Polyester Urethane Implants for Orbital Trapdoor Fracture Repair in Children.

PURPOSE: The objective of this study was to present the surgical and clinical outcomes of polyester urethane implants in orbital trapdoor fracture repair in children. This is the first study reporting on the use of polyester urethane implants to repair orbital fractures. MATERIALS AND METHODS: A retrospective review was performed of children with orbital trapdoor fracture who underwent surgical repair in the authors' medical center over 6 years. The trapdoor fracture diagnosis was based on clinical and computed topographic findings. RESULTS: Eight patients with trapdoor fracture were identified. All cases were repaired by polyester urethane implant placement. Patients' mean age was 13.5 years and mean follow-up was 13.6 months. All patients had orbital floor fractures. Two fractures also involved the medial wall. Seven patients had inferior rectus muscle entrapment and 1 had medial rectus muscle entrapment. Three patients had residual diplopia on extreme upgaze after the surgical repair. No patient had enophthalmos or infraorbital paresthesia at the end of follow-up. No postoperative complications associated with the used material were reported. CONCLUSION: The polyester urethane implant is a reliable, safe, inexpensive, and effective implant for trapdoor fracture repair in children. It can serve as a promising alternative to implants fabricated from other synthetic materials for orbital floor fracture repair.

Particle size, surface coating, and PEGylation influence the biodistribution of quantum dots in living mice.

This study evaluates the influence of particle size, PEGylation, and surface coating on the quantitative biodistribution of near-infrared-emitting quantum dots (QDs) in mice. Polymer- or peptide-coated 64Cu-labeled QDs 2 or 12 nm in diameter, with or without polyethylene glycol (PEG) of molecular weight 2000, are studied by serial micropositron emission tomography imaging and region-of-interest analysis, as well as transmission electron microscopy and inductively coupled plasma mass spectrometry. PEGylation and peptide coating slow QD uptake into the organs of the reticuloendothelial system (RES), liver and spleen, by a factor of 6-9 and 2-3, respectively. Small particles are in part renally excreted. Peptide-coated particles are cleared from liver faster than physical decay alone would suggest. Renal excretion of small QDs and slowing of RES clearance by PEGylation or peptide surface coating are encouraging steps toward the use of modified QDs for imaging living subjects.