Determination of the optimal pH for doxorubicin encapsulation in polymeric micelles.

Hypothesis: The anticancer drug doxorubicin hydrochloride (DX) shows a high solubility in aqueous media thanks to the positive charge in the ammonium group. This feature, however, affects the drug encapsulation in the hydrophobic domains of polymeric micelles (PMs) used for the targeted delivery of the drug. At basic pH, DX deprotonates but also acquires a negative charge in the phenolic groups of the anthracycline structure.

Nanostructured Poly-l-lactide and Polyglycerol Adipate Carriers for the Encapsulation of Usnic Acid: A Promising Approach for Hepatoprotection.

The present study investigates the utilization of nanoparticles based on poly-l-lactide (PLLA) and polyglycerol adipate (PGA), alone and blended, for the encapsulation of usnic acid (UA), a potent natural compound with various therapeutic properties including antimicrobial and anticancer activities. The development of these carriers offers an innovative approach to overcome the challenges associated with usnic acid's limited aqueous solubility, bioavailability, and hepatotoxicity. The nanosystems were characterized according to their physicochemical properties (among others, size, zeta potential, thermal properties), apparent aqueous solubility, and in vitro cytotoxicity.

Synthesis and Characterization of a Thermoresponsive Copolymer with an LCST-UCST-like Behavior and Exhibiting Crystallization.

In this work, the diblock copolymer methoxy-poly(ethylene glycol)--poly(ε-caprolactone) (MPEG--PCL) was synthesized with a block composition that allows this polymer in aqueous media to possess both an upper critical solution temperature (UCST) and a lower critical solution temperature (LCST) over a limited temperature interval. The value of the UCST, associated with crystallization of the PCL-block, depended on heating (H) or cooling (C) of the sample and was found to be CP = 32 °C and CP = 23 °C, respectively. The LCST was not affected by the heating or cooling scans; assumed a value of 52 °C (CP = CP).

Novel liposomal formulations for protection and delivery of levodopa: Structure-properties correlation.

Liposomes are promising drug carriers for a wide range of central nervous system disorders, such as Parkinson's disease (PD), since they can protect active substances from degradation and could be administered intranasally, ensuring a direct access to the brain. Levodopa (LD), the drug commonly used to treat PD, spontaneously oxidizes in aqueous solutions and thus needs to be stabilized. Our investigation focuses on the preparation and the physico-chemical characterization of mixed liposomes to vehiculate LD and two natural substances (L-ascorbic acid and quercetin) that can prevent its oxidation and contribute to the treatment of Parkinson's disease.

Conformational Disorder Analysis of the Conditionally Disordered Protein CP12 from in Its Different Redox States.

CP12 is a redox-dependent conditionally disordered protein universally distributed in oxygenic photosynthetic organisms. It is primarily known as a light-dependent redox switch regulating the reductive step of the metabolic phase of photosynthesis. In the present study, a small angle X-ray scattering (SAXS) analysis of recombinant Arabidopsis CP12 (AtCP12) in a reduced and oxidized form confirmed the highly disordered nature of this regulatory protein.

Polymeric Wet-Strength Agents in the Paper Industry: An Overview of Mechanisms and Current Challenges.

Polymeric wet-strength agents are important additives used in the paper industry to improve the mechanical properties of paper products, especially when they come into contact with water. These agents play a crucial role in enhancing the durability, strength, and dimensional stability of paper products. The aim of this review is to provide an overview of the different types of wet-strength agents available and their mechanisms of action.

Poly (diglycerol adipate) variants as enhanced nanocarrier replacements in drug delivery applications.

Sustainably derived poly(glycerol adipate) (PGA) has been deemed to deliver all the desirable features expected in a polymeric scaffold for drug-delivery, including biodegradability, biocompatibility, self-assembly into nanoparticles (NPs) and a functionalisable pendant group. Despite showing these advantages over commercial alkyl polyesters, PGA suffers from a series of key drawbacks caused by poor amphiphilic balance. This leads to weak drug-polymer interactions and subsequent low drug-loading in NPs, as well as low NPs stability.

Interactions in Aqueous Mixtures of Cationic Hydroxyethyl Cellulose and Different Anionic Bile Salts.

