Nephila edulis-breeding and care under laboratory conditions.

Due to fascinating mechanical and biological characteristics spider silk is of great interest in many research fields. Among the orb-weavers Nephila edulis is one of the species used as source for natural spider silk in laboratories. Under appropriate conditions, animals can be kept and bred easily. This manuscript gives information about the spiders' natural habitat, behavior, and breeding and compares them with the established methods and conditions within a research laboratory. Keeping conditions and methods of rearing are described in detail. Within a keeping facility with reliable supply of food, cannibalism rate is significantly reduced and spiders mate all year long. Cohabitants of the genus Steatoda are routinely found in laboratory keeping. While these small spiders do not pose a threat to Nephila edulis, cellar spiders (family Pholcidae) have to be extracted as they have been observed hunting for Nephila spiders.

Influence of direct or indirect contact for the cytotoxicity and blood compatibility of spider silk.

Spider silk became one of the most-researched biomaterials in the last years due to its unique mechanical strength and most favourable chemical composition for tissue engineering purposes. However, standardized analysis of cytocompatibility is missing. Therefore, the aim of this study was to investigate hemolysis, cytotoxicity of native spider silk as well as influences on the cell culture medium. Changes of cell culture medium composition, osmolarity as well as glucose and lactate content were determined via ELISA measurement. Possible hemolysis and cytotoxicity in vitro of spider silk were performed via measurement of hemoglobin release of human red blood cells or relative metabolic activity of L929 fibroblasts, respectively, according to international standard procedures. In ELISA measurement, no significant changes in medium composition could be found in this study. Spider silk was not hemolytic in direct and indirect testing. However, a borderline cytotoxicity according to definitions was found in indirect cytotoxicity testing. Nevertheless, in direct cytotoxicity testing, relative metabolic activity measurement revealed that spider silk is not cytotoxic under these conditions. This is the first study to conduct standardized tests regarding cytotoxicity and hemolysis of native spider silk, which might be considered inert in cell culture. As neither hemolysis nor cytotoxicity was found in direct contact in standardized procedures, safety in biomedical applications may be assumed. The indirect cytotoxicity seems to play a minor role in vivo. However, a borderline toxicity was revealed, suggesting potential leachables not yet identified. Displays one of the weaving frames used in this study after seeding with the single drop technique described herein.

[Regenerative therapy approaches in plastic surgery]. / Regenerative Therapieansätze in der plastischen Chirurgie.

BACKGROUND: The regeneration of tissue lost due to trauma or disease is considered as being ideal for reconstruction with respect to repair in which a donor defect arises in a different part of the body. Through a better understanding of the cellular and molecular mechanisms of healing, possibilities for regenerative therapies have been developed in recent years. OBJECTIVES: To give an exemplary representation of current regenerative therapy approaches and their effect and clinical application. MATERIAL AND METHODS: The PubMed database was searched for different regenerative approaches in plastic surgery and various methods are presented in this article. RESULTS: Cell-based approaches, in which autologous mesenchymal stem cells from adipose tissue are preferably used, led to excellent healing results with minimal donor site morbidity. Likewise, growth factor-based approaches or the use of platelet-rich plasma achieve very good results in the field of wound and bone healing. DISCUSSION: By using different cells or molecules and thus taking advantage of biological mechanisms, the regenerative capabilities of adult organisms could be improved. Many methods have already been implemented in clinical practice, not only in reconstructive but also in aesthetic surgery. However, the success should not conceal the potential risk that is inherent in both cell and growth factor-based approaches. Until long-term experiences of such therapies have been acquired, they should be used cautiously.

[The role of erythropoietin in improvement of wound healing]. / Die Rolle von Erythropoietin bei der Verbesserung der Wundheilung.

Pleiotropic substances are characterized by their versatile and complex range of actions which makes them potential new active agents for the therapy of wounds. Besides its known effect to increase red blood cell production, the glycoprotein hormone erythropoietin (EPO) has been found to demonstrate a tissue protective effect in several other organs. The administration of EPO during skin wound healing is most likely essentially based on its cytopotective, proangiogenic, antiapoptotic and antiinflammatory effects. Herein EPO stimulates a coordinated interaction of different types of cells at a low or only a single dose. This review article aims to present the advantages and disadvantages of EPO administration in different experimental models to study the healing and regeneration processes of the skin and discusses possible clinical applications.

[Stem cells from fatty tissue : A new resource for regenerative medicine?]. / Stammzellen aus dem Fettgewebe : Eine neue Ressource für die regenerative Medizin?

While stem cells derived from the bone marrow are well-known in clinical medicine, fatty tissue as a source of mesenchymal stem cells is still the subject of recent research. However, adipose-derived stem cells (ASC) are not only harvested less invasively, i.e. via minimally invasive liposuction, but also yield higher numbers of multipotent stem cells.Due to cell-cell interactions and also because of the very favorable secretion profile of growth factors and cytokines ASCs displayed an extraordinary regenerative potential in recent preclinical and clinical applications and achieved a significantly better healing in ischemic muscle, heart, and brain insults and in impaired wound healing. ASCs enhanced regeneration in skeletal tissues such as cartilage or bone. They also revealed immunomodulatory effects and improved the clinical status in immunological diseases.In conclusion ASCs are comparable to bone marrow-derived stem cells concerning possible applications in clinical medicine.