Zn‐Loaded SBA‐1 and SBA‐15 Molecular Sieves for Combined Antimicrobial and Osteogenic Activity

Abstract

possibilities [1] in various technologically advanced fields, including sensing, [2] energy, [3] catalysis, [4] and biomedical applications. [5] Among these, biomedical applications of mesoporous silica nanoparticles (MSNs) have gained momentum in the past decade with their diverse range of applications in drug delivery systems, bioimaging, biosensors, and biomarker or gene transfection carriers owing to their unique properties such as high surface area and large pore volume, tunable morphology and pore size, affordable surface modification and high bio-compatibility. [6] Recently, MSNs have been explored as artificial substitutes for bone tissue regeneration and remodeling. [7] The initial results gave a promising outlook in which MSNs gradually decomposed in simulated body fluids (SBF) at 37 °C[8] and promoted osteoinduction, osteoconduction, and osteointegration similar to the popular scaffold materials such as bioactive glasses, carbon-based materials, metals/ ceramic composites. [7a,9] Additionally, owing to their ordered porous structure, MSNs were used to load various drugs and antibiotics for bone disease treatment (bisphosphonate, oxytocin, ciprofloxacin), the antimicrobial effect, [10] or were supplemented with factors for supporting bone regeneration (metformin, calcium sulfate). [11] Mesoporous silica-based materials are currently being explored as a new type of bioscaffold for bone regeneration applications. Zinc(Zn) ion incorporation is shown to play an important role in promoting bone regeneration and also providing antimicrobial activity to the scaffold materials. In this work, the role of pore size, geometry, and ordered structure on the Zn loading and release performance of two different mesoporous silica, SBA-1 and SBA-15, are compared. Zn loading is varied from 2.5 to 10 wt% for both samples, and its effect on the antibacterial and osteogenic activity is evaluated. Zn loading up to 10 wt% has a negligible effect on the morphology and textural properties of the mesoporous silica samples. The inductively coupled plasma mass spectrometry (ICP-MS) analysis reveals that SBA-15 exhibits significantly higher Zn release in Luria-Bertani (LB) broth as compared to SBA-1 that is reflected in the higher antibacterial activity of SBA-15 against both gram-positive and gram-negative bacteria. Various assays show that 5 wt% Zn loading is sufficient to produce both bactericidal and inhibitory effects on bacterial cells. The 5 wt% Zn-loaded samples induce osteogenic differentiation ofavianized bone marow-derived stromal cells (TVA-BMSCs) though SBA-15 samples show better compatibility compared to SBA-1, suggesting that Zn incorporation can produce sufficient antibacterial effect and osteogenic differentiation of TVA-BMSCs.

Advances in Nanomaterials and Composites Based on Mesoporous Materials as Antimicrobial Agents: Relevant Applications in Human Health

“…Biocompatibility was assessed using MC3T3-E1 cells, revealing that Zn/MBG fosters cell proliferation and exhibits favorable cytocompatibility. Another author used Zn-Loaded SBA-1 and SBA-15 for bone regeneration [81]. A comparison was made regarding the influence of geometry, pore size, Other authors studied Zn(II) species as antimicrobial agents, as in [80], who modified the surface of a 3D printed titanium scaffold with Zn-MBG to prevent implant-related infections.…”

“…Biocompatibility was assessed using MC3T3-E1 cells, revealing that Zn/MBG fosters cell proliferation and exhibits favorable cytocompatibility. Another author used Zn-Loaded SBA-1 and SBA-15 for bone regeneration [81]. A comparison was made regarding the influence of geometry, pore size, and ordered structure of SBA-1 and SBA-15 on zinc loading and release performance.…”

“…Bone formation [77] MBGNs/copper ions S. aureus Antibacterial [78] Phosphate-based mesoporous glasses/ Cu ions S. aureus, E. coli Bioabsorbable materials [79] Zn-MBG S. aureus, E. coli Implants-associated infections [80] Zn/SBA-1/SBA-15 E. coli, B. subtilis Bone regeneration [81] Tricalcium silicate/MBGNs/Li S. aureus, E. coli Biomedical applications [82] MBGNs/Ce-Co S. aureus Wound healing [83] Na and colleagues presented an approach against antimicrobial infections by combining antibiotics with photothermal therapy using multifunctional nanomaterials [84]. In this study, the inherent photothermal efficiency of two-dimensional rhenium disulfide (ReS 2 ) nanosheets was heightened by coating them on mesoporous silica nanoparticles (MSNs) to create a highly efficient light-responsive nanomaterial with controlled-release drug delivery capabilities, known as MSN-ReS 2 .…”