Biomimetic supramolecular designs for the controlled release of growth factors in bone regeneration

The extracellular matrix (ECM) of tissues is an assembly of insoluble macromolecules that specifically interact with soluble bioactive molecules and regulate their distribution and availability to cells. Recapitulating this ability has been an important target in controlled growth factor delivery strategies for tissue regeneration and requires the design of multifunctional carriers. This review describes the integration of supramolecular interactions on the design of delivery strategies that encompass self-assembling and engineered affinity components to construct advanced biomimetic carriers for growth factor delivery. Several glycan- and peptide-based self-assemblies reported in the literature are highlighted and commented upon. These examples demonstrate how molecular design and chemistry are successfully employed to create versatile multifunctional molecules which self-assemble/disassemble in a precisely predicted manner, thus controlling compartmentalization, transport and delivery. Finally, we discuss whether recent advances in the design and preparation of supramolecular delivery systems have been sufficient to drive real translation towards a clinical impact. 

PHB-HV 3D Scaffold supports osteoblast growth

Bone tissue engineering requires a biocompatible scaffold that supports cell growth and enhances the native repair process. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV) is a biodegradable 3D scaffold with 88.1 â 0.3% porosity and pore size of 163.5 â 0.1 mm. Previous studies demonstrated the potential of PHB-HV as a scaffold in spinal cord repair. The aim of this study was to evaluate PHB-HV as a scaffold for bone regeneration by assessing the cytocompatability of this scaffold.

A vegetação na envolvente exterior dos edifícios: impactos, condicionantes e estratégias de intervenção ecoeficientes

Dissertação de mestrado integrado em Arquitectura

Chitosan-based scaffolds for tissue regeneration: preparation and microstructure characterization

Scaffolds are porous three-dimensional supports, designed to mimic the extracellular environment and remain temporarily integrated into the host tissue while stimulating, at the molecular level, specific cellular responses to each type of body tissues. The major goal of the research work entertained herein was to study the microstructure of scaffolds made from chitosan (Ch), blends of chitosan and sodium alginate (Ch/NaAlg), blends of chitosan, sodium alginate and calcium chloride (Ch/NaAlg/CaCl2) and blends of chitosan, sodium alginate and hydroxyapatite (Ch/NaAlg/HA). Scaffolds possessing ideal physicochemical properties facilitate cell proliferation and greatly increase the rate of recovery of a damaged organ tissue. Using CT three-dimensional images of the scaffolds, it was observed that all scaffolds had a porosity in the range 64%-92%, a radius of maximum pore occurrence in the range 95m-260m and a permeability in the range 1×10-10-18×10-10 m2. From the results obtained, the scaffolds based on Ch, Ch/NaAlg and Ch/NaAlg/CaCl2 would be most appropriate both for the growth of osteoid and for bone tissue regeneration, while the scaffold made with a blend of Ch/NaAlg/HA, by possessing larger pores size, might be used as a support for fibrovascular tissue.

Looking for mechanisms regulating lung growth in CDH: rat and human studies

Tese de Doutoramento em Ciências da Saúde

Hydrogels and cell based therapies in spinal cord injury regeneration

Spinal cord injury (SCI) is a central nervous system- (CNS-) related disorder for which there is yet no successful treatment. Within the past several years, cell-based therapies have been explored for SCI repair, including the use of pluripotent human stem cells, and a number of adult-derived stem and mature cells such as mesenchymal stem cells, olfactory ensheathing cells, and Schwann cells. Although promising, cell transplantation is often overturned by the poor cell survival in the treatment of spinal cord injuries. Alternatively, the therapeutic role of different cells has been used in tissue engineering approaches by engrafting cells with biomaterials. The latter have the advantages of physically mimicking the CNS tissue, while promoting a more permissive environment for cell survival, growth, and differentiation. The roles of both cell- and biomaterial-based therapies as single therapeutic approaches for SCI repair will be discussed in this review. Moreover, as the multifactorial inhibitory environment of a SCI suggests that combinatorial approaches would be more effective, the importance of using biomaterials as cell carriers will be herein highlighted, as well as the recent advances and achievements of these promising tools for neural tissue regeneration.