Features of silicon– and titanium–polyethylene glycol precursors in sol–gel synthesis of new hydrogels

Abstract

The formation of organic/inorganic hydrogels based on silicon and titanium polyethylene glycolates, new biocompatible water-soluble precursors in sol-gel processing, was investigated. The influence of different factors on the gelation process, such as excess of PEG, water molar content, pH of medium, electrolyte additives, was investigated in comparison with silicon-and titanium-glycerol precursors. The specific features of gelation for each type of precursor were revealed. It has been determined that titanium polyethylene glycolates synthesized and used in the excess of PEG formed transparent polymeric hydrogels resistant to syneresis under certain conditions. The titanium polyethylene glycolates synthesized without excess of PEG formed turbid heterogeneous colloidal gels. In the case of silicon polyethylene glycolates the hydrogels obtained were polymeric. Dynamic light scattering was used to confirm the polymeric or colloidal type of gelation. The solid and liquid phases of polymeric silicon-and titanium-polyethylene glycol hydrogels were separated by exhaustive extraction. The solid phase was characterized by combined thermal analysis with simultaneous quadruple mass spectrometry, XRD, IR spectroscopy, and liquid phase-atomic emission spectroscopy. The structural features of polymeric gels were investigated by SEM and TEM methods. The cross-linking density of polymeric hydrogels was evaluated using Flory-Rehner theory based on the mechanical properties of swollen networks of flexible polymeric chains.

Biocompatible Silica-Polyethylene Glycol-Based Composites for Immobilization of Microbial Cells by Sol-Gel Synthesis

“…Two reagent systems including PEG differing in molecular mass (PEG3000 in SP EG -composite and PEG400 in STP EG -composite) were used as a polymeric matrix in the study for nanocomposite synthesis and cell immobilization. This was caused by different methodological approaches in the synthesis of silicon polyethylene glycol [ 66 , 68 , 70 ]. In addition, filler particles were synthesized from a TEOS:MTES mixture (15:85 v:v ratio) when the SPEG composite was produced.…”

“…Tetraethoxysilane (≥99.9%) and methyltriethoxysilane (MTES, ≥ 99.9%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Silicon polyethylene glycol (STP EG ) was synthesized according to the method described earlier [ 70 ]. Polyethylene glycol 3000 (PEG3000) from Ferak (Berlin, Germany).…”

“…Silicon polyethylene glycolates are used as precursors in the synthesis of organosilica composites for medical and biotechnological applications [ 69 , 70 , 71 , 72 ]. Their advantage over the conventional alkoxyl precursors based on monoatomic alcohols is that the hydrophilic polymers do not cause denaturation and/or precipitation of biological macromolecules.…”

“…Comparative analysis of the effectiveness of biocatalysts based on methylotrophic yeast Ogataea polymorpha VKM Y-2559 immobilized into organosilica materials of various compositions was studied in the present work. Immobilization of the microorganisms was carried out by one-stage sol-gel synthesis under basic catalytic conditions, and the following source reagents were used: the first variant (SP EG ) involved TEOS:MTES in a 15:85 volume:volume ratio and PEG3000 as a structure-forming agent, and the second variant (STP EG ) was composed of silicon tetrapolyethylene glycol synthesized from TEOS and PEG400 [ 70 ].…”

Биоактивные Кремнийорганические Гидрогели И Их Элемент-Модифицированные Производные Для Медицины И Ветеринарии

“…И.Я. Постовского УрО РАН был синтезирован с использованием золь-гель метода целый ряд фармакологически активных элементсодержащих гидрогелей, в том числе, нанокомпозитных, на основе полиолатов кремния, титана, цинка, борав качестве биосовместимых прекурсоров [1][2][3][4][5]. Были установлены общие закономерности и выявлены особенности зольгель процесса для каждого типа прекурсоров.…”