13456 results about "Polylactic acid" patented technology

A method is given for treating a subterranean formation penetrated by a wellbore with a viscosified fluid. The fluid contains a solid hydrolysable polyacid that upon dissolution and hydrolysis releases an acid that is a breaker for the viscosifying system. Suitable solid hydrolysable polyacids include polylactic acid and polyglycolic acid. The fluid also contains a pH control agent, present in an amount sufficient to neutralize any acid present in the solid hydrolysable polyacid before the injection and to neutralize any acid generated by the solid hydrolysable polyacid during the injection, so that the acid breaker is not available to break the fluid during the injection. In one embodiment the viscosifier is a viscoelastic surfactant fluid system and the solid hydrolysable polyacid is of a size selected to be a fluid loss additive, for example in fracturing or gravel packing. In another embodiment, the solid hydrolysable polyacid is used in particles sufficiently small that they enter the pores of the formation. In either case, the viscosifier is broken after the solid releases more acid than can be neutralized by the pH control agent.

A biopsy site marker having at least one small marker body or pellet of bioresorbable material such as gelatin, collagen, polylactic acid, polyglycolic acid which has a radiopaque object, preferably with a non-biological configuration. The at least one bioresorbable body or pellet with a radiopaque object is deposited into the biopsy site, by an delivery device that includes an elongated tubular body with a piston slidable within the tubular body. One end of the tube is placed into the biopsy site. At least one but preferably several marker bodies or pellets are deposited sequentially into the biopsy site through the tube. At least the bioresorbable materials of the detectable markers remain present in sufficient quantity to permit detection and location of the biopsy site at a first time point (e.g., 2 weeks) after introduction but clear from the biopsy site or otherwise do not interfere with imaging of tissues adjacent the biopsy site at a second time point (e.g., 5-7 months) after introduction.

A surgical fastener apparatus, for securing a surgical mesh material to body tissue including a pair of anchors each having a retaining structure formed on an outer surface thereof; and a suture tether interconnecting the pair of anchors to one another. The pair of anchors have a substantially cylindrical body having a conically tapered distal end and a planar proximal end. The retaining structure includes a series of semi-circular angled projections having a planar proximal surface and a tapered distal end, wherein a center of each of the angled projections is spaced a distance from a longitudinal central axis of the body portion. The surgical fastener is made from a bioabsorbable material which reabsorbs into said body tissue at an appropriate rate, such as for example, polyglycolic acid and polylactic acid.

Connective tissue, including neo-tendons and ligaments, has been constructed using biodegradable synthetic scaffolds seeded with tenocytes. The scaffolds are preferably formed from biodegradable fibers formed of a polymer such as polyglycolic acid-polylactic acid copolymers, and seeded with cells isolated from autologous tendon or ligament by means of enzymatic digestion or direct seeding into tissue culture dishes from explants. The cell polymer constructs are then surgically transplanted to replace missing segments of functioning tendon or ligament.

Polymeric materials and products, including sheet flooring materials prepared from the polymeric materials, and processes for preparing the polymeric materials, are disclosed. The polymeric materials include a polylactic acid-based polymer in combination with plasticizer and a compatibilizer, and optionally include a filler. The polymeric material can include between about 30 to about 50 percent by weight polyvinyl chloride, polyethylene glycol, polyglycolide, ethylene vinyl acetate, polycarbonate, polycaprolactone, polyhydroxyalkanoates, or polyolefins modified with polar groups, for example, ionomers. The plasticizer is typically an epoxidized vegetable oil or esterified and epoxidized vegetable oil and is typically present in an amount of between about 10 and about 50% by weight. In some embodiments, the compatibilizer is a polyolefin modified with one or more polar functional groups, and is typically present in an amount of between about 5 and about 10% by weight. The material can be used in decorative surface coverings, such as a floor coverings, particularly when it is in the form of a polymeric sheet. The polymeric material can be present in at least one layer of a floor covering, which floor covering can also include one or more additional layers such as wear layers, foamed or foamable layers, top coat layers and design layers. The additional layers can also include the polymeric material.

Biopsy localization devices and methods made according to the invention include a bioresorbable body, such as a gelatin, polylactic acid, and / or polyglycolic acid. The bioresorbable body preferably carries a radiopaque marker. The bioresorbable body preferably swells to fill the biopsied open region. The bioresorbable body and radiopaque marker permit the biopsy site to be relocated by various techniques, including mammography and ultrasound.