Nanoparticle-induced chemoresistance: the emerging modulatory effects of engineered nanomaterials on human intestinal cancer cell redox metabolic adaptation.

The widespread use of engineered nanomaterials (ENMs) in food products necessitates the understanding of their impact on the gastrointestinal tract (GIT). Herein, we screened several representative food-borne comparator ENMs (i.e. ZnO, SiO2 and TiO2 nanoparticles (NPs)) and report that human colon cancer cells can insidiously exploit ZnO NP-induced adaptive response to acquire resistance against several chemotherapeutic drugs. By employing a conditioning and challenge treatment regime, we demonstrate that repeated exposure to a non-toxic dose of ZnO NPs (20 µM) could dampen the efficacy of cisplatin, paclitaxel and doxorubicin by 10-50% in monolayer culture and 3D spheroids of human colon adenocarcinoma cells. Structure-activity relationship studies revealed a complex interplay between nanoparticle surface chemistry and cell type in determining the chemoresistance-inducing effect, with silica coated ZnO NPs having a negligible influence on the anticancer treatment. Mechanistically, we showed that the pro-survival paracrine signaling was potentiated and propagated by a subset of ZnO NP "stressed" (Zn2++/ROS+) cells to the surrounding "bystander" (Zn2++/ROS-) cells. Transcriptome profiling, bioinformatics analysis and siRNA gene knockdown experiments revealed the nuclear factor erythroid 2-related factor 2 (Nrf2) as the key modulator of the ZnO NP-induced drug resistance. Our findings suggest that a ROS-inducing ENM can emerge as a nano-stressor, capable of regulating the chemosensitivity of colon cancer cells.

Benefits and Conflicts: A Systematic Review of Dog Park Design and Management Strategies.

Dog ownership and dog walking brings various health benefits for urban dwellers, especially since the COVID-19 pandemic, but trigger a number of controversies. Dog parks have become increasingly significant public resources in the pandemic to support these benefits while facing intense conflicts. To develop effective dog parks in urban settings, growing numbers of scholars have provided insights into the design and management strategies for addressing the benefits and conflicts. The objective of this study is to synthesize and analyze various aspects of dog park design and management and to assess identified strategies for enhancing their benefits while mitigating their drawbacks. Following the PRISMA guidelines, a systematic study was conducted to synthesize the benefits, conflicts, and management strategies of dog parks, supported by Citespace. Benefits and conflicts in dog park design and management have been synthesized and organized according to their frequency of presence and the statistical results. We analyzed and assessed existing design and management strategies. Through this systematic study, we discovered the need obtain o po experimental evidence on effective dog park design and management to enhance their benefits while mitigating their sources of conflict and limitations in the intensity of park visitors' physical activity in off-leash areas. Guidelines for the design and management strategies for effective dog parks were made to enhance their benefits while alleviating conflicts in the future development of sustainable dog parks that promote healthy relationships between canines and residents in urban built environments.

Printer center nanoparticles alter the DNA repair capacity of human bronchial airway epithelial cells.

Nano-enabled, toner-based printing equipment emit nanoparticles during operation. The bioactivity of these nanoparticles as documented in a plethora of published toxicological studies raises concerns about their potential health effects. These include pro-inflammatory effects that can lead to adverse epigenetic alterations and cardiovascular disorders in rats. At the same time, their potential to alter DNA repair pathways at realistic doses remains unclear. In this study, size-fractionated, airborne particles from a printer center in Singapore were sampled and characterized. The PM0.1 size fraction (particles with an aerodynamic diameter less than 100 nm) of printer center particles (PCP) were then administered to human lung adenocarcinoma (Calu-3) or lymphoblastoid (TK6) cells. We evaluated plasma membrane integrity, mitochondrial activity, and intracellular reactive oxygen species (ROS) generation. Moreover, we quantified DNA damage and alterations in the cells' capacity to repair 6 distinct types of DNA lesions. Results show that PCP altered the ability of Calu-3 cells to repair 8oxoG:C lesions and perform nucleotide excision repair, in the absence of acute cytotoxicity or DNA damage. Alterations in DNA repair capacity have been correlated with the risk of various diseases, including cancer, therefore further genotoxicity studies are needed to assess the potential risks of PCP exposure, at both occupational settings and at the end-consumer level.

Microbial resistance to nanotechnologies: An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants.