It is known that the reduction of blood cholesterol can be accomplished through foods containing a large number of dietary fibers; this process is partially related to the binding of bile salt to fibers. To gain new insights into the interactions between dietary fibers and bile salts, this study investigates the interactions between cationic hydroxyethyl cellulose (catHEC) and sodium deoxycholate (NaDC) or sodium cholate (NaC), which have a similar structure. Turbidity measurements reveal strong interactions between catHEC and NaDC, and under some conditions, macroscopic phase separation occurs.

Disposable Voltammetric Immunosensor for D-Dimer Detection as Early Biomarker of Thromboembolic Disease and of COVID-19 Prognosis.

In this work, we report on the development of a simple electrochemical immunosensor for the detection of D-dimer protein in human plasma samples. The immunosensor is built by a simple drop-casting procedure of chitosan nanoparticles (CSNPs) as biocompatible support, Protein A (PrA), to facilitate the proper orientation of the antibody sites to epitopes as a capture biomolecule, and the D-dimer antibody onto a carboxyl functionalized multi-walled carbon nanotubes screen printed electrode (MWCNTs-SPE). The CSNPs have been morphologically characterized by Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS) techniques.

Noncovalent Bile Acid Oligomers as Facial Amphiphilic Antimicrobials.

New antimicrobial agents are needed to address the ever-growing risk of bacterial resistance, particularly for methicillin- and vancomycin-resistant (). Here, we report a class of bile acid oligomers as facial amphiphilic antimicrobials, which are noncovalently fabricated by cholic acid (CA) and deoxycholic acid (DCA) with polyamines (e.g.

Lignin Nanoparticles as Sustainable Photoprotective Carriers for Sunscreen Filters.

Sunscreen filters may be degraded after prolonged UV exposure with loss of their shielding property and generation of harmful radical species. They are contained in cosmetic formulations in high concentrations, so the improvement of photostability is of relevance for safety concerns. We report here that lignin nanoparticles are sustainable carriers and photostabilizers of two common UV chemical filters, namely, avobenzone and octyl methoxycinnamate.

Complexation and organization of doxorubicin on polystyrene sulfonate chains: impacts on doxorubicin dimerization and quenching.

Anthracycline doxorubicin hydrochloride (DX) is a positively charged fluorescent drug, which in water self-associates into non-fluorescent antiparallel dimers upon increasing concentration and/or ionic strength. The positive charge of DX allows for complexation with negatively charged polymers and drug carriers. The fluorescence of DX following complexation with polyanion polystyrene sulfonate (PSS) is studied here.

Transport of cationic liposomes in a human blood brain barrier model: Role of the stereochemistry of the gemini amphiphile on liposome biological features.

Hypothesis: The positive charge on liposome surface is known to promote the crossing of the Blood brain barrier (BBB). However, when diastereomeric cationic gemini amphiphiles are among lipid membrane components, also the stereochemistry may affect the permeability of the vesicle across the BBB.

Experiments: Liposomes featuring cationic diasteromeric gemini amphiphiles were formulated, characterized, and their interaction with cell culture models of BBB investigated.

Quatsomes Formulated with l-Prolinol-Derived Surfactants as Antibacterial Nanocarriers of (+)-Usnic Acid with Antioxidant Activity.

The efficacy of the treatment of bacterial infection is seriously reduced because of antibiotic resistance; thus, therapeutic solutions against drug-resistant microbes are necessary. Nanoparticle-based solutions are particularly promising for meeting this challenge because they can offer intrinsic antimicrobial activity and sustained drug release at the target site. Herein, we present a newly developed nanovesicle system of the quatsome family, composed of l-prolinol-derived surfactants and cholesterol, which has noticeable antibacterial activity even on Gram-negative strains, demonstrating great potential for the treatment of bacterial infections.

Bioderived, chiral and stable 1-dimensional light-responsive nanostructures: Interconversion between tubules and twisted ribbons.

Hypothesis: Self-assembling molecular structures responding to light stimulus are appealing for applications as sensing and drug delivery. Supramolecular nanotubes have a relevant potential in nanotechnology as they can be used to encapsulate different loads like drugs, biological macromolecules, and nanomaterials. In addition, they are suitable elements for novel supracolloidal materials.

