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Highly hydrophilic and biocompatible nanocarriers based on polysaccharide hydrogels (nanohydrogels, NHs) were shown to be promising systems for drug delivery applications. Following the idea of these emerging drug carriers, the aim of the present work was to develop self-assembled hydrogel nanoparticles based on amphiphilic derivatives of hyaluronic acid (HA) and riboflavin (Rfv), synthesized by “click” Copper(I)-catalyzed Azide-Alkyne Cycloaddition (CuAAC) reaction. The obtained amphiphilic product (HA- c -Rfv) was able to form nanohydrogels in aqueous environments, in particular by applying an innovative autoclave-based method. HA of different molecular weights (M w ) and degrees of substitution (DS) were prepared and the effect of these parameters on the NHs formation was assessed. The derivative HA 220 - c -Rfv 40/40 was chosen as the most interesting system, capable to form NHs in the range of 150–200 nm and with a negative ζ-potential. NHs were very stable in water solutions and, by adding dextrose as cryoprotectant, it was also possible to freeze-dry the NHs formulation. The developed system is proposed for the delivery of hydrophobic drugs; for this purpose, dexamethasone, piroxicam and paclitaxel were used as model drugs; these molecules were loaded into NHs with high efficiency by film-hydration technique. Furthermore, a HA- c -Rfv derivative bearing an excess of propargylic portions was capable to react with other N 3 -derivatized molecules, opening the route to a wide spectrum of functionalization opportunities: in this direction, PEG-N 3 has been tested as a model molecule for the preparation of PEGylated NHs. [ABSTRACT FROM AUTHOR]

ABSTRACT Hydrophobins are amphiphilic fungal proteins endowed with peculiar characteristics, such as a high surface activity and an interface triggered self-assembly. Several applications of these proteins have been proposed in the food, cosmetics and biomedical fields. Moreover, their use as proteinaceous coatings can be effective for materials and nanomaterials applications. The discovery of novel hydrophobins with diverse properties may be advantageous from both the scientific and industrial points of view. Stressful environmental conditions of fungal growth may induce the production of proteins with peculiar features. Two Class I hydrophobins from fungi isolated from marine environment have been recently purified. Herein, their propensity to aggregate forming nanometric fibrillar structures has been compared, using different techniques, such as circular dichroism, dynamic light scattering and Thioflavin T fluorescence assay. Furthermore, TEM and AFM images indicate that the interaction of these proteins with specific surfaces, are crucial in the formation of amyloid fibrils and in the assembly morphologies. These self-assembling proteins show promising properties as bio-coating for different materials via a green process. Biotechnol. Bioeng. 2017;114: 2173-2186. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The emergence of bacterial antibiotic resistances is a serious concern in human and animal health. In this context, naturally occurring cationic antimicrobial peptides (AMPs) might play a main role in a next generation of drugs against bacterial infections. Taking an innovative approach to design self-organizing functional proteins, we have generated here protein-only nanoparticles with intrinsic AMP microbicide activity. Using a recombinant version of the GWH1 antimicrobial peptide as building block, these materials show a wide antibacterial activity spectrum in absence of detectable toxicity on mammalian cells. The GWH1-based nanoparticles combine clinically appealing properties of nanoscale materials with full biocompatibility, structural and functional plasticity and biological efficacy exhibited by proteins. Because of the largely implemented biological fabrication of recombinant protein drugs, the protein-based platform presented here represents a novel and scalable strategy in antimicrobial drug design, that by solving some of the limitations of AMPs offers a promising alternative to conventional antibiotics. Statement of Significance The low molecular weight antimicrobial peptide GWH1 has been engineered to oligomerize as self-assembling protein-only nanoparticles of around 50 nm. In this form, the peptide exhibits potent and broad antibacterial activities against both Gram-positive and Gram-negative bacteria, without any harmful effect over mammalian cells. As a solid proof-of-concept, this finding strongly supports the design and biofabrication of nanoscale antimicrobial materials with in-built functionalities. The protein-based homogeneous composition offer advantages over alternative materials explored as antimicrobial agents, regarding biocompatibility, biodegradability and environmental suitability. Beyond the described prototype, this transversal engineering concept has wide applicability in the design of novel nanomedicines for advanced treatments of bacterial infections. [ABSTRACT FROM AUTHOR]

We report the preparation and characterization of aqueous Pickering foams using bio-particles constituted by lactic acid bacteria surface modified by oppositely charged milk proteins. Cell surface modification was shown by zeta potential measurements. Foams stabilized by bacterial Pickering bio-particles showed improved stability compared to purely milk protein stabilized foams. The stability of foams increased with the bacterial concentration whereas the foam volume (foamability) decreased. On the other hand, protein concentration was correlated with foamability but not with the foam stability. Optical and fluorescence microscopy revealed organized cell structures around and in between the air bubbles providing for an internal network that effectively stabilizes the foam. Therefore, entirely food grade stable foams can be produced by using modified health promoting bacterial cells and surface active milk proteins. Such Pickering systems can potentially be utilized in bottom up construction of more complex hierarchical food structures and further improve properties such as foam stability. [ABSTRACT FROM AUTHOR]

