The Role of Chitosan and Graphene Oxide in Bioactive and Antibacterial Properties of Acrylic Bone Cements

Acrylic bone cements (ABC) are widely used in orthopedics for joint fixation, antibiotic release, and bone defect filling, among others. However, most commercially available ABCs exhibit a lack of bioactivity and are susceptible to infection after implantation. These disadvantages generate long-term loosening of the prosthesis, high morbidity, and prolonged and expensive treatments. Due to the great importance of acrylic bone cements in orthopedics, the scientific community has advanced several efforts to develop bioactive ABCs with antibacterial activity through several strategies, including the use of biodegradable materials such as chitosan (CS) and nanostructures such as graphene oxide (GO), with promising results. This paper reviews several studies reporting advantages in bioactivity and antibacterial properties after incorporating CS and GO in bone cements. Detailed information on the possible mechanisms by which these fillers confer bioactive and antibacterial properties to cements, resulting in formulations with great potential for use in orthopedics, are also a focus in the manuscript. To the best of our knowledge, this is the first systematic review that presents the improvement in biological properties with CS and GO addition in cements that we believe will contribute to the biomedical field.

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Polymethyl Methacrylate-Based Bone Cements Containing Carbon Nanotubes and Graphene Oxide: An Overview of Physical, Mechanical, and Biological Properties

Polymers ◽

10.3390/polym12071469 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1469 ◽

Cited By ~ 6

Author(s):

Sanaz Soleymani Eil Bakhtiari ◽

Hamid Reza Bakhsheshi-Rad ◽

Saeed Karbasi ◽

Mohamadreza Tavakoli ◽

Mahmood Razzaghi ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Graphene Oxide ◽

Polymethyl Methacrylate ◽

Biological Properties ◽

Bone Diseases ◽

Bone Cements ◽

Bone Fixation ◽

Primary Bone ◽

Carbon Based

Every year, millions of people in the world get bone diseases and need orthopedic surgery as one of the most important treatments. Owing to their superior properties, such as acceptable biocompatibility and providing great primary bone fixation with the implant, polymethyl methacrylate (PMMA)-based bone cements (BCs) are among the essential materials as fixation implants in different orthopedic and trauma surgeries. On the other hand, these BCs have some disadvantages, including Lack of bone formation and bioactivity, and low mechanical properties, which can lead to bone cement (BC) failure. Hence, plenty of studies have been concentrating on eliminating BC failures by using different kinds of ceramics and polymers for reinforcement and also by producing composite materials. This review article aims to evaluate mechanical properties, self-setting characteristics, biocompatibility, and bioactivity of the PMMA-based BCs composites containing carbon nanotubes (CNTs), graphene oxide (GO), and carbon-based compounds. In the present study, we compared the effects of CNTs and GO as reinforcement agents in the PMMA-based BCs. Upcoming study on the PMMA-based BCs should concentrate on trialing combinations of these carbon-based reinforcing agents as this might improve beneficial characteristics.

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Cancer Nano-Immunotherapy from the Injection to the Target: The Role of Protein Corona

International Journal of Molecular Sciences ◽

10.3390/ijms21020519 ◽

2020 ◽

Vol 21 (2) ◽

pp. 519

Author(s):

Idoia Mikelez-Alonso ◽

Antonio Aires ◽

Aitziber L. Cortajarena

Keyword(s):

Protein Corona ◽

Biological Properties ◽

Immune Reactivity ◽

Target Tissue ◽

Physiological Conditions ◽

Different Types ◽

Cancer Remission ◽

New Strategies

Immunotherapy has become a promising cancer therapy, improving the prognosis of patients with many different types of cancer and offering the possibility for long-term cancer remission. Nevertheless, some patients do not respond to these treatments and immunotherapy has shown some limitations, such as immune system resistance or limited bioavailability of the drug. Therefore, new strategies that include the use of nanoparticles (NPs) are emerging to enhance the efficacy of immunotherapies. NPs present very different pharmacokinetic and pharmacodynamic properties compared with free drugs and enable the use of lower doses of immune-stimulating molecules, minimizing their side effects. However, NPs face issues concerning stability in physiological conditions, protein corona (PC) formation, and accumulation in the target tissue. PC formation changes the physicochemical and biological properties of the NPs and in consequence their therapeutic effect. This review summarizes the recent advances in the study of the effects of PC formation in NP-based immunotherapy. PC formation has complex effects on immunotherapy since it can diminish (“immune blinding”) or enhance the immune response in an uncontrolled manner (“immune reactivity”). Here, future perspectives of the field including the latest advances towards the use of personalized protein corona in cancer immunotherapy are also discussed.

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Acrylic Bone Cements Modified with Graphene Oxide: Mechanical, Physical, and Antibacterial Properties

Polymers ◽

10.3390/polym12081773 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1773 ◽

Cited By ~ 2

Author(s):

Mayra Eliana Valencia Zapata ◽

Lina Marcela Ruiz Rojas ◽

José Herminsul Mina Hernández ◽

Johannes Delgado-Ospina ◽

Carlos David Grande Tovar

Keyword(s):

