Renal Clearable Catalytic 2D Au-Porphyrin Coordination Polymer Augmented Photothermal-Gas Synergistic Cancer Therapy.

As a gasotransmitter, carbon monoxide (CO) possesses antitumor activity by reversing the Warburg effect at higher concentrations. The targeted delivery of carbon monoxide-releasing molecules (CORMs) using nanomaterials is an appealing option for CO administration, but how to maintain CO above the threshold concentration in tumor tissue remains a challenge. Herein, a nanozyme-catalyzed cascade reaction is proposed to promote CO release for high-efficacy photothermal therapy (PTT)-combined CO therapy of cancer. A gold-based porphyrinic coordination polymer nanosheet (Au0 -Por) is synthesized to serve as a carrier for CORM. It also possesses excellent glucose oxygenase-like activity owing to ultrasmall zero-valent gold atoms on the nanosheet. The catalytically generated H2 O2 can efficiently catalyze CORM decomposition, which enables in situ generation of sufficient CO for gas therapy. In vivo, the Au0 -Por nanosheets-enhanced photoacoustic imaging (PAI) and fluorescence imaging collectively demonstrate high tumor-targeting efficiency and nanomaterial retention. Proven to have augmented therapeutic efficacy, the nanoplatform can also be easily degraded and excreted through the kidney, indicating good biocompatibility. Thus, the application of rational designed Au0 -Por nanosheet with facile approach and biodegradable property to PAI-guided synergistic gas therapy can provide a strategy for the development of biocompatible and highly effective gaseous nanomedicine.

Monodispersed Lignin Colloidal Spheres with Tailorable Sizes for Bio-Photonic Materials.

Lignin colloidal spheres (LCSs) are promising biomaterials for application in drug storage and delivery, pollutant adsorption, and ultraviolet protection due to their biocompatibility, amphiphilicity, and conjugated structure. However, wide size distribution of LCSs greatly limits their performances, especially in many precise and advanced applications. Herein, the fabrication of monodispersed LCSs with tailorable sizes ranging from the nanoscale to microscale is reported. Lignin raw materials are first fractionated by solvent extraction, and then the lignin fraction is used to fabricate monodispersed LCSs by solvent/antisolvent self-assembly. The underlying mechanism for the formation of monodispersed LCS is primarily ascribed to the improved homogeneity of long-range intermolecular forces, especially the electrostatic forces and hydrophobic forces, between lignin molecules. Moreover, by manipulating the short-range order of LCSs, an innovative application of lignin as bio-photonic materials with tunable structural colorations (e.g., red, green, or blue) is demonstrated. This work not only provides deep insight and an effective strategy to eliminate the serious inhomogeneity of LCSs, but also makes lignin resources have great potential as biodegradable and biocompatible photonic materials in diverse advanced optical application fields such as photonic devices, anti-counterfeiting labels, and structural color pigments.

Biocompatible Inhibitor Based on Chitosan and Amphiphilic Peptide against Mutant Huntingtin Toxicity.

Huntington's disease (HD) is classified as a protein-misfolding disease correlated with the mutant Huntingtin (mHtt) protein with abnormally expanded polyglutamine (polyQ) domains. Because no effective drugs have yet been reported, attempts to develop better therapy to delay the age of onset are in urgent demand. In this study, an amphiphilic peptide consisting of negatively charged hexaglutamic acid and a stretch of decaglutamine (E6 Q10 ) was chemically synthesized as an inhibitor against polyQ and mHtt toxicity. It is found that E6 Q10 selfassembles into spherical vesicles, as shown by means of TEM, cryoelectron microscopy, and dynamic light scattering. Assembled E6 Q10 prevented the polyQ-rich peptide (KKWQ20 AKK) from forming amyloid fibrils. To enable the cell-penetration ability of E6 Q10 , the E6 Q10 ⋅chitosan complex was generated. It is demonstrated that the complex penetrates cells, interferes with the mHtt oligomerization and aggregation process, and prevents mHtt cytotoxicity. By combining positively charged chitosan and amphiphilic peptides with a negatively charge moiety, a new strategy is provided to develop biocompatible and biodegradable inhibitors against mHtt toxicity.

Photonic Lignin with Tunable and Stimuli-Responsive Structural Color.

