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Discover Nano Apr 2024Modern imaging strategies are paramount to studying living systems such as cells, bacteria, and fungi and their response to pathogens, toxicants, and nanomaterials (NMs)... (Review)
Review
Modern imaging strategies are paramount to studying living systems such as cells, bacteria, and fungi and their response to pathogens, toxicants, and nanomaterials (NMs) as modulated by exposure and environmental factors. The need to understand the processes and mechanisms of damage, healing, and cell survivability of living systems continues to motivate the development of alternative imaging strategies. Of particular interest is the use of label-free techniques (microscopy procedures that do not require sample staining) that minimize interference of biological processes by foreign marking substances and reduce intense light exposure and potential photo-toxicity effects. This review focuses on the synergic capabilities of atomic force microscopy (AFM) as a well-developed and robust imaging strategy with demonstrated applications to unravel intimate details in biomedical applications, with the label-free, fast, and enduring Holotomographic Microscopy (HTM) strategy. HTM is a technique that combines holography and tomography using a low intensity continuous illumination laser to investigate (quantitatively and non-invasively) cells, microorganisms, and thin tissue by generating three-dimensional (3D) images and monitoring in real-time inner morphological changes. We first review the operating principles that form the basis for the complementary details provided by these techniques regarding the surface and internal information provided by HTM and AFM, which are essential and complimentary for the development of several biomedical areas studying the interaction mechanisms of NMs with living organisms. First, AFM can provide superb resolution on surface morphology and biomechanical characterization. Second, the quantitative phase capabilities of HTM enable superb modeling and quantification of the volume, surface area, protein content, and mass density of the main components of cells and microorganisms, including the morphology of cells in microbiological systems. These capabilities result from directly quantifying refractive index changes without requiring fluorescent markers or chemicals. As such, HTM is ideal for long-term monitoring of living organisms in conditions close to their natural settings. We present a case-based review of the principal uses of both techniques and their essential contributions to nanomedicine and nanotoxicology (study of the harmful effects of NMs in living organisms), emphasizing cancer and infectious disease control. The synergic impact of the sequential use of these complementary strategies provides a clear drive for adopting these techniques as interdependent fundamental tools.
PubMed: 38594446
DOI: 10.1186/s11671-024-04003-x -
Cureus Mar 2024Introduction Skin photoaging is caused by prolonged exposure to sunlight, particularly ultraviolet rays (UV). High cumulative levels of UV radiation may cause burning,...
Introduction Skin photoaging is caused by prolonged exposure to sunlight, particularly ultraviolet rays (UV). High cumulative levels of UV radiation may cause burning, photoallergic or phototoxic reactions, pigmentary changes, photoaging, and even immunosuppression and skin cancers. Therefore, this study aims to assess knowledge, attitude, reception, and preventive practices towards skin photoaging among the Jazan general population in Saudi Arabia and its determinants. Methods A descriptive cross-sectional study was conducted among the general population of Jazan, Saudi Arabia, who were aged 18 years and above and agreed to participate in the study. The calculated minimum sample size was 385. An online, semi-structured, self-administered questionnaire was distributed conveniently in Google Forms through social media platforms. It included four sections: The first section was about sociodemographic characteristics. The second section assessed the smoking, exercise, and healthy diet behavior of participants and the use of sunscreen. The third section assessed the knowledge regarding the photoaging process and its preventive measures utilization using three-point Likert scale questions. The fourth section assessed attitudes towards the photoaging process and its preventive measures through three-point Likert scales. Results The study included 452, of which 243 (53.76%) were aged 18-30 years, 258 (57.08%) were females, and 272 (60.18%) had white skin color. Approximately 417 (92.26%) were nonsmokers. Sixty-eight percent (372) spent 1-3 hours in the sun. Social media was the primary source of information on photoaging 81 (17.92%). Around 234 (51.77%) defined photoaging correctly. Regarding sunscreen usage, 58 (12.83%) always use sunscreen, and 177 (39.16%) never use it. However, 191 (42.26%) recognized the correct sunscreen application. Approximately 233 (51.5%) and 240 (53.1%) of respondents had fair knowledge and a positive attitude regarding photoaging and sunscreen use. Being female, pursuing university and postgraduate education, and taking information on photoaging from a physician were linked to a higher knowledge of photoaging (p<0.05). Participants who never use sunscreen had lower knowledge than those who always use it (p<0.001). None of the demographic factors was associated with the attitude towards sunscreen use (p>0.05). Conclusion There is a substantial gap in knowledge and preventive practices related to skin photoaging among the Jazan general population in Saudi Arabia. Gender, education level, and information sources influence knowledge levels. Targeted educational interventions are needed to enhance awareness and promote healthier practices, particularly sun exposure and photoaging prevention.
