3Bs Research Group Biomaterials

Caldas, Portugal

3Bs Research Group Biomaterials

Caldas, Portugal
Time filter
Source Type

Carvalho A.F.,3Bs Research Group Biomaterials | Gasperini L.,3Bs Research Group Biomaterials | Ribeiro R.S.,3Bs Research Group Biomaterials | Marques A.P.,3Bs Research Group Biomaterials | Reis R.L.,3Bs Research Group Biomaterials
Journal of Tissue Engineering and Regenerative Medicine | Year: 2017

Design of tissue engineering strategies deals with the need to balance both biomaterials characteristics and techniques specificities, often resulting in cell-compromising processing conditions. One important factor often disregarded is the osmotic pressure to which cells are exposed. An in-house microfluidic system was used to prove that addition of an osmotic regulator significantly benefits the generation of viable cell-laden hydrogels under harsh processing conditions. Human adipose-derived stem cells were resuspended in 1.5% alginate and 1% gellan gum (GG; w/v) solutions containing different concentrations (0.12 m, 0.25 m and 1.5 m) of sucrose as osmotic regulator. GG (in water) and alginate (in water or phosphate-buffered saline) solutions were used to vary the conditions under which cells were kept prior processing. Independently of the polymer, addition of sucrose did not affect the processing conditions or the viscosity of the solutions, except at 1.5 m. The obtained results clearly demonstrate that inclusion of 0.25 m sucrose during processing of the cell-laden hydrogels allowed to keep cell viability around 80%, in opposition to the 20% observed in its absence, both for GG and alginate-derived hydrogels prepared in water. Impressively, the level of cell viability observed with the inclusion of 0.25 m sucrose, 76% for GG and 86% for alginate, was similar to that obtained with the standard alginate solution prepared in phosphate-buffered saline (82%). The beneficial effect of sucrose was observed within the first 5 min of processing and was maintained for prolonged experimental setups with viability values above 50%, even after a 2-h time-frame and independently of the material. © 2017 John Wiley & Sons, Ltd.

Sousa C.,University of Minho | Rodrigues D.,University of Minho | Oliveira R.,University of Minho | Song W.,University of Minho | And 6 more authors.
AMB Express | Year: 2011

Hydrophobicity is a very important surface property and there is a growing interest in the production and characterization of superhydrophobic surfaces. Accordingly, it was recently shown how to obtain a superhydrophobic surface using a simple and cost-effective method on a polymer named poly(L-lactic acid) (PLLA). To evaluate the ability of such material as a substrate for bacterial colonization, this work assessed the capability of different bacteria to colonize a biomimetic rough superhydrophobic (SH) PLLA surface and also a smooth hydrophobic (H) one. The interaction between these surfaces and bacteria with different morphologies and cell walls was studied using one strain of Staphylococcus aureus and one of Pseudomonas aeruginosa. Results showed that both bacterial strains colonized the surfaces tested, although significantly higher numbers of S. aureus cells were found on SH surfaces comparing to H ones. Moreover, scanning electron microscopy images showed an extracellular matrix produced by P. aeruginosa on SH PLLA surfaces, indicating that this bacterium is able to form a biofilm on such substratum. Bacterial removal through lotus leaf effect was also tested, being more efficient on H coupons than on SH PLLA ones. Overall, the results showed that SH PLLA surfaces can be used as a substrate for bacterial colonization and, thus, have an exceptional potential for biotechnology applications. © 2011 Sousa et al; licensee Springer.

Oliveira S.M.,3Bs Research Group Biomaterials | Oliveira S.M.,Icvs 3Bs Pt Government Associ Laboratory | Silva T.H.,3Bs Research Group Biomaterials | Silva T.H.,Icvs 3Bs Pt Government Associ Laboratory | And 4 more authors.
Journal of Materials Chemistry B | Year: 2013

