Potentials of medicinal nanostructured diamond particles and coatings

2021 ◽  
Author(s):  
Moataz Dowaidar
Keyword(s):  
Chemical Stability ◽  
Clinical Medicine ◽  
The Body ◽  
Specific Cell ◽  
Diamond Surfaces ◽  
Diamond Particles ◽  
In Vivo Testing ◽  
The Impact

Particles and coatings can be manufactured utilizing low-cost, scalable processes. In both in vitro and in vivo experiments, unmodified diamond materials displayed good cell biocompatibility. Most current nanostructured diamond research focuses on diamond surfaces for specific cell and tissue interactions. Although the chemical stability of functionalized diamond surfaces has been explored for relatively short periods of time, the functionalized surface's chemical stability while its use in the body deserves additional exploration. In addition, the impact of chemistry (e.g., pH), enzymes, and microorganisms on the functionalized diamond surface's chemical stability must be considered. Moreover, the goals of studies evaluating the biological functionality of nanostructured diamond materials must be better aligned with regulatory requirements (e.g., ASTM International and the International Organization for Standardization) and in vitro and in vivo testing requirements of government agencies (e.g. the U.S. Food & Drug Administration). Because national regulatory authorities generally review medical devices rather than biomaterials, the parameters of in vitro and in vivo research should be closer to the implantation site's biological, chemical and mechanical features. Research on the breakdown of nanostructured diamond devices and the presence of degradation products in surrounding and remote tissues is needed. Thinking about how the sterilizing technique impacts the surface properties and biocompatibility of nanostructured diamond materials is equally significant. As the stability and fate of functionalized diamond particles and surfaces is better known via more in-vitro and in-vivo testing, nanostructured diamond materials are likely to play a greater role in clinical medicine.

scholarly journals Hemoglobin stimulates vigorous growth of Streptococcus pneumoniae and shapes the pathogen's global transcriptome

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fahmina Akhter ◽  
Edroyal Womack ◽  
Jorge E. Vidal ◽  
Yoann Le Breton ◽  
Kevin S. McIver ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Positive Influence ◽  
The Body ◽  
Host Proteins ◽  
Vigorous Growth ◽  
Cultivation In Vitro ◽  
The Impact ◽  
Heme Binding Protein

Abstract Streptococcus pneumoniae (Spn) must acquire iron from the host to establish infection. We examined the impact of hemoglobin, the largest iron reservoir in the body, on pneumococcal physiology. Supplementation with hemoglobin allowed Spn to resume growth in an iron-deplete medium. Pneumococcal growth with hemoglobin was unusually robust, exhibiting a prolonged logarithmic growth, higher biomass, and extended viability in both iron-deplete and standard medium. We observed the hemoglobin-dependent response in multiple serotypes, but not with other host proteins, free iron, or heme. Remarkably, hemoglobin induced a sizable transcriptome remodeling, effecting virulence and metabolism in particular genes facilitating host glycoconjugates use. Accordingly, Spn was more adapted to grow on the human α − 1 acid glycoprotein as a sugar source with hemoglobin. A mutant in the hemoglobin/heme-binding protein Spbhp-37 was impaired for growth on heme and hemoglobin iron. The mutant exhibited reduced growth and iron content when grown in THYB and hemoglobin. In summary, the data show that hemoglobin is highly beneficial for Spn cultivation in vitro and suggest that hemoglobin might drive the pathogen adaptation in vivo. The hemoglobin receptor, Spbhp-37, plays a role in mediating the positive influence of hemoglobin. These novel findings provide intriguing insights into pneumococcal interactions with its obligate human host.

