Manganese dioxide decorated kiwi peel powder for efficient removal of lead from aqueous solutions, blood and Traditional Chinese Medicine extracts

For human health and environment safety, it is of great significance to develop novel materials with high effectiveness for removal of lead from not only aqueous solutions but also human body and traditional Chinese medicines. Here, functional kiwi peel composite, manganese dioxide decorated kiwi peel powder (MKPP), is proposed for the removal of Pb2+ effectively. The adsorption of Pb2+ in aqueous solution is a highly selective and endothermic process and kinetically follows a pseudo-second-order model, which can reach equilibrium with the capacity of 192.7 mg/g within 10 min. Comprehensive factors of hydration energy, charge-to-radius ratio and softness of Pb2+ make a stronger affinity between MKPP and Pb2+. The possible adsorption mechanism involves covalent bond, electrostatic force and chelation, etc. MKPP can be efficiently regenerated and reused with high adsorption efficiency after five cycles. Besides, MKPP can remove over 97% of Pb2+ from real water samples. MKPP can also alleviate lead poisoning to a certain extent and make the Pb level of TCM extract meet the safety standard. This work highlights that MKPP is a promising adsorbent for the removal of Pb2+ and provides an efficient strategy for reusing kiwi peel as well as dealing with the problem of Pb pollution.

Fabrication of 2D nanosheet sorbents through metastable emulsion droplets and subsequent two-step grafting polymerization for efficient blood lead removal in vitro

Hemoperfusion is a powerful and yet simple method for lead poisoning treatment, but creation of safe and effective sorbents with excellent selectivity remains a real challenge. To address this, we here construct 2D nanosheet sorbents (BM-SH) through metastable emulsion droplets and subsequent two-step grafting polymerization for efficient blood lead removal in vitro. Metastable emulsion droplets endow typical nanosized sheet-like structure (thickness of 30 nm) and relatively round shape. The consecutive two grafting processes using hydroxyethyl methacrylate (HEMA) and L-cysteine monomer (D-SH) provide BM-SH with a high density of accessible binding sites towards lead ions (Pb²⁺). A high adsorption capacity of 390.5 mg g^-1 and quick capture 97.35 % of Pb²⁺ within initial 10 min are obtained, surpassing most of the reported sorbents for lead removal. Besides, adsorption distribution coefficient (K_d) of BM-SH among four coexisting metal ions achieved 7792 mL g^-1, showing outstanding selectivity toward Pb²⁺. Importantly, a possible adsorption mechanism is recognized as coordination with carboxyl, sulfydryl and imino groups from L-cysteine, and mercapto ligand as the key chelating agent may be the reason for high Pb²⁺ affinity. And what's more, BM-SH displays good hemocompatibility and high efficiency of blood lead removal rate (above 86 % in vitro).

Near-Infrared Light-Driven Multifunctional Tubular Micromotors for Treatment of Atherosclerosis

One of the difficulties in atherosclerosis treatment is that the ablation of inflammatory macrophages, repair of vascular endothelial injury, and anti-tissue proliferation should be considered. However, there are few studies that can solve the abovementioned problems simultaneously. Herein, we present a kind of near-infrared (NIR) light-driven multifunctional mesoporous/macroporous tubular micromotor which can rapidly target the damaged blood vessels and release different drugs. Their motion effect can promote themselves to penetrate into the plaque site, and the generated heat effect caused by NIR irradiation can realize the photothermal ablation of inflammatory macrophages. Furthermore, these micromotors can rapidly release the vascular endothelial growth factor for endothelialization and slowly release paclitaxel for antiproliferation to achieve synergistic treatment of atherosclerosis. In vivo results demonstrated that the micromotors can achieve a good therapeutic effect for atherosclerosis. This kind of micro/nanomotor technology with a complex porous structure for drug loading will bring a more potential treatment platform for the disease.

