Biochemical and physical surface functionalization of polycaprolactone as a key mediator of osteogenic differentiation and vascularized tissue morphogenesis

Tese de Doutoramento em Engenharia de Tecidos, Medicina Regenerativa e Células Estaminais.

Highly functional and biodegradable nanofibrous scaffolds combined with stem cells for bone and cartilage tissue engineering

Among the various possible embodiements of Advanced Therapies and in particular of Tissue Engineering the use of temporary scaffolds to regenerate tissue defects is one of the key issues. The scaffolds should be specifically designed to create environments that promote tissue development and not merely to support the maintenance of communities of cells. To achieve that goal, highly functional scaffolds may combine specific morphologies and surface chemistry with the local release of bioactive agents. Many biomaterials have been proposed to produce scaffolds aiming the regeneration of a wealth of human tissues. We have a particular interest in developing systems based in nanofibrous biodegradable polymers1,2. Those demanding applications require a combination of mechanical properties, processability, cell-friendly surfaces and tunable biodegradability that need to be tailored for the specific application envisioned. Those biomaterials are usually processed by different routes into devices with wide range of morphologies such as biodegradable fibers and meshes, films or particles and adaptable to different biomedical applications. In our approach, we combine the temporary scaffolds populated with therapeutically relevant communities of cells to generate a hybrid implant. For that we have explored different sources of adult and also embryonic stem cells. We are exploring the use of adult MSCs3, namely obtained from the bone marrow for the development autologous-based therapies. We also develop strategies based in extra-embryonic tissues, such as amniotic fluid (AF) and the perivascular region of the umbilical cord4 (Whartonâ s Jelly, WJ). Those tissues offer many advantages over both embryonic and other adult stem cell sourcess. These tissues are frequently discarded at parturition and its extracorporeal nature facilitates tissue donation by the patients. The comparatively large volume of tissue and ease of physical manipulation facilitates the isolation of larger numbers of stem cells. The fetal stem cells appear to have more pronounced immunomodulatory properties than adult MSCs. This allogeneic escape mechanism may be of therapeutic value, because the transplantation of readily available allogeneic human MSCs would be preferable as opposed to the required expansion stage (involving both time and logistic effort) of autologous cells. Topics to be covered: This talk will review our latest developments of nanostructured-based biomaterials and scaffolds in combination with stem cells for bone and cartilage tissue engineering.

Maternal adjustment and maternal attitudes in adolescent and adult pregnant women

Study Objective: This study analyzes differences between adolescent and adult pregnant women and the contribution of maternal age to maternal adjustment and maternal attitudes during pregnancy. Design, Setting, and Participants: A sample of 398 Portuguese pregnant women (111 younger than 19 years) was recruited in a Portuguese Maternity Hospital and completed the Maternal Adjustment and Maternal Attitudes Questionnaire between the 24th and 36th weeks of gestation. Main Outcome Measures: Maternal Adjustment and Maternal Attitudes Questionnaire. Results: Adolescent pregnant women show lower maternal adjustment (poorer body image and worse marital relationship) and poorer maternal attitudes (more negative attitudes to sex) than adult pregnant women. When controlling for socio-demographics, age at pregnancy predicts poorer body image and more negative attitudes to sex, but not a worse marital relationship, more somatic symptoms or negative attitudes to pregnancy and the baby. A worse marital relationship was better predicted by living without the partner, and more somatic symptoms and negative attitudes to pregnancy and the baby was predicted by higher education. Conclusion: Adolescent pregnant women show lower maternal adjustment and poorer maternal attitudes than adult pregnant women according to socio-demographics and unfavorable developmental circumstances.