Synergistic Pharmacological Therapy to Modulate Glial Cells in Spinal Cord Injury

Current treatments for modulating the glial-mediated inflammatory response after spinal cord injury (SCI) have limited ability to improve recovery. This is quite likely due to the lack of a selective therapeutic approach acting on microgliosis and astrocytosis, the glia components most involved after trauma, while maximizing efficacy and minimizing side effects. A new nanogel that can selectively release active compounds in microglial cells and astrocytes is developed and characterized. The degree of selectivity and subcellular distribution of the nanogel is evaluated by applying an innovative super-resolution microscopy technique, expansion microscopy. Two different administration schemes are then tested in a SCI mouse model: in an early phase, the nanogel loaded with Rolipram, an anti-inflammatory drug, achieves significant improvement in the animal's motor performance due to the increased recruitment of microglia and macrophages that are able to localize the lesion. Treatment in the late phase, however, gives opposite results, with worse motor recovery because of the widespread degeneration. These findings demonstrate that the nanovector can be selective and functional in the treatment of the glial component in different phases of SCI. They also open a new therapeutic scenario for tackling glia-mediated inflammation after neurodegenerative events in the central nervous system.

β-Cyclodextrin functionalized agarose-based hydrogels for multiple controlled drug delivery of ibuprofen

Agarose hydrogels are three-dimensional hydrophilic polymeric frameworks characterised by high water content, viscoelastic properties, and excellent ability as cell and drug delivery systems. However, their hydrophilicity as gel systems makes loading of hydrophobic drugs difficult and often ineffective. The incorporation of amphiphilic molecules (e.g. cyclodextrins) into hydrogels as hosts able to form inclusion complexes with hydrophobic drugs could be a possible solution. However, if not properly confined, the host compounds can get out of the network resulting in uncontrolled release. Therefore, in this work, β-cyclodextrins-based host-guest supramolecular hydrogel systems were synthesised, with β-cyclodextrins (β-CD) covalently bound to the polymeric network, preventing leakage of the host molecules. Hydrogels were prepared at two different β-CD-functionalized polyvinyl alcohol (PVA)/agarose ratios, and characterised chemically and physically. Then ibuprofen, a drug often used as a gold standard in studies involving β-CD both in its hydrophilic and hydrophobic forms, was selected to investigate the release behavior of the synthesised hydrogels and the influence of β-CD on the release. The presence of β-CD linked to the polymeric 3D network ensured a higher and prolonged release profile for the hydrophobic drug and also seemed to have some influence on the hydrophilic one.

Molecular Recognition of Aromatics in Spherical Nanocages

In general, due to the lack of efficient specific molecular interactions, achieving host-guest molecular recognition inside large and neutral metal-organic cages (MOCs) is challenging. Preferential molecular recognition of aromatics using the internal binding sites of interlocked icosahedral (i. e., spherical) M12 L8 MOCs within poly-[n]-catenane (1) is reported. The guest absorption was monitored directly in the solid-state by consecutive single-crystal-to-single-crystal (SCSC) reactions in a gas-solid environment, in single-crystal X-ray diffraction (SC-XRD) experiments. The preferential guest uptake was corroborated by density functional theory (DFT) calculations by determining the host-guest interaction energy (Ehost-guest ) with a nitrobenzene (NB)≫p-xylene (p-xy)≫o-dichlorobenzene (o-DCB) trend (i. e., from 44 to 25 kcal mol-1 ), assessing the XRD outcomes. Combining SC-XRD, DFT and solid-state 13 C NMR, the exceptional stability of the M12 L8 cages, together with the guest exchange/release properties were rationalized by considering the presence of mechanical bonds (efficient π-π interactions) and by the pyridine's rotor-like behaviour (with 3 kcal mol-1 rotational energy barrier). The structure-function properties of M12 L8 makes 1 a potential candidate in the field of molecular sensors.

