Clinical islet transplantation is a promising treatment for type 1 diabetes. It involves the transplantation of pancreatic islets, isolated from a donor, into the portal vein of a recipient in order to replace his/her dysfunctional islets. Though promising, islet implantation into the liver is greatly hindered by numerous problems, including mechanical stresses, inflammatory responses, exposure to high drug and toxin loads, as well as irretrievability. In order to address these concerns, investigation into alternative implant sites, such as the subcutaneous site, has intensified. Transplantation of islets within these extrahepatic sites is commonly met with three primary obstacles: 1) inadequate spatial distribution of the cells; 2) oxygen deficiency in the local environment; and 3) insufficient vascularization within and around the implant. Thus, the objective of this proposal is to engineer a superior bioartificial pancreas, a device combining novel biomaterials and insulin-secreting cells, by focusing on these critical issues, specifically how to best reduce islet aggregation, as well as increase oxygen delivery, both in the short term and long term. A highly macroporous silicone scaffold will be engineered to distribute the islets three-dimensionally, while not imparting diffusion resistances commonly encountered in microporous materials. Macroporous scaffolds will also permit vascular in-growth. In order to sustain oxygen levels at the moment of device implantation, a novel, oxygen generating disk, which relies on the decomposition of calcium peroxide, will be developed and incorporated alongside the scaffold to deliver short-term supplemental oxygen. Therefore, it is postulated that these bioactive scaffolds, which interact with islets on a spatial, chemical, and biological level, will improve the viability as well as the function of islets, both in vitro and in vivo, as compared to naked islets under extrahepatic conditions.

During the construction of the new urban area in the north-eastern part of Stockholm, Stockholm Royal Seaport, groundwater with extremely elevated levels of the carcinogenic aromatic hydrocarbon benzene was discovered in the area Hjorthagen. Such a contamination can be remediated in-situ by the use of chemical oxidation and biodegradation. Due to the fact that many factors such as contaminant composition, groundwater characteristics and temperature vary between sites, smaller bench scale studies are usually conducted before the full scale remediation on site. Little published research exists on the ability of these remediation techniques in areas with lower groundwater temperature such as Stockholm, why the need of a bench-scale study in this case is even larger. The objective of this master thesis is to, out of three investigated remediation agents, find the most suitable one for remediation of the benzene-contaminated groundwater in Hjorthagen. This was made in the form of a bench-scale study and the techniques studied were chemical oxidation, for which the two agents hydrogen peroxide (uncatalyzed and catalyzed in the form of Fenton’s reagent) and persulfate (activated with iron (II)) were used, and biological degradation by the use of a calcium peroxide-based compound. The study showed that the benzene-contaminated groundwater was best remediated with Fenton’s reagent, which was able to degrade the benzene with great success.