Surface Functionalization Of Nanoparticles Research Articles

Recycling of Surface-Functionalized Nanoparticles—A Short Review

The present manuscript provides a comprehensive overview and partial analysis of both advanced and innovative recycling techniques for functionalized nanoparticles. Such methods are sieving techniques including filtration in different forms (e.g., ultrafiltration, diafiltration), centrifugation, and chromatography. Further microfluidics, solvent extraction, and evaporation as well as magnetic and electric field-assisted methods are presented followed by more conventional methods such as precipitation, coagulation, and ζ-potential changes. To facilitate future progress in nanotechnology recycling, it is necessary to provide improved and innovative production techniques across the whole life cycle of nanotechnology. This is analogous to any other methodology that is conceptualized during the initial phases. Furthermore, a diverse array of preparation methods for functionalized nanoparticles may be developed and implemented using various approaches depending on the evident use of the material. Further, the investigation of waste products containing nanoparticles is not yet possible to achieve an in-depth knowledge of this subject. Moreover, advanced technologies have the capacity to enable a more substantial future implementation of NM recycling for commercial use.

Targeted NAD+ repletion via biomimetic nanoparticle enables simultaneous management of intimal hyperplasia and accelerated re-endothelialization: A proof-of-concept study toward next-generation of endothelium-protective, anti-restenotic therapy

Endovascular interventions often fail due to restenosis, primarily caused by smooth muscle cell (SMC) proliferation, leading to intimal hyperplasia (IH). Current strategies to prevent restenosis are far from perfect and impose significant collateral damage on the fragile endothelial cell (EC), causing profound thrombotic risks. Nicotinamide adenine dinucleotide (NAD+) is a co-enzyme and signaling substrate implicated in redox and metabolic homeostasis, with a pleiotropic role in protecting against cardiovascular diseases. However, a functional link between NAD+ repletion and the delicate duo of IH and EC regeneration has yet to be established. NAD+ repletion has been historically challenging due to its poor cellular uptake and low bioavailability. We have recently invented the first nanocarrier that enables direct intracellular delivery of NAD+ in vivo. Combining the merits of this prototypic NAD + -loaded calcium phosphate (CaP) nanoparticle (NP) and biomimetic surface functionalization, we created a biomimetic P-NAD + -NP with platelet membrane coating, which enabled an injectable modality that targets IH with excellent biocompatibility. Using human cell primary culture, we demonstrated the benefits of NP-assisted NAD+ repletion in selectively inhibiting the excessive proliferation of aortic SMC, while differentially protecting aortic EC from apoptosis. Moreover, in a rat balloon angioplasty model, a single-dose treatment with intravenously injected P-NAD + -NP immediately post angioplasty not only mitigated IH, but also accelerated the regeneration of EC (re-endothelialization) in vivo in comparison to control groups (i.e., saline, free NAD+ solution, empty CaP-NP). Collectively, our current study provides proof-of-concept evidence supporting the role of targeted NAD+ repletion nanotherapy in managing restenosis and improving reendothelialization.

Deciphering the Role of Inorganic Nanoparticles' Surface Functionalization on Biohybrid Microbial Photoelectrodes.

Shedding light on the interaction between inorganic nanoparticles (NPs) and living microorganisms is at the basis of the development of biohybrid technologies with improved performance. Au NPs have been shown to be able to improve the extracellular electron transfer (EET) in intact bacterial cells interfaced with an electrode; however, detailed information on the role of NP-surface properties in their interaction with bacterial membranes is still lacking. Herein, we unveil how the surface functionalization of Au NPs influences their interaction with photosynthetic bacteria, focusing on cell morphology, growth kinetics, NPs localization, and electrocatalytic performance. We show that functionalization of Au NPs with cysteine in the zwitterionic form results in a uniform NPs distribution in purple bacteria, specifically locating the NPs within the outer-membrane/periplasmic space of bacterial cells. These biohybrid cells, when coupled with an electrode, exhibit enhanced EET and increased (photo)current generation, paving the way for the future development of rationally designed biohybrid electrochemical systems.

Surface Functionalization of Gold Nanoparticles Using Alkyne Derivatives: Applications in Chemical Sensing.