Phase transitions of aqueous solutions of Pluronic F68 in the presence of Diclofenac Sodium

In recent years, advancements in bioengineering and materials science have witnessed increasing interest in synthetic polymers capable of fulfilling various applications. Owing to their distinctive properties, Pluronics can be used as nano-drug carriers, to deliver poorly water-soluble drugs, and as model systems to study colloidal science by tuning amphiphilic properties. In this work, we investigated the effect of diclofenac sodium on the self-assembly and thermoresponsive crystallization of Pluronic F68 in water solutions, by employing experimental rheology and Nuclear Magnetic Resonance (NMR). We built a complete phase diagram as a function of temperature and concentration for 45 wt% Pluronic F68 with various amounts of diclofenac sodium in water. The morphological transitions were followed as a function of temperature via linear rheology. We extrapolated the transition temperatures - identifying distinct phases - as a function of the drug concentration and proposed an empirical model for their prediction. NMR analysis provided further information on the structural characteristics of the systems, shedding light on the interactions between F68 and diclofenac sodium. Although dealing with a pharmaceutical salt, the study is focused on a colloidal system and its interaction with a binding molecule, that is of general interest for colloidal science.

Design of Functional Pluronic-Based Precursors for Tailoring Hydrogel Thermoresponsiveness and Cell-Adhesive Properties

In this study, functional Pluronic F127 precursors were designed and synthesized for the preparation of thermosensitive hydrogels. Using linear Pluronic thioacetate and Pluronic multi-acrylate precursors, F127-based hydrogels were prepared through thioacetate deprotection-mediated Michael-type addition. The properties of these gels were compared to those obtained through free radical crosslinking of F127 diacrylate. Temperature was found to have a clear influence on gel swelling as a result of F127 thermoresponsiveness. The macromolecular architecture and functionality of the precursors were also optimized and characterized in terms of gelation kinetics and drug diffusion. In vitro tests were conducted on fibroblasts and endothelial cells to assess their response to cellular adhesion with Pluronic gels that were functionalized with an RGD peptide or pretreated with serum proteins to promote cell adhesion. This study provides a method for creating tailored hydrogels suitable for various biomedical applications, such as soft-tissue engineering, cell encapsulation, wound healing, and sustained delivery of therapeutic molecules.

Hocus Pocus: The Role Of Handheld Ultrasonography In Predicting Disease Extension And Endoscopic Activity In Ulcerative Colitis

BACKGROUND

Ulcerative colitis (UC) assessment still requires ileocolonoscopy (IC). Intestinal ultrasound (IUS) has emerged as a non-invasive assessment tool, and the Milan Ultrasound Criteria (MUC) score has been validated to estimate and grade UC disease activity. Recently, handheld IUS (HHIUS) has been used in several clinical settings, but data about its use in UC are limited. We aimed to evaluate the diagnostic accuracy of HHIUS compared to conventional (IUS) in detecting UC extension and activity.

PATIENTS AND METHODS

From November 2021 to September 2022, we prospectively enrolled UC patients afferent to our third-level IBD Unit for IC evaluation. Patients underwent IC, HHIUS, and IUS. Ultrasound activity was defined by MUC > 6.2, while endoscopic activity was defined by a Mayo endoscopic score (MES) > 1. Cohen's k test was applied to test the concordance between IUS-MUC and HHIUS-MUC after MUC dichotomization (MUC>6.2, yes/no).

RESULTS

86 patients with UC were enrolled. No significant difference was recorded between IUS and HHIUS at the per-segment extension (p=N.S.), and both procedures were comparable in terms of results of bowel wall thickness (BWT) and bowel wall stratification (BWS) assessment (p=N.S.). IUS and HHIUS displayed excellent agreement when the MUC score system was applied (k = 0.86, p<0.01).

CONCLUSION

Handheld intestinal ultrasound and IUS are comparable in UC extension definition and MUC evaluation. HHIUS could be reliable for detecting disease activity and estimating its extension, providing close monitoring. It also represents a non-invasive, easily practicable investigation, allowing immediate medical decisions with significant time and cost advantages.

Bijels as a Fluid Labyrinth for Drugs: The Effect of Nanoparticles on the Release Kinetics of Ethosuximide and Dimethyl Fumarate

Bijels (bicontinuous interfacially jammed emulsion gels) raised an increasing interest as biomaterials for controlled drug delivery due to their biphasic nature organized in mesoscopic tortuous domains. Two bijel formulations were prepared and explored as delivery systems for both hydrophilic and lipophilic drugs, ethosuximide and dimethyl fumarate. The two bijel-like structures, based on polymerized ε-caprolactone/water, differ in the stabilizing nanoparticle hydroxyapatite (inorganic) and nanogel-based nanoparticles (organic). Diffusion nuclear magnetic resonance spectroscopy has been used to characterize the bijel structure and the transport behavior of the drug molecules confined within the water/organic interconnected domains. A reduced diffusion coefficient is observed for several concentrations of the drugs and both bijel formulations. Moreover, in vitro release profiles also reveal the effect of the microstructure and drug-nanoparticle interactions.

