Hydrogels for biomedical applications.

Graphene, graphene oxide, and reduced graphene oxide have been widely considered as promising candidates for industrial and biomedical applications due to their exceptionally high mechanical stiffness and strength, excellent electrical conductivity, high optical transparency, and good biocompatibility. In this article, we reviewed several techniques that are available for the synthesis of graphene-based nanomaterials, and discussed the biocompatibility and toxicity of such nanomaterials upon exposure to mammalian cells under in vitro and in vivo conditions. Various synthesis strategies have been developed for their fabrication, generating graphene nanomaterials with different chemical and physical properties. As such, their interactions with cells and organs are altered accordingly. Conflicting results relating biocompatibility and cytotoxicity induced by graphene nanomaterials have been reported in the literature. In particular, graphene nanomaterials that are used for in vitro cell culture and in vivo animal models may contain toxic chemical residuals, thereby interfering graphene-cell interactions and complicating interpretation of experimental results. Synthesized techniques, such as liquid phase exfoliation and wet chemical oxidation, often required toxic organic solvents, surfactants, strong acids, and oxidants for exfoliating graphite flakes. Those organic molecules and inorganic impurities that are retained in final graphene products can interact with biological cells and tissues, inducing toxicity or causing cell death eventually. The residual contaminants can cause a higher risk of graphene-induced toxicity in biological cells. This adverse effect may be partly responsible for the discrepancies between various studies in the literature.

https://www.mdpi.com/1422-0067/19/11/3564/pdf

Graphene Nanomaterials: Synthesis, Biocompatibility, and Cytotoxicity.

Antimicrobial/Biocompatible Hydrogels Dual-Reinforced by Cellulose as Ultrastretchable and Rapid Self-Healing Wound Dressing

Nanomaterials have been widely used in many fields in the last decades, including electronics, biomedicine, cosmetics, food processing, buildings, and aeronautics. The application of these nanomaterials in the medical field could improve diagnosis, treatment, and prevention techniques. Graphene oxide (GO), an oxidized derivative of graphene, is currently used in biotechnology and medicine for cancer treatment, drug delivery, and cellular imaging. Also, GO is characterized by various physicochemical properties, including nanoscale size, high surface area, and electrical charge. However, the toxic effect of GO on living cells and organs is a limiting factor that limits its use in the medical field. Recently, numerous studies have evaluated the biocompatibility and toxicity of GO in vivo and in vitro. In general, the severity of this nanomaterial's toxic effects varies according to the administration route, the dose to be administered, the method of GO synthesis, and its physicochemical properties. This review brings together studies on the method of synthesis and structure of GO, characterization techniques, and physicochemical properties. Also, we rely on the toxicity of GO in cellular models and biological systems. Moreover, we mention the general mechanism of its toxicity.

/pdf/synthesis-and-toxicity-of-graphene-oxide-nanoparticles-a-3wx2kbcqn9.pdf

Synthesis and Toxicity of Graphene Oxide Nanoparticles: A Literature Review of In Vitro and In Vivo Studies

Double-network hydrogel adsorbents for environmental applications

Background Graphene is considered as a wonder material; it is the strongest material on the planet, super-elastic, and conductive. Its application in biomedicine is huge, with a multibillion-dollar industry, and will revolutionize the diagnostic and treatment of diseases. However, its safety and potential toxicity is the main challenge. Methods This study assessed the potential toxicity of graphene oxide nanoplatelets (GONs) in an in vivo animal model using systemic, hematological, biochemical, and histopathological examinations. Normal saline (control group) or GONs (3-6 layers, lateral dimension=5-10 μm, and thickness=0.8-2 nm) at dose rate of 50, 150, or 500 mg/kg were intraperitoneally injected into adult male Wistar rats (n=5) every 48 hours during 1 week to receive each animal a total of four doses. The animals were allowed 2 weeks to recover after the last dosing. Then, animals were killed and the blood was collected for hematological and biochemical analysis. The organs including the liver, kidney, spleen, lung, intestine, brain, and heart were harvested for histopathological evaluations. Results The results showed GONs prevented body weight gain in animals after 21 days, treated at 500 mg/kg, but not in the animals treated at 150 or 50 mg/kg GONs. The biochemical analysis showed a significant increase in total bilirubin, with a significant decrease in triglycerides and high-density lipoprotein in animals treated at 500 mg/kg. Nonetheless, other hematological and biochemical parameters remained statistically insignificant in all GONs treated animals. The most common histopathological findings in the visceral organs were granulomatous reaction with giant cell formation and accumulation of GONs in capsular regions. Also, small foci of neuronal degeneration and necrosis were the most outstanding findings in the brain, including the cerebellum. Conclusion In conclusion, this study shows that GONs without functionalization are toxic. The future study is a comparison of the functionalized with non-functionalized GONs.

/pdf/in-vivo-toxicological-evaluation-of-graphene-oxide-1h0gullyx5.pdf

In vivo toxicological evaluation of graphene oxide nanoplatelets for clinical application.

Both Tough and Soft Double Network Hydrogel Nanocomposite Based on O-Carboxymethyl Chitosan/Poly(vinyl alcohol) and Graphene Oxide: A Promising Alternative for Tissue Engineering

In tropical and subtropical countries, envenomation by scorpions (so -called scorpionism) represents a serious public health probl em.In the present study ,the toxic effects of mice LD 50 injections of Mesobuthus eupeus(Me) venom on the kidney and liver of anesthetized rabbits were investigated. Six rabbits were selected and ALT,AST,BUN and creatinine were measured at 0,1 and3 hours after envenomation and histopathological studies were carried out postmortem. All the animals showed signs and symptoms of envenomation within30-40 minutes and died3 to3.5 hours after venom injection .Histopathological examinations revealed glumerol ar congestion, dilated vessels of interstitium and focal interstitial congestion in the kidney and focal hemorrhage, central vein co ngestion, congested vessels in portal areas and dilated sinusoids in the liver at 3 to3.5 hrs following venom injection .In addition,biochemical analyses indicated significant rise in the levels of ALT and creatinine following Mesobuthuseupeus envenomation in animals at3 hrs.However no significant changes were observed at 1 hr.In conclusion,scorpion(Mesobuthus

http://archrazi.areeo.ac.ir/article_103877_1a5db956c6b6e91b7514d4c78afa8ff4.pdf

Biochemical and histopathological study of Mesobuthus eupeus scorpion venom in the experimental rabbits.

Amelioration of cardio-respiratory perturbations following Mesobuthus eupeus envenomation in anesthetized rabbits with commercial polyvalent F(ab')2 antivenom.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adv.22144

Ehsan Zayerzadeh

Papers

In vivo toxicological evaluation of graphene oxide nanoplatelets for clinical application.

Both Tough and Soft Double Network Hydrogel Nanocomposite Based on O-Carboxymethyl Chitosan/Poly(vinyl alcohol) and Graphene Oxide: A Promising Alternative for Tissue Engineering

Biochemical and histopathological study of Mesobuthus eupeus scorpion venom in the experimental rabbits.

Amelioration of cardio-respiratory perturbations following Mesobuthus eupeus envenomation in anesthetized rabbits with commercial polyvalent F(ab')2 antivenom.

Synthesis and characterization of new honey incorporated double-network hydrogels based on poly(vinyl alcohol) and acylated chitosan