Colloidal gold nanoparticles (AuNPs) are important nanomaterials for chemical sensing and therapeutics. For their application, it is vital to develop a reliable and robust surface functionalization method that can be applied to diverse functional molecules and offer better stability under harsh biological conditions. Currently, thiol (SH) is the most commonly used functional group for forming stable covalent bonds with AuNPs. However, thiolated molecules typically require complicated preparation procedures, are susceptible to oxidation, and are not compatible with many electrophiles and reducing groups. In this study, we report that surface functionalization of AuNPs can be achieved using alkyne derivatives, which exhibit several advantages over classical thiolation and peptide-bond methods, including straightforward preparation of alkyne derivatives, rapid and simple conjugation in buffers and complex media, higher conjugation efficiency, long-term stability, and resistance to decomposition under harsh conditions. Several alkynylated biotin and fluorescein derivatives are prepared, and the alkynylated-AuNPs are characterized using a lateral flow assay, gel electrophoresis, and spectroscopy techniques to investigate the conjugation efficiencies, size distributions, protein interaction properties, and binding mode of the Au-alkyne bond. We also demonstrate that alkynylated-AuNPs can be used for the sensitive detection of hydrogen peroxide and streptavidin proteins.

Amine-Terminated Silver Nanoparticles Exhibit Potential for Selective Targeting of Triple-Negative Breast Cancer

Silver nanoparticles (AgNPs) demonstrate potential in treating aggressive cancers such as triple-negative breast cancer (TNBC) in preclinical models. To further the development of AgNP-based therapeutics for clinical use, it is essential to clearly define the specific physicochemical characteristics of the nanoparticles and connect these properties to biological outcomes. This study addresses this knowledge gap through detailed investigations into the structural and surface functional relationships, exploring the mechanisms, safety, and efficacy of AgNPs in targeting TNBC. The surface functionality of nanoparticles is crucial not only for their internalization into cancer cells but also for enhancing their toxicity toward tumor cells. Although the nanoparticles internalized into cancer cells, they failed to exhibit their full toxicity against the cancer. Herein we report a solvent-assisted synthesis amine, mercaptohexanol and bifunctional silver nanoparticles and performing comparative study to understand their selectivity and toxicity toward TNBC cells. The nanoparticles are fully characterized by UV–visible absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and dynamic light scattering measurement (DLS). The synthesis method achieves an extremely high yield and surface coating ratio of synthesized colloidal AgNPs. Our findings reveal that the amine-capped AgNPs exhibit significant selective toxicity against TNBC cell lines MCF7 and MDA-MB-231 at a concentration of 40 µg/mL without affecting normal breast cell lines MCF10A. This study underscores the potential of functionalized AgNPs in developing safe and targeted therapeutic approaches for treating aggressive cancers like TNBC, laying the groundwork for future clinical advancements.

Stabilization and Surface Functionalization of Palladium Disulfide Nanoparticles with Acetylene Derivatives.

Metal chalcogenide nanoparticles have been attracting extensive attention in diverse fields. Traditionally these nanoparticles are stabilized by organic ligands such as thiols and amines involving nonconjugated core-ligand interfacial interactions. In the present study, a facile wet-chemistry method is described for the synthesis of palladium disulfide (PdS2) nanoparticles capped with acetylene derivatives. Spectroscopic and electrochemical measurements suggest that conjugated Pd-C≡ linkages are formed at the core-ligand interface and facilitate electronic coupling and hence manipulation of the nanoparticle optical and electronic properties. The unique interfacial linkages also allow further functionalization of the nanoparticles by metathesis reaction with olefin derivatives, as manifested in the reaction with vinylferrocene. This research opens new avenues for the structural engineering and functionalization of metal chalcogenide nanoparticles.

Stabilizing Bicontinuous Emulsions with Sub-Micrometer Domains Solely by Nanoparticles.

