Hemocompatibility of blood-contacting biomaterials is one of the most important criteria for their successful in vivo applicability. Thus, extensive in vitro analyses according to ISO 10993-4 are required prior to clinical applications. In this review, we summarize essential aspects regarding the evaluation of the hemocompatibility of biomaterials and the required in vitro analyses for determining the blood compatibility. Static, agitated, or shear flow models are used to perform hemocompatibility studies. Before and after the incubation of the test material with fresh human blood, hemolysis, cell counts, and the activation of platelets, leukocytes, coagulation and complement system are analyzed. Furthermore, the surface of biomaterials are evaluated concerning attachment of blood cells, adsorption of proteins, and generation of thrombus and fibrin networks.

When germ‐free cell cultures became a laboratory routine, hopes were high for using this novel technology for treatment of diseases or replacement of cells in patients suffering from injury, inflammation, or cancer or even refreshing cells in the elderly. Today, more than 50 years after the first successful bone marrow transplantation, clinical application of hematopoietic stem cells is a routine procedure, saving the lives of many every day. However, transplanting other than hematopoietic stem and progenitor cells is still limited to a few applications, and it mainly applies to mesenchymal stromal cells (MSCs) isolated from bone marrow. But research progressed and different trials explore the clinical potential of human MSCs isolated from bone marrow but also from other tissues including adipose tissue. Recently, MSCs isolated from bone marrow (bmMSCs) were shown to be a blend of distinct cells and MSCs isolated from different tissues show besides some common features also some significant differences. This includes the expression of distinct antigens on subsets of MSCs, which was utilized recently to define and separate functionally different subsets from bulk MSCs. We therefore briefly discuss differences found in subsets of human bmMSCs and in MSCs isolated from some other sources and touch upon how this could be utilized for cell‐based therapies.

The generation of single-stranded DNA (ssDNA) molecules plays a key role in the SELEX (Systematic Evolution of Ligands by EXponential enrichment) combinatorial chemistry process and numerous molecular biology techniques and applications, such as DNA sequencing, single-nucleotide polymorphism (SNP) analysis, DNA chips, DNA single-strand conformation polymorphism (SSCP) analysis and many other techniques. The purity and yield of ssDNA can affect the success of each application. This study compares the two ssDNA production methods, the strand separation by streptavidin-coated magnetic beads and alkaline denaturation and the lambda exonuclease digestion, in regard to the purity of generated ssDNA and the efficiency. Here, we demonstrate the considerable benefits of ssDNA production by lambda exonuclease digestion for in vitro selection of DNA aptamers. We believe that the generation of ssDNA aptamers using this method will greatly improve the success rate of SELEX experiments concerning the recovery of target-specific aptamers.