Magnetic nanofiber has been widely applied in biomedical fields due to its distinctive size, morphology, and properties. We proposed a novel needleless electrospinning method to prepare magnetic nanofibers from the self-assembling "Taylor cones" of poly(vinyl pyrrolidone) (PVP)/Fe3O4 ferrofluid (PFF) under the coincident magnetic and electric fields. The results demonstrated that a static PFF Rosensweig instability with a conical protrusion could be obtained under the magnetic field. The tip of the protrusion emitted an electrospinning jet under the coincident magnetic and electric fields. The needleless electrospinning showed a similar process phenomenon in comparison with conventional electrospinning. The prepared nanofibers were composed of Fe3O4 particles and PVP polymer. The Fe3O4 particles aggregated inside and on the surface of the nanofibers. The nanofibers prepared by needleless electrospinning exhibited similar morphology compared with the conventionally electrospun nanofibers. The nanofibers also exhibited good ferromagnetic and magnetic field responsive properties. [ABSTRACT FROM AUTHOR]

A bi-component nanostructured system composed by a Co dot array embedded in a Ni80Fe20 antidot matrix has been prepared by means of the self-assembling polystyrene nanospheres lithography technique. Reference samples constituted by the sole Co dots or Ni80Fe20 antidots have also been prepared, in order to compare their properties with those of the bi-component material. The coupling between the two ferromagnetic elements has been studied by means of magnetic and magneto-transport measurements. The Ni80Fe20 matrix turned out to affect the vortex nucleation field of the Co dots, which in turn modifies the magneto-resistance behaviour of the system and its spinwave properties. [ABSTRACT FROM AUTHOR]

Herein, we constructed a novel sandwich surface plasmon resonance (SPR) detection assay for sensitive prion disease-associated isoform (PrP Sc ) detection, utilizing bare gold film and apatamer-graphene oxide (AGO). Due to the self-assembling behavior of PrP Sc on gold surface, the non-modified gold surface can be directly used as sensing surface for the quick detection, for the purpose to avoid the interference from the traditional, complex and changeable probe-modified sensing surface. And due to the highly specific affinity of AGO towards PrP Sc , the sandwich type SPR sensor exhibits excellent analytical performance towards the discrimination and quantitation of PrP Sc . A good linear relationship was obtained between SPR responses and the logarithm of PrP Sc concentrations over a range of 0.001–1 ng/mL. The detection sensitivity for PrP Sc was improved by ∼156 orders of AGO compared with SPR direct detection format. Besides, morphological changes of the sensing film surfaces were investigated by high resolution AFM imaging, confirming the capture of PrP Sc molecules and their further specific recognition by AGO. The specificity of the present biosensor was also investigated by PrP C and other regents as controls. By compared with other reported methods, the AGO enhanced sandwich SPR assay was confirmed to be efficient, sensitive, and with wide working range. [ABSTRACT FROM AUTHOR]

Chitosan (CHI) is a versatile biological material that is well known for its hemostatic properties. This preliminary study evaluated several self-assembling hydrophobically modified chitosan (HM-CHI) sponges to determine their efficacy on . Fourier transform infrared (FT-IR) spectroscopy was used to determine the successful graft of dodecyl groups onto the nitrogen atoms of CHI molecules. A platelet aggregation assay revealed that HM-CHI accelerated the platelet aggregation rate. Fluorescence spectroscopy showed that the HM-CHI changed the structure of fibrinogen in blood. Activated partial thromboplastin time, prothrombin time, fibrinogen time, and thromboelastographic assays were used to explore the effect of HM-CHI on the autologous blood coagulation pathway. Finally, a hemostatic sponge was made with HM-CHI and freeze-dried zeolite composite film and was applied to the rat femoral artery model. A time of 86 ± 5 sec was achieved, which was significantly better than the one composed with pure CHI. The experimental results of the HM-CHI hemostatic materials are inspiring and will encourage the research and development of such materials. HM-CHI may be a strong candidate as a safe and effective hemostatic material. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Breast cancer has become the second leading cause of cancer-related mortality in female wherein more than 90% of breast cancer-related death results from cancer metastasis to distant organs at advanced stage. The purpose of this study is to develop biodegradable nanoparticles composed of natural polypeptides and calcium phosphate (CaP) with sequential pH-responsivity to tumor microenvironments for active targeted drug delivery. Two different amphiphilic copolymers, poly(ethylene glycol) 3400 -aconityl linkage-poly( l -glutamic acid) 15 -poly( l -histidine) 10 -poly( l -leucine) 10 and LyP1-poly(ethylene glycol) 1100 -poly( l -glutamic acid) 15 -poly( l -histidine) 10 -poly( l -leucine) 10 , were exploited to self-assemble into micelles in aqueous phase. The bio-stable nanoparticles provide three distinct functional domains: the anionic PGlu shell for CaP mineralization, the protonation of PHis segment for facilitating anticancer drug release at target site, and the hydrophobic core of PLeu for encapsulation of anticancer drugs. Furthermore, the hydrated PEG outer corona is used for prolonging circulation time, while the active targeting ligand, LyP-1, is served to bind to breast cancer cells and lymphatic endothelial cells in tumor for inhibiting metastasis. Mineralized DOX-loaded nanoparticles (M-DOX NPs) efficiently prevent the drug leakage at physiological pH value and facilitate the encapsulated drug release at acidic condition when compared to DOX-loaded nanoparticles (DOX NPs). M-DOX NPs with LyP-1 targeting ligand effectively accumulated in MDA-MB-231 breast cancer cells. The inhibition effect on cell proliferation also enhances with time, illustrating the prominent anti-tumor efficacy. Moreover, the in vitro metastatic inhibition model shows the profound inhibition effect of inhibitory nanoparticles. In brief, this self-assembling peptide-based drug delivery nanocarrier with multifunctionality and programmable pH-sensitivity is of great promise and potential for anti-cancer therapy. Statement of Significance This tailored-design polypeptide-based nanoparticles with self-assembling and programmable stimulus-responsive properties enable to 1) have stable pH in physiological value with a low level of drug loss and effectively release the encapsulated drug with pH variations according to the tumor microenvironment, 2) enhance targeting ability to hard-to-treat breast cancer cells and activate endothelial cells (tumor region), 3) significantly inhibit the growth and prevent from malignant metastasis of cancer cells in consonance with promising anti-tumor efficacy, and 4) make tumors stick to localized position so that these confined solid tumors can be more accessible by different treatment modalities. This work contributes to designing a programmable pH-responsive drug delivery system based on the tailor-designed polypeptides. [ABSTRACT FROM AUTHOR]

