Shafiee, M. | Search bioRxiv

bioRxiv2023

A One-Step Plasma Assisted Synthesis of Gold Nanoparticles and Simultaneous Linker-Free Conjugation with Nestin: An In Vitro Study of Cellular toxicity.

We introduce a method for conjugating antigens to gold nanoparticles (GNPs) while synthesizing them using gas plasma, which eliminates the need for chemical linkers intended to facilitate the conjugation procedure for immunotherapy purposes. We report a physical approach to conjugate antigen Nestin (NES) as a marker in malignant tumors to GNPs. Two approaches were used to perform the conjugation of GNPs and NES. The first method involved using citrate to synthesize GNPs, and then NES was conjugated onto the GNPs surface by plasma. In the second method, GNPs were simultaneously synthesized and linker-freely conjugated to NES by plasma treatment. Enzyme-linked immunosorbent assay with the protocol defined in this study, Zeta-sizer, Ultraviolet-visible spectroscopy, and Transmission Electron Microscopy results confirmed NES conjugation to GNPs. In addition, the toxicity of the prepared samples was investigated in vitro using peripheral blood mononuclear cells (PBMCs) and flow cytometry, which proved the non-toxicity of the samples. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/570950v2_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1bffa43org.highwire.dtl.DTLVardef@c75811org.highwire.dtl.DTLVardef@166f4b3org.highwire.dtl.DTLVardef@4b4def_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗

bioRxiv2018

Win-concurrent sensory cues can bias decision making towards less favourable odds

Reward-related stimuli can potently influence behaviour; for example, exposure to drug-paired cues can trigger drug use and relapse in people with addictions. Psychological mechanisms that generate such outcomes likely include cue-induced cravings and attentional biases. Recent animal data suggest another candidate mechanism: reward-paired cues can enhance risky decision making, yet whether this translates to humans is unknown. Here, we examined whether sensory reward-paired cues alter decision making under uncertainty and risk, as measured respectively by the Iowa Gambling Task and a two-choice lottery task. In the cued version of both tasks, gain feedback was augmented with reward-concurrent audiovisual stimuli. Healthy human volunteers (53 males, 78 females) performed each task once, one with and the other without cues (cued IGT/uncued VGT: n = 63; uncued IGT/cued VGT: n = 68), with concurrent eye-tracking. Reward-paired cues did not affect choice on the Iowa Gambling Task. On the two-choice lottery task, the cued group displayed riskier choice and reduced sensitivity to probability information. The cued condition was associated with reduced eye fixations on probability information shown on the screen and greater pupil dilation related to decision and reward anticipation. This pupil effect was unrelated to the risk-promoting effects of cues: the degree of pupil dilation for risky versus risk-averse choices did not differ as a function of cues. Taken together, our data show that sensory reward cues can promote riskier decisions and have additional and distinct effects on arousal.\n\nSIGNIFICANCE STATEMENTAnimal data suggest that reward-paired cues can promote maladaptive reward-seeking by biasing cost-benefit decision making. Whether this finding translates to humans is unknown. We examined the effects of salient reward-paired audio-visual cues on decision making under risk and uncertainty in human volunteers. Cues had risk-promoting effects on a risky choice task and independently increased task-related arousal as measured by pupil dilation. By demonstrating risk-promoting effects of cues in human participants, our data identify a mechanism whereby cue reactivity could translate into maladaptive behavioural outcomes in people with addictions.

neuroscience↗