Related Experiment Video
Updated: Mar 5, 2026
Half-segmental Diaphyseal Bone Defect Model in Rats for Evaluating Bone Substitute Performance in Load-bearing Regions
Published on: December 30, 2025
A minocycline-releasing PMMA system as a space maintainer for staged bone reconstructions-in vitro antibacterial,
Tiago Silva1, Liliana Grenho1, Joana Barros2,3,4
1Laboratory for Bone Metabolism and Regeneration-Faculty of Dental Medicine, U. Porto-Porto, Portugal.
Abstract:
In the present work, we study the development and biological characterization of a polymethyl methacrylate (PMMA)-based minocycline delivery system, to be used as a space maintainer within craniofacial staged regenerative interventions. The developed delivery systems were characterized regarding solid state characteristics and assayed in vitro for antibacterial and anti-inflammatory activity, and cytocompatibility with human bone cells. A drug release profile allowed for an initial burst release and a more sustained and controlled release over time, with minimum inhibitory concentrations for the assayed and relevant pathogenic bacteria (i.e., Staphylococcus aureus, slime-producer Staphylococcus epidermidis and Escherichia coli) being easily attained in the early time points, and sustained up to 72 h. Furthermore, an improved osteoblastic cell response-with enhancement of cell adhesion and cell proliferation-and increased anti-inflammatory activity were verified in developed systems, compared to a control (non minocycline-loaded PMMA cement). The obtained results converge to support the possible efficacy of the developed PMMA-based minocycline delivery systems for the clinical management of complex craniofacial trauma. Here, biomaterials with space maintenance properties are necessary for the management of staged reconstructive approaches, thus minimizing the risk of peri-operative infections and enhancing the local tissue healing and early stages of regeneration.
Insights
This study developed a polymethyl methacrylate (PMMA)-based minocycline delivery system for craniofacial regeneration. The system shows antibacterial, anti-inflammatory, and bone cell-enhancing properties, aiding in complex trauma management.
Area of Science:
- Biomaterials Science
- Regenerative Medicine
- Craniofacial Surgery
Background:
- Craniofacial trauma requires staged regenerative interventions.
- Space maintainers are crucial for reconstructive approaches.
- Minimizing infection risk and enhancing healing are key challenges.
Purpose of the Study:
- To develop and biologically characterize a polymethyl methacrylate (PMMA)-based minocycline delivery system.
- To evaluate its potential as a space maintainer in craniofacial regeneration.
- To assess its antibacterial, anti-inflammatory, and cytocompatibility properties.
Main Methods:
- Development of PMMA-based minocycline delivery systems.
- Solid-state characterization of the delivery systems.
- In vitro assays for antibacterial activity (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli), anti-inflammatory activity, and cytocompatibility with human bone cells.
- Drug release profile analysis.
Main Results:
- The system demonstrated controlled minocycline release, achieving sustained minimum inhibitory concentrations against key pathogens for up to 72 hours.
- Enhanced osteoblastic cell adhesion and proliferation were observed.
- Increased anti-inflammatory activity was verified compared to control PMMA.
- The system showed good cytocompatibility with human bone cells.
Conclusions:
- The developed PMMA-based minocycline delivery system shows promise as a space maintainer for craniofacial regeneration.
- It effectively combats relevant bacteria and reduces inflammation.
- The system supports osteoblastic cell response, aiding tissue healing and regeneration in complex craniofacial trauma cases.
