Antimicrobial Activity of Minocycline-Loaded Genipin-Crosslinked Nano-Fibrous Chitosan Mats for Guided Tissue Regeneration

Abstract

Antimicrobial delivery has been advocated for guided tissue regeneration (GTR) or guided bone regeneration (GBR) therapies involving patients with aggressive or unresolved periodontitis/peri-implantitis. Electrospun chitosan membranes demonstrate several advantages over traditional GTR barrier membranes because they stimulate healing, mimic the topology of the extracellular matrix, and allow for diffusion of nutrients and wastes into/out of the graft site, and were shown to stimulate bone formation in a rabbit calvarial critical-size defect model. Previously, we have shown improvements in mechanical properties and degradation kinetics by crosslinking electrospun membranes with 5 mM or 10 mM genipin. We have also demonstrated the ability of elecrospun chitosan membranes to inhibit lippopolysaccharide (LPS)-induced monocyte activation. In this study, minocycline was incorporated into the chitosan membrane by passive absorption at 5 or 10 mg/mL. The minocycline-loaded membranes and control membranes (carrier only) were tested against Porphyromonas gingivalis (P. gingivalis) by repeated zone of inhibition (ZOI) measurements. Testing showed that uncrosslinked and genipin-crosslinked membranes have similar capacity to absorb aqueous solutions (swelling ratio 1.7 -2.2). Minocycline loading resulted in bacterial inhibition for up to 8 days from crosslinked membranes (with 11 mm initial ZOI) whereas uncrosslinked membranes loaded with minocycline only inhibited bacteria for 4 days (with 8 mm initial ZOI). These in vitro results suggest that genipin-crosslinked electrospun chitosan membranes loaded with minocycline may be able to reduce early bacterial contamination of GTR graft sites.

Simvastatin loaded chitosan guided bone regeneration membranes stimulate bone healing

“…All membrane groups were biocompatible, with minimal inflammation. These results were similar to previous studies, where membranes treated with butyric anhydride (BA‐ another short‐chain FA) or other crosslinking agents also showed minimal inflammation in vivo 1,14,20,25 . None of the drug‐loaded membranes showed more inflammation than non‐loaded membranes, confirming release of non‐toxic levels of SMV.…”

“…ESCMs were electrospun using an in‐house box at room temperature and 40–60% humidity 2,19,20 . Chitosan (5.5% w/v) was dissolved in TFA‐DCM (70–30), loaded into 10 ml syringe with 20‐gauge blunt needle, and electrospun at 27 kV onto aluminum foil covered collector plate, rotating at ~8.4 rpm.…”

Asymmetric Collagen/chitosan Membrane Containing Minocycline-loaded Chitosan Nanoparticles for Guided Bone Regeneration

“…Currently, little efforts has been spent on improving the antibacterial function of barrier membranes. Minocycline loading electrospun chitosan membranes have been shown to reduce early bacterial contamination of GBR graft sites 5 . Furthermore, minocycline has also proven to be an effective antimicrobial agent in periodontal therapy by inhibiting MMPs, a process in which both direct and indirect mechanisms seem to be involved 27 .…”

“…Currently, guided bone regeneration (GBR) is applied to restore alveolar bone, a process in which a GBR membrane is used to isolate periodontal bone defects from gingival connective tissue, so that newly formed bone can grow along the defect margins of alveolar bone34. However, a major issue with current GBR membranes is that they are susceptible to infection due to their exposure to pathogens colonization at wound sites in the process of bone healing, which decreases the amount of regenerated bone56. Clinically, antibiotic ointments are commonly applied to avoid the infection after GBR application, which increases the number of follow-up visits.…”

“…The antibacterial GBR membranes were prepared by loading antibacterial agents such as chlorhexidine, tetracycline, amoxicillin and minocycline 5 7 8 9 . Of these antibiotics, minocycline (7-dimethylamino-6-dimethyl-6-deoxytetracycline) is a semi-synthetic tetracycline derivative that has been used to inhibit both Gram-positive and Gram-negative bacteria by inhibiting bacterial protein synthesis through its binding to bacterial 30S ribosomal subunits 10 .…”