212 resultados para Lauren McCarthy
Resumo:
Americans have been shown to attribute greater intentionality to immoral than to amoral actions in cases of causal deviance, that is, cases where a goal is satisfied in a way that deviates from initially planned means (e.g., a gunman wants to hit a target and his hand slips, but the bullet ricochets off a rock into the target). However, past research has yet to assess whether this asymmetry persists in cases of extreme causal deviance. Here, we manipulated the level of mild to extreme causal deviance of an immoral versus amoral act. The asymmetry in attributions of intentionality was observed at all but the
most extreme level of causal deviance, and, as we hypothesized, was mediated by attributions of Blame/credit and judgments of action performance. These findings are discussed as they support a multiple-concepts interpretation of the asymmetry, wherein blame renders a naïve concept of intentional action (the outcome matches the intention) more salient than a composite concept (the outcome matches the intention and was brought about by planned means), and in terms of their implications for cross-cultural research on judgments of agency.
Resumo:
We report the formulation of novel composite nanoparticles that combine the high transfection efficiency of cationic peptide-DNA nanoparticles with the biocompatibility and prolonged delivery of polylactic acid–polyethylene glycol (PLA-PEG). The cationic cell-penetrating peptide RALA was used to condense DNA into nanoparticles that were encapsulated within a range of PLA-PEG copolymers. The composite nanoparticles produced exhibited excellent physicochemical properties including size <200 nm and encapsulation efficiency >80%. Images of the composite nanoparticles obtained with a new transmission electron microscopy staining method revealed the peptide-DNA nanoparticles within the PLA-PEG matrix. Varying the copolymers modulated the DNA release rate >6 weeks in vitro. The best formulation was selected and was able to transfect cells while maintaining viability. The effect of transferrin-appended composite nanoparticles was also studied. Thus, we have demonstrated the manufacture of composite nanoparticles for the controlled delivery of DNA.
Resumo:
This chapter examines key concepts with respect to cancer gene therapy and the current issues with respect to non-viral delivery. The biological and molecular barriers that need to be overcome before effective non-viral delivery systems can be appropriately designed for oncology applications are highlighted and ways to overcome these are discussed. Strategies developed to evade the immune response are also described and targeted gene delivery is examined with the most effective strategies highlighted. Finally, this chapter proposes a new way forward based on a growing body of evidence that supports a multifunctional delivery approach involving the creation of vectors, with a unique molecular architecture designed using a bottom-up approach.
Resumo:
The aim of this study was to increase understanding of the mechanism and dominant drivers influencing phase separation during ram extrusion of calcium phosphate (CaP) paste for orthopaedic applications. The liquid content of extrudate was determined, and the flow of liquid and powder phases within the syringe barrel during extrusion were observed, subject to various extrusion parameters. Increasing the initial liquid-to-powder mass ratio, LPR, (0.4-0.45), plunger rate (5-20 mm/min), and tapering the barrel exit (45°-90°) significantly reduced the extent of phase separation. Phase separation values ranged from (6.22 ± 0.69 to 18.94 ± 0.69 %). However altering needle geometry had no significant effect on phase separation. From powder tracing and liquid content determination, static zones of powder and a non-uniform liquid distribution was observed within the barrel. Measurements of extrudate and paste LPR within the barrel indicated that extrudate LPR remained constant during extrusion, while LPR of paste within the barrel decreased steadily. These observations indicate the mechanism of phase separation was located within the syringe barrel. Therefore phase separation can be attributed to either; (1) the liquid being forced downstream by an increase in pore pressure as a result of powder consolidation due to the pressure exerted by the plunger or (2) the liquid being drawn from paste within the barrel, due to suction, driven by dilation of the solids matrix at the barrel exit. Differentiating between these two mechanisms is difficult; however results obtained suggest that suction is the dominant phase separation mechanism occurring during extrusion of CaP paste.
Resumo:
The discovery of a sensory organ, the Schwabe organ, was recently reported as a unifying feature of chitons in the order Lepidopleurida. It is a patch of pigmented tissue located on the roof of the pallial cavity, beneath the velum on either side of the mouth. The epithelium is densely innervated and contains two types of potential sensory cells. As the function of the Schwabe organ remains unknown, we have taken a cross-disciplinary approach, using anatomical, histological and behavioural techniques to understand it. In general, the pigmentation that characterises this sensory structure gradually fades after death; however, one particular concentrated pigment dot persists. This dot is positionally homologous to the larval eye in chiton trochophores, found in the same neuroanatomical location, and furthermore the metamorphic migration of the larval eye is ventral in species known to possess Schwabe organs. Here we report the presence of a discrete subsurface epithelial structure in the region of the Schwabe organ in Leptochiton asellus that histologically resembles the chiton larval eye. Behavioural experiments demonstrate that Leptochiton asellus with intact Schwabe organs actively avoid an upwelling light source, while Leptochiton asellus with surgically ablated Schwabe organs and a control species lacking the organ (members of the other extant order, Chitonida) do not (Kruskal-Wallis, H = 24.82, df = 3, p < 0.0001). We propose that the Schwabe organ represents the adult expression of the chiton larval eye, being retained and elaborated in adult lepidopleurans.