Insights into the Effect of Lithium Doping on the Deep Eutectic Solvent Choline Chloride:Urea

Choline-based deep eutectic solvents (DESs) are potential candidates to replace flammable organic solvent electrolytes in lithium-ion batteries (LIBs). The effect of the addition of a lithium salt on the structure and dynamics of the material needs to be clarified before it enters the battery. Here, the archetypical DES choline chloride:urea at 1:2 mole fraction has been added with lithium chloride at two different concentrations and the effect of the additional cation has been evaluated with respect to the non-doped system via multinuclear NMR techniques. ¹H and ⁷Li spin-lattice relaxation times and diffusion coefficients have been measured between 298 K and 373 K and revealed a decrease in both rotational and translational mobility of the species after LiCl doping at a given temperature. Temperature dependent ³⁵Cl linewidths reflect the viscosity increase upon LiCl addition, yet keep track of the lithium complexation. Quantitative indicators such as correlation times and activation energies give indirect insights into the intermolecular interactions of the mixtures, while lithium single-jump distance and transference number shed light into the lithium transport, being then of help in the design of future DES electrolytes.

Implications of Anion Structure on Physicochemical Properties of DBU-Based Protic Ionic Liquids

Protic ionic liquids (PILs) are potential candidates as electrolyte components in energy storage devices. When replacing flammable and volatile organic solvents, PILs are expected to improve the safety and performance of electrochemical devices. Considering their technical application, a challenging task is the understanding of the key factors governing their intermolecular interactions and physicochemical properties. The present work intends to investigate the effects of the structural features on the properties of a promising PIL based on the 1,8-diazabicyclo[5.4.0]undec-7-ene (DBUH⁺) cation and the (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl)imide (IM14^–) anion, the latter being a remarkably large anion with an uneven distribution of the C–F pool between the two sides of the sulfonylimide moieties. For comparison purposes, the experimental investigations were extended to PILs composed of the same DBU-based cation and the trifluoromethanesulfonate (TFO^–) or bis(trifluoromethanesulfonyl)imide (TFSI^–) anion. The combined use of multiple NMR methods, thermal analyses, density, viscosity, and conductivity measurements provides a deep characterization of the PILs, unveiling peculiar behaviors in DBUH-IM14, which cannot be predicted solely on the basis of differences between aqueous pK_a values of the protonated base and the acid (ΔpK_a). Interestingly, the thermal and electrochemical properties of DBUH-IM14 turn out to be markedly governed by the size and asymmetric nature of the anion. This observation highlights that the structural features of the precursors are an important tool to tailor the PIL’s properties according to the specific application.

Post-operative morbidity in Crohn's disease: what is the impact of patient-, disease- and surgery-related factors?

PURPOSE

Over 50% of patients suffering from Crohn's disease (CD) require surgery in their lifetime. Predictors/risk factors of post-operative morbidity and mortality in CD are poorly investigated. We aimed to assess the risk factors of post-operative morbidity/mortality in CD.

METHODS

We performed a retrospective cohort study in which all CD patients operated and followed up at our tertiary Inflammatory Bowel Disease Centre from 2014 to 2019 were enrolled. For each patient, we evaluated patient-dependent, disease-dependent and surgery-dependent variables. All patients underwent small bowel and/or colic resections.

RESULTS

Of the 165 operated patients, forty-two (25.5%) developed post-operative complications (major complication rate = 9.8%) including wound infection (12.1%), respiratory complications (4.8%), prolonged ileum (4.2%), anastomotic leak (3.6%), urinary infections (3%), abdominal abscess (2.4%), anastomotic bleeding (3.6%), abdominal bleeding (1.2%) and obstruction (0.6%). Two subjects (1.2%) required re-operation within 30 days, and one died. A surgery duration < 141 min was predictive of a better post-operative outcome (sensitivity 80.9%, specificity 43.1%, PPV 32.7%, NPV 86.9%). The multivariable analysis showed stricturing/fistulizing behaviour (OR 3.7, 95% CI 1.6-6.4, p = 0.02), need for total parenteral nutrition (OR 4.1, 95% CI 2.4-9.2, p = 0.01), pre-operative bowel cleansing (OR 0.6, 95% CI 0.41-0.83, p = 0.01) and surgery duration < 141 min (OR 0.2, 95% CI 0.08-0.7, p = 0.03) as the only risk factors associated with post-operative morbidities.

