Higher Release Research Articles

Preparation and evaluation of liposomal gel containing Neolamarckia cadamba leaves extract for anti-inflammatory activity

The objective of present research work is to develop liposomes as a carrier system for methanolic extract, its incorporation in to gel formulations and to characterize the prepared and develop liposomal gel formulation. Formulation was carried out by thin film technique. Scanning electron micrograph of the prepared nanosponges at 50.00 kx magnification showed that the liposome was porous with a smooth surface morphology and spherical shape. The porous nature of liposome was clearly observed in the SEM images. Particle size and zeta potential was determined by Malvern Zeta sizer. The particle size analysis confirmed that the prepared sample were in the nanometer range. Average particle size obtained for the formulations F1 to F5 were 162.7 nm to 195.6 nm. Zeta potential values of liposome indicated that the formulated liposomes are stable. The amount of drug being entrapped in liposome was calculated and all the prepared liposome was found to possess very high entrapment efficiency. The viscosity of liposome loaded gel is found to 6842±0.32cps. The pH of liposome loaded gel is 6.3 and spreadability is 12.11, indicating that liposome loaded gel has high release and permeability. The in vitro anti-inflammatory effect of Neolamarckia cadamba extract was evaluated against denaturation of egg albumin. The present findings exhibited a concentration dependent inhibition of protein (albumin) denaturation by Neolamarckia cadamba throughout the concentration range of 20-100μg/ml. Diclofenac sodium (at the concentration range of 20-100 μg/ml) was used as reference drug which also exhibited concentration dependent inhibition of protein denaturation; however, the effect of diclofenac sodium was found to be less active when compared with extract name. Moreover, the results demonstrated that the liposome-based drug delivery approach could be a valuable tool to improve the therapeutic efficacy of phytochemicals by improving their absorption, and bioavailability via altering their physicochemical and release properties. Keywords: Liposomes, Neolamarckia cadamba, Qualitative phytochemical screening, Thin film technique, In vitro anti-inflammatory activity.

Precursors consumption preferences and thiol release capacity of the wine yeasts Saccharomyces cerevisiae, Torulaspora delbrueckii, and Lachancea thermotolerans

The aromatic profile of wine determines its overall final quality, and among the volatile molecules that define it, varietal thiols are responsible for shaping the distinctive character of certain wine varieties. In grape must, these thiols are conjugated to amino acids or small peptides in a non-volatile form. During wine fermentation, yeasts play a principal role in expressing these aromatic compounds as they internalise and cleavage these precursors, releasing the corresponding free and aroma-impacting fraction. Here, we investigate the impact of three wine yeasts (Saccharomyces cerevisiae, Torulaspora delbrueckii and Lachancea thermotolerans) on thiol releasing in synthetic grape must fermentations supplemented with different cysteinylated (Cys-4MSP and Cys-3SH) and glutathionylated (GSH-4MSP and GSH-3SH) precursors. We demonstrate higher consumption levels of cysteinylated precursors, and consequently, higher amounts of thiols are released from them compared to glutathionylated ones. We also report a significant impact of yeast inoculated on the final thiols released. Meanwhile T. delkbrueckii exhibits a great 3SHA releasing capacity, L. thermotolerans stands out because of its high 3SH release. We also highlight the synergic effect of the co-inoculation strategy, especially relevant in the case of S. cerevisiae and L. thermotolerans mixed fermentation, that has an outstanding release of 4MSP thiol. Although our results stem from a specific experimental approach that differs from real winemaking situations, these findings reveal the potential of unravelling the specific role of different yeast species, thiol precursors and their interaction, to improve wine production processes in the context of wine aroma enhancement.

An injectable oleogel-based bupivacaine formulation for prolonged non-opioid post-operative analgesia.

