Designing of Dextrin Gated Porous Alumina-Silica base Nanostructures as Drug Carrier

Abstract

The designing and development of highly efficient nano-materials is currently exploited research for applications in the fields of environment and pharmaceuticals (nanomedicine). This research is an attempt to synthesize economical, biocompatible and eco-friendly (nontoxic) functional hybrids based on silica, alumina and alumina-silicate. The main objective of the study is the application of synthesized materials as potential adsorbents for the removal of toxic metals (Pb, Hg) from an aqueous medium. Secondly, the loading of drug (cisplatin) and designing with dextrin for development as carriers for controlled drug delivery. For this purpose, a quick, simple, one-pot method is adopted for the synthesis of 8 series of materials classified as un-loaded base (Si, Al, AlSi), loaded base (L-Si, L-Al, LAlSi), silica functionalized (SiTi, SiV, SiTiV) loaded silica (L-SiTi, L-SiV, L-SiTiV), alumina functionalized (AlTi, AlV, AlTiV) loaded alumina (L-AlTi, L-AlV, L-AlTiV), aluminasilicate functionalized (AlSiTi, AlSiV, AlSiTiV) and loaded alumina-silicate (L-AlSiTi, LAlSiV, L-AlSiTiV) hybrids. A material of each class is completely characterized using standard techniques and protocols. The successful functionalization of base materials, loading of cisplatin (at 1600cm-1) and capping with β-cyclodextrin (at 1100cm-1) is clearly witnessed in FTIR spectra. The characteristic morphology varying from spherical to elongated structures are scanned by SEM. XPS indicates that cisplatin is positioned as Pt(4f), whereas C-C and C=C bonding is for grafting. BET isotherm suggests a significant increase in surface area of both unloaded and loaded materials proposing excellent potential for adsorption. Further, silica-based hybrids in comparison to alumina reveal significant drug release due to a good binding affinity of the former. The regeneration capacity of these materials also offers direct acquiescence to 3R (reuse, reduce and recycle) principle. The research concludes and recommends the application of functionalized hybrid as agents to environmental remediation. Another important output of this research is the potency of materials as a carrier for control release of cisplatin (anti-cancerous drug) towards targeted organ. Dialysis membrane experiments were carried out for drug release whereas batch adsorption experiment was performed to determine the adsorption behaviour. The drug release findings suggest that base silica shows 44%, encapsulation efficiency whereas, for silica functionalized hybrids (L-SiTi, L-SiV and L-SiTiV), it is 24%, 89% and 14%, respectively. Silica alumina x

and alumina-silicate functionalized hybrids reveal (13%-81%), (6%-31%) and (19%-49%) encapsulation efficiency respectively. The adsorption results suggest increase in uptake of mercury ions with the increase in concentration in following sequence (Si, Al, AlSi, SiTi, SiV, SiTiV, AlTi, and AlV AlTiV).It is observed that silica, alumina and alumina-silicate functionalized hybrids (Si, Al, AlSi-Ti and AlSiV) show good lead removal at initial induced concentration. Likely Si-Ti, SiV, SiTiV, AlTi, AlV AlTiV, AlSi and AlSiTiV show increase in uptake of lead ions with the increase in the metal ions concentration.