CONCLUSIONS

About 25% of CD patients develop post-operative complications. Several patient-related, disease-related and surgery-related factors should be considered risk factors for post-operative morbidity. The recognition of these factors, as well as a multidisciplinary approach to the pre-operative management of CD, could reduce post-operative complications.

Mechanochemical synthesis of mechanical bonds in M12L8 poly-[n]-catenanes

Using mechanochemistry by grinding TPB and ZnBr₂, an amorphous poly-[n]-catenane of interlocked M12L8 nanocages is obtained in good yields (∼80%) and within 15 minutes. The mechanical bond among the icosahedral M12L8 cages in the amorphous phase has been demonstrated by single crystal XRD, powder XRD and FT-IR spectroscopy following an amorphous-to-crystalline transformation by guest uptake of the amorphous phase. High-resolution solid-state ¹³C NMR spectroscopy gives insights into the local structure of the amorphous catenane focusing on TPB aromatic-aromatic interactions.

In Silico Preliminary evaluation of Cx601 as new therapeutic approach in hospital clinical paths

 

Crohn's disease is a chronic inflammatory bowel disease characterized by transmural inflammation and fistula formation. Perianal fistulas are a common complication of Crohn's disease and are estimated to affect up to 28% of patients in the first two decades after diagnosis, particularly those with colonic disease and rectal involvement. Complex perianal fistulas in Crohn's disease are challenging to treat, severely impair patients' quality of life and cause substantial morbidity. Allogeneic, expanded, adipose-derived stem cells (Cx601) are a promising new therapeutic approach, although their high cost is often discouraging. We aimed at assessing the safety and efficacy of this treatment in patients with complex perianal fistulas in patients with Crohn's disease. Therefore, we conducted a meta-analysis in order to evaluate this new therapeutic approach before introducing it as standard of care. We examined 8 studies published in the last 10 years, 5 of which were selected for the final analysis. The primary outcome assessed was the combined fistula remission (clinical + imaging) assessed through the clinical examination and MRI, the control being the traditional medical strategies (ie, antibiotics, immunomodulators and anti-tumour necrosis factor agents). We registered a total of 128 events (lack of remission) in the control group vs 94 in the experimental one (Confidence Interval for OR of 0,12-0,31, P &lt; 0,001). Our “in silico” assessment is reliable, being the introduction of (Cx601) an innovative and effective treatment. Further insights will be provided by the INSPIRE registry, a multinational post-marketing study whose main objective is the evaluation of the real-world clinical effectiveness and safety of (Cx601) in patients affected by Crohn's disease with complex perianal fistulas for a duration of 36 months, to which our University “Federico II” is actively taking part.

Key messages

Disability reduction is an important goal in cronh therapeutic path of care. Our “in silico” assessment may support the introduction of (Cx601) an innovative and effective treatment.

Crohn's disease and Takayasu's arteritis: are they associated?

OBJECTIVE

Different types of vasculitis can occur in patients with inflammatory bowel disease [IBD], but large vessels vasculitis seems to be the most prevalent. Indeed, the presence of both Crohn's disease [CD] and Takayasu's arteritis [TAK] has previously been reported, with higher prevalence in young women between the second and the third decade of life. This article aims to provide clinicians with an accurate picture of the most common clinical features and current treatment strategy for patients with both CD and TAK.

PATIENTS AND METHODS

We described the coexistence of CD and TAK in three young women and also performed an extensive literature review about the association of these two immune-related disorders. Research on PubMed server was performed typing the terms "Takayasu's arteritis and inflammatory bowel disease", "Takayasu's arteritis and Crohn's disease", and "Takayasu's arteritis and Ulcerative colitis".

RESULTS

Although the association of CD with TAK is uncommon, due to the severity of both diseases, concomitance in the same patient may significantly complicate the diagnostic and therapeutic work-up. In addition, since TAK can compromise intestinal vasculature, it may possibly exacerbate the clinical course of patients with IBD. All patients we reported underwent surgery due to IBD complications and two of them started biological therapy with different outcomes.

CONCLUSIONS

Early detention of these conditions has a great importance for both gastroenterologists and immunologists, for ensuring a tailored multidisciplinary management, possibly in order to identify a common therapy for these two immune-related disorders.

