Gaoyang Chen1, Bo Liu2, He Liu1, Hanyang Zhang1, Kerong Yang1, Qingyu Wang1, Jianxun Ding3, Fei Chang4. 1. Department of orthopaedic surgery, 2nd Hospital of Jilin University, No. 218, Ziqiang street, Nanguan District, Changchun 130041, China. 2. Department of orthopaedic surgery, the First Hospital of Jilin University, Changchun, China. 3. Key laboratory of polymer ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China. 4. Department of orthopaedic surgery, 2nd Hospital of Jilin University, No. 218, Ziqiang street, Nanguan District, Changchun 130041, China. Electronic address: ccfei_cn@hotmail.com.
Abstract
BACKGROUND: Antibiotics impregnated calcium phosphate cement (CPC) has emerged as a local treatment of osteomyelitis. However, there is no study investigating the optimal concentrations of vancomycin (VCM) included in CPC to obtain prolonged drug release (≥8 weeks) and also with enough compressive strength (>the normal cancellous bone, 11MPa) for osteomyelitis therapy. Therefore, we bring forward two questions: 1) Was antibiotic activity of the eluates correlated to the load of antibiotics within the cement? 2) Were the mechanical properties of CPC affected by VCM-loading? HYPOTHESIZED: There was an optimal concentrations of vancomycin (VCM) loaded in CPC which could provide sufficient effective antibacterial time (≥8 weeks) and enough compressive strength (>11MPa). MATERIALS AND METHODS: CPC specimens were obtained by incorporating different doses (weigh ratios of 0%, 5%, 10%, 15%, 20%, 25 and 30%) of injectable VCM into CPC. The antibacterial effect of released VCM solution against Staphylococcus aureus was assessed by inhibition ring assays. The physicochemical properties such as compressive strengths were characterized and compared among these specimens. RESULTS: Drug release profiles showed only 5 and 10% VCM-loaded CPC displayed a long enough drug release time (at least 8 weeks) and maintained the eluate concentrations (>4μg/mL) with effective antibacterial ability. The concentration of VCM in 10% group at 8th week was twice higher than 5% group. Compressive strength test showed that the proportional increase of VCM/CPC ratios resulted in a significant decrease of compressive strength (r=-0.906, p<0.001). CONCLUSION: 10% VCM-loaded CPC offered the optimal physicochemical properties and drug releasing profile and appears as the most suitable concentration for clinical use. LEVEL OF EVIDENCE: III.
BACKGROUND: Antibiotics impregnated calcium phosphate cement (CPC) has emerged as a local treatment of osteomyelitis. However, there is no study investigating the optimal concentrations of vancomycin (VCM) included in CPC to obtain prolonged drug release (≥8 weeks) and also with enough compressive strength (>the normal cancellous bone, 11MPa) for osteomyelitis therapy. Therefore, we bring forward two questions: 1) Was antibiotic activity of the eluates correlated to the load of antibiotics within the cement? 2) Were the mechanical properties of CPC affected by VCM-loading? HYPOTHESIZED: There was an optimal concentrations of vancomycin (VCM) loaded in CPC which could provide sufficient effective antibacterial time (≥8 weeks) and enough compressive strength (>11MPa). MATERIALS AND METHODS:CPC specimens were obtained by incorporating different doses (weigh ratios of 0%, 5%, 10%, 15%, 20%, 25 and 30%) of injectable VCM into CPC. The antibacterial effect of released VCM solution against Staphylococcus aureus was assessed by inhibition ring assays. The physicochemical properties such as compressive strengths were characterized and compared among these specimens. RESULTS: Drug release profiles showed only 5 and 10% VCM-loaded CPC displayed a long enough drug release time (at least 8 weeks) and maintained the eluate concentrations (>4μg/mL) with effective antibacterial ability. The concentration of VCM in 10% group at 8th week was twice higher than 5% group. Compressive strength test showed that the proportional increase of VCM/CPC ratios resulted in a significant decrease of compressive strength (r=-0.906, p<0.001). CONCLUSION: 10% VCM-loaded CPC offered the optimal physicochemical properties and drug releasing profile and appears as the most suitable concentration for clinical use. LEVEL OF EVIDENCE: III.