Robust antibacterial activity of functionalized carbon nanotube- levofloxacine conjugate based on in vitro and in vivo studies.

A new nano-antibiotic was synthesized from the conjugation of multi-walled carbon nanotubes with levofloxacin (MWCNT-LVX) through covalent grafting of drug with surface-modified carbon nanotubes in order to achieve an effective, safe, fast-acting nano-drug with the minimal side effects. This study is the first report on the evaluation of in vitro cell viability and antibacterial activity of nano-antibiotic along in addition to the in vivo antibacterial activity in a burn wound model. The drug-loading and release profile at different pH levels was determined using an ultraviolet-visible spectrometer. MWCNT-LVX was synthesized by a simple, reproducible and cost-effective method for the first time and characterized using various techniques, such as scanning electron microscope, transmission electron microscopy, and Brunauer-Emmett-Teller analysis, and so forth. The noncytotoxic nano-antibiotic showed more satisfactory in vitro antibacterial activity against Staphylococcus aureus compared to Pseudomona aeruginosa. The novel synthetic nano-drug possessed high loading capacity and pH-sensitive release profile; resultantly, it exhibited very potent bactericidal activity in a mouse S. aureus wound infection model compared to LVX. Based on the results, the antibacterial properties of the drug enhanced after conjugating with surface-modified MWCNTs. The nano-antibiotic has great industrialization potential for the simple route of synthesis, no toxicity, proper drug loading and release, low effective dose, and strong activity against wound infections. In virtue of unique properties, MWCNTs can serve as a controlled release and delivery system for drugs. The easy penetration to biological membranes and barriers can also increase the drug delivery at lower doses compared to the main drug alone, which can lead to the reduction of its side effects. Hence, MWCNTs can be considered a promising nano-carrier of LVX in the treatment of skin infections.

Comparing the squatting position and traditional sitting position for ease of spinal needle placement: a randomized clinical trial.

BACKGROUND: previous evidences suggested that traditional sitting position (flexion of knees approximately 90°, and adduction of hips while feet rest on a stool) and hamstring stretch position (sitting position with maximum extension of knees, adduction of hips, and forward bending) both reversed the lumbar lordosis and the number of spinal needle-bone contacts were identical when placing patients in these positions for neuraxial block. OBJECTIVES: In this study, we suggested that squatting position reverses the lumbar lordosis and reduces the number of spinal needle bone contacts better than a traditional sitting position. PATIENTS AND METHODS: Two hundred and thirty six patients ASA (American Society of Anesthesiologist) class I or II aged 18 to 75 years scheduled for elective surgeries under elective spinal anesthesia were randomized into two groups. We compared the traditional sitting and squatting positions. Our primary endpoint was the number of spinal needle-bone contacts, and secondary endpoint was ease of needle insertion or space identification. RESULTS: The total number of spinal needle bone contact was statistically lower in the squatting position compared to traditional sitting position group (222 versus 230 respectively, P = 0.01). Insertion of needle was easy in 97 (87%) and 94 (84%) of patients and difficult in 20 (18%) and 17 (15%) of patients in traditional sitting and squatting positions, respectively (P = 0.59 and P = 0.12). Needle insertion was not impossible in any patients. CONCLUSIONS: In squatting position the number of spinal needle-bone contacts was lower compared to the traditional sitting position, nonetheless ease of needle insertion or space identification was the same in the both groups.