Search Results (158)

To achieve stable dispersion of ZnO nanoparticles in the base fluid and enhance thermal conductivity (λ), a PGPR@ZnO nano-hyperdispersant was synthesized using polyglycerol polyricinoleate (PGPR) and ZnO. FT-IR and DSC confirmed the bonding interaction between PGPR and ZnO, and zeta potential analysis verified the steric hindrance effect that effectively inhibits particle agglomeration. The PGPR@ZnO was dispersed into di(2-ethylhexyl) carbonate (DEHC) by ultrasonication and stirring, yielding a stable DEHC-PGPR@ZnO nanofluid. This nanofluid achieved a 16.2% increase in λ while retaining the low viscosity and low pour point of the base fluid. Stability assessments showed consistent particle size main peaks before and after static and dynamic tests, with no obvious agglomeration peaks, average particle size variation below 6%, PDI below 0.3, and negligible zeta potential fluctuation. Following static and dynamic stability tests, the thermal conductivity decreased by 0.85% and 7.98%, respectively. These results indicate excellent dispersion stability and provide a valuable reference for evaluating the operational adaptability of the coolant. The nanofluid meets the basic standards for immersion coolants and exhibits a figure of merit (FOM) superior to most oil-based coolants. Compared with PAO2, it offers advantages in raw material availability and resistance to hydrolysis and acidification, providing research and practical foundation for the development of high-performance immersion coolants. Full article

Ventricular septal defect (VSD) occluders commonly rely on permanent nitinol frameworks, which may contribute to long-term mechanical mismatch and late complications. Here, we developed a tissue-compliant composite membrane by embedding a 3D-printed poly(vinyl alcohol) (PVA) grid within a shape-memory poly(glycerol dodecanedioate) (PGD) matrix. Grid spacing was varied from 0.1 to 0.5 mm to tune reinforcement density. FTIR indicated that PVA was incorporated mainly through physical interlocking rather than new covalent bonding. The composite preserved near-body-temperature shape recovery. In water at 37 °C, PVA reinforcement increased tensile modulus and fracture strength, although swelling also increased. Finite-element analysis and benchtop occlusion testing consistently showed lower deformation, less strain localization, and smaller bulge height for PGD–PVA than for PGD alone. In vitro assays showed low cytotoxicity, low hemolysis, and prolonged plasma recalcification time. A 12-week pilot degradation study showed that the faster mass loss observed in initial samples was mainly caused by exposed PVA cut edges; after switching to a fully encapsulated design, static mass loss became similar across groups, and dynamic PBS agitation produced about 10% mass loss at 12 weeks. These results support PGD–PVA as a reinforced membrane strategy for polymeric occluders. Full article

Background/Objectives: The development of stimuli-responsive hydrogels for biomedical uses is an intense field of research. The use of dendritic crosslinkers can enhance the control over the structure and properties of the networks. This work presents a comparative study on the design and evaluation of Pluronic L35 thermogels, incorporating either hydrophobic carbosilane dendrimers (CBS, generations 1 to 3) or hydrophilic dendritic polyglycerols (dPG, 10 k) as crosslinkers. Methods: The thermogels were synthesized via UV-initiated thiol–ene click chemistry. Additionally, they were characterized through swelling studies, mechanical properties, degradation kinetics as well as loading and release studies of the antitumor drug doxorubicin as poorly soluble model cargo. Results: The incorporation of dendritic crosslinkers allowed higher control over the crosslinking process, while the amphiphilic polymer imparted temperature-responsive properties to the resulting networks. Remarkable differences were observed in swelling behavior, mechanical properties and degradation kinetics, depending on the nature of the dendritic crosslinker. Additionally, regarding doxorubicin loading and release in water, CBS hydrogels produced a sustained release over one week, led by network swelling, while dPG hydrogels exhibited a burst release in 4–24 h but were limited by the stronger interaction of DOX with the dPG scaffold. Conclusions: The study provided useful insight for the tailoring of dendritic thermogels for specific biomedical uses such as controlled drug delivery. Full article

Poly(glycerol sebacate) (PGS) is a biodegradable elastomer with high potential for tissue engineering. However, its limited structural stability and degradation control restrict broader biomedical applications. This study presents an integrated fabrication strategy for highly porous PGS-IPDI scaffolds reinforced with two types of hydroxyapatite of distinct origin (HAP_B and HAP_ICMB). By combining low-temperature urethane crosslinking with thermally induced phase separation and salt leaching, we obtained scaffolds with interconnected micro–macroporous architectures and exceptionally high porosity (up to 98%). The comparative incorporation of phase-pure nanometric HAP_B and biphasic HAP_ICMB enabled the identification of composition-dependent differences in water uptake, structural stability, and mineralization tendencies. Furthermore, degradation behavior was systematically evaluated in four physiologically relevant media (PBS, SBF, artificial saliva, Ringer’s solution), revealing distinct degradation pathways associated with each environment. The results provide new insight into how hydroxyapatite type and incubation medium collectively govern the long-term performance of chemically crosslinked PGS-based scaffolds. Full article

