A redox-responsive nanosystem to suppress chemoresistant lung cancer through targeting STAT3.

Cancer stem cells (CSCs) have been demonstrated to be involved in tumor initiation and relapse, and the presence of CSCs in the tumor tissue often leads to therapeutic failure. BBI608 has been identified to eliminate CSCs by inhibiting signal transducer and activator of transcription 3 (STAT3). In this study, we confirm that BBI608 can efficiently suppress the proliferation and migration of non-small cell lung cancer (NSCLC) cells, and specifically kill the stemness-high population in chemoresistant NSCLC cells. To improve its bioavailability and tumor accumulation, BBI608 is successfully encapsulated into redox-responsive PEGylated branched N-(2-hydroxypropyl) methacrylamide (HPMA)-deoxy cholic acid (DA) polymeric nanoparticles (BBI608-SS-NPs). The BBI608-SS-NPs can release the drug in response to high concentrations of intracellular glutathione, and exhibit cytotoxicity against lung cancer cells and CSCs comparable to the free drug BBI608. Furthermore, the BBI608-SS-NPs preferentially accumulate in tumor sites, resulting in a superior anti-tumor efficacy in both cisplatin-resistant cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models of NSCLC. Mechanistic studies demonstrate that BBI608-SS-NPs not only directly inhibit the downstream genes of the STAT3 pathway, but also indirectly inhibit the Wnt pathway. Overall, this stimuli-responsive polymeric nanoformulation of BBI608 shows great potential in the treatment of chemoresistant NSCLC by targeting CSCs.

Prophylactic use amphotericin B use in patients with hematologic disorders complicated by neutropenia: a systematic review and meta-analysis.

The purpose of this study is to evaluate the efficacy of prophylactic use amphotericin B in patients with hematologic disorders complicated by neutropenia. We searched the PubMed, EMBASE, The Cochrane Library, CBM, CNKI, VIP and WanFang Data database and the China Clinical Trials Registry ( www.chictr.org.cn ) to collect randomized controlled trials (RCTs) of amphotericin B for patients with hematologic disorders complicated by neutropenia from inception to May 2023. The Cochrane risk-of-bias tool for RCTs was used to assess the bias risk of the included studies. The meta-analysis was performed using RevMan 5.3 software. A total of 6 studies with a total of 1019 patients were included. The results of the meta-analysis showed that the treatment group was superior to the control group in terms of the fungal infection rate, and the differences were statistically significant [RR = 0.47, 95% CI (0.32, 0.69), P < 0.0001]. There was no significant difference between the two groups in terms of the mortality [RR = 0.87, 95% CI (0.61, 1.23), P = 0.43] and the incidence of colonization [OR = 0.51, 95% CI (0.25, 1.03), P = 0.06]. The evidence shows that amphotericin B prophylactic use for patients with hematologic disorders complicated by neutropenia can decrease the fungal infection rate. However, there was no significant difference in reducing mortality or the incidence of colonization. Due to the limited quality and quantity of the included studies, more high-quality studies are needed to verify the above conclusion.

Prevalence of Use of Potentially Inappropriate Medications Among Older Adults Worldwide: A Systematic Review and Meta-Analysis.