Astatine-211 labelled a small molecule peptide: specific cell killing in vitro and targeted therapy in a nude-mouse model

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Weihao Liu ◽  
Yu Tang ◽  
Huan Ma ◽  
Feize Li ◽  
Yingjiang Hu ◽  
...  
Keyword(s):  
Small Molecule ◽  
Cell Killing ◽  
The Body ◽  
Control Group ◽  
Specific Cell ◽  
Step Method ◽  
Nude Mouse Model ◽  
Tissue Samples

AbstractExtensive interest in the development of α-emitting radionuclides astatine-211 (211At) stems from the potential superiority for the treatment of smaller tumors, disseminated disease, and metastatic disease. VP2, a small molecule fusion peptide, can specifically bind to the VPAC1 receptor which is over-expressed in malignant epithelial tumors. In our recent study, we performed the preparation of 211At labelled VP2 through a one-step method. In this work, we explored the targeted radionuclide therapy with [211At]At-SPC-VP2 in vitro and in vivo. The cytotoxicity and specific cell killing of [211At]At-SPC-VP2 were evaluated using the CCK-8 assay. Compared with the [211At]NaAt, the VPAC1-targeted radionuclide compound [211At]At-SPC-VP2 showed more effective cytotoxicity in vitro. Targeted radioactive therapy trial was carried out in non-small-cell lung cancer (NSCLC) xenograft mice. For the therapy experiment, 4 groups of mice were injected via the tail vein with 370 kBq, 550 kBq, 740 kBq, 3 × ∼246 kBq of [211At]At-SPC-VP2, of which the second and third injections were given 4 and 8 days after the first injection, respectively. As controls, animals were treated with saline or 550 kBq [211At]NaAt. The body weight and tumor size of mice were monitored before the administration and every 2 days thereafter. Cytotoxic radiation of partial tissue samples such as kidneys, liver and stomach of mice were assessed by immunohistochemical examination. The tumor growth was inhibited and significantly improved survival was achieved in mice treated with [211At]At-SPC-VP2, two-fold prolongation of survival compared with the control group, which received normal saline or 550 kBq [211At]NaAt. No renal or hepatic toxicity was observed in the mice receiving [211At]At-SPC-VP2, but gastric pathological sections showed 211At uptake in stomach resulting in later toxicity, highlighting the importance of further enhancing the stability of labelled compounds.

scholarly journals Development and Physiological Functions of the Lymphatic System - Insights from Genetic Studies of Lymphedema

2021 ◽  
Author(s):  
Silvia Martin-Almedina ◽  
Peter Mortimer ◽  
Pia Ostergaard
Keyword(s):  
Lymphatic System ◽  
Imaging Techniques ◽  
The Body ◽  
Genetic Studies ◽  
Disease Mechanisms ◽  
Primary Lymphedema ◽  
And Function ◽  
The Impact

Primary lymphedema is a long-term (chronic) condition characterized by tissue lymph retention and swelling that can affect any part of the body, although it usually develops in the arms or legs. Due to the relevant contribution of the lymphatic system to human physiology, while this review mainly focusses on the clinical and physiological aspects related to the regulation of fluid homeostasis and edema, clinicians need to know that the impact of lymphatic dysfunction with a genetic origin can be wide ranging. Lymphatic gene dysfunction can affect immune function so leading to infection; it can influence cancer development and spread; and it can determine fat transport so impacting on nutrition and obesity. Genetic studies and the development of imaging techniques for the assessment of lymphatic function have enabled the recognition of primary lymphedema as a heterogenic condition in terms of genetic causes and disease mechanisms. In this review, the known biological function of several genes crucial to the development and function of the lymphatic system are used as a basis for understanding normal lymphatic biology. The disease conditions originating from mutations in these genes are discussed together with a detailed clinical description of the phenotype and the up-to-date knowledge in terms of disease mechanisms acquired from in vitro and in vivo research models.

scholarly journals Biogenic Ferrihydrite Nanoparticles: Synthesis, Properties In Vitro and In Vivo Testing and the Concentration Effect

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 323
Author(s):  
Sergey V. Stolyar ◽  
Oksana A. Kolenchukova ◽  
Anna V. Boldyreva ◽  
Nadezda S. Kudryasheva ◽  
Yulia V. Gerasimova ◽  
...  
Keyword(s):  
Klebsiella Oxytoca ◽  
The Body ◽  
Blocking Temperature ◽  
Laboratory Animals ◽  
High Dispersion ◽  
Intracellular Regeneration ◽  
Minimum Concentration ◽  
In Vivo Testing