Due to the growing sustainability and health requirements, structural color materials fabricated with functional natural polymers have attracted increasing attention in advanced optical and biomedical fields. Lignin has many attractive features such as great biocompatibility, ultraviolet resistance, antioxidant property, and thermostability, making it a promising natural resource to be fabricated as functional structural color materials. However, to date, the utilization of lignin as the building block for structural color materials is still a challenge due to its disordered structure. Herein, we present a strategy to transform disordered lignin into ordered "photonic lignin", in which monodisperse lignin colloidal spheres are prepared via solvent/antisolvent self-assembly, and then the periodic structure is constructed by centrifugal effect. The photonic lignin exhibits structural colors that are tunable by modulating the diameter of lignin colloidal spheres. We further demonstrate the application of photonic lignin as a natural polymer-based coating that shows bright, angle-independent, and stimuli-responsive structural colors. Moreover, the cytotoxicity assay indicates the excellent biocompatibility of photonic lignin with human skin, blood vessels, digestive systems, and other tissues, which demonstrates the great potential of photonic lignin in the applications such as implanted/wearable optical devices, advanced cosmetics, and smart food packaging.

Microplastics influence on Hg methylation in diverse paddy soils.

Microplastics are widespread in estuarine, coastal, and deep sea sediments. The influence of microplastics on mercury (Hg) methylation in paddy soils with different characteristics, however, has not been well reported. In this research, we conducted a microcosmic experiment using red soil and alkaline soil with 2%, 7% and 10% polyvinyl chloride microplastics (PVC-MPs). Diffusive gradients in thin film (DGT) were used to test bioavailable Hg2+ and bioavailable methylmercury (MeHg) in soils. Results showed that PVC-MPs could decrease bioavailable MeHg concentrations both in red soil and alkaline soil. We demonstrated that these decreases could be due to three possible mechanisms: (1) PVC-MPs affected DOM composition, which resulted in a difference in combining capacity for bioavailable Hg2+; (2) PVC-MPs decreased MeHg via changing soil properties (including sulfate and dissolved Fe); (3) PVC-MPs affected the abundance of Proteobacteria, Firmicutes, and hgcA gene in soils. Our results emphasized the significance of investigating effects of microplastics on specific contaminants to implement effective environmental remediation strategies in polluted paddy soils.

Radiographic Risk Factors Associated With Adverse Local Tissue Reaction in Head-Neck Taper Corrosion of Primary Metal-on-Polyethylene Total Hip Arthroplasty.

BACKGROUND: Adverse local tissue reactions (ALTRs) in metal-on-polyethylene (MoP) total hip arthroplasty (THA) with head-neck taper corrosion are multifactorial, involving implant and patient factors. This study aimed to identify any potential clinical risk factors associated with failed MoP THA due to head-neck taper corrosion. METHODS: A series of 146 MoP THA patients was investigated: (1) ALTR (n = 42) on metal artifact sequence MRI and (2) non-ALTR (n = 104). Both cohorts were compared regarding femoral neck shaft angle, acetabular implant orientation, component size, femoral head offset, measurement of medial and vertical femoral offsets, and femoral stem alloy. RESULTS: The occurrence of ALTR was associated with increased radiographic femoral stem offset (36.0 ± 7.7 mm versus 40.8 ± 7.3 mm, P = 0.008), increased femoral head offset (0.7 ± 3.4 versus 4.5 ± 3.7, P < 0.001), and the use of Ti-12Mo-6Zr-2Fe alloy stems (P = 0.041). The presence of ALTR was notably associated with higher chromium (2.0 versus 0.5 µg/L) and cobalt (7.4 versus 0.7 µg/L, P < 0.001). DISCUSSION: This study identified increased femoral head and stem offset and the use of Ti-12Mo-6Zr-2Fe alloy stems as risk factors for clinically relevant ALTR due to head-neck taper corrosion in MoP THA patients. This provides evidenced-based practical information for surgeons in identifying "at-risk" symptomatic MoP THA patients with head-neck taper corrosion for systematic risk stratification.

Polyglutamine-Specific Gold Nanoparticle Complex Alleviates Mutant Huntingtin-Induced Toxicity.

