The In Situ Human Dental Implantome: A First Appraisal

Protein adsorption is the first fundamental interaction between the human body and a foreign surface. The sum of all proteins in this adherent proteinaceous layer comprises the implant proteome. The in situdental implant proteome (implantome) was eluted from four implants of two wettabilities after a 2-min dipping in the humor operationis of maxillar tooth sockets. A mean number of 2056 different polypeptides per implant were identified according to the Xcorr method (Xcorr score ≥ 1.5, n ≥ 2 peptides). In the top 12 proteins comprising ca. 47% of the total abundance, cell-free hemoglobin (26.7%) was the most abundant, followed by fibrinogen (6.4%) and serum albumin (1.8%) with additional 1,800 lower abundance polypeptides, which contained ca. 34 salivary and a similar number of autoimmunogenic polypeptides. Selective enrichment of cell-free hemoglobin on the implant vs. albumin was estimated to 270 fold

Biomaterial and cellular implants:foreign surfaces where immunity and coagulation meet

Exposure of blood to a foreign surface in the form of a diagnostic or therapeutic biomaterial device or implanted cells or tissues, elicits an immediate, evolutionarily conserved thrombo-inflammatory response by the host. Primarily designed to protect against invading organisms following an injury, this innate response features instantaneous activation of several blood-borne, highly interactive and well-orchestrated cascades and cellular events that limit bleeding, destroy and eliminate the foreign substance/cells, and promote healing and a return to homeostasis via delicately balanced regenerative processes. In the setting of blood-contacting synthetic or natural biomaterials and implantation of foreign cells/tissues, innate responses are robust, albeit highly context-specific. Unfortunately, they tend to be less than adequately regulated by the host's natural anti-coagulant/anti-inflammatory pathways, thereby jeopardizing the functional integrity of the device, as well as the health of the host. Strategies to achieve biocompatibility with a sustained return to homeostasis, particularly while the device remains in situ and functional, continue to elude scientists and clinicians. In this review, some of the complex mechanisms by which biomaterials and cellular transplants provide a "hub" for activation and amplification of coagulation and immunity - thrombo-inflammation - will be discussed, with a view toward the development of innovative means of overcoming the innate challenges.

Effect of Preparation Process on Surface Quality and Microstructure of Titanium Sheet

At present, domestic cold-rolled titanium sheets have many surface defects, which are significantly different from foreign surface quality. This paper mainly studies the differences in the microstructure and performance of titanium plates GR1 and GR2 imported from Japan and domestic titanium plates TA1, and analyzes the causes of surface defects to solve the problem about TA1. The surface properties of different materials were observed. The mechanical properties of the materials were obtained by room temperature tensile test. The surface roughness of the three materials was tested. The microstructure and composition of the three materials were characterized by SEM, EDS and XRD. The results show that the surface of GR1 and GR2 is brighter and has no obvious chromatic aberration. The surface chromatic aberration of TA1 is larger. The mechanical properties of TA1 are the best. The tensile strength and yield strength of rolling are 325.19MPa and 271.17MPa, respectively, and the lateral direction is 329.19MPa and The roughness of 303.15MPa, GR1 and GR2 is slightly lower than that of TA1. The black area on the surface of TA1 is loose and the oxygen content is high. The pole figure of GR1, GR2 and TA1 are obtained. Keywords: Cold-rolled titanium sheets; Chromatic aberration; Mechanical properties; SEM; Texture

Complications of Implanted Nonbiologic Devices—An Overview

Under physiologic conditions, blood is contained within the vascular space lined with smooth endothelial cells. When various devices made of nonbiologic material are implanted, blood will be exposed to a foreign surface. A series of events ensue and may lead to many complications, including thrombosis, hemolysis, thrombocytopenia, bleeding, infection, and malfunction of the device. The incidence, manifestations, and special characteristics of these complications vary with different types of implanted devices. However, they have in common an important pathogenic pathway that of an exposure to a foreign surface. Despite the development of improved versions of these devices, more research on the causative factors of these complications is needed to take preventive and corrective measures, particularly those that enhance the process of healing by re-endothelialization of the foreign surface. This article is a brief review of the complications encountered in blood-contacting devices.

