Publications by authors named "Thomas Niemietz"

Cell-based tissue engineering is a promising approach for treating cartilage lesions, but available strategies still provide a distinct composition of the extracellular matrix and an inferior mechanical property compared to native cartilage. To achieve fully functional tissue replacement more rationally designed biomaterials may be needed, introducing bioactive molecules which modulate cell behavior and guide tissue regeneration. This study aimed at exploring the impact of cell-instructive, adhesion-binding (GCWGGRGDSP called RGD) and collagen-binding (CKLER/CWYRGRL) peptides, incorporated in a tunable, matrixmetalloprotease (MMP)-responsive multi-arm poly(ethylene glycol) (starPEG)/heparin hydrogel on cartilage regeneration parameters in vitro and in vivo.

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The prognosis of colorectal cancer (CRC) is closely linked to the occurrence of distant metastases, which putatively develop from circulating tumor cells (CTCs) shed into circulation by the tumor. As far more CTCs are shed than eventually metastases develop, only a small subfraction of CTCs harbor full tumorigenic potential. The aim of this study was to further characterize CRC-derived CTCs to eventually identify the clinically relevant subfraction of CTCs.

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Xenogeneic or allogeneic chondrocytes hold great potential to build up new cartilage in vivo. However, immune rejection is a major concern for the utility of universal donor-derived cells. In order to verify the reported immune privilege of chondrocytes in vivo, the aim of this study was to assess engraftment of human articular chondrocytes (HAC) in minipig knee cartilage defects and their contribution to cartilage regeneration.

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The prognosis of colorectal cancer is closely linked to the occurrence of distant metastases. Systemic dissemination is most likely caused by circulating tumor cells (CTC). Despite the fundamental role of CTC within the metastatic cascade, technical obstacles have so far prevented detailed genomic and, in particular, phenotypic analyses of CTC, which may provide molecular targets to delay or prevent distant metastases.

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Purpose: Liver regeneration after partial hepatectomy (PH) occurs in conditions of reduced oxygen supply. HIF prolyl hydroxylase enzymes (PHD1, PHD2, and PHD3) are oxygen sensors involved in adaptive response to hypoxia. Specific functions of these PHD enzymes in liver regeneration have, however, remained enigmatic.

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Hypoxia and HIFs (HIF-1α and HIF-2α) modulate innate immune responses in the setting of systemic inflammatory responses and sepsis. The HIF prolyl hydroxylase enzymes PHD1, PHD2 and PHD3 regulate the mammalian adaptive response to hypoxia; however, their significance in the innate immune response has not been elucidated. We demonstrate in this study that deficiency of PHD3 (PHD3(-/-)) specifically shortens the survival of mice subjected to various models of abdominal sepsis because of an overwhelming innate immune response, leading to premature organ dysfunction.

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Background: Aldehyde dehydrogenase 1 (ALDH1) has been characterised as a cancer stem cell marker in different types of tumours. Additionally, it plays a pivotal role in gene regulation and endows tumour cells with augmented chemoresistance. Recently, ALDH1A1 has been described as a prognostic marker in a pancreatic cancer tissue microarray.

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