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Introduction to Host-Biomaterial Interactions
Published in Nina M. K. Lamba, Kimberly A. Woodhouse, Stuart L. Cooper, Polyurethanes in Biomedical Applications, 2017
Nina M. K. Lamba, Kimberly A. Woodhouse, Stuart L. Cooper
The coagulation system consists of a number of proteins that react in a cascade-like fashion,9 and has been described as a biological amplifier with positive and negative feedback. The principal role of the coagulation system of the blood is to stabilize the platelet plug formed in the initial stages of hemostasis by the formation of a fibrin network from its precursor fibrinogen. Activation of the coagulation cascade can occur via one of two mechanisms; the intrinsic pathway, or the extrinsic pathway. The intrinsic pathway is activated on contact with surfaces such as glass or collagen. The extrinsic pathway is activated by tissue thromboplastin, or factor III (FIII), which is released into the blood on damage to blood vessels and surrounding tissues. Both activation mechanisms join a common pathway, terminating with the formation of the fibrin network. The system can be considered in three stages. The first is the generation of prothrombin activator (FXa), the second is the conversion of factor II (FII, prothrombin) to thrombin by the action of the prothrombin activator. The last step is the formation of fibrin from fibrinogen, (FGN, factor I, FI), catalyzed by thrombin. Fibrin formation is intimately related to platelet aggregation in the complex thrombus. Fibrin strands surround and link the platelet aggregates to stabilize the thrombus as it forms.
Microfluidics-Based Point-of-Care Diagnostic Devices
Published in Raju Khan, Chetna Dhand, S. K. Sanghi, Shabi Thankaraj Salammal, A. B. P. Mishra, Advanced Microfluidics-Based Point-of-Care Diagnostics, 2022
Ashis K. Sen, Amal Nath, Aremanda Sudeepthi, Sachin K. Jain, Utsab Banerjee
When a blood vessel is damaged, there is a possibility of blood loss, and the prevention of such loss is known as hemostasis. This process consists of four mechanisms – (i) constriction of the vascular wall, (ii) formation of a platelet plug, (iii) formation of a blood clot due to coagulation, and (iv) formation of fibrous tissues in the clot to permanently close the vascular wall. Activation of coagulation leads to a gradual increase in blood viscosity and the physical properties of blood change from that of a viscoelastic fluid to a viscoelastic solid after the formation of cross-linked fibrin clot [94]. The study of blood coagulation is carried out in a device [95] which consists of a paper-based test strip incorporating a fiberglass sample pad, a nitrocellulose analytical membrane, and a cellulose wicking pad. The assembled strip is inserted into a plastic housing with openings for sample dispensing and flow observation, as shown in Figure 4.5(e). Constant monitoring of glucose levels is of paramount importance for a diabetes patient under insulin medication [96]. A simple paper-based analytical device capable of rapid and quantitative detection of metabolites, including glucose, cholesterol, lactate, and alcohol has been designed [97] to operate in conjunction with a commercial handheld glucometer (i.e., TRUEtrack from CVS/Pharmacy). The device is a strip consisting of microfluidic channels, carbon electrodes, and silver wires on one sheet of chromatography paper. The device, as shown in Figure 4.5(f), typically requires a volume of ∼1 µL of the fluid sample (blood, plasma, or aqueous solution) to wet the channels completely, and the chemical reagents required for the tests are stored in the detection zone of the device. Malaria has been a primary cause of mortality and morbidity in tropical and subtropical counties, resulting in over one million deaths every year around the globe [98]. Current research is also exploring various low-cost paper-based devices to detect malaria in rural areas [99].
Incorporation of tissue factor-integrated liposome and silica nanoparticle into collagen hydrogel as a promising hemostatic system
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Zhuang Shi, Chengcheng Shi, Chengkun Liu, Haiyan Sun, Sihan Ai, Xiaodan Liu, Haoyu Wang, Yunsong Gan, Huajie Dai, Xiaoqiang Wang, Fang Huang
Various hemostatic materials have been developed in the form of bandages, gauzes, hydrogels, glues, powders and so on [1], which are thought to participate in different aspects of hemostatic mechanisms. For example, alginate hydrogels containing TF-integrated liposomes were designed, which can tune the release of the proteoliposomes and thus the extrinsic clotting pathway [9], while a combination of chitosan with polyethylene and silica to form a flexible gauze integrated the tissue adhesiveness of chitosan with the intrinsic pathway activating capacity of negatively charged silica [10]. Collagen-based materials are reported to mainly impart platelet plug formation to bleeding wound site [11, 12]. Up to date, no research has been reported to modularly combine the hemostasis-stimulating properties of different materials to find an optimum system that can promote simultaneously both primary hemostasis and the two pathways of secondary hemostasis. Here we wish to present preliminary results of such an integrated system, which was fabricated by incorporating TF-integrated liposomes and silica nanoparticle into collagen hydrogels (Figure 1a).
Clinical effectiveness and versatility of a sealing hemostatic patch (HEMOPATCH) in multiple surgical specialties
Published in Expert Review of Medical Devices, 2018
Kevin M. Lewis, Shelly Ikeme, Tolu Olubunmi, Carl Erik Kuntze
The first hemostatic agents were gelatin and oxidized cellulose pads [10,11]. These agents continue to serve as the basis for several hemostatic agents. GELFOAM (Pfizer, Inc., New York, NY, USA) was the first gelatin pad introduced. It induces hemostasis by binding fibronectin to which platelets adhere, spread, and activate [12–14]. SURGICEL Original (Ethicon Inc., Somerville, NJ, USA) was the first oxidized cellulose introduced. It induces hemostasis by generating a primary local hemostyptic action and secondary platelet activation to form a temporary platelet plug [15]. These agents offered a low-cost and high ease-of-use solution to treat mild bleeds.