Antibacterial properties and regenerative potential of Sr2+ and Ce3+ doped fluorapatites; a potential solution for peri-implantitis.

Scaffolds and implants in orthopaedics and regenerative dentistry usually fail because of bacterial infections. A promising solution would be the development of biomaterials with both significant regenerative potential and enhanced antibacterial activity. Working towards this direction, fluorapatite was synthesised and doped with Sr2+ and Ce3+ ions in order to tailor its properties. After experiments with four common bacteria (i.e. E. Coli, S. Aureus, B. Subtilis, B. Cereus), it was found that the undoped and the Ce3+ doped fluorapatites present better antibacterial response than the Sr2+ doped material. The synthesised minerals were incorporated into chitosan scaffolds and tested with Dental Pulp Stem Cells (DPSCs) to check their regenerative potential. As was expected, the scaffolds containing Sr2+-doped fluorapatite, presented high osteoconductivity leading to the differentiation of the DPSCs into osteoblasts. Similar results were obtained for the Ce3+-doped material, since both the concentration of osteocalcin and the RUNX2 gene expression were considerably higher than that for the un-doped mineral. Overall, it was shown that doping with Ce3+ retains the good antibacterial profile of fluorapatite and enhances its regenerative potential, which makes it a promising option for dealing with conditions where healing of hard tissues is compromised by bacterial contamination.

Peripherally inserted central venous catheters: frequency of complications in premature newborn depends on the insertion site.

OBJECTIVE: The use of peripherally inserted central venous catheters (PICC lines) has reduced the mortality and morbidity of premature newborns. The usual sites of insertion are the veins in the upper arms but other locations are being used as well. STUDY DESIGN: To examine whether using the axillary vein as a site of insertion of a PICC line affects the frequency of complications. Our study has a clinical trial design. A total of 62 neonates that had a PICC line inserted were recruited and randomly divided equally in two groups: in Group A (mean birth weight, standard deviation (s.d.)=1353 (142) g), the PICC line was inserted through the axillary vein, and in Group B (birth weight=1308 (112) g), the PICC line was inserted in other sites further from the axillary vein. The outcomes measured were the total PICC line-related complications, the reason for removing the catheter, the number of total attempts until successful insertion and the mean duration of stay of the catheter. The likelihood of having an adverse outcome was assessed with Mantel-Haenszel odds ratio (OR). RESULTS: Premature neonates with axillary PICC lines were 12 times less likely to have line-related complications (inflammation, blockage, edema, infection) as compared with any other site of insertion (OR= 95%, confidence interval (CI)=0.10 (0.01 to 0.8)) and they were seven times more likely to have the PICC line removed because they achieved full enteral nutrition as compared with the other causes (OR 95%, confidence interval (CI)=10.35 (4.88 to 21.96)). There was no statistical difference between the two groups in the number of attempts until successful PICC line insertion (P=0.667) and the mean duration of stay of the PICC line (P=0.97). CONCLUSION: The use of the axillary vein as a site of insertion of a PICC line was correlated with significantly less complications in premature newborns as opposed to the other sites of insertion.

Platelet distribution width: a simple, practical and specific marker of activation of coagulation.

BACKGROUND: Platelet indices are potentially useful markers for the early diagnosis of thromboembolic diseases. An increase in both mean platelet volume (MPV) and platelet distribution width (PDW) due to platelet activation, resulting from platelet swelling and pseudopodia formation was hypothesized. METHODS: Platelet indices (MPV and PDW) in three groups of persons, using impedance and optical technology were measured. The first group consisted of patients with established platelet activation and healthy control subjects. The second study group included pregnant women in different trimesters of pregnancy. The effect of storage time on MPV and PDW in blood samples of a third group of randomly chosen patients was also assessed. RESULTS: There was a significant increase in MPV (P<0.001) and PDW (P<0.001) in patients with confirmed platelet activation compared to healthy control subjects. Only PDW showed a significant increase from the first to the third trimester of pregnancy (P=0.009). Temporal changes of MPV and PDW over storage time revealed a significant increase in MPV (P<0.001), in contrast to a significant decrease in PDW (P<0.05). CONCLUSION: MPV and PDW are simple platelet indices, which increase during platelet activation. PDW is a more specific marker of platelet activation, since it does not increase during simple platelet swelling.