Stability research on polydopamine and immobilized albumin on 316L stainless steel | Regenerative Biomaterials | Oxford Academic
Abstract. In this study, the polydopamine (PDA) film was coated on polished 316Lss and then thermally treated at 150 °C (labeled as PDA-Th150), and the stabilit
Reactive oxygen species-mediated regulation of mitochondrial biogenesis in the yeast Saccharomyces cerevisiae - PubMed
Mitochondrial biogenesis is a complex process. It necessitates the participation of both the nuclear and the mitochondrial genomes. This process is highly regulated, and mitochondrial content within a cell varies according to energy demand. In the yeast Saccharomyces cerevisiae, the cAMP pathway is …
Signal transduction by reactive oxygen species - PubMed
Although historically viewed as purely harmful, recent evidence suggests that reactive oxygen species (ROS) function as important physiological regulators of intracellular signaling pathways. The specific effects of ROS are modulated in large part through the covalent modification of specific cystei …
Plants have to contend with biotic stress, such as disease, mechanical wounding, and herbivory, as well as abiotic stress, such as heat, cold, and salinity. An early warning system for these threats would prevent or reduce the damage suffered by plants. Such a warning system should allow the signal …
In situ measurements of intracellular thermal conductivity using heater-thermometer hybrid diamond nanosensors | Science Advances
Understanding heat dissipation processes at nanoscale during cellular thermogenesis is essential to clarify the relationships between the heat and biological processes in cells and organisms. A key parameter determining the heat flux inside a cell is the local thermal conductivity, a factor poorly investigated both experimentally and theoretically. Here, using a nanoheater/nanothermometer hybrid made of a polydopamine encapsulating a fluorescent nanodiamond, we measured the intracellular thermal conductivities of HeLa and MCF-7 cells with a spatial resolution of about 200 nm. The mean values determined in these two cell lines are both 0.11 ± 0.04 W m−1 K−1, which is significantly smaller than that of water. Bayesian analysis of the data suggests there is a variation of the thermal conductivity within a cell. These results make the biological impact of transient temperature spikes in a cell much more feasible, and suggest that cells may use heat flux for short-distance thermal signaling.
Regulating the absorption spectrum of polydopamine | Science Advances
Polydopamine (PDA) has been increasingly exploited as an advanced functional material, and its emergent light absorption property plays a crucial role in determining various utilizations. However, the rational design and efficient regulation of PDA absorption property remain a challenge due to the complex structure within PDA. In this work, we propose a facile method to regulate the light absorption behaviors of PDA by constructing donor-acceptor pairs within the microstructures through the chemical connections between indoledihydroxy/indolequinone and their oligomers with 2,2,6,6-tetramethylpiperidine-1-oxyl moiety. The detailed structural and spectral analysis, as well as the density functional theory simulation, further confirms the existence of donor-acceptor molecular pair structures, which could decrease the energy bandgap and increase the electron delocalization for enhancing light absorption across a broad spectrum. These rationally designed PDA nanoparticles with tunable absorption properties also show improved total photothermal effect and demonstrate excellent performances in solar desalination.
Mussel-Inspired Surface Chemistry for Multifunctional Coatings | Science
We report a method to form multifunctional polymer coatings through simple dip-coating of objects in an aqueous solution of dopamine. Inspired by the composition of adhesive proteins in mussels, we used dopamine self-polymerization to form thin, surface-adherent polydopamine films onto a wide range of inorganic and organic materials, including noble metals, oxides, polymers, semiconductors, and ceramics. Secondary reactions can be used to create a variety of ad-layers, including self-assembled monolayers through deposition of long-chain molecular building blocks, metal films by electroless metallization, and bioinert and bioactive surfaces via grafting of macromolecules.
/qresearch/ - Misuse of Israeli Surveillance Tech for Massive Violation of Human Rights
There is a criminal organization in Brazil using NSO Group's Pegasus to infect devices for hack for hire, to incite terrorism, blackmail people, produce illegal pornography and assist in assassinations. They also have other advanced malware, like UEFI implants and even persistent implants for Kindle and Raspberry Pi. Plus face/voice recognition on every camera and microphone they can get into, in public or private places.Brazil won't do anything to stop them. Only the FBI, CIA and NSA can stop them.There is also the possibility that they were engaged on the hack of Bezos' smartphone.If you know of any security researcher who wants to reverse engineer the exploits they are using, I am more than willing to help them.If you want a story about how they operate, I am willing to work with you to expose them.
Sequence-Defined DNA Amphiphiles for Drug Delivery: Synthesis and Self-Assembly | SpringerLink
DNA nanotechnology has been used to create DNA containing nanostructures with well-defined sizes and shapes—properties highly applicable to drug delivery. By appending sequence-defined hydrophobic...
