Clindamycin-Loaded Halloysite Nanotubes as the Antibacterial Component of Composite Hydrogel for Bone Repair

Abstract

A new drug delivery system consisting of clindamycin phosphate entrapped in acid-etched halloysite nanotubes was successfully prepared and characterized. It was then used as an antibacterial component of the multicomponent hydrogel designed as a material for bone regeneration. First, halloysite (HNT) was etched and clindamycin phosphate (CP) was entrapped in both raw and modified nanotubes, resulting in HNT-CP and EHNT-CP systems. They were characterized using SEM, TEM, TGA and FTIR; the entrapment efficiency and release of CP from both systems were also studied. EHNT-CP was then used as an antibacterial component of the two hydrogels composed of alginate, collagen and β-TCP. The hydrogels were prepared using different crosslinking procedures but had the same composition. The morphology, porosity, degradation rate, CP release profile, cytocompatibility, antibacterial activity and ability to induce biomineralization were studied for both materials. The hydrogel obtained by a chemical crosslinking with EDC followed by the physical crosslinking with calcium ions had better properties and was shown to have potential as a bone repair material.

Functionalized Halloysite Nanotubes as Potential Drug Carriers

“…The loading efficiency ( LE ) of halloysite was calculated according to Formula (1) [ 40 ]: LE (%) = ( M t / M 0 )∙100 where: M t —mass of the drug, M 0 —total mass of the powder sample after drug loading.…”

Recent Advances of Halloysite Nanotubes in Biomedical Applications

“…Wang [76] Ofloxacin (OFL) Machowska [78] Clindamycin ↑Entrapment efficiency; ↑Extended release; Drug antibacterial effect E-HNT HNT is etched with acetic acid first and then entrap the clindamycin phosphate.…”

“…In a similar vein, clindamycin, a member of the lincosamide antibiotic class, is effective against infections due to its ability to impede bacterial protein synthesis. [78] Within this tapestry of exploration, Sepahi's group [73] embarked on an insightful trajectory, harnessing HNTs etched through sulfuric acid as a vessel for amoxicillin delivery. The nuanced modifications introduced in this endeavor bore fruit, manifesting in a controlled drug release regimen wherein the initial burst was mitigated and supplanted by sustained release kinetics spanning 168 h. This orchestration precipitated a manifold enhancement: an amplified loading capacity, bolstered by a 4% augmentation, and a parallel improvement in the drug delivery efficiency.…”

“…In a similar vein, clindamycin, a member of the lincosamide antibiotic class, is effective against infections due to its ability to impede bacterial protein synthesis. [ 78 ]…”

“…Echoing this, Machowska's group harnessed the power of acetic acid‐etched HNTs, articulating their efficacy in enhancing entrapment efficiency and fostering extended release dynamics of clindamycin. [ 78 ] The investigation discerned a distinct advantage conferred by the etched HNTs, as compared to their pristine counterparts. Importantly, this augmentation in efficiency materialized as a tangible superiority within the EHNT‐CP configuration, encapsulated within the H1‐EDC/CaCl 2 hydrogel.…”