The polyglycerol esters (PGEs) of fatty acids have a wide range of HLB values and applications in diverse industries, such as pharmaceuticals and cosmetics. While the physicochemical properties of oil-soluble PGEs dissolved in oil phases are well studied in the literature, there is no information on their structuring in aqueous phases and emulsifying abilities. We combined rheological and differential scanning calorimetry (DSC) measurements and microscopy observations to characterize the dependence of oil-soluble PGE structuring in aqueous phases on the PGE concentration, the temperature of solution homogenization, and the PGE molecular structure. Excellent correlations between the considerable changes in solution viscosity and the temperatures of the two endo- and exothermic peaks in the DSC thermograms are observed. Single-tail PGE molecules, which have a higher number of polyglycerol units, are better organized in networks, and the viscosity of their aqueous solutions is higher compared to that of the respective double-tail PGE molecules. PGEs exhibit good emulsifying ability and the viscosity of the produced emulsions at room temperature can differ by orders of magnitudes depending on the temperature of emulsification. The reported properties of oil-soluble PGEs could be of interest for increasing the range of their applicability in practice. Full article

Gadolinium (Gd)-based nanomaterials have attracted a considerable amount of attention in cancer treatment research due to their applicability in radiotherapy. However, the clinical translation of Gd-based nanomaterials is limited by their high density and poor dispersibility in aqueous media, thereby necessitating surface functionalization with biocompatible polymers. In this study, gadolinium tungstate (Gd₂(WO₄)₃) nanoflakes (GW Nfs) were functionalized with poly(glycerol) (PG) to enhance their dispersibility and stability in aqueous media. Due to their high-Z elemental composition, the GW Nfs generated reactive oxygen species (ROS) under X-ray irradiation, with improved dispersibility induced by PG functionalization further enhancing ROS productivity compared to GW Nfs. Furthermore, PG-GW loaded with the photosensitizer chlorin e6 (Ce6) demonstrated strong photocytotoxicity at Ce6 concentrations as low as 0.2 μg mL⁻¹ under light irradiation. Taken together, these results demonstrate that PG-GW/Ce6 is a promising nanomaterial for photodynamic therapy while also offering prospects for bimodal photon cancer therapy with X-rays. Full article

High Mobility Group Box 1 (HMGB1) is a central pro-inflammatory mediator released from damaged or stressed cells, where it activates receptors such as the Receptor for Advanced Glycation Endproducts (RAGE). Dendritic polyglycerol sulfate (dPGS), a hyperbranched polyanionic polymer, is known for its anti-inflammatory activity. In this study, we examined how dPGS modulates HMGB1-driven signaling in RAW 264.7 macrophages and human microglia. Recombinant human HMGB1 expressed in Escherichia coli (E. coli) was purified by nickel-nitrilotriacetic acid (Ni-NTA) and heparin chromatography. Proximity ligation assays (PLA) revealed that dPGS significantly disrupted HMGB1/RAGE interactions, particularly under lipopolysaccharide (LPS) stimulation, thereby reducing inflammatory signaling complex formation. This correlated with reduced activation of the nuclear factor kappa B (NF-κB) pathway, demonstrated by decreased nuclear translocation and transcriptional activity. Reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR (RT-qPCR) showed that dPGS suppressed HMGB1- and LPS-induced transcription of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). Enzyme-linked immunosorbent assay (ELISA) and Griess assays confirmed reduced TNF-α secretion and nitric oxide production. Electron paramagnetic resonance (EPR) spectroscopy further showed that dPGS altered HMGB1/soluble RAGE (sRAGE) complex dynamics, providing mechanistic insight into its receptor-disruptive action. Full article

Additive manufacturing (AM) demands materials that combine precise printability with reliable thermal and mechanical performance. Polyglycerol (PG)-based macromolecular systems offer exceptional tunability through controlled architecture and chemical modification, enabling their use across both light-based and extrusion AM platforms. Strategic enhancements such as chemical functionalization, network formation, and hybrid reinforcement have expanded their capabilities from biomedical to structural applications, delivering improved stability, strength, and functionality. Despite these advances, performance-processing trade-offs and dispersion challenges remain barriers to widespread adoption. This review synthesizes current knowledge on PG-based materials in AM, mapping key structure-property-processing relationships and identifying strategies to advance their development as versatile and sustainable options for next-generation manufacturing. Full article