Biogenic ferrihydrite nanoparticles were synthesized as a result of the cultivation of Klebsiella oxytoca microorganisms. The distribution of nanoparticles in the body of laboratory animals and the physical properties of the nanoparticles were studied. The synthesized ferrihydrite nanoparticles are superparamagnetic at room temperature, and the characteristic blocking temperature is 23–25 K. The uncompensated moment of ferrihydrite particles was determined to be approximately 200 Bohr magnetons. In vitro testing of different concentrations of ferrihydrite nanoparticles for the functional activity of neutrophilic granulocytes by the chemiluminescence method showed an increase in the release of primary oxygen radicals by blood phagocytes when exposed to a minimum concentration and a decrease in secondary radicals when exposed to a maximum concentration. In vivo testing of ferrihydrite nanoparticles on Wister rats showed that a suspension of ferrihydrite nanoparticles has chronic toxicity, since it causes morphological changes in organs, mainly in the spleen, which are characterized by the accumulation of hemosiderin nanoparticles (stained blue according to Perls). Ferrihydrite can also directly or indirectly stimulate the proliferation and intracellular regeneration of hepatocytes. The partial detection of Perls-positive cells in the liver and kidneys can be explained by the rapid elimination from organs and the high dispersion of the nanomaterial. Thus, it is necessary to carry out studies of these processes at the systemic level, since the introduction of nanoparticles into the body is characterized by adaptive-proliferative processes, accompanied by the development of cell dystrophy and tension of the phagocytic system.

GIT Physicochemical Modeling - A Critical Review

2006 ◽  
Vol 2 (4) ◽  
Author(s):  
'Michelle' Ji Yeon Yoo ◽  
Xiao Dong Chen
Keyword(s):  
The Body ◽  
In Vivo Model ◽  
Chemical Models ◽  
In Vivo Testing ◽  
Computer Controlled ◽  
Vitro Model ◽  
Key Aspects ◽  
Physiological And Biochemical

Many attempts to model the human gastrointestinal tract (GIT) were made since the beginning of the last decade. The main purpose was either to simulate an in vivo testing of drugs on animals or to investigate the viability of the probiotic intake. Two well-known physio-chemical models regarding the viability of the probiotics have been produced. In 1993, Molly et al. developed a simulator of the human intestinal microbial ecosystem (SHIME). Six reactors simulating the conditions of human stomach, duodenum/jejunum, ileum, caecum/ascending colon, transverse colon and descending colon were artificially developed. In 1995, Minekus et al. created a TNO gastro-intestinal model (TIM) with four computer-controlled chambers simulating the conditions of stomach, duodenum, jejunum and ileum. The simulated parameters included the body temperature, pH, salivary, gastric and intestinal mixing with peristaltic movements, secretions and absorption of water and small molecules. Despite the use of pharmacological, physiological and biochemical knowledge of the human and animal GIT and associated secretions, conflicting results such as the extremely low viability of probiotics were obtained. The failure of the above two models indicates the necessity of devising a suitable in vitro model that would be capable of simulating the digestion process as an exact replica of the actual in vivo model. In this paper, the key aspects of the above have been summarized and discussed.

scholarly journals Immune response and pathogen invasion at the choroid plexus in the onset of cerebral toxoplasmosis

2022 ◽  
Vol 19 (1) ◽  
Author(s):  
Caio Andreeta Figueiredo ◽  
Johannes Steffen ◽  
Lorena Morton ◽  
Sushmitha Arumugam ◽  
Oliver Liesenfeld ◽  
...  
Keyword(s):  
Immune Response ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Choroid Plexus ◽  
The Body ◽  
Potential Contribution ◽  
Pathogen Invasion ◽  
The Impact

