Type-A Gelatin-Based Hydrogel Infiltration and Degradation in Titanium Foams as a Potential Method for Localised Drug Delivery

Abstract

A gelatin-based hydrogel was infiltrated and degraded-released in two different titanium foams with porosities of 30 and 60 vol.% (Ti30 and Ti60 foams) and fabricated by the space holder technique to evaluate its potential to act as an innovative, alternative, and localised method to introduce both active pharmaceutical ingredients, such as antibiotics and non-steroidal anti-inflammatory drugs, and growth factors, such as morphogens, required after bone-tissue replacement surgeries. In addition, the kinetic behaviour was studied for both infiltration and degradation-release processes. A higher infiltration rate was observed in the Ti60 foam. The maximum infiltration hydrogel was achieved for the Ti30 and Ti60 foams after 120 min and 75 min, respectively. Further, both processes followed a Lucas-Washburn theoretical behaviour, typical for the infiltration of a fluid by capillarity in porous channels. Regarding the subsequent degradation-release process, both systems showed similar exponential degradation performance, with the full release from Ti60 foam (80 min), versus 45 min for Ti30, due to the greater interconnected porosity open to the surface of the Ti60 foam in comparison with the Ti30 foam. In addition, the optimal biocompatibility of the hydrogel was confirmed, with the total absence of cytotoxicity and the promotion of cell growth in the fibroblast cells evaluated.

Chitosan–Type-A-Gelatin Hydrogels Used as Potential Platforms in Tissue Engineering for Drug Delivery

“…These differences highlight the better mechanical resistance of hydrogels that have a small amount of chitosan due to the necessity of a material that can withstand mechanical stress during the cell growth and proliferation stage. Finally, highlighted are the similarities between the profile of the frequency curve of the unitary type A gelatin-based hydrogel obtained at 5 • C and the one obtained in research done by Mehdi-Sefiani, H. et al [32]. On the other hand, we found similarities between the frequency curves obtained for binary hydrogels made by chitosan and the collagen studied by Sánchez-Cid et al [40].…”

“…First, a big difference between the structure of the chitosan-based hydrogel (Figure 6A,A ′ ) and the type A gelatin-based hydrogel (Figure 6E,E ′ ) can be noted. The chitosan-based hydrogel has an ordered sponge network structure consisting of small spheres (aggregates) linked together, while the structure of the type A gelatin-based hydrogel is characterized by the presence of porous grains as shown in other studies [32,43,44]. However, comparing the porosity of both systems can highlight the lower porosity in the structure of chitosanbased hydrogels, which corroborates the dates obtained in the rheology about its greater structuring and, consequently, its solid characteristic.…”

“…Gelatin is a natural polymer obtained through hydrolytic degradation of type I collagen. This biopolymer has been widely used in biomedical applications due to its high biodegradability, biocompatibility, non-toxicity, non-immunogenicity, and highwater absorption [18,[30][31][32]. Notably, these properties render gelatin an excellent candidate for drug-delivery vehicles [31].…”

“…There are two types of gelatins, type A and type B gelatin, which are obtained by an acid-treated and alkali-treated process [31]. In particular, type A gelatin (G) has demonstrated great biocompatibility and the ability to form hydrogels [32]. According to the literature, gelatin hydrogels are a promising choice for delivering therapeutic or pharmaceutical compounds, thanks to their distinct properties.…”

Influence of Natural Crosslinkers on Chitosan Hydrogels for Potential Biomedical Applications

“…All of them were seeded at 10 5 cells per well in Nunc flat-bottomed 96-well plates (ThermoFisher Scientific, USA) following the protocol described in the previous studies. [49][50][51] Cytotoxicity was determined by fluorescence in a CLARIOstar (BMG LABTECH, Germany). Each hydrogel concentration (wt%) was measured in triplicate and the tests were repeated thrice independently.…”