Tailorable low temperature silica-gelatin biomaterials for drug delivery

• Published in: Ceramics international Vol. 48; no. 19; pp. 28659 - 28668
• Main Authors: Rodríguez-González, Raquel, Bosch-Rué, Elia, Díez-Tercero, Leire, Delgado, Luis M., Pérez, Román A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2022
• Subjects: Drug delivery; Gelatin; GPTMS; Hybrid; Silica; Sol-gel; Tissue regeneration; Gelatin; Sol-gel; Hybrid; Drug delivery; Tissue regeneration; Silica; GPTMS
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2022.06.180

Sol-gel silica-based hybrids combine an inorganic compound, silica, with an organic one to tune its properties for tissue regeneration. These hybrid materials can be produced at low temperature, which allow to encapsulate and release bioactive molecules, acting as a drug delivery system and enhancing tissue regeneration. In this study, tetraethyl orthosilicate (TEOS) has been combined with gelatin, which was cross-linked with 3-Glycidyloxypropyl)trimethoxysilane (GPTMS). Different factors during silica preparation can influence the physicochemical properties of the hybrids; therefore, different H2O/TEOS molar proportions and different volume ratios of TEOS:GPTMS and gelatin:sol were explored in the silica-gelatin hybrid preparation. The properties of the materials were assessed, obtaining the influence of each factor on swelling, degradation, mechanical properties and encapsulated molecule release rate. Higher amount of water in the reaction decreased the degradation rate and mechanical properties of the hybrid, while reducing the water uptake. In the case of the TEOS:GPTMS volume ratio, a higher amount of cross-linker slightly decreased the water uptake and the degradation rate, improving the mechanical properties. Finally, for the gelatin:sol volume ratio, as the amount of polymer increases, the water uptake, degradation rate and mechanical properties were higher. Lastly, a model molecule, doxycycline, was also encapsulated within the hybrids and release over 21 days, demonstrating the encapsulation and release capacity of drugs without limiting their stability. The release rate showed a similar tendency as degradation, being faster as the water and gelatin amounts increased and slower as the cross-linker concentration raised. These results demonstrate that the different parameters of the silica-gelatin hybrids during preparation can be adjusted to tune the properties and drug release rates, making them promising biomaterials to use as drug delivery scaffolds for tissue regeneration. [Display omitted] •Tailorable sol-gel silica-gelatin hybrids were developed, changing three different parameters of the reaction.•The water uptake was increased for the highest ratios in all factors.•The degradation was only influenced by the TEOS:GPTMS and gelatin:sol volume ratios.•The mechanical properties were mainly influenced by the amount of gelatin, increasing the toughness as the gelatin increases.•The mild conditions of the reaction allowed for the encapsulation and release of doxycycline without affecting functionality.