Nanoparticle-stabilized, bicontinuous interfacially jammed emulsion gels (bijels) find potential applications as battery, separation membrane, and chemical reactor materials. Decreasing the liquid domain sizes of bijels to sub-micrometer dimensions requires surfactants, complicating bijel synthesis and postprocessing into functional nanomaterials. This work introduces surfactant-free bijels with sub-micrometer domains, solely stabilized by nanoparticles. To this end, the covalent surface functionalization of silica nanoparticles is characterized by thermogravimetric analysis, mass spectrometry, Fourier-transform infrared spectroscopy, and contact angle measurements. Bijels are generated with the functionalized nanoparticles via solvent transfer induced phase separation (STrIPS), enabling the optimization of nanoparticle functionalization and surface ionization. Nanoparticles of intermediate functionalization and controlled negative surface charge stabilize bijels with sub-micrometer liquid domains. This remarkable control over bijel synthesis provides urgently needed progress to facilitate the widespread implementation of bijels as nanomaterials in research and applications.

Microbubble-enhanced cold plasma activation (MB-CPA) for surface functionalization of polymer nanoparticles from nanoprecipitation

Cold plasma activation has been considered as a green and effective technological approach for functionalization of solid surfaces. In the current study, we introduce a versatile technique known as microbubble-enhanced cold plasma activation (MB-CPA) for surface modification of polymer plates and nanoparticles in flowing liquid phase. Corona plasma is generated at the inlet of a venturi tube, thereby creating a highly excited state in the air. Reactive nitrogen and oxygen species (RNOS) are transferred from the gas phase to the suspension flow in the form of plasma microbubbles. Two types of polymer-based nanoparticles in the suspension, namely polymethyl methacrylate (PMMA) of 16–154 nm and polycaprolactone (PCL) of 30–225 nm, are synthesized using nano-precipitation method. Through the degradation of model compounds, the polar organic solvent, acetone and ethanol, is found to promote or suppress the production of active species. In addition, the efficiency of the MB-CPA treatment depends on the solvent composition, making this technology a controllable and efficient strategy for the surface modification of nanoparticles. The findings indicate that plasma activation effectively reduces the negative surface zeta-potentials and induces aggregation and separation in the suspensions. The infrared spectra of the treated nanoparticles reveal that plasma activation leads to the formation of NH and CN bonds situated on the surface of PMMA. Our work demonstrates that organic-solvent involved MB-CPA emerges as a promising method for the surface modification of nanoparticles in the flow condition.

Symmetry-Breaking of Nanoparticle Surface Function Via Conformal DNA Design.

Asymmetric surface functionalization of complex nanoparticles to control their directional self-assembly remains a considerable challenge. Here, we demonstrated a conformal DNA design strategy for flexible remodeling of the surface of complex nanoparticles, taking Au nanobipyramids (AuNBPs) as a model. We sheathed one or both tips of AuNBPs into conformal DNA origami with an exceptionally accurate orientation control. Such asymmetrically and symmetrically distributed surface patches possess regioselective, sequence, and site-specific DNA binding capabilities. As a result, we realized a series of prototypical multicomponent "colloidal molecules" made of AuNBPs and Au nanospheres (AuNSs) with defined directionality and number of "bonding valence" as well as 1D and 3D hierarchical assemblies, e.g., inverse core-satellites of AuNBPs and AuNSs, side-by-side and tip-to-tip linear assemblies of AuNBPs, and 3D helical superstructures of AuNBPs with tunable twists. These findings inspire new opportunities for nanoparticle surface engineering and the high-order self-assembly of nanoarchitectures with higher complexity and broadened functionalities.

Effects of Different Surface Functionalizations of Silica Nanoparticles on Mesenchymal Stem Cells.

Physicochemical properties of nanoparticles, such as particle size, surface charge, and particle shape, have a significant impact on cell activities. However, the effects of surface functionalization of nanoparticles with small chemical groups on stem cell behavior and function remain understudied. Herein, we incorporated different chemical functional groups (amino, DETA, hydroxyl, phosphate, and sulfonate with charges of +9.5, + 21.7, -14.1, -25.6, and -37.7, respectively) to the surface of inorganic silica nanoparticles. To trace their effects on mesenchymal stem cells (MSCs) of rat bone marrow, these functionalized silica nanoparticles were used to encapsulate Rhodamine B fluorophore dye. We found that surface functionalization with positively charged and short-chain chemical groups facilitates cell internalization and retention of nanoparticles in MSCs. The endocytic pathway differed among functionalized nanoparticles when tested with ion-channel inhibitors. Negatively charged nanoparticles mainly use lysosomal exocytosis to exit cells, while positively charged nanoparticles can undergo endosomal escape to avoid scavenging. The cytotoxic profiles of these functionalized silica nanoparticles are still within acceptable limits and tolerable. They exerted subtle effects on the actin cytoskeleton and migration ability. Last, phosphate-functionalized nanoparticles upregulate osteogenesis-related genes and induce osteoblast-like morphology, implying that it can direct MSCs lineage specification for bone tissue engineering. Our study provides insights into the rational design of biomaterials for effective drug delivery and regenerative medicine.