Abstract Background Toxoplasma gondii (T. gondii) is a highly successful parasite being able to cross all biological barriers of the body, finally reaching the central nervous system (CNS). Previous studies have highlighted the critical involvement of the blood–brain barrier (BBB) during T. gondii invasion and development of subsequent neuroinflammation. Still, the potential contribution of the choroid plexus (CP), the main structure forming the blood–cerebrospinal fluid (CSF) barrier (BCSFB) have not been addressed. Methods To investigate T. gondii invasion at the onset of neuroinflammation, the CP and brain microvessels (BMV) were isolated and analyzed for parasite burden. Additionally, immuno-stained brain sections and three-dimensional whole mount preparations were evaluated for parasite localization and morphological alterations. Activation of choroidal and brain endothelial cells were characterized by flow cytometry. To evaluate the impact of early immune responses on CP and BMV, expression levels of inflammatory mediators, tight junctions (TJ) and matrix metalloproteinases (MMPs) were quantified. Additionally, FITC-dextran was applied to determine infection-related changes in BCSFB permeability. Finally, the response of primary CP epithelial cells to T. gondii parasites was tested in vitro. Results Here we revealed that endothelial cells in the CP are initially infected by T. gondii, and become activated prior to BBB endothelial cells indicated by MHCII upregulation. Additionally, CP elicited early local immune response with upregulation of IFN-γ, TNF, IL-6, host-defence factors as well as swift expression of CXCL9 chemokine, when compared to the BMV. Consequently, we uncovered distinct TJ disturbances of claudins, associated with upregulation of MMP-8 and MMP-13 expression in infected CP in vivo, which was confirmed by in vitro infection of primary CP epithelial cells. Notably, we detected early barrier damage and functional loss by increased BCSFB permeability to FITC-dextran in vivo, which was extended over the infection course. Conclusions Altogether, our data reveal a close interaction between T. gondii infection at the CP and the impairment of the BCSFB function indicating that infection-related neuroinflammation is initiated in the CP.

scholarly journals Understanding the impact of more realistic low-dose, prolonged engineered nanomaterial exposure on genotoxicity using 3D models of the human liver

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Samantha V. Llewellyn ◽  
Gillian E. Conway ◽  
Ilaria Zanoni ◽  
Amalie Kofoed Jørgensen ◽  
Ume-Kulsoom Shah ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
3D Models ◽  
Single Bolus ◽  
Organ Systems ◽  
In Vivo Testing ◽  
Human Health Effects ◽  
The Impact ◽  
Dose Dependent

Abstract Background With the continued integration of engineered nanomaterials (ENMs) into everyday applications, it is important to understand their potential for inducing adverse human health effects. However, standard in vitro hazard characterisation approaches suffer limitations for evaluating ENM and so it is imperative to determine these potential hazards under more physiologically relevant and realistic exposure scenarios in target organ systems, to minimise the necessity for in vivo testing. The aim of this study was to determine if acute (24 h) and prolonged (120 h) exposures to five ENMs (TiO2, ZnO, Ag, BaSO4 and CeO2) would have a significantly different toxicological outcome (cytotoxicity, (pro-)inflammatory and genotoxic response) upon 3D human HepG2 liver spheroids. In addition, this study evaluated whether a more realistic, prolonged fractionated and repeated ENM dosing regime induces a significantly different toxicity outcome in liver spheroids as compared to a single, bolus prolonged exposure. Results Whilst it was found that the five ENMs did not impede liver functionality (e.g. albumin and urea production), induce cytotoxicity or an IL-8 (pro-)inflammatory response, all were found to cause significant genotoxicity following acute exposure. Most statistically significant genotoxic responses were not dose-dependent, with the exception of TiO2. Interestingly, the DNA damage effects observed following acute exposures, were not mirrored in the prolonged exposures, where only 0.2–5.0 µg/mL of ZnO ENMs were found to elicit significant (p ≤ 0.05) genotoxicity. When fractionated, repeated exposure regimes were performed with the test ENMs, no significant (p ≥ 0.05) difference was observed when compared to the single, bolus exposure regime. There was < 5.0% cytotoxicity observed across all exposures, and the mean difference in IL-8 cytokine release and genotoxicity between exposure regimes was 3.425 pg/mL and 0.181%, respectively. Conclusion In conclusion, whilst there was no difference between a single, bolus or fractionated, repeated ENM prolonged exposure regimes upon the toxicological output of 3D HepG2 liver spheroids, there was a difference between acute and prolonged exposures. This study highlights the importance of evaluating more realistic ENM exposures, thereby providing a future in vitro approach to better support ENM hazard assessment in a routine and easily accessible manner.

scholarly journals Immune Response and Pathogen Invasion at the Choroid Plexus in the Onset of Cerebral Toxoplasmosis

