摘要:

AbstractA rapid mixing and sampling technique was used to study the permeability characteristics of semipermeable aqueous microcapsules (artificial cells). Urea, creatine, creatinine, uric acid, glucose, sucrose, and salicylic acid equilibrated rapidly across nylon microcapsules of 207 μ diameter (e.g.,T1/2for urea of 3.4 sec). From these results the permeability constants were calculated (e.g.,Pfor urea of 2 × 10−4cm/sec). Very much the same permeability constants were found for collodion microcapsules. The equivalent pore radius of the membrane of the nylon microcapsules were estimated to be 1

ISSN:0021-9304    

DOI:10.1002/jbm.820020202

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

摘要:

AbstractPrevious observations of pseudointimal organization within impermeable cardiovascular prostheses indicated that rapid spontaneous healing was dependent upon proximity of host vascular tissue at the suture line. Autologous connective tissue fragments were prepared from skeletal muscle biopsies by blender‐mincing muscle tissue. The fragments were embedded in the fabric used to line the inner wall of arterial prostheses. A tightly fitting piston was drawn through the prosthesis, forcing the suspended tissue fragments to flow around the piston and become entwined in the loops of the velour fabric. The arterial prostheses prepared in this way were inserted as replacements for segments of canine abdominal aorta. Thisin vivoculture system supported cellular proliferation and pseudointimas healed uniformly. Pseudointimas of paracorporeal pumps in operation for as long as 5 weeks did not show signs of healing. The same principle of filtration of tissue fragments into a lining fabric was applied to diaphragms of left ventricular bypass pumps. This type of paracorporeal pump supportedin vivoculture of implanted fragment

ISSN:0021-9304    

DOI:10.1002/jbm.820020203

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

摘要:

AbstractThe critical need for purchase specifications for implantable biomedical materials is the focus of this contribution. The elements in development of such specifications are presented with specific reference to a widely used high polymer, polytetrafluoroethylene. A specification for sheet or film of this plastic, as instituted by a major urban hospital, is presented in detail.

ISSN:0021-9304    

DOI:10.1002/jbm.820020204

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

摘要:

AbstractMaximum extraction stress and integrated extraction work were measured for sutures implanted for 3, 7, and 14 day periods. Six common non‐absorbable sutures, representative of braided and monofilamentary forms, were implanted subdermally and were used for cutaneous incision closure with purebred pointer dogs. The data show: (1) Braided sutures, polyester/Teflon, silk‐type B, and silk–silicone interacted with peripheral tissue to a significantly greater degree than the monofilamentary types, nylon, polypropylene, and polyethylene; (2) polyester–Teflon braided suture interacted to a lesser degree than the other braided sutures; (3) the relatively intense interaction of plain silk and silicone‐treated silk appears to reflect the combined effects of mechanical aspects of braiding and of biochemical response; and (4) all braided sutures swelled over the implantation periods with as much as a 70% increase in diameter after 14 days

ISSN:0021-9304    

DOI:10.1002/jbm.820020205

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

摘要:

AbstractATP‐diphosphohydrolase, trypsin, and chymotrypsin have been insolubilized by lattice‐entrapment using hydrophilic polyacrylamide gel and hydrophobic Silastic matrices. The entrapped enzymes were stable and unaffected by washing or wet storage. Thermal inactivation properties of polyacrylamide‐entrapped ATP‐diphosphohydrolase were different from those of the same enzyme in solution. Several substrates were used for each of the proteolytic enzymes. Esterase activities of both trypsin and chymotrypsin were unaltered by entrapment within Silastic. The entrapment of enzymes and other active proteins is potentially of consequence in continuous‐flow substrate conversion systems. Silastic with a surface proteolytic activity derived from an entrapped enzyme is of possible medical utility for implantation

ISSN:0021-9304    

DOI:10.1002/jbm.820020206

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

摘要:

AbstractA hydrophilic plastic material (USA trademark Hydron), developed by Wichterle and Lím, was used as a sponge for augmentation of breasts in the clinic for plastic surgery. The preparation of the prosthesis and the operational procedures are described

ISSN:0021-9304    

DOI:10.1002/jbm.820020207

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

摘要:

AbstractThe paper sums up experimental data for the preparation of a collagen sponge to be used as hemostaticum or tampon. Optimal conditions were found with respect to the degree of porosity and tanning of the sponge in order to attain both these properties separately. The native sponge partially ages by storage and its stability increases with increase of temperature during storage. The heat‐induced stability of the sponge, however, is not as great as the stability induced by tanning agents. No effect of irradiation on the stability of the collagen sponge was found within doses of 1–10 Mrad. The speed of resorption and tissue reaction of the subcutaneously implanted native and tanned collagen sponge was followed up and no hypersensitive reaction by the tissue was found. However, different reactions of the tissue to native and to tanned sponge were ascertai

ISSN:0021-9304    

DOI:10.1002/jbm.820020208

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

摘要:

AbstractAn implant test, in which 0.3–0.5 g of solidifying or polymerizing material was injected into the belly wall of rats, was used to compare the tissue reactions to four materials. A histological survey was made of the tissue reactions to stainless steel pins, zinc oxide–eugenol mixtures, cold‐cure acrylic resin, silicate dental cement, and to a polymer–filler system (dental restorative). The irritant effects of the implant on the fibrous encapsulation about these foreign bodies were used to assess the toxicity of the material. Implanted stainless steel pins acted as a control for comparison. Zinc oxide–eugenol and silicate cement produced necrosis when injected in the mixed but unset state; the irritation continued for 30 days after implantation and was sufficient to impede fibrous encapsulation. Fibrous encapsulation about injections of cold cure acrylic resin and an experimental composite of polymer and filler occurred 5 days after similar encapsulation about implanted stainless steel implants. The inclusion of a relatively inert filler decreased the initial reaction to a monomer–catal

ISSN:0021-9304    

DOI:10.1002/jbm.820020209

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820020211

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820020201

出版商:John Wiley&Sons, Inc.    

年代:1968

数据来源: WILEY