In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile

<p>Abstract</p> <p>Background</p> <p>Polymethyl-methacrylate (PMMA) beads releasing antibiotics are used extensively to treat osteomyelitis, but require surgical removal afterwards because they do not degrade.</p> <p>Methods</p> <p>As an alternative option, this report compares the <it>in vitro </it>gentamicin release profile from clinically used, biodegradable carrier-materials: six injectable cements and six granule-types. Cement cylinders and coated granules containing 3% gentamicin were submerged in dH₂O and placed in a 48-sample parallel drug-release system. At regular intervals (30, 90, 180 min. and then every 24 h, for 21 days), the release fluid was exchanged and the gentamicin concentration was measured. The activity of released gentamicin was tested on <it>Staphylococcus aureus</it>.</p> <p>Results</p> <p>All combinations showed initial burst-release of active gentamicin, two cements had continuous-release (17 days). The relative release of all cements (36–85%) and granules (30–62%) was higher than previously reported for injectable PMMA-cements (up to 17%) and comparable to other biodegradable carriers. From the cements residual gentamicin could be extracted, whereas the granules released all gentamicin that had adhered to the surface.</p> <p>Conclusion</p> <p>The high release achieved shows great promise for clinical application of these biodegradable drug-carriers. Using the appropriate combination, the required release profile (burst or sustained) may be achieved.</p

The effect of traumatic dental occlusion on the degradation of periodontal bone in rats

Context: A better understanding of the relation between traumatic dental occlusion and periodontal changes is needed. Aims: This study aimed to evaluate the pattern of osteoclastic activity in the periodontal bone in front of the traumatic dental occlusion in rat molars. Patients and Methods: Traumatic dental occlusion (TO) was induced in twenty rats, which were sacrificed after periods of 2, 5, 7, and 14 days. Transversal histological sections of both jaws were stained with tartrate-resistant acid phosphatase and hematoxylin and eosin. Mann–Whitney U-test was used for group comparison, and Pearson's correlation test was applied for the number of osteoclasts and bone area (BA). Results: Traumatic dental occlusion caused an increase in the number of osteoclasts in the bone of the upper and lower right first molar from days 2–5 to 2–14, respectively. In the TO groups, the number of osteoclasts on the lamina dura and in the center of the alveolar bone septum, respectively, increased almost 4-fold and 9-fold in the lower jaw; and 3-fold and 5-fold in the upper jaw, during all periods. In the TO groups, the BA of the alveolar bone septum was substantially reduced. There was a negative correlation between the number of osteoclasts and BA in both jaws during all experimental periods. Conclusions: Traumatic dental occlusion increases osteoclast activity in the alveolar lamina dura and in the center of alveolar bone and stimulates a higher degradation in the center of the alveolar bone septum

In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile-3

<p><b>Copyright information:</b></p><p>Taken from "In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile"</p><p>BMC Musculoskeletal Disorders 2006;7():18-18.</p><p>Published online 26 Feb 2006</p><p>PMCID:PMC1459860.</p><p>Copyright © 2006 Stallmann et al; licensee BioMed Central Ltd.</p

In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile-2

<p><b>Copyright information:</b></p><p>Taken from "In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile"</p><p>BMC Musculoskeletal Disorders 2006;7():18-18.</p><p>Published online 26 Feb 2006</p><p>PMCID:PMC1459860.</p><p>Copyright © 2006 Stallmann et al; licensee BioMed Central Ltd.</p

In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile-6

<p><b>Copyright information:</b></p><p>Taken from "In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile"</p><p>BMC Musculoskeletal Disorders 2006;7():18-18.</p><p>Published online 26 Feb 2006</p><p>PMCID:PMC1459860.</p><p>Copyright © 2006 Stallmann et al; licensee BioMed Central Ltd.</p

In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile-4

<p><b>Copyright information:</b></p><p>Taken from "In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile"</p><p>BMC Musculoskeletal Disorders 2006;7():18-18.</p><p>Published online 26 Feb 2006</p><p>PMCID:PMC1459860.</p><p>Copyright © 2006 Stallmann et al; licensee BioMed Central Ltd.</p

In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile-5

<p><b>Copyright information:</b></p><p>Taken from "In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile"</p><p>BMC Musculoskeletal Disorders 2006;7():18-18.</p><p>Published online 26 Feb 2006</p><p>PMCID:PMC1459860.</p><p>Copyright © 2006 Stallmann et al; licensee BioMed Central Ltd.</p

In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile-1

<p><b>Copyright information:</b></p><p>Taken from "In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile"</p><p>BMC Musculoskeletal Disorders 2006;7():18-18.</p><p>Published online 26 Feb 2006</p><p>PMCID:PMC1459860.</p><p>Copyright © 2006 Stallmann et al; licensee BioMed Central Ltd.</p