Stable measurement of chemistry, immunochemistry, and hematology analytes in a heparin-based anticoagulant with iloprost additive: A promising candidate for the polyvalent blood collection tube.

INTRODUCTION: A polyvalent blood collection tube could potentially reduce the number and volume of blood samples drawn from patients and reduce the risk of tube mix-ups in a point-of-care setting in the emergency department and the intensive care unit. METHODS: Four different concentrations of our experimental heparin anticoagulant with iloprost additive (HEP-ILOP 50 nM, 150 nM, 1000 nM, and 10 µM, respectively) were tested for significant differences and bias performance specifications against EDTA for 29 hematology analytes, and the highest concentration (HEP-ILOP 10 µM) against lithium heparin for 14 chemistry and immunochemistry analytes. Samples were drawn from 79 consenting subjects from the Oncology Department (n = 38) and the Intensive and Intermediary Care Unit (n = 41). RESULTS: For hematology analytes, the HEP-ILOP formulation generally provided stable measurement within optimal requirements within 5 h after sampling (mean 104 ± 56 min), with very little difference between the four HEP-ILOP concentrations. Because of differences in platelet and red blood cell swelling between EDTA and HEP-ILOP, all size-dependent analytes required proportional factorization to produce similar results. Platelet count by impedance similarly required factorization, whereas the fluorescent method provided results identical with EDTA. Chemistry and immunochemistry analytes were within optimal requirements except for potassium, lactate dehydrogenase, and glucose, indicating a cytoprotective effect of iloprost reducing cell metabolism and rupture, thereby producing results closer to in vivo conditions. CONCLUSIONS: Our novel dry-sprayed anticoagulant formulation, HEP-ILOP, is a promising candidate for a polyvalent blood collection tube, enabling the analysis of hematology, chemistry, and immunochemistry analytes in the same tube.

Clot-entrapped blood cells in synergy with human mesenchymal stem cells create a pro-angiogenic healing response.

Blood clots stop bleeding and provide cell-instructive microenvironments. Still, in vitro models used to study implant performance typically neglect any possible interactions of recruited cells with surface-adhering blood clots. Here we study the interaction and synergies of bone marrow derived human mesenchymal stem cells (hMSCs) with surface-induced blood clots in an in vitro model by fluorescence microscopy, scanning and correlative light and electron microscopy, ELISA assays and zymography. The clinically used alkali-treated rough titanium (Ti) surfaces investigated here are known to enhance blood clotting compared to native Ti and to improve the healing response, but the underlying mechanisms remain elusive. Here we show that the presence of blood clots synergistically increased hMSC proliferation, extracellular matrix (ECM) remodelling and the release of matrix fragments and angiogenic VEGF, but did not increase the osteogenic differentiation of hMSCs. While many biomaterials are nowadays engineered to release pro-angiogenic factors, we show here that clot-entrapped blood cells on conventional materials in synergy with hMSCs are potent producers of pro-angiogenic factors. Our data might thus not only explain why alkali-treatment is beneficial for Ti implant integration, but they suggest that the physiological importance of blood clots to create pro-angiogenic environments on implants has been greatly underestimated. The importance of blood clots might have been missed because the pro-angiogenic functions get activated only upon stimulation by synergistic interactions with the invading cells.

Synergistic interactions of blood-borne immune cells, fibroblasts and extracellular matrix drive repair in an in vitro peri-implant wound healing model.

Low correlations of cell culture data with clinical outcomes pose major medical challenges with costly consequences. While the majority of biomaterials are tested using in vitro cell monocultures, the importance of synergistic interactions between different cell types on paracrine signalling has recently been highlighted. In this proof-of-concept study, we asked whether the first contact of surfaces with whole human blood could steer the tissue healing response. This hypothesis was tested using alkali-treatment of rough titanium (Ti) surfaces since they have clinically been shown to improve early implant integration and stability, yet blood-free in vitro cell cultures poorly correlated with in vivo tissue healing. We show that alkali-treatment, compared to native Ti surfaces, increased blood clot thickness, including platelet adhesion. Strikingly, blood clots with entrapped blood cells in synergistic interactions with fibroblasts, but not fibroblasts alone, upregulated the secretion of major factors associated with fast healing. This includes matrix metalloproteinases (MMPs) to break down extracellular matrix and the growth factor VEGF, known for its angiogenic potential. Consequently, in vitro test platforms, which consider whole blood-implant interactions, might be superior in predicting wound healing in response to biomaterial properties.