Resumo:
We describe, for the first time the use of hydrogel-forming microneedle (MN) arrays for minimally-invasive extraction and quantification of drug substances and glucose from skin in vitro and in vivo. MN prepared from aqueous blends of hydrolysed poly(methyl-vinylether-co-maleic anhydride) (11.1% w/w) and poly(ethyleneglycol) 10,000 daltons (5.6% w/w) and crosslinked by esterification swelled upon skin insertion by uptake of fluid. Post-removal, theophylline and caffeine were extracted from MN and determined using HPLC, with glucose quantified using a proprietary kit. In vitro studies using excised neonatal porcine skin bathed on the underside by physiologically-relevant analyte concentrations showed rapid (5 min) analyte uptake. For example, mean concentrations of 0.16 μg/mL and 0.85 μg/mL, respectively, were detected for the lowest (5 μg/mL) and highest (35 μg/mL) Franz cell concentrations of theophylline after 5 min insertion. A mean concentration of 0.10 μg/mL was obtained by extraction of MN inserted for 5 min into skin bathed with 5 μg/mL caffeine, while the mean concentration obtained by extraction of MN inserted into skin bathed with 15 μg/mL caffeine was 0.33 μg/mL. The mean detected glucose concentration after 5 min insertion into skin bathed with 4 mmol/L was 19.46 nmol/L. The highest theophylline concentration detected following extraction from a hydrogel-forming MN inserted for 1 h into the skin of a rat dosed orally with 10 mg/kg was of 0.363 μg/mL, whilst a maximum concentration of 0.063 μg/mL was detected following extraction from a MN inserted for 1 h into the skin of a rat dosed with 5 mg/kg theophylline. In human volunteers, the highest mean concentration of caffeine detected using MN was 91.31 μg/mL over the period from 1 to 2 h post-consumption of 100 mg Proplus® tablets. The highest mean blood glucose level was 7.89 nmol/L detected 1 h following ingestion of 75 g of glucose, while the highest mean glucose concentration extracted from MN was 4.29 nmol/L, detected after 3 hours skin insertion in human volunteers. Whilst not directly correlated, concentrations extracted from MN were clearly indicative of trends in blood in both rats and human volunteers. This work strongly illustrates the potential of hydrogel-forming MN in minimally-invasive patient monitoring and diagnosis. Further studies are now ongoing to reduce clinical insertion times and develop mathematical algorithms enabling determination of blood levels directly from MN measurements.
Resumo:
Designer biopolymers (DBPs) represent state of the art genetically engineered biomacromolecules designed to condense plasmid DNA, and overcome intra- and extra- cellular barriers to gene delivery. Three DBPs were synthesized, each with the tumor molecular targeting peptide-1 (TMTP-1) motif to specifically target metastases. Each DBP was complexed with a pEGFP-N1 reporter plasmid to permit physiochemical and biological assay analysis. Results indicated that two of the biopolymers (RMHT and RM3GT) effectively condensed pEGFP-N1 into cationic nanoparticles< 100nm and were capable of transfecting PC-3 metastatic prostate cancer cells. Conversely the anionic RMGT DBP nanoparticles could not transfect PC-3 cells. RMHT and RM3GT nanoparticles were stable in the presence of serum and protected the cargo from degradation. Additionally it was concluded that cell viability could recover post-transfection with these DBPs, which were less toxic than the commercially available transfection reagent Lipofectamine® 2000. With both DBPs, a higher transfection efficacy was observed in PC-3 cells than in the moderately metastatic, DU145, and normal, PNT2-C2, cell lines. Blocking of the TMTP-1 receptors inhibited gene transfer indicating internalization via this receptor. In conclusion RMHT and RM3GT are fully functional DBPs that address major obstacles to gene delivery and target metastatic cells expressing the TMTP-1 receptor.
Resumo:
We describe, for the first time, hydrogel-forming microneedle (MN) arrays for minimally-invasive extraction and quantification of lithium in vitro and in vivo. MN arrays, prepared from aqueous blends of hydrolysed poly(methyl-vinylether-co-maleic anhydride) and crosslinked by poly(ethyleneglycol), imbibed interstitial fluid (ISF) upon skin insertion. Such MN were always removed intact. In vitro, mean detected lithium concentrations showed no significant difference following 30 min MN application to excised neonatal porcine skin for lithium citrate concentrations of 0.9 and 2 mmol/l. However, after 1 h application, the mean lithium concentrations extracted were significantly different, being appropriately concentration-dependent. In vivo, rats were orally dosed with lithium citrate equivalent to 15 mg/kg and 30 mg/kg lithium carbonate, respectively. MN arrays were applied 1 h after dosing and removed 1 h later. The two groups, having received different doses, showed no significant difference between lithium concentrations in serum or MN. However, the higher dosed rats demonstrated a lithium concentration extracted from MN arrays equivalent to a mean increase of 22.5 % compared to rats which received the lower dose. Hydrogel-forming MN clearly have potential as a minimally-invasive tool for lithium monitoring in out-patient settings. We will now focus on correlation of serum and MN lithium concentrations.