Lignin can protect plants from sunshine radiation, thus making its development as a natural macromolecular sunscreen for human skin protection against UV radiation attractive. In this work, lignin colloidal spheres with different sizes and structures are prepared by self-assembly and then blended with pure skin cream to develop lignin-based sunscreens. Results show that the creams with lignin colloidal spheres added to it as actives have better sunscreen performance than those blended with original lignin. The sun protection factor (SPF) value of the sunscreens decreases with the size of lignin colloidal spheres. Phenolic hydroxyl groups play an important role during the lignin’s sun blocking process. When lignin is acetylated, SPF values of the sunscreens decrease dramatically, but will recover to a certain degree when acetylated lignin forms uniform colloidal spheres. Therefore, organosolv lignin (OL) with more phenolic hydroxyl groups is applied. The SPF value of the sunscreen containing 10 wt% OL colloidal spheres with the size of about 50 nm reaches 15.03. The SPF value of sunscreen containing 10 wt% middle size OL colloidal spheres can be boosted from 10.69 to 47.71 by adding 2 wt% UVA and 2 wt% UVB chemical sunscreens. [ABSTRACT FROM AUTHOR]

In 2013 a novel self-assembly strategy for polypeptide nanostructure design which could lead to significant developments in biotechnology was presented in Gradišar et al. (Nat Chem Bio 9:362-366, 2013). It was since observed that a polyhedron P can be realized by interlocking pairs of polypeptide chains if its corresponding graph G( P) admits a strong trace. It was since also demonstrated that a similar strategy can also be expanded to self-assembly of designed DNA (Kočar, Nat commun 7:1-8, 2016). In this direction, in the present paper we characterize graphs which admit closed walk which traverses every edge exactly once in each direction and for every vertex v, there is no subset N of its neighbors, with $$1 \le |N| \le d$$ , such that every time the walk enters v from N, it also exits to a vertex in N. This extends Thomassen's characterization (Thomassen, J Combin Theory Ser B 50:198-207, 1990) for the case $$d = 1$$ . [ABSTRACT FROM AUTHOR]

Effectively, two-dimensional (2D) closed films exhibiting in-plane orientational ordering (ordered shells) might be instrumental for the realization of scaled crystals. In them, ordered shells are expected to play the role of atoms. Furthermore, topological defects (TDs) within them would determine their valence. Namely, bonding among shells within an isotropic liquid matrix could be established via appropriate nano-binders (i.e., linkers) which tend to be attached to the cores of TDs exploiting the defect core replacement mechanism. Consequently, by varying configurations of TDs one could nucleate growth of scaled crystals displaying different symmetries. For this purpose, it is of interest to develop a simple and robust mechanism via which one could control the position and number of TDs in such atoms. In this paper, we use a minimal mesoscopic model, where variational parameters are the 2D curvature tensor and the 2D orientational tensor order parameter. We demonstrate numerically the efficiency of the effective topological defect cancellation mechanism to predict positional assembling of TDs in ordered films characterized by spatially nonhomogeneous Gaussian curvature. Furthermore, we show how one could efficiently switch among qualitatively different structures by using a relative volume v of ordered shells, which represents a relatively simple naturally accessible control parameter. [ABSTRACT FROM AUTHOR]

It is a huge challenge to synthesize high luminescent performance of graphene oxide-rare earth hybrid materials, due to the strong quenching effect of graphene oxide. Herein we reveal a novel graphene oxide/rare-earth complexes hybrid materials that the Eu 3+ -2-thenoyltrifluoroacetone (TTA)-pyromellitic acids (PMA) were deposited on the surface of graphene oxide sheets (GOSs) via noncovalent approach between GOSs and PMA. This materials exhibit stronger luminescence intensity, longer decay lifetime and better thermal stability than pure Eu 3+ complexes. It is confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and luminescent data. Moreover, we observed PMA plays a significant role in improving the luminescence intensity and prolonging the decay lifetime of hybrid materials. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride nanosheets (g-CN NS) are an important material with many promising practical applications. However, construction of g-CN NS self-assembled structures with three dimensions (3D) has never been realized. Here, we prepared a self-assembled g-CN NS microgel (SGM) via hydrothermal treatment of g-CN NS in the presence of Ca. The size and microstructure of SGM can be controlled by the concentration of Ca. The obtained SGM also exhibits a temperature response, improved optical properties and high photocatalytic activity. [ABSTRACT FROM AUTHOR]