Opioid-based medications remain the mainstay of post-operative pain management, even though they are associated with a plethora of adverse effects including addiction, nausea, constipation, cognitive impairment, respiratory depression, and accidental death due to overdose. Local anesthetics are effective at controlling the intense pain after surgery but their short duration of effect limits their clinical utility in post-operative pain management. In this manuscript, an optimized injectable oleogel-based formulation of bupivacaine for multi-day post-operative pain management was characterized on the benchtop and assessed in two clinically-relevant porcine post-operative pain models. Benchtop characterization verified the optimized oleogel-based bupivacaine formulation design, demonstrating a homogenous stable oleogel with sufficient injectability due to shear-thinning properties, high drug loading capacity and first-order drug release kinetics over 5days. In vivo assessment in two pig post-operative pain models demonstrated that the oleogel-based bupivacaine formulation can provide statistically significant multi-day analgesia in two routes of administration: local instillation directly into a surgical site and ultrasound-guided peripheral nerve block injection. Pharmacokinetic assessment of ALX005 found that Cmax values were not statistically different from the bupivacaine HCl control, with no clinical signs of local anesthetic systemic toxicity observed, when administering up to 2.7 and 8.1 times the control dose of bupivacaine HCl. This study demonstrates the pre-clinical safety and efficacy of an injectable oleogel-based bupivacaine formulation and explores its utility as a single-administration long-acting local anesthetic product for post-operative pain management that can be used in both local and regional anesthetic applications.

Signature of nano alumina condensation during metal combustion

The work is focused on thermal radiation originating from aluminum oxide nanoparticles formed during the combustion of an aluminum and copper oxide (Al/CuO) thermite. The light emission signature allows for the identification of condensation features important for the global energy balance of burning metal-containing systems. From a fundamental science perspective, identifying light emission signatures associated with phase changes, and in particular, with condensation that is accompanied by high energy release, will lead to new knowledge with widespread applications. The recently developed calibration-free pyrometry approach is used to isolate the radiation of interest during combustion. Processing the obtained spectra made it possible to detect the solidification of the resulting nano alumina. Knowledge of the phase transition temperature enabled the determination of the temporal behavior of the absolute temperature of aluminum oxide nanoparticles during their formation by condensation from gaseous metal suboxides. This ability to measure absolute temperature, as opposed to its reciprocal value available with the original calibration-free pyrometry approach, further enhances the diagnostic method's capabilities. The general implications of revealed peculiarities of nano alumina formation for detailed modeling of the combustion of metal-containing systems are discussed.

Nanogel: A versatile drug delivery system for the treatment of various diseases and their future perspective.

Nanogel (NG) drug delivery systems have emerged as promising tools for targeted and controlled drug release, revolutionizing treatment approaches across various diseases.Their unique physicochemical properties, such as nano size, high surface area,biocompatibility, stability, and tunable drug release, make themideal carriers for a wide range of therapeutic agents. Nanogels (NGs), characterized by their 3D network of crosslinked polymers, offer unique edges like high drug loading capacity, controlled release, and targeted delivery. Additionally, the diverse applications of NGs in medical therapeutics highlight their versatility and potential impact on improving patient outcomes. Their application spans cancer treatment, infectious diseases, and chronic conditions, allowing for precise drug delivery to specific tissues or cells, minimizing side effects, and enhancing therapeutic efficacy. Despite their potential, challenges such as scalability, manufacturing reproducibility, and regulatory hurdles must be addressed. Achieving clinical translation requires overcoming these obstacles to ensure therapeutic payloads' safe and efficient delivery. Strategies such as surface modification and incorporating stimuli-responsive elements enhanced NG performance and addressed specific therapeutic challenges. Advances in nanotechnology, biomaterials, and targeted drug design offer opportunities to improve the performance of NGs and address current limitations. Tailoring NGs for exploring combination therapies and integrating diagnostics for real-time monitoring represent promising avenues for future research. In conclusion, NG drug delivery systems have demonstrated tremendous potential in diverse disease applications. Overcoming challenges and leveraging emerging technologies will pave the way for their widespread clinical implementation, ushering in a new era of precision medicine and improved patient care.

