Bioseparation compositions and methods for making and using same

Abstract

A composition for use in bioseparation. The composition includes a plurality of hollow particles having a siliceous surface. The composition further includes a surface-modifying agent bonded to the hollow particles. The surface-modifying agent includes a binding segment and a reactive segment. The binding segment includes a silyl group and the reactive segment includes a reactive nitrogen group.

1 . A composition for use in bioseparation, the composition comprising:
 a plurality of hollow particles, the hollow particles comprising a siliceous surface; and   a surface-modifying agent bonded to the hollow particles, wherein the surface-modifying agent comprises a binding segment and a reactive segment, wherein the binding segment comprises a silyl group, and wherein the reactive segment comprises a reactive nitrogen group;   wherein the plurality of hollow particles have an average density between about 0.05 and 0.4 g/ml.   
     
     
         2 . The composition according to  claim 1 , wherein the hollow particles comprise glass bubbles. 
     
     
         3 . The composition according to  claim 1 , wherein a size distribution of the plurality of hollow particles has a span of less than 1.0. 
     
     
         4 . The composition of  claim 1 , wherein a mean particle size of the plurality of hollow particles ranges from about 10 micrometers to about 100 micrometers. 
     
     
         5 . The composition of  claim 1 , wherein the binding segment has a formula:
   —Si(R 1 ) 3-x (R 2 ) x ;
   wherein x=0, 1, or 2;   wherein each group R 1  comprises independently OH −  or a hydrolyzable group from among halo, alkoxy, aryloxy, aralkyoxy, and acyloxy; and   wherein each group R 2  comprises independently a non-hydrolyzable group from among alkyl, aryl, and aralkyl.   
     
     
         6 . The composition of  claim 1 , wherein the surface-modifying agent further comprises a linking segment, the linking segment comprising alkylene, arylene, or both, and optionally further comprising —NH— or alkyleneoxy, or both. 
     
     
         7 . The composition of  claim 1 , wherein the reactive segment has a formula:
   —N(R 3 ) 2 , or salts thereof;
   wherein each group R 3  comprises independently hydrogen, alkyl, aryl, or aralkyl.   
     
     
         8 . A method for making a bioseparation composition, the method comprising:
 size fractionating a first plurality of hollow particles having a first particle size distribution with a first span to form a second plurality of hollow particles having a second particle size distribution with a second span that is less than the first span; and   surface-modifying either or both of the first and second plurality of hollow particles with a surface modifying agent to form surface-modified hollow particles, wherein the surface-modifying agent comprises a binding segment and a reactive segment, wherein the binding segment comprises a silyl group, and wherein the reactive segment comprises a reactive nitrogen group.   
     
     
         9 . The method of  claim 8 , wherein the first and second plurality of hollow particles comprise glass bubbles. 
     
     
         10 . The method of  claim 8 , wherein the second span is less than 1.0. 
     
     
         11 . The method of  claim 8 , wherein a mean particle size of the second plurality of hollow particles ranges from about 10 micrometers to about 100 micrometers. 
     
     
         12 . The method of  claim 8 , wherein the binding segment has a formula:
   —Si(R 1 ) 3-x (R 2 ) x ;
   wherein x=0, 1, or 2;   wherein each group R 1  comprises independently OH −  or a hydrolyzable group from among halo, alkoxy, aryloxy, aralkyoxy, and acyloxy; and   wherein each group R 2  comprises independently a non-hydrolyzable group from among alkyl, aryl, and aralkyl.   
     
     
         13 . The method of  claim 8 , wherein the surface-modifying agent further comprises a linking segment, the linking segment comprising alkylene, arylene, or both, and optionally further comprising —NH— or alkyleneoxy, or both. 
     
     
         14 . The method of  claim 8 , wherein the reactive segment has a formula:
   —N(R 3 ) 2 , or salts thereof;
   wherein each group R 3  comprises independently hydrogen, alkyl, aryl, or aralkyl.   
     
     
         15 . A method for capturing an analyte the method comprising:
 providing a bioseparation composition comprising:   a plurality of hollow particles; and   a surface-modifying agent bonded to the hollow particles, wherein the surface-modifying agent comprises a binding segment and a reactive segment, wherein the binding segment comprises a silyl group, and wherein the reactive segment comprises a reactive nitrogen group;   wherein the plurality of hollow particles have an average density between about 0.05 and 0.4 g/ml; and   contacting the bioseparation composition with a solution comprising an analyte, wherein the surface-modifying agent is capable of coupling to the analyte.   
     
     
         16 . The method of  claim 15 , further comprising separating the bioseparation composition from the solution. 
     
     
         17 . The method of  claim 16 , wherein separating the bioseparation composition from the solution comprises allowing the bioseparation composition to float to an upper surface of the solution. 
     
     
         18 . The method of  claim 15 , wherein the hollow particles comprise glass bubbles. 
     
     
         19 . The method of  claim 15 , wherein a size distribution of the plurality of hollow particles has a span of less than 1.0.