Functionalization of thin and stretchable polymer layers by nano- and micro-patterning of nanoparticles is a very promising field of research that can lead to many different applications in biology and nanotechnology. In this work, we present a new procedure to self-assemble semiconductor quantum dots (QDs) nanoparticles by a simple fabrication process on a freestanding flexible PolyDiMethylSiloxane (PDMS) membrane. We used a Periodically Poled Lithium Niobate (PPLN) crystal to imprint a micrometrical pattern on the PDMS membrane that drives the QDs self-structuring on its surface. This process allows patterning QDs with different wavelength emissions in a single step in order to tune the overall emission spectrum of the composite, tuning the QDs mixing ratio. [ABSTRACT FROM AUTHOR]

It was found that the alternation of the melting points of 3 n -crown- n retains its amplitude within a large range of the number of oxygen atoms ( n = 4–8) in the crown's ring. This behavior is different from that observed for the compounds having n -alkyl chain, where the odd-even effect gradually disappears with increasing number of carbon atoms in the chain. So, the molecular structures of crown ethers containing in their rings even or odd number of oxygen atoms essentially differ from each other and the differences do not disappear when the ring increases. On the basis of temperature behavior of the increment of orientational entropy it was found that in liquid 12-crown-4 and 15-crown-5, the molecules self-organize into entities where the molecules are arranged in a head-to-tail way, while the molecules of 18-crown-6 are behaving quite differently: self-assemblies with antiparallel orientation of the molecular dipoles are predominant. [ABSTRACT FROM AUTHOR]

Recently various drug candidates with excellent anticancer potency have been demonstrated, whereas their clinical application largely suffers from several limitations especially poor solubility. Ursolic acid (UA) as one of ubiquitous pentacyclic triterpenes in plant kingdom exhibited versatile antiproliferative effects in various cancer cell lines. However, the unfavorable pharmaceutical properties became the main obstacle for its clinical development. With the aim of development of novel derivatives with enhanced potency, a series of diversified UA amphiphiles have been designed, synthesized, and pharmacologically evaluated. Amphiphile 10 ( FZU-03,010 ) with significant improved antiproliferative effect can self-assemble into stable nanoparticles in water, which may serve as a promising candidate for further development. [ABSTRACT FROM AUTHOR]

Glycerol carbonate is one of the most potentially multifunction glycerol-derived compounds. Glycerol is an important by-product of the oleochemical industry. The oligomerization of glycerol carbonate, assisted by the glycerol, results in the production of polyhydroxylated oligomers rich in linear carbonate groups. The polar moieties of these oligomers (M w < 1000 Da) were supplied by glycerol and glycerol carbonate rather than ethylene oxide as in most commercial surfactants. The insertion of linear carbonate groups into the glycerol-based skeleton rendered the oligomers amphiphilic, resulting in a decrease in air/water surface tension to 57 mN/m. We improved the physical and chemical properties of the oligomers, by altering the type of acylation reaction and the nature of the acyl donor. The polar head is constituted of homo-oligomers and hetero-oligomers. Homo-oligomers are oligoglycerol and/or oligocarbonate, hetero-oligomers are oligo(glycerol-glycerol carbonate). Coprah oligoesters had the best surfactant properties (CMC < 1 mg/mL, π cmc < 30 mN/m), outperforming molecules of fossil origin, such as ethylene glycol monododecyl ether, glycol ethers and fatty acid esters of sorbitan polyethoxylates. The self-assembling properties of oligocarbonate esters were highlighted by their ability to stabilize inverse and multiple emulsions. The oligo-(glycerol carbonate-glycerol ether) with relatively low molecular weights showed properties of relatively high-molecular weight molecules, and constitute a viable “green” alternative to ethoxylated surfactants. [ABSTRACT FROM AUTHOR]

Macromolecular co-assemblies built up in aqueous solutions, by using a linear polypeptide, poly(aspartic acid) (PAS), and a globular protein, bovine serum albumin (BSA), have been studied. The main interest was to identify the optimum conditions for an interpenetrated complex formation in order to design materials suitable for biomedical applications, such as drug delivery systems. BSA surface possesses several amino- and carboxylic groups available for covalent modification, and/or bioactive substances attachment. In the present study, mixtures between PAS and BSA were investigated at 37 °C in dilute aqueous solution by viscometry, dynamic light scattering and zeta potential determination, as well as in solid state by AFM microscopy and dielectric spectroscopy. The experimental data have shown that the interpolymer complex formation occurs for a PAS/BSA molar ratio around 0.541. [ABSTRACT FROM AUTHOR]

