Carbon Nanohorns as Photochemical and Photothermal Agents

Author(s):  
Saugata Sarkar ◽  
Amy Lutkus ◽  
James Mahaney ◽  
Harry Dorn ◽  
Tom Campbell ◽  
...  

Laser therapies based on photochemical or photothermal mechanisms can provide a minimally invasive and potentially more effective treatment alternative to conventional surgical resection procedures by delivering prescribed optical/thermal doses to a targeted tissue volume with minimal damage to intervening and surrounding tissues. However laser therapy effectiveness is limited due to nonspecific excitation/heating of target tissue which often results in healthy tissue injury. Nanostructures targeted to tumor cells and utilized in combination with laser excitation can enhance treatment effectiveness by increasing thermal deposition and generating toxic photo-chemical mediators in the form of reactive oxygen species for targeted cell destruction.

Author(s):  
Saugata Sarkar ◽  
Marissa Nichole Rylander

The goal of the project is to develop an effective treatment planning computational tool for nanotube-mediated laser therapy that maximizes tumor destruction and minimizes tumor recurrence. Laser therapies can provide a minimally invasive treatment alternative to surgical resection of tumors. However, the effectiveness of these therapies is limited due to nonspecific heating of target tissue and diffusion limited thermal deposition which often leads to healthy tissue injury and extended treatment durations. These therapies can be further compromised due to induction of molecular chaperones called heat shock protein (HSP) in tumor regions where non-lethal temperature elevation occurs causing enhanced tumor cell viability and imparting resistance to chemotherapy and radiation treatments which are generally employed in conjunction with hyperthermia.


Biology ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 18
Author(s):  
Amelia Charlton ◽  
Jessica Garzarella ◽  
Karin A. M. Jandeleit-Dahm ◽  
Jay C. Jha

Oxidative stress and inflammation are considered major drivers in the pathogenesis of diabetic complications, including renal and cardiovascular disease. A symbiotic relationship also appears to exist between oxidative stress and inflammation. Several emerging therapies target these crucial pathways, to alleviate the burden of the aforementioned diseases. Oxidative stress refers to an imbalance between reactive oxygen species (ROS) and antioxidant defenses, a pathological state which not only leads to direct cellular damage but also an inflammatory cascade that further perpetuates tissue injury. Emerging therapeutic strategies tackle these pathways in a variety of ways, from increasing antioxidant defenses (antioxidants and Nrf2 activators) to reducing ROS production (NADPH oxidase inhibitors and XO inhibitors) or inhibiting the associated inflammatory pathways (NLRP3 inflammasome inhibitors, lipoxins, GLP-1 receptor agonists, and AT-1 receptor antagonists). This review summarizes the mechanisms by which oxidative stress and inflammation contribute to and perpetuate diabetes associated renal and cardiovascular disease along with the therapeutic strategies which target these pathways to provide reno and cardiovascular protection in the setting of diabetes.


Pathobiology ◽  
2021 ◽  
pp. 1-8
Author(s):  
Naoyuki Matsumoto ◽  
Daisuke Omagari ◽  
Ryoko Ushikoshi-Nakayama ◽  
Tomoe Yamazaki ◽  
Hiroko Inoue ◽  
...  

<b><i>Introduction:</i></b> Type-2 diabetes mellitus (T2DM) is associated with several systemic vascular symptoms and xerostomia. It is considered that hyperglycemia-induced polyuria and dehydration cause decreased body-water volume, leading to decreased saliva secretion and, ultimately, xerostomia. In T2DM, increased production of reactive oxygen species (ROS) causes tissue damage to vascular endothelial cells as well as epithelial tissue, including pancreas and cornea. Hence, a similar phenomenon may occur in other tissues and glands in a hyperglycemic environment. <b><i>Methods:</i></b> Salivary gland tissue injury was examined, using T2DM model mouse (db/db). Transferase‐mediated dUTP nick‐end labeling (TUNEL) was conducted to evaluate tissue injury. The levels of malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine, Bax/Bcl-2 ratio were measured as indicator of oxidative stress. Moreover, in vitro ROS production and cell injury was evaluated by mouse salivary gland-derived normal cells under high-glucose condition culture. <b><i>Results:</i></b> In vivo and in vitro analysis showed a higher percentage of TUNEL-positive cells and higher levels of MDA and 8-hydroxy-2′-deoxyguanosine in salivary gland tissue of db/db mice. This suggests damage of saliva secretion-associated lipids and DNA by hyperglycemic-induced oxidative stress. To analyze the mechanism by which hyperglycemia promotes ROS production, mouse salivary gland-derived cells were isolated. The cell culture with high-glucose medium enhanced ROS production and promotes apoptotic and necrotic cell death. <b><i>Conclusion:</i></b> These findings suggest a novel mechanism whereby hyperglycemic-induced ROS production promotes salivary gland injury, resulting in hyposalivation.


