In this report we show that drug incubation temperature, methods used for removing surfactant templates from mesoporous materials and solvents used for placing surface organic functional groups on the materials can improve or affect the adsorption capacity and drug release properties of potentially useful nanoporous silica and organosilica as drug delivery vehicles. This is demonstrated by investigating the adsorption and release properties toward rhodamine 6G (R6G) and an anticancer drug, cisplatin, of various solvent-extracted and calcined mesoporous silicas (MCM-41 and SBA-15), organic-functionalized mesoporous silicas containing terminal organoamine, organothiol and vinyl groups, and bridging organic-functionalized ethane periodic mesoporous organosilica (ethane PMO) under various conditions. Two different solvents, isopropanol and toluene, were used to graft the terminal organic groups from their corresponding organosilanes, producing materials with slightly different adsorption and release properties. The adsorption capacities of the organic-functionalized mesoporous silicas that were prepared from a well solvent-extracted MCM-41 increased significantly as the temperature was raised from room temperature to 50 and 75 °C. Furthermore, samples with a higher percent adsorption of R6G and cisplatin also showed higher overall percent release of the adsorbed R6G or cisplatin molecules in a simulated body fluid (SBF) solution. Interestingly, the ethane PMO also showed significantly higher adsorption capacity for both R6G and cisplatin than the control samples, MCM-41 or SBA-15. Raising the temperature improved the adsorption capacity of ethane PMO, for both R6G and cisplatin. The method used to remove the surfactant templates from the parent mesostructured materials was also found to affect the materials’ adsorption properties.

One feature of colloidal arrays that make them of interest to materials scientists is the unique optical properties a periodic dielectric array with long range order can offer. Two approaches to assemble colloidal particles have been pursued, one approach involves the steric packing of hard spheres, while the other approach employs the electrostatic repulsion of the particles to procure order. A unique feature of electrostatically stabilized colloidal particles is that the interparticle distance can be varied post-assembly, [1,2] resulting in a level of optical tuning. These latter systems are generally assembled in a high-dielectric liquid medium and therefore prone to disordering with a number of stimuli. The self-assembly of the particles into a crystalline colloidal array is sensitive to the charge characteristics of the particles, as well as the environment in which assembly will occur. A number of stringent requirements must be met to insure a crystal with a reduced level of disorder; slight deviations in a range of environmental conditions can result in a poor level of organization, or the complete lack of order.[3]Asher and co-workers [4] pioneered a hydrogel encapsulation route for these electrostatically-based systems that stabilized the particles once ordered and allowed for a wider field of application. The majority of these systems are composed of simple dielectrics, such as poly(styrene), poly(methyl methacrylate), or silica, since these materials produce colloidal particles that readily self-assemble when in the appropriate environment. Nonetheless, the modification of the particles post-hydrogel encapsulation to alter or enhance the optical properties of the array poses a challenge. Although there have been demonstrated techniques to introduce various components into the interstitial regions of the ordered particles after the hydrogel film formation, [5] procedures that chemically modify the core colloids within the hydrogel film are scarce.In the current effort, we propose a general strategy for the preparation of well-defined and regioselectively functionalized ordered colloidal particles. This is achieved with the functionalization of hydrogel-stabilized colloidal arrays through a "click" chemistry approach. Click transformations, [6][7][8] specifically the copper(I)-catalyzed variant of the Huisgen 1,3-dipolar cycloaddition between azides and terminal alkynes to form 1,2,3-triazoles, [9][10][11][12] have found utility in the synthesis and/or functionalization of a range of systems, for example: polymers; [13][14][15][16][17][18] small molecules; [19][20][21][22] biomolecules; [23][24][25][26][27][28][29][30][31][32] hydrogels; [33] core-shell nanoparticles; [34,35] and surfaces. [36][37][38][39] The stability of azides and alkynes in aqueous solutions enables these functionalities to act as inert chemical handles for a range of selective chemical reactions and offers a facile route to modify ordered colloidal particles post-hydrogel stabilization. This general strategy is demonstrated through ...

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Photonic crystals based on electrostatically‐stabilized colloidal arrays dispersed in a liquid medium are of interest to materials scientists partly because of the optical tuning afforded to theses systems with a variation in interparticle distance. On p. 3507, Stephen Foulger and co‐workers from Clemson University, USA report on a general strategy for the preparation of well‐defined and regioselectively functionalized ordered colloidal particles through the exploitation of “click” chemistry. Click transformations have found utility in the synthesis and/or functionalization of a range of systems. In addition, the solvochromic tuning of the ordered arrays is employed to modify the emission spectra of the surface‐attached photoluminescent dyes.