Telechelic PEG-polymers end-capped by diphenylalanine (FF) motives and containing a DOTA-Gd complex, bound on a lysine side chain at the centre of peptide moiety, are studied for their assembling properties and for the relaxometric behavior. The observed variations in terms of relaxivity are correlated to the assembling properties of the aggregates by using several techniques: fluorescence, Circular Dichroism (CD) and Fourier Transform Infrared (FTIR) for aggregation tendency and secondary structure determination; Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM) for morphological definition. Self-aggregation in water solution of the peptide conjugates, due to interaction of the phenylalanine frameworks, starts at concentration around 1 mg/ml with a first evidence of the coexistence of fibrillary networks and hydrogels at 10 mg/ml. Definitive presence of well-structured fibrillary networks, dominated by an antiparallel β-sheet arrangement, occurs at 50 mg/ml. At the latter concentration relaxivity values measured at 20 MHz and 298 K, are around 11 mM−1 s−1, in line with a possible use of the these aggregates as MRI contrast agents. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The effects of the replacement of einkorn flour on pasta proteins aggregation were studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis and size exclusion high performance chromatography. Pasta was produced replacing durum wheat semolina with an increasing amount of einkorn flour (30, 50 and 100%). The polymeric protein structure of flours and related pasta and pasta mixture was determined by protein subunits composition and size of polymeric proteins. The unextractability of polymeric protein was related to the unextractable protein fraction and to the determination of –SH/-SS groups. Durum wheat semolina and einkorn flours increased their unextractable and polymeric fractions during pasta processing. The unexpected results derived from the areas of unextractable fractions and total and large unextractable polymeric fractions of 70/30 semolina/einkorn pasta mixture that were lower than those of 50/50 semolina/einkorn pasta mixture. Although the semolina flour contained more gluten proteins than einkorn flour, a higher aggregation was registered for 50/50 semolina/einkorn flour pasta. These results suggested that a different assessment of gluten network occurred in pasta mixture and it was regulated by a self-assembling machine influenced by nature of HMW-GS. The 50/50 semolina/einkorn pasta mixture determined a supramolecular structure in the developing of its network architecture. [ABSTRACT FROM AUTHOR]

Electrochemical bacteria Shewanella oneidensis MR-4 (MR-4) was used to biologically generate cadmium sulfide (bio-CdS) nanocrystals and construct a self-assembled intimately coupled photocatalysis-biodegradation system (SA-ICPB) to remove cadmium (Cd) and tetracycline hydrochloride (TCH) from wastewater. The characterization using EDS, TEM, XRD, XPS, and UV–vis confirmed the successful CdS bio-synthesis and its visible-light response capacity (520 nm). 98.4% of Cd2+ (2 mM) was removed during bio-CdS generation within 30 min. The electrochemical analysis confirmed the photoelectric response capability of the bio-CdS as well as its photocatalytic efficiency. Under visible light, SA-ICPB entirely eliminated TCH (30 mg/L). In 2 h, 87.2% and 43.0% of TCH were removed separately with and without oxygen. 55.7% more chemical oxygen demand (COD) was removed with oxygen participation, indicating the degradation intermediates elimination by SA-ICPB required oxygen participation. Biodegradation dominated the process under aerobic circumstances. Electron paramagnetic resonance analysis indicated that h+ and ·O 2 - played a decisive role in photocatalytic degradation. Mass spectrometry analysis proved that TCH was dehydrated, dealkylated, and ring-opened before mineralizing. In conclusion, MR-4 can spontaneously generate SA-ICPB and rapidly-deeply eliminate antibiotics by coupling photocatalytic and microbial degradation. Such an approach was efficient for the deep degradation of persistent organic pollutants with antimicrobial properties. [Display omitted] • S. oneidensis bio-recover Cd as CdS for visible light photocatalytic degradation. • Self-assembled intimately coupled photocatalysis-biodegradation system (SA-ICPB). • Photocatalysis and biodegradation efficiency is enhanced in the bio-hybrid system. • SA-ICPB prefers aerobic conditions and works differently anaerobically. [ABSTRACT FROM AUTHOR]

The supramolecular self-assembling hydrogel film was designed using a polymer blend of chitosan and partially hydrolyzed polyacrylamide (CS/PHPA), which was constructed with a controllable sol-gel transition, using a green one-pot external salt-assisted sol-gel transition and aqueous solution casting method that does not employ any toxic chemical crosslinking agents. The structure of hydrogel film was confirmed by zeta potential, FT-IR, XRD, SEM, EDX, and TG / DTGA. The swelling properties of gels were well investigated and the results revealed a rapid swelling rate. Notably, the composite hydrogel film exhibited remarkable thermo- and pH-induced sol-gel transitions. The zeta potential of supramolecular CS / PHPA hydrogel was −51.5 mV (pH 7.0), which provided a good adsorption performance for the cationic dye methyl blue (MB). The adsorption process obeyed the pseudo-second-order kinetic model and the maximum adsorbed amount for MB was high up to 282 mg / g. The adsorption equilibrium data correlated well with the Langmuir model, suggesting that the MB was removed through the monolayer and physical adsorption mechanism. After five adsorption / desorption cycles using a mixture of (HCl:1-Butanol) as eluent, the dye adsorption efficiency decreased from 96.45 to 79.80%. The possible adsorption mechanism is believed to be the non-covalent interactions (the electrostatic interactions together with hydrogen bonding between the N atom of MB and the H atom of functional groups of the hydrogel. Overall, the "green" gelation process provides a new opportunity for the rational design of self-assembling physical hydrogels as adsorbents for cationic and anionic dye removal. The supramolecular composite hydrogel film was designed using a polymer blend of chitosan and partially hydrolyzed polyacrylamide (CS/PHPA), which was constructed with a controllable sol-gel transition, using a green one-pot external salt-induced sol-gel transition and aqueous solution casting method that does not employ any toxic chemical crosslinking agents. Notably, the composite hydrogel film exhibited remarkable adhesiveness performance as well as thermo- and pH-induced sol-gel transitions. The zeta potential of supramolecular CS / PHPA hydrogel was −51.5 mV (pH 7.0), which provided a good adsorption performance for the cationic dye methyl blue (MB). The adsorption process obeyed the pseudo-second-order kinetic model and the maximum adsorbed amount for MB was high up to 282 mg / g. The adsorption equilibrium data correlated well with the Langmuir model, suggesting that the MB was removed through the monolayer and physical adsorption mechanism. [Display omitted] • A supramolecular self-assembled CS-PHPA composite hydrogel was fabricated. • The non-covalent interactions drove the supramolecular self-assembly of CS and PHPA. • The CS / PHPA self-assembled composite hydrogel film possessed multi-functionalities. • MB adsorption data followed Langmuir isotherm and pseudo-second-order kinetics model. • Thermodynamic study indicated the adsorption process was exothermic and spontaneous. [ABSTRACT FROM AUTHOR]