Amino-functionalised mesoporous silica nanoparticles for the delivery of isoniazid and its metal complexes

The effective delivery of poor water-soluble anti-tubercular drugs such as isoniazid to their target sites is a major factor that has made it difficult for tuberculosis to be eradicated. Isoniazid derivatives and nano-particulate drug delivery systems are explored as one way to address this limitation. This study investigated the use of amino-functionalised mesoporous silica nanoparticles (MCM-41) as nano-carriers for the delivery of isoniazid-based metal complexes, Cu–INH and Fe–INH. The Sol-gel method was used to synthesise the nano-carriers, which produced a series of well-ordered nano-carriers. Their physicochemical properties were modified through surface functionalisation with amino groups via post-grafting synthesis. The isoniazid-based metal complexes were incorporated into the nano-carriers using rotary evaporation. The nano-carriers were characterised using X-ray diffraction (XRD), Zeta potential, Fourier Transmission Infra-red (FT-IR), Brunaeur Emmett Teller (BET), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Thermogravimetric analysis (TGA). These characterisation techniques confirmed the successful surface functionalisation of the nano-carriers with amino groups and their encapsulation with INH, Cu–INH and Fe–INH. The amino-functionalised nano-carriers were observed to have the highest drug loading capacities and entrapment efficiencies within the range of 7.85%–19.31 % and 39.26%–96.53 %, respectively. The release rates of INH, Cu–INH, and Fe–INH from the nano-carriers were also studied in Phosphate Buffer Solution (PBS) with pH of 7.4 and 5.4 using ultraviolet–visible spectroscopy. The cumulative release rates of INH, Cu–INH, and Fe–INH from their nano-carriers depended on their release media's textural properties and environmental conditions. Amino functionalised nano-carriers had high release rates, with A-MCM-41+Cu–INH having the highest of 37.09 % in PBS at 5.4 after 24 h. The cumulative data obtained was fitted into Zero order, First order, Hixson Crowell, Higuchi, Korsmeyer-Peppas and Weibull models. The Hixson Crowell, Korsmeyer-Peppas, and Weibull models fitted well with correlation coefficients (R2) of 0.9813, 0.9769 and 0.9802, respectively, for MCM-41+INH in PBS of pH 5.4.

A new intracellularly regulated release pattern controlled by coordinated carrier cracking and drug release

To further develop intracellular delivery systems of macromolecular drugs, understanding the cracking mechanisms and drug release behaviors of environment-responsive carriers, as well as their intrinsic linkages, is essential for achieving personalized or diversified delivery of macromolecular drugs. Herein, we designed a class of degradable dendritic mesoporous nanoparticles (DDMSNs), utilizing very large cavities and tetrasulfide bonds in the skeleton to achieve high drug loading and release within tumor cells. To comprehensively understand and develop intracellular drug delivery systems, this study delved deeper into the delivery of tetrasulfide-bonded DDMSNs, including chemical reactions, cracking kinetics, and release kinetics. First, the drug release of the DDMSNs within the cytoplasm was closely related to the chemical reaction of tetrasulfide bonds. Thus, based on experiments, the oxidation–reduction mechanism of tetrasulfide-bonded DDMSNs was explained, and the relationship was elaborated between cracking and drug release of the DDMSNs with different sulfur contents. To further explore this relationship, the cracking behavior, drug-loading capacity and release capacity of the DDMSNs was investigated with the different sulfur contents in different simulated environments, and in MDA-MB-231 cancer cells. Inspired by the reaction kinetic calculations, we analyzed the cracking and drug release behavior of the DDMSNs, and ultimately achieved dual cracking secondary drug release of the carriers by controlling the content of sulfur elements. Here, we report improved biomedical materials for advanced, customized, and intentional intracellular delivery of therapeutic macromolecules, in which theoretical calculations and experimental components were combined to study the mechanism of drug release influenced by carrier cracking, providing essential guidance for designing advanced drug delivery systems through a chemical engineering method.

Injectable Nanorobot-Hydrogel Superstructure for Hemostasis and Anticancer Therapy of Spinal Metastasis

HighlightsSite-selective superassembly was used to synthesize a nanorobot with bionic rod-shaped head/hollow tail structure, exhibiting strong photothermal effect, high drug loading capacity, precise and controlled drug release, and excellent motility.Injectable regenerated silk fibroin (RSF) nanofibril hydrogels were developed via simple sonication, offering significant production, structural, and performance advantages.Nanorobot/thrombin (Thr)/RSF nanofibril hydrogels reduced intraoperative bleeding of hepatocellular carcinoma (HCC) spinal metastasis, provided starvation embolization, and prevented post-surgery recurrence.Nanorobot/Thr/RSF nanofibril hydrogels inhibited blood supply to residual tumors and reduced neovascularization, inhibiting post-surgery HCC spinal metastasis recurrence.

