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Abstract: The objective of this study was to develop and evaluate the antitumor activity and the safety of a delivery system containing mesoporous silica nanoparticles (MSN) coated with pH-responsive poly (N-isopropylacrylamide-co-methacrylic acid; P NIPAM-co-MAA) for doxorubicin (DOX) delivery (P-MSN-DOX) in vitro and in vivo. We reported that P-MSN-DOX nanoparticles (190±30nm) offered a DOX-loading coefficient of more than 20%. DOX release from the P-MSN-DOX formulation was pH-dependent with enhanced antitumor effects in vitro compared with traditional MSN-DOX, which was weakly cytotoxic due to negligible drug release at tested pHs. P-MSN-DOX circulated longer, with less cardiac and renal accumulation as shown by pharmacokinetics and biodistribution studies in vivo. Also, the P-MSN-DOX delivery system had greater antitumor activity in mice bearing a murine sarcoma S-180 cell line. This finding was correlated with both in vitro and in vivo. Subacute toxicity tests revealed a low P-MSN-DOX toxicity in vivo, as well. Thus, P-MSN-DOX appears to be an efficacious and safe cancer treatment strategy. [Copyright &y& Elsevier]

Nanoscale poly(alkyl methacrylate)s including poly(methyl methacrylate), poly(ethyl methacrylate), poly(cyclohexyl methacrylate), poly(iso-butyl methacrylate) and poly(benzyl methacrylate) were prepared by a modified microemulsion polymerization procedure. NMR analysis suggested that these poly(methacrylate)s samples were higher in syndiotactic content, lower in isotactic content and the glass transition temperatures (Tgs) of them were also higher than those reported in the literature. The tacticities of the poly(methacrylate)s, beside the restricted volume effect of nanoparticles during the modified microemulsion polymerization, were mainly influenced by the reaction temperature, the lower the reaction temperature, the higher the syndiotacticity of the products. The syndiotacticity of the product decreased obviously when the polymerization was carried out at a temperature far above the Tg of the resulting polymer. It was also shown that the tacticity of the polymer was affected by the monomer structure, a monomer with the bulkier alkyl side group would liable to result in a polymer with richer syndiotacticity. Possible mechanism of rich-syndiotacticity was also discussed. [ABSTRACT FROM AUTHOR]

Abstract: New nonstoichiometric polyelectrolyte complex nanoparticles were prepared based on chitosan (CS) and polyaspartic acid sodium salt (PAsp). The physicochemical properties of the complexes were investigated by means of turbidity, dynamic light scattering, transmission electron microscopy and zeta potential. The results indicated that the slow dropwise addition of chitosan into PAsp allowed to elaborate either anionic or cationic particles in the size range of 85–300nm with proper CS and PAsp unit molar ratios. Investigation of structural changes during the addition of CS revealed that the microstructure of the nanoparticles depended strongly on the unit molar ratio of CS to PAsp. Nanoparticles containing a hydrophilic drug, 5-fluorouracil (5FU), were prepared by mixing and absorption method. In vitro and in vivo experiment indicated that the drug-loaded CS–PAsp nanoparticles presented a sustained release of 5FU compared to the 5FU solution and the areas under curve (AUC) were increased by about four times. [Copyright &y& Elsevier]

Hyperbranched poly(amido amine) (h-PAMAM) was synthesized from different feed ratios of diethylene triamine and methyl acrylate by the simple one-pot and commercial synthesis method. Reaction procedures and products were intensively studied by FTIR, inherent viscosity and fluorescence techniques. The ill-structured h-PAMAM shared similar chemical and physical properties with well defined poly(amido amine) (PAMAM) dendrimers in generation 2 or 3. Its strong fluorescence properties were influenced by pH values, solvents, concentrations, terminal groups and other factors. [ABSTRACT FROM AUTHOR]

Abstract: The ammonium glycyrrhizinate-loaded chitosan nanoparticles were prepared by ionic gelation of chitosan with tripolyphosphate anions (TPP). The particle size and zeta potential of nanoparticles were determined, respectively, by dynamic light scattering (DLS) and a zeta potential analyzer. The effects, including chitosan molecular weight, chitosan concentration, ammonium glycyrrhizinate concentration and polyethylene glycol (PEG) on the physicochemical properties of the nanoparticles were studied. These nanoparticles have ammonium glycyrrhizinate loading efficiency. The encapsulation efficiency decreased with the increase of ammonium glycyrrhizinate concentration and chitosan concentration. The introduction of PEG can decrease significantly the positive charge of particle surface. These studies showed that chitosan can complex TPP to form stable cationic nanoparticles for subsequent ammonium glycyrrhizinate loading. [Copyright &y& Elsevier]

Abstract: Monte Carlo simulation of chemically reacting systems based on the master equation was used to describe the stochastic time evolution of the microemulsion polymerization system. A model was developed to demonstrate its applicability for hexyl methacrylate and styrene microemulsion polymerization. The properties of final latex, such as the particle size and molecular weight distributions were obtained simultaneously. The polymerization behavior and properties of final latexes were well reproduced. The model is valuable in confirming or elucidating the various mechanisms in the polymerization. The entry and desorption mechanism was well established to account for the polymerization kinetics. The general polymerization behavior of hydrophobic monomer in microemulsions was properly simulated by the model proposed. [Copyright &y& Elsevier]

Nanoscale poly(ethyl methacrylate) (PEMA) particles were prepared by a monomer post-added microemulsion polymerization procedure. ¹H NMR analysis suggested that the PEMA samples were rich in syndiotactic content (58-64% rr) and lower in isotactic content (4-6%mm). The glass transition temperatures (Tg's) of the products were also higher than those of the PEMA samples prepared by ordinary free-radical polymerization. The polymer properties, such as particle size, molecular weight, tacticity, and Tg were affected by the reaction conditions. The smaller the particle size, the higher the syndiotacticity, the lower the isotacticity, the greater the molecular weight, then the higher the Tg of PEMA. A possible mechanism of rich-syndiotacticity was also discussed primarily. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, novel thermosensitive poly(N-isopropylacrylamide) (PNIPAM) nanocapsules with temperature-tunable diameter and permeability are reported. Firstly, the core-shell composite microparticles were synthesized by precipitation polymerization with isothiocyanate fluorescein (FITC) entrapped SiO2 as core and cross-linked PNIPAM as shell. Then, the SiO2 core was etched by hydrofluoric acid at certain condition and the pre-trapped FITC molecules remained within the inner cavity. The FITC release profile and TEM studies clearly indicate that the release behavior of FITC could be controlled effectively by the external temperature. Above the LCST of PNIPAM (32°C), the dehydrated PNIPAM shell inhibited the release of FITC from the internal cavity while below its LCST, the fluorophore could permeate the swollen shell easily. [Copyright &y& Elsevier]