The understanding of both cell-extracellular matrix (ECM) and cell-material interactions is crucial for the success of implantable biomaterials including tissue engineering devices. ECM is rich in sulfated and aminated glycosaminoglycans and proteoglycans. The development of synthetic models containing those chemical groups is thus of major interest. Thin coatings of polysaccharides with controlled sulfur and nitrogen contents were developed by layer-by-layer assembly. In particular, the multilayers were prepared by assembling chitosan with κ-, ι- and λ-carrageenan (increasing sulfur content). The nanostructured multilayers were characterized by quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), scanning electron microscopy (SEM), water contact angle, X-ray photoelectron spectroscopy (XPS) and used as models to study the effect of the sulfate groups over the behavior of osteoblast-like cells. The biomimetic coatings increased the alkaline phosphatase (ALP) activity and proliferation compared with unmodified polycaprolactone surfaces. Biomineralization increase with the presence of the coatings is significantly higher on ι-carrageenan coatings, suggesting that the sulfate groups may interact positively with molecules involved in the osteoblastic activity as it occurs in the natural ECM. The developed nanocoatings can constitute an interesting model to understand the biological influence of the sulfate and amine groups existing on the surface of biomaterials. This journal is © The Royal Society of Chemistry 2013.

Song W.,3Bs Research Group Biomaterials | Song W.,IBB Institute for Biotechnology And Bioengineering | Gaware V.S.,University of Iceland | Runarsson O.V.,University of Iceland | And 3 more authors.
Carbohydrate Polymers | Year: 2010

Chitosan has been greatly applied in the fields of biomedicine, biomembranes and food/nutrition because of its nontoxic and biocompatible properties. However, water solubility of chitosan at pH < 5 strongly limits the use of chitosan-based films when pH stability and low water uptake are required in many actual applications. In this work, silyl chitosan, 3,6-O-di-tertbutyldimethyl silyl chitosan, a chitosan derivative, was synthesized and used to prepare extreme water-repellent films in the whole pH range of 1-14 using a phase separation method that exhibit topography with a three-level hierarchical roughness organization. The polymer also allows posterior chemical modification specifically through the amine group, permitting to control the surface chemistry and wettability. This work not only improve the stabilization of chitosan-based films but also demonstrates the possibility of manufacturing polysaccharide-based superhydrophobic surfaces with potential to be used in anti-bacterial substrates, tissue engineering, food industry and other biomedical applications. © 2010 Elsevier Ltd. All rights reserved.

Grech J.M.R.,3Bs Research Group Biomaterials | Grech J.M.R.,IBB Institute for Biotechnology And Bioengineering | Mano J.F.,3Bs Research Group Biomaterials | Mano J.F.,IBB Institute for Biotechnology And Bioengineering | And 2 more authors.
Journal of Materials Science: Materials in Medicine | Year: 2010

Chitosan (Ch) microspheres have been developed by precipitation method, cross-linked with glutaraldehyde and used as a template for layer-by-layer (LBL) deposition of two natural polyelectrolytes. Using a LBL methodology, Ch microspheres were alternately coated with hyaluronic acid (HA) and Ch under mild conditions. The roughness of the Ch-based crosslinked microspheres was characterized by atomic force microscopy (AFM). Morphological characterization was performed by environmental scanning electron microscopy (ESEM), scanning electron microscopy (SEM) and stereolight microscopy. The swelling behaviour of the microspheres demonstrated that the ones with more bilayers presented the highest water uptake and the uncoated cross-linked Ch microspheres showed the lowest uptake capability. Microspheres presented spherical shape with sizes ranging from 510 to 840 μm. ESEM demonstrated that a rougher surface with voids is formed in multilayered microspheres caused by the irregular stacking of the layers. A short term mechanical stability assay was also performed, showing that the LBL procedure with more than five bilayers of HA/Ch over Ch cross-linked microspheres provide higher mechanical stability. © 2010 Springer Science+Business Media, LLC.

Song W.,3Bs Research Group Biomaterials | Song W.,IBB Institute for Biotechnology And Bioengineering | Lima A.C.,3Bs Research Group Biomaterials | Lima A.C.,IBB Institute for Biotechnology And Bioengineering | And 2 more authors.
Soft Matter | Year: 2010

Inspired by the rolling of water drops over the lotus leaf, we propose a new biomimetic fabrication process for hydrogel and polymeric spheres over a superhydrophobic substrate. This method may be potentially applied in tissue engineering or as support for cell expansion, cell encapsulation and as spherical structures for controlled release of molecule. © 2010 The Royal Society of Chemistry.

