摘要:
The present invention relates to biodegradable and bioerodible polyurethanes with a controlled degradation time and the use thereof in medicine, in particular as stent covers. The polyurethanes are composed of substantially hydrophobic block ABA poly(ester-ether) diols, hydrophilic polyoxyalkylene polymer, diisocyanate and a low-molecular polyol.
摘要:
Self-expanding biodegradable stent comprising a base structure consisting of interlaced biodegradable fibres, characterized in that the core polymeric fibre containing an x-ray opaque filler is covered with an additional polymer, or the polymeric core fibre is provided with a uniformly dispersed x-ray opaque matter, or the polymeric core fibre is coated with a polymer in which an x-ray opaque matter is uniformly dispersed, the interlaced fibres forming the complete basic structure of the stent being also coated with a dispersion of a an x-ray opaque filler and with a polymer, said coatings forming a biodegradable foil provided on the basic structure of the stent and encapsulating an active substance, said active substance being selected from the group of substances including medicaments; proteins, enzymes/genes; stem cells or radioactive substances used for the Ideal treatment of tumors. 2. Method of manufacturing a self-expanding biodegradable stent having a base structure consisting of interlaced biodegradable fibres, characterized sn that it comprises the steps of covering the core polymeric fibre containing an x-ray opaque filler with an additional polymer, or providing the polymeric core fibre with a uniformly dispersed x-ray opaque matter, or coating the polymeric core fibre with a polymer in which an x-ray opaque matter is uniformly dispersed, followed by the step of coating the interlaced fibres forming the complete basic structure of the stent with a dispersion of a an x-ray opaque filler and with a polymer in order to provide a biodegradable foil on the basic structure of the stent, in which foil an active substance is encapsulated, in which step the stent provided with an x-ray opaque filler undergoes heat treatment and then it is coated with a biodegradable elastic foil made of x-ray opaque fibres containing a first medicament and after having been prepared in this manner the stent is subjected to heat treatment for the second time and recoated with a further, thinner biodegradable foil containing a second, different medicament.
摘要:
A self - expanding non - degradable dual plastic stent being conical in shape is provided with an anti -migration segment (4) and with extracting wires at its proximal end and with an anti-reflux valve (6) at its distal end. The stent is made of two different non - degradable fibres, namely of the PEEK-based carrying fibre (2) and the radiopaque fibre (3), and coated with a silicone foil, the carrying fibre (2) forming the principal skeleton of the stent (1) and the radiopaque fibre (3) enhancing the visibility of the same, the carrying fibre (2) being made of a plastic material selected from the group including PEEK, PEAK, PEK, PEKK, PEKKEK and the other fibre being made of PU+W. The stent (1) is further provided with a pull -tie (5). A method of manufacturing said non - degradable dual conical plastic stent is described, wherein initially the stent is knitted from the first fibre by means of a braiding machine so that it assumes a tubular/ slightly conical shape having the proximal end atraumatic and the distal end traumatic, then the skeleton of the stent is placed oh a mandrel and the other, 1 radiopaque fibre is enlaced into it, both the fibres being laid side by side, afterwards the mandrel with the stent attached to it is removed from the braiding machine and placed into a thermal device where the shape of the stent is thermally fixated by being subjected to a temperature between 120 °C and 250 °C, preferably between 140 °C and 200 °C, during a time interval from 10 to 120 minutes, preferably from 20 to 40 minutes, and finally the stent is provided with the anti -migration segment at its proximal end, said segment comprising one or more fibres forming a ripple at the proximal end of the stent, said ripple adjoining the skeleton of the stent from outside.
摘要:
The surface of the biodegradable stent is made as complex fine mesh in shape of rounded ( 2.1 ) rings ( 2 ) and the stent is tubular or conical. Favourably the stent will be made of degradable polymer thread and can be covered externally by the biodegradable covering.
摘要:
The present invention relates to a transmural, self-expanding biodegradable stent (1) for the use of treating collections complicating acute and chronic pancreatitis. The stent is compressible for insertion through the gastric or duodenal wall and into the collections. The stent expands after insertion to stay in place by the specific dimensions of the stent.