Zeolite β, silicalite-1, ZSM-5, and TS-1 coated spheres have been prepared successfully through layer-by-layer assembly of nanozeolite/polymer multilayers on polystyrene (PS) microspheres, and hollow zeolite spheres have been obtained by removal of the core by calcination. In the adsorption process of nanozeolites onto the polyelectrolyte-modified template spheres, it has been found that zeta potential of the zeolite colloidal solution that determines the electrostatic interaction has important effects on the zeolite adsorption procedure. The charge on the original sphere template is not necessary, because proper polyelectrolyte modification could change the surface property of the template and make it suitable for layer-by-layer adsorption. The influences of zeolite type and/or size (40–120 nm), the number of zeolite/poly(diallyl-dimethyl-ammonium) layer pairs, and the template sphere size (0.53–10.3 µm) on the preparation of the hollow zeolite spheres were also discussed. [ABSTRACT FROM AUTHOR]

Copolymer microspheres consisting of styrene and N-vinyl carbazole (NVC) have been prepared by dispersion polymerization. The effects of various polymerization parameters on the particle size were systematically studied. The particle size increased with the decrease of the system's initial solubility parameter and stabilizer concentration. When a small amount of inhibitor was added into the system, the particle size notably increased and the particle size distribution widened. The ratio of styrene to NVC in the monomer mixture had no obvious effect on particle size. The amount of NVC in the copolymers increases with the increase of NVC in the monomers. [ABSTRACT FROM AUTHOR]

The heterogeneity of triple‐negative breast cancers (TNBC) remains challenging for various treatments. Ferroptosis, a recently identified form of cell death resulting from the unrestrained peroxidation of phospholipids, represents a potential vulnerability in TNBC. In this study, a high intensity focused ultrasound (HIFU)‐driven nanomotor is developed for effective therapy of TNBC through induction of ferroptosis. Through bioinformatics analysis of typical ferroptosis‐associated genes in the FUSCCTNBC dataset, gambogic acid is identified as a promising ferroptosis drug and loaded it into the nanomotor. It is found that the rapid motion of nanomotors propelled by HIFU significantly enhanced tumor accumulation and penetration. More importantly, HIFU not only actuated nanomotors to trigger effective ferroptosis of TNBC cells, but also drove nanomotors to activate ferroptosis‐mediated antitumor immunity in primary and metastatic TNBC models, resulting in effective tumor regression and prevention of metastases. Overall, HIFU‐driven nanomotors show great potential for ferroptosis‐immunotherapy of TNBC. [ABSTRACT FROM AUTHOR]

The potential of microRNA regulation in oncotherapy is limited by the lack of delivery vehicles. Herein, it is shown that fluoropolymer coated DNA nanoclews (FNCs) provide outstanding ability to deliver oligonucleotide through circulation and realize near infrared (NIR) light activated angiogenesis suppression to abrogate tumors. Oligonucleotides are loaded in DNA nanoclews through sequence specific bindings and then a fluorinated zwitterionic polymer is coated onto the surface of nanoclews. Further incorporating quantum dots in the polymer coating endows the vectors with NIR‐IIb (1500–1700 nm) fluorescence and NIR light triggered release ability. The FNC vector can deliver oligonucleotides to cancer cells systemically and realize on‐demand cytosolic release of the cargo with high transfection efficiency. Taking advantage of the NIR‐IIb emission, the whole delivery process of FNCs is visualized volumetrically in vivo with a NIR light sheet microscope. Loaded by FNCs, an oligonucleotide can effectively silence the target miRNA when activated with NIR light, and inhibit angiogenesis inside tumor, leading to complete ablation of cancer. These findings suggest FNCs can be used as an efficient oligonucleotide delivery platform to modulate the expression of endogenous microRNA in gene therapy of cancer. [ABSTRACT FROM AUTHOR]

Cross-linked polymer microspheres are widely used in biomedicine, flat panel display, analytical testing, in vitro diagnostics, semiconductor chips, and light diffusion. However, the process of preparing micron-sized cross-linked polymer microspheres is complicated, and it is difficult to obtain a high crosslinking degree conveniently. In this work, we applied post-crosslinking strategy to prepare poly (methyl methacrylate) (PMMA) microspheres having a high crosslinking degree by dispersion polymerization, while the method separated the polymerization process and cross-linking process of microspheres. In the method, the silane coupling agents containing double bonds were used as the comonomer in polymerization and hydrolyzed to form Si–O–Si cross-linked structure at the later stage. The obtained microspheres are not only highly cross-linked but also have uniform particle size distribution and good thermal stability. The produced cross-linked PMMA microspheres exhibit great light diffusion properties and might be employed as a light diffusion agent in a polycarbonate matrix. We prepared the cross-linked PMMA microspheres by post-crosslinking method and mixed the cross-linked PMMA microspheres with the matrix PC to obtain the light diffusers. [ABSTRACT FROM AUTHOR]

Review: 115 refs. [ABSTRACT FROM AUTHOR]

The development of stimuli‐responsively degradable porous carriers for both controlled drug release and high biosafety is vitally important to their clinical translation, but still challenging at present. A new type of porphyrin–iron metal organic framework (Fe‐MOF) nanocrystals is engineered here as acid‐degradable drug carrier and hydrogen donor by the coordination between porphyrin and zero‐valence Fe atom. Fe‐MOF nanocrystals exhibit excellent acid‐responsive degradation for H2 generation and simultaneous release of the loaded drug for combined hydrogen‐chemotherapy of cancer multidrug resistance (MDR) and metastasis and for local hydrogen eradication of the off‐target induced toxic side effects of the drug to normal cells/tissues. Mechanistically, released H2 assists chemotherapeutic drug to efficiently inhibit cancer metastasis by immunoactivating intratumoral M1‐phenotype macrophages and consequently downregulating the expression of metastasis‐related matrix metalloproteinase‐2 (MMP‐2) and can also downregulate the expressions of both P‐glycoprotein (P‐gp) protein and adenosine triphosphate (ATP) in MDR cancer cells to sensitize chemotherapeutic drug for enhanced damage to mitochondria and DNA. High anti‐MDR/antimetastasis efficacies and high biocompatibility endow Fe‐MOF nanocrystals and the Fe‐MOF‐based nanomedicine with high potential for clinical translation. [ABSTRACT FROM AUTHOR]

ABSTRACT The synthesis and characterization of a new photocleavable crosslinker is presented here. Dual stimuli-responsive P(VCL- co-NHMA) microgels were prepared by precipitation polymerization of vinylcaprolactam (VCL) with N-hydroxymethyl acrylamide (NHMA) and the new crosslinker. The microgels had distinct temperature sensitivity as observed in the case of PVCL-based particles and their volume phase transition temperature (VPTT) shifted to higher temperature with increasing NHMA content. Photolytic degradation experiments were investigated by irradiation with UV light, which led to microgel disintegration caused by cleavage of the photolabile crosslinking points. The degradation behavior of the microgels was conducted with respect to degradation rates by means of the relative turbidity changes. Hence, the microgels could totally degrade into short linear polymers by UV light, thus representing a great potential as new light and temperature dual responsive nanoscale materials. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1676-1685 [ABSTRACT FROM AUTHOR]