Site-selective antibody-lipid conjugates for surface functionalization of red blood cells and targeted drug delivery

Displaying antibodies on carrier surfaces facilitates precise targeting and delivery of drugs to diseased cells. Here, we report the synthesis of antibody-lipid conjugates (ALCs) through site-selective acetylation of Lys 248 in human Immunoglobulin G (IgG) and the development of antibody-functionalized red blood cells (immunoRBC) for targeted drug delivery. ImmunoRBC with the HER2-selective antibody trastuzumab displayed on the surface (called Tras-RBC) was constructed following a three-step procedure. First, a peptide-guided, proximity-induced reaction transferred an azidoacetyl group to the ε-amino group of Lys 248 in the Fc domain. Second, the azide-modified IgG was subsequently conjugated with dibenzocyclooctyne (DBCO)-functionalized lipids via strain-promoted azide–alkyne cycloaddition (SPAAC) to result in ALCs. Third, the lipid portion of ALCs was then inserted into the cell membranes, and IgGs were displayed on red blood cells (RBCs) to construct immunoRBCs. We then loaded Tras-RBC with a photosensitizer (PS), Zinc phthalocyanine (ZnPc), to selectively target HER2-overexpressing cells, release ZnPc into cancer cells following photolysis, and induce photodynamic cytotoxicity in the cancer cells. This work showcases assembling immunoRBCs following site-selective lipid conjugation on therapeutic antibodies and the targeted introduction of PS into cancer cells. This method could apply to the surface functionalization of other membrane-bound vesicles or lipid nanoparticles for antibody-directed drug delivery.

Zr4+-mercaptosuccinate MOF for the uptake and recovery of gold nanoparticles and gold ions under batch and continuous flow conditions

The increasing use of nanomaterials in commercial products has raised concerns regarding their potential effects on water quality and living organisms. So far, most sorbents available for removing nanosized inorganic pollutants from water rely on electrostatic interactions or entrapment in the sorbent pores. However, this limits their applicability in real wastewater samples containing nanomaterials with variable surface properties and sizes, along with high concentrations of competitive species such as inorganic salts and organics. Little attention has also been paid to the recovery of nanoparticles after sorption. In this work, a Zr4+-mercaptosuccinate metal organic framework (MOF) with free thiol groups was investigated as a sorbent for the removal of Au nanoparticles and Au3+ ions from water. Sorption occurs on the surface of the MOF via the formation of strong metal-thiolate chemical bonds enabling the fast uptake of noble metal nanoparticles and noble metal ions from water (within <1 h). The maximum sorption capacity was found to depend on the size of the Au nanoparticles and ranged from 8 to 41.5 mg/g. The surface functionalization of nanoparticles did not influence sorption performance, which was also maintained in natural waters of variable matrix complexity. The material was also efficient in fixed bed columns with an estimated maximum Au sorption capacity of approximately 7 mg/g, which is significantly higher than the environmental concentrations of Au nanoparticles and adequate for their removal from industrial wastewater. Importantly, the sorbed nanoparticles could be quantitatively recovered (>90 %), at the expense of material degradation, enabling their potential reuse.

