Mesoporous calcium silicate compositions and methods for synthesis of mesoporous calcium silicate for controlled release of bioactive agents
First Claim
1. A biocompatible composition for controlling release of a bioactive agent, comprising:
- a plurality of calcium silicate (CaSiO3) particles each comprising;
(i) a crystalline interior portion having a network of covalently bonded silica (SiO2) interrupted and modified by a plurality of calcium cations (Ca2+); and
(ii) an exterior surface having a layer of silica gel and having a lower calcium cation concentration than the interior portion, wherein the exterior surface is mesoporous;
a bioactive agent deposited onto the exterior surface or incorporated into the interior portion of each of the calcium silicate particles, wherein the bioactive agent is bonded to the calcium silicate particles in vitro; and
a calcium-based ceramic, and wherein the plurality of calcium silicate particles are packed into the calcium-based ceramic.
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Abstract
Mesoporous calcium silicate compositions for controlled release of bioactive agents and methods for producing such compositions are disclosed herein. In one embodiment, mesoporous calcium silicate is synthesized by acid modification of wollastonite particles using hydrochloric acid. A hydrated silica gel layer having abundant Si—OH functional groups can be formed on the surface of wollastonite after acid modification. Bruhauer-Emmett-Teller (BET) surface area increased significantly due to acid modification and, in one arrangement, reached over 350 m2/g. Acid modified mesoporous calcium silicate compositions show a higher ability to adsorb protein compared to unmodified particles and demonstrate controlled release kinetics of these proteins.
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Citations
19 Claims
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1. A biocompatible composition for controlling release of a bioactive agent, comprising:
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a plurality of calcium silicate (CaSiO3) particles each comprising; (i) a crystalline interior portion having a network of covalently bonded silica (SiO2) interrupted and modified by a plurality of calcium cations (Ca2+); and (ii) an exterior surface having a layer of silica gel and having a lower calcium cation concentration than the interior portion, wherein the exterior surface is mesoporous; a bioactive agent deposited onto the exterior surface or incorporated into the interior portion of each of the calcium silicate particles, wherein the bioactive agent is bonded to the calcium silicate particles in vitro; and a calcium-based ceramic, and wherein the plurality of calcium silicate particles are packed into the calcium-based ceramic. - View Dependent Claims (2, 3, 4, 5)
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6. A biocompatible composition for controlling release of a bioactive agent, comprising:
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a plurality of calcium silicate (CaSiO3) particles each comprising; (i) a crystalline interior portion having a network of covalently bonded silica (SiO2) interrupted and modified by a plurality of calcium cations (Ca2+); and (ii) an exterior surface having a layer of silica gel and having a lower calcium cation concentration than the interior portion; a bioactive agent deposited onto the exterior surface or incorporated into the interior portion of each of the calcium silicate particles, wherein the bioactive agent is bonded to the calcium silicate particles in vitro and includes at least one of a protein, a polypeptide, a growth factor, a morphogen, an antibiotic, an antimicrobial agent, an osteoporotic drug, or a vitamin; and a calcium-based ceramic mixed with the plurality of calcium silicate particles, the calcium-based ceramic containing calcium phosphates or calcium sulfates. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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14. A biocompatible composition for controlled release of a bioactive agent, the composition comprising:
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a plurality of calcium silicate (CaSiO3) particles individually including; a crystalline interior portion having a network of covalently bonded silica (SiO2) interrupted and modified by a plurality of calcium cations (Ca2+); and an exterior surface proximate the interior portion, the exterior surface having a layer of hydrated silica gel with a plurality of Si—
OH functional groups;a bioactive agent deposited onto the exterior surface or incorporated into the interior portion of the individual calcium silicate particles in vitro, wherein the bioactive agent includes at least one of a protein, a polypeptide, a growth factor, a morphogen, an antibiotic, an antimicrobial agent, an osteoporotic drug, or a vitamin; and a calcium-based ceramic mixed with the plurality of calcium silicate particles, the calcium-based ceramic containing calcium phosphates or calcium sulfates, at least one of the calcium silicate particles or the calcium-based ceramic having a dopant containing one or more of Zn2+, Mg2+, Si2+, Na+, K+, Sr2+, Cu2+, Fe3+/Fe2+, Ag+, Ti4+, CO32−
, F−
, MgO, ZnO, NaF, KF, FeO/Fe2O3, SrO, CuO, SiO2, TiO2, Ag2O, or CaCO3, wherein the dopant in the at least one of the calcium silicate particles or the calcium-based ceramic presents in an amount between 0 wt % and about 10 wt %. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification