Nasal Reconstruction of a Frontonasal Dysplasia via Septal L-Strut Reconstruction Using Costal Cartilage.

OBJECTIVE: Frontonasal dysplasia (FND) is a rare congenital condition. Its major features include hypertelorism, a large and bifid nasal tip, and a broad nasal root. We present our technique of septal L-strut reconstruction using costal cartilage. DESIGN: Retrospective review from June 2008 and August 2017. METHODS: Under general anesthesia, 6 patients with FND underwent septal reconstruction using costal cartilage via open rhinoplasty. We reconstructed the nasal and septal cartilaginous framework by placing columellar struts and cantilever-type grafts. RESULTS: The patients ranged in age from 6 to 13 years old. All were female. The follow-up period ranged from 8 months to 2 years; we encountered no postoperative complications (infection, nasal obstruction, or recurrence). All patients were satisfied with their nasal appearance. CONCLUSIONS: Although the results were not entirely satisfactory from an esthetic point of view, we found that FND can be treated via septal reconstruction with costal cartilage and that the clinical outcomes are reliable and satisfactory. Our approach is a useful option for FND patients.

Histological and molecular biological analysis on the reaction of absorbable thread; Polydioxanone and polycaprolactone in rat model.

INTRODUCTION: One of the most frequently performed anti-aging surgical procedures is thread facelift. Since the 2010s, thread lifts using absorbable polydioxanone (PDO) thread were developed and have become increasingly popular. This research aims to identify the changes in and the mechanisms of absorbable thread-lifting components, namely, PDO (polydioxanone) and PCL (polycaprolactone), with varied absorption periods in the body. METHODS: Four different types of threads, namely, single-stranded thread, 4-stranded thread, 12-stranded thread, and barbed Cog thread, were used for each component. Histological changes in the thread and neighboring tissue of rat model were investigated for 2-week interval, and PCR was conducted for genes related to fibroblast proliferation including type 1α1 collagen, type 3α1 collagen, transforming growth factor beta 1 (TGF-ß1). RESULTS: An increase in the collagen formation in all types of PDO and PCL groups was observed during the first 12 weeks and decreased afterward. Collagen formation decreased later in the PCL thread group significantly than the POD group. PCL thread remained logner in the tissue for over a year regarding POD requiring around 24 weeks of absorption-degradation. A larger surface area between the thread and the tissue induces a greater response in the tissue, resulting in an increase in inflammatory cells, myofibroblasts, and fibroblasts. Results showed a similar pattern of increase in type 1α1 collagen and TGF-ß in the PDO thread group. This suggests that TGF-ß signal transduction leads to fibroblast proliferation that stimulates collagen formation and tissue re-formation. In contrast, only type 3α1 collagen increased in the PCL thread group. CONCLUSION: More collagen formation and tissue responses are induced by PCL thread, remaining longer in the tissue than PDO, leading to more tissue tightening effects that is one of the most important points of face lifting. Morphological comparison of threads shows that not only an increase in surface area between thread and tissue but also multi-strand increase tissue response, which in turn increases tissue maintenance effects.

Migration of substances from food contact plastic materials into foodstuff and their implications for human exposure.

The safety of food contact plastic materials, including PP, PE, PET, PCT, PLA, PBT and cross-linked polyester, was assessed with regard to migrated substances. The migrated concentrations of overall migrants (OMs), terephthalic acid, acetaldehyde, 1,4-butanediol and lead, were determined according to the standards and specifications for utensils, containers and packages in Korea. Food simulants of 4% acetic acid, water and n-heptane were used for the analysis of the substances. The dietary exposures of terephthalic acid, acetaldehyde and 1,4-butanediol were assessed using the dietary concentrations and the food consumption data. As a result, the dietary exposures were considered to be safe comparing to the health-based guidance values. In the case of lead, the margin of exposure (MOE) approach was applied. The MOEs calculated using the UB concentration and mean consumption data were ranged from 3 to 1000, which indicated low concern for health risk. Moreover, in this study, the dietary exposures were estimated by the Korean MFDS and U.S. FDA methods, respectively. As a result, the assessed risks were considered to be low in both cases. Based on the results of current exposure assessments, it could be considered that the food contact plastic materials are properly controlled by the regulatory authorities.

Stimuli-responsive hollow polymer nanoparticles for use as novel delivery systems.

The preparation of biocompatible N-isopropylacrylamide-co-acrylic acid polymer on sacrificial silica (SiO2) nanoparticles is reliably carried out using conventional free radical polymerization. Subsequent removal of the SiO2 core with diluted hydrofluoric acid leads to the formation of uniform hollow polymer structures containing COOH functional groups. The formation and properties of polymer-coated SiO2 and hollow polymer nanoparticles are thoroughly examined by electron microscopes, X-ray photoelectron spectroscopy, and dynamic light scattering. The resulting hollow nanoparticles (approximately 200 nm in diameter) exhibit much greater diameter changes (i.e., swelling and deswelling) than those of polymer-coated SiO2 nanoparticles as a function of pH and/or temperature. This is presumably due to the presence of a large hollow cavity in the polymer nanoparticles. Given their unique features, including their high guest molecule loading capacity, surface functional groups, homogeneity, external stimuli-responsiveness, and biocompatible nature, these hollow nanoparticles can serve as the novel biomedical delivery systems.