Among bio-inspired protein materials, secretory protein microparticles are of clinical interest as self-contained, slow protein delivery platforms that mimic secretory granules of the human endocrine system, in which the protein is both the drug and the scaffold. Upon subcutaneous injection, their progressive disintegration results in the sustained release of the building block polypeptides, which reach the bloodstream for systemic distribution and subsequent biological effects. Such entities are easily fabricated in vitro by Zn-assisted cross-molecular coordination of histidine residues. Using cationic Zn for the assembly of selected pure protein species and in the absence of any heterologous holding material, these granules are expected to be nontoxic and therefore adequate for different clinical uses. However, such presumed biosafety has not been so far confirmed and the potential protein dosage threshold not probed yet. By selecting the receptor binding domain (RBD) from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein as a model protein and using a mouse lab model, we have explored the toxicity of RBD-made secretory granules at increasing doses up to ∼100 mg/kg of animal weight. By monitoring body weight and biochemical blood markers and through the histological scrutiny of main tissues and organs, we have not observed systemic toxicity. Otherwise, the bioavailability of the material was demonstrated by the induction of specific antibody responses. The presented data confirm the intrinsic biosafety of artificial secretory granules made by recombinant proteins and prompt their further clinical development as self-contained and dynamic protein reservoirs.

A novel voltammetric sensor based on a self-assembled composite formed by native DNA and electropolymerized N-phenyl-3-(phenylimino)-3H-phenothiazin-7-amine has been developed and applied for sensitive determination of doxorubicin, an anthracycline drug applied for cancer therapy. For this purpose, a monomeric phenothiazine derivative has been deposited on the glassy carbon electrode from the 0.4 M H 2 SO 4 -acetone mixture (1:1 v / v ) by multiple potential cycling. The DNA aliquot was either on the electrode modified with electropolymerized film or added to the reaction medium prior to electropolymerization. The DNA entrapment and its influence on the redox behavior of the underlying layer were studied by scanning electron microscopy and electrochemical impedance spectroscopy. The DNA-doxorubicin interactions affected the charge distribution in the surface layer and, hence, altered the redox equilibrium of the polyphenothiazine coating. The voltametric signal was successfully applied for the determination of doxorubicin in the concentration range from 10 pM to 0.2 mM (limit of detection 5 pM). The DNA sensor was tested on spiked artificial plasma samples and two commercial medications (recovery of 90-95%). After further testing on real clinical samples, the electrochemical DNA sensor developed can find application in monitoring drug release and screening new antitumor drugs able to intercalate DNA.

Introduction: In fragment-based drug design, fragment linking is a popular strategy where two fragments binding to different sub-pockets of a target are linked together. This attractive method remains challenging especially due to the design of ideal linkers., Areas Covered: The authors review the types of linkers and chemical reactions commonly used to the synthesis of linkers, including those utilized in protein-templated fragment self-assembly, where fragments are directly linked in the presence of the protein. Finally, they detail computational workflows and software including generative models that have been developed for fragment linking., Expert Opinion: The authors believe that fragment linking offers key advantages for compound design, particularly for the design of bivalent inhibitors linking two distinct pockets of the same or different subunits. On the other hand, more studies are needed to increase the potential of protein-templated approaches in FBDD. Important computational tools such as structure-based de novo software are emerging to select suitable linkers. Fragment linking will undoubtedly benefit from developments in computational approaches and machine learning models.

Liposomes and other nanoparticles have been widely studied as innovative nanomaterials because of their unique properties. Pyridinium salts, on the basis of 1,4-dihydropyridine (1,4-DHP) core, have gained significant attention due to their self-assembling properties and DNA delivery activity. This study aimed to synthesize and characterize original N -benzyl substituted 1,4-dihydropyridines and evaluate the influence on structure modifications on compound physicochemical and self-assembling properties. Studies of monolayers composed of 1,4-DHP amphiphiles revealed that the mean molecular areas values were dependent on the compound structure. Therefore, the introduction of N -benzyl substituent to the 1,4-DHP ring enlarged the mean molecular area by almost half. All nanoparticle samples obtained by ethanol injection method possessed positive surface charge and average diameter of 395-2570 nm. The structure of the cationic head-group affects the size of the formed nanoparticles. The diameter of lipoplexes formed by 1,4-DHP amphiphiles and mRNA at nitrogen/phosphate (N/P) charge ratios of 1, 2, and 5 were in the range of 139-2959 nm and were related to the structure of compound and N/P charge ratio. The preliminary results indicated that more prospective combination are the lipoplexes formed by pyridinium moieties containing N -unsubstituted 1,4-DHP amphiphile 1 and pyridinium or substituted pyridinium moieties containing N -benzyl 1,4-DHP amphiphiles 5a - c at N/P charge ratio of 5, which would be good candidates for potential application in gene therapy.