Importance: The use of potentially inappropriate medications (PIMs) is widespread yet continues to receive little attention in outpatient services. Objective: To estimate the overall prevalence of PIM use in outpatient services. Data Sources: PubMed, Embase, and Web of Science were searched to identify relevant studies published from January 1, 1990, to November 21, 2022. Study Selection: Observational studies that reported the prevalence of PIM use among older patients in outpatient services were screened. Data Extraction and Synthesis: Two reviewers independently selected eligible articles, extracted data, and assessed the risk of bias. A random-effects meta-analysis was conducted to pool the prevalence estimates. Main Outcomes and Measures: The global patterns in the prevalence of PIM use among older patients in outpatient services were estimated, and the temporal trends and regional differences in PIM use were investigated. Results: A total of 94 articles with 132 prevalence estimates were analyzed, including nearly 371.2 million older participants from 17 countries. Overall, the pooled prevalence of PIM use was 36.7% (95% CI, 33.4%-40.0%). Africa had the highest prevalence of PIM use (47.0%; 95% CI, 34.7%-59.4%), followed by South America (46.9%; 95% CI, 35.1%-58.9%), Asia (37.2%; 95% CI, 32.4%-42.2%), Europe (35.0%; 95% CI, 28.5%-41.8%), North America (29.0%; 95% CI, 22.1%-36.3%), and Oceania (23.6%; 95% CI, 18.8%-28.8%). In addition, the prevalence of PIM use is highest in low-income areas. Use of PIMs among older patients has become increasingly prevalent in the past 2 decades. Conclusions and Relevance: This study of patterns of PIM use by different groups, such as geographic regions and World Bank countries, suggests noticeable geographic environment and economic income differences in the burden of PIMs in outpatient services. Furthermore, the high prevalence trend in the past 2 decades indicates that the global burden of PIM use continues to be worthy of attention.

Diversity-oriented synthesis of diterpenoid alkaloids yields a potent anti-inflammatory agent.

BACKGROUND: The diterpenoid alkaloids belong to a highly esteemed group of natural compounds, which display significant biological activities. It is a productive strategy to expand the chemical space of these intriguing natural compounds for drug discovery. METHODS: We prepared a series of new derivatives bearing diverse skeletons and functionalities from the diterpenoid alkaloids deltaline and talatisamine based on a diversity-oriented synthesis strategy. The anti-inflammatory activity of these derivatives was initially screened and evaluated by the release of nitric oxide (NO), tumor necrosis factor (TNF-α), and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-activated RAW264.7 cells. Futhermore, the anti-inflammatory activity of the representative derivative 31a was validated in various inflammatory animal models, including phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mice ear edema, LPS-stimulated acute kidney injury, and collagen-induced arthritis (CIA). RESULTS: It was found that several derivatives were able to suppress the secretion of NO, TNF-α, and IL-6 in LPS-activated RAW264.7 cells. Compound 31a, one of the representative derivatives named as deltanaline, demonstrated the strongest anti-inflammatory effects in LPS-activated macrophages and three different animal models of inflammatory diseases by inhibiting nuclear factor kappa-B (NF-κB)/mitogen-activated protein kinase (MAPK) signaling and inducing autophagy. CONCLUSION: Deltanaline is a new structural compound derived from natural diterpenoid alkaloids, which may serve as a new lead compound for the treatment of inflammatory diseases.

Efficacy and Safety of Molnupiravir Treatment for COVID-19: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

INTRODUCTION: There are currently some differences in the research results of molnupiravir. This study aimed to evaluate the efficacy and safety of molnupiravir in the treatment of COVID-19. METHODS: PubMed, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), ClinicalTrials.gov, ICTRP (International Clinical Trials Registry Platform) and medRxiv were searched to identify relevant randomised controlled trials (RCTs) from inception to 1 January 2023. The Cochrane risk of bias tool for randomised trials was used to assess the bias risk of the included studies. Revman 5.4 software was used for meta-analysis. RESULTS: Nine RCTs were included, including 31 573 COVID-19 patients, of whom 15 846 received molnupiravir. The meta-analysis results showed that the molnupiravir group had a higher proportion in terms of clinical improvement (Day 5 RR 2.41, 95% CI 1.18-4.92; Day 10 RR 1.45, 95% CI 1.04-2.01) and real-time polymerase chain reaction negativity (Day 5 RR 2.78, 95% CI 1.38-5.62; Day 10 RR 1.18, 95% CI 1.07-1.31). However, no significant difference was observed between the two groups in terms of mortality, hospitalisation, adverse events and serious adverse events. CONCLUSIONS: Molnupiravir can accelerate the rehabilitation of COVID-19 patients, but it does not significantly reduce mortality and hospitalisation.

Nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients: A systematic review and meta-analysis.

At present, there are some differences in the research results of nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients. We aimed to evaluate the efficacy and safety of nirmatrelvir-ritonavir compared with other antiviral drugs and the impact of different antiviral drugs on the short- and long-term effects of COVID-19. PubMed, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), Web of Science, Google Scholar, and MedRxiv were searched to identify relevant studies from inception to March 30, 2023. We conducted a meta-analysis to estimate the effects of nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients and safety outcomes. The RoB1 and ROBINS-I were used to assess the bias risk of the included studies. Revman 5.4 software was used for meta-analysis (PROSPERO Code No: CRD42023397816). Twelve studies were included, including 30 588 COVID-19 patients, of whom 13 402 received nirmatrelvir-ritonavir. The meta-analysis results showed that the nirmatrelvir-ritonavir group had a lower proportion of patients than the control group in terms of long-term mortality (odds ratio [OR] = 0.29, 95% confidence interval [CI]: 0.13-0.66), hospitalization (OR = 0.44, 95% CI: 0.37-0.53, short term; OR = 0.52, 95% CI: 0.36-0.77, long term), and disease progression (OR = 0.56, 95% CI: 0.38-0.83, short term; OR = 0.60, 95% CI: 0.48-0.74, long term), and nirmatrelvir ritonavir showed little difference in safety compared to the control group. Nirmatrelvir-ritonavir can reduce the mortality and hospitalization of COVID-19 patients compared with other antiviral drugs. Further large-scale studies remain to validate these findings.

Mitochondria-Targeting and Multiresponsive Nanoplatform Based on AIEgens for Synergistic Chemo-Photodynamic Therapy and Enhanced Immunotherapy.

Although photodynamic therapy (PDT) has become an attractive strategy for cancer treatment, its clinical application still suffers from some limitations, including insufficient delivery of photosensitizers, hypoxic tumor environment, and the development of PDT resistance. To address these limitations, a new class of mitochondria-targeting and fluorinated polymer with aggregation-induced emission characteristics was fabricated to sensitize PDT and co-deliver chemotherapeutic drugs. The amphiphilic fluoropolymer was able to efficiently carry oxygen and SN-38 (the active metabolite of irinotecan) and self-assemble into multifunctional micellar nanoparticles (SN-38-TTCF@O2 NPs). Upon internalization into tumor cells, these NPs could successfully escape lysosomes, selectively target mitochondria, efficiently produce reactive oxygen species (ROS) under light irradiation, and release drugs in response to ROS. In the HCT116 tumor xenograft model, they preferentially accumulated in tumor tissue and significantly alleviated tumor hypoxia, resulting in synergistic chemo-PDT efficacy without distinct toxicity. Furthermore, the nanoscale chemo-PDT induced immunogenic cell death, promoted the recruitment and activation of cytotoxic T lymphocytes, and ultimately augmented the anti-tumor efficacy of anti-PD-1 antibody in the murine CT26 tumor model. These results may provide novel insights into the development of efficient chemo-PDT nanomedicine to improve the outcome of immunotherapy.

SUMOylation facilitates the assembly of a Nuclear Factor-Y complex to enhance thermotolerance in Arabidopsis.