Microbial resistance to current antibiotics therapies is a major cause of implant failure and adverse clinical outcomes in orthopaedic surgery. Recent developments in advanced antimicrobial nanotechnologies provide numerous opportunities to effective remove resistant bacteria and prevent resistance from occurring through unique mechanisms. With tunable physicochemical properties, nanomaterials can be designed to be bactericidal, antifouling, immunomodulating, and capable of delivering antibacterial compounds to the infection region with spatiotemporal accuracy. Despite its substantial advancement, an important, but under-explored area, is potential microbial resistance to nanomaterials and how this can impact the clinical use of antimicrobial nanotechnologies. This review aims to provide a better understanding of nanomaterial-associated microbial resistance to accelerate bench-to-bedside translations of emerging nanotechnologies for effective control of implant associated infections.

Direct reuse of electronic plastic scraps from computer monitor and keyboard to direct stem cell growth and differentiation.

Reuse of electronic wastes is a critical aspect for a more sustainable circular economy as it provides the simplest and most direct route to extend the lifespan of non-renewable resources. Herein, the distinctive surface and micro topographical features of computer electronic-plastic (E-plastic) scraps were unconventionally repurposed as a substrate material to guide the growth and differentiation of human adipose-derived mesenchymal stem cells (ADSCs). Specifically, the E-plastics were scavenged from discarded computer components such as light diffuser plate (polyacrylates), prismatic sheet (polyethylene terephthalate), and keyboards (acrylonitrile butadiene styrene) were cleaned, sterilized, and systematically characterized to determine the identity of the plastics, chemical constituents, surface features, and leaching characteristics. Multiparametric analysis revealed that all the E-plastics could preserve stem-cell phenotype and maintain cell growth over 2 weeks, rivalling the performance of commercial tissue-culture treated plates as cell culture plastics. Interestingly, compared to commercial tissue-culture treated plastics and in a competitive adipogenic and osteogenic differentiation environment, ADSCs cultured on the keyboard and light diffuser plastics favoured bone cells formation while the grating-like microstructures of the prismatic sheet promoted fat cells differentiation via the process of contact guidance. Our findings point to the real possibility of utilizing discarded computer plastics as a "waste-to-resource" material to programme stem cell fate without further processing nor biochemical modification, thus providing an innovative second-life option for E-plastics from personal computers.

Diatom-inspired 2D nitric oxide releasing anti-infective porous nanofrustules.

Two-dimensional (2D) nanomaterials (NM) have emerged as promising platforms for antibacterial applications. However, the inherent "flatness" of 2D NM often limits the loading of antimicrobial components needed for synergistic bactericidal actions. Here, inspired by the highly ornamented siliceous frustules of diatoms, we prepared 2D ultrathin (<20 nm) and rigid "nanofrustule" plates via the out-of-plane growth of cetyltrimethylammonium bromide (CTAB) directed silica mesostructures on the surfaces of 2D graphene oxide nanosheets. The nanofrustules were characterized by the presence of mesoporous channels with a pore size of 3 nm and a high specific surface area of 674 m2 g-1. S-nitrosothiol-modification on the silica surfaces enables the development of a novel anti-infective nitric oxide (NO) releasing NO-nanofrustule system. The cage-like mesoporous silica architecture enabled a controlled and sustainable release of NO from the NO-nanofrustules under physiological conditions. The NO-nanofrustules displayed broad antibacterial effects against Staphylococcus aureus and Escherichia coli with a minimum inhibitory concentration of 250 µg ml-1. Mechanistic studies revealed that the antibacterial property of NO-nanofrustules was attained via a unique "capture-and-release" mode-of-action. The first step entailed the capture of the bacteria by the NO-nanofrustules to form micro-aggregates. This was followed by the release of high levels of NO to the captured bacteria to elicit a potent anti-infective effect. In combination with the lack of cytotoxicity in human dermal cells, the 2D hybrid NO-nanofrustules may be utilized to combat wound infections in clinical settings.

Potent-By-Design: Amino Acids Mimicking Porous Nanotherapeutics with Intrinsic Anticancer Targeting Properties.

