[Possibilities of testing solid polymers using cell cultures].

With some exceptions, surface chemistry had little effect on platelet and leukocyte activation, and cell deposition, by scanning electron microscopy after blood exposure and clotting times among a group of 12 unmodified and plasma modified tubings. All materials activated platelets and leukocytes to detectable levels, although some materials increased the value of one activation parameter but not another. Unmodified materials [polyethylene (PE), Pellethane (PEU), latex, nylon, and Silastic] and modified materials (H(2)O plasma treated PE and PEU, CF(4) plasma treated PE, fluorinated PEU, NH(4) plasma treated PEU, polyethylene imine treated PEU, and heparin treated PEU) were characterised by XPS and contact angle. The objective of this project was to define a series of assays for the evaluation of hemocompatibility of cardiovascular devices with a view to clarify the specific requirements of ISO-10993-4, and to define an appropriate screening program for new blood contacting biomaterials. PE, PE--CF(4), PE--H(2)0, PEU--F, latex, and PEU-heparin were the exceptions to the general observations, although each behaved differently. PE proved to be least reactive, whereas PE-CF(4) was most reactive by several assays. Platelet microparticle formation (determined by flow cytometry), PTT, postblood exposure SEM, total SC5b-9, C3a, and platelet and leukocyte loss (cell counts) were able to distinguish differences among these materials, and often, but not always, showed expected correlations.

Biocompatible Materials↗

PubMed2001

Novel sol-gel bioactive fibers.

Bioactive fibers were produced using a sol-gel method. The rheological properties of two different sol compositions prepared from a mixture of TEOS, phosphorous alkoxide and calcium nitrate, or calcium chloride in a water-ethanol solution, are reported. The sols were extruded through a spinneret to produce continuous 10 microm-diameter fibers. Discontinuous fibers and fibrous mats were prepared by air-spraying the multicomponent sols. The sol-gel fibers were converted to the bioactive fibers by three different thermal treatments at either 600 degrees, 700 degrees, or 900 degrees C for 3 h. SEM, BET, EDX, and FTIR were used to characterize the morphology and structure of the fibers. The BET measured surface area of the fibers sintered at 900 degrees C was 0 m(2)/gm compared to a value of 200 m(2)/gm for a typical sol-gel-derived particle of similar composition. Both the continuous and discontinuous fibers exhibited in vitro bioactivity in a simulated body fluid.

Biocompatible Materials↗