title: Mesochanneled hierarchically porous aluminosiloxane aerogel microspheres as a stable support for pH-responsive controlled drug release.
abstract: The molecular-scale self-assembly of a 3D aluminosiloxane (Al-O-Si) hybrid gel network was successfully performed via the cocondensation of hydrolyzed alumina (AlOOH) and (3-aminopropyl)trimethoxysilane (APS). It was transformed into a microspherical aerogel framework of Al-O-Si containing mesochannels with tunable hierarchically bimodal meso/macroporosities by a subcritical drying technique. Good homogeneity of AlOOH and APS brought during the synthesis guaranteed a uniform distribution of two metal oxides in a single body. A systematic characterization of the aerogel support was carried out using FTIR, SEM, TEM, nitrogen adsorption/desorption analysis, WAXS, SAXS, and ξ-potential measurement in order to explore the material for drug uptake and release. The drug loading and release capacity and chemical stability of an aluminosiloxane aerogel were studied using two nonsteroidal antiinflammatory drugs, ibuprofen and aspirin. A comprehensive evaluation of the aluminosiloxane aerogel with ordered mesoporous MCM-41 was also performed. Aerogel supports showed a high drug loading capacity and a pH-responsive controlled-release property compared to MCM-41. Meanwhile, kinetic modeling studies indicate that the drug releases with a zero-order profile following the Korsmeyer-Peppas model. The biocompatibility of aluminosiloxane aerogels was established via ex vivo and in vivo studies. We also outline the use of aluminosiloxane aerogel as a support for a possible 3D matrix for an osteoconductive structure for bone tissue engineering.
authors.affiliation: Functional Materials Section, Materials Science and Technology Division, Council of Scientific and Industrial Research, National Institute for Interdisciplinary Science and Technology (CSIR-NIIST) Thiruvananthapuram, 695019 Kerala, India.
authors.forename: Linsha
authors.initials: L
authors.lastname: Vazhayal
authors.forename: Sindhoor
authors.initials: S
authors.lastname: Talasila
authors.forename: Peer Mohamed
authors.initials: PM
authors.lastname: Abdul Azeez
authors.forename: Ananthakumar
authors.initials: A
authors.lastname: Solaiappan
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D002460:Cell Line; D003692:Delayed-Action Preparations / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007052:Ibuprofen; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D016062:Porosity; D051381:Rats; D012822:Silicon Dioxide / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D017607:Aluminum Compounds; D003692:Delayed-Action Preparations; D005782:Gels; C509968:MCM-41; D012833:Siloxanes; D012822:Silicon Dioxide; D001241:Aspirin; D007052:Ibuprofen
keywords: aerogel microspheres; biocompatibility; controlled drug-delivery system; hierarchically structured bimodal porosities; pH-responsive; sol−gel synthesis