The Intermolecular NOE Depends on Isotope Selection: Short Range vs Long Range Behavior

The nuclear Overhauser effect (NOE) is a powerful tool in molecular structure elucidation, combining the subtle chemical shift of NMR and three-dimensional information independent of chemical connectivity. Its usage for intermolecular studies, however, is fundamentally limited by an unspecific long-ranged interaction behavior. This joint experimental and computational work shows that proper selection of interacting isotopes can overcome these limitations: Isotopes with strongly differing gyromagnetic ratios give rise to short-ranged intermolecular NOEs. In this light, existing NOE experiments need to be re-evaluated and future ones can be designed accordingly. Thus, a new chapter on intermolecular structure elucidation is opened.

Xenon Diffusion in Ionic Liquids with Blurred Nanodomain Separation

The dynamics of xenon gas, loaded in a series of 1-alkyl-3-methylimidazolium based ionic liquids, probes the formation of increasingly blurred polar/apolar nanodomains as a function of the anion type and the cation chain length. Exploiting ¹²⁹ Xe NMR spectroscopy techniques, like Pulse Gradient Spin Echo (PGSE) and inversion recovery (IR), the diffusion motion and relaxation times are determined for 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C_n C₁ im][TFSI]. A correlation between the ILs nano-structure and both xenon diffusivity and relaxation times, as well as chemical shifts, is outlined. Interestingly, comparison with previous results of the same properties in the homologous imidazolium chlorides and hexafluorophospate shows an opposite trend with the alkyl chain length. Classical molecular dynamics (MD) simulations are used to calculate the xenon and cation and anion diffusion coefficients in the same systems, including imidazolium cations with longer chains (n=4, 6, 8 … 20). An almost quantitative agreement with the experiments validates the MD simulations and, at the same time, provides the necessary structural and dynamic microscopic insights on the nano-segregation and diffusion of xenon in bistriflimide, chloride and hexafluorphosphate salts allowing to observe and rationalize the shaping effect of the cation in the nanostructure.

Azathioprine for prevention of clinical recurrence in Crohn's disease patients with severe endoscopic recurrence: an IG-IBD randomized double-blind trial

OBJECTIVE

The recurrence of Crohn's Disease after ileo-colonic resection is a crucial issue. Severe endoscopic lesions increase the risk of developing early symptoms. Prevention and treatment of post-operative Endoscopic Recurrence (ER) have been studied with conflicting results. We compare effi cacy of azathioprine (AZA) vs. high-dose 5-aminosalicylic acid (5-ASA) in preventing clinical recurrence and treating severe post-operative ER.

PATIENTS AND METHODS

We performed a 1-year multicenter randomized double-blind double-dummy trial. Primary end-points were endoscopic improvement and therapeutic failure (clinical recurrence or drug discontinuation due to lack of efficacy or adverse events) 12 months after randomization. We also performed a post-trial analysis on symptomatic and endoscopic outcomes 10 years after the beginning of the trial, with a median follow-up of 60 months.

RESULTS

Therapeutic failure occurred in 8 patients (17.4%) within 12 months from randomization, with no significant difference between patients treated with 5-ASA (20.8%, 5 patients) and those with AZA (13.6%, 3 patients). Therapeutic failure was due to clinical recurrence in the 5-ASA group and to adverse events in the AZA group. Endoscopic improvement at 12 months was observed in 8 patients, 2 (11.8%) in the 5-ASA group and 6 (30%) in the AZA group. No serious adverse event was recorded. At the post-trial analysis (median follow-up 60 months), 47.8% (22/46) of patients experienced clinical recurrence: 54.2% (13/24) in the 5-ASA group and 40.9% (9/22) in the AZA group, p=0.546. Patients treated with AZA had lower risk of drug escalation. Clinical recurrence was associated with smoking (p=0.031) and previous surgery (p=0.003).

CONCLUSIONS

Our trial indicates that there was no difference in terms of treatment failure between 5-ASA and AZA in patients with severe ER. The main limit of AZA is its less favorable safety profile.

Surgical management of acquired rectourethral fistula: a retrospective analysis of 52 consecutive patients

BACKGROUND

Acquired rectourethral fistula (RUF) is an uncommon complication mostly resulting from surgery or radiation. Standardization of the surgical management is lacking. The aim of this study was to report our experience with surgery for RUF.