This study proposes a dual-approach strategy to formulate reduced-fat milk chocolate by combining cocoa butter (CB) substitution with emulsifier-based rheological optimization. CB was partially replaced at 20%, 30%, and 40% using whey protein isolate (WPI) and inulin (IN) blends (70:30, 50:50, 30:70 w/w). CB reduction increased plastic viscosity and yield stress, particularly in WPI-rich systems. The 50:50 WPI:IN ratio consistently minimized rheological drawbacks while maintaining melting, texture, and sensory quality. Caloric content was reduced by up to 9% (~50 kcal/100 g), most notably in IN-dominant samples. To overcome flow challenges at high substitution levels, emulsifiers—lecithin, ammonium phosphatide (AMP), and polyglycerol polyricinoleate (PGPR)—were assessed. AMP (≤0.5% w/w) and PGPR (0.15–0.3% w/w) effectively reduced viscosity and yield stress; lecithin showed limited effect above 0.6%. The optimized system (0.5% AMP + 0.15% PGPR) applied to 40% CB-reduced chocolate with 50:50 WPI:IN restored desirable rheology (3.42 Pa·s viscosity; 7.91 Pa yield stress) and improved mouthfeel and acceptability. This integrated formulation enables significant fat and calorie reduction without compromising product quality, supporting the development of healthier chocolate products. Full article

A chemical platform for post-polymerization methods was developed, starting from the ecodesign and enzymatic synthesis of safe and sustainable bio-based polyesters containing discrete units of itaconic acid. This unsaturated bio-based monomer enables the covalent linkage of molecules that can impart desired properties such as hydrophilicity, flexibility, permeability, or affinity for biological targets. Molecular descriptor-based computational methods, which are generally used for modeling the pharmacokinetic properties of drugs (ADME), were employed to predict in silico the hydrophobicity (LogP), permeability, and flexibility of virtual terpolymers composed of different polyols (1,4-butanediol, glycerol, 1,3-propanediol, and 1,2-ethanediol) with adipic acid and itaconic acid. Itaconic acid, with its reactive vinyl group, acts as a chemical platform for various post-polymerization functionalizations. Poly(glycerol adipate itaconate) was selected because of its higher hydrophilicity and synthetized via solvent-free enzymatic polycondensation at 50 °C to prevent the isomerization or crosslinking of itaconic acid. The ecotoxicity and marine biodegradability of the resulting oligoester were assessed experimentally in order to verify its compliance with safety and sustainability criteria. Finally, the viability of the covalent linkage of biomolecules via Michael addition to the vinyl pendant of the oligoesters was verified using four molecules bearing thiol and amine nucleophilic groups: N-acetylcysteine, N-Ac-Phe-ε-Lys-OtBu, Lys-Lys-Lys, and glucosamine. Full article

Clove oil is an essential oil used in food and pharmaceutical applications, with a market value of 300+ million dollars per year. Microemulsions have been used as effective clove oil delivery vehicles and could also be used to develop new extraction processes from clove buds. Eugenol, the main component of clove oil, is a polar oil that behaves as a surfactant and as an oil. This bifunctional behavior makes formulating clove oil microemulsions a challenging task. Here, we used a version of the Hydrophilic–Lipophilic Difference (HLD) + Net-Average Curvature (NAC) model that incorporates the bifunctional polar oil model to predict and fit the phase behavior of lecithin (surfactant) + polyglycerol-10 caprylate (hydrophilic linker) microemulsions using mixtures of heptane and clove oil as the oil phase. Using HLD-NAC parameters from the literature, the predicted HLD-NAC curves reproduced the expected phase transitions and the trends in Eugenol segregation toward the surfactant layer. Using these literature parameters as an initial guess to fit the experimental phase volumes produced accurate calculated phase volumes, and predicted interfacial tensions. This work demonstrates the application of heuristics and databases of HLD-NAC parameters in predicting the complex phase behavior of surfactant–oil–water (SOW) systems. Full article

Processes using CO₂ either as a solvent or as a reactant, for example, in catalyzed chemical reactions, are increasing in interest due to their green characteristics. Hyperbranched polyglycerols have the potential to be used as support for catalysts in these processes, allowing for an efficient separation of the products and the reutilization of the catalyst, but this requires them to absorb CO₂. Acetylating hydroxylated compounds has shown to be an efficient way to increase their CO₂-philicity, and this work aims to understand how acetylation increases the interaction of hyperbranched polyglycerols with different cores with supercritical CO₂. This involves the study of their kinetics of expansion in this media (from 10 to 25 MPa and at 35 °C and 45 °C) and, eventually, their solubility when it happens. The expansion of the acetylated polyglycerols reached up to 66% in volume, while that of non-acetylated ones, in general, do not exceed 10%. Acetylation plays an important role in increasing the expansion of these polymers in the presence of CO₂ and, therefore, in increasing their CO₂-philicity and CO₂ absorption, making them potential materials to be used in biphasic (polymer/CO₂) reaction systems. Full article