We aimed to determine the coacervation properties of high-molecular-weight (HMW) tissue-derived elastin (TDE) and to examine the potential use of TDE particles as a cosmetic biomaterial. TDE solutions were filtered and divided into three fractions (1-3) according to the molecular weight of the elastin. The turbidity of fraction 2, which contained a large portion (58%) of HMW elastin polypeptides (>100 kDa), was measured under several pH values (3.0-11.0) and NaCl concentrations (0-1000 mM) to examine its coacervation ability. HMW TDE exhibited coacervation under the physiological conditions (temperature, pH, and NaCl concentration) of the skin surface. We performed inclusion and release experiments using three model chemicals with different molecular weights and measured the size and zeta potential of the fraction 3 particles to investigate the suitability of HMW elastin polypeptides. Fraction 3, which contained a larger portion (64%) of HMW elastin polypeptides, displayed a strong coacervation property at a phase transition temperature of 19.8 ± 0.1°C. The inclusion ratio of the model chemical Biebrich Scarlet (BS) with a molecular weight of <600 was approximately 92.1 ± 0.7%. The release profiles of BS from the particles linearly increased and reached a plateau after 15 days. Moreover, the average size of the particles with BS was 474.2 ± 24.6 nm. The low-molecular-weight (LMW) elastin peptides have moisturizing and whitening functions for the skin. We concluded that TDE, as a mixture of HMW polypeptides and LMW peptides, can potentially serve as a multifunctional and effective cosmetic biomaterial., (© 2022 European Peptide Society and John Wiley & Sons Ltd.)

Beryllium subphthalocyanines have been recently shown to be suitable candidates for photochemical devices if combined with appropriate donor systems. The ability of beryllium subphthalocyanines to self-assemble is explored for the first time by means of density functional theory calculations. Free dimers of beryllium subphtalocyanine and their corresponding complexes with water and pyridine are computed at the wB97X-D/6-311+G(d,p) level of theory. In contrast with the behavior reported for beryllium phthalocyanines, for beryllium subphtalocyanines, beryllium-aza-nitrogen intermolecular interactions are observed, suggesting that these species are likely to self-assemble. Aggregates of related structures such as beryllium subporphyrazines with axial groups confirm the importance of hydrogen bonds in the stacking. [ABSTRACT FROM AUTHOR]

Nanoscale magnetic materials are the basis of emerging technologies to develop novel magnetoelectronic devices. Self-assembly of polystyrene nanospheres is here used to generate 2D hexagonal dot arrays on Fe50Pd50thin films. This simple technique allows a wide-area patterning of a magnetic thin film. The role of disorder on functional magnetic properties with respect to conventional lithographic techniques is studied. Structural and magnetic characteristics have been investigated in arrays having different geometry (i.e. dot diameters, inter-dot distances and thickness). The interplay among microstructure and magnetization reversal is discussed. Magnetic measurements reveal a vortex domain configuration in all as-prepared films. The original domain structure changes drastically upon thermal annealing performed to promote the transformation of disordered A1 phase into the ordered, tetragonal L10phase. First-order reversal magnetization curves have been measured to rule out the role of magnetic interaction among crystalline phases characterized by different magnetic coercivity. [ABSTRACT FROM AUTHOR]

The purpose of the study was to develop physically cross-linked novel pH-responsive gelatin – Wells–Dawson-type polyoxometalate (POM)-based self-assembled hydrogels using acrylic acid as a pH-responsive monomer. Cross-linking was achieved through electrostatic interactions between the cationic polymer and anionic Wells–Dawson POM [P2W15O56]12−. Ammonium persulfate and sodium hydrogen sulfite were used as initiators. The hydrogels were yellowish in color and exhibited low mechanical strength. Swelling, drug release, and pH sensitivity studies were conducted at pH 1.2 and 7.4. pH-dependent swelling and release of [P2W15O56]12−from the prepared hydrogels were observed, with a maximum at pH 7.4. The hydrogels were characterized by thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy for evaluation of the surface morphology, hydrogel confirmation, and thermal properties. The results obtained confirmed the development of a gelatin–POM-based self-assembled hydrogel. It can be concluded that as a result of successful physical cross linking, the prepared hydrogels possess desired characteristics of a drug delivery system and can hence be used for a controlled delivery of the encapsulated polyanions. . [ABSTRACT FROM AUTHOR]

Pure monoglycerides (GM-Cs) and glycerol carbonate esters (GCE-Cs) are two families of oleochemical molecules composed of a polar part, glycerol for GM-Cs, glycerol carbonate for GCE-Cs, and a fatty acid lipophilic part. From a chemical point of view, GM-Cs include two free oxygen atoms in the hydroxyl functions and one ester function between the fatty acid and the glycerol parts. GCE-Cs contain two blocked oxygen atoms in the cyclic carbonate backbone and three esters functions: two endocyclic in the five-membered cyclic carbonate function, one exocyclic between the fatty acid and glycerol carbonate parts. At the physico-chemical level, GMCs and GCE-Cs are multifunctional molecules with amphiphilic structures: a common hydrophobic chain to the both families and a polar head, glycerol for GMs and glycerol carbonate for GCE-Cs. Physicochemical properties depend on chain lengths, odd or even carbon numbers on the chain, and glyceryl or cyclocarbonic polar heads. The solvo-surfactant character of GM-Cs and overall GCE-Cs were discussed through the measurements of critical micellar concentration (CMC) or critical aggregation concentration (CAC). These surface active glycerol esters/glycerol carbonate esters were classified following their hydrophilic/hydrophobic character correlated to their chain length (LogPoctanol/water = f(atom carbon number)). Differential scanning calorimetry and optical polarized light microscopy allow us to highlight the selfassembling properties of the glycerol carbonate esters alone and in presence of water. We studied by thermal analysis the polymorphic behaviour of GCE-Cs, and the correlation between their melting points versus the chain lengths. Coupling the self-aggregation and crystallization properties, superhydrophilic surfaces were obtained by formulating GM-Cs and GCE-Cs. An efficient durable water-repellent coating of various metallic and polymeric surfaces was allowed. Such surfaces coated by self-assembled fatty acid esters in a stable coagel state present a novel solution for the water-repellent coating of surfaces.