METHODS

This was a retrospective study of a prospectively maintained clinical database. The surgical strategy was tailored to complexity of RUF, presence of sepsis, history of radiation and residual urinary/fecal functionality. Outcomes measured were RUF closure and permanent fecal/urinary diversion. Impact of radiotherapy was also assessed.

RESULTS

Between November 2002 and January 2019, 52 patients were identified (100% males). Median follow-up was 10.5 (0.5-16.8) years. Three patients had RUF closure after conservative management. The remaining 49 patients had a total of 76 procedures. The cumulative closure rate after the first, second and third attempt was 55.1%, 85.7% and 95.9%, respectively. Fistula closure together with preservation of the fecal and urinary function was achieved in 49%, 65.3% and 67.3% after the first, second and third repair, respectively. The overall success rate for transanal, transperineal, restorative transabdominal and non-restorative transabdominal procedures was 35.7%, 64.3%, 57.1% and 94.1%, respectively. A significantly higher rate of urinary/intestinal stomas was observed in the irradiated vs non-irradiated patients (84.2% vs 42.4%; p = 0.004).

CONCLUSIONS

Surgery ensured healing in 96% of the patients. Radiotherapy led to higher rate of permanent urinary/fecal diversion. Nearly all irradiated patients who had transabdominal repair end up with a definitive stoma. When transperineal repair with gracilis flap interposition was used, the rate of fistula closure approached 90%. A treatment algorithm is proposed.

Xenon Dynamics in Ionic Liquids: A Combined NMR and MD Simulation Study

The translational dynamics of xenon gas dissolved in room-temperature ionic liquids (RTILs) is revealed by ¹²⁹Xe NMR and molecular dynamics (MD) simulations. The dynamic behavior of xenon gas loaded in 1-alkyl-3-methylimidazolium chloride, [C_nC₁im]Cl (n = 6, 8, 10), and hexafluorophosphate, [C_nC₁im][PF₆] (n = 4, 6, 8, 10) has been determined by measuring the ¹²⁹Xe diffusion coefficients and NMR relaxation times. The analysis of the experimental NMR data demonstrates that, in these representative classes of ionic liquids, xenon motion is influenced by the length of the cation alkyl chain and anion type. ¹²⁹Xe spin–lattice relaxation times are well described with a monoexponential function, indicating that xenon gas in ILs effectively experiences a single average environment. These experimental results can be rationalized based on the analysis of classical MD trajectories. The mechanism described here can be particularly useful in understanding the separation and adsorption properties of RTILs.

Magnetic Resonance Imaging and Molecular Dynamics Characterization of Ionic Liquid in Poly(ethylene oxide)-Based Polymer Electrolytes

Ternary systems consisting of polymers, lithium salts, and ionic liquids (ILs) are promising materials for the development of next-generation lithium batteries. The ternary systems combine the advantages of polymer-salt and IL-salt systems, thus providing media with high ionic conductivity and solid-like mechanical properties. In this work, we apply nuclear magnetic resonance 1H microimaging [magnetic resonance imaging (MRI)] techniques and molecular dynamics (MD) simulations to study the translational and rotational dynamics of the N-butyl-N-methylpyrrolidinium (PYR14) cation in poly(ethylene oxide) (PEO) matrices containing the lithium bis(trifluoromethanesulfonyl) imide salt (LiTFSI) and the PYR14TFSI IL. The analysis of diffusion-weighted images in PEO/LiTFSI/PYR14TFSI samples with varying mole ratios (10:1:x, with x = 1, 2, 3, and 4) shows, in a wide range of temperatures, a spatially heterogeneous distribution of PYR14 diffusion coefficients. Their weight-averaged values increase with IL content but remain well below the values estimated for the neat IL. The analysis of T2 (spin-spin relaxation) parametric images shows that the PEO matrix significantly hinders PYR14 rotational freedom, which is only partially restored by increasing the IL content. The MD simulations, performed on IL-filled cavities within the PEO matrix, reveal that PYR14 diffusion is mainly affected by Li/TFSI coordination within the IL phase. In agreement with MRI experiments, increasing the IL content increases the PYR14 diffusion coefficients. Finally, the analysis of MD trajectories suggests that Li diffusion mostly develops within the IL phase, although a fraction of Li cations is strongly coordinated by PEO oxygen atoms.

