Ultrasmall polymer-coated cerium oxide nanoparticles as a traumatic brain injury therapy

Excipients for Cerium Dioxide Nanoparticle Stabilization in the Perspective of Biomedical Applications

Rare earth metal nanoparticles, some of which are already widely used in medicine, are of growing interest in the modern scientific community. One of the promising rare earth metals for biomedical applications is cerium, specifically its oxide form, which is characterized by a higher level of stability and safety. According to a number of studies, cerium dioxide has a wide range of biological effects (regenerative, antimicrobial, antioxidant, antitumor), which justifies the interest of its potential application in medicine. However, these effects and their intensity vary significantly across a number of studies. Since cerium dioxide was used in these studies, it can be assumed that not only is the chemical formula important, but also the physicochemical parameters of the nanoparticles obtained, and consequently the methods of their synthesis and modification with the use of excipients. In this review, we considered the possibilities of using a number of excipients (polyacrylate, polyvinylpyrrolidone, dextran, hyaluronic acid, chitosan, polycarboxylic acids, lecithin, phosphatidylcholine) in the context of preserving the biological effects of cerium dioxide and its physicochemical properties, as well as the degree of study of these combinations from the point of view of the prospect of creating drugs based on it for biomedical applications.

Potential Applications of Rare Earth Metal Nanoparticles in Biomedicine

In recent years, the world scientific community has shown increasing interest in rare earth metals in general and their nanoparticles in particular. Medicine and pharmaceuticals are no exception in this matter. In this review, we have considered the main opportunities and potential applications of rare earth metal (gadolinium, europium, ytterbium, holmium, lutetium, dysprosium, erbium, terbium, thulium, scandium, yttrium, lanthanum, europium, neodymium, promethium, samarium, praseodymium, cerium) nanoparticles in biomedicine, with data ranging from single reports of effects found in vitro to numerous independent in vivo studies, as well as a number of challenges to their potential for wider application. The main areas of application of rare earth metals, including in the future, are diagnosis and treatment of malignant neoplasms, therapy of infections, as well as the use of antioxidant and regenerative properties of a number of nanoparticles. These applications are determined both by the properties of rare earth metal nanoparticles themselves and the need to search for new approaches to solve a number of urgent biomedical and public health problems. Oxide forms of lanthanides are most often used in biomedicine due to their greatest biocompatibility and nanoscale size, providing penetration through biological membranes. However, the existing contradictory or insufficient data on acute and chronic toxicity of lanthanides still make their widespread use difficult. There are various modification methods (addition of excipients, creation of nanocomposites, and changing the morphology of particles) that can reduce these effects. At the same time, despite the use of some representatives of lanthanides in clinical practice, further studies to establish the full range of pharmacological and toxic effects, as well as the search for approaches to modify nanoparticles remain relevant.

Nanoceria Aggregate Formulation Promotes Buffer Stability, Cell Clustering, and Reduction of Adherent Biofilm in Streptococcus mutans

Streptococcus mutans is one of the key etiological factors in tooth-borne biofilm development that leads to dental caries in the presence of fermentable sugars. We previously reported on the ability of acid-stabilized nanoceria (CeO2-NP) produced by the hydrolysis of ceric salts to limit biofilm adherence of S. mutans via non-bactericidal mechanism(s). Herein, we report a chondroitin sulfate A (CSA) formulation (CeO2-NP-CSA) comprising nanoceria aggregates that promotes resistance to bulk precipitation under a range of conditions with retention of the biofilm-inhibiting activity, allowing for a more thorough mechanistic study of its bioactivity. The principal mechanism of reduced in vitro biofilm adherence of S. mutans by CeO2-NP-CSA is the production of nonadherent cell clusters. Additionally, dose-dependent in vitro human cell toxicity studies demonstrated no additional toxicity beyond that of equimolar doses of sodium fluoride, currently utilized in many oral health products. This study represents a unique approach and use of a nanoceria aggregate formulation with implications for promoting oral health and dental caries prevention as an adjunctive treatment.

Neuroprotective Effects of Milrinone on Acute Traumatic Brain Injury

BACKGROUND

Traumatic brain injury is still an important health problem worldwide. Traumatic brain injury not only causes direct mechanical damage to the brain but also induces biochemical changes that lead to secondary nerve cell loss. In this study, we investigated the neuroprotective effect of milrinone after traumatic brain injury (TBI) in a rat model.

METHODS

Forty male Wistar albino rats, were used. Rats were divided into 4 groups: 1) sham, 2) TBI, 3) TBI + Ringers, and 4) TBI + Milrinone. In group 1 (sham), only craniotomy was performed. In group 2 (TBI), TBI was performed after craniotomy. In group 3 (TBI + Ringer), TBI was performed after craniotomy and intraperitoneal Ringers solution was given immediately afterward. Group 4 (TBI + Milrinone), TBI was performed after craniotomy, and milrinone was given 1.0 mg/kg milrinone intraperitoneally directly (0.5 mg/kg milrinone intraperitoneally again 24 hours, 48 hours, and 72 hours after trauma). Tests were performed for neurological and neurobehavioral functions. Immunohistochemistry and histopathology studies were performed.

RESULTS

In group 4 compared with group 2 and group 3 groups, tests for neurological functions and neurobehavioral functions were significantly better. In the milrinone treatment used in group 4, plasma and brain tissue tumor necrosis factor, 8-OH 2-deoxyguanosine , and interleukin 6 levels were significantly decreased, and increased plasma and tissue IL-10 levels were detected. Histopathological spinal cord injury and apoptotic index increased in groups 2 and 3, while significantly decreasing in group 4.

CONCLUSIONS

This study shows for the first time that the anti-inflammatory, antioxidant and antiapoptotic properties of milrinone may be neuroprotective after TBI.

Role of Cerium Oxide Nanoparticles and Doxorubicin in Improving Cancer Management: A Mini Review

Cancer is one of the significant issues with public health and the second leading cause of death worldwide. The three most lethal cancers in the general population are stomach, lung, and liver cancers, in which lung and breast cancers cause the majority of cancer-associated deaths among men and women, respectively. CeO2 nanoparticles have a cytoprotectant effect in normal cells and a cytotoxic effect in cancer cells that enables them to induce the reactive oxygen species (ROS) production within cancer cells, which in turn develops reactive nitrogen species (RNS) that interfere with intracellular activities, and this property makes them an excellent anticancer agent. Because of its biofilm suppression, free radical scavenging ability, redox activity, and other unique properties, attention has been bestowed on cerium oxide nanoparticles as a potential alternative to solve many biomedical issues in the future. This review mainly focuses on the combinatorial effect of cerium dioxide nanoparticles and Doxorubicin in cancer management.