Percorrer por autor "Ribeiro, Viviana"
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- Biofunctional silk sericin hydrogels: a versatile platform with potential for tissue healing and regenerationPublication . Veiga, Anabela; Ribeiro, Viviana; Ramírez-Jiménez, Rosa Ana; Aguilar, Maria Rosa; Rojo, Luis; Oliveira, Ana L.Discarded silk sericin protein (SS) presents a high yet underexplored potential as a biomaterial for tissue engineering (TE). Despite its biocompatibility, antioxidant activity, and moisture retention properties, its poor stability in aqueous media has limited broader application. In this work, we developed and characterized SS-based hydrogels using tannic acid (TA) and horseradish peroxidase (HRP) crosslinking systems to address these limitations and expand their use in skin TE. Hydrogels were prepared using SS concentrations of 2.5 % and 5 % (w/v) and evaluated for rheological behavior (G′ ranging from 100 to 10,000 Pa), swelling (up to 24 %), retention capacity (stable over 24–30 h), and degradation in proteolytic environments (mass loss ranging from ∼0–11 %, depending on formulation). TA-crosslinked hydrogels showed strong fluid retention and are suitable for high-moisture 3D wound dressings and coating applications. HRP-crosslinked hydrogels demonstrated tunable mechanical properties, shear-thinning behavior, and full recovery post-deformation, making them ideal for use as bioinks in 3D bioprinting and injectable matrices. In vitro assays confirmed cytocompatibility, with viability exceeding 85 %, and successful cell encapsulation and proliferation. Overall, this study presents a versatile SS-based hydrogel platform with potential for various biomedical applications, particularly in skin tissue healing and regeneration.
- Combinatory approach for developing silk fibroin-based scaffolds seeded with human adipose-derived stem cells for cartilage tissue engineering applicationsPublication . Ribeiro, Viviana; Morais, Alain da Silva; Maia, Fátima; Oliveira, Ana; Oliveira, Joaquim; Reis, RuiSeveral processing technologies have been combined to create scaffolds for different tissue engineering (TE) applications. Hydrogels have been extensively used for cartilage TE applications, presenting several structural similarities to the natural extracellular matrix of cartilage tissue environment[1]. From the different biodegradable materials proposed as matrices for cartilage scaffolding[2], silk fibroin (SF) presents high versatility, processability and tailored mechanical properties, which make this protein attractive for the development of innovative matrices for cartilage TE purposes[3]. In a previous study, we proposed fast formed SF hydrogels produced through a horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) crosslinking reaction, taking advantage of the presence of tyrosine groups[4]. In this work, macro-/micro-porous SF scaffolds derived from enzymatically cross- linked SF hydrogels by a HRP/H2O2 complex were produced in combination with salt-leaching and freeze-drying methodologies. The scaffolds morphology, mechanical properties and chemical characterization were assessed by mean of different characterization techniques (SEM, micro-CT, Instron, FTIR and XRD). The scaffolds structural integrity was evaluated by swelling ratio and degradation profile studies. The in vitro ability to support the adhesion, proliferation and differentiation into the chondrogenic lineage was tested using human adipose-derived stem cells (hASCs) cultured over 28 days in basal and chondrogenic conditions. Cell behaviour in the presence of the SF scaffolds was evaluated through different quantitative (GAGs/DNA and RT-PCR) and qualitative (live/dead, SEM, histology and immunocytochemistry) assays. The in vivo biocompatibility of the SF-based scaffolds was also assessed by subcutaneous implantation in mice for 2 and 4 weeks and analysed by means of hematoxylin & eosin (H&E) staining and immunohistochemical analysis of CD31 angiogenic marker. The results showed highly porous and interconnected SF structures that allowed cell adhesion and infiltration into the scaffolds. In vitro cell viability and proliferation were also observed over the 28 days of culturing in basal conditions and a significant increase of GAGs content was detected on constructs cultured in chondrogenic differentiation medium. In vivo results showed that the implanted scaffolds allowed tissue ingrowth’s and blood vessels formation/infiltration. The obtained results demonstrated that the innovative approach of combining enzymatically cross-linked SF hydrogels with the salt- leaching and freeze-drying methodologies allowed to produce more versatile scaffold architectures with appropriate mechanical properties and large swelling ability. The positive influence over in vitro chondrogenic differentiation and in vivo response, revealed by the new tissue formation and angiogenesis within the porous scaffolds, validates the proposed macro-/micro-porous SF scaffolds for being used in cartilage TE applications. Moreover, the versatility of these combinatory approach can allow for further applications in other musculoskeletal TE strategies.
