Cerium oxide nanoparticles: green synthesis and biological applications

CeO2 nanoparticles (NPs) have shown promising approaches as therapeutic agents in biology and medical sciences. The physicochemical properties of CeO2-NPs, such as size, agglomeration status in liquid, and surface charge, play important roles in the ultimate interactions of the NP with target cells. Recently, CeO2-NPs have been synthesized through several bio-directed methods applying natural and organic matrices as stabilizing agents in order to prepare biocompatible CeO2-NPs, thereby solving the challenges regarding safety, and providing the appropriate situation for their effective use in biomedicine. This review discusses the different green strategies for CeO2-NPs synthesis, their advantages and challenges that are to be overcome. In addition, this review focuses on recent progress in the potential application of CeO2-NPs in biological and medical fields. Exploiting biocompatible CeO2-NPs may improve outcomes profoundly with the promise of effective neurodegenerative therapy and multiple applications in nanobiotechnology

Engineering next-generation bioinks with nanoparticles: moving from reinforcement fillers to multifunctional nanoelements

The application of additive manufacturing in the biomedical field has become a hot topic in the last decade owing to its potential to provide personalized solutions for patients. Different bioinks have been designed trying to obtain a unique concoction that addresses all the needs for tissue engineering and drug delivery purposes, among others. Despite the remarkable progress made, the development of suitable bioinks which combine printability, cytocompatibility, and biofunctionality is still a challenge. In this sense, the well-established synthetic and functionalization routes to prepare nanoparticles with different functionalities make them excellent candidates to be combined with polymeric systems in order to generate suitable multi-functional bioinks. In this review, we briefly discuss the most recent advances in the design of functional nanocomposite hydrogels considering their already evaluated or potential use as bioinks. The scientific development over the last few years is reviewed, focusing the discussion on the wide range of functionalities that can be incorporated into 3D bioprinted constructs through the addition of multifunctional nanoparticles in order to increase their regenerative potential in the field of tissue engineering.Authors acknowledge financial support from the ERC Grant CoG MagTendon nr 772817; FCT – Fundação para a Ciência e a Tecnologia for the PhD grant of SMB (PD/BD/129403/2017), for the contract to MGF (CEECIND/01375/2017); and for project SmarTendon (PTDC/NAN-MAT/30595/2017). AP is grateful to Xunta de Galicia for his postdoctoral grant ED481B2019/025. Some figures were created with BioRender.com

A framework for time studies in urban planning: Assessment of comprehensive planning in the case of Tehran

The contemporary comprehensive urban planning in Iran suffers from lack of mechanisms for accountability and monitoring, as well as weak implementation. In response, in the Comprehensive Plan of Tehran, developed in 2007, evaluation and monitoring gained new significance, however, a gap remaining about temporal aspects. This article proposes some criteria of so-called time-oriented policies for evaluating planning practices, through a specific analytical framework. Despite development of theory on time-oriented approach in Europe, such an evaluative framework for plans had not been developed yet. The proposed ‘urban temporal studies framework’ consists of two main groups of attributes: surveying ‘time orders’ such as urban rhythms under descriptive part and considering major normative principles of ‘ordering time’ such as temporal equity, efficiency and institutionalisation. Using a content-analysis methodology, we have applied the proposed framework evaluating the recent Comprehensive Plan of Tehran. The results of the analysis indicate that the planning system in Tehran has mostly considered normative temporal aspects and they are mainly implicit in the plan. The frequent considerations of temporal organisation in our case clarify the strength of ‘planning in time’, occurred implicitly in this plan. On the other hand, the absence of descriptive elements in the plan notices a lack in awareness or a weak interest of planners and decision makers in Tehran about social structure of time of the city

Cerium oxide nanoparticles: green synthesis and biological applications

Fahimeh Charbgoo,1 Mansor Bin Ahmad,2,* Majid Darroudi3,* 1Department of Pharmaceutical Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran; 2Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 3Nuclear Medicine Research Center, Mashhad University of Medical Sciences, Mashhad, Iran *These authors contributed equally to this work Abstract: CeO2 nanoparticles (NPs) have shown promising approaches as therapeutic agents in biology and medical sciences. The physicochemical properties of CeO2-NPs, such as size, agglomeration status in liquid, and surface charge, play important roles in the ultimate interactions of the NP with target cells. Recently, CeO2-NPs have been synthesized through several bio-directed methods applying natural and organic matrices as stabilizing agents in order to prepare biocompatible CeO2-NPs, thereby solving the challenges regarding safety, and providing the appropriate situation for their effective use in biomedicine. This review discusses the different green strategies for CeO2-NPs synthesis, their advantages and challenges that are to be overcome. In addition, this review focuses on recent progress in the potential application of CeO2-NPs in biological and medical fields. Exploiting biocompatible CeO2-NPs may improve outcomes profoundly with the promise of effective neurodegenerative therapy and multiple applications in nanobiotechnology. Keywords: cerium oxide nanoparticles, green synthesis, biocompatibility, surface Ce3+, size, morpholog

Gold nanoparticle should understand protein corona for being a clinical nanomaterial

Gold nanoparticles (AuNPs) have attracted great attention in biomedical fields due to their unique properties. However, there are few reports on clinical trial of these nanoparticles. In vivo, AuNPs face complex biological fluids containing abundant proteins, which challenge the prediction of their fate that is known as "bio-identity". These proteins attach onto the AuNPs surface forming protein corona that makes the first step of nano-bio interface and dictates the subsequent AuNPs fate. Protein corona formation even stealth active targeting effect of AuNPs. Manipulating the protein corona identity based on the researcher goal is the way to employ corona to achieve maximum effect in therapy or other applications. In this review, we provide details on the biological identity of AuNPs under various environmental- and/or physiological conditions. We also highlight how the particular corona can direct the biodistribution of AuNPs. We further discuss the strategies available for controlling or reducing corona formation on AuNPs surface and achieving desired effects using AuNPs in vivo by engineering protein corona on their surface