Bifunctional Nanomaterials for Enhanced Cell Proliferation and for the Reduction of Bacterial Bioluminescence/Fitness

Abstract

This study describes the synthesis of bifunctional nanomaterials that can both inhibit bacterial bioluminescence, an indicator for the bacterial fitness, and, simultaneously, improve the proliferation of eukaryotic cells, a property that is desired for biomedical devices such as implants. To prepare this functional nanomaterial, the pores of the periodic mesoporous organosilica (PMO) nanocontainers are first functionalized with dexamethasone (Dex), which has anti‐inflammatory and cell proliferation properties. Then, the external surface of the PMO is functionalized with the antibacterial and cell adhesive bipolymer poly‐d‐lysine (PDL). The results show that cofunctionalization of the PMO surfaces with both Dex and PDL have beneficial additive and/or synergistic effects on cell proliferation and bacterial bioluminescence inhibition.

3D printed step‐gradient composite hydrogels for directed migration and osteogenic differentiation of human bone marrow‐derived mesenchymal stem cells

“…The external and internal surfaces of periodic mesoporous organosilicas (PMO) were functionalized with poly‐ d ‐lysine (PDL) and dexamethasone (Dex), respectively, as we have previously described and characterized, [ 42 ] to obtain bifunctional PMO ( Dex PMO‐PDL) (Figure 1A). PDL and Dex were used in this study due to their beneficial effects on cells.…”

“…Dex is a bone‐growth steroid used as an anti‐inflammatory drug and can also regulate cellular proliferation. [ 42,44 ] Further, Dex shows a dose‐dependent beneficial impact on the differentiation of MSC into osteogenic lineages. [ 45 ] Therefore, we expected that the biodegradable PDL would enhance cell adhesion and, at the same time, control the release kinetics of Dex from the PMO.…”

“…The prepared Dex PMO‐PDL, GA5, GA10, and GA10‐P hydrogels/scaffolds were analyzed as we have described previously (see the supporting information). [ 42 ] SEM images showed that the 3D printed GA5, GA10, and GA10‐P scaffolds had similar interconnected porous networks with irregular pore sizes (Figure 1K‐M). The GA10‐P scaffolds showed a higher porosity (%) (Table S1), a higher swelling capacity (Table S2), less degradation (Table S3), and a higher viscosity, compressive, storage ( G′ ) and loss ( G″ ) modulus and higher resistance to streching (Figure 2) than the GA5 and GA10 scaffolds due to the enforcement of the GelMA/Alg network by hydrophilic Dex PMO‐PDL.…”

“…We examined the release kinetics of Dex from GA10‐P and Dex PMO‐PDL at pH 7.4 and 6.0 (where this lower pH value reflects the pH in a tumor or an inflammatory tissue environment) [ 39–42 ] at different time periods (e.g., from 3 min to 7 days) (Figure 3). Our results showed that the Dex release from the GA10‐P scaffold at pH 7.4 and 6.0 was prolonged and pH dependent.…”

Step‐Gradient Composite Hydrogels for Local Drug Delivery and Directed Cell Migration

“…Thus, PDL prevented the cells from interacting with high concentrations of free Dex, limiting Dex's side effects on cell viability. [ 35 ]…”