Anions as Dynamic Probes for Ionic Liquid Mixtures

Ionic liquid (IL) mixtures have been proposed as a viable alternative to rationally fine-tune the physicochemical properties of ILs for a variety of applications. The understanding of the effects of mixing ILs on the properties of the mixtures is however only in the very early stages. Two series of ionic liquid mixtures, based on the 1-ethyl-3-methylimidazolium and 1-dodecyl-3-methylimidazolium cations, and having a common anion (tetrafluoroborate or bis(trifluoromethylsulfonyl)imide), have been prepared and deeply characterized via multiple NMR techniques. Diffusion and relaxation methods combined with 2D ion-ion correlation (nuclear Overhauser enhancement) experiments have been used for a better understanding of the interplay between dynamics and structure of IL mixtures. A crucial role of the anion in driving the mixture's behavior emerged, making them important "dynamic probes" for gaining information of the polar and nonpolar regions of ionic liquids and their mixtures.

Spectral deconvolution in electrophoretic NMR to investigate the migration of neutral molecules in electrolytes

Electrophoretic nuclear magnetic resonance (eNMR) is a powerful tool in studies of nonaqueous electrolytes, such as ionic liquids. It delivers electrophoretic mobilities of the ionic constituents and thus sheds light on ion correlations. In applications of liquid electrolytes, uncharged additives are often employed, detectable via ¹ H NMR. Characterizing their mobility and coordination to charged entities is desirable; however, it is often hampered by small intensities and ¹ H signals overlapping with major constituents of the electrolyte. In this work, we evaluate methods of phase analysis of overlapping resonances to yield electrophoretic mobilities even for minor constituents. We use phase-sensitive spectral deconvolution via a set of Lorentz distributions for the investigation of the migration behavior of additives in two different ionic liquid-based lithium salt electrolytes. For vinylene carbonate as an additive, no field-induced drift is observed; thus, its coordination to the Li⁺ ion does not induce a correlated drift with Li⁺ . On the other hand, in a solvate ionic liquid with tetraglyme (G4) as an additive, a correlated migration of tetraglyme with lithium as a complex solvate cation is directly proven by eNMR. The phase evaluation procedure of superimposed resonances thus broadens the applicability of eNMR to application-relevant complex electrolyte mixtures containing neutral additives with superimposed resonances.

TEMPO-Nanocellulose/Ca2+ Hydrogels: Ibuprofen Drug Diffusion and In Vitro Cytocompatibility

Stable hydrogels with tunable rheological properties were prepared by adding Ca2+ ions to aqueous dispersions of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized and ultra-sonicated cellulose nanofibers (TOUS-CNFs). The gelation occurred by interaction among polyvalent cations and the carboxylic units introduced on TOUS-CNFs during the oxidation process. Both dynamic viscosity values and pseudoplastic rheological behaviour increased by increasing the Ca2+ concentration, confirming the cross-linking action of the bivalent cation. The hydrogels were proved to be suitable controlled release systems by measuring the diffusion coefficient of a drug model (ibuprofen, IB) by high-resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy. IB was used both as free molecule and as a 1:1 pre-formed complex with β-cyclodextrin (IB/β-CD), showing in this latter case a lower diffusion coefficient. Finally, the cytocompatibility of the TOUS-CNFs/Ca2+ hydrogels was demonstrated in vitro by indirect and direct tests conducted on a L929 murine fibroblast cell line, achieving a percentage number of viable cells after 7 days higher than 70%.

Evidence of superdiffusive nanoscale motion in anionic polymeric hydrogels: Analysis of PGSE- NMR data and comparison with drug release properties

Polymeric hydrogels are promising candidates for drug delivery applications, thanks to their ability to encapsulate, transport and release a wide range of chemicals. The successful application of these materials requires a deep understanding of the mechanisms governing solute transport at the nanoscale and its impact on release kinetics. In this work, we investigate the translational diffusion of ibuprofen loaded in anionic agarose-carbomer (AC) hydrogels by ¹H high resolution magic angle spinning (HR-MAS) NMR spectroscopy, and compare it to its macroscopic release kinetics. The analysis of the experimental NMR data provides the first evidence of superdiffusion for ibuprofen in AC hydrogels. Superdiffusive transport is observed in the majority of our samples, especially those with the smallest mesh size (7 nm) and highest ibuprofen concentrations (90-120 mg/mL). This outcome is rationalized in terms of heavy-tailed distributions of spatial displacements (Lèvy flights) and of waiting times, which depend on the nanoscopic structural heterogeneity of the gels and the strong but reversible association between ibuprofen and the agarose matrix.