Santos J.R.,3Bs Research Group Biomaterials | Santos J.R.,IBB Institute for Biotechnology And Bioengineering | Alves N.M.,3Bs Research Group Biomaterials | Alves N.M.,IBB Institute for Biotechnology And Bioengineering | And 2 more authors.
Journal of Bioactive and Compatible Polymers | Year: 2010

New pH and temperature sensitive semi-interpenetrated polymer networks (semi-IPNs) were developed by combining cross-linked PNIPAAm with hyaluronic acid (HA). At pH 7.4, the PNIPAAm/HA semi-IPN hydrogels had significantly greater and faster swelling at 25°C and a more complete deswelling at 37°C than PNIPAAm hydrogels. The temperature-dependent reversibility behavior was analyzed for biomaterial applications. Gentamicin was incorporated as a model drug, and the release profile from the hydrogels was followed under physiological conditions. The presence of HA, even in small quantities, allowed a more complete release of the gentamicin from the hydrogel. The PNIPAAm/HA semi-IPN hydrogels respond to both changes in temperature and pH making it suitable as a delivery system for therapeutics.

Correia C.R.,3Bs Research Group Biomaterials | Correia C.R.,ICVS 3Bs PT Government Associate Laboratory | Sher P.,3Bs Research Group Biomaterials | Sher P.,ICVS 3Bs PT Government Associate Laboratory | And 4 more authors.
Soft Matter | Year: 2013

We report the development of liquified multilayer hierarchical capsules capable of providing cell adhesion sites to the encapsulated cells. The proof of principle is demonstrated with the example of a chitosan-alginate shell via layer-by-layer assembly, encapsulating cells adhered to the functionalized surface of poly(l-lactic acid) microparticles. This journal is © 2013 The Royal Society of Chemistry.

Gil S.,3Bs Research Group Biomaterials | Mano J.F.,3Bs Research Group Biomaterials
Biomaterials Science | Year: 2014

Magnetic nanoparticles (MNPs) have been increasingly used in tissue engineering and regenerative medicine. These particles have been mainly employed as elements directly incorporated into cells or interacting with cell membranes; however, MNPs are now being combined with biomaterials to create other functionalities of the structural framework used to support cells, namely for controlling cellular responses and for enhancing drug delivery and release. This mini-review summarizes and highlights the latest developments and applications of polymeric/ceramic biomimetic scaffolds and hydrogels that contain MNPs for such purposes, also addressing future perspectives for the use of these magnetic composite biomaterials in biomedicine. This journal is © the Partner Organisations 2014.

PubMed | 3Bs Research Group Biomaterials
Type: | Journal: Acta biomaterialia | Year: 2016

Human platelet lysate (PL) is a cost-effective and human source of autologous multiple and potent pro-angiogenic factors, such as vascular endothelial growth factor A (VEGF A), fibroblast growth factor b (FGF b) and angiopoietin-1. Nanocoatings previously characterized were prepared by layer-by-layer assembling incorporating PL with marine-origin polysaccharides and were shown to activate human umbilical vein endothelial cells (HUVECs). Within 20 h of incubation, the more sulfated coatings induced the HUVECS to the form tube-like structures accompanied by an increased expression of angiogenic-associated genes, such as angiopoietin-1 and VEGF A. This may be a cost-effective approach to modify 2D/3D constructs to instruct angiogenic cells towards the formation of neo-vascularization, driven by multiple and synergistic stimulations from the PL combined with sulfated polysaccharides.The presence, or fast induction, of a stable and mature vasculature inside 3D constructs is crucial for new tissue formation and its viability. This has been one of the major tissue engineering challenges, limiting the dimensions of efficient tissue constructs. Many approaches based on cells, growth factors, 3D bioprinting and channel incorporation have been proposed. Herein, we explored a versatile technique, layer-by-layer assembling in combination with platelet lysate (PL), that is a cost-effective source of many potent pro-angiogenic proteins and growth factors. Results suggest that the combination of PL with sulfated polyelectrolytes might be used to introduce interfaces onto 2D/3D constructs with potential to induce the formation of cell-based tubular structures.

Loading 3Bs Research Group Biomaterials collaborators
Loading 3Bs Research Group Biomaterials collaborators