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Biomedical subjects

A A Beisang

Publications and source records attributed to A A Beisang.

11 recordsLinked to original sources
PubMed1992

Bioplastique: a new biphasic polymer for minimally invasive injection implantation.

The search for prosthetic materials that are biocompatible, nontoxic, and permanent led the authors to develop a micronized, inert, biphasic polymer particle for permanent soft tissue augmentation which neither migrates nor is absorbed by the body. Placed in a bioexcretable gel carrier, these textured microparticles are easily implanted using a specially designed blunt-tipped cannula with local anesthesia on an outpatient basis. Research using this implant material, Bioplastique (Bioplasty, St. Paul, MN), in rabbits has shown that when the textured particle size is maintained within a critical range, neither particle migration nor storage disease occurs. The gel carrier is rapidly phagocytized and replaced by fibrin matrix within a few days. Host collagen then gradually forms a fibrotic capsule around each textured particle, making use of the naturally occurring foreign body reaction to create a stable inplant. After being followed for over two years, Bioplastique has proven to be useful in many clinical applications with few complications.

Animals↗
PubMed1992

Mammalian response to subdermal implantation of textured microimplants.

The development of small, textured implant particles suspended in a hydrogel has allowed for subdermal injection therapy to fill tissue defects. The microimplant particles were placed subdermally into the ears of white New Zealand rabbits in order to characterize the foreign body response and the permanence of the implant. Serial micrometer readings were performed on the implant sites to determine any change in thickness of the augmentation following baseline measurement. An initial increase in the thickness was noted approximately 20-30 days postimplantation, as expected. A stable thickness was noted for the remainder of the experiment. Serial histological sections were performed at irregular intervals from one week to one year. Histology demonstrated a mild foreign body response with collagen surrounding each individual microimplant particle. The response was stable after 30-40 days and has remained stable for over one year. It was determined that the histology demonstrated a Boros 1A type, or nonimmunogenic, low-turnover foreign body reaction.

Animals↗
PubMed1991

Radiolucent prosthetic gel.

The successful use of silicone breast implants is complicated by their interference with mammography. We have evaluated clinically available implant filling materials and found that a new Bio-Oncotic gel approximates the radiolucency of normal breast tissue. Silicone implants completely obscure areas of the breast in mammography. Recently proposed as a filler material, peanut oil is significantly more radiolucent than normal tissue. Physiologic saline solution compares favorably as a tissue-density-simulating substance. However, saline's lack of lubricating properties results in leakage, making it less than optimal. Bio-Oncotic gel is biologically compatible. We conclude that this gel is the most appropriate filler for breast prostheses. Clinical studies are indicated.

Arachis↗
PubMed1991

Bioplastique: a new textured copolymer microparticle promises permanence in soft-tissue augmentation.

Migration, absorption, or toxicity of prosthetic materials has always plagued the plastic surgeon attempting to ameliorate soft-tissue deficiencies and other contour abnormalities. Our previous work to develop textured-surface breast prostheses has led to the development of micronized, inert, biphasic copolymer particles that neither migrate nor become absorbed by the body. These particles are textured, of critical dimension, and, when mixed with a bioexcretable gel vehicle, can be implanted using a special blunt-tipped cannula. Our experimentation in rabbit ears has shown that the bioexcretable gel component is rapidly phagocytized and is replaced by fibrin-like matrix within 3 days. The fibrin is then replaced by host collagen that gradually converts into a fibrotic encasement around each texturized particle. Clinical use of the substance in a variety of soft-tissue deficiencies has been generally effective, with only a few complications, when followed for 1 year.

Adult↗
PubMed1984

Processed bovine cartilage: an improved biosynthetic implant for contour defects.

Irradiated human cartilage has been found to be a superior implant material for correction of contour defects; however, availability problems have prevented this material from gaining wide acceptance. Implantation of processed irradiated bovine cartilage in primates and rabbits, as described here, provides strong evidence that this material performs like irradiated allograft cartilage antigenically and has certain cosmetic advantages over allograft cartilage. Our studies in primates have shown that there is no systemically measurable antibody-antigen reaction, either cellular or noncellular, to irradiated processed bovine cartilage. Neither primary nor second-set provocative implantations produced any measurable rejection. In rabbits, composite grafts of two pieces of irradiated bovine cartilage adjacent to each other were also well tolerated, with no measurable absorption and with capsule formation typical of a foreign body reaction to an inert object.

Animals↗