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Nanostructured polymeric coatings based on chitosan and dopamine-modified hyalu...

In a marine environment, specific proteins are secreted by mussels and used as a bioglue to stick to a surface. These mussel proteins present an unusual amino acid 3,4-dihydroxyphenylalanine (known as DOPA). The outstanding adhesive properties of these materials in the sea harsh conditions have been attributed to the presence of the catechol groups present in DOPA. Inspired by the structure and composition of t...

Chitosan membranes containing micro or nano-size bioactive glass particles : ev...

A newfamilyofbiodegradablepolymer/bioactiveglass(BG)compositematerialshas emergedbasedontheavailabilityofnano-sizedbioactiveparticles.Suchnovelbiocompo- sites canhaveenhancedperformance,intermsofmechanicalpropertiesandbioactivity, and theycanbedesignedtobeusedinboneregenerationapproaches. In thiswork,membranesofchitosan(CTS)andchitosanwithbioactiveglass(BG)both micron andnanosizedparticles(CTS/mBG,CTS/nBG,respe...

Biomineralization in chitosan/Bioglass® composite membranes under different dyn...

Fundamental aspects of biomineralization may be important in order to understand and improve calcification onto the surface of biomaterials. The biomineralization process is mainly followed in vitro by assessing the evolution of the apatite layer that is formed upon immersion of the material in Simulated Body Fluid (SBF). In this work we propose an innovative methodology to monitor apatite deposition by looking...

Polymeric layer-by-layer films composed by natural polymers and based on the ad...

Publicado em "Journal of Tissue Engineering and Regenerative Medicine", vol. 7, supp. 1 (2013) ; Some marine species, such as mussels, can strongly attach themselves to rocks in the diffficult conditions of the sea. In fact, marine mussels secrete adhesive proteins that show a high adhesion to both inorganic and organic surfaces in aqueous environments. These proteins have an amino acid designated as 3,4-dihyd...

Cell behaviour in new poly(l-lactic acid) films with crystallinity gradients

We report a new facile method for the development of crystallinity gradients in poly(l-lactic acid) films, based on the gradual dipping of amorphous PLLA samples in a hot bath. Isothermal cold crystallization studies were performed using DSC and optical microscopy in order to find adequate conditions to generate crystallinity gradients in the PLLA films. Cellular response along PLLA samples with graded spheruli...

Chitosan/Poly(ε-caprolactone) blend scaffolds for cartilage repair

Chitosan (CHT)/poly(ε-caprolactone) (PCL) blend 3D fiber-mesh scaffolds were studied as possible support structures for articular cartilage tissue (ACT) repair. Micro-fibers were obtained by wet-spinning of three different polymeric solutions: 100:0 (100CHT), 75:25 (75CHT) and 50:50 (50CHT) wt.% CHT/PCL, using a common solvent solution of 100 vol.% of formic acid. Scanning electron microscopy (SEM) analysis sho...

Designing biomaterials based on biomineralization of bone

In nature, organisms control crystal nucleation and growth using organic interfaces as templates. Scientists, in the last decades, have tried to learn from nature how to design biomimetic biomaterials inspired by the hierarchical complex structure of bone and other natural mineralised tissues or to control the biomineralization process onto biomaterials substrates to promote the osteoconductive properties of im...

Controlling cell behavior through the design of polymer surfaces

pH responsive biomineralization onto chitosan grafted biodegradable substrates

Bioactive composites that enable the formation of an apatite layer onto the surface are important in the development of osteoconductive biomaterials in orthopaedic applications. In this work, the surface of biodegradable and bioactive substrates, composed of poly(L-lactic acid) (PLLA) reinforced with Bioglass , was modified by coupling chitosan to the surface, using plasma activation. The wettability of the mod...

Towards bioinspired superhydrophobic poly(L-lactic acid) surfaces using phase i...

The water repellency and self-cleaning ability of many biological surfaces has inspired many fundamental and practical studies related to the development of synthetic superhydrophobic surfaces. However, the investigation of such substrates made of biodegradable polymers has been scarce. Simple approaches based on a single step, performed at room temperature (and pressure), were implemented to obtain superhydrop...