Magnetic mesoporous silica/ε-polylysine nanomotor-based removers of blood Pb2

The removal of excessive blood lead ions (Pb2+) is very important to human health, but current effective removal technology is still lacking because of the complex existence state of Pb2+ in blood, which can be attributed to the fact that most of the blood Pb2+ is combined with haemoglobin (Hb) located in red blood cells (RBCs). Here, a new type of magnetic mesoporous silica/ε-polylysine nanomotor-based remover (MMS/P NR) with abundant chelation sites was designed, synthesized and used to remove Pb2+ from blood. The magnetic core can make the nanocomposites become nanomotors with autonomous movement under an external variable magnetic field, which can effectively improve the contact probability between the MMS/P NRs and Pb2+-contaminated Hb in RBCs. The amino rich ε-polylysine (ε-PL) was used as the co-template of mesoporous silica. Mesoporous channels can provide a confinement effect for Pb2+-contaminated Hb to stabilize the captured blood Pb2+. The movement behavior of the MMS/P NRs in and out of RBCs and the capture mechanism of Pb2+ in the blood were studied. The results indicate that the MMS/P NRs we propose have good blood compatibility, low cytotoxicity, magnetic properties, autonomous movement ability and recyclability under the condition of an external magnetic field. Moreover, compared with the experimental conditions without an external variable magnetic field (0.01485 mg g-1), the MMS/P NRs show a higher blood Pb2+ removal ability under the condition of an external variable magnetic field (0.05525 mg g-1). The design strategy of this remover based on nanomotor technology has great potential in the future medical treatment of heavy metal poisoning.

Unified Probability Distribution and Dynamics of Lead Contents in Human Erythrocytes Revealed by Single-Cell Analysis

Understanding the presence and dynamics of chemical pollutants in individual cells is fundamentally important for their trafficking, fate, and toxicity in humans. The presence of molecular components (i.e., proteins and mRNA) in individual cells of higher organisms is considered a stochastic event. The characteristics of chemical pollutants, as extrinsic compounds, in subpopulation of human cells on single-cell basis have not been explored yet. Here, we demonstrated the lead (Pb) content in individual mature erythrocytes (m-erythrocytes) of Pb-intoxicated patients, and healthy subjects exhibited a unified pattern in probability distribution (gamma distribution) and dynamics, despite being highly heterogeneous. The Pb content in individual m-erythrocytes decreased with the lifetime of m-erythrocytes. Meanwhile, the distribution and dynamics were found to be highly related to the Pb content in m-erythrocytes and was independent of patients and their status. This is the first study to analyze the distribution pattern of chemical pollutants at a single-cell level in higher organisms. This study sheds light on the molecular mechanism of Pb trafficking and fate in humans and the search for an efficient strategy to improve Pb excretion during Pb treatment.

Nanomotor-based adsorbent for blood Lead(II) removal in vitro and in pig models

Blood lead (Pb(II)) removal is very important but challenging. The main difficulty of blood Pb(II) removal currently lies in the fact that blood Pb(II) is mainly complexed with hemoglobin (Hb) inside the red blood cells (RBCs). Traditional blood Pb(II) removers are mostly passive particles that do not have the motion ability, thus the efficiency of the contact between the adsorbent and the Pb(II)-contaminated Hb is relatively low. Herein, a kind of magnetic nanomotor adsorbent with movement ability under alternating magnetic field based on Fe₃O₄ nanoparticle modified with meso-2, 3-dimercaptosuccinic acid (DMSA) was prepared and a blood Pb(II) removal strategy was further proposed. During the removal process, the nanomotor adsorbent can enter the RBCs, then the contact probability between the nanomotor adsorbent and the Pb(II)-contaminated Hb can be increased by the active movement of nanomotor. Through the strong coordination of functional groups in DMSA, the nanomotor adsorbent can adsorb Pb(II), and finally be separated from blood by permanent magnetic field. The in vivo extracorporeal blood circulation experiment verifies the ability of the adsorbent to remove blood Pb(II) in pig models, which may provide innovative ideas for blood heavy metal removal in the future.

Erythrocyte Membrane-Wrapped Magnetic Nanotherapeutic Agents for Reduction and Removal of Blood Cr(VI)

