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1.
Nanomaterials (Basel) ; 10(8)2020 Aug 11.
Article in English | MEDLINE | ID: mdl-32796659

ABSTRACT

Biocompatible carbon quantum dots (CQDs) have recently attracted increased interest in biomedical imaging owing to their advantageous photoluminescence properties. Numerous precursors of fluorescent CQDs and various fabrication procedures are also reported in the literature. However; the use of concentrated mineral acids and other corrosive chemicals during the fabrication process curtails their biocompatibility and severely limits the utilization of the products in cell bio-imaging. In this study; a facile; fast; and cost-effective synthetic route is employed to fabricate CQDs from a natural organic resource; namely bread; where the use of any toxic chemicals is eliminated. Thus; the novel chemical-free technique facilitated the production of luminescent CQDs that were endowed with low cytotoxicity and; therefore; suitable candidates for bioimaging sensors. The above mentioned amorphous CQDs also exhibited fluorescence over 360-420 nm excitation wavelengths; and with a broad emission range of 360-600 nm. We have also shown that the CQDs were well internalized by muscle myoblasts (C2C12) and differentiated myotubes; the cell lines which have not been reported before.

2.
Biomed Pharmacother ; 126: 110102, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32199223

ABSTRACT

Monocytes play a crucial role in Alzheimer's disease (AD), and docosahexaenoic acid (DHA) has a neuroprotective effect for many neurodegenerative diseases. However, mechanisms that regulate monocyte and Aß protein interaction in AD and the effects of DHA on monocytes in the context of AD are not fully understood. The experiments were designed to further explore possible mechanisms of interaction between monocytes and Aß plaques. Another objective of this study was to investigate a potential mechanism for Aß-induced necroptosis involving the activation of MAPK and NF-kB signaling pathways in human THP-1 monocytes, as well as how these pathways might be modulated by DHA. Our findings indicate that Aß25-35 has a "Hormesis" effect on cell viability and necroptosis in THP-1 cells, and Aß25-35 influences THP-1 cells differentiation as analyzed by flow cytometry. Pretreatment of THP-1 monocytes with DHA effectively inhibited Aß-induced activation and markedly suppressed protein expression of necroptosis (RIPK1, RIPK3, MLKL) and pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6). Moreover, our findings indicate that Aß25-35 activated the ERK1/2 and p38 signaling pathways, but not NF-κB/p65 signaling, while pre-treatment with DHA followed by Aß25-35 treatment suppressed only ERK1/2 signaling. Further study revealed that the expression level of RIPK3 is reduced much more during coadministration with DHA and necrostatin-1 (NEC-1) than administration alone with either of them, indicating that DHA may have additional targets. Meanwhile, this finding indicates that DHA can prevent Aß-induced necroptosis of THP-1 cells via the RIPK1/RIPK3 signaling pathway. Our results also indicate that DHA treatment restored migration of THP-1 monocytes induced by Aß25-35, and DHA treatment could be a promising new therapy for AD management.


Subject(s)
Amyloid beta-Peptides/pharmacology , Docosahexaenoic Acids/pharmacology , Necroptosis/drug effects , Neuroprotective Agents/pharmacology , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Signal Transduction/drug effects , Apoptosis/drug effects , CD11b Antigen/metabolism , Cell Differentiation/drug effects , Cell Survival/drug effects , Cytokines/genetics , Cytokines/metabolism , Humans , Inflammation Mediators/metabolism , Monocytes/drug effects , Monocytes/metabolism , Neurons/drug effects , Neurons/metabolism , Peptide Fragments/pharmacology , THP-1 Cells
3.
J Med Biol Eng ; 37(1): 74-84, 2017.
Article in English | MEDLINE | ID: mdl-28286464

ABSTRACT

Intrabody communication (IBC) is a promising data communication technique for body area networks. This short-distance communication approach uses human body tissue as the medium of signal propagation. IBC is defined as one of the physical layers for the new IEEE 802.15.6 or wireless body area network (WBAN) standard, which can provide a suitable data rate for real-time physiological data communication while consuming lower power compared to that of radio-frequency protocols such as Bluetooth. In this paper, impulse radio (IR) IBC (IR-IBC) is examined using a field-programmable gate array (FPGA) implementation of an IBC system. A carrier-free pulse position modulation (PPM) scheme is implemented using an IBC transmitter in an FPGA board. PPM is a modulation technique that uses time-based pulse characteristics to encode data based on IR concepts. The transmission performance of the scheme was evaluated through signal propagation measurements of the human arm using 4- and 8-PPM transmitters, respectively. 4 or 8 is the number of symbols during modulations. It was found that the received signal-to-noise ratio (SNR) decreases approximately 8.0 dB for a range of arm distances (5-50 cm) between the transmitter and receiver electrodes with constant noise power and various signal amplitudes. The SNR for the 4-PPM scheme is approximately 2 dB higher than that for the 8-PPM one. In addition, the bit error rate (BER) is theoretically analyzed for the human body channel with additive white Gaussian noise. The 4- and 8-PPM IBC systems have average BER values of 10-5 and 10-10, respectively. The results indicate the superiority of the 8-PPM scheme compared to the 4-PPM one when implementing the IBC system. The performance evaluation of the proposed IBC system will improve further IBC transceiver design.

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