Heat stress (HS) has serious negative effects on plant development and has become a major threat to agriculture. A rapid transcriptional regulatory cascade has evolved in plants in response to HS. Nuclear Factor-Y (NF-Y) complexes are critical for this mechanism, but how NF-Y complexes are regulated remains unclear. In this study, we identified NF-YC10 (NF-Y subunit C10), a central regulator of the HS response in Arabidopsis thaliana, as a substrate of SUMOylation, an important post-translational modification. Biochemical analysis showed that the SUMO ligase SIZ1 (SAP AND MIZ1 DOMAIN-CONTAINING LIGASE1) interacts with NF-YC10 and enhances its SUMOylation during HS. The SUMOylation of NF-YC10 facilitates its interaction with and the nuclear translocation of NF-YB3, in which the SUMO interaction motif (SIM) is essential for its efficient association with NF-YC10. Further functional analysis indicated that the SUMOylation of NF-YC10 and the SIM of NF-YB3 are critical for HS-responsive gene expression and plant thermotolerance. These findings uncover a role for the SIZ1-mediated SUMOylation of NF-YC10 in NF-Y complex assembly under HS, providing new insights into the role of a post-translational modification in regulating transcription during abiotic stress responses in plants.

Nanoparticle-Mediated Delivery of STAT3 Inhibitors in the Treatment of Lung Cancer.

Lung cancer is a common malignancy worldwide, with high morbidity and mortality. Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor that not only regulates different hallmarks of cancer, such as tumorigenesis, cell proliferation, and metastasis but also regulates the occurrence and maintenance of cancer stem cells (CSCs). Abnormal STAT3 activity has been found in a variety of cancers, including lung cancer, and its phosphorylation level is associated with a poor prognosis of lung cancer. Therefore, the STAT3 pathway may represent a promising therapeutic target for the treatment of lung cancer. To date, various types of STAT3 inhibitors, including natural compounds, small molecules, and gene-based therapies, have been developed through direct and indirect strategies, although most of them are still in the preclinical or early clinical stages. One of the main obstacles to the development of STAT3 inhibitors is the lack of an effective targeted delivery system to improve their bioavailability and tumor targetability, failing to fully demonstrate their anti-tumor effects. In this review, we will summarize the recent advances in STAT3 targeting strategies, as well as the applications of nanoparticle-mediated targeted delivery of STAT3 inhibitors in the treatment of lung cancer.

Impact of the expert consensus on polypharmacy and potentially inappropriate medication use in elderly lung cancer outpatients with multimorbidity: An interrupted time series analysis, 2016-2021.

Objectives: Elderly lung cancer patients often have chronic diseases other than lung cancer. Therefore, this kind of population is often accompanied by polypharmacy. This situation and the resulting potentially inappropriate medication (PIM) use are an increasing global concern. In this context, the Chinese Association of Geriatric Research issued an expert consensus on the safety management of polypharmacy. However, the long- and short-term effects of the expert consensus on polypharmacy and PIM use are not clear. Methods: The study was conducted in Chengdu, a city in southwestern China, consisting of prescriptions for elderly lung cancer outpatients with multimorbidity (cancer with other diseases) from January 2016 to December 2021. The 2019 Beers criteria were used to evaluate PIM use, and interrupted time series analysis was used to evaluate the longitudinal effectiveness of expert consensus by measuring the prevalence of polypharmacy and PIM use. We used R software version 4.2.0 for data analysis. Results: A total of 7,238 elderly lung cancer outpatient prescriptions were included in the study. After the publication of the expert consensus, the level (ß = -10.273, P < 0.001) of the prevalence of polypharmacy decreased, but the trend (ß = 0.158, p = 0.855) of polypharmacy increased. The prevalence of PIM use decreased abruptly (ß = -22.828, p < 0.001) after the intervention, but the long-term trend was still upward (ß = 0.907, p = 0.916). Conclusion: The long-term effects of the publication of the expert consensus on the prevalence of polypharmacy and PIM use in hospitals in Chengdu were not optimal. Future research on interventions rationing polypharmacy and PIM use is needed.

Targeted Drug/Gene/Photodynamic Therapy via a Stimuli-Responsive Dendritic-Polymer-Based Nanococktail for Treatment of EGFR-TKI-Resistant Non-Small-Cell Lung Cancer.