Mechanical Properties ◽

Graphene Oxide ◽

Bacterial Infections ◽

Setting Time ◽

Antibacterial Properties ◽

Physical And Mechanical Properties ◽

Maximum Temperature ◽

Bone Cements ◽

Gram Negative ◽

Total Joint Replacements

Bacterial infections are a common complication after total joint replacements (TJRs), the treatment of which is usually based on the application of antibiotic-loaded cements; however, owing to the increase in antibiotic-resistant microorganisms, the possibility of studying new antibacterial agents in acrylic bone cements (ABCs) is open. In this study, the antibacterial effect of formulations of ABCs loaded with graphene oxide (GO) between 0 and 0.5 wt.% was evaluated against Gram-positive bacteria: Bacillus cereus and Staphylococcus aureus, and Gram-negative ones: Salmonella enterica and Escherichia coli. It was found that the effect of GO was dependent on the concentration and type of bacteria: GO loadings ≥0.2 wt.% presented total inhibition of Gram-negative bacteria, while GO loadings ≥0.3 wt.% was necessary to achieve the same effect with Gram-positives bacteria. Additionally, the evaluation of some physical and mechanical properties showed that the presence of GO in cement formulations increased wettability by 17%, reduced maximum temperature during polymerization by 19%, increased setting time by 40%, and increased compressive and flexural mechanical properties by up to 17%, all of which are desirable behaviors in ABCs. The formulation of ABC loading with 0.3 wt.% GO showed great potential for use as a bone cement with antibacterial properties.

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Bracken control by asulam

Proceedings of the Royal Society of Edinburgh Section B Biological Sciences ◽

10.1017/s0269727000003286 ◽

1982 ◽

Vol 81 (1-2) ◽

pp. 111-116

Author(s):

B. J. Heywood

Keyword(s):

Biological Properties ◽

Mineral Oils ◽

Selective Control ◽

Term Basis ◽

Short And Long Term

SynopsisThe chemical, physical and biological properties of asulam make this herbicide well suited for the selective control of bracken in various situations. These properties are reviewed and conditions considered to optimise the control of bracken and minimise the effect on the environment on both a short- and long-term basis.The role of surfactants and mineral oils is considered.

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π–π conjugations improve the long-term antibacterial properties of graphene oxide/quaternary ammonium salt nanocomposites

Chemical Engineering Journal ◽

10.1016/j.cej.2016.07.026 ◽

2016 ◽

Vol 304 ◽

pp. 873-881 ◽

Cited By ~ 33

Author(s):

Xiaoli Ye ◽

Xiaoming Qin ◽

Xueru Yan ◽

Junkang Guo ◽

Langhuan Huang ◽

...

Keyword(s):

Graphene Oxide ◽

Ammonium Salt ◽

Quaternary Ammonium ◽

Quaternary Ammonium Salt ◽

Antibacterial Properties

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The role of graphene oxide in limited long-term carbonation of cement-based matrix

Construction and Building Materials ◽

10.1016/j.conbuildmat.2018.02.082 ◽

2018 ◽

Vol 168 ◽

pp. 858-866 ◽

Cited By ~ 21

Author(s):

A. Mohammed ◽

J.G. Sanjayan ◽

A. Nazari ◽

N.T.K. Al-Saadi

Keyword(s):

Graphene Oxide

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Soil organic amendments for restoring degraded drylands: strategies, recommendations and challenges for large-scale application

10.5194/egusphere-egu2020-11867 ◽

2020 ◽

Author(s):

Paloma Hueso-Gonzalez ◽

Miriam Muñoz-Rojas

Keyword(s):

Organic Matter ◽

Large Scale ◽

Organic Amendments ◽

Renewable Resource ◽

Biological Properties ◽

Climatic Conditions ◽

Soil Restoration ◽

Application Rates

<p>Soil is an essential and non-renewable resource in natural and agricultural ecosystems with extremely slow formation and regeneration potential. In dryland areas, many ecosystems are being seriously affected by degradation processes because of an excessive use of agro-chemicals, deep tillage and intensive irrigation, among many other factors. The decline in soil organic matter is also becoming a major cause of soil degradation, particularly in dryland regions where low soil fertility cannot always maintain a sustainable production. The use of organic amendments in ecosystem restoration programs can be an effective technique for promoting soil restoration processes in degraded drylands and several studies have shown their bene&#64257;ts for improving soil physical, chemical and biological properties. This recovery is a result of the rapid increment of organic matter and clay contents in the soil in the short term. In the long-term, soil structure becomes more stable and water holding capacity, permeability and infiltration are improved, whereas surface runoff and erosion are reduced. Nevertheless, there are many research gaps in the knowledge of the effects of climatic conditions on their application, as well as the adequate types of amendment and doses and decomposition rates. In this presentation, we evaluate the role of organic amendments as an effective strategy in dryland restoration, highlighting the effects of different amendment types, doses and application rates. We will speci&#64257;cally address: (1) type of amendments and bene&#64257;ts arising from their use, (2) application methods and more appropriate doses and, (3) potential risk derivates for their application. We also showcase some recent case studies using organic amendments in degraded dryland areas from Spain and Australia.</p>

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The E-cigarette – a New Tool to Aid Smoking Cessation

European Respiratory & Pulmonary Diseases ◽

10.17925/erpd.2017.03.01.19 ◽

2017 ◽

Vol 03 (01) ◽

pp. 19

Author(s):

Pierre Bartsch ◽

Keyword(s):

Public Health ◽

Health Risks ◽

High Morbidity ◽

Public Health Community ◽

Potential Health ◽

The Public ◽

Quit Smoking ◽

Health Community

This editorial shows that, despite controversies in the public health community and among professionals regarding the role of e-cigarettes as an aid to stopping smoking, and although the potential health risks of long-term use of nicotine are unknown, modern devices should be regarded more as a solution than a problem. Clinicians, owing to the high morbidity and mortality of smoking should include e-cigarettes as efficient tools to help smokers to quit smoking or at least as a substitute for cigarettes. Effort is needed to improve knowledge about this tool.

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