2021 ◽  
Author(s):  
Caio Andreeta Figueiredo ◽  
JOhannes Steffen ◽  
Lorena Morton ◽  
Sushmita Arumugam ◽  
OLiver Liesenfeld ◽  
...  
Keyword(s):  
Immune Response ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Choroid Plexus ◽  
The Body ◽  
Potential Contribution ◽  
Pathogen Invasion ◽  
The Impact

Abstract Background: Toxoplasma gondii ( T. gondii ) is a highly successful parasite being able to cross all biological barriers of the body, finally reaching the central nervous system (CNS). Previous studies have highlighted the critical involvement of the blood-brain barrier (BBB) during T. gondii invasion and development of subsequent neuroinflammation. Still, the potential contribution of the choroid plexus (CP), a main structure forming the blood-cerebrospinal fluid (CSF)-barrier (BCSFB) have not been addressed. Methods: To investigate T. gondii invasion and the onset of neuroinflammation, the CP and brain microvessels (BMV) were isolated and analysed for parasite burden. Additionally, immuno-stained brain sections and three dimensional whole mount preparations were evaluated for parasite localization and morphological alterations. Activation of choroidal and brain endothelial cells were characterized by flow cytometry. To evaluate the impact of early immune responses on CP and BMV, expression levels of inflammatory mediators, tight junctions (TJ) and matrix metalloproteinases (MMPs) were quantified. Additionally, FITC-dextran was applied to determine infection-related changes in BCSFB permeability. Finally, the response of primary CP epithelial cells to T. gondii parasites was tested in vitro . Results: Here we revealed that endothelial cells in the CP are initially infected by T. gondii, and become activated prior to BBB endothelial cells indicated by MHCII upregulation. Additionally, CP elicited early local immune response with upregulation of IFN-γ, TNF, IL-6, host-defence factors as well as swift expression of CXCL9 chemokine, when compared to the BMV. Consequently, we uncovered distinct TJ disturbances of claudins, associated with upregulation of MMP-8 and MMP-13 expression in infected CP in vivo , which was confirmed by in vitro infection of primary CP epithelial cells. Notably, we detected early barrier damage and functional loss by increased BCSFB permeability to FITC-dextran in vivo , which was extended over the infection course. Conclusions: Altogether, our data reveal a close interaction between T. gondii infection at the CP and the impairment of the BCSFB function indicating that infection-related neuroinflammation is initiated in the CP.

scholarly journals Edward F. Adolph Distinguished Lecture: Skin-deep insights into vascular aging

2017 ◽  
Vol 123 (5) ◽  
pp. 1024-1038 ◽  
Author(s):  
W. Larry Kenney
Keyword(s):  
Vascular Function ◽  
Microvascular Dysfunction ◽  
The Body ◽  
Doppler Flowmetry ◽  
Microvascular Changes ◽  
Age Related ◽  
Aged Skin ◽  
The Impact

The skin is an accessible model circulation for studying vascular function and dysfunction across the lifespan. Age-related changes, as well as those associated with disease progression, often appear first in the cutaneous circulation. Furthermore, impaired vascular signaling and attendant endothelial dysfunction, the earliest indicators of cardiovascular pathogenesis, occur in a similar fashion across multiple tissue beds throughout the body, including the skin. Because microvascular dysfunction is a better predictor of long-term outcomes and adverse cardiovascular events than is large vessel disease, an understanding of age-associated changes in the control of the human cutaneous microcirculation is important. This review focuses on 1) the merits of using skin-specific methods and techniques to study vascular function, 2) microvascular changes in aged skin (in particular, the role of the endothelial-derived dilator nitric oxide), and 3) the impact of aging on heat-induced changes in skin vasodilation. While skin blood flow is controlled by multiple, often redundant, mechanisms, our laboratory has used a variety of distinct thermal provocations of this model circulation to isolate specific age-associated changes in vascular function. Skin-specific approaches and techniques, such as intradermal microdialysis coupled with laser-Doppler flowmetry (in vivo) and biochemical analyses of skin biopsy samples (in vitro), have allowed for the targeted pharmacodissection of the mechanistic pathways controlling skin vasoreactivity and study of the impact of aging and disease states. Aged skin has an attenuated ability to vasodilate in response to warm stimuli and to vasoconstrict in response to cold stimuli.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

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