Yes-associated protein (YAP) has been identified as a key driver for epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) resistance. Inhibition of YAP expression could be a potential therapeutic option for treating non-small-cell lung cancer (NSCLC). Herein, a nanococktail therapeutic strategy is proposed by employing amphiphilic and block-dendritic-polymer-based nanoparticles (NPs) for targeted co-delivery of EGFR-TKI gefitinib (Gef) and YAP-siRNA to achieve a targeted drug/gene/photodynamic therapy. The resulting NPs are effectively internalized into Gef-resistant NSCLC cells, successfully escape from late endosomes/lysosomes, and responsively release Gef and YAP-siRNA in an intracellular reductive environment. They preferentially accumulate at the tumor site after intravenous injection in both cell-line-derived xenograft (CDX) and patient-derived xenograft (PDX) models of Gef-resistant NSCLC, resulting in potent antitumor efficacy without distinct toxicity after laser irradiation. Mechanism studies reveal that the cocktail therapy could block the EGFR signaling pathway with Gef, inhibit activation of the EGFR bypass signaling pathway via YAP-siRNA, and induce tumor cell apoptosis through photodynamic therapy (PDT). Furthermore, this combination nanomedicine can sensitize PDT and impair glycolysis by downregulating HIF-1α. These results suggest that this stimuli-responsive dendritic-polymer-based nanococktail therapy may provide a promising approach for the treatment of EGFR-TKI resistant NSCLC.

Targeted delivery by pH-responsive mPEG-S-PBLG micelles significantly enhances the anti-tumor efficacy of doxorubicin with reduced cardiotoxicity.

Stimuli-responsive nanotherapeutics hold great promise in precision oncology. In this study, a facile strategy was used to develop a new class of pH-responsive micelles, which contain methoxy polyethylene glycol (mPEG) and poly(carbobenzoxy-l-glutamic acid, BLG) as amphiphilic copolymer, and ß-thiopropionate as acid-labile linkage. The mPEG-S-PBLG copolymer was synthesized through one-step ring-opening polymerization (ROP) and thiol-ene click reaction, and was able to efficiently encapsulate doxorubicin (DOX) to form micelles. The physicochemical characteristics, cellular uptake, tumor targeting, and anti-tumor efficacy of DOX-loaded micelles were investigated. DOX-loaded micelles were stable under physiological conditions and disintegrated under acidic conditions. DOX-loaded micelles can be internalized into cancer cells and release drugs in response to low pH in endosomes/lysosomes, resulting in cell death. Furthermore, the micellar formulation significantly prolonged the blood circulation, reduced the cardiac distribution, and selectively delivered more drugs to tumor tissue. Finally, compared with free DOX, DOX-loaded micelles significantly improved the anti-tumor efficacy and reduced systemic and cardiac toxicity in two different tumor xenograft models. These results suggest that mPEG-S-PBLG micelles have translational potential in the precise delivery of anti-cancer drugs.

Patient-derived non-small cell lung cancer xenograft mirrors complex tumor heterogeneity.

Objective: Patient-derived xenograft (PDX) models have shown great promise in preclinical and translational applications, but their consistency with primary tumors in phenotypic, genetic, and pharmacodynamic heterogeneity has not been well-studied. This study aimed to establish a PDX repository for non-small cell lung cancer (NSCLC) and to further elucidate whether it could preserve the heterogeneity within and between tumors in patients. Methods: A total of 75 surgically resected NSCLC specimens were implanted into immunodeficient NOD/SCID mice. Based on the successful establishment of the NSCLC PDX model, we compared the expressions of vimentin, Ki67, EGFR, and PD-L1 proteins between cancer tissues and PDX models using hematoxylin and eosin staining and immunohistochemical staining. In addition, we detected whole gene expression profiling between primary tumors and PDX generations. We also performed whole exome sequencing (WES) analysis in 17 first generation xenografts to further assess whether PDXs retained the patient heterogeneities. Finally, paclitaxel, cisplatin, doxorubicin, atezolizumab, afatininb, and AZD4547 were used to evaluate the responses of PDX models to the standard-of-care agents. Results: A large collection of serially transplantable PDX models for NSCLC were successfully developed. The histology and pathological immunohistochemistry of PDX xenografts were consistent with the patients' tumor samples. WES and RNA-seq further confirmed that PDX accurately replicated the molecular heterogeneities of primary tumors. Similar to clinical patients, PDX models responded differentially to the standard-of-care treatment, including chemo-, targeted- and immuno-therapeutics. Conclusions: Our established PDX models of NSCLC faithfully reproduced the molecular, histopathological, and therapeutic characteristics, as well as the corresponding tumor heterogeneities, which provides a clinically relevant platform for drug screening, biomarker discovery, and translational research.