Huntington's disease (HD) belongs to protein misfolding disorders associated with polyglutamine (polyQ)-rich mutant huntingtin (mHtt) protein inclusions. Currently, it is indicated that the aggregation of polyQ-rich mHtt participates in neuronal toxicity and dysfunction. Here, we designed and synthesized a polyglutamine-specific gold nanoparticle (AuNP) complex, which specifically targeted mHtt and alleviated its toxicity. The polyglutamine-specific AuNPs were prepared by decorating the surface of AuNPs with an amphiphilic peptide (JLD1) consisting of both polyglutamine-binding sequences and negatively charged sequences. By applying the polyQ aggregation model system, we demonstrated that AuNPs-JLD1 dissociated the fibrillary aggregates from the polyQ peptide and reduced its ß-sheet content in a concentration-dependent manner. By further integrating polyethyleneimine (PEI) onto AuNPs-JLD1, we generated a complex (AuNPs-JLD1-PEI). We showed that this complex could penetrate cells, bind to cytosolic mHtt proteins, dissociate mHtt inclusions, reduce mHtt oligomers, and ameliorate mHtt-induced toxicity. AuNPs-JLD1-PEI was also able to be transported to the brain and improved the functional deterioration in the HD Drosophila larva model. Our results revealed the feasibility of combining AuNPs, JLD1s, and cell-penetrating polymers against mHtt protein aggregation and oligomerization, which hinted on the early therapeutic strategies against HD.

Vaping cartridge heating element compositions and evidence of high temperatures.

BACKGROUND: Identifying the functional materials inside vaping devices can help inform efforts to understand risk. While nicotine E-cigarette components and metals have been characterized in several previous studies, the internal component compositions of tetrahydrocannabinol (THC) cartridge designs are not as well known. The 2019-20 e-cigarette or vaping product use associated lung injury (EVALI) outbreak has been associated with THC devices containing vitamin E acetate (VEA), possibly mediated by chemical reactions with internal cartridge components and high filament temperatures. METHODS: We investigate the composition and internal components of 2019 EVALI patient-associated THC vaping devices compared to other THC and nicotine devices from 2016-19, specifically the metal, ceramic, and polymer components likely to be exposed to heat. To do this, we have disassembled forty-eight components from eight used and unused vaping devices under a microscope and analyzed them using X-ray fluorescence, scanning electron microscopy, and Fourier-transform infrared micro-spectroscopy. CONCLUSIONS: The two THC cartridges used by EVALI patients exhibited evidence of localized high temperatures, including charring of the ceramic heating elements and damaged wire surfaces. The newer THC cartridges possessed more ceramic and polymer insulation than older THC or nicotine devices. The combination of ceramics, metals, and high temperatures in newer THC cartridges is consistent with conditions hypothesized to produce VEA reactions during vaping. Nickel and chromium components were detected in all devices, and others contained copper, lead, tin, gold, silicon-rich rubbers, or fluorinated microplastics. These components have the potential to thermally degrade and volatilize if heated sufficiently. These findings do not imply that harmful exposures would occur under all usage conditions, and are most relevant to harm reduction efforts based on avoiding higher internal temperatures. This study was limited to a small sample of cartridges obtained from investigations. Future work should test more device types and internal temperatures under controlled usage conditions.

Fast self-assembly of microporous silk fibroin membranes on liquid surface.

The air-liquid interface has been used to create micro- and nanostructured polymeric membranes. Here, we employed a novel silk fibroin (SF) solution to create ultrathin membranes effectively on the surface of subphase (30 wt% ammonium sulphate). The SF droplets spread instantaneously at the air-liquid interface driven by the surface tension difference between subphase and SF solutions. Conformational changes for SF molecules from disordered structure to ordered structure occur simultaneously. During the process, SF molecules self-assemble by rearranging hydrophobic and hydrophilic domains to minimize the free energy of the system. Dehydration and denaturation of proteins by high concentration of salt in the subphase promote the polymer solidification. Phase separation results in the porous structure of the SF membrane. Mixing aqueous gelatin with SF solution causes the reduction of pore size, porosity and mechanical properties of the membranes. More aqueous gelatin hinders the polymer solidification within short time. The as-prepared membranes have excellent transparency and cytocompatibility, which have potential for the applications of biotechnology, biomedicine and organ-on-chip.

Head-Neck Taper Corrosion in Metal-on-Polyethylene Total Hip Arthroplasty: Risk Factors, Clinical Evaluation, and Treatment of Adverse Local Tissue Reactions.

Adverse local tissue reaction (ALTR) associated with mechanically assisted crevice corrosion of metal-on-polyethylene (MoP) head-neck modular total hip arthroplasty (THA), similarly observed in the metal-on-metal bearing, is a growing concern in MoP THA patients. Given the complex pathogenesis as well as variable clinical presentation, the diagnosis can be challenging. This article focuses on providing surgeons with an evidence-based update on (1) implant, surgical, and patient risk factors associated with ALTRs; (2) clinical systematic evaluation; and (3) surgical management options for ALTRs in MoP THA patients based on the currently available evidence.