PubMed: 38586780
DOI: 10.7759/cureus.55710 -
Journal of Inorganic Biochemistry Jul 2024Trinuclear ruthenium(II) polypyridyl complexes anchored to benzimidazole-triazine / trisamine scaffolds were investigated as photosensitizers for photodynamic therapy....
Trinuclear ruthenium(II) polypyridyl complexes anchored to benzimidazole-triazine / trisamine scaffolds were investigated as photosensitizers for photodynamic therapy. The trinuclear complexes were noted to produce a significant amount of singlet oxygen in both DMF and aqueous media, are photostable and show appreciable emission quantum yields (ɸ). In our experimental setting, despite the moderate phototoxic activity in the HeLa cervical cancer cell line, the phototoxic indices (PI) of the trinuclear complexes are superior relative to the PIs of a clinically approved photosensitizer, Photofrin®, and the pro-drug 5-aminolevulinic acid (PI: >7 relative to PI: >1 and PI: 4.4 for 5-aminolevulinic acid and Photofrin®, respectively). Furthermore, the ruthenium complexes were noted to show appreciable long-term cytotoxicity upon light irradiation in HeLa cells in a concentration-dependent manner. Consequently, this long-term activity of the ruthenium(II) polypyridyl complexes embodies their ability to reduce the probability of the recurrence of cervical cancer. Taken together, this presents a strong motivation for the development of polymetallic complexes as anticancer agents.
Topics: Humans; Photosensitizing Agents; HeLa Cells; Uterine Cervical Neoplasms; Ruthenium; Female; Coordination Complexes; Photochemotherapy; Antineoplastic Agents; Pyridines; Singlet Oxygen
PubMed: 38581803
DOI: 10.1016/j.jinorgbio.2024.112545 -
RSC Chemical Biology Apr 2024Ruthenium(ii) complexes are attracting significant research attention as a promising class of photosensitizers (PSs) in photodynamic therapy (PDT). Having previously...
Ruthenium(ii) complexes are attracting significant research attention as a promising class of photosensitizers (PSs) in photodynamic therapy (PDT). Having previously reported the synthesis of two novel Ru(ii)-polypyridyl-1,8-naphthalimide Tröger's base compounds 1 and 2 with interesting photophysical properties, where the emission from either the Ru(ii) polypyridyl centres or the naphthalimide moieties could be used to monitor binding to nucleic acids, we sought to use these compounds to investigate further and in more detail their biological profiling, which included unravelling their mechanism of cellular uptake, cellular trafficking and cellular responses to photoexcitation. Here we demonstrate that these compounds undergo rapid time dependent uptake in HeLa cells that involved energy dependent, caveolae and lipid raft-dependent mediated endocytosis, as demonstrated by confocal imaging, and transmission and scanning electron microscopy. Following endocytosis, both compounds were shown to localise to mostly lysosomal and Golgi apparatus compartments with some accumulation in mitochondria but no localisation was found to the nucleus. Upon photoactivation, the compounds increased ROS production and induced ROS-dependent apoptotic cell death. The photo-activated compounds subsequently induced DNA damage and altered tubulin, but not actin structures, which was likely to be an indirect effect of ROS production and induced apoptosis. Furthermore, by changing the concentration of the compounds or the laser used to illuminate the cells, the mechanism of cell death could be changed from apoptosis to necrosis. This is the first detailed biological study of Ru(ii)-polypyridyl Tröger's bases and clearly suggests caveolae-dependent endocytosis is responsible for cell uptake - this may also explain the lack of nuclear uptake for these compounds and similar results observed for other Ru(ii)-polypyridyl complexes. These conjugates are potential candidates for further development as PDT agents and may also be useful in mechanistic studies on cell uptake and trafficking.
PubMed: 38576718
DOI: 10.1039/d3cb00206c -
RSC Advances Mar 2024Conventional Au nanomaterial synthesis typically necessitates the involvement of extensive surfactants and reducing agents, leading to a certain amount of chemical waste...
Conventional Au nanomaterial synthesis typically necessitates the involvement of extensive surfactants and reducing agents, leading to a certain amount of chemical waste and biological toxicity. In this study, we innovatively employed ultra-small graphene oxide as a reducing agent and surfactant for the generation of small Au nanoparticles under ultraviolet irradiation (UV) at ambient conditions. After ultra-small GO-Au seeds were successfully synthesized, we fabricated small star-like Au nanoparticles on the surface of GO, in which GO effectively prevented Austar from aggregation. To further use GO-Austar for cancer PTT therapy, through the modification of reduced human serum albumin-folic acid conjugate (rHSA-FA) and loading IR780, the final probe GO-Austar@rHSA-FA@IR780 was prepared. The prepared probe showed excellent biocompatibility and superb phototoxicity towards MGC-803 cells . , the final probe dramatically increased tumor temperature up to 58.6 °C after 5 minutes of irradiation by an 808 nm laser, significantly inhibiting tumor growth and nearly eradicating subcutaneous tumors in mice. This research provides a novel and simple method for the synthesis of GO-Au nanocomposites, showcasing significant potential in biological applications.