pH-Responsive hyperbranched polypeptides based on Schiff bases as drug carriers for reducing toxicity of chemotherapy.

Polymeric micelles have great potential in drug delivery systems because of their multifunctional adjustability, excellent stability, and biocompatibility. To further increase the drug loading efficiency and controlled release ability, a pH-responsive hyperbranched copolymer methoxy poly(ethylene glycol)-b-polyethyleneimine-poly(Nε-Cbz-l-lysine) (MPEG-PEI-PBLL) was synthesized successfully. MPEG-PEI-NH2 was synthesized to initiate the ring-opening polymerization of benzyloxycarbonyl substituted lysine N-carboxyanhydride (Z-lys NCA). The introduction of Schiff bases in the polymer make it possible to respond to the variation of pH values, which cleaved at pH 5.0 while stable at pH 7.4. As the polymer was amphiphilic, MPEG-PEI-PBLL could self-assemble into micelles. Owing to the introduction of PEI, which make the copolymer hyperbranched, the pH-responsive micelles could efficiently encapsulate theranostic agents, such as doxorubicin (DOX) for chemotherapy and NIRF dye DiD for in vivo near-infrared (NIR) imaging. The drug delivery system prolonged the drug circulation time in blood and allowed the drug accumulate effectively at the tumor site. Following the guidance, the DOX was applied in chemotherapy to achieve cancer therapeutic efficiency. All the results demonstrate that the polymer micelles have great potential for cancer theranostics.

Multi-Modal Visualization of Uptake and Distribution of Iron Oxide Nanoparticles in Macrophages, Cancer Cells, and Xenograft Models.

Iron oxide nanoparticles (IONPs) have shown great potential in various biomedical applications. However, information on the interaction between IONPs and biological systems, especially the uptake and distribution of IONPs in cells and tissues, as well as the mechanism of biological action, is relatively limited. In the present study, multi-modal visualization methods, including confocal fluorescence microscopy, transmission electron microscopy, magnetic resonance imaging, and fluorescence optical imaging, were utilized to unveil the uptake and distribution of IONPs in macrophages, cancer cells, and xenograft models. Our results demonstrated that uptake of IONPs in RAW264.7 macrophages and SKOV-3 cancer cells were dose- and cell type-dependent. Cellular uptake of IONPs was an energy-dependent process, and caveolae-mediated endocytosis was the main uptake pathway. All the IONPs were primarily present in endocytic compartments (e.g., endosomes, lysosomes) inside the cells. At 48 hours after intravenous injection of IONPs in SKOV-3 tumor bearing mice, most of the IONPs was distributed in the liver and spleen, with obvious uptake in the tumor, less but significant amount in the kidney and brain. Taken together, multi-modal visualization approaches in our study provide detailed information on the cellular uptake and tissue distribution of IONPs from multiple levels and perspectives.

Size- and cell type-dependent cellular uptake, cytotoxicity and in vivo distribution of gold nanoparticles.