Resumo:
Transdermal drug delivery is an attractive route of drug administration, however there are relatively few marketed transdermal products. To increase delivery across the skin, strategies to enhance skin permeability are widely investigated, with microneedles demonstrating particular promise. Hydrogel-forming microneedles are inserted into the skin, and following dissolution of a drug loaded reservoir and movement of the drug through the created channels, the microneedle array is removed intact, and can then be readily and safely discarded. This study presents the formulation and evaluation of an integrated microneedle patch containing the Alzheimer's drug, donepezil hydrochloride. The integrated patch consisted of hydrogel-forming microneedles in combination with a donepezil hydrochloride containing film. Formulation and characterisation of plasticised films, prepared from poly(vinylpyrrolidone) or poly (methyl vinyl ether co-maleic anhydride/acid) (Gantrez(®)) polymers, is presented. Furthermore, in vitro permeation of donepezil hydrochloride across neonatal porcine skin from the patches was investigated, with 854.71 μg ± 122.71 μg donepezil hydrochloride delivered after 24 h, using the optimum patch formulation. Following administration of the patch to an animal model, plasma concentrations of 51.8 ± 17.6 ng/mL were obtained, demonstrating the success of this delivery platform for donepezil hydrochloride.
Resumo:
In a recent article (Astuti & Bloch, 2015), cognitive anthropologists Rita Astuti and Maurice Bloch claim that the Malagasy are ambivalent as to whether considerations of intentionality are relevant to moral judgments concerning incest and its presumed catastrophic consequences: when making moral judgments about those who commit incest, the Malagasy take into account whether the incest is intentional or not, but, when making moral judgments relating to incest’s catastrophic consequences, they do not take intentionality into account. Astuti & Bloch explain the irrelevance of intentionality in terms of incest entailing such a fundamental attack on the transcendental social order that the Malagasy become dumbfounded and leave aside considerations of intentionality. Finally, they claim that a similar dumbfound reaction is what is involved in the moral dumbfounding concerning incest that social psychologist Jonathan Haidt has found in the US. In this article, we argue that (i) Astuti & Bloch are unclear about many aspects of their claims (in particular, about the moral judgments at stake), (ii) they do not provide sufficient evidence that considerations of intentionality are deemed irrelevant to moral judgments relating to incest’s presumed catastrophic consequences (and hence for the claim that the Malagasy are ambivalent), (iii) their hypothesis that conceiving of incest as an attack on the transcendental social renders considerations of intentionality irrelevant lacks coherence, and (iv) the extension of their explanatory account to the moral dumfounding of American students in Haidt’s well-known scenario of intentional incest is unwarranted.
Resumo:
Powder-based inkjet three-dimensional printing (3DP) to fabricate pre-designed 3D structures has drawn increasing attention. However there are intrinsic limitations associated with 3DP technology due to the weak bonding within the printed structure, which significantly compromises its mechanical integrity. In this study, calcium sulphate ceramic structures demonstrating a porous architecture were manufactured using 3DP technology and subsequently post-processed with a poly (ε-caprolactone) (PCL) coating. PCL concentration, immersion time, and number of coating layers were the principal parameters investigated and improvement in compressive properties was the measure of success. Interparticle spacing within the 3DP structures were successfully filled with PCL material. Consequently the compressive properties, wettability, morphology, and in vitro resorption behaviour of 3DP components were significantly augmented. The average compressive strength, Young’s modulus, and toughness increased 217%, 250%, and 315%, following PCL coating. Addition of a PCL surface coating provided long-term structural support to the host ceramic material, extending the resorption period from less than 7 days to a minimum of 56 days. This study has demonstrated that application of a PCL coating onto a ceramic 3DP structure was a highly effective approach to addressing some of the limitations of 3DP manufacturing and allows this advanced technology to be potentially used in a wider range of applications.
Resumo:
Microneedle technology provides the opportunity for the delivery of DNA therapeutics by a non-invasive, patient acceptable route. To deliver DNA successfully requires consideration of both extra and intracellular biological barriers. In this study we present a novel two tier platform; i) a peptide delivery system, termed RALA, that is able to wrap the DNA into nanoparticles, protect the DNA from degradation, enter cells, disrupt endosomes and deliver the DNA to the nucleus of cells ii) a microneedle (MN) patch that will house the nanoparticles within the polymer matrix, breach the skin's stratum corneum barrier and dissolve upon contact with skin interstitial fluid thus releasing the nanoparticles into the skin. Our data demonstrates that the RALA is essential for preventing DNA degradation within the poly(vinylpyrrolidone) (PVP) polymer matrix. In fact the RALA/DNA nanoparticles (NPs) retained functionality when in the MN arrays after 28days and over a range of temperatures. Furthermore the physical strength and structure of the MNs was not compromised when loaded with the NPs. Finally we demonstrated the effectiveness of our MN-NP platform in vitro and in vivo, with systemic gene expression in highly vascularised regions. Taken together this 'smart-system' technology could be applied to a wide range of genetic therapies.