Exogenous sources of amino acids are essential nutrients to fuel cancer growth. Here, the increased demand for amino acid displayed by cancer cells is unconventionally exploited as a design principle to replete cancer cells with apoptosis inducing nanoscopic porous amino acid mimics (Nano-PAAM). A small library consisting of nine essential amino acids nanoconjugates (30 nm) are synthesized, and the in vitro anticancer activity is evaluated. Among the Nano-PAAMs, l-phenylalanine functionalized Nano-PAAM (Nano-pPAAM) has emerged as a novel nanotherapeutics with excellent intrinsic anticancer and cancer-selective properties. The therapeutic efficacy of Nano-pPAAM against a panel of human breast, gastric, and skin cancer cells could be ascribed to the specific targeting of the overexpressed human large neutral amino acid transporter SLC7A5 (LAT-1) in cancer cells, and its intracellular reactive oxygen species (ROS) inducing properties of the nanoporous core. At the mechanistic level, it is revealed that Nano-pPAAM could activate both the extrinsic and intrinsic apoptosis pathways to exert a potent "double-whammy" anticancer effect. The potential clinical utility of Nano-pPAAM is further investigated using an MDA-MB-231 xenograft in NOD scid gamma mice, where an overall suppression of tumor growth by 60% is achieved without the aid of any drugs or application of external stimuli.

Repurposing of Fruit Peel Waste as a Green Reductant for Recycling of Spent Lithium-Ion Batteries.

The development of environmentally benign hydrometallurgical processes to treat spent lithium-ion batteries (LIBs) is a critical aspect of the electronic-waste circular economy. Herein, as an alternative to the highly explosive H2O2, discarded orange peel powder (OP) is valorized as a green reductant for the leaching of industrially produced LIBs scraps in citric acid (H3Cit) lixiviant. The reductive potential of the cellulose- and antioxidant-rich OP was validated using the 3,5-dinitrosalicylic acid and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid assays. Leaching parameters such as OP concentration (200 mg), processing temperature (100 °C), H3Cit concentration (1.5 M), reaction duration (4 h), and slurry density (25 g/mL) were systematically optimized to achieve 80-99% leaching efficiencies of Ni, Mn, Co, and Li from the LIB "black mass". Importantly, solid side-streams generated by the OP-enabled leaching displayed negligible cytotoxicity in three different human cell lines, suggesting that the process is environmentally safe. As a proof of concept, Co(OH)2 was selectively recovered from the green lixiviant and subsequently utilized to fabricate new batches of LiCoO2 (LCO) coin cell batteries. Galvanostatic charge-discharge test revealed that the regenerated batteries exhibited initial charge and discharge values of 120 and 103 mAh/g, respectively, which is comparable to the performance of commercial LCO batteries. The use of fruit peel waste to recover valuable metals from spent LIBs is an effective, ecofriendly, and sustainable strategy to minimize the environmental footprint of both waste types.

Inflammation Increases Susceptibility of Human Small Airway Epithelial Cells to Pneumonic Nanotoxicity.

Exposure to inhaled anthropogenic nanomaterials (NM) with dimension <100 nm has been implicated in numerous adverse respiratory outcomes. Although studies have identified key NM physiochemical determinants of pneumonic nanotoxicity, the complex interactive and cumulative effects of NM exposure, especially in individuals with preexisting inflammatory respiratory diseases, remain unclear. Herein, the susceptibility of primary human small airway epithelial cells (SAEC) exposed to a panel of reference NM, namely, CuO, ZnO, mild steel welding fume (MSWF), and nanofractions of copier center particles (Nano-CCP), is examined in normal and tumor necrosis factor alpha (TNF-α)-induced inflamed SAEC. Compared to normal SAEC, inflamed cells display an increased susceptibility to NM-induced cytotoxicity by 15-70% due to a higher basal level of intracellular reactive oxygen species (ROS). Among the NM screened, ZnO, CuO, and Nano-CCP are observed to trigger an overcompensatory response in normal SAEC, resulting in an increased tolerance against subsequent oxidative insults. However, the inflamed SAEC fails to adapt to the NM exposure due to an impaired nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated cytoprotective response. The findings reveal that susceptibility to pulmonary nanotoxicity is highly dependent on the interplay between NM properties and inflammation of the alveolar milieu.

A Tag-Based Affinity Purification Mass Spectrometry Workflow for Systematic Isolation of the Human Mitochondrial Protein Complexes.

Mitochondria (mt) are double-membraned, dynamic organelles that play an essential role in a large number of cellular processes, and impairments in mt function have emerged as a causative factor for a growing number of human disorders. Given that most biological functions are driven by physical associations between proteins, the first step towards understanding mt dysfunction is to map its protein-protein interaction (PPI) network in a comprehensive and systematic fashion. While mass-spectrometry (MS) based approaches possess the high sensitivity ideal for such an endeavor, it also requires stringent biochemical purification of bait proteins to avoid detecting spurious, non-specific PPIs. Here, we outline a tagging-based affinity purification coupled with mass spectrometry (AP-MS) workflow for discovering new mt protein associations and providing novel insights into their role in mt biology and human physiology/pathology. Because AP-MS relies on the creation of proteins fused with affinity tags, we employ a versatile-affinity (VA) tag, consisting of 3× FLAG, 6 × His, and Strep III epitopes. For efficient delivery of affinity-tagged open reading frames (ORF) into mammalian cells, the VA-tag is cloned onto a specific ORF using Gateway recombinant cloning, and the resulting expression vector is stably introduced in target cells using lentiviral transduction. In this chapter, we show a functional workflow for mapping the mt interactome that includes tagging, stable transduction, selection and expansion of mammalian cell lines, mt extraction, identification of interacting protein partners by AP-MS, and lastly, computational assessment of protein complexes/PPI networks.

