silicon and Edema

Chronic wounds require frequent dressing changes. Adhesive dressings used for this indication can be damaging to the stratum corneum, particularly in the elderly where the skin tends to be thinner. Understanding the level of damage caused by dressing removal can aid dressing selection.. This study used a novel methodology that applied a stain to the skin and measured the intensity of that stain after repeated application and removal of a series of different adhesive types. Additionally, a traditional method of measuring skin barrier damage (transepidermal water loss) was also undertaken and compared with the staining methodology.. The staining methodology and measurement of transepidermal water loss differentiated the adhesive dressings, showing that silicone adhesives caused least trauma to the skin.. The staining methodology was shown to be as effective as transepidermal water loss in detecting damage to the stratum corneum and was shown to detect disruption of the barrier earlier than the traditional technique.

Topics: Adult; Aged; Bandages; Blister; Body Water; Colorimetry; Edema; Epidermis; Erythema; Female; Humans; Male; Middle Aged; Silicon; Skin Diseases; Staining and Labeling; Surgical Tape; Water Loss, Insensible

The passive biocompatibility of silicon-based electrode arrays was studied in feline cortical tissue. Three types of arrays were used: uncoated, coated with polyimide, and coated with polyimide over an adhesion promoter. Fifteen arrays were implanted for 24 h to determine early tissue reaction to the implantation procedure, and twelve arrays were implanted for 6 months to determine structural and material biocompatibility. Edema and hemorrhage were present around the short-term implants, but involved less than 6% of the total area of the tissue covered by the array. With chronic implants, leukocytes were rarely present and macrophages were found around roughly one-third of the tracks. Remnants of foreign material from the electrodes could be identified in less than 10% of the tracks. Gliosis was found around all tracks, forming an annulus between 20 and 40 microns thick. A capsule was not always present, and never exceeded a thickness of 9 microns. These results suggest that the implantation procedure produces limited amounts of tissue damage, and that the arrays are biocompatible. However, the arrays insulated with polyimide over a primer had significantly greater involvement of macrophages, gliosis, and capsule formation than uncoated arrays and arrays insulated with polyimide without printer, perhaps indicating a reaction to aluminum oxide in the primer.

Topics: Animals; Cats; Cerebral Cortex; Edema; Electrodes, Implanted; Hemorrhage; Lymphocyte Activation; Materials Testing; Prostheses and Implants; Silicon

Topics: Aluminum; Animals; Anti-Inflammatory Agents; Arthritis; Calcium; Edema; Guinea Pigs; Iron; Kininogens; Macrophages; Magnesium; Male; Manganese; Mice; Oxides; Phosphorus; Potassium; Rats; Silicon; Sodium; Sulfur; Time Factors; Titanium; Vascular Resistance

Topics: Antifoaming Agents; Edema; Ethanol; Lung Diseases; Pulmonary Edema; Silicon

Topics: Adenine Nucleotides; Animals; Dextrans; Edema; Oligoribonucleotides; Rats; Silicic Acid; Silicon; Silicosis

Topics: Aerosols; Edema; Lung Diseases; Pulmonary Edema; Silicon; Silicones