- Combinatory approach for developing silk fibroin-based scaffolds with hierarchical porosity and enhanced performance for cartilage tissue engineering applicationsPublication . Ribeiro, Viviana; Yan, Le-Ping; Oliveira, Ana L.; Oliveira, Joaquim M.; Reis, Rui L.Introduction: The combination of several processing technologies can open the possibility for producing scaffolds with superior performance for tissue engineering (TE) applications. Hydrogels are structurally similar to the natural extracellular matrix microenvironment presenting high elasticity and resistance to compression forces. They have been extensively used in biomedical devices fabrication and for TE applications, including for cartilage defects repair[1]. Recently, it was found that proteins like silk fibroin (SF), presenting tyrosine groups can be used to prepare fast formed hydrogels with controlled gelation properties, via an enzyme-mediated cross-linking reaction using horseradish peroxidase (HRP) and hydrogen peroxide (H2O2)[2],[3]. Moreover, the high versatility, processability and tailored mechanical properties of SF, make this natural polymer attractive for the development of innovative scaffolding strategies for cartilage TE applications[4],[5]. Materials and Methods: The present work proposes a novel route for developing SF-based scaffolds derived from high-concentrated SF (16wt%) enzymatically cross-linked by a HRP/H2O2 complex. The combination of salt-leaching and freeze-drying methodologies was used to prepare macro/microporous SF scaffolds with an interconnected structure and specific features regarding biodegradation and mechanical properties (Fig. 1a). The scaffolds morphology and porosity were analyzed by SEM and micro-CT. The mechanical properties (Instron) and protein conformation (FTIR, XRD) were also assessed. In order to evaluate the scaffolds structural integrity, swelling ratio and degradation profile studies were performed for a period of 30 day. This work also aims to evaluate the in vitro chondrogenic differentiation response by culturing human adipose derived stem cells (hASCs) over 21 days in basal and chondrogenic conditions. Cell behaviour in the presence of the macro/microporous structures will be evaluated through different quantitative (Live/Dead, DNA, GAGs, RT PCR) and qualitative (SEM, histology, immunocytochemistry) assays. Results and Discussion: The macro/microporous SF scaffolds showed high porosity and interconnectivity with the trabecular structures evenly distributed (Fig. 1b,c). A dramatic decrease of compressive modulus was observed for samples in hydrated state. Chemical analysis revealed that SF scaffolds displayed the characteristic peaks for β-sheet conformation. Swelling ratio data demonstrated a large swelling capacity, maintaining their structural integrity for 30 days. As expected, when immersed in protease XIV the degradation rate of SF scaffolds increased. Based on the promising morphology and physicochemical properties of the developed SF scaffolds, in vitro chondrogenic differentiation studies with hASCs are envisioned in order to validate their performance for cartilage regeneration applications.
- Decellularized small intestine for burn wound treatment: a tissue engineering paradigm shift?Publication . Silva, Inês V.; Rosadas, Marta; Rodrigues, Ilda; Sousa, Clara; Ribeiro, Viviana; Costa, Raquel; Moroni, Lorenzo; Oliveira, Ana L.Introduction: Burn injuries are a significant global health issue, causing approximately 11 million injuries and 180,000 fatalities each year (1). Beyond physical trauma, burn injuries lead to complications such as infections and sepsis. Burn scars can also diminish quality of life by affecting joint mobility and daily activities (2,3). Conventional dressings and autografts have limitations, necessitating novel treatment strategies (4). Decellularized xenografts, particularly from porcine small intestine (SI), offer a promising alternative due to their content of growth factors and structural proteins essential for wound healing (5,6). Preserving these bioactive molecules while ensuring cost-effectiveness requires carefully designed decellularization processes. This study investigates a new decellularization protocol aimed at creating a safe and highly preserved extracellular matrix (ECM) from porcine SI for optimal functional wound dressing. Conclusion: Our results indicate that the protocol implemented effectively preserves essential ECM components and structure while removing cellular contaminants. The material demonstrates anisotropic preserved mechanical properties, adequate swelling capacity, and WTVR similar to skin. The treated samples present biocompatibility, as they do not hinder human fibroblast metabolic activity. This innovative strategy presents a promising approach to produce preserved ECM that could be further process to become a solution for wound healing and tissue regeneration, particularly in challenging cases like burns. Future research will focus on enhancing its antibacterial and anti-inflammatory properties to further improve its efficacy as a dressing for challenging wounds.
