Antimicrobial photodynamic active biomaterials for periodontal regeneration

Abstract Objective Biomaterials for periodontal regeneration may have insufficient mechanical and antimicrobial properties or are difficult to apply under clinical conditions. The aim of the present study was to develop a polymeric bone grafting material of suitable physical appearance and antimicrobial photodynamic activity. Methods Two light curable biomaterials based on urethane dimethacrylate (BioM1) and a tri-armed oligoester-urethane methacrylate (BioM2) that additionally contained a mixture of β-tricalcium phosphate microparticles and 20 wt% photosensitizer mTHPC (PS) were fabricated and analyzed by their compressive strength, flexural strength and modulus of elasticity. Cytotoxicity was observed by incubating eluates and in direct-contact to MC3T3-E1 cells. Antimicrobial activity was ascertained on Porphyromonas gingivalis and Enterococcus faecalis upon illumination with laser light (652 nm, 1 × 100 J/cm 2 , 2 × 100 J/cm 2 ). Results The compressive strength, flexural strength and elastic modulus were, respectively, 311.73 MPa, 22.81 MPa and 318.85 MPa for BioM1 + PS and 742.37 MPa, 7.58 MPa and 406.23 MPa for BioM2 + PS. Both materials did not show any cytotoxic behavior. Single laser-illumination (652 nm) caused total suppression of P. gingivalis (BioM2 + PS), while repeated irradiation reduced E. faecalis by 3.7 (BioM1 + PS) and 3.1 (BioM2 + PS) log-counts. Significance Both materials show excellent mechanical and cytocompatible properties. In addition, irradiation with 652 nm induced significant bacterial suppression. The manufactured biomaterials might enable a more efficient cure of periodontal bone lesions. Due to the mechanical properties functional stability might be increased. Further, the materials are antimicrobial upon illumination with light that enables a trans-mucosal eradication of residual pathogens.