Selective removal of molecular moieties from plasma of patients can result in tumor regression, auto-antibody clearance, and immune modulation. The ProsorbaR Column consists of highly purified protein A isolated from Staphylococcus and covalently linked to inert silica housed in a polycarbonate device. Protein A acts as an immunoadsorbent to selectively remove immunoglobulin G (IgG) and IgG containing CIC via specific binding to the Fc fragment of IgG. Columns were sterile, disposable devices that remove approximately one gram of IgG from plasma per treatment. As part of a multicenter clinical trial, 8 of 22 (36%) end stage breast cancer patients exhibited objective antitumor responses. Treatment of 24 patients with immune thrombocytopenia resulted in 14 (58%) of patients having objective increases in platelet counts and clearance or significant reduction of anti-platelet antibody. The mechanism of action of this device is unknown at present but may be selective removal of IgG and CIC, and activation of factors such as the complement system which results in enhanced reticuloendothelial system (RES) clearance of CIC. In addition, immune modulation may result due to the stimulation of anti-idiotypic antibodies and selective clonal deletion of auto-antibody producing lymphocyte sub-populations.

Most medical devices utilized in blood storage and transfusion, as well as in many medical and surgical procedures, are manufactured with polyvinylchloride (PVC) plastic containing the plasticizer di(2-ethylhexyl)phthalate (DEHP). During exposure of blood to the plastic surface, the DEHP is leached into the plasma where it is converted to mono(2-ethylhexyl)phthalate (MEHP) by a plasma enzyme in vivo or ex vivo during storage in plastic containers. The toxic effects of MEHP when infused into rats were investigated. The amount of MEHP infused was based on MEHP levels found in a variety of stored blood products (>6 ug/mL in red cell concentrates) and values actually measured during exchange transfusion (5 ug/mL) and cardiopulmonary bypass surgery (2.7 ug/mL). When the circulating level of MEHP in the rat's blood was >125 ug/mL, a greater than 50% decrease in heart rate and blood pressure was observed. This represents a margin of safety of only 25 fold higher than levels measured in humans during exchange transfusions. Although DEHP and MEHP have low oral toxicity, acute exposure by infusion may have lethal effects.

The interaction between a polymer or other foreign surface and soft tissue is determined by a variety of materials and tissue factors. After failing to engulf the foreign body, the classical response is to wall it off. First the site is invaded by macrophages and giant cells and then fibrous connective tissue is laid down. This fibrous connective tissue gradually replaces the cellular matrix and forms the capsule. The composition is mostly collagen and mucopolysaccharides with few cells in the mature capsule. It contains 75–80% water.

When the implant surface represents a sensor and the transport of low molecular weight species across the capsule is necessary for meaningful measurement and response time, the mass transport resistance of the capsule may become a critical factor. This study represents an initial attempt to characterize the diffusion of glucose through fibrous capsules grown around silicone elastomer implants in a rat. Specifically, the study was designed to develop techniques to measure mass transport properties of tissue capsules, to use these techniques to determine effective glucose transport properties at two weeks, four weeks, and ten weeks after implant; and, to use these results along with histological examinations to gain an understanding of the factors which influence mass transport.

From a medical standpoint, sorbent chemicals can be thought of as the converse of drugs. Drugs are chemicals which are given in concentrated form, which distribute within body tissue, and which produce (hopefully) beneficial physiological effects. In medical use, sorbents are exposed to body fluids, accumulate drugs or physiological chemicals within them, and produce (hopefully) beneficial effects. For both sorbents and drugs, the speed of the physiological benefit is usually limited by the rate of distribution of chemicals within the body tissues.

Four glasses were tested as enamel seals between osseous and mucous media on alumina implants. It was found that a perfect enamel adherence on the aluminous substrate is obtained at 1400° C. During enameling the surface of the implant is dissolved in the glass, which leads to the formation of aluminosilicate crystals in the implant/enamel interface. A rapid cooling from 200 to 1°C in water does not provoke fissuring of the enamel for the four glasses tested, which illustrates the good mechanical resistance of the implant/enamel bond. The preliminary in vitro results indicate that hydroxyapatite forms directly within the leached layer developed in plasma (except for KG.X glass).