Antibiotic Elution and Mechanical Strength of PMMA Bone Cement Loaded With Borate Bioactive Glass

Abstract

Introduction: Local delivery of antibiotics using bone cement as the delivery vehicle is an established method of managing implant-associated orthopedic infections. Various fillers have been added to cement to increase antibiotic elution, but they often do so at the expense of strength. This study evaluated the effect of adding a borate bioactive glass, previously shown to promote bone formation, on vancomycin elution from PMMA bone cement.Methods: Five cement composites were made: three loaded with borate bioactive glass along with 0, 1, and 5 grams of vancomycin and two without any glass but with 1 and 5 grams vancomycin to serve as controls. The specimens were soaked in PBS. Eluate of vancomycin was collected every 24 hours and analyzed by HPLC. Orthopedic-relevant mechanical properties of each composite were tested over time.Results: The addition of borate bioactive glass provided an increase in vancomycin release at Day 1 and an increase in sustained vancomycin release throughout the treatment period. An 87.6% and 21.1% increase in cumulative vancomycin release was seen for both 1g and 5g loading groups, respectively. Compressive strength of all composites remained above the weight-bearing threshold of 70 MPa throughout the duration of the study with the glass-containing composites showing comparable strength to their respective controls.Conclusion: The incorporation of borate bioactive glass into commercial PMMA bone cement can significantly increase the elution of vancomycin. The mechanical strength of the cement-glass composites remained above 70 MPa even after soaking for 8 weeks, suggesting their suitability for orthopedic weight-bearing applications.

Mechanical and degradation properties of poly(methyl methacrylate) cement/borate bioactive glass composites

“…Bioactivity and cytotoxicity tests could be implemented, simulated body fluid could be used as the solution instead of PBS, and antibiotics could be added to see how 13‐93B3 affects their elution rate and efficacy. One study has already shown that 13‐93B3 in SmartSet MV can increase the elution rate of vancomycin from the cement (Funk et al, ).…”

“…Two previous studies added silicate‐based bioactive glasses to acrylic bone cement and then tested the composite's improved bone‐binding ability and mechanical properties (Shinzato et al, ; Shinzato et al, ). Only three times have investigators reported combining a borate‐based bioactive glass with PMMA cements: one study examined the bioactivity and osseointegration in vivo (Cui et al, ), another examined the delivery of antibiotics from the composite material (Funk, Burkes, Cole, Rahaman, & McIff, ), and the third monitored the conversion of glass to hydroxyapatite‐like precipitate (Cole, Funk, Rahaman, & McIff, ). One of our previously published studies examined the formation of a hydroxyapatite‐like layer on the surface of the composite using scanning electron microscopy and Fourier transform infrared spectroscopy (Cole et al, ), but this study did not examine the important changes in mechanical properties of the composite that occur as the glass dissolves or the rate at which it dissolves.…”

Controlling Antibiotic Release from Polymethylmethacrylate Bone Cement

“…The authors also found that there was a minimal drop of compressive strength between the inclusion of 0.5 g of each antibiotic and 1.0 g of each. Another study of Funk et al [ 54 ] also noted that the compressive strength of all cement composites loaded with vancomycin were higher than the weight-bearing threshold of 70 MPa with no significant difference throughout the duration of the study indicating that the elution of antibiotics does not directly affect the mechanical strength of ALBCs. Research also is being pursued to increase the recommended threshold of loaded antibiotics.…”

The anomaly in bioactive sol–gel borate glasses

“…27 Interest in bioactive borate glasses has led to many 'unique' compositions [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] such as ''1605''. [44][45][46] However, despite fundamental differences between borate and silicate glass structure, many borate compositions, including our previous work, [23][24][25][26]47 have been based on ''traditional'' silicate glass compositions like Bioglass s ''45S5'', 15,[23][24][25][26][47][48][49][50] ''13-93'', 14,16,17,[51][52][53][54][55][56][57][58][59][60][61]…”