Polydopamine-Assisted Surface Modification for Bone Biosubstitutes
Polydopamine (PDA) prepared in the form of a layer of polymerized dopamine (DA) in a weak alkaline solution has been used as a versatile biomimetic surface modifier as well as a broadly used immobilizing macromolecule. This review mainly discusses the progress of biomaterial surface modification inspired by the participation of PDA in bone tissue engineering. A comparison between PDA-assisted coating techniques and traditional surface modification applied to bone tissue engineering is first presented. Secondly, the chemical composition and the underlying formation mechanism of PDA coating layer as a unique surface modifier are interpreted and discussed. Furthermore, several typical examples are provided to evidence the importance of PDA-assisted coating techniques in the construction of bone biosubstitutes and the improvement of material biocompatibility. Nowadays, the application of PDA as a superior surface modifier in multifunctional biomaterials is drawing tremendous interests in bone tissue scaffolds to promote the osteointegration for bone regeneration.
Altmetric – Glucose oxidase and polydopamine functionalized iron oxide nanoparticles: combination of the photothermal effect and reactive oxygen species generation for dual-modality selective cancer therapy
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Circadian clocks in human red blood cells - PubMed
Circadian (∼24 hour) clocks are fundamentally important for coordinated physiology in organisms as diverse as cyanobacteria and humans. All current models of the molecular circadian clockwork in eukaryotic cells are based on transcription-translation feedback loops. Non-transcriptional mechanisms in …
Co-delivery of doxorubicin and DNAzyme using ZnO@polydopamine core-shell nanocomposites for chemo/gene/photothermal therapy - ScienceDirect
Multi-modal nanomedicines that synergistically combine chemo-, gene-, and photothermal therapy have shown great potential for cancer treatment. In thi…
The PI3K-AKT-FoxO pathway is integral to lifespan regulation in lower organisms and essential for the stability of long-lived cells in mammals. Here, we report the impact of combined FoxO1, 3, and 4 deficiencies on mammalian brain physiology with a particular emphasis on the study of the neural stem …
Current strategies to enhance the targeting of polydopamine-based platforms for cancer therapeutics: Journal of Drug Targeting: Vol 28, No 2
(2020). Current strategies to enhance the targeting of polydopamine-based platforms for cancer therapeutics. Journal of Drug Targeting: Vol. 28, No. 2, pp. 142-153.
The University of Colorado Department of Obstetrics and Gynecology is committed producing innovative research and educating future clinicians and leaders in the areas of women's health, including gynecological cancer, reproductive medicine, urogynecology, transgender health, family planning and maternal-fetal medicine.
Gastrointestinal synthetic epithelial linings | Science Translational Medicine
Orally delivered drugs are primarily absorbed in the small intestine, which is also the major site of nutrient absorption. Li and colleagues developed a versatile polydopamine-based solution that can coat and polymerize in situ in the small intestine. The synthetic coating adhered to pig and human tissue ex vivo, remaining stable for up to 24 hours. When administered to pigs endoscopically, polydopamine solution with suspended β-galactosidase increased digestive enzyme activity, whereas solution with embedded polydopamine nano–cross-linkers created a coating with transient barrier function that prevented glucose absorption. Encapsulating the anthelmintic drug praziquantel in polydopamine solution enhanced intestinal retention and adsorption in pigs, demonstrating the potential utility of this biomaterial for drug delivery. Epithelial tissues line the organs of the body, providing an initial protective barrier as well as a surface for nutrient and drug absorption. Here, we identified enzymatic components present in the gastrointestinal epithelium that can serve as selective means for tissue-directed polymerization. We focused on the small intestine, given its role in drug and nutrient absorption and identified catalase as an essential enzyme with the potential to catalyze polymerization and growth of synthetic biomaterial layers. We demonstrated that the polymerization of dopamine by catalase yields strong tissue adhesion. We characterized the mechanism and specificity of the polymerization in segments of the gastrointestinal tracts of pigs and humans ex vivo. Moreover, we demonstrated proof of concept for application of these gastrointestinal synthetic epithelial linings for drug delivery, enzymatic immobilization for digestive supplementation, and nutritional modulation through transient barrier formation in pigs. This catalase-based approach to in situ biomaterial generation may have broad indications for gastrointestinal applications.
Preclinical development of Ramizol, an antibiotic belonging to a new class, for the treatment of Clostridium difficile colitis - PubMed
Antibiotic-resistant bacteria is a major threat to human health and is predicted to become the leading cause of death from disease by 2050. Despite the recent resurgence of research and development in the area, few antibiotics have reached the market, with most of the recently approved antibiotics c …
Bio-Applications of Multifunctional Melanin Nanoparticles: From Nanomedicine to Nanocosmetics - PubMed
Bioinspired nanomaterials are ideal components for nanomedicine, by virtue of their expected biocompatibility or even complete lack of toxicity. Natural and artificial melanin-based nanoparticles (MNP), including polydopamine nanoparticles (PDA NP), excel for their extraordinary combination of addit …