Inorganic-organic melt-extruded hybrid filaments and medical applications thereof

Abstract

Inorganic-organic hybrid, melt-extruded filaments having variable cross-sectional geometry with a cross-sectional area ranging between 100μ 2 and 4 mm 2 include an inorganic component that comprises at least 10 weight percent of the total system and is present as dispersed micro-/nanoparticles in an organic absorbable or non-absorbable matrix representing no more than 90 weight percent. Hybrid filaments are particularly useful for the production of absorbable/disintegratable coil components of an absorbable/disintegratable endoureteral stent and radiopaque surgical markers or sutures.

1 . An inorganic-organic hybrid melt-extruded filament comprising at least about 10 weight percent of at least one type of inorganic micro-/nanoparticles uniformly dispersed in a thermoplastic organic polymeric matrix. 
   
   
       2 . An inorganic-organic hybrid melt-extruded filament as in  claim 1  wherein the inorganic micro-/nanoparticles are selected from the group consisting of sulfates of multivalent metals, phosphate salts, polymeric phosphate glasses, polymeric phosphate glass ceramics, phosphate ceramics, ZrO 2 , and basic bismuth carbonate. 
   
   
       3 . An inorganic-organic hybrid melt-extruded filament as in  claim 2  wherein the multivalent metals are selected from the group consisting of Mg, Ca, Ba, Sr, Zr, Zn, Bi, and Fe. 
   
   
       4 . An inorganic-organic hybrid melt-extruded filament as in  claim 2  wherein the phosphate salts are selected from the group consisting of CaHPO 4 , K 2 HPO 4 , KH 2 PO 4 , Na 2 HPO 4 , NaH 2 PO 4 , Ca 3 (PO 4 ) 2 , Ca 10 (OH) 2 (PO 4 ) 6 , and Ca 2 P 2 O 7 . 
   
   
       5 . An inorganic-organic hybrid melt-extruded filament as in  claim 2  wherein the polymeric phosphate glasses are derived from P 2 O 5 , CaO, and at least one oxide selected from the group consisting of ZnO, SrO, Na 2 O, K 2 O, SiO 2 , Fe 2 O 3 , and ZrO 2 . 
   
   
       6 . An inorganic-organic hybrid melt-extruded filament as in  claim 2  wherein the organic polymeric matrix comprises a thermoplastic absorbable polyester having chain sequences derived from at least one cyclic monomer selected from the group consisting of ε-caprolactone, glycolide, a lactide, p-dioxanone, 1,5-dioxepan-2-one, trimethylene carbonate, and a morpholinedione. 
   
   
       7 . An inorganic-organic hybrid melt-extruded filament as in  claim 1  wherein the organic polymeric matrix comprises an absorbable polyether-ester. 
   
   
       8 . An inorganic-organic hybrid melt-extruded filament as in  claim 7  wherein the absorbable polyether-ester comprises a polyethylene glycol end-grafted with at least one cyclic monomer selected from the group consisting of ε-caprolactone, glycolide, a lactide, trimethylene carbonate, p-dioxanone, 1,5-dioxepan-2-one and a morpholinedione. 
   
   
       9 . An inorganic-organic hybrid melt-extruded filament as in  claim 1  wherein the polymeric organic matrix comprises polypropylene. 
   
   
       10 . An inorganic-organic hybrid melt-extruded filament as in  claim 1  comprising a monofilament having a diameter of less than about 2 mm and wherein the inorganic micro-/nanoparticles comprise BaSO 4  and the organic polymer matrix comprises an absorbable polyester comprising chain sequences derived from at least one cyclic monomer selected from the group consisting of ε-caprolactone, glycolide, a lactide, p-dioxanone, 1,5-dioxepan-2-one, trimethylene carbonate, and a morpholinedione, wherein the monofilament is heat-set into a coil for use as a component of an endoureteral stent. 
   
   
       11 . An inorganic-organic hybrid melt-extruded filament comprising a monofilament having a diameter of less than about 2 mm and wherein the inorganic micro-/nanoparticles comprise BaSO 4  and the organic polymer matrix comprises an absorbable polyether-ester. 
   
   
       12 . An inorganic-organic hybrid melt-extruded filament as in  claim 11  wherein the absorbable polyether-ester comprises a polyethylene glycol grafted with at least one cyclic monomer selected from the group consisting of ε-caprolactone, glycolide, a lactide, p-dioxane, 1,5-dioxepan-2-one, trimethylene carbonate and a morpholinedione. 
   
   
       13 . An inorganic-organic hybrid melt-extruded filament as in  claim 12  wherein the inorganic micro-/nanoparticles comprise BaSO 4 . 
   
   
       14 . An inorganic-organic hybrid melt-extruded filament as in  claim 13  as a component of an endourological stent. 
   
   
       15 . An inorganic-organic hybrid melt-extruded filament as in  claim 14  wherein the endourological stent is an endoureteral device comprising the hybrid monofilament as a coil covered with a knitted absorbable mesh and a binder surface coating. 
   
   
       16 . An inorganic-organic hybrid melt-extruded filament as in  claim 15  for use as a radiopaque component of a medical device. 
   
   
       17 . An inorganic-organic hybrid melt-extruded filament as in  claim 1  for use as a radiopaque surgical device selected from the group consisting of absorbable sutures, absorbable stents, non-absorbable retraction tape, and non-absorbable sutures, wherein the inorganic micro-/nanoparticles comprise BaSO 4 . 
   
   
       18 . An inorganic-organic hybrid melt-extruded filament as in  claim 1  as a marker for use in cancer-related surgeries. 
   
   
       19 . A process for making a filament comprising the steps of:
 providing inorganic micro-/nanoparticles having a diameter of less than about 10μ;   placing the inorganic micro-/nanoparticles into a polymerization reactor;   polymerizing an organic matrix in the reactor while maintaining constant high shear stirring to insure uniform dispersion of the inorganic particles in the polymerization charge, thereby forming an inorganic-organic hybrid composition comprising at least about 10 weight percent of inorganic micro-/nanoparticles uniformly dispersed in a thermoplastic organic polymeric matrix; and   melt extruding the hybrid composition.