Impact of Manual Addition of Vancomycin to Polymethylmethacrylate (PMMA) Cements.

(1) Background: The addition of antibiotics to bone cements is a common practice in the treatment of periprosthetic joint infections. In revision cases, the amount and type of antibiotic is often insufficient and additional antibiotics must be added. The addition, however, changes the product itself, and the surgeon becomes the "manufacturer" of the bone cement. PMMAe wished to clarify whether the admixture of antibiotics changes the mechanical stability of the bone cements used and if the added antibiotics were still functional and released in sufficient quantities. (2) Methods: We compared two industrially manufactured vancomycin-containing PMMA cements; the low-viscous VancogenX® (TECRES, Sommacampagna, Italy) and the high-viscous Copal® G+V (Heraeus Medical GmbH, Wehrheim, Germany), with two PMMA cements loaded with aminoglycosides, to which 2.0 g of vancomycin (Hexal CT1631) were manually added-the high-viscous Smartset® GHV and the medium-viscous Antibiotic Simplex with Tobramycin (antibiotic Simplex® T). Test specimens of the bone cements were used to determine mechanical stability (bending strength and bending module), and the release of the antibiotics was determined by HLPC and modified Kirby-Bauer assays. (3) Results: All tested bone cements showed an initial high release within the first hours. Repeated testing after 24 h showed a reduced efficacy of VancogenX® and Smartset® GHV in Kirby-Bauer assays. Long-time release over days showed a release of functional antimicrobial active ingredients over this period of time in anti-microbial assays, but no activity of VancogenX® from day 21 onward. No significant differences in the ISO bending modules could be detected, but in contrast to the bending module, the ISO bending strength was substantially reduced by 10-15 mPal in comparison to both cements of the reference group. The Simplex®T met just the ISO 5833; the Smartset® GHV did not after adding vancomycin. (4) Conclusions: In conclusion, the manual addition of 2 g of vancomycin to 40 g of PMMA powder is recommended for the treatment of methicillin-resistant staphylococci. Vancomycin is released over a period of 42 days with concentrations above the MIC for typical staphylococci. The mechanical properties of the PMMA just met, or did not fulfill, ISO mechanical specification. Copal® G+V showed a better elution than VancogenX® over time.

Development of Gentamicin Bilosomes Laden In Situ Gel for Topical Ocular Delivery: Optimization, In Vitro Characterization, Toxicity, and Anti-microbial Evaluation.

The eye drops are the prominent preparation used to treat surface eye disease (bacterial conjunctivitis). However, they have some limitations i.e., short corneal residence, resulting in low ocular bioavailability and necessitating frequent dose administration. The present study developed gentamicin (GE) bilosomes (BM)- laden in situ gel to improve therapeutic activity. The in situ gel system is initially in sol form before administration and converted into gel form in physiological eye conditions. The GE-BM was developed using the thin film hydration technique and optimized by D-optimal design. GE-BM was characterized for vesicle size, entrapment efficiency, zeta potential, morphology, and Fourier transform electron microscope (FTIR). The optimized GE-BM (GE-BMopt) was incorporated into an in situ gel and assessed for physicochemical characteristics. GE-BMopt in situ gel was evaluated for in vitro release, ex vivo permeation, toxicity, and antimicrobial study. GE-BMopt has a vesicle size of 185.1±4.8nm, PDI of 0.254, zeta potential of 27.6 mV, entrapment efficiency of 81.86±1.29 %, and spherical morphology. The FTIR study presented no chemical interactions between GE and excipients. GE-BMopt in situ gel (GE-BMoptIG4) showed excellent viscosity, gelling strength, and ex-vivo bio-adhesion. GE-BMopt-IG4 showed significant high and sustained release of GE (78.08±4.73% in 12h). GE-BMopt-IG4 displayed 3.27-fold higher ex-vivo goat corneal permeation than a pure GE solution. GE-BMopt-IG4 showed good corneal tolerance without any damage or irritation. GE-BMopt-IG4 showed significantly (P<0.05) higher anti-bacterial activity (ZOI) against Staphylococcus aureus and Escherichia coli than pure GE solution. The study determined that the BM in situ gel system can serve as a substitute carrier for GE to enhance its therapeutic effectiveness, and further preclinical studies are required.