- Exploring new biobased material sources as platforms to advance skin wound healing and regenerationPublication . Ribeiro, Viviana; Bernardes, Beatriz G.; Duarte, Marta; Rosadas, Marta; Sousa, Teresa; Sousa, Alda; Serra, Julia; García-González, Carlos; Oliveira, Ana L.Chronic wounds are one of the major therapeutic and healthcare challenges affecting the population globally. One of the research interests of the Biomaterials and Biomedical Technology Lab (BBT Lab) is to explore the potential of biobased material platforms to advance skin wound healing and regeneration solutions. From the use of natural based biopolymers such as silk fibroin (SF) or sulfated exopolysaccharides (EPS), to the processing of more complex matrices such as the extracellular matrices, the group has been collaborating with some strategic partners in IBEROS+ to process, functionalize and characterize the materials for their physicochemical properties, structural adaptability, biocompatibility and bioactivity. SF microparticulate aerogels loaded with adenosine have been developed via supercritical fluid technology in collaboration with the University of Santiago de Compostela. These particles exhibit a high porosity, biocompatibility, and positive interactions with skin cells towards regeneration, highlighting their promise in wound healing. A new Exopolysaccharide (EPS) produced by Porphyridium cruentum microalgae was developed as a novel biomaterial platform, offering bioactive properties, high molecular weight, thermal stability, and cytocompatibility for complex wound healing. An extensive characterization is ongoing, with contribution of the University of Vigo. For extensive burn wounds, where autologous grafts are impractical, skin xenografts may provide a viable alternative, mostly if depleted from its immunogenic load. To achieve this, our group has developed and optimized methods for obtaining highly-preserved animal- origin decellularized tissues for human skin healing and regeneration. An important example is the valorization of rabbit skin, a valuable agro-food by-product that exceeds 5000 skins/day only in Europe. Our group has recently developed decellularized rabbit dermal matrices with preserved microarchitecture and human-like biochemical properties and expects to continue further developments in collaboration with the IBEROS+ consortium.
- Finely tuned fiber-based porous structures for bone tissue engineering applicationsPublication . Ribeiro, Viviana; Silva-Correia, Joana; Morais, Alain; Correlo, Vitor M.; Marques, Alexandra P.; Ribeiro, Ana; Silva, Carla; Durães, Nelson; Bonifácio, Graça; Sousa, Rui A.; Oliveira, Joaquim M.; Oliveira, Ana L.; Reis, Rui L.
- Silk sericin hydrogels as a promising sustainable platform for skin tissue engineeringPublication . Veiga, Anabela; Baptista-Silva, Sara; Foster, Olivia; Costa, Raquel; Ribeiro, Viviana; Castro, Filipa; Rocha, Fernando; Kaplan, David L.
- Textile-based silk scaffolds for bone tissue engineering applicationsPublication . Ribeiro, Viviana; Morais, Alain; Correlo, Vitor M.; Marques, Alexandra P.; Ribeiro, Ana; Silva, Carla; Durães, Nuno; Bonifácio, Graça; Sousa, Rui; Oliveira, Joaquim M.; Reis, Rui L.; Oliveira, Ana L.INTRODUCTION: Scaffolds developed for bone tissue engineering (TE) need to facilitate and promote cell adhesion, proliferation and neo-tissue formation. They must possess specific properties to allow the new tissue to integrate with the material, without inducing any inflammatory response. The intra-architectural scaffold geometry, porosity, scaffold material and surface area play important roles in this process . Several polymeric systems (natural and/or synthetic) and processing methods and have been proposed to develop the “ideal” scaffold for bone TE. However, so far the proposed strategies do not fulfil all the requirements for effective bone regeneration. Textile-based technologies constitute an innovative alternative for the production of 3D structures for bone TE applications, offering a superior control over scaffolds’ design, manufacturing and reproducibility. Silk fibroin (SF) derived from silkworm Bombyx mori has already proved to be a good biomaterial for bone TE applications. SF-based structures offer impressive mechanical properties, biodegradability, biocompatibility and stability, which meets the basic requirements for the design of structures for bone regeneration applications. EXPERIMENTAL METHODS: In this work we describe for the first time the processing of natural silk yarns into 3D scaffolds, combining standard knitting fabrics spaced by a monofilament of polyethylene terephthalate (PET). A comparative study is established using a stable polymeric system made entirely of PET. The obtained knitted spacer constructs were described in terms of morphology and mechanical properties. An in vitro biological assay was performed to evaluate the potential of the developed structures to support human Adipose- derived Stem Cells (hASCs) adhesion, proliferation and osteogenic differentiation. Cells were cultured over 28 days in standard basal and osteogenic conditions and evaluated through different quantitative (DNA, ALP, Calcium, RT-PCR) and qualitative (SEM, Alizarin Red, immunocytochemistry) assays. The in vivo biocompatibility of the textile materials was assessed by subcutaneous implantation in mice model. After 2 and 4weeks of implantation the explants were collected and the obtained slides were stained with hematoxylin and eosin (H&E). RESULTS AND DISCUSSION: The cross-sections of the developed spacer textile constructs reveal a significant increase of the scaffolds three-dimensionality induced by the PET monofilament (Figure 1a). The hASCs seeded onto the spacer textile scaffolds were able to attach, spread, proliferate and differentiate, both in osteogenic and basal conditions (Figure 1b). Great evidences of ECM mineralization were observed, also penetrating and colonizing the PET monofilament (Figure 1a). The preliminary in vivo results revealed that the implanted scaffolds allowed tissue ingrowth, without inducing any acute inflammatory reaction (Figure 1c). CONCLUSION: In this study, innovative 3D biotextile scaffolds able to support cell adhesion, proliferation and osteogenesis were successfully developed. Furthermore, these scaffolds allowed the new tissue formation and integration within the material, when subcutaneously implanted in mice. Thus, the proposed textile-based scaffolds can be promising candidates for bone TE applications such as the craniomaxilofacial complex.