Biomedical subjects

C W Wade

Publications and source records attributed to C W Wade.

16 recordsLinked to original sources

PubMed1986

Synthesis and bioevaluation of alkyl 2-cyanoacryloyl glycolates as potential soft tissue adhesives.

A series of alkyl 2-cyanoacryloyl glycolate tissue adhesives were synthesized and characterized by NMR. Physical properties and bond strengths are presented. Within the series, bond strength decreased with increasing molecular weight. Corresponding polymers were evaluated by in vitro and in vivo techniques for biocompatibility. In general, in vitro biocompatibility increased with molecular weight. Based on in vitro and in vivo results, the isobutyl and isoamyl derivatives gave polymers that were most biocompatible, however, the entire series was found to be less reactive than poly(methyl 2-cyanoacrylate) and only the isopropyl derivative polymers more reactive than poly(isobutyl 2-cyanoacrylate). Approximately one-third of the isobutyl polymer biodegraded in vivo after 6 weeks.

Adhesiveness↗

PubMed1986

Synthesis and bioevaluation of a rapidly biodegradable tissue adhesive: 1,2-isopropylidene glyceryl 2-cyanoacrylate.

A rapidly biodegradable tissue adhesive, 1,2-isopropylidene glyceryl 2-cyanoacrylate, was synthesized and characterized by NMR. Bond strength was determined. Three types of corresponding polymers were prepared and evaluated for in vitro and in vivo toxicity. The polymers were generally found to be in the moderately toxic and toxic groups similar to the lower alkyl 2-cyanoacrylates.

Adhesiveness↗

PubMed1978

Biocompatibility testing of polymers: in vitro studies with in vivo correlation.

An in vitro method has been developed for screening of candidate biomaterials in an early phase of their development. The test is based on L-929 mouse fibroblast cultures and their response to powdered polymer samples. It applies microscopic observation for the detection of morphological changes, uses dye exclusion testing for cell viability determination, and utilizes estimation of population doublings as an end point. The test is shown to be reliable and reproducible and is compared to in vivo implantation studies in rats, previously reported.

Animals↗

PubMed1978

Biocompatibility testing of polymers: in vivo implantation studies.

An in vivo method is described for screening polymeric materials for biocompatibility. The test is based on grading acute and subacute tissue reactions at 7 and 28 days, respectively, following implantation in rats. The methods is reproducible and reliable. It is designed to provide uniform test criteria for biocompatibility assessment in the early phases of the development of surgical implant materials.

Animals↗

PubMed1976

Enzyme immobilization on fibrin.

The following conclusions can be drawn concerning the utilization of fibrin to immobilized enzyme systems. Fibrin can be used both as a powder or membrane, to covalently immobilize trypsin with retention of activity. Carbon-14 labeled trypsin can be used to estimate the amount of immobilized enzyme on a proteinaceous support. Significant amounts of noncovalently coupled (adsorbed) enzyme are present on the surface of the support. Esterase activity of the immobilized labeled trypsin was inversely proportional to the amount of attached enzyme. Optimum TAME hydrolysis occurred at pH 8-8.4. The storage stability of trypsin was enhanced. Inhibition of trypsin esterase activity occurred at substrate concentrations greater than 30mM.

Adsorption↗

PubMed1975

Design and fabrication of two types of artificial tendons for evaluation of surgical techniques.

Double-loop tendons of fixed and adjustable lengths, and tendons with inner porous tapes both for anastomosis to tendon stumps have been made from readily available materials. By using stainless steel wire and polymer fibers, breakloads have been obtained that range from 20 to 100 lb and elongations have been reduced to less than 2%. Pore sizes up to 50 times 250 mu2 were achieved by using woven, knitted, and braided polyester tapes. For all tendons, Silastic was used to isolate inner fibers and to effect smooth gliding. Preliminary evaluation of these devices, after being implanted in the feet of chickens for 4 weeks, indicates that anastomotic strength of unions formed by use of loops is about 1000 g compared to more than 2000 for unions formed by tissue ingrowth.

Animals↗

PubMed1975

Physical characteristics and performance of synthetic wound dressings.

From these studies it is concluded that: 1) Physical characteristics of wound dressings can be quantified and evaluated for their contribution to in vivo performance. 2) A total performance scoring system can be reliably used to quantitatively separate series of wound dressings by their in vivo performances. 3) The physical characteristics most determinate of good perfprmance in these 5 series of dressings were undersurface texture and water vapor transmission.

Animals↗

PubMed1974