10.1021/am4059217.s001 Abhishek Bang Abhishek Bang Anand G. Sadekar Anand G. Sadekar Clayton Buback Clayton Buback Brice Curtin Brice Curtin Selin Acar Selin Acar Damir Kolasinac Damir Kolasinac Wei Yin Wei Yin David A. Rubenstein David A. Rubenstein Hongbing Lu Hongbing Lu Nicholas Leventis Nicholas Leventis Chariklia Sotiriou-Leventis Chariklia Sotiriou-Leventis Evaluation of Dysprosia Aerogels as Drug Delivery Systems: A Comparative Study with Random and Ordered Mesoporous Silicas American Chemical Society 2014 7 nm tubes Drug release data Mesoporous SilicasBiocompatible dysprosia aerogels Drug Delivery Systems drug uptake dysprosia aerogels drug release rate 2014-04-09 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Evaluation_of_Dysprosia_Aerogels_as_Drug_Delivery_Systems_A_Comparative_Study_with_Random_and_Ordered_Mesoporous_Silicas/2306911 Biocompatible dysprosia aerogels were synthesized from DyCl<sub>3</sub>·6H<sub>2</sub>O and were reinforced mechanically with a conformal nano-thin-polyurea coating applied over their skeletal framework. The random mesoporous space of dysprosia aerogels was filled up to about 30% v/v with paracetamol, indomethacin, or insulin, and the drug release rate was monitored spectrophotometrically in phosphate buffer (pH = 7.4) or 0.1 M aqueous HCl. The drug uptake and release study was conducted comparatively with polyurea-crosslinked random silica aerogels, as well as with as-prepared (native) and polyurea-crosslinked mesoporous silica perforated with ordered 7 nm tubes in hexagonal packing. Drug uptake from random nanostructures (silica or dysprosia) was higher (30–35% w/w) and the release rate was slower (typically >20 h) relative to ordered silica (19–21% w/w, <1.5 h, respectively). Drug release data from dysprosia aerogels were fitted with a flux equation consisting of three additive terms that correspond to drug stored successively in three hierarchical pore sites on the skeletal framework. The high drug uptake and slow release from dysprosia aerogels, in combination with their low toxicity, strong paramagnetism, and the possibility for neutron activation render those materials attractive multifunctional vehicles for site-specific drug delivery.