Human keratinocytes adapt to ZnO nanoparticles induced toxicity via complex paracrine crosstalk and Nrf2-proteasomal signal transduction.

Zinc oxide nanoparticles (Nano-ZnO) is currently one of the most extensively used inorganic particles in a wide range of skin care and consumable products. Therefore, examining the biological effects of Nano-ZnO, especially in the non-cytotoxic levels, thus holds important contemporary practical implications. Herein, our study demonstrates that long-term conditioning of human keratinocytes (HaCaTs) to non-cytoxic dose of Nano-ZnO (∼100 nm) can induce an adaptive response, leading to an enhancement of the cells tolerance against cytotoxic level of Nano-ZnO. It was found that the Nano-ZnO induced adaptive alteration is mediated by a strong synergism between the generation of reactive oxygen species (ROS) flares by a sub-population of cells that are loaded with Nano-ZnO and upregulation of several pro-inflammatory transcripts. Further studies revealed activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) stress response pathway and the associated downstream sustained augmented level of chymotrypsin-like 20 s proteasome activity to be the major mechanism underpinning this phenomenon. Interestingly, these cytoprotective responses can further aid the Nano-ZnO conditioned HaCaT cells to cross-adapt to harmful effects of ultraviolet-A (UVA) by reducing radiation-induced DNA damage. Our findings have unveiled a range of previously undocumented potent and exploitable bioeffects of Nano-ZnO induced ROS mediated signaling within the framework of nano-adaptation.

Molecular Design and Medicinal Applications of Nano-Nitric Oxide Delivery Systems.

BACKGROUND: Nitric oxide (NO) plays important regulatory roles in a plethora of biological functions and thus holds tremendous potential to be exploited for clinical uses. However, the chemistries in the molecular design of nano-nitric oxide delivery systems is currently lacking. OBJECTIVE: The overarching aim of this review is to provide the readers with the fundamentals that relate to the design of NO release molecules (NORMs), loading and releasing mechanism, as well as delivery of NORMs for nanotherapeutics. METHODS: We conducted a thorough literature search on the design and synthesis of NORMs, as well as the current state-of-the-art NO compatible delivery platforms to address various clinical needs. RESULTS: N-diazeniumdiolate and S-nitrosothiol based NO molecules are among the most widely used NORMs for anti-cancer and anti-microbial applications. The innovative integration of these NORMs with cytocompatible organic and inorganic nanocarriers enabled controlled spatiotemporal delivery and release of NO at the targeted diseased sites. CONCLUSION: We have provided a comprehensive summary of the fundamental chemistries underpinning the molecular design of the NORMs and critically assessed the recent advancements of nano-NO delivery systems for advanced biomedical applications.

A Map of Human Mitochondrial Protein Interactions Linked to Neurodegeneration Reveals New Mechanisms of Redox Homeostasis and NF-κB Signaling.

Mitochondrial protein (MP) dysfunction has been linked to neurodegenerative disorders (NDs); however, the discovery of the molecular mechanisms underlying NDs has been impeded by the limited characterization of interactions governing MP function. Here, using mass spectrometry (MS)-based analysis of 210 affinity-purified mitochondrial (mt) fractions isolated from 27 epitope-tagged human ND-linked MPs in HEK293 cells, we report a high-confidence MP network including 1,964 interactions among 772 proteins (>90% previously unreported). Nearly three-fourths of these interactions were confirmed in mouse brain and multiple human differentiated neuronal cell lines by primary antibody immunoprecipitation and MS, with many linked to NDs and autism. We show that the SOD1-PRDX5 interaction, critical for mt redox homeostasis, can be perturbed by amyotrophic lateral sclerosis-linked SOD1 allelic variants and establish a functional role for ND-linked factors coupled with IκBɛ in NF-κB activation. Our results identify mechanisms for ND-linked MPs and expand the human mt interaction landscape.