PubMed: 38567330
DOI: 10.1039/d4ra00742e -
Neurophotonics Apr 2024Optical imaging has accelerated neuroscience in recent years. Genetically encoded fluorescent activity sensors of calcium, neurotransmitters, and voltage are commonly...
SIGNIFICANCE
Optical imaging has accelerated neuroscience in recent years. Genetically encoded fluorescent activity sensors of calcium, neurotransmitters, and voltage are commonly used for optical recording of neuronal activity. However, fluorescence imaging is limited to superficial regions for activity imaging, due to photon scattering and absorbance. Bioluminescence imaging offers a promising alternative for achieving activity imaging in deeper brain regions without hardware implanted within the brain. Bioluminescent reporters can be genetically encoded and produce photons without external excitation. The use of enzymatic photon production also enables prolonged imaging sessions without the risk of photobleaching or phototoxicity, making bioluminescence suitable for non-invasive imaging of deep neuronal populations.
AIM
To facilitate the adoption of bioluminescent activity imaging, we sought to develop a low cost, simple method that simulates conditions to optimize imaging parameters for determining optimal exposure times and optical hardware configurations to determine what frame rates can be captured with an individual lab's imaging hardware with sufficient signal-to-noise ratios without the use of animals prior to starting an experiment.
APPROACH
We developed an assay for modeling optical conditions with a brain tissue phantom paired with engineered cells that produce bioluminescence. We then used this assay to limit-test the detection depth versus maximum frame rate for bioluminescence imaging at experimentally relevant tissue depths using off-the-shelf imaging hardware.
RESULTS
We developed an assay for modeling optical conditions with a brain tissue phantom paired with engineered cells that produce bioluminescence. With this method, we demonstrate an effective means for increasing the utility of bioluminescent tools and lowering the barrier to adoption of bioluminescence activity imaging.
CONCLUSIONS
We demonstrated an improved method for optimizing imaging parameters for activity imaging with bioluminescent sensors.
PubMed: 38550774
DOI: 10.1117/1.NPh.11.2.024206 -
International Journal of Molecular... Mar 2024Nanoparticles (NPs) represent a potential optoelectronic source capable of significantly boosting hydrogen production; however, their inevitable cytotoxicity may lead to...
Nanoparticles (NPs) represent a potential optoelectronic source capable of significantly boosting hydrogen production; however, their inevitable cytotoxicity may lead to oxidative damage of bacterial cell membranes. In this study, we employed non-photosynthetic K-12 as a model organism and utilized self-assembled cadmium sulfide (CdS) nanoparticles to construct a low-toxicity and hydrogen-production-enhancing self-photosensitive hybrid system. To mitigate the cytotoxicity of CdS NPs and synthesize biocompatible CdS NPs on the cell surface, we employed engineered (/OE) for bioremediation, achieving this goal through the overexpression of the peroxidase enzyme (EfeB). A comparative analysis with -CdS revealed a significant downregulation of genes encoding oxidative stress proteins in /OE-CdS post-irradiation. Atomic force microscopy (AFM) confirmed the stability of bacterial cell membranes. Due to the enhanced stability of the cell membrane, the hydrogen yield of the /OE-CdS system increased by 1.3 times compared to the control, accompanied by a 49.1% reduction in malondialdehyde (MDA) content. This study proposes an effective strategy to alleviate the toxicity of mixed biological nanoparticle systems and efficiently harness optoelectronic electrons, thereby achieving higher hydrogen production in bioremediation.
Topics: Humans; Escherichia coli; Escherichia coli K12; Nanoparticles; Dermatitis, Phototoxic; Sulfides; Hydrogen; Cadmium Compounds
PubMed: 38542058
DOI: 10.3390/ijms25063085 -
Scientific Reports Mar 2024Light is known to induce retinal damage affecting photoreceptors and retinal pigment epithelium. For polychromatic light, the blue part of the spectrum is thought to be...