Stellar Flares, Superflares, and Coronal Mass Ejections—Entering the Big Data Era

Flares, sometimes accompanied by coronal mass ejections (CMEs), are the result of sudden changes in the magnetic field of stars with high energy release through magnetic reconnection, which can be observed across a wide range of the electromagnetic spectrum from radio waves to the optical range to X-rays. In our observational review, we attempt to collect some fundamental new results, which can largely be linked to the Big Data era that has arrived due to the expansion of space photometric observations over the last two decades. We list the different types of stars showing flare activity and their observation strategies and discuss how their main stellar properties relate to the characteristics of the flares (or even CMEs) they emit. Our goal is to focus, without claiming to be complete, on those results that may, in one way or another, challenge the “standard” flare model based on the solar paradigm.

PTFE-modified Al through bridging approach to enhance combustion reaction and energetic performance

Aluminum/Polytetrafluoroethylene (Al/PTFE) composites have attracted a great deal of attention due to their remarkable energy density and wide range of applications. Unfortunately, the inert oxide layer (Al2O3) on the surface of Al and the interfacial contact area between PTFE and Al seriously impact the combustion reaction kinetics and energy output efficiency. Here, an approach is utilized to significantly enhance the interfacial contact area between Al and PTFE through F2601 serving as the bridging agent. The ignition, combustion reaction, and energetic performance (pressure and combustion heat) can be adjusted by varying the particle size of Al and PTFE content. The energy release efficiency of bridging Al/PTFE has been improved significantly as PTFE content increases and the particle size of Al decreases. The bridging Al/PTFE with 10 μm Al and nano Al exhibit a bright and wide flame, and a fierce flame propagation process, as well as much high pressure output (167.73 kPa and 199.92 kPa) and heat release (11879 J/g and 12322 J/g). Furthermore, the critical mass ratio (approximately 88/12) of bridging Al/PTFE for self-sustained combustion has been obtained for the first time. The improvement of energy output performance is attributed to the interfacial contact between PTFE and Al and the reaction of fluorine and Al2O3 resulted from bridging Al/PTFE through F2601. The prepared bridging Al/PTFE with high energy output characteristics holds great potential in solid propellants, reactive materials, and other high-energy fuels.

Comparative Evaluation of Zwitterionic Material, Self-assembling Peptide, and Bioactive Glass Incorporated with MI Varnish for Fluoride, Calcium, and Phosphorus Ion Release, Enamel Remineralization, and Microhardness.

White spot lesions occur when the pathogenic bacteria have broken through the enamel layer. White spot lesions (WSLs) can be treated using a complex approach. The most crucial step is to stop demineralization and biofilm formation and use assorted strategies for remineralization of lesions, thinning, microabrasion, erosion infiltration, adhesive composite resin restorations, and the bonded facets. To evaluate and compare the fluoride, calcium, and phosphorus ion release, remineralizing efficacy, and microhardness of zwitterionic material, self-assembling peptide, and bioactive glass (BGA) incorporated with MI Varnish. The original study was conducted on 60 extracted premolars; the sample size calculated was 10 per group. All samples were divided into four groups-group A, MI Varnish (control), group B, MI Varnish + zwitterionic material, group C, MI Varnish + self-assembling peptide, and group D, MI Varnish + BGA. All these groups were further evaluated and compared for fluoride, calcium, and phorphorus ion release, remineralizing efficacy, and surface microhardness (SMH). Zwitterionic material, when incorporated with MI Varnish showed high fluoride and calcium ion release and high remineralizing efficacy under polarized light microscopy (PLM). BGA, when incorporated with MI Varnish showed high phosphorus ion release and higher values in the evaluation of SMH, followed by zwitterionic material and self-assembling peptide. MI varnish alone had remineralizing properties of WSLs, but when novel materials like zwitterionic ion, self-assembling peptide, and BGA are incorporated, its efficacy increases. Among all zwitterionic ions showed superior results for fluoride and calcium ion release and remineralization and BGA for phosphorus ion release and SMH. Patil SV, Gugwad SC, Devendrappa SN, et al. Comparative Evaluation of Zwitterionic Material, Self-assembling Peptide, and Bioactive Glass Incorporated with MI Varnish for Fluoride, Calcium, and Phosphorus Ion Release, Enamel Remineralization, and Microhardness. Int J Clin Pediatr Dent 2024;17(S-1):S37-S42.