Exenatide −loaded PLGA microspheres were prepared via the water/oil/water (W/O/W) emulsion method using the microfluidic device. [Display omitted] • Ext-loaded PLGA microspheres with good monodispersity were prepared using the microfluidic device. • The critical quality attributes of peptide-loaded microspheres and their influencing factors were systematically studied. • The designed microfluidic device had the capability to operate in a highly parallel manner. It is challenging for the manufacturing of microspheres loaded with peptide due to the complicated preparation process and the issue of burst release. In this construct, a microfluidic flow-focusing device is developed to prepare and optimize poly (lactic- co -glycolic acid) (PLGA) Exenatide −loaded microspheres. Surfactants was added to greatly improve the stability of the emulsion, leading to increase drug loading capacity. By increasing the particle size of the drug-loaded microspheres to 30 μm, the burst release was significantly reduced. Additionally, multi-channel droplet microfluidic devices are prepared with the capability to achieve a 100-fold increase in throughput, which could achieve a production rate of 2 g per hour. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ferroptosis could effectively kill cancer cells because of their high-loaded reactive oxygen species (ROS), metabolic mutations, and increased requirement for an iron supply. • Ferric metal–organic frameworks (Fe-MOFs) function as nanoplatforms to co-deliver iron ions and a ferroptosis inducer, atorvastatin (ATV), to cancer cells. • The glutathione (GSH)-degradable zwitterionic polymer membrane (PMPC) coated on the surface endowed Fe-MOFs with enhanced stability and long circulation time. • When internalized by cancer cells, these nanoparticles were degraded by GSH, to deplete GSH and release ATV and Fe2+. • The ferroptosis mechanism of this nanoplatform was elucidated. Ferroptosis inhibits tumor growth by iron-dependently accumulating lipid peroxides (LPO) to a lethal extent, which can result from iron overload and glutathione peroxidase 4 (GPX4) inactivation. In this study, we developed biodegradable zwitterionic polymer-cloaked atorvastatin (ATV)-loaded ferric metal–organic frameworks (Fe-MOFs) for cancer treatment. Fe-MOFs served as nanoplatforms to co-deliver ferrous ions and ATV to cancer cells; the zwitterionic polymer membrane extended the circulation time of the nanoparticles and increased their accumulation at tumor sites. In cancer cells, the structure of the Fe-MOFs collapsed in the presence of glutathione (GSH), leading to the depletion of GSH and the release of ATV and Fe2+. The released ATV decreased mevalonate biosynthesis and GSH, resulting in GPX4 attenuation. A large number of reactive oxygen species were generated by the Fe2+-triggered Fenton reaction. This synergistic effect ultimately contributed to a lethal accumulation of LPO, causing cancer cell death. The findings both in vitro and in vivo suggested that this ferroptosis-inducing nanoplatform exhibited enhanced anticancer efficacy and preferable biocompatibility, which could provide a feasible strategy for anticancer therapy. [ABSTRACT FROM AUTHOR]

Objective. To develop a real-time imaging method to identify the rat stomach lymph node basin with quantum dots (Qdots). Material and methods. Six Sprague-Dawley rats received injections of 0.05 ml Qdots (1 mg/ml) in the subserosal layer in the lesser curvature of the gastric antrum. Subsequently, draining lymphatic channels and lymph nodes were visualized with a near-infrared fluorescence imaging system. Histological examination was required to confirm the presence of lymph nodes. Additionally, rats received injections of Qdots and underwent 2 weeks of observation to confirm if there was any abnormality. The distribution of Qdots was measured by inductively coupled plasma-mass spectrometry. Results. After injection of the Qdots, the gastric sentinel lymph nodes were visualized 15 min later. The fluorescence then began to spread. The intensity of fluorescence increased in the perigastric area at 60 min, and declined at 360 min. Histological analysis of the fluorescent tissue confirmed the presence of nodal tissue. The results of a cadmium assay showed that Qdots were mainly distributed in the liver, spleen and kidney of the rats. No apparent toxicity could be seen during the 2 weeks of observation. Conclusions. NIR fluorescence imaging of lymph nodes with Qdots is a novel and reliable real-time technique that can be used to assist with identification and resection of stomach lymph nodes. The optimal observation time of perigastric SLNs was 15 min after the injection, and the optimal observation time of perigastric lymph nodes beyond the SLNs was 60-120 min after the injection. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a simple approach was presented to prepare functional inorganic/organic composite microspheres in which the inorganic nanoparticles were encapsulated into the polyelectrolyte complexes between chitosan (CS) and poly(aspartic acid) sodium salt (PAsp). The magnetic microspheres were prepared via electrostatic interaction between the citrate groups stabilizing Fe3O4 nanoparticles and the amino groups of CS. Being taken as a kind of special polyelectrolyte with high molecular weight, the inorganic nanoparticles presented strong interaction with polyelectrolyte. By tuning the unit molar ratio of the opposite charged polyelectrolytes and the amount of Fe3O4 nanoparticles, the structure of the composite microspheres could be controlled and the dimension of microspheres ranged from 110 nm to 320 nm. Then the approach was extended to prepare luminescent-magnetic CS–PAsp microspheres by encapsulated Fe3O4 nanoparticles and CdTe quantum dots synchronously, which exhibited superior pH stability and remained strong photoluminescence properties after crosslinking. The CdTe–Fe3O4/CS–PAsp composite microspheres are potentially useful for further application in biolabeling and imaging. [Copyright &y& Elsevier]

Nanoscale poly(cyclohexyl methacrylate) (PCHMA) particles were prepared by a modified microemulsion polymerization procedure. 13C-NMR analysis suggested that such PCHMA samples were higher in syndiotactic content (61-72% rr) and lower in isotactic content (1-3% mm). The glass transition temperatures (Tg's) of the products were also higher than that reported in the literature. The polymer properties, such as particle size, molecular weight, tacticity, and Tg were affected by the reaction conditions. The smaller the particle size, the higher the syndiotacticity, the lower the isotacticity and the greater the molecular weight, then the higher the Tg of the PCHMA samples. Possible mechanism of rich-syndiotacticity was also discussed. [ABSTRACT FROM AUTHOR]

