Vesicular Nanocarriers: A Potential Platform for Topical/Transdermal Delivery of Antibiotics.

BACKGROUND: Bacterial infections are becoming difficult to treat nowadays due to the development of resistance towards conventional treatments. Conventional topical formulations loaded with antibiotics display various disadvantages, like high dosing frequency, high toxicity, and poor patient compliance. The former limitations may sometimes lead to severe complications and hospitalization of patients. However, these can be overcome by employing vesicular nanocarriers for the delivery of antibiotics following the topical/transdermal route. OBJECTIVE: The objective of this review paper was to summarize the role of vesicular nanocarriers, like liposomes, elastic liposomes, niosomes, ethosomes, solid lipid nanoparticles, nanostructured lipid carriers, and nanoemulsions for topical/transdermal delivery of antibiotics, and patents associated with them. METHODS: Literature for the present review was collected using various search engines, like PubMed, Google Scholar, and Google Patents. RESULTS: Various literature investigations have revealed the in vitro and preclinical efficacy of vesicular nanocarrier systems in the delivery of antibiotics following the topical/transdermal route. CONCLUSION: Vesicular nanocarrier systems, via targeted delivery, may subside various side effects of antibiotics associated with conventional delivery, like high dosing frequency and poor patient compliance. However, their existence in the pharmaceutical market will be governed by effective clinical assessment and scale-up methodologies.

Somatosensory substrates of flight control in bats.

Flight maneuvers require rapid sensory integration to generate adaptive motor output. Bats achieve remarkable agility with modified forelimbs that serve as airfoils while retaining capacity for object manipulation. Wing sensory inputs provide behaviorally relevant information to guide flight; however, components of wing sensory-motor circuits have not been analyzed. Here, we elucidate the organization of wing innervation in an insectivore, the big brown bat, Eptesicus fuscus. We demonstrate that wing sensory innervation differs from other vertebrate forelimbs, revealing a peripheral basis for the atypical topographic organization reported for bat somatosensory nuclei. Furthermore, the wing is innervated by an unusual complement of sensory neurons poised to report airflow and touch. Finally, we report that cortical neurons encode tactile and airflow inputs with sparse activity patterns. Together, our findings identify neural substrates of somatosensation in the bat wing and imply that evolutionary pressures giving rise to mammalian flight led to unusual sensorimotor projections.

Bat wing sensors support flight control.

Bats are the only mammals capable of powered flight, and they perform impressive aerial maneuvers like tight turns, hovering, and perching upside down. The bat wing contains five digits, and its specialized membrane is covered with stiff, microscopically small, domed hairs. We provide here unique empirical evidence that the tactile receptors associated with these hairs are involved in sensorimotor flight control by providing aerodynamic feedback. We found that neurons in bat primary somatosensory cortex respond with directional sensitivity to stimulation of the wing hairs with low-speed airflow. Wing hairs mostly preferred reversed airflow, which occurs under flight conditions when the airflow separates and vortices form. This finding suggests that the hairs act as an array of sensors to monitor flight speed and/or airflow conditions that indicate stall. Depilation of different functional regions of the bats' wing membrane altered the flight behavior in obstacle avoidance tasks by reducing aerial maneuverability, as indicated by decreased turning angles and increased flight speed.