صدیقه هاشم نیا

Since use of biocompatible large pore mesoporous silica compounds with appropriate particle size, pore volume, pore diameter and ultimately high drug loading capacity is an important and challenging issue for targeted delivery and transfer of large pharmaceutical molecules such as proteins, hence, we have presented some efficient methods for their synthesis by increasing the pore diameter and volume. In the previous reported approach, tetraethyl orthosilicate was just used as a silica source. In this study, TMB, known as a pore expanded, has been used to create large pores in silica mesoporous nanoparticles. Also, different extracts of ammonium nitrate, calcium chloride and aluminum nitrate have been used for extraction of micelle template and the results of these methods have been compared. Brunauer-Emmett-Teller (BET)analysis shows, by adding organic solvent cyclohexane to aqueous solution of tetraethyl orthosilicate, the pore volume and size have been significantly improved, which eventually leads to an increase in pore diameter (7.35 nm) as well as an increase in pore volume,)/97(???? 3/ ???? , of these nanoparticles. Also, addition of 1,3,5-trimethylbenzene (TMB) besides to the aqueous solution of cyclohexane in aqueous tetraethyl ortho silicate solution, further increases the pore diameter (9.04 nm) as well as the pore volume )1/25(????3/???? . Furthermore, the effect of ???? 3, ???? 2 and ???? 4 on increasing the diameter and volume of the pores during the extraction process have been also investigated. In this case, BET analysis shows that the use of aluminum nitrate results in the highest pore volume (in the presence of TMB equal to 2.70 ???? 3 /???? and in the absence of TMB equal to 2.04 ???? 3 /???? ) compared to the pore volume in the calcium chloride extraction method (in the presence of TMB equals 2/11 ????3 /???? and in the absence of TMB equals 2/00 ???? 3/???? ) and extraction with ammonium nitrate (in the presence of TMB equal to 1.25 ???? 3 /????