Abstract: A modified method to prepare chitosan–poly(acrylic acid)(CS–PAA) polymer magnetic microspheres was reported in this paper. First, via self-assembly of positively charged CS and negatively charged Fe3O4 nanoparticles, magnetic CS cores with a large amount of Fe3O4 nanoparticles were successfully prepared. Subsequently, the AA monomers were polymerized on the magetic CS cores based on the reaction system of water-soluble polymer–monomer pairs. These polymer magnetic microspheres had a high Fe3O4 loading content, and showed unique pH-dependent behaviors on the size and zeta potential. From the magnetometer measurements data, the CS–PAA polymer magnetic microspheres also had superparamagnetic property as well as fast magnetic response. A continuous release of the entrapped ammonium glycyrrhizinate in such polymer magnetic microspheres occurred, which confirmed the potential applications of these microspheres for the targeted delivery of drugs. [Copyright &y& Elsevier]

A suitable carrier chitosan (CS) was used to prepare CS-Glycyrrhetic acid (GLA) nanoparticles under very mild conditions by polyelectrolyte complexation. These nanoparticles were well dispersed and stable in aqueous solution, and the physicochemical properties of which were investigated by FT-IR, dynamic light scattering, transmission electron microscope, fluorescence spectra and zeta potential. It was found that only when the weight ratio of CS to GLA was lower than 16.7, could the nanoparticles be formed. The prepared nanoparticles carried a positive charge and had the dried TEM-assessed size in the range from 20 to 30 nm. The mean hydrated diameter, size distribution and zeta potential of the nanoparticles could be controlled by some factors including the weight ratio of CS to GLA, the average molecular weight of CS and the pH value of the medium. It was also found that GLA encapsulation efficiency into the nanoparticles increased with the increase of the weight ratio of CS to GLA. The experiment of GLA release in vitro showed that the effect of CS encapsulation on GLA release was obvious and the CS-GLA nanoparticles system might be used to provide a continuous release. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95:181–191, 2006 [ABSTRACT FROM AUTHOR]

Semi-transparent reactive microgel in nanosize has been prepared by modified microemulsion polymerization using a common emulsifier, crosslinking agent and functional monomer. The microgels are translucent reactive nanoparticles, with the size of 40–100 nm, consisting of inner-crosslinked polymer up to 40%. FT-IR proved the functional groups, such as epoxy and hydroxy, are on the surface of the microgel nanoparticles. Rheological detection demonstrated the apparent pseudoplasticity of the non-aqueous microgel dispersion prepared by the phase transfering from the O/W microlatexes. [ABSTRACT FROM AUTHOR]

Abstract: Water soluble chitosan (CS) derivatives containing polylactide unit were synthesized by reacting dl-lactide (DLLA) with chitosan in dimethyl sulfoxide solution in the presence of triethylamine. The chemical structure and physical properties of chitosan derivatives were characterized by FTIR, 1HNMR, TGA and XRD. Formation and characteristics of polymeric micelles of graft copolymers were studied by fluorescence spectroscopy and dynamic light scattering (DLS) method. The critical micelles concentration (cmc) of polymeric amphiphiles was determined by measuring the fluorescence intensity of pyrene as a fluorescent probe. The cmc value of DLLA/CS (11:1) (dl-lactide/aminoglucoside units molar ratio=11:1) in water was 6.49×10-2mg/ml. The size of micelles and their size distribution in water were measured by DLS. Mean diameter of the polymeric amphiphiles micelles of DLLA/CS (11:1) in water was 154nm with an unimodal size distribution (polydispersity=μ/Γ2=0.03). The spherical micelles were observed by transmission electron microscopy (TEM). [Copyright &y& Elsevier]

Thin zeolite films with thicknesses from several hundred nanometers to a few micrometers have been fabricated through electrophoretic deposition (EPD) in acetylacetone (Acac) and/or isopropyl alcohol (IPA). Various types of nanosized zeolites with different Si/Al ratios ranging from 1.6 (zeolite LTA) to nearly infinity (silicalite-1) were applied to prepare the EPD suspensions and showed different behaviors in EPD. The EPD rate of zeolite particles in non-aqueous medium was much higher than that in aqueous system mainly due to the high voltage applied, and consequently the whole process was usually completed in a few seconds. It was found that the Al/(Si + Al) ratios of zeolites and the chemical/physical properties of the EPD medium were two crucial factors which affected the thickness and density of the zeolite films prepared by EPD. The zeolite films fabricated through EPD could be effectively densified by secondary growth to prepare compact zeolite membranes. [Copyright &y& Elsevier]

A fluorophore-enriched polymer was synthesized through modification of a kind of copolymer by fluorescein isothiocyanate (FITC). The copolymer was obtained by batch emulsion polymerization of t-butyl acrylate (t-BA) and an amino-containing monomer M2, which was produced in our laboratory. According to various characterizations, such as gel permeability chromatography (GPC), 1H-NMR, fluorescence spectroscopy, the amount of amino and fluorescein groups of the obtained fluorescent polymer could be controlled and its polarity could be converted from hydrophobic to hydrophilic through hydrolysis. These water-soluble fluorescent polymers had a high luminescence, which were visible under the conventional microscope. Such an advantage made them suitable for further bioconjunction as probes with their targets, such as biomacromolecules and cells. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC), a management of aggressive breast cancer, remains an unmet medical challenge. Although a wave of efforts had spurred to design novel therapeutic method of TNBC, unpredictable prognosis with lacking effective therapeutic targets along with the resistance to apoptosis seriously limited survival benefits. Ferroptosis is a non-apoptotic form of cell death that is induced by excessive lipid peroxidation, which provide an innovative way to combat cancer. Emerging evidence suggests that ferroptosis plays an important role in the treatment of TNBC cells. Herein, a novel ferroptosis nanomedicine was prepared by loading simvastatin (SIM), a ferroptosis drug, into zwitterionic polymer coated magnetic nanoparticles (Fe3O4@PCBMA) to improve the therapeutic effect of TNBC. The as-obtained Fe3O4@PCBMA-SIM nanoparticles demonstrated more cytotoxicity against MDA-MB-231 than MCF-7 due to the higher expression of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR), which demonstrated that statins could effectively kill TNBC. Further experiments showed that SIM could inhibit the expression of HMGCR to downregulate the mevalonate (MVA) pathway and glutathione peroxidase 4 (GPX4), thereby inducing cancer cell ferroptosis. What's more, PCBMA endows Fe3O4@PCBMA longer blood circulation performance to enhance their accumulation at tumor sites. Given that Fe3O4 have proven for clinical applications by the U.S. Food and Drug Administration (FDA) and SIM could induce cancer cell ferroptosis, the developed Fe3O4@PCBMA-SIM nanosystem would have great potential in clinics for overcoming the drug resistance brought about by apoptotic drugs to cancer cells. [ABSTRACT FROM AUTHOR]

Herein, acrylonitrile-styrene-acrylate copolymer (ASA) particles with different microstructure were synthesized by emulsion polymerization and then used for toughening poly(styrene-co-acrylonitrile) (SAN) resin. The structure of ASA particles was confirmed by FTIR. TEM results demonstrated that the particles with different morphologies of multilobe shape, complete core-shell and dumbbell shape were obtained depending on the cross-linker amount. It was found that the toughening efficiency reached the highest when the ASA particles had complete core-shell structure and the shell composition was close to that of the SAN matrix. It was ascribed to the fact that the complete shell layer and similar shell composition provided sufficient interfacial adhesion and transferred stress to induce larger matrix deformation, so that the notched impact strength increased accordingly. Moreover, the notched impact strength of SAN/ASA blend was improved without significantly sacrificing tensile strength when adding 30 wt% ASA particles with the size of around 400 nm. SEM results of the impact-fractured surfaces revealed that irregular fluctuation and numerous microvoids occurred. It was deduced that the toughening mechanism was attributed to the crazings and cavitation of particles. Therefore, this study paved a way of toughening the resin by adjusting the microstructure of the particles including morphology, composition, and size. [ABSTRACT FROM AUTHOR]

A series of hexylamine modified polysuccinimide (PSI–HA) copolymers were synthesized by aminolysis of polysuccinimide (PSI) with hexylamine. FTIR and 1H NMR measurements confirmed the structure of the copolymers and the substitution degree of the N-hexyl aspartamide units ranged from 7 to 92 mol%. Stable nanoparticles formed when the DMF solution of PSI–HA copolymers was dropped into excess water, and the particle size reduced as increasing the substitution degree. 1H NMR analysis indicated that hexyl chain and succinimide units interacted to form the hydrophobic core, while, the nanoparticles were stabilized by the amide groups which formed hydrogen bonds with the surrounding water molecules. The nanoparticles became more compact at higher temperature due to the break of hydrogen bonds between amide groups and water molecules. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) results showed that the nanoparticles were nearly spherical. Larger nanoparticles formed when the dispersion concentration increased from 0.1% to 1.0% according to the DLS and steady-state fluorescence measurements. After the nanoparticles formed in water, a sequential dilution can't influence the particles size of the nanoparticles any longer. [ABSTRACT FROM AUTHOR]

Electron transfer is the rate‐limiting step in photocatalytic water splitting. Viologen and its derivatives are able to act as electron‐transfer mediators (ETMs) to facilitate the rapid electron transfer from photosensitizers to active sites. Nevertheless, the electron‐transfer ability often suffers from the formation of a stable dipole structure through the coupling between cationic‐radical‐containing viologen‐derived ETMs, by which the electron‐transfer process becomes restricted. Herein, cyclic diquats, a kind of viologen‐derived ETM, are integrated into a 2,2′‐bipyridine‐based covalent organic framework (COF) through a post‐quaternization reaction. The content and distribution of embedded diquat‐ETMs are elaborately controlled, leading to the favorable site‐isolated arrangement. The resulting materials integrate the photosensitizing units and ETMs into one system, exhibiting the enhanced hydrogen evolution rate (34600 μmol h−1 g−1) and sustained performances when compared to a single‐module COF and a COF/ETM mixture. The integration strategy applied in a 2D COF platform promotes the consecutive electron transfer in photochemical processes through the multi‐component cooperation. [ABSTRACT FROM AUTHOR]

Electron transfer is the rate‐limiting step in photocatalytic water splitting. Viologen and its derivatives are able to act as electron‐transfer mediators (ETMs) to facilitate the rapid electron transfer from photosensitizers to active sites. Nevertheless, the electron‐transfer ability often suffers from the formation of a stable dipole structure through the coupling between cationic‐radical‐containing viologen‐derived ETMs, by which the electron‐transfer process becomes restricted. Herein, cyclic diquats, a kind of viologen‐derived ETM, are integrated into a 2,2′‐bipyridine‐based covalent organic framework (COF) through a post‐quaternization reaction. The content and distribution of embedded diquat‐ETMs are elaborately controlled, leading to the favorable site‐isolated arrangement. The resulting materials integrate the photosensitizing units and ETMs into one system, exhibiting the enhanced hydrogen evolution rate (34600 μmol h−1 g−1) and sustained performances when compared to a single‐module COF and a COF/ETM mixture. The integration strategy applied in a 2D COF platform promotes the consecutive electron transfer in photochemical processes through the multi‐component cooperation. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC) causes great suffering to patients because of its heterogeneity, poor prognosis, and chemotherapy resistance. Ferroptosis is characterized by iron-dependent oxidative damage by accumulating intracellular lipid peroxides to lethal levels, and plays a vital role in the treatment of TNBC based on its intrinsic characteristics. To identify the relationship between chemotherapy resistance and ferroptosis in TNBC, we analyzed the single cell RNA-sequencing public dataset of GSE205551. It was found that the expression of Gpx4 in DOX-resistant TNBC cells was significantly higher than that in DOX-sensitive TNBC cells. Based on this finding, we hypothesize that inducing ferroptosis by inhibiting the expression of Gpx4 can reduce the resistance of TNBC to DOX and enhance the therapeutic effect of chemotherapy on TNBC. Herein, dihydroartemisinin (DHA)-loaded polyglutamic acid-stabilized Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 -PGA-DHA) was combined with DOX-loaded polyaspartic acid-stabilized Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 -PASP-DOX) for ferroptosis-enhanced chemotherapy of TNBC. Compared with Fe 3 O 4 -PASP-DOX, Fe 3 O 4 -PGA-DHA + Fe 3 O 4 -PASP-DOX demonstrated significantly stronger cytotoxicity against different TNBC cell lines and achieved significantly more intracellular accumulation of reactive oxygen species and lipid peroxides. Furthermore, transcriptomic analyses demonstrated that Fe 3 O 4 -PASP-DOX-induced apoptosis could be enhanced by Fe 3 O 4 -PGA-DHA-induced ferroptosis and Fe 3 O 4 -PGA-DHA + Fe 3 O 4 -PASP-DOX might trigger ferroptosis in MDA-MB-231 cells by inhibiting the PI3K/AKT/mTOR/GPX4 pathway. Fe 3 O 4 -PGA-DHA + Fe 3 O 4 -PASP-DOX showed superior anti-tumor efficacy on MDA-MB-231 tumor-bearing mice, providing great potential for improving the therapeutic effect of TNBC. [ABSTRACT FROM AUTHOR]

Cross-linked poly(methyl methacrylate) (PMMA) microspheres have been successfully prepared by using the asymmetric cross-linker allyl methacrylate (AMA) via dispersion polymerization. The influence of the AMA amount and polymerization process on the PMMA particle size and morphology has been studied thoroughly. It was found that micron-sized, cross-linked PMMA particles with narrow size distributions could be obtained by a semi-continuous process with the asymmetric cross-linker AMA. The obtained micron-sized, cross-linked PMMA particles could be further used as a light diffusion agent in a polycarbonate matrix, and their light diffusion properties were significantly enhanced by increasing the gel content in the cross-linked particles. Moreover, the influence of the polymerization process, cross-linker content in PMMA and PMMA content in the polycarbonate matrix on light diffusion was carefully investigated. The results showed that the PMMA particles containing 5.0 wt% AMA, obtained by semi-continuous polymerization, had a higher haze and gel content and exhibited a better light diffusion effect than did the other particles. [ABSTRACT FROM AUTHOR]

Abstract A multifunctional CO/thermo/chemotherapy nanoplatform is here reported, which is composed of mesoporous carbon nanoparticles (MCN) as near infrared (NIR)-responsive drug carrier, doxorubicin (DOX) as chemotherapeutic drug and triiron dodecacarbonyl (FeCO) as thermosensitive CO prodrug. The nanoplatform could absorb near-infrared (NIR) light and convert it into ample heat to trigger CO release and could also release DOX in the acidic tumor microenvironment. More importantly, the generated CO molecules successfully increase cancer cell sensitivity to chemotherapeutics by the ferroptosis pathway. Subsequently, under the guidance of photoacoustic imaging, the FeCO-DOX@MCN nanoplatform demonstrates high treatment efficacies in vitro and in vivo by combination of chemotherapy, photothermal therapy and gas therapy. This multifunctional platform with excellent antitumor efficacy has great potential in precision cancer therapy. [ABSTRACT FROM AUTHOR]

Graphical abstract Biodegradable phosphorylcholine-based zwitterionic polymer nanogels with charge-conversion ability at tumor extracellular pH were fabricated by one-step reflux precipitation polymerization, leading to the enhanced tumor cellular uptake and controlled drug release. Abstract Zwitterionic polymer nanocarriers have attracted much attention in recent years due to their desirable biocompatibility and anti-fouling properties. However, the super-hydrophilic and neutral charge of zwitterionic polymer results in weak interactions with negatively charged cell membranes, which leads to suboptimal uptake by tumor cells. Herein, a series of biodegradable poly(2-methacryloyloxyethyl phosphorylcholine- s-s -vinylimidazole) (PMV) nanogels with uniform spherical shape was fabricated by one-step reflux precipitation polymerization, which was clean and efficient. The PMV nanogels remained in zwitterionic state at physiological pH (pH 7.4) and were converted rapidly to positive charged state at tumor extracellular pH (pH 6.5). Proton nuclear magnetic resonance spectra and acid-base titration experiment proved that the charge-conversion ability of PMV nanogels was attributed to protonation of the imidazole ring in an acidic environment. Protein stability experiment showed that PMV nanogels exhibited a protein-adsorption resistance at pH 7.4 for as long as 7 days while adsorbed protein rapidly at pH 6.5. Moreover, PMV nanogels showed a reducing-labile property, which was able to degrade into short linear polymer chains in the presence of reduction agents. Therefore, the doxorubicin (DOX) release profile was controlled finely with a low DOX leakage under physiological conditions (7.8% in 48 h) and a rapid DOX release in 10 mM glutathione at pH 7.4 (78.9% in 48 h). Confocal laser scanning microscope and flow cytometry showed that the PMV nanogels exhibit an enhanced cellular uptake by tumor cells at pH 6.5 compared with pH 7.4, which allows for a severe cytotoxic effect of DOX-loaded PMV nanogels against tumor cells. [ABSTRACT FROM AUTHOR]

Abstract Carbon monoxide (CO) gas therapy combined with chemotherapy and photothermal therapy (PTT) is a promising treatment mode for malignant tumor. Herein, we firstly reported doxorubicin (DOX) loaded Mn carbonyl modified Fe (Ⅲ)-based nanoMOFs (MIL-100) coated PEGylated magnetic carbon nanoparticles (denoted as MCM@PEG-CO-DOX NPs) as theranostics nanoplatforms for near-infrared (NIR)-responded CO-DOX combination therapy. MIL-100 as a good nanocarrier of DOX with high loading capacity can also chelate the Mn carbonyl after a smart modification. Meanwhile, magnetic carbon core possessed photothermal effect, which can convert the NIR light to heat by an 808 nm laser irradiation, resulting in the on-demand release of CO and DOX. As a result, combining with PTT, MCM@PEG-CO-DOX NPs killed tumor efficiently. Moreover, our synthesized MCM@PEG-CO-DOX NPs were capable of realizing tumor dual-mode imaging including magnetic resonance imaging (MRI) and photoacoustic imaging (PAI). [ABSTRACT FROM AUTHOR]

Abstract Cell membrane coating has emerged as an intriguing biomimetic strategy to endow nanomaterials with functions and properties inherent to source cells for various biomedical applications. Hybrid membrane of different types of cells could be coated onto nanoparticle surface to achieve additional functions. Herein, we fused red blood cell (RBC) membrane together with MCF-7 cell membrane and fabricated an erythrocyte-cancer (RBC-M) hybrid membrane-camouflaged melanin nanoparticle (Melanin@RBC-M) platform for enhancing therapeutic efficacy of photothermal therapy (PTT). The fused RBC-M hybrid membrane vesicles retained both RBC and MCF-7 cell membrane proteins and the resultant Melanin@RBC-M exhibited prolonged blood circulation and homotypic targeting to source MCF-7 cells simultaneously. Interestingly, increasing MCF-7 membrane components in RBC-M significantly enhanced the homotypic targeting function of Melanin@RBC-M while increasing RBC membrane components in RBC-M effectively reduced the cellular uptake of Melanin@RBC-M by macrophages and improved their circulation time in the blood. After intravenous injection into MCF-7 tumor-bearing athymic nude mice, Melanin@RBC-M with 1:1 membrane protein weight ratio of RBC to MCF-7 exhibited significantly higher tumor accumulation and better PTT efficacy compared with other Melanin@RBC-M with different membrane protein weight ratios as well as pristine melanin nanoparticles, due to the optimal balance between prolonged blood circulation and homotypic targeting. In addition, in vitro photoacoustic results revealed that Melanin@RBC-M had a photoacoustic signal enhancement with the increase of nanoparticle size (64 → 148 nm) and the photoacoustic amplitudes increased linearly with nanoparticle concentration at the excitation wavelength ranged from 680 nm to 800 nm, which could be used for quantification of Melanin@RBC-M in vivo. Looking forward, coating hybrid membrane onto nanoparticles could add flexibility and controllability in enhancing nanoparticles functionality and offer new opportunities for biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract: Noninvasive near‐infrared (NIR) light responsive therapy is a promising cancer treatment modality; however, some inherent drawbacks of conventional phototherapy heavily restrict its application in clinic. Rather than producing heat or reactive oxygen species in conventional NIR treatment, here a multifunctional yolk–shell nanoplatform is proposed that is able to generate microbubbles to destruct cancer cells upon NIR laser irradiation. Besides, the therapeutic effect is highly improved through the coalition of small interfering RNA (siRNA), which is codelivered by the nanoplatform. In vitro experiments demonstrate that siRNA significantly inhibits expression of protective proteins and reduces the tolerance of cancer cells to bubble‐induced environmental damage. In this way, higher cytotoxicity is achieved by utilizing the yolk–shell nanoparticles than treated with the same nanoparticles missing siRNA under NIR laser irradiation. After surface modification with polyethylene glycol and transferrin, the yolk–shell nanoparticles can target tumors selectively, as demonstrated from the photoacoustic and ultrasonic imaging in vivo. The yolk–shell nanoplatform shows outstanding tumor regression with minimal side effects under NIR laser irradiation. Therefore, the multifunctional nanoparticles that combining bubble‐induced mechanical effect with RNA interference are expected to be an effective NIR light responsive oncotherapy. [ABSTRACT FROM AUTHOR]