Sustained release of stem cell secretome from nano-villi chitosan microspheres for effective treatment of atopic dermatitis

Canine atopic dermatitis (AD) arises from hypersensitive immune reactions. AD symptoms entail severe pruritus and skin inflammation, with frequent relapses. Consequently, AD patients require continuous management, imposing financial burdens and mental fatigue on pet owners. In this study, we aimed to investigate the therapeutic relevance of secretome from canine adipose tissue-derived mesenchymal stem cells (MSCs), especially after encapsulation in nano-villi chitosan microspheres (CS-MS) to expect improved efficacy. Conditioned media (CM) from MSCs significantly inhibited the proliferation of splenocytes, induced the generation of regulatory T cells, and decreased mast cell degranulation. We found that beneficial soluble factors known to reduce AD symptoms, including transforming growth factor-beta 1, were detectable after sequential concentration and lyophilization of CM. The CS-MS, developed by a phase inversion regeneration method, showed high loading and sustained release of the secretome. Local injection of secretome-loaded CS-MS (ST/SC-MS) effectively reduced clinical severity compared to groups treated with secretome. Histological analysis revealed that ST/SC-MS potently suppressed epidermal hyperplasia, immunocyte infiltration and mast cell activation in the lesion. Taken together, this study presents a novel therapeutic approach exhibiting more potent and prolonged immunoregulatory efficacy of MSC secretome for canine AD treatment.

Optimization of microgrid operations using renewable energy sources

Microgrids, comprising localized energy systems capable of operating independently or in conjunction with the main grid, are increasingly being recognized as vital components of modern energy infrastructure. The integration of renewable energy sources (RES) into microgrids offers significant potential for enhancing operational efficiency, sustainability, and resilience. This paper presents an overview of recent advancements and methodologies for optimizing microgrid operations utilizing renewable energy sources. The optimization of microgrid operations involves the strategic coordination and management of diverse energy resources, including solar photovoltaic (PV) systems, wind turbines, and energy storage systems (ESS). Key objectives include minimizing operational costs, reducing greenhouse gas emissions, ensuring reliable power supply, and maintaining system stability. Advanced optimization techniques, such as model predictive control (MPC), mixed-integer linear programming (MILP), and heuristic algorithms, play a crucial role in achieving these objectives by enabling the dynamic adjustment of energy generation and distribution in response to real-time conditions. A critical aspect of microgrid optimization is the accurate forecasting of renewable energy generation and load demand. Machine learning (ML) and artificial intelligence (AI) algorithms have been effectively employed to enhance prediction accuracy, thereby improving decision-making processes. Furthermore, the integration of ESS, such as batteries and flywheels, helps to address the intermittency of RES, providing a buffer that can store excess energy during periods of high generation and release it during peak demand. The implementation of demand response (DR) strategies within microgrids further contributes to optimization efforts. By incentivizing consumers to adjust their energy usage patterns in response to price signals or grid needs, DR programs help to balance supply and demand, reduce peak loads, and enhance overall grid reliability. Case studies and field implementations demonstrate the practical benefits of optimized microgrid operations. For instance, microgrids incorporating high shares of RES have been shown to achieve significant cost savings, improved energy security, and reduced environmental impacts. These successes underline the importance of ongoing research and development in optimization techniques and the need for supportive policy frameworks to facilitate the broader adoption of microgrids. In conclusion, optimizing microgrid operations using renewable energy sources presents a promising pathway toward a more sustainable and resilient energy future. Continued advancements in optimization algorithms, predictive analytics, and integrated system design are essential for unlocking the full potential of microgrids, ensuring they can effectively meet the evolving energy demands and environmental challenges of the 21st century. Keywords: Optimization, Microgrid, Operations, Renewable Energy, Energy Sources.