For many applications it is desirable to have nanoparticles positioned on top of a given substrate well separated from each other and arranged in arrays of a certain geometry. For this purpose, a method is introduced combining the bottom-up self-organization of precursor-loaded micelles providing Au nanoparticles (NPs), with top-down electron-beam lithography. As an example, 13 nm Au NPs are arranged in a square array with interparticle distances >1 µm on top of Si substrates. By using these NPs as masks for a subsequent reactive ion etching, the square pattern is transferred into Si as a corresponding array of nanopillars.

Self-assembling block copolymers (poloxamers, PEG/PLA and PEG/PLGA diblock and triblock copolymers, PEG/polycaprolactone, polyether modified poly(Acrylic Acid)) with large solubility difference between hydrophilic and hydrophobic moieties have the property of forming temperature dependent micellar aggregates and, after a further temperature increase, of gellifying due to micelle aggregation or packing. This property enables drugs to be mixed in the sol state at room temperature then the solution can be injected into a target tissue, forming a gel depot in-situ at body temperature with the goal of providing drug release control. The presence of micellar structures that give rise to thermoreversible gels, characterized by low toxicity and mucomimetic properties, makes this delivery system capable of solubilizing water-insoluble or poorly soluble drugs and of protecting labile molecules such as proteins and peptide drugs.

(Arginine-alanine-aspartic acid-alanine)4 ((RADA)4) nanoscaffolds are excellent candidates for use as peptide delivery vehicles: they are relatively easy to synthesize with custom bio-functionality, and assemble in situ to allow a focal point of release. This enables (RADA)4 to be utilized in multiple release strategies by embedding a variety of bioactive molecules in an all-in-one “construct”. One novel strategy focuses on the local, on-demand release of peptides triggered via proteolysis of tethered peptide sequences. However, the spatial-temporal morphology of self-assembling nanoscaffolds may greatly influence the ability of enzymes to both diffuse into as well as actively cleave substrates. Fine structure and its impact on the overall effect on peptide release is poorly understood. In addition, fractal networks observed in nanoscaffolds are linked to the fractal nature of diffusion in these systems. Therefore, matrix morphology and fractal dimension of virgin (RADA)4 and mixtures of (RADA)4 and matrix metalloproteinase 2 (MMP-2) cleavable substrate modified (RADA)4 were characterized over time. Sites of high (glycine-proline-glutamine-glycine+isoleucine-alanine-serine-glutamine (GPQG+IASQ), CP1) and low (glycine-proline-glutamine-glycine+proline-alanine-glycine-glutamine (GPQG+PAGQ), CP2) cleavage activity were chosen. Fine structure was visualized using transmission electron microscopy. After 2 h of incubation, nanofiber networks showed an established fractal nature; however, nanofibers continued to bundle in all cases as incubation times increased. It was observed that despite extensive nanofiber bundling after 24 h of incubation time, the CP1 and CP2 nanoscaffolds were susceptible to MMP-2 cleavage. The properties of these engineered nanoscaffolds characterized herein illustrate that they are an excellent candidate as an enzymatically initiated peptide delivery platform.

Microbial fuel cells (MFCs) are promising devices for sustainable energy production, wastewater treatment and biosensors. Anode materials directly interact with electricigens and accept electrons between cells, playing an important role in determining the performance of MFCs. In this study, a novel carbon nanotubes (CNTs) and polyaniline (PANI) nanocomposite film modified Indium-tin oxide (ITO) anode was fabricated through graft polymerization of PANI after the modification of γ-aminopropyltriethoxysilane (APTES) on ITO substrate, which was followed by layer-by-layer (LBL) self-assembling of CNTs and PANI alternatively on its surface. (CNTs/PANI)n/APTES/ITO electrode with low charge transfer resistance showed better electrochemical behavior compared to the bare ITO electrode. Twelve layers of CNTs/PANI decorated ITO electrode with an optimal nanoporous network exhibited superior biocatalytic properties with a maximal current density of 6.98 µA/cm2, which is 26-fold higher than that of conventional ITO electrode in Shewanella loihica PV-4 bioelectrochemical system. MFCs with (CNTs/PANI)12/APTES/ITO as the anode harvested a maximum output power density of 34.51 mW/m2, which is 7.5-fold higher than that of the unmodified ITO electrode. These results demonstrate that (CNTs/PANI)12/APTES/ITO electrode has superior electrochemical and electrocatalytic properties compared to the bare ITO electrode, while the cellular toxicity of CNTs has an effect on the performance of MFC with (CNTs/PANI)n/APTES/ITO electrode.