Inhibition of Factors XI and XII for Prevention of Thrombosis Induced by Artificial Surfaces

Exposure of blood to a variety of artificial surface induces contact activation, a process that contributes to the host innate response to foreign substances. On the foreign surface, the contact factors, factor XII (FXII), and plasma prekallikrein undergo reciprocal conversion to their fully active protease forms (FXIIa and α-kallikrein, respectively) by a process supported by the cofactor high-molecular-weight kininogen. Contact activation can trigger blood coagulation by conversion of factor XI (FXI) to the protease FXIa. There is interest in developing therapeutic inhibitors to FXIa and FXIIa because these activated factors can contribute to thrombosis in certain situations. Drugs targeting these proteases may be particularly effective in thrombosis triggered by exposure of blood to the surfaces of implantable medical devices. Here, we review clinical data supporting roles for FXII and FXI in thrombosis induced by medical devices, and preclinical data suggesting that therapeutic targeting of these proteins may limit surface-induced thrombosis.

Clinical evaluation of the air-handling properties of contemporary oxygenators with integrated arterial filter

Gaseous microemboli (GME) may originate from the extracorporeal circuit and enter the arterial circulation of the patient. GME are thought to contribute to cerebral deficit and to adverse outcome after cardiac surgery. The arterial filter is a specially designed component for removing both gaseous and solid microemboli. Integration of an arterial filter with an oxygenator is a contemporary concept, reducing both prime volume and foreign surface area. This study aims to determine the air-handling properties of four contemporary oxygenator devices with an integrated arterial filter. Two oxygenator devices, the Capiox FX25 and the Fusion, showed significant increased volume of GME reduction rates (95.03 ± 3.13% and 95.74 ± 2.69%, respectively) compared with both the Quadrox-IF (85.23 ± 5.84%) and the Inspire 6F M (84.41 ± 12.93%). Notably, both the Quadrox-IF and the Inspire 6F M as well as the Capiox FX 25 and the Fusion showed very similar characteristics in volume and number reduction rates and in detailed distribution properties. The Capiox FX25 and the Fusion devices showed significantly increased number and volume reduction rates compared with the Quadrox-IF and the Inspire 6F M devices. Despite the large differences in design of all four devices, our study results suggest that the oxygenator devices can be subdivided into two groups based on their fibre design, which results in screen filter (Quadrox-IF and Inspire 6F M) and depth filter (Capiox FX25 and Fusion) properties. Depth filter properties, as present in the Capiox FX25 and Fusion devices, reduced fractionation of air and may ameliorate GME removal.

Reflections on Quantitative Gamma Imaging of Cell-Surface Interactions

Molecular and cellular interactions with foreign surfaces can be noninvasively measured by isotope imaging techniques. Long available for probing cell behavior, these techniques are now employed in molecular studies of disease progression, such as Alzheimer’s [1]. This paper reviews results obtained by noninvasive dual label gamma scintigraphy for the transient adhesion of platelets and neutrophils to pump-oxygenators during cardiopulmonary bypass (CPB). In this application, characteristic cell-foreign surface adhesion and release patterns are observed during CPB in the pig, as a function of oxygenator design and surface chemistry. Cell distributions in internal organs post-CPB are also affected by these processes. This method can be adapted to other settings where the understanding of protein-cell interactions with native and foreign surfaces is at issue, including fibrinogen-cell interactions, bacterial colonization, etc.

Studies on Fletcher trait and Fitzgerald trait

SummaryThe way by which contact of blood with foreign surface accelerates clotting has been elucidated from the discovery of four rare disorders of blood coagulation; Hageman trait, plasma thromboplastin antecedent (PTA) deficiency, Fletcher trait, and Fitzgerald trait. Interestingly, it was unexpectedly found that Fletcher factor is plasma prekallikrein and Fitzgerald factor is high-molecular-weight kininogen; components of the kinin-generating system, thus disclosing intimate relationships among clotting, fibrinolysis and kinin generation which may be viewed as body’s defense reactions against injury. This review mainly reflects our research on Fletcher trait and Fitzgerald trait during the 1970s in Cleveland.

Imaging of the Development and Therapeutic Response of an In Vivo Fungal Catheter Biofilm

The majority of human pathogens cause disease in a biofilm lifestyle. Biofilms are communities of cells that remain attached to a foreign surface and to each other. The organisms secrete and become embedded in an extracellular polysaccharide matrix. Biofilm infections occur most commonly on implanted medical devices and are quite recalcitrant to antimicrobial therapy. The most common device involved in these infections is the intravenous catheter. More than 5 million intravenous catheters are inserted into patients in the United States annually of which up to 10% become infected with biofilm producing pathogens.