Quercetin-gold nanorods incorporated into nanofibers: development, optimization and cytotoxicity.

Herein, a polymeric nanofiber scaffold loaded with Quercetin (Quer)-gold nanorods (GNR) was developed and characterized. Several parameters related to loading Quer into GNR, incorporating the GNR-Quer into polymeric solutions, and fabricating the nanofibers by electrospinning were optimized. GNR-Quer loaded into a polymeric mixture of poly(lactic-co-glycolic acid) (PLGA) (21%) and poloxamer 407 (23%) has produced intact GNR-Quer-nanofibers with enhanced physical and mechanical properties. GNR-Quer-nanofibers demonstrated a slow pattern of Quer release over time compared to nanofibers free of GNR-Quer. Dynamic mechanical thermal analysis (DMTA) revealed enhanced uniformity and homogeneity of the GNR-Quer-nanofibers. GNR-Quer-nanofibers demonstrated a high ability to retain water upon incubation in phosphate buffer saline (PBS) for 24 h compared to nanofibers free of GNR-Quer. A cellular toxicity study indicated that the average cellular viability of human dermal fibroblasts was 76% after 24 h of exposure to the nanofibers containing a low concentration of GNR-Quer.

Liquid chromatography-tandem mass spectrometry for rapid and selective simultaneous determination of fluoroquinolones level in human aqueous humor.

Endophthalmitis, an intraocular infection, may lead to irreversible loss of vision. Antimicrobial chemotherapy is prescribed prior to ocular surgical procedures to avoid endophthalmitis. Fluoroquinolones are the most commonly prescribed and used antibiotics during such procedures. However, the selection of a single entity and proper regimen is not specified in medical guidelines. The objective of this study is to develop a rapid and selective simultaneous high-performance liquid chromatography-tandem mass spectroscopic method to explore the bioavailability of 4 fluoroquinolones, including 0.5% moxifloxacin hydrochloride, 0.3% gatifloxacin, 0.3% ciprofloxacin hydrochloride, and 0.3% ofloxacin, in human aqueous humor after antibiotic topical administration using gemifloxacin as Internal Standard according to the European Medicines Agency (EMA) and US Food and Drug Administration (FDA) guidelines. The newly validated method was capable of accurately and precisely quantifying each antibiotic at the lowest reported lower limit of quantification of 10 ng/mL and operating on a very low pipetting volume of 15 µL, indicating a reliable quantitation of all analytes simultaneously using a very small quantity of aqueous humor with total chromatographic run time of 2.5 min. Sixty-seven patients were divided into 4 groups for each antibiotic. Before the cataract surgery, each group received 4 drops of one of the antibiotics over 1 h, separated by 15 min time interval. After 15-20 min from the last drop, approximately 50-100 µL of aqueous humor was collected during surgery for analysis. The average concentrations of moxifloxacin, gatifloxacin, ofloxacin and ciprofloxacin in aqueous humor samples were 891.8, 271.7, 191.4 and 69.5 ng/mL, respectively. Only moxifloxacin average concentration was higher than the minimum inhibitory concentration for the common endophthalmitis pathogens.