Relatório de estágio em farmácia comunitária

Relatório de estágio realizado no âmbito do Mestrado Integrado em Ciências Farmacêuticas, apresentado à Faculdade de Farmácia da Universidade de Coimbr

Aligned hydrogel tubes guide regeneration following spinal cord injury

Directing the organization of cells into a tissue with defined architectures is one use of biomaterials for regenerative medicine. To this end, hydrogels are widely investigated as they have mechanical properties similar to native soft tissues and can be formed in situ to conform to a defect. Herein, we describe the development of porous hydrogel tubes fabricated through a two-step polymerization process with an intermediate microsphere phase that provides macroscale porosity (66.5%) for cell infiltration. These tubes were investigated in a spinal cord injury model, with the tubes assembled to conform to the injury and to provide an orientation that guides axons through the injury. Implanted tubes had good apposition and were integrated with the host tissue due to cell infiltration, with a transient increase in immune cell infiltration at 1 week that resolved by 2 weeks post injury compared to a gelfoam control. The glial scar was significantly reduced relative to control, which enabled robust axon growth along the inner and outer surface of the tubes. Axon density within the hydrogel tubes (1744 axons/mm(2)) was significantly increased more than 3-fold compared to the control (456 axons/mm(2)), with approximately 30% of axons within the tube myelinated. Furthermore, implantation of hydrogel tubes enhanced functional recovery relative to control. This modular assembly of porous tubes to fill a defect and directionally orient tissue growth could be extended beyond spinal cord injury to other tissues, such as vascular or musculoskeletal tissue

Stability of acylcarnitines and free carnitine in dried blood samples: implications for retrospective diagnosis of inborn errors of metabolism and neonatal screening for carnitine transporter deficiency

OBJECTIVE: Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) is increasingly used in newborn screening programs. Acylcarnitine profiles from dried blood spots (DBS) are used to detect fatty acid oxidation disorders, carnitine cycle disorders, and organic acidurias. Stored dried blood is also a valuable source for postmortem investigations to unravel the cause of unexplained death in early childhood. However, diagnostic uncertainties arising from the unknown stability of acylcarnitines and free carnitine during prolonged storage have not yet been studied in a systematic manner. METHODS: Whole blood spiked with acylcarnitines was stored either at -18 degrees C or at room temperature up to 1000 days. At regular time intervals 3.2 mm spots of these samples were extracted with 150 microL of methanol. Free carnitine and acylcarnitines were converted to their corresponding butyl esters and analyzed by ESI-MS/MS. RESULTS: At -18 degrees C acylcarnitines are stable for at least 330 days. If stored for prolonged periods at room temperature (>14 days), acylcarnitines are hydrolyzed to free carnitine and the corresponding fatty acids. The velocity of decay is logarithmic and depends on the chain length of the acylcarnitines. Short-chain acylcarnitines hydrolyze quicker than long-chain acylcarnitines. CONCLUSION: The data indicate that stored filter cards should only be used for retrospective quantitation of acylcarnitines if appropriate correction for sample decay during storage is applied. Free carnitine increases upon storage but can reliably be quantitated under standardized derivatization conditions. Furthermore, carnitine transporter (OCTN2) deficiency can reliably be diagnosed by examining acylcarnitine profiles, which can supplement free carnitine levels as a discriminatory marker