Bone Fillers with Balance Between Biocompatibility and Antimicrobial Properties

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Nanotechnology

Background:

• Bone regeneration is a significant clinical need, with current biomaterials facing challenges like implant-associated infections and poor biocompatibility.
• Existing bone graft materials, often collagen and ceramic-based, aim to mimic the natural bone matrix but require improvement in infection resistance and host integration.
• Developing bone fillers with simultaneous antimicrobial properties and enhanced biocompatibility remains a critical research challenge.

Purpose of the Study:

• To develop and characterize novel biomimetic bone fillers with integrated antimicrobial properties and biocompatibility for human bone marrow-derived mesenchymal stem cells (BMSCs).
• To investigate the potential of incorporating zinc oxide (ZnO) functionalized with *Satureja thymbra* L. essential oils into a collagen-calcium triphosphate scaffold.
• To evaluate the efficacy of the developed bone fillers in promoting bone growth, mineralization, and formation while ensuring safety for BMSCs.

Main Methods:

• Bone fillers were fabricated using a 1:1 ratio of Type I collagen and calcium triphosphate, combined with varying percentages of ZnO functionalized with *Satureja thymbra* L. essential oils, via freeze-drying.
• Characterization included Fourier Transform Infrared Spectroscopy (FT-FTIR), Scanning Electron Microscopy (SEM), assessment of water uptake and biodegradability.
• Antimicrobial activity was tested against *Staphylococcus aureus* and *Escherichia coli*, alongside evaluation of human BMSC viability and proliferation.

Main Results:

• The novel bone fillers exhibited higher porosity with interconnected pores and demonstrated gradual resorption over time.
• The materials successfully balanced potent antimicrobial properties against tested bacteria with excellent biocompatibility towards human BMSCs.
• Characterization confirmed the structural integrity and desired properties of the developed biomimetic bone fillers.

Conclusions:

• The developed biomimetic bone fillers, incorporating collagen, calcium triphosphate, ZnO, and *Satureja thymbra* L. essential oils, represent a promising advancement in bone regeneration.
• These materials effectively address the dual challenges of infection prevention and biocompatibility, crucial for successful bone grafting.
• The study highlights the potential of this novel composite as an ideal bone filler for clinical applications, promoting bone healing and regeneration.