The hazard of hexavalent chromium (Cr(VI)) from environmental pollution and medical implanted metal has been recognized widely. However, removal of trace amount of Cr(VI) in the blood circumstance faces tremendous difficulties for that most of Cr(VI) located in erythrocytes, thus there is almost no literature to report the removal of Cr(VI) in blood. Herein, a removal strategy, named as reduction-adsorption-separation, is proposed to realize the removal of Cr(VI) in blood. First, magnetic core-shell mesoporous nanocomposite is fabricated by using Fe₃O₄ nanoparticles as magnetic core and mesoporous silica (MS) as shell, hyperbranched polyamide (HPA) as mesoporous channel modifier and ascorbic acid (ASC) as the reductant drug loaded in the mesoporous channels, which is also denoted as Fe/MS/HPA/ASC. Then, on the basis of the bionic idea, the erythrocyte membrane (EM)-wrapped Fe/MS/HPA/ASC to protect ASC from deactivation is obtained and named as the therapeutic agent (Fe/MS/HPA/ASC@EM). During removal process, the therapeutic agent can enter in erythrocytes to use ASC to reduce Cr(VI) to Cr(III) and HPA in mesoporous channels to adsorb Cr(III) and can then be recollected from blood by magnetic separation. Finally, an animal model of blood Cr(VI) poisoning is constructed and used to test the removal ability of Cr(VI) from pig blood in vivo, verifying the effectiveness of this blood Cr(VI) removal strategy, providing a possible way to design more efficient and biosafe therapeutic agents for blood purification.

Coronary Stents Decorated by Heparin/NONOate Nanoparticles for Anticoagulant and Endothelialized Effects

In the treatment of coronary artery disease (CAD), the use of stent implantation often leads to clinical complications such as restenosis, delayed endothelial healing, and thrombosis. Here, we develop a double drug sustained-release coating for the stent surface by grafting heparin/NONOate nanoparticles (Hep/NONOates). The Hep/NONOates and surface modification of the stent were characterized by X-ray photoelectron spectroscopy, attenuated total reflection Fourier-transform infrared spectroscopy, static water contact angle, and scanning electron microscopy (SEM), and the release behaviors of the anticoagulant, heparin (Hep) and the bioactive molecule, nitric oxide (NO) were studied. Furthermore, the blood compatibility and cytotoxicity of the modified stent were evaluated by whole blood adhesion and platelet adhesion tests, hemolysis assay, morphological changes of red blood cells, plasma recalcification time assay, in vitro coagulation time tests, and MTT assay. Finally, the results of a rabbit carotid artery stent implantation experiment showed that the double drug sustained-release coating for the stent can accelerate regeneration of endothelial cells and keep good anticoagulant activity. This study can provide new design ideas based on nanotechnology for improving the safety and effectiveness of drug-eluting stents.

A zipped-up tunable metal coordinated cationic polymer for nanomedicine

Incorporating metal elements into polymers is a feasible means to fabricate new materials with multiple functionalities. In this work, a metal coordinated cationic polymer (MCCP) was developed. Ferric ions were incorporated into the polyethyleneimine-β-cyclodextrin (PC) polymer chain via coordination to produce a zipped-up polymer with a micro-ordered and macro-disordered topological structure. By varying the metal concentration, a tunable superstructure could be formed on the nano-templates via the "zipping" effect. In addition, the physicochemical properties of the assembly of MCCPs and nucleic acids were tailored by tuning the composition of the metal ions and polymers. The loading efficiency of Rhodamine-B by MCCPs was enhanced. The in vitro and in vivo results showed that the hybrid materials could be adjusted to deliver nucleic acids or small molecules with good performance and acquired the capacity of generating reactive oxygen species in tumor cells. Thus, the tunable and multifunctional MCCP system has great potential in nanomedicine and biomaterial science.

A dual-responsive biosensor for blood lead detection

Simple and accurate detection of trace heavy metals in blood is very important. A novel dual-responsive electrochemical/fluorescent biosensor based on magnetic hyperbranched polyamide with heparin modification (MHPAM-H) for blood lead detection has been successfully developed. Upon conjugated with blood lead ions, dual-biosensor could not only display electrochemical signal but also fluorescence signal owing to the enriched amino groups, cavity structure, and good fluorescence properties of HPAM. Blood biocompatibility, construction of the dual-responsive biosensor, electrochemical/fluorescent detection of lead ions in water phase and blood condition, selectivity and stability of the dual-responsive biosensor were investigated in detail. The proposed dual-responsive biosensor displays good linear relationship (1.5 pM- 4.8 × 10³ pM for electrochemical detection and 0.5 pM-4.8 × 10³ pM for fluorescent detection) with low detection limit (4.4 pM for electrochemical detection and 1.0 pM for fluorescent detection) for blood lead, providing potential application for blood lead detection in the future.