In this study, we reported a strategy to improve delivery efficiency of a long-circulation biomimetic photothermal nanoagent for enhanced photothermal therapy through selectively dilating tumor vasculature. By using a simply nanocoating technology, a biomimetic layer of natural red blood cell (RBC) membranes was camouflaged on the surface of photothermal polypyrrole nanoparticles (PPy@RBC NPs). The erythrocyte-mimicking PPy NPs inherited the immune evasion ability from natural RBC resulting in superior prolonged blood retention time. Additionally, excellent photothermal and photoacoustic imaging functionalities were all retained attributing to PPy NPs cores. To further improve the photothermal outcome, the endothelin A (ET A ) receptor antagonist BQ123 was jointly employed to regulate tumor microenvironment. The BQ123 could induce tumor vascular relaxation and increase blood flow perfusion through modulating an ET-1/ET A transduction pathway and blocking the ET A receptor, whereas the vessel perfusion of normal tissues was not altered. Through our well-designed tactic, the concentration of biomimetic PPy NPs in tumor site was significantly improved when administered systematically. The study documented that the antitumor efficiency of biomimetic PPy NPs combined with specific antagonist BQ123 was particularly prominent and was superior to biomimetic PPy NPs ( P < 0.05) and PEGylated PPy NPs with BQ123 ( P < 0.01), showing that the greatly enhanced photothermal treatment could be achieved with low-dose administration of photothermal agents. Our findings would provide a promising procedure for other similar enhanced photothermal treatment by blocking ET A receptor to dramatically increase the delivery of biomimetic photothermal nanomaterials. [ABSTRACT FROM AUTHOR]

Photothermal therapy (PTT) has represented a promising noninvasive approach for cancer treatment in recent years. However, there still remain challenges in developing non-toxic and biodegradable biomaterials with high photothermal efficiency in vivo . Herein, we explored natural melanin nanoparticles extracted from living cuttlefish as effective photothermal agents and developed red blood cell (RBC) membrane-camouflaged melanin (Melanin@RBC) nanoparticles as a platform for in vivo antitumor PTT. The as-obtained natural melanin nanoparticles demonstrated strong absorption at NIR region, higher photothermal conversion efficiency (∼40%) than synthesized melanin-like polydopamine nanoparticles (∼29%), as well as favorable biocompatibility and biodegradability. It was shown that RBC membrane coating on melanin nanoparticles retained their excellent photothermal property, enhanced their blood retention and effectively improved their accumulation at tumor sites. With the guidance of their inherited photoacoustic imaging capability, optimal accumulation of Melanin@RBC at tumors was achieved around 4 h post intravenous injection. Upon irradiation by an 808-nm laser, the developed Melanin@RBC nanoparticles exhibited significantly higher PTT efficacy than that of bare melanin nanoparticles in A549 tumor-bearing mice. Given that both melanin nanoparticles and RBC membrane are native biomaterials, the developed Melanin@RBC platform could have great potential in clinics for anticancer PTT. [ABSTRACT FROM AUTHOR]

An NIR-II light-controlled CO nanogenerator based on an NIR-II-photothermal palladium nanosheet core and a porphyrin-palladium metal–organic framework (Pd-MOF) shell capable of coordinating/loading large amounts of CO with single-atom Pd was described for photoacoustic imaging guided photothermal/CO-combined therapy. The produced CO molecules efficiently increased PTT by downregulating Hsp protein expression and subsequently sensitizing cancer cells to heat, which demonstrated high therapeutic efficacy and may provide a new strategy for cancer theranostics. [Display omitted] • Fabricated a NIR-II light-controlled CO nanogenerator. • CO enhanced cancer photothermal therapy by downregulating ATP and Hsp. • Photoacoustic imaging guided photothermal/CO-combined therapy. Carbon monoxide (CO) has received substantial attention for its many beneficial functions in multiple major diseases. However, precise delivery and controllable release of CO are crucial for CO therapy in cancer but remain technically challenging. Herein, an NIR-II light-controlled CO nanogenerator is described as a new cancer photo-theranostic (Pd@PdCO-MOF) via photoacoustic imaging guided photothermal/CO-combined therapy. This nanogenerator is based on an NIR-II-photothermal palladium nanosheet core and a porphyrin-palladium metal–organic framework (Pd-MOF) shell, which can coordinate/load large amounts of CO with single-atom palladium. Meanwhile, the obtained photo-theranostic exhibited excellent release of CO on demand after NIR-II photoactivation. The produced CO molecules successfully increased the sensitivity of cancer cell to photothermal therapy (PTT). Mechanistically, the CO-assisted PTT efficiently inhibited cancer development by decreasing the intracellular ATP levels, downregulating heat shock protein expression, increasing the expression of cytochrome C , and subsequently activating the apoptosis pathway. Guided by photoacoustic imaging, the obtained Pd@PdCO-MOF nanoplatform demonstrated high therapeutic efficacy in vitro and in vivo through the photothermal-CO combination therapy, which may provide a new strategy for cancer theranostics. [ABSTRACT FROM AUTHOR]

The potential therapeutic implications of nitric oxide (NO) for diverse diseases have been under consideration for years; however, the development of precisely controllable NO generation system with potential for clinical application has remained elusive. Herein, intelligent near-infrared (NIR) laser-triggered NO nanogenerators for the treatment of multidrug-resistant (MDR) cancer are fabricated by integrating photothermal agents and heat-sensitive NO donors into a single nanoparticle. Such nanogenerators can absorb 808 nm NIR photons and convert them into ample heat to trigger NO release. The generated NO molecules are demonstrated to successfully achieve multidrug-resistance reversal by inhibiting the expression of P-glycol protein. Consequently, the intracellular accumulation of doxorubicin is effectively increased, resulting in high toxicity to MDR cancer cells in vitro. By virtue of surface modification with targeting ligands, these nanoparticles are able to selectively accumulate in tumor tissue. The therapeutic effects of the nanogenerators are validated in a humanized MDR cancer model. The in vivo experiment indicates that the nanoparticles possess excellent tumor suppression functionality with few side effects upon NIR laser exposure. Therefore, this novel photothermal conversion-based NO-releasing platform is expected to be a potential alternative to clinical MDR cancer treatment and may provide insights with regard to other NO-relevant medical treatments. [ABSTRACT FROM AUTHOR]