Structurally Related Liposomes Containing -Oxide Surfactants: Physicochemical Properties and Evaluation of Antimicrobial Activity in Combination with Therapeutically Available Antibiotics.

Although liposomes are largely investigated as drug delivery systems, they can also exert a pharmacological activity if devoid of an active principle as a function of their composition. Specifically, charged liposomes can electrostatically interact with bacterial cells and, in some cases, induce bacterial cell death. Moreover, they also show a high affinity toward bacterial biofilms.

Fabrication of a New, Low-Cost, and Environment-Friendly Laccase-Based Biosensor by Electrospray Immobilization with Unprecedented Reuse and Storage Performances.

The fabrication of enzyme-based biosensors has received much attention for their selectivity and sensitivity. In particular, laccase-based biosensors have attracted a lot of interest for their capacity to detect highly toxic molecules in the environment, becoming essential tools in the fields of white biotechnology and green chemistry. The manufacturing of a new, metal-free, laccase-based biosensor with unprecedented reuse and storage capabilities has been achieved in this work through the application of the electrospray deposition (ESD) methodology as the enzyme immobilization technique.

Condensed Supramolecular Helices: The Twisted Sisters of DNA.

Condensation of DNA helices into hexagonally packed bundles and toroids represents an intriguing example of functional organization of biological macromolecules at the nanoscale. The condensation models are based on the unique polyelectrolyte features of DNA, however here we could reproduce a DNA-like condensation with supramolecular helices of small chiral molecules, thereby demonstrating that it is a more general phenomenon. We show that the bile salt sodium deoxycholate can form supramolecular helices upon interaction with oppositely charged polyelectrolytes of homopolymer or block copolymers.

Biosynthesis and physico-chemical characterization of high performing peptide hydrogels@graphene oxide composites.

Hydrogels based on short peptide molecules are interesting biomaterials with wide present and prospective use in biotechnologies. A well-known possible drawback of these materials can be their limited mechanical performance. In order to overcome this problem, we prepared Fmoc-Pheself-assembling peptides by a biocatalytic approach, and we reinforced the hydrogel with graphene oxide nanosheets.

Synthesis of 2D Porous Crystalline Materials in Simulated Microgravity.

To date, crystallization studies conducted in space laboratories, which are prohibitively costly and unsuitable to most research laboratories, have shown the valuable effects of microgravity during crystal growth and morphogenesis. Herein, an easy and highly efficient method is shown to achieve space-like experimentation conditions on Earth employing custom-made microfluidic devices to fabricate 2D porous crystalline molecular frameworks. It is confirmed that experimentation under these simulated microgravity conditions has unprecedented effects on the orientation, compactness and crack-free generation of 2D porous crystalline molecular frameworks as well as in their integration and crystal morphogenesis.

Physiology and Physical Chemistry of Bile Acids.

Bile acids (BAs) are facial amphiphiles synthesized in the body of all vertebrates. They undergo the enterohepatic circulation: they are produced in the liver, stored in the gallbladder, released in the intestine, taken into the bloodstream and lastly re-absorbed in the liver. During this pathway, BAs are modified in their molecular structure by the action of enzymes and bacteria.

Tuning lipid structure by bile salts: Hexosomes for topical administration of catechin.

The delivery of bio-active molecules through the skin is challenging given the complex structure of its outer layer, the stratum corneum. Here we explore the possibility to encapsulate natural compounds into nanocarriers containing permeation enhancers that can affect the fluidity of the stratum corneum lipids. This approach is expected to facilitate dermal or transdermal release.

Plasmon-Enhanced Optical Chirality through Hotspot Formation in Surfactant-Directed Self-Assembly of Gold Nanorods.

Plasmonically enhanced optical dichroism has attracted substantial interest for its application in optical sensing, where the interplay between chirality emanating from both molecules and plasmon-supporting structures has been regarded as a critical ingredient. Here, we experimentally demonstrate that suitably self-assembled achiral plasmonic nanostructures produce a high degree of enhancement in the optical dichroism observed from chiral molecules placed in their vicinity. Specifically, we identify a near-field enhancement associated with plasmonic hotpots as the mechanism enabling our observation of visible-NIR circular dichroism emanating from small amounts of chiral molecules.