Tissue- and organ-selective biodistribution of NIR fluorescent quantum dots.

A significant portion of the field of nanomedicine is predicated on being able to target nanoparticles to sites of disease. However, in vivo biodistribution and clearance of nanoparticles are poorly understood. In this study, a novel formulation of near-infrared fluorescent InAs(ZnS) quantum dots was synthesized and coated with a systematically increasing chain length of PEG. We found that varying PEG chain length resulted in major changes in organ/tissue-selective biodistribution and clearance from the body.

Use of mineral trioxide aggregate in the open apex of a maxillary first premolar.

Mineral trioxide aggregate (MTA) has shown potential as a root-end filling material. This clinical case describes the successful treatment of a premolar with an open apex using MTA and the warm gutta-percha technique. The results suggested that MTA may be used as an apical filling material in permanent teeth with multiple canals.

Use of mineral trioxide aggregrate in the non-surgical repair of perforating invasive cervical resorption.

Mineral trioxide aggregate (MTA) has shown potential as a repair material for perforations. This clinical case demonstrates that when MTA was used as a repair material for root perforation due to invasive cervical resorption, the tooth was well in function for 27 months. Both clinical and radiographic follow-up showed a stable condition without any probing defect, ongoing root resorption, or apical pathosis.

Immobilization of aminophenylboronic acid on magnetic beads for the direct determination of glycoproteins by matrix assisted laser desorption ionization mass spectrometry.

Aminophenylboronic acid (APBA) has been immobilized on magnetic beads for the direct determination of glycoprotein by matrix assisted laser desorption/ionizaton time of flight mass spectrometry (MALDI-TOF-MS). An APBA layer was formed on the surface of carboxylic acid terminated magnetic beads by coupling with carbodiimide and subsequently reacted with an N-hydroxysuccinimide moiety. The immobilized APBA was identified by MALDI-TOF-MS without a matrix. Glycoproteins, such as HbA1c, fibrinogen, or RNase B were separated and desalted using APBA magnetic beads by simply washing the magnetic beads and then separating them by external magnet. Proteins can be identified by direct determination of proteins on beads on MALDI plate and confirmed again by peptide mass finger printing after digestion of proteins on magnetic beads by trypsin. Fluorescence image with a FITC tagging protein using confocal laser microscopy showed the difference of immobilization efficiency between glycoproteins and nonglycoproteins. The methods developed within this work allow the simple treatment and enrichment of glycoproteins as well as direct determination of proteins on beads by MALDI-TOF-MS.

Clinicopathologic findings after nasolacrimal polyurethane stent implantations.

PURPOSE: To evaluate the results of nasolacrimal polyurethane stent implantations for the treatment of primary acquired nasolacrimal duct obstruction, and to determine the effects of various surgical procedures, including stent removal, in subsequent nasolacrimal duct obstruction. METHODS: This study included 15 patients who had nasolacrimal polyurethane implantations for the treatment of primary acquired nasolacrimal duct obstruction. Occluded stents were removed either by nasal endoscopy or during dacryocystorhinostomy (DCR). Cultures and biopsies were performed on the removed stents, and the results of the secondary DCR were analyzed for a 6-month follow-up period. RESULTS: During stent removal surgery, various degrees of chronic inflammatory reaction and fibrous tissue formation were detected in the lacrimal sac and nasolacrimal duct. Formations of granuloma and fibrous tissue were found in 15 eyes, and culture-positive reaction were found in nine of the 15 eyes. Conventional dacryocystorhinostomy surgery was performed in nine of the 15 eyes and a silicone tube was located at the canaliculi. Subjective and objective outcome were favorable in 13 of the 15 eyes. CONCLUSIONS: The success rate of nasolacrimal polyurethane stent implantation for the treatment of primary acquired nasolacrimal duct obstruction is low. This may result from a chronic inflammatory reaction. Despite the low success rate of nasolacrimal polyurethane stent implantation, the success rate of endonasal DCR as a subsequent surgery is favorable.

Near-infrared fluorescence imaging for noninvasive trafficking of scaffold degradation.

Biodegradable scaffolds could revolutionize tissue engineering and regenerative medicine; however, in vivo matrix degradation and tissue ingrowth processes are not fully understood. Currently a large number of samples and animals are required to track biodegradation of implanted scaffolds, and such nonconsecutive single-time-point information from various batches result in inaccurate conclusions. To overcome this limitation, we developed functional biodegradable scaffolds by employing invisible near-infrared fluorescence and followed their degradation behaviors in vitro and in vivo. Using optical fluorescence imaging, the degradation could be quantified in real-time, while tissue ingrowth was tracked by measuring vascularization using magnetic resonance imaging in the same animal over a month. Moreover, we optimized the in vitro process of enzyme-based biodegradation to predict implanted scaffold behaviors in vivo, which was closely related to the site of inoculation. This combined multimodal imaging will benefit tissue engineers by saving time, reducing animal numbers, and offering more accurate conclusions.