Along with intrinsic magnetic resonance imaging (MRI) advantages, iron oxide nanomaterials capable of photothermal conversion have been reported very recently and have again raised great interest in their designs among biomedical researchers. However, like other inorganic nanomaterials, high macrophage uptake, short blood retention time and unfavorable biodistributions have strongly hampered their applications in vivo . To solve these problems, a rational design of red blood cell (RBC) membrane camouflaged iron oxide magnetic clusters (MNC@RBCs) is presented in this paper. Our data show that by simply introducing an “ultra-stealth” biomimetic coating to iron oxide magnetic nanoclusters (MNCs), MNC@RBCs maintain the imaging and photothermal functionalities inherited from MNCs cores while achieving much lower nonspecific macrophage uptake and dramatically altered fate in vivo . MNC@RBCs with superior prolonged blood retention time, preferred high tumor accumulation and relatively lowered liver biodistribution are demonstrated when injected intravenously in mice, leading to greatly enhanced photothermal therapeutic efficacy by a single treatment without further magnetic force manipulation. Our study illustrates a well prepared integration of MNCs and RBCs, exploiting advantages of both functionalities within a single unit and suggests a promising future for iron-based nanomaterials application in vivo . [ABSTRACT FROM AUTHOR]

The development of cancer photothermal therapies, many of which rely on photothermal agents, has received significant attention in recent years. In this work, various ligands-stabilized magnetite (Fe3O4) particles are fabricated and utilized as a photothermal agents for in vivo tumor-imaging-guided photothermal therapy. Fe3O4 particles stabilized by macromolecular ligands as, e.g. polyethylene glycol (PEG), exhibit a superior and more stable photothermal effect compared to Fe3O4 particles stabilized by small molecules like citrate, due to their stronger ability of antioxidation. In addition, the photothermal effect of Fe3O4 particles is revealed to increase with size, which is attributed to the redshift of Vis-NIR spectra. Fe3O4 particles injected intravenously into mice can be accumulated in the tumor by the application of an external magnetic field, as revealed by magnetic resonance imaging. In vivo photothermal therapy test of PEG-stabilized Fe3O4 further achieves better tumor ablation effect. Overall, this study demonstrates efficient imaging-guided photothermal therapy of cancer that is based on Fe3O4 particles of optimized size and with optimized ligands. It is expected that the ligand-directed and size-dependent photothermal effect will provide more approaches in the design of novel materials. [ABSTRACT FROM AUTHOR]

The strategy to efficiently deliver antitumor drugs via nanocarriers to targeted tumor sites and achieve controllable drug release is attracting great research interest in cancer therapy. In this study, a novel type of disulfide-bonded poly(vinylcaprolactam) (PVCL)-based nanogels with tunable volume phase transition temperature and excellent redox-labile property are prepared. The nanogels are hydrophilic and swell at 37 °C, whereas under hyperthermia (e.g., 41 °C), the nanogels undergo sharp hydrophilic/hydrophobic transition and volume collapse, which enhances the cellular uptake and drug release. The incorporation of disulfide bond linkers endows the nanogels with an excellent disassembly property in reducing environments, which greatly facilitates drug release in tumor cells. Nanogels loaded with doxorubicin (DOX) (DOX-NGs) (DOX-NGs) are stable in physiological conditions with low drug leakage (15% in 48 h), while burst release of DOX (92% in 12 h) can be achieved in the presence of 10 × 10−3 m glutathione and under hyperthermia. The DOX-NGs possess improved cell killing efficiency under hyperthermia (IC50 decreased from 1.58 μg mL−1 under normothermia to 0.5 μg mL−1). Further, the DOX-NGs show a pronounced tumor inhibition rate of 46.6% compared with free DOX, demonstrating that this new dual-responsive nanogels have great potential as drug delivery carriers for cancer therapy in vivo. [ABSTRACT FROM AUTHOR]

A strategy is presented to control the disassembly of nanogels using near‐infrared light. Novel diselenide‐cross‐linked nanogels with a newly synthesized diselenide cross‐linker are prepared. Indocyanine green is incorporated into nanogels to trigger the cleavage of diselenide bond through generating reactive oxygen species. The appropriate control of illumination allows for on‐demand degradation of nanogels and controlled drug release. [ABSTRACT FROM AUTHOR]

Multifunctional nanoparticles for selectively targeting tumor cells and effectively delivering multiple drugs are urgently needed in cancer therapy. Here, a dual-drug delivery system is prepared, based on functionalized hollow mesoporous silica nanoparticles (HMSNs). Doxorubicin (DOX) hydrochloride is loaded into the hollow core, and dichloro(1,2-diaminocyclohexane)platinum (II) (DACHPt) is stored in the pores of the shell by the coordination interaction with the carboxyl groups modified on the pore walls, which also serves as barriers to control the DOX release. Detailed studies in vitro indicate that the DACHPt release is triggered by Cl− through the cleavage of the coordination interaction, and the DOX release depends on the release rate of DACHPt and the environmental pH value. The surface of the mechanized nanoparticles is also modified by transferrin (Tf) to achieve the tumor specificity. Compared with individual drug delivery systems, the dual-drug delivery system shows synergistic efficacy on the cell cytotoxicity (combination index = 0.30), resulting in improved tumor cell killing. The present dual-drug delivery system provides a promising strategy to develop controlled and targeted combination therapies for efficient cancer treatment. [ABSTRACT FROM AUTHOR]

Abstract: As a promising non-viral gene vector, cationic polyamidoamine (PAMAM) dendrimer could form complexes with negative charged DNA to mediate efficient gene delivery in vitro and in vivo. However, complicated synthesis technology and potential cytotoxicity limited their application in clinical translational researches. Hyperbranched polyamidoamine (h-PAMAM), which could be synthesized by a simpler one-pot method, has similar properties with PAMAM, and PEGylation modification of h-PAMAM has been used to reduce cytotoxicity. Here we prepared gene delivery system with h-PAMAM and h-PAMAM derivative h-PAMAM-g-PEG, respectively and found that the viability of cells with h-PAMAM-g-PEG was quite higher in comparison with cells with unmodified h-PAMAM. However, gene delivery efficiency was lower with h-PAMAM-g-PEG. Then we used mixture composed of h-PAMAM and h-PAMAM-g-PEG and such composition was designed to reduce cytotoxicity while maintaining high transfection efficiency. Our results indicated that this mixture system of h-PAMAM and h-PAMAM-g-PEG achieved higher transfection efficiency and lower cytotoxicity compared with h-PAMAM-only system. [Copyright &y& Elsevier]