Tailoring ZnO nanoparticles for biomedical applications: Surface functionalization of ZnO nanoparticles with 2-oxo-2H-chromene-3-carboxylic acid coupled beta-cyclodextrin for enhanced antimicrobial and anticancer effect

Nanomedicine has newly emerged as a superior alternative for the treatment of numerous life-threatening illnesses. Zinc oxide nanomaterials have attracted a lot of attention in this decade because of their enormous potential in a wide range of biomedical applications. This work describes the surface functionalization of zinc oxide nanoparticles (ZnO NPs) with 2-oxo-2H-chromene-3-carboxylic acid (3-CCA) coupled beta-cyclodextrin (β-CD) to create a biocompatible system (ZnO-β-CD-3-CCA) and the evaluation of its antimicrobial and anticancer properties. Different characterization techniques, such as X-ray powder diffraction, UV–Vis spectroscopy, FTIR, transmission, and scanning electron microscopy, were used to characterize the biocompatible system. The antimicrobial properties of the synthesized ZnO NPs and the surface functionalized ZnO-β-CD-3-CCA system were evaluated using the disc diffusion method. Modification with functionalized β-CD systems increased the bacteriostatic effect of ZnO nanoparticles against various microbes. In vitro cytotoxicity of ZnO NPs and surface functionalized ZnO-β-CD-3-CCA system was evaluated against two distinct cancer cell lines: MCF-7, Hep G2, and normal rat spleen cells employing MTT assay, and the results highlight that the selective cytotoxicity of the surface functionalized ZnO-β-CD-3-CCA system against the human breast cancer (MCF-7) and human liver cancer (Hep G2) cell lines were superior to that of ZnO NPs. Also, the developed systems were less toxic to normal rat spleen cells. This work is significant because it could result in next-generation nanoparticle-based cancer treatments that are more successful.

A Comprehensive Study on Folate-Targeted Mesoporous Silica Nanoparticles Loaded with 5-Fluorouracil for the Enhanced Treatment of Gynecological Cancers.

Gynecological cancers are a significant public health concern, accounting for 40% of all cancer incidence and 30% of deaths in women. 5-Fluorouracil (5-FU) can be used with chemotherapy to improve treatment in advanced-stage gynecological cancer. Mesoporous silica nanoparticles (MSNs) can improve drug effectiveness and reduce toxicity. Folic acid can target folate receptors in epithelial malignancies like ovarian and cervical cancer. The mixture of MSN-NH2 was synthesized by dissolving N-lauroylsarcosine sodium in a water-ethanol mixture, adding APTES and TEOS, and heating at 80 °C for 18 h, before being fully characterized. The drug is loaded into a 5-FU solution and functionalized with folate. The drug release mechanism, as well as ex vivo intestinal permeation from MSN-NH2 formulations, was tested. The cell viability study of the nanoparticles was evaluated in various cancer cell lines, and the cellular uptake was measured indirectly using HPLC. The study analyzed the amine content, propylamine loading, and drug loading capacity of MSN-NH2 nanoparticles. It found that the loading of propylamine was around 0.733 mmol/g, and the surface density was 0.81 molecules/nm. The study also showed that the surface decoration of MSN-NH2 with folic acid was successfully achieved. The release rate of 5-FU from MSN-NH2 was slow and controlled, with a slower rate at pH 5.5. The study found that the amin surface functionalization of MSN-NH2 nanoparticles can reduce potential toxicity in ovarian and cervical cancer cells. Based on the results, the encapsulation of 5-FU and functionalization of MSN-NH2 with folic acid can serve as potential carriers for 5-FU in treating gynecological cancer.

Refining shape and size of silver nanoparticles using ion irradiation for enhanced and homogeneous SERS activity