BACKGROUND: Gold nanoparticles (AuNPs) have shown great promise in biomedical applications. However, the interaction of AuNPs with biological systems, its underlying mechanisms and influencing factors need to be further elucidated. PURPOSE: The aim of this study was to systematically investigate the effects of particle size on the uptake and cytotoxicity of AuNPs in normal cells and cancer cells as well as their biological distribution in vivo. RESULTS: Our data demonstrated that the uptake of AuNPs increased in HepG2 cancer cells but decreased in L02 normal cells, with the increase of particle size (5-50 nm). In both cancer cells and normal cells, small (5 nm) AuNPs exhibited greater cytotoxicity than large ones (20 and 50 nm). Interestingly, 5 nm AuNPs induced both apoptosis and necrosis in HepG2 cells through the production of reactive oxygen species (ROS) and the activation of pro-caspase3, whereas it mainly induced necrosis in L02 cells through the overexpression of TLR2 and the release of IL-6 and IL-1a cytokines. Among them, 50 nm AuNPs showed the longest blood circulation and highest distribution in liver and spleen, and the treatment of 5 nm AuNPs  but not 20 nm and 50 nm AuNPs resulted in the increase of neutrophils and slight hepatotoxicity in mice. CONCLUSION: Our results indicate that the particle size of AuNPs and target cell type are critical determinants of cellular uptake, cytotoxicity and underlying mechanisms, and biological distribution in vivo, which deserves careful consideration in the future biomedical applications.

Uptake, distribution, clearance, and toxicity of iron oxide nanoparticles with different sizes and coatings.

Iron oxide nanoparticles (IONPs) have been increasingly used in biomedical applications, but the comprehensive understanding of their interactions with biological systems is relatively limited. In this study, we systematically investigated the in vitro cell uptake, cytotoxicity, in vivo distribution, clearance and toxicity of commercially available and well-characterized IONPs with different sizes and coatings. Polyethylenimine (PEI)-coated IONPs exhibited significantly higher uptake than PEGylated ones in both macrophages and cancer cells, and caused severe cytotoxicity through multiple mechanisms such as ROS production and apoptosis. 10 nm PEGylated IONPs showed higher cellular uptake than 30 nm ones, and were slightly cytotoxic only at high concentrations. Interestingly, PEGylated IONPs but not PEI-coated IONPs were able to induce autophagy, which may play a protective role against the cytotoxicity of IONPs. Biodistribution studies demonstrated that all the IONPs tended to distribute in the liver and spleen, and the biodegradation and clearance of PEGylated IONPs in these tissues were relatively slow (>2 weeks). Among them, 10 nm PEGylated IONPs achieved the highest tumor uptake. No obvious toxicity was found for PEGylated IONPs in BALB/c mice, whereas PEI-coated IONPs exhibited dose-dependent lethal toxicity. Therefore, it is crucial to consider the size and coating properties of IONPs in their applications.

The effect of particle size on the genotoxicity of gold nanoparticles.

Despite the increasing biomedical applications of gold nanoparticles (AuNPs), their toxicological effects need to be thoroughly understood. In the present study, the genotoxic potential of commercially available AuNPs with varying size (5, 20, and 50 nm) were assessed using a battery of in vitro and in vivo genotoxicity assays. In the comet assay, 20 and 50 nm AuNPs did not induce obvious DNA damage in HepG2 cells at the tested concentrations, whereas 5 nm NPs induced a dose-dependent increment in DNA damage after 24-h exposure. Furthermore, 5 nm AuNPs induced cell cycle arrest in G1 phase in response to DNA damage, and promoted the production of reactive oxygen species (ROS). In the chromosomal aberration test, AuNPs exposure did not increase in the frequency of chromosomal aberrations in Chinese hamster lung (CHL) cells. In the standard in vivo micronucleus test, no obvious increase in the frequency of micronucleus formation was found in mice after 4 day exposure of AuNPs. However, when the exposure period was extended to 14 days, 5 nm AuNPs presented significant clastogenic damage, with a dose-dependent increase of micronuclei frequencies. This finding suggests that particle size plays an important role in determining the genotoxicity of AuNPs. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 710-719, 2017.