Utility of Triethyloxonium Tetrafluoroborate for Chloride Removal during Sarcosine N-Carboxyanhydride Synthesis: Improving NCA Purity.

The clinical translation of polysarcosine (pSar) as polyethylene glycol (PEG) replacement in the development of novel nanomedicines creates a broad demand of polymeric material in high-quality making high-purity sarcosine N-carboxyanhydride (Sar-NCA) as monomer for its production inevitable. Within this report, we present the use of triethyloxonium tetrafluoroborate in Sar-NCA synthesis with focus on amino acid and chloride impurities to avoid the sublimation of Sar-NCAs. With a view towards upscaling into kilogram or ton scale, a new methodology of monomer purification is introduced by utilizing the Meerwein's Salt triethyloxonium tetrafluoroborate to remove chloride impurities by covalent binding and converting chloride ions into volatile products within a single step. The novel straightforward technique enables access to monomers with significantly reduced chloride content (<100 ppm) compared to Sar-NCA derived by synthesis or sublimation. The derived monomers enable the controlled-living polymerization in DMF and provide access to pSar polymers with Poisson-like molecular weight distribution within a high range of chain lengths (Xn 25-200). In conclusion, the reported method can be easily applied to Sar-NCA synthesis or purification of commercially available pSar-NCAs and eases access to well-defined hetero-telechelic pSar polymers.

Neglected Dislocation in Adults: A New Therapeutic Strategy for an Uncommon Condition.

(1) Background: Neglected hip dislocation is an uncommon condition, especially in developed countries because dislocations are considered trauma emergencies and thus are treated early. They are usually treated with methods used in commonly occurring dislocations. The aim of this study is to detail a two-stage strategy for neglected hip dislocations in adults applied in a complicated case. (2) Case presentation: We present a complicated case of neglected hip dislocation in a patient with an associated neurological condition. Two-stage open reduction was performed combined with arthrodiastasis and Ilizarov external fixators. After complications requiring a third intervention, the joint was stabilized, and the patient has presented no more episodes to date. (3) Conclusions: Arthrodiastasis has been used to treat these conditions. Comparing it with the other methods described in the literature, it seems to be a good therapeutic strategy, especially in elderly patients. Because of the limited number of studies, we cannot establish the most efficient therapeutic method, but we believe that the described strategy can be useful for patients with this condition.

Elbow septic arthritis in children: clinical presentation and management.

The elbow is a rare location for septic arthritis, and this fact may produce diagnostic errors. The purpose of this study is to determine the most typical clinical presentation and to evaluate the management and functional outcome of these patients. We present our experience with this entity. This is a retrospective study of seven cases between February 2004 and November 2007, five girls and two boys with a mean age of 2.8 years, ranging from 1.2 to 4.9 years. We explain our diagnosis criteria and management algorithm. Functional results were evaluated using the Mayo Elbow Performance Score. It is necessary to suspect septic arthritis in an elbow with persistent pain and functional limitation (24-48 h) and no earlier trauma. The most frequent infectious agent is Staphylococcus aureus. Using specific antibiotics until the disappearance of radiological changes we have obtained excellent clinical results according to the Mayo Elbow Performance Score.