2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Sunil Joshi ◽  
Ammon B. Peck ◽  
Saeed R. Khan

A major role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes is to catalyze the production of superoxides and other reactive oxygen species (ROS). These ROS, in turn, play a key role as messengers in cell signal transduction and cell cycling, but when they are produced in excess they can lead to oxidative stress (OS). Oxidative stress in the kidneys is now considered a major cause of renal injury and inflammation, giving rise to a variety of pathological disorders. In this review, we discuss the putative role of oxalate in producing oxidative stress via the production of reactive oxygen species by isoforms of NADPH oxidases expressed in different cellular locations of the kidneys. Most renal cells produce ROS, and recent data indicate a direct correlation between upregulated gene expressions of NADPH oxidase, ROS, and inflammation. Renal tissue expression of multiple NADPH oxidase isoforms most likely will impact the future use of different antioxidants and NADPH oxidase inhibitors to minimize OS and renal tissue injury in hyperoxaluria-induced kidney stone disease.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1345
Author(s):  
Sherif Ashraf Fahmy ◽  
Hassan Mohamed El-Said Azzazy ◽  
Jens Schaefer

Photodynamic therapy (PDT) is a promising non-invasive strategy in the fight against that which circumvents the systemic toxic effects of chemotherapeutics. It relies on photosensitizers (PSs), which are photoactivated by light irradiation and interaction with molecular oxygen. This generates highly reactive oxygen species (such as 1O2, H2O2, O2, ·OH), which kill cancer cells by necrosis or apoptosis. Despite the promising effects of PDT in cancer treatment, it still suffers from several shortcomings, such as poor biodistribution of hydrophobic PSs, low cellular uptake, and low efficacy in treating bulky or deep tumors. Hence, various nanoplatforms have been developed to increase PDT treatment effectiveness and minimize off-target adverse effects. Liposomes showed great potential in accommodating different PSs, chemotherapeutic drugs, and other therapeutically active molecules. Here, we review the state-of-the-art in encapsulating PSs alone or combined with other chemotherapeutic drugs into liposomes for effective tumor PDT.


Author(s):  
Stefan A. Sigurdsson ◽  
Zeyang Yu ◽  
Joonhee Lee ◽  
Arto Nurmikko

AbstractWireless networks of implantable electronic sensors and actuators on the microscale (sub-mm) are being explored for monitoring and modulation of physiological activity for medical diagnostics and therapeutic purposes. Beyond the requirement of integrating multiple electronic or chemical functions within small device volumes, a key challenge is the development of high-throughput methods for implantation of large numbers of microdevices into soft tissues with minimal damage. To that end, we have developed a method for high-throughput implantation of ∼100-200 μm size devices which are here simulated by proxy microparticle ensembles. While generally applicable to subdermal tissue, our main focus and experimental testbed is the implantation of microparticles into the brain. The method deploys a scalable delivery tool composed of a 2-dimensional array of polyethylene glycol tipped microneedles which confine the microparticle payloads. Upon dissolution of the bioresorbable polyethylene glycol, the supporting array structure is retrieved and the microparticles remain embedded in the tissue, distributed spatially and geometrically according to the design of the microfabricated delivery tool. We first evaluated the method in an agarose testbed in terms of spatial precision and throughput for up to 1000 passive spherical and planar microparticles acting as proxy devices. We then performed the same evaluations of particles implanted into the rat cortex under acute conditions and assessed the tissue injury produced by our method of implantation under chronic conditions.


1995 ◽  
Vol 27 (Supplement) ◽  
pp. S5 ◽  
Author(s):  
S. W. Flanagan ◽  
C. V. Gisolfi ◽  
R. D. Matthes ◽  
P. L. Moseley

Nanoscale ◽  
2015 ◽  
Vol 7 (7) ◽  
pp. 2834-2840 ◽  
Author(s):  
Minfang Zhang ◽  
Mei Yang ◽  
Cyrill Bussy ◽  
Sumio Iijima ◽  
Kostas Kostarelos ◽  
...  

Biodegradation of carbon nanohorns by MPO catalytic oxidation and by mouse and human monocyte-derived macrophages is presented. MPO catalytic oxidation and macrophages degrade approximately 60 wt% and 30 wt% of CNHs, respectively. Uptake of CNHs by macrophage cells induces the release of reactive oxygen species that results in CNH degradation.


Antioxidants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 118 ◽  
Author(s):  
Débora Levy ◽  
Cadiele Oliana Reichert ◽  
Sérgio Paulo Bydlowski

Aging is defined as the accumulation of progressive organ dysfunction. There is much evidence linking the involvement of oxidative stress in the pathogenesis of aging. With increasing age, susceptibility to the development of diseases related to lipid peroxidation and tissue injury increases, due to chronic inflammatory processes, and production of reactive oxygen species (ROS) and free radicals. The paraoxonase (PON) gene family is composed of three members (PON1, PON2, PON3) that share considerable structural homology and are located adjacently on chromosome 7 in humans. The most studied member product is PON1, a protein associated with high-density lipoprotein with paraoxonase/esterase activity. Nevertheless, all the three proteins prevent oxidative stress. The major aim of this review is to highlight the importance of the role of PON enzymes in the aging process, and in the development of the main diseases present in the elderly: cardiovascular disease, diabetes mellitus, neurodegenerative diseases, and cancer.


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