In-situ forming Cu-based metal-organic framework in the presence of chitosan-Fe3O4 nanohybrids: A pH-sensitive carrier for controlled release of doxorubicin

In recent years, stimuli-responsive drug delivery systems based on pH, particularly those developed using bio-derived nanocomposite systems, have gained significant attention. In this work, a novel magnetic carrier was designed based on biopolymeric chitosan and metal-organic framework (MOF) for pH-controlling the release of anticancer drugs. To end this, an in-situ green method was performed to form Cu-based MOF in the presence of a magnetic polysaccharide synthesized by precipitation method toward the construction of CS/Fe3O4/Cu-MOF nanocomposite. The nanocomposite was immersed in an aqueous solution of a model anticancer drug, doxorubicin (DOX), and a higher loading capacity (90.1 ± 0.5 %) was achieved. The in-vitro drug release study showed low release rates in simulated physiological environments (pH 7.4, 37 °C, lower than about 20 %), but higher release rates in tumor tissue conditions (pH 4.5, 41 °C, higher than about 60 %) over 96 h, allowing for sustained and extended delivery of DOX. Additionally, the MTT assay demonstrated that the blank and DOX-loaded CS/Fe3O4/Cu-MOF had good cytocompatibility (over 80 % cell viability) and considerable cytotoxicity (lower than 40 % at 16 μg/mL) toward breast cancer (MCF-7) cell line, respectively. These results indicated that the synthesized nanocomposite with suitable pH-sensitivity has potential as a targeted anticancer agent.

Expanding the Design Space of Polymer-Metal Organic Framework (MOF) Gels by Understanding Polymer-MOF Interactions.

The fabrication of polymer-MOF composite gels holds great potential to provide emergent properties for drug delivery, environmental remediation, and catalysis. To leverage the full potential of these composites, we investigated how the presence and chemistry of polymers impact MOF formation within the composites and, in turn, how MOFs impact polymer gelation. We show that polymers with a high density of strongly metal-binding carboxylic acids inhibit MOF formation; however, reducing the density of carboxylic acids or substituting them with weaker metal-binding hydroxyl groups permits both MOF formation and gelation within composites. Preparing composites with poly(ethylene glycol) (PEG), which does not bind MOF zirconium (Zr)-oxo clusters, and observing gelation suggests that MOFs can entrap polymer chains to create cross-links in addition to cross-linking them through polymer-Zr-oxo interactions. Both simulations and experiments show composite hydrogels formed with poly(vinyl alcohol) (PVA) to be more stable than those made with PEG, which can reptate through MOF pores upon heating. We demonstrate the generalizability of this composite formation process across different Zr-based MOFs (UiO-66, NU-901, UiO-67, and MOF-525) and by spin-coating gels into conformable films. PVA-UiO-66 composite hydrogels demonstrated high sorption and sustained release of methylene blue relative to the polymer alone (3× loading, 28× slower release), and PVA-MOF-525 composite hydrogels capably sorb the therapeutic peptide Angiotensin 1-7. By understanding the influence of polymer-MOF interactions on the structure and properties of composite gels, this work informs and expands the design space of this emerging class of materials.

Physicochemical characterization of experimental resin-based materials containing calcium orthophosphates or calcium silicate