On the structural origin of free volume in 1-alkyl-3-methylimidazolium ionic liquid mixtures: a SAXS and 129Xe NMR study

Ionic liquid (IL) mixtures enable the design of fluids with finely tuned structural and physicochemical properties for myriad applications. In order to rationally develop and design IL mixtures with the desired properties, a thorough understanding of the structural origins of their physicochemical properties and the thermodynamics of mixing needs to be developed. To elucidate the structural origins of the excess molar volume within IL mixtures containing ions with different alkyl chain lengths, 3 IL mixtures containing 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ILs have been explored in a joint small angle X-ray scattering (SAXS) and 129Xe NMR study. The apolar domains of the IL mixtures were shown to possess similar dimensions to the largest alkyl chain of the mixture with the size evolution determined by whether the shorter alkyl chain was able to interact with the apolar domain. 129Xe NMR results illustrated that the origin of excess molar volume in these mixtures was due to fluctuations within these apolar domains arising from alkyl chain mismatch, with the formation of a greater number of smaller voids within the IL structure. These results indicate that free volume effects for these types of mixtures can be predicted from simple considerations of IL structure and that the structural basis for the formation of excess molar volume in these mixtures is substantially different to IL mixtures formed of different types of ions.

Red flags for appropriate referral to the gastroenterologist and the rheumatologist of patients with inflammatory bowel disease and spondyloarthritis

Collaboration between gastroenterologists and rheumatologists is recommended for the correct management of patients with associated spondyloarthritis (SpA) and inflammatory bowel disease (IBD). We aimed to establish the appropriateness of several red flags for a prompt specialist referral. A systematic review of the literature was performed using the GRADE method to describe the prevalence of co-existing IBD-SpA and the diagnostic accuracy of red flags proposed by a steering committee. Then, a consensus among expert gastroenterologists and rheumatologists (10 in the steering committee and 13 in the expert panel) was obtained using the RAND method to confirm the appropriateness of each red flag as 'major' (one sufficient for patient referral) or 'minor' (at least three needed for patient referral) criteria for specialist referral. The review of the literature confirmed the high prevalence of co-existing IBD-SpA. Positive and negative predictive values of red flags were not calculated, given the lack of available data. A consensus among gastroenterology and rheumatology specialists was used to confirm the appropriateness of each red flag. Major criteria to refer patients with SpA to the gastroenterologist included: rectal bleeding, chronic abdominal pain, perianal fistula or abscess, chronic diarrhoea and nocturnal symptoms. Major criteria to refer patients with IBD to the rheumatologist included: chronic low back pain, dactylitis, enthesitis and pain/swelling of peripheral joints. Several major and minor red flags have been identified for the diagnosis of co-existing IBD-SpA. The use of red flags in routine clinical practice may avoid diagnostic delay and reduce clinic overload.

On the parallelism between the mechanisms behind chromatography and drug delivery: the role of interactions with a stationary phase

A huge number of studies and work in the drug delivery literature are focused on understanding and modeling transport phenomena, the pivotal point for a good device design. The rationalization of all phenomena involved is fundamental, but several concerns arise leaving many issues unsolved. In order to change the point of view we decided to focus our attention on the parallelisms between two fields that seem to be very far from each other: chromatography and drug release. Taking advantages of the studies conducted by many researchers using chromatographic columns we decided to explain all the phenomena involved in drug delivery considering sodium ibuprofen (IP) molecules as analytes and hydrogel as a stationary phase. In particular, we considered not only diffusion, but also drug-polymer interactions as adsorption on the stationary phase and drug-drug interactions as aggregation of analytes. The hydrogel investigated is a promising formulation made of agarose and carbomer 974p (AC) loaded with IP, a non-steroidal common anti-inflammatory drug. The self-diffusion coefficient of IP in AC formulations was measured by using an innovative method based on a magic angle spinning NMR spectroscopic technique to produce high resolution (liquid-like) spectra. This method (HR-MAS NMR) is used in combination with pulsed field gradient spin echo (PGSE) liquid-state techniques. The model predictions satisfactorily match with the experimental data obtained in water and the gel environment, indicating that the model presented here, despite its simplicity, is able to describe the key phenomena governing the device behavior and could be used to rationalize the experimental activity.