Light is known to induce retinal damage affecting photoreceptors and retinal pigment epithelium. For polychromatic light, the blue part of the spectrum is thought to be the only responsible for photochemical damage, leading to the establishment of a phototoxicity threshold for blue light (445 nm). For humans it corresponds to a retinal dose of 22 J/cm. Recent studies on rodents and non-human primates suggested that this value is overestimated. In this study, we aim at investigating the relevance of the current phototoxicity threshold and at providing new hints on the role of the different components of the white light spectrum on phototoxicity. We use an in vitro model of human induced pluripotent stem cells (hiPSC)-derived retinal pigment epithelial (iRPE) cells and exposed them to white, blue and red lights from LED devices at doses below 22 J/cm. We show that exposure to white light at a dose of 3.6 J/cm induces an alteration of the global cellular structure, DNA damage and an activation of cellular stress pathways. The exposure to blue light triggers DNA damage and the activation of autophagy, while exposure to red light modulates the inflammatory response and inhibits autophagy.
Topics: Animals; Humans; Retinal Pigment Epithelium; Induced Pluripotent Stem Cells; Retina; Primates
PubMed: 38514646
DOI: 10.1038/s41598-024-56980-9 -
Nanoscale Apr 2024Theranostic nanoparticles hold promise for simultaneous imaging and therapy in colorectal cancer. Carcinoembryonic antigen can be used as a target for these...
Theranostic nanoparticles hold promise for simultaneous imaging and therapy in colorectal cancer. Carcinoembryonic antigen can be used as a target for these nanoparticles because it is overexpressed in most colorectal cancers. Affimer reagents are synthetic proteins capable of binding specific targets, with additional advantages over antibodies for targeting. We fabricated silica nanoparticles using a water-in-oil microemulsion technique, loaded them with the photosensitiser Foslip, and functionalised the surface with anti-CEA Affimers to facilitate fluorescence imaging and photodynamic therapy of colorectal cancer. CEA-specific fluorescence imaging and phototoxicity were quantified in colorectal cancer cell lines and a LS174T murine xenograft colorectal cancer model. Anti-CEA targeted nanoparticles exhibited CEA-specific fluorescence in the LoVo, LS174T and HCT116 cell lines when compared to control particles ( < 0.0001). No toxicity was observed in LS174T cancer mouse xenografts or other organs. Following photo-irradiation, the anti-CEA targeted particles caused significant cell death in LoVo (60%), LS174T (90%) and HCT116 (70%) compared to controls ( < 0.0001). Photodynamic therapy (PDT) at 24 h showed a 4-fold reduction in tumour volume compared to control mouse xenografts ( < 0.0001). This study demonstrates the efficacy of targeted fluorescence imaging and PDT using Foslip nanoparticles conjugated to anti-CEA Affimer nanoparticles in and colorectal cancer models.
Topics: Humans; Animals; Mice; Carcinoembryonic Antigen; Colorectal Neoplasms; Cell Line, Tumor; Nanoparticles; Mesoporphyrins
PubMed: 38506227
DOI: 10.1039/d3nr04118b -
ACS Applied Bio Materials Mar 2024Nanoparticles (NPs) are continuously being developed for many applications including imaging, biomedicine, and everyday products. It is difficult to avoid contact with...
Nanoparticles (NPs) are continuously being developed for many applications including imaging, biomedicine, and everyday products. It is difficult to avoid contact with NPs such as titanium dioxide (TiO) NPs, which are widely used in sunscreens. However, the safety of TiO NPs for skin contact and inhalation remains controversial. If NPs cannot penetrate the skin, they will be unable to circulate in the bloodstream, accumulate in the body, or cause side effects, ensuring their safety. Therefore, this study aimed to modify TiO NP surfaces to inhibit their uptake in skin cells. Inspired by protein corona studies, bovine serum albumin (BSA) was chosen to functionalize TiO NP surfaces via physical adsorption. The maximum BSA adsorption occurred at pH 5.0. The physicochemical properties (size, ζ-potential, morphology, ultraviolet (UV) absorption efficiency, and sun protection factor (SPF)) of TiO-BSA NPs were comparable to those of TiO NPs, indicating that these properties did not affect cellular uptake. In the safety evaluation, TiO NPs and TiO-BSA NPs exhibited high biocompatibility with skin cells and no phototoxicity after UVA and UVB irradiation. In the efficacy evaluation, both NPs possessed the same photoprotection abilities, reducing membrane damage and DNA breakage after UVA irradiation. Compared with TiO NPs, TiO-BSA NPs showed substantially reduced skin penetration in Franz diffusion cells (91%) and human immortalized keratinocyte (HaCaT) cells (89%). A qualitative cellular uptake study using transmission electron microscopy and confocal laser scanning microscopy confirmed that TiO NPs were more abundant than TiO-BSA NPs inside the HaCaT cells. These findings indicate that TiO surface functionalization with BSA inhibits cellular uptake in skin cells while maintaining safety and UV protection efficacy, which might be extended to other NP-based sunscreens.
Topics: Humans; Serum Albumin, Bovine; Sunscreening Agents; Adsorption; Nanoparticles; Titanium
PubMed: 38494987
DOI: 10.1021/acsabm.3c01138