We present green synthesis of silver nanoparticles in water using unirradiated and Ag15+\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{15+}$$\\end{document} ion irradiated phytoextracts of Bergenia Ciliata leaf, Eupatorium adenophorum leaf, Rhododendron arboreum leaf and flower. The use of different plant extracts and their subsequent ion irradiation allow for successful refinement of nanoparticle size and morphology. Due to changes in reducing and capping agents the nanoparticle surface functionalization also varies which not only controls the morphology but also allows for surface oxidation and aggregation processes. In this work, we have synthesized silver nanoparticles which exhibit sizes in the range from 13 to 24 nm and having shapes like spherical, quasispherical, trigonal, hexagonal, cylindrical, dendritic assemblies, and porous nanoparticles. Owing to changes in the size and shape of the nanoparticles, their direct bandgap (2.05 eV - 2.48 eV) and local surface plasmon resonance (420 nm - 490 nm) could also be tuned. These nanoparticles are examined as SERS substrates, where their enhancement factors, limit of detection for methylene blue, and SERS substrate homogeneity have been tested. It has been observed the nanoparticles synthesized using unirradiated plant extracts present an enhancement factor of 106\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^6$$\\end{document} with a limit of detection 10-8\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-8}$$\\end{document} M. Whereas nanoparticles with refined morphology and shapes upon irradiation present high enhancement factors of >107\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^7$$\\end{document} and detection limit down to 10-9\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-9}$$\\end{document} M. In addition, uniformity in Raman spectra over the SERS substrates has been obtained for selected Ag NPs substrates synthesized using irradiated extracts with minimum relative standard deviation in enhancement factor < 12%.

Supramolecular Heterodimer Peptides Assembly for Nanoparticles Functionalization.

Nanoparticle (NP) surface functionalization with proteins, including monoclonal antibodies (mAbs), mAb fragments, and various peptides, has emerged as a promising strategy to enhance tumor targeting specificity and immune cell interaction. However, these methods often rely on complex chemistry and suffer from batch-dependent outcomes, primarily due to limited control over the protein orientation and quantity on NP surfaces. To address these challenges, a novel approach based on the supramolecular assembly of two peptides is presented to create a heterotetramer displaying VHHs on NP surfaces. This approach effectively targets both tumor-associated antigens (TAAs) and immune cell-associated antigens. In vitro experiments showcase its versatility, as various NP types are biofunctionalized, including liposomes, PLGA NPs, and ultrasmall silica-based NPs, and the VHHs targeting of known TAAs (HER2 for breast cancer, CD38 for multiple myeloma), and an immune cell antigen (NKG2D for natural killer (NK) cells) is evaluated. In in vivo studies using a HER2+ breast cancer mouse model, the approach demonstrates enhanced tumor uptake, retention, and penetration compared to the behavior of nontargeted analogs, affirming its potential for diverse applications.

Ultrasound assisted biogenic synthesis of Palladium nanoparticles using Cocculus hirsutus leaf extract: Antimicrobial, anti-inflammatory and catalytic activities

We have synthesized palladium nanoparticles (PdNPs) from aqueous leaf extract of Cocculus hirsutus (CH) by ultra-sonication in an easy, non-toxic, and eco-friendly manner. PdNPs synthesized were analyzed using UV–vis, FT-IR, powder XRD, TEM, and DLS instruments. From UV–vis spectra, the Surface Plasmon Resonance (SPR) signal indicated that the formation of PdNPs. The synthesized PdNPs shows spherical shape, crystalline and polydispersibility nature with a mean particle size of 10±3 nm was observed from XRD and TEM. FTIR analysis reveals the active role of phenolic constituents from CH leaf extract in reduction and surface functionalization of nanoparticles. The stability of the PdNPs was assessed by devious the Zeta potential analysis. The as-prepared PdNPs showed antibacterial efficacy (maximum zone of inhibition is 11.20 mm for S. typhimurium) and antifungal efficacy (maximum zone of inhibition is 32.80 mm for C. albicans) against disease causing human pathogens, strong anti-inflammatory activity for BSA denaturation and blistering catalytic activity against 4-NP reduction up to 5 cycles (6 min; 100 % reduction, rate constant is 0.532 min−1). The potency of the anti-inflammatory activity was found to be 90 % using PdNPs against the standard drug Diclofenac sodium (90 %) for 500 µg/mL. The above mentioned activities were used to evaluate the effectiveness of the PdNPs in treating bacterial, inflammation related conditions and also as an effective catalyst in wastewater treatment.

Leveraging Tunable Nanoparticle Surface Functionalization to Alter Cellular Migration.

