Arne Boman

Drug delivery to the spinal cord tagged with nanowire enhances neuroprotective efficacy and functional recovery following trauma to the rat spinal cord

The possibility that drugs attached to innocuous nanowires enhance their delivery within the central nervous system (CNS) and thereby increase their therapeutic efficacy was examined in a rat model of spinal cord injury (SCI). Three compounds—AP173 (SCI‐1), AP713 (SCI‐2), and AP364 (SCI‐5) (Acure Pharma, Uppsala, Sweden)—were tagged with TiO2‐based nanowires using standard procedure. Normal compounds were used for comparison. SCI was produced by making a longitudinal incision into the right dorsal horn of the T10–T11 segments under Equithesin anesthesia. The compounds, either alone or tagged with nanowires, were applied topically within 5 to 10 min after SCI. In these rats, behavioral outcome, blood–spinal cord barrier (BSCB) permeability, edema formation, and cell injury were examined at 5 h after injury. Topical application of normal compounds in high quantity (10 μg in 20 μL) attenuated behavioral dysfunction (3 h after trauma), edema formation, and cell injury, as well as reducing BSCB permeability to Evans blue albumin and 131I. These beneficial effects are most pronounced with AP713 (SCI‐2) treatment. Interestingly, when these compounds were administered in identical conditions after tagging with nanowires, their beneficial effects on functional recovery and spinal cord pathology were further enhanced. However, topical administration of nanowires alone did not influence trauma‐induced spinal cord pathology or motor functions. Taken together, our results, probably for the first time, indicate that drug delivery and therapeutic efficacy are enhanced when the compounds are administered with nanowires.

Ligands to the melanocortin receptors

This review will give a brief overview of the pharmacology of the melanocortin receptors (MCRs) as a background. The review will not handle the patents or patent applications dealing with cloning of the different subtypes of the receptor, since this has been recently reviewed [1]. This review will focus on different ligands acting either as agonists or antagonists to the different subtypes of the receptor, i.e., MC1R, MC3R, MC4R and MC5R. Just recently a number of patent applications have reached the public domain, which describe small peptides or low molecular weight organic compounds binding and acting on the MCRs.

A potent serotonin-modulating compound AP-267 attenuates morphine withdrawal-induced blood-brain barrier dysfunction in rats.

Abstract:  The possibility that a serotonin 5‐HT2c receptor‐modulating compound, AP‐267, will influence spontaneous morphine withdrawal symptoms and the alterations in the brain fluid microenvironment was examined in a rat model. Daily administration of morphine (10 mg/kg, i.p.) for 10 days resulted in dependence of rats as seen by loss of analgesic response. On the 11th day, no morphine administration was given. This resulted in profound withdrawal symptoms 24 h after morphine withdrawal. The magnitude and severity of these symptoms were increased further 48 h after withdrawal. Measurement of the blood‐brain barrier (BBB) permeability, a measure of perturbed brain fluid microenvironment showed leakage of Evans blue and radioiodine tracers in several parts of the brain in rats showing withdrawal symptoms. Whereas, rats treated with AP‐267 either on the 1st day or 2nd day morphine withdrawal showed much less symptoms and leakage of the BBB. Taken together, these observations suggest that (a) stress associated with the withdrawal symptoms are sufficient enough to induce breakdown of the BBB function, and (b) modulation of serotonin 5‐HT2c receptors may have some protective influence on the stress symptoms and the BBB disruption.

Nanowired-Drug Delivery Enhances Neuroprotective Efficacy of Compounds and Reduces Spinal Cord Edema Formation and Improves Functional Outcome Following Spinal Cord Injury in the Rat

The possibility that drugs attached to nanowires enhance their therapeutic efficacy was examined in a rat model of spinal cord injury (SCI). Three Acure compounds AP-173, AP-713 and AP-364 were tagged with TiO(2)-based nanowires (50-60 nm) and applied over the traumatized cord either 5 or 60 min after SCI in rats produced by a longitudinal incision into the right dorsal horn of the T10-11 segments under equithesin anaesthesia. Normal compounds were used for comparison. After 5 h SCI, behavioral outcome, blood-spinal cord barrier (BSCB) permeability, edema formation and cell injury were examined. Topical application of nanowired compound AP-713 (10 microg in 20 microL) when applied either 5 or 60 min after injury markedly attenuated behavioral dysfunction at 2-3 h after SCI and reduces BSCB disruption, edema formation and cord pathology at 5 h compared to other compounds. Whereas normal compounds applied at 5 min after injury (but not after 60 min) had some significant but less beneficial effects compared to their nanowired combinations. On the other hand, nanowires alone did not influence spinal cord pathology or motor function after SCI. Taken together, our results indicate that the nanowired-drug-delivery enhances the neuroprotective efficacy of drugs in SCI and reduces functional outcome compared to normal compounds even applied at a later stage following trauma, not reported earlier.