Dexamethasone-Loaded Bioactive Coatings on Medical Grade Stainless Steel Promote Osteointegration

Abstract

In this study, a multilayer bioactive coating based on carboxymethyl cellulose (CMC) and dexamethasone (DEX) was prepared on medical-grade stainless steel (AISI 316LVM). Its aim was the controlled drug delivery of the incorporated anti‑inflammatory drug, which at the same time promotes osteogenic differentiation of mesenchymal stem cells. Due to DEX’s limited solubility in physiological fluids, which limits the loading capacity of coatings, it was further combined with β-cyclodextrin to increase its concentration in the bioactive coating. Controlled release of DEX from the multilayer coating was achieved in four steps: a “burst”, i.e., very fast, release step (in an immersion interval of 0–10 min), a fast release step (10–30 min), a slow-release step (60–360 min), and a plateau step (360–4320 min), following a zero-order release or Higuchi model release mechanism. Successful layer-by-layer coating formation was confirmed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). It was shown that the application of the coating significantly increases the hydrophilic character of AISI 316LVM, and also significantly increases the surface roughness, which is known to promote cell growth. In addition, electrochemical measurements demonstrated that the coating application does not increase the susceptibility of medical-grade stainless steel to corrosion. In vitro cell testing using all cell types with which such coatings come into contact in the body (osteoblasts, chondrocytes, and mesenchymal stem cells (MSCs)) showed very good biocompatibility towards all of the mentioned cells. It further confirmed that the coatings promoted MSCs osteogenic differentiation, which is the desired mode of action for orthopedic implants.

Mesenchymal Stem Cells Isolated from Paediatric Paravertebral Adipose Tissue Show Strong Osteogenic Potential

“…Specific staining revealed that the cells were positive for CD29, CD44, CD73, CD90, CD105 and CD166 and negative for CD14, CD31, CD34 and CD45 (adipose-derived mesenchymal stem cells; normal, human (ATCC PCS-500-011)). The cell line has been used to date for various research applications, including adipose tissue regeneration [ 21 ], osteointegration in bioactive coatings [ 22 ], chondrogenesis [ 23 ] and neurogenesis [ 24 ].…”

Analytical Techniques for the Characterization of Bioactive Coatings for Orthopaedic Implants

“…Using ATR-FTIR, the bioactivity of prepared coatings was confirmed by signals related to PO 4 3 − , indicating apatite, in a study by De Santis et al [ 69 ] after ceria was combined with TNTs and soaked in SBF at 37 °C for 8 days. The technique can also offer information on whether the drug was successfully incorporated into the bioactive coatings and whether it was physically or chemically bound to the coatings [ 32 , 34 , 85 , 86 , 87 , 88 , 89 , 90 ]. In a study by Kiran et al [ 87 ], coatings of poly(ε-caprolactone) (PCL) nanofibers loaded with HA and rifampicin were electrospun on a Ti substrate.…”

Mussel-Inspired Polydopamine-Based Multilayered Coatings for Enhanced Bone Formation

“…Drugs for immunomodulation include dexamethasone ( Tejido-Rastrilla et al, 2018 ; Xu et al, 2019 ; Rozanc et al, 2021 ; Xiao et al, 2021 ), chondroitin sulfate ( Li Y.-M. et al, 2019 ), salidroside ( Yi et al, 2022 ), aspirin ( Wei et al, 2020 ) and so on. Among different antiinflammation drugs, dexamethasone can actually alleviate all levels of inflammation and is commonly used to treat various inflammatory diseases ( Rozanc et al, 2021 ). Xu et al ( Xu et al, 2019 ) developed a PDA-mediated dexamethasone plus minocycline-loaded liposomes on PEEK substrates.…”