) have dramatically changed. The reason is that a large amount of these drugs fail when they are tested in preclinical assays. This is because most pre-clinical drug evaluations rely on simplified in vitro assays based on flat two-dimensional (2D) surfaces. This type of assay poorly correlates with the human disease state. Therein, the cells display artificial phenotypes and perturbed gene expressions. In general, the drugs respond differently than in vivo. Ex vivo (e.g., biopsies)
and in vivo (e.g., animal) models are also employed for drug evaluation. In cancer research, these models display certain advantages over 2D surfaces, such as a greater biological complexity. This makes the drugs to produce native-like responses. However, ex vivo models typically lack perfusion and are not representative of the heterogeneity of the tumor. In contrast, in vivo (animal) models are highly dynamic systems, but they are very costly, lack the human immune system, and are ethically controversial. In addition, regardless of the type of animal model, it is extremely difficult to investigate cellular and physiological interactions on
this type of models. More advanced tumor models are patient-derived xenografts, where a surgically resected tumor sample of a patient is engrafted into an immunodeficient mice. However, these models are extremely expensive and time-consuming, they are associated with ethical concerns, and individual parameters cannot be isolated.This work is financially supported by the European Union Framework Programme for Research and Innovation Horizon 2020 on Forefront Research in 3D Disease Cancer Models as in vitro Screening Technologies (FoReCaST) under grant agreement no. 668983; the Portuguese Foundation for Science and Technology (FCT) under the pro gram CEEC Individual 2017 (CEECIND/00352/2017) to D.C.; and the FCT under the scope of the project Modeling Cancer Metastasis into the Human Microcirculation System using a Multiorgan-on-a-Chip Approach (2MATCH) (02/SAICT/2017 - no 028070) funded by the Programa Operacional Regional do Norte supported by FEDER to D.C. and S.C.K
Figure represents morphology of seeded cells observed by confocal microscope and SEM on sericin matrices (a; c) keratinocytes, (b; d) fibroblasts.
No full text<p>Figure represents morphology of seeded cells observed by confocal microscope and SEM on sericin matrices (a; c) keratinocytes, (b; d) fibroblasts.</p
Multi-sensing Platform Design with a Grating-Based Nanostructure on a Coverslip Substrate
No full textPublisher Copyright: © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.Two different thin film designs with a grating pattern are simulated on a soda lime coverslip, which acts as optical waveguide, with the purpose of generating both a lossy mode resonance (LMR) in transmission and reflection bands. This way both phenomena can be made sensitive to different parameters, leading to a multi-sensing device. The first design consists of a grating patterned in a SnO2 thin film deposited on the coverslip. The performance of the device in both transmission and reflection is numerically studied in air for different values of the grating pitch. Small grating pitches (in the order of the µm) are more suitable for generating the reflection bands while larger values (500 µm or more) are required to produce the LMR, when the reflection bands are no longer visible. Due to the inability to obtain both phenomena with this design, a second design is assessed, where the grating is combined with a section of constant thickness. In this case the desired response is obtained, which opens the path to use this device for multi-sensing applications, measuring several parameters at the same time.Peer reviewe
Percentage degradation in terms of weight loss of sericin crosslinked and uncrosslinked matrices in phosphate buffer saline pH 7.4 solution and in lysozyme solution at 37 °C (n= 3, Mean ±standard deviation, *p< 0.05).
No full text<p>Percentage degradation in terms of weight loss of sericin crosslinked and uncrosslinked matrices in phosphate buffer saline pH 7.4 solution and in lysozyme solution at 37 °C (n= 3, Mean ±standard deviation, *p< 0.05).</p
Engineered 3D Silk‐Based Metastasis Models: Interactions Between Human Breast Adenocarcinoma, Mesenchymal Stem Cells and Osteoblast‐Like Cells
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