The development of biodegradable nanocarriers has long been a priority for researchers and medical professionals in the realm of drug delivery. Because of their inherent benefits, which include superior biocompatibility, customizable degradability, easy surface functionalization, and stealth-like behavior, polylactic acid-hyperbranched polyglycerol (PLA-HPG) copolymers have demonstrated a promising future in the field of biomedical research. The synthesis of PLA-HPG copolymers and the creation of their nanoparticles for biomedical uses have been the focus of current efforts. In this review, we summarize the synthetic strategies of PLA-HPG copolymers and corresponding nanoparticles, and highlight their physicochemical properties, biocompatibility, and degradation properties. Furthermore, we introduce a number of PLA-HPG nanoparticles that are utilized for surface skin delivery, wound dressing, and in vivo drug delivery biological applications. Finally, we conclude by offering our thoughts on how this nanoplatform might advance in the future. Full article

This study aims to provide a comprehensive evaluation of the bioactive compounds present in honeysuckle flower (Lonicera japonica Thunb.) extract (HSF) and their remarkable antioxidant activity. A docking simulation was performed to clarify the binding affinities of the identified phytochemicals to enzymes associated with anti-aging and anti-inflammatory activities. In addition, the low-energy nanoemulsions based on optimally formulated polyglycerol fatty acid esters (PGFEs), developed through D-optimality, were designed for the incorporation of HSF extract. The result revealed that HSF is a rich source of diverse phenolic and flavonoid compounds that contribute to its remarkable antioxidant capacity. Molecular docking analysis indicates that its compounds exhibit anti-aging and anti-inflammatory activities, particularly through collagenase, hyaluronidase, and TNF-α inhibition. Furthermore, D-optimality revealed that HSF-loaded nanoemulsions can be fabricated by a surfactant to oil ratio (SOR) of 2:1 with a ratio of low hydrophilic-lipophilic balance (HLB) surfactant to high HLB surfactant (LHR) of 1:2. Polyglyceryl-6 laurate as a high HLB surfactant produced the optimal nanoemulsion with small particle size and possessed an encapsulation efficiency (EE) of 74.32 ± 0.19%. This is the first report to combine D-optimal design-based nanoemulsion development with a multi-level analysis of HSF, including phytochemical profiling, antioxidant evaluation, and in silico molecular docking. These findings highlight that HSF-loaded polyglycerol fatty acid ester-based nanoemulsions could be a skin health-promoting ingredient and effective alternative for a variety of skincare applications. Full article

Delivering of hydrophobic drugs by polymeric nanoparticles is an intensively investigated research and development field worldwide due to the insufficient solubility of many existing and potential new drugs in aqueous media. Among polymeric nanoparticles, micelles of biocompatible amphiphilic block copolymers are among the most promising candidates for solubilization, encapsulation, and delivery of hydrophobic drugs to improve the water solubility and thus the bioavailability of such drugs. In this study, amphiphilic ABA triblock copolymers containing biocompatible hydrophilic hyperbranched (dendritic) polyglycerol (HbPG) outer and hydrophobic poly(tetrahydrofuran) (PTHF) inner segments were synthesized using amine-telechelic PTHF as a macroinitiator for glycidol polymerization. These hyperbranched–linear–hyperbranched block copolymers form nanosized micelles with 15–20 nm diameter above the critical micelle concentration. Coagulation experiments proved high colloidal stability of the aqueous micellar solutions of these block copolymers against temperature changes. The applicability of block copolymers as drug delivery systems was investigated using curcumin, a highly hydrophobic, water-insoluble, natural anti-cancer agent. High and efficient drug solubilization up to more than 3 orders of magnitude to that of the water solubility of curcumin (>1500-fold) is achieved with the HbPG-PTHF-HbPG block copolymer nanomicelles, locating the drug in amorphous form in the inner PTHF core. Outstanding stability of and sustained curcumin release from the drug-loaded block copolymer micelles were observed. The in vitro bioactivity of the curcumin-loaded nanomicelles was investigated on U-87 glioblastoma cell line, and an optimal triblock copolymer composition was found, which showed highly effective cellular uptake and no toxicity. These findings indicate that the HbPG-PTHF-HbPG triblock copolymers are promising candidates for advanced drug solubilization and delivery systems. Full article