Identification of novel ‘inks’ for 3D printing using high throughput screening: bioresorbable photocurable polymers for controlled drug delivery

A robust discovery methodology is presented to identify novel biomaterials suitable for 3D printing. Currently the application of Additive Manufacturing is limited by the availability of functional inks, especially in the area of biomaterials-this method tackles this problem for the first time allowing hundreds of formulations to be readily assessed. Several functional properties, including the release of an antidepressive drug (paroxetine), cytotoxicity and printability are screened for 253 new ink formulations in a high-throughput format as well as mechanical properties. The selected candidates with the desirable properties are successfully scaled up using 3D printing into a range of objects architectures. A full drug release study, degradability and tensile modulus experiments are presented on a simple architecture to validating the suitability of this methodology to identify printable inks for 3D printing devices with bespoke properties

Effects of the cannabinoid CB1 agonist ACEA on salicylate ototoxicity, hyperacusis and tinnitus in guinea pigs

Cannabinoids have been suggested as a therapeutic target for a variety of brain disorders. Despite the presence of their receptors throughout the auditory system, little is known about how cannabinoids affect auditory function. We sought to determine whether administration of arachidonyl-2′-chloroethylamide (ACEA), a highly-selective CB1 agonist, could attenuate a variety of auditory effects caused by prior administration of salicylate, and potentially treat tinnitus. We recorded cortical resting-state activity, auditory-evoked cortical activity and auditory brainstem responses (ABRs), from chronically-implanted awake guinea pigs, before and after salicylate + ACEA. Salicylate-induced reductions in click-evoked ABR amplitudes were smaller in the presence of ACEA, suggesting that the ototoxic effects of salicylate were less severe. ACEA also abolished salicylate-induced changes in cortical alpha band (6-10 Hz) oscillatory activity. However, salicylate-induced increases in cortical evoked activity (suggestive of the presence of hyperacusis) were still present with salicylate + ACEA. ACEA administered alone did not induce significant changes in either ABR amplitudes or oscillatory activity, but did increase cortical evoked potentials. Furthermore, in two separate groups of non-implanted animals, we found no evidence that ACEA could reverse behavioural identification of salicylate- or noise-induced tinnitus. Together, these data suggest that while ACEA may be potentially otoprotective, selective CB1 agonists are not effective in diminishing the presence of tinnitus or hyperacusis

Alternative and Renewable Energy

Energy, in its current state, is a finite resource that will not last for generations to come. This project investigates existing research on several renewable energy alternatives, including nuclear, hydroelectric, natural gas, biofuels, and more, as well as providing a potential method of combining solar and wind energy harvesting techniques for increased efficiency. Finally, the social effects of renewable energy on health, the environment, and politics are considered, and an outlook for the future is included

Insights on activity and stability of subtilisin E towards guanidinium chloride and sodium dodecylsulfate

A subtilisin E variant (M4) showing high activity and resistance towards guanidinium chloride (GdmCl) and sodium dodecylsulfate (SDS) was previously identified after three rounds of directed evolution [Li et al., ChemBioChem 2012, 13(5), 691–699.]. In this report, 10 additional positions, identified during directed subtilisin E evolution, were saturated on the previously reported SeSaM1-5 variant (S62/A153/G166/I205). Screening confirmed that chaotolerant variants included amino acid substitutions either in the active site, or the substrate binding pocket. Two variants, M5 (S62I/A153V/G166S/T224A/T240S) and M6 (S62I/A153V/G166S/I205V/N218S/T224A) were finally generated to maximize activity and stability in the presence of GdmCl or SDS. The inactivation concentration (IC50) of M6 using Suc-AAPF-pNA as substrate was significantly increased compared to M4 in the presence of GdmCl (IC50 (M4): 2.7 M; IC50 (M6): 4.6 M) and SDS (IC50 (M4): 1.5%; IC50 (M6): 4.0%). The half-life in 5 M GdmCl was also significantly improved for M6 compared to M4 (t 1/2 (M4): 2 min; t 1/2 (M6): 15 min). M5 retained resistance towards GdmCl or SDS as in M4. The activity of M5 towards a complex protein substrate (Azocasein) was increased by ∼1.5 fold compared to M4 and M6. Circular dichroism (CD) analysis for subtilisin E wild type (WT) and three variants (M4, M5 and M6) indicated that secondary structures of all variants including wild type at 1–2 M GdmCl (except M4) were not significantly perturbed, with unfolding occurring for WT and all three variants above 3 M GdmCl. In SDS, the secondary structures of WT and all three variants remained intact at concentrations of 0.5 to 2.0% (w/v) SDS. Results suggest that subtilisin E inactivation occurred most likely due to inhibitory effect, since a general unfolding of the enzyme was not observed through circular dichroism. Such inhibition could be avoided by limiting the access of GdmCl and SDS to the active site and/or to residues involved in substrate binding