Gold nanoparticles (AuNPs) are a promising platform for biomedical applications including therapeutics, imaging, and drug delivery. While much of the literature surrounding the introduction of AuNPs into cellular systems focuses on uptake and cytotoxicity, less is understood about how AuNPs can indirectly affect cells via interactions with the extracellular environment. Previous work has shown that the monocytic cell line THP-1's ability to undergo chemotaxis in response to a gradient of monocyte chemoattractant protein 1 (MCP-1) was compromised by extracellular polysulfonated AuNPs, presumably by binding to MCP-1 with some preference over other proteins in the media. The hypothesis to be explored in this work is that the degree of sulfonation of the surface would therefore be correlated with the ability of AuNPs to interrupt chemotaxis. Highly sulfonated poly(styrenesulfonate)-coated AuNPs caused strong inhibition of THP-1 chemotaxis; by reducing the degree of sulfonation on the AuNP surface with copolymers [poly(styrenesulfonate-co-maleate) of different compositions], it was found that medium and low sulfonation levels caused weak to no inhibition, respectively. Small, rigid molecular sulfonate surfaces were relatively ineffective at chemotaxis inhibition. Unusually, free poly(styrenesulfonate) caused a dose-dependent reversal of THP-1 cell migration: at low concentrations, free poly(styrenesulfonate) significantly inhibited MCP-1-induced chemotaxis. However, at high concentrations, free poly(styrenesulfonate) acted as a chemorepellent, causing a reversal in the cell migration direction.

Facile fabrication of Ti4+-immobilized magnetic nanoparticles by phase-transitioned lysozyme nanofilms for enrichment of phosphopeptides.

In this study, titanium (IV)-immobilized magnetic nanoparticles (Ti4+-PTL-MNPs) were firstly synthesized via a one-step aqueous self-assembly of lysozyme nanofilms for efficient phosphopeptide enrichment. Under physiological conditions, lysozymes readily self-organized into phase-transitioned lysozyme (PTL) nanofilms on Fe3O4@SiO2 and Fe3O4@C MNP surfaces with abundant functional groups, including -NH2, -COOH, -OH, and -SH, which can be used as multiple linkers to efficiently chelate Ti4+. The obtained Ti4+-PTL-MNPs possessed high sensitivity of 0.01 fmol μL-1 and remarkable selectivity even at a mass ratio of β-casein to BSA as low as 1:400 for phosphopeptide enrichment. Furthermore, the synthesized Ti4+-PTL-MNPs can also selectively identify low-abundance phosphopeptides from extremely complicated human serum samples and their rapid separation, good reproducibility, and excellent recovery were also proven. This one-step self-assembly of PTL nanofilms facilitated the facile and efficient surface functionalization of various nanoparticles for proteomes/peptidomes.

Niosomes modified with a novel pH-responsive coating (mPEG-OA) enhance the antibacterial and anti-biofilm activity of vancomycin against methicillin-resistant Staphylococcus aureus

Surface functionalization of nanoparticles has shown potential in enhancing the efficacy of antibiotic-loaded nanosystems against drug-resistant bacteria. The objective of this study was to synthesize and characterize an acid-cleavable pH-responsive polymer from methoxy polyethylene glycol and oleylamine (mPEG-OA) to surface modify vancomycin (VCM)-loaded niosomes and to evaluate their antibacterial and anti-biofilm effectiveness against methicillin-resistant Staphylococcus aureus (MRSA). The novel mPEG-OA-coated niosomes were biocompatible, hemocompatible with size, polydispersity index, and zeta potential of 169.2 ± 1.6 nm, 0.21 ± 0.01 and −0.82 ± 0.22 mV, respectively. Under acidic conditions, mPEG-OA-coated niosomes exhibited a pH-responsive and sustained VCM release profile and in vitro antibacterial activity than non-coated niosomes and bare VCM. mPEG-OA-coated niosomes showed a significant reduction in biofilm formation at pH 6 compared to pH 7.4 (p = 0,0119). The in vivo efficacy of mPEG-OA-coated niosomes in the BALB/c mice skin infection model showed a 9.9-fold reduction in MRSA load compared to bare VCM. Histomorphologically, the mPEG-OA-coated niosomes group displayed the lowest bacterial load, tissue swelling, and inflammation. The results of this study demonstrate the potential of novel pH-responsive mPEG-OA-derived polymer coating to enhance bacterial killing kinetics, and antibacterial and anti-biofilm efficacies over conventional antibiotic and non-functionalized nano delivery systems.