Bioresorbable plain and ciprofloxacin-releasing self-reinforced PLGA 80/20 implants' suitability for craniofacial surgery:histological and mechanical assessment
Abstract Ciprofloxacin was incorporated to plain bioresorbable self-reinforced polylactide/glycolyde 80/20 screws and tacks (ciprofloxacin releasing SR-PLGA). These implants were compared to otherwise similar conventional fixation devices. The effect of the ciprofloxacin addition on the pull-out fo...
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| Format: | Doctoral Thesis |
| Language: | English |
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University of Oulu
2007
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| Online Access: | http://urn.fi/urn:isbn:9789514285769 http://nbn-resolving.de/urn:isbn:9789514285769 |
| Summary: | Abstract
Ciprofloxacin was incorporated to plain bioresorbable self-reinforced polylactide/glycolyde 80/20 screws and tacks (ciprofloxacin releasing SR-PLGA). These implants were compared to otherwise similar conventional fixation devices. The effect of the ciprofloxacin addition on the pull-out force of screws and tacks was evaluated in human cadaver cranial bones. SR-PLGA tacks applied to cranial bone with a special applicator gun had a similar holding power as screws. Addition of the antibiotic compromised the strength of the screws so that ciprofloxacin-containing PLGA screws had lower pull-out strength than corresponding plain PLGA screws. Scanning electron microscopy showed that the fibrillar strip-like microstructure of plain SR-PLGA screws turned into a coarse uni-axial platelet-like pattern as a result of ciprofloxacin addition. It is concluded that this type of 4 mm long and 1.5 mm diameter ciprofloxacin-containing screws can only be used in non-load-bearing or slightly load-bearing applications. Tissue reactions elicited by plain bioresorbable self-reinforced polylactide/glycolide (SR-PLGA) 80/20 screws were compared to similar but ciprofloxacin-releasing SR-PLGA fixation devices in rabbit cranial bone. Plain and ciprofloxacin-PLGA 80/20 screws elicited only mild inflammatory reactions upon implantation in rabbit cranial bone, but they did not interfere with osteoblast activity in up to 72 week long follow-up. Release of the antibiotic from ciprofloxacin-PLGA screws was gradual and the drug concentration in bone tissues was still higher at 8 weeks than the minimal inhibitory concentration (MIC) of ciprofloxacin for S. aureus (0.1–1.0 μg/g). Ciprofloxacin-releasing SR-PLGA screws can find clinical usage in the prevention of implant-related infections in osteofixation in craniomaxillofacial bones in non-load-bearing or slightly load-bearing applications. Larger 6 mm long and 2 mm diameter ciprofloxacin-releasing tacks had a similar holding power to cranial bone as conventional tacks. Tacks can be recommended for clinical use as the application procedure saves time and costs.
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