ObjectiveTo evaluate experimental dimethacrylate-based materials containing calcium orthophosphates or calcium silicate particles in terms of their optical, mechanical and Ca2+ release behaviour. MethodsDicalcium phosphate dihydrate (DCPD), hydroxyapatite (HAp), beta-tricalcium phosphate (β-TCP) or calcium silicate (CaSi) particles were added to a photocurable BisGMA/TEGDMA resin (1:1 in mols) at a 30 vol% fraction. Materials containing silanized or non-silanized barium glass particles were used as controls. Degree of conversion (DC) at the top and base of 2-mm thick specimens was determined by ATR-FTIR spectroscopy (n = 5). Translucency parameter (TP) and transmittance (%T) were determined using a spectrophotometer (n = 3). Biaxial flexural strength (BFS) and flexural modulus (FM) were determined by biaxial flexural testing after 24 h storage in water (n = 10). Ca2+ release in water was determined during 28 days by inductively coupled plasma optical emission spectrometry (n = 3). Statistical analysis was performed using ANOVA/Tukey test (DC: two-way; TP, %T; BFS and FM: one-way; Ca2+ release: repeated measures two-way, α = 5 %). Results: CaSi and β-TCP particles drastically reduced DC at 2 mm, TP and %T (p < 0.001). Compared to both controls, all Ca2+-releasing materials presented lower BFS (p < 0.001) and only the material with DCPD showed significantly lower FM (p < 0.05). The material containing CaSi presented the highest Ca2+ release, while among materials formulated with calcium orthophosphates the use of DCPD resulted in the highest release (p < 0.001). SignificanceCaSi particles allowed the highest Ca2+ release. Notwithstanding, the use of DCPD resulted in a material with the best compromise between optical behaviour, DC, strength and Ca2+ release.

High-efficient M-NC single-atom catalysts for catalytic ozonation in water purification: Performance and mechanisms

Heterogeneous catalytic ozonation (HCO) holds promise in water purification but suffers from limited accessible metal sites, metal leaching, and unclear structure-activity relationships. This work reported M-NC (M=Co, Ni, Fe, and Mn) single-atom catalysts (SACs) with high atomic efficiency and minimal metal release. The new HCO systems, especially the Co-based system, exhibited impressive performance in various refractory contaminant removal, involving various reactive species generation, such as •OHads, •OHfree, *O, and 1O2. For sulfamethoxazole removal, the normalized kobs for Co-NC, Ni-NC, Fe-NC, and Mn-NC were determined as 13.53, 3.94, 3.55, and 4.13 min−1·mMmetal−1·g·m−2 correspondingly, attributed to the abundant acid sites, faster electron transfer, and lower energy required for O3 decomposition and conversion. The metal atoms and hydroxyl groups, individually serving as Lewis and Bronsted acid sites (LAS and BAS), were the primary centers for •OH generation and O3 adsorption. The relationships between active sites and both O3 utilization and •OH generation were found. LAS and BAS were responsible for O3 adsorption, while strong LAS facilitated O3 conversion into •OH. Theoretical calculations revealed the catalytic mechanisms involved O3→ *O→ *OO→ O3•−→ •OH. This work highlights the significance of SAC design for HCO and advances the understanding of atomic-level HCO behavior.

Topical amlodipine-loaded solid lipid nanoparticles for enhanced burn wound healing: A repurposed approach

Burn wounds are a complicated process with ongoing psychological and physical issues for the affected individuals. Wound healing consists of multifactorial molecular mechanisms and interactions involving; inflammation, proliferation, angiogenesis, and matrix remodeling. Amlodipine (ADB), widely used in cardiovascular disorders, demonstrated antioxidant and anti-inflammatory effects in some non-cardiovascular studies. It was reported that amlodipine is capable of promoting the healing process by regulation of collagen production, extracellular matrix, re-epithelialization and wound healing through its vasodilation and angiogenic activity. The objective of the current study is to appraise the wound healing capacity of amlodipine-loaded SLN (ADB-SLN) integrated into a hydrogel. The in-vitro characterization revealed that the optimized formulation was nanometric (190.4 ± 1.6 nm) with sufficiently high entrapment efficiency (88 % ± 1.4) and sustained ADB release (85.45 ± 4.45 % after 12 h). Furthermore, in-vivo evaluation was conducted on second-degree burns induced in male Sprague-Dawley rats. ADB-SLN gel revealed a high wound contraction rate and a significant improvement in skin regeneration and inflammatory biomarkers levels, confirming its efficiency in enhancing wound healing compared to other tested and commercial formulations. To conclude, the present findings proved that ADB-SLN integrated hydrogel offers a promising novel therapy for burn wound healing with a maximum therapeutic value.