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Statistical Approaches in the Development of Digital Therapeutics
Published in Oleksandr Sverdlov, Joris van Dam, Digital Therapeutics, 2023
Oleksandr Sverdlov, Yevgen Ryeznik, Sergei Leonov, Valerii Fedorov
As another example, consider success stories of the development of various artificial organs, such as an artificial kidney. Hemodialysis as a means of replacing renal function started and developed in the 20th century (Twardowski, 2008). Hemodialyzers evolved from capillary dialyzers and sorbent systems in the 1960s to wearable artificial kidney systems. A recent US FDA 510(k) clearance of the Artificial Kidney (AK) 98 dialysis machine1 highlights a significant milestone in bringing new, improved quality of care for many patients who are on hemodialysis. The AK 98 is a portable and easy-to-use system with encrypted, two-way connectivity that enables the system to pull prescriptions directly from the patient's electronic medical record.1
Organ transplantation
Published in Harold Ellis, Sala Abdalla, A History of Surgery, 2018
The kidneys function as an ultra-filter: water and small molecules (salts and waste products such as urea) are excreted, whereas large molecules are retained or reabsorbed. To produce an ‘artificial kidney’ that will filter out waste products from the blood, a dialysing membrane is required. One such membrane is the patient’s own peritoneum. In 1923, G Ganter used peritoneal dialysis to lower the blood urea of animals in renal failure, and in 1927, H Heusser and H Werder first attempted to relieve uraemic patients by this means. By 1948, over 100 patients of renal failure treated by this technique were reviewed. The results were poor; there were technical problems with the catheters used, the composition of fluid and infection, which led of course to peritonitis. However, there were one or two encouraging successes; for example, in 1946, a case was reported of cure of a patient suffering from complete suppression of urine caused by the precipitation of sulphathiazole crystals in the urine by means of peritoneal dialysis.
Photothermal nanoparticles for ablation of bacteria associated with kidney stones
Published in International Journal of Hyperthermia, 2021
Ilan Klein, Santu Sarkar, Jorge Gutierrez-Aceves, Nicole Levi
Artificial kidney stones were manufactured in our lab based on prior experience by mixing 18 grams of gypsum cement (17.1 g of Plaster of Paris and 0.9 g of Portland cement) with 2 g of Velmix (calcium sulfate powder) with 15 ml of deionized (DI) water [44]. The mixture was cast in small cylindrical molds 10 mm in length and 5 mm in diameter and dried for 4 h at 37 °C. Artificial kidney stones were autoclaved to sterilize prior to inoculation. Kidney stones from patients were obtained after our Institutional Review Board (IRB) approved the protocol and patients signed an informed consent prior to surgery to donate a part of their stones to the study. Patient-derived kidney stones were obtained in a sterile manner and handled under sterile conditions throughout the experiment. They were broken into about 5 mm pieces prior to their use in the laboratory. All experimental groups used the same patient-derived kidney stones and thus replicates of the experimental variables were repeated using kidney stones from multiple patients. A component of the standard of care is for patients to be given prophylactic antibiotics prior to kidney stone disruption. Sample fragments of each patient stone were evaluated by the Wake Forest University Health Sciences Clinical Pathology laboratory and Beck Analytical Services to determine the composition of the stone and to identify the presence of bacteria; however, all stones used in this study were negative for patient-derived bacteria. All stones were weighed before their use in culture experiments.
Flow balance optimization and fluid removal accuracy with the Quanta SC+ hemodialysis system
Published in Expert Review of Medical Devices, 2020
Clive Buckberry, Nicholas Hoenich, Paul Komenda, Mark Wallace, John E Milad
Hemodialysis involves the use of an artificial semi-permeable membrane contained in an artificial kidney known as a dialyzer. During treatment, blood is removed from the patient via an extracorporeal circuit and is passed through the dialyzer before being returned to the patient. Blood flows through the dialyzer and is in contact with the inner surface of the membrane. The outer surface of the membrane is bathed by a continuously flowing fluid (dialysis fluid) made from a precise mixture of electrolytes and purified water. Abnormal patient biochemistry is normalized primarily by diffusion of accumulated uremic toxins into the dialysis fluid, while the fluid gained by the patient between treatments, due to an inability to pass sufficient amounts of urine to achieve homeostasis, is removed by a hydrostatic pressure gradient across the dialyzer membrane, a process referred to as ultrafiltration.
ARTIFICIAL CELL evolves into nanomedicine, biotherapeutics, blood substitutes, drug delivery, enzyme/gene therapy, cancer therapy, cell/stem cell therapy, nanoparticles, liposomes, bioencapsulation, replicating synthetic cells, cell encapsulation/scaffold, biosorbent/immunosorbent haemoperfusion/plasmapheresis, regenerative medicine, encapsulated microbe, nanobiotechnology, nanotechnology
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
It is common knowledge that for the same volume of particles the smaller the particles, the larger would be the total surface area. It is also known that the theoretical diffusion across a membrane is proportional to the total surface area and inversely proportional to its membrane thickness. However, my 1966 analysis of the implication of combining all these factors for artificial cells of micro dimension is way beyond expectation [5]. Figure 6 shows an updated analysis [11] of the theoretical mass transfer of a fixed volume of 0.01 μm membrane thickness artificial cells with different diameters. This is compared to an artificial kidney (haemodialysis) machine with a mass transfer of 1. The mass transfer increases with decreasing diameter of artificial cells so that at the micro diameter range it can increase to 100 times that of an artificial kidney. At the nano diameter range, this can increase to an amazing 1000 times above that of an artificial kidney. Thus, artificial cells of different diameter containing different bioactive material can become efficient micro/nano dialyzer/bioreactor with unlimited possibilities (Figure 5).