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Graphene quantum dots nanoparticles changed the rheological properties of hydrophilic gels (carbopol)
摘要： Graphene quantum dots (GQDs) have special properties at nanosize zone, as highly tunable photoluminescence, electrochemiluminescence and multiphoton excitation, that make them promising nanoagents for drug delivery systems. In this direction the use of gels to formulate nanodrugs, for both in vitro and in vivo assay is required. However, the presence of GQDs nanoparticles may affect the rheological parameters. These changes may influence the biological behavior of this formulation as change the pharmacological application. In this study we evaluated the effect of adding GQDs to carbopol gels formulation, in terms of rheological properties. In this direction, carbopol gels alone and loaded with GQDs were studied. The results of pure carbopol formulation showed a non-Newtonian, pseudo-plastic fluid without thixotropic behavior. Otherwise, the presence of GQDs in the carbopol formulation (carbopol loaded with GQDs) caused a reduction on the viscosity and modified the interactions between the polymer chains leading to the transformation of the initial gel into a viscous fluid. This alteration can change drastically the use of these formulations, especially for drug delivery, since slightly changes in viscosity can influence the occlusion, retention and permeability of these nanoparticles into biological barriers.
关键词： Rheological properties,Drug delivery,Graphene quantum dots,Hydrogels,Carbopol
更新于2025-11-19 16:56:42
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NIR light-triggered gelling <i>in situ</i> of porous silicon nanoparticles/PEGDA hybrid hydrogels for localized combinatorial therapy of cancer cells
摘要： Porous silicon-based nanocomposite hydrogels were readily constructed with the gelation of poly(ethylene glycol) double acrylates (PEGDA) macromers, due to the initiation of singlet oxygen photosensitized with porous silicon nanoparticles (PSiNPs) under near-infrared (NIR) light irradiation. Multifunctional PSiNPs/PEGDA nanocomposite hydrogels showed strong ?uorescence, excellent biodegradability, signi?cant photothermal effect, and sustained drug release with high ef?ciency (>80%). Finally, in situ growth of PSiNPs/PEGDA hybrid hydrogels on cancer cells was also achieved by NIR light, and then their biodegradation, drug release and synergistic chemo-phototherapeutic ef?cacy were further demonstrated, which could provide a signi?cant localized inhibition for the viability, adherence, and migration of cancer cells in vitro. Thus, we suggested that these resultant hybrid hydrogels would have important potential on local cancer therapy in future clinical practice.
关键词： porous silicon nanoparticles,hybrid hydrogels,therapy,insitu gelation,localized cancer
更新于2025-09-23 15:23:52
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Surface-Initiated Metal-Free Photoinduced ATRP of 4-Vinylpyridine from SiO2 via Visible Light Photocatalyst for Self-healing Hydrogels
摘要： Robust and self-healable nanocomposite hydrogels was realized by the encapsulation of components of photoinduced electron transfer-atom transfer radical polymerization (PET-ATRP) into the surface-modified silica nanoparticles (SiO2). The prepared SiO2@P4VP was in the form of self-healing nanocomposite hydrogels, where 4-Vinylpyridine (4VP) was polymerized through PET-ATRP with organic photocatalyst Rhodamine B. The modified nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). The nanocomposite hydrogels can be healed rapidly and autonomously without any stimulation at ambient temperature. Specifically, the nanocomposite hydrogels has a tensile strength of about 2.90 MPa, which recovered to 77.0% after 12 hours, and an elongation at break of about 730 %. These self-healing hydrogels with cheap raw material, possess better strength and self-healing performance, will have broad prospects.
关键词： Self-Healing Hydrogels,Visible Light,Metal-Free Photoinduced ATRP,Nanocomposite Hydrogels
更新于2025-09-23 15:21:21
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Multifunctional Nanoparticle Loaded Injectable Thermoresponsive Hydrogel as NIR Controlled Release Platform for Local Photothermal Immunotherapy to Prevent Breast Cancer Postoperative Recurrence and Metastases
摘要： For breast cancer patients who have undergone breast-conserving surgery, effective treatments to prevent local recurrences and metastases is very essential. Here, a local injectable therapeutic platform based on a thermo-sensitive PLEL hydrogel with near-infrared (NIR)-stimulated drug release is developed to achieve synergistic photothermal immunotherapy for prevention of breast cancer postoperative relapse. Self-assembled multifunctional nanoparticles (RIC NPs) are composed of three therapeutic components including indocyanine green, a photothermal agent; resiquimod (R848), a TLR-7/8 agonist; and CPG ODNs, a TLR-9 agonist. RIC NPs are physically incorporated into the thermosensitive PLEL hydrogel. The RIC NPs encapsulated PLEL hydrogel (RIC NPs@PLEL) is then locally injected into the tumor resection cavity for local photothermal therapy to ablate residue tumor tissues and produce tumor-associated antigens. At the same time, NIR also triggers the release of immune components CPG ODNs and R848 from thermoresponsive hydrogels PLEL. The released immune components, together with tumor-associated antigens, work as an in situ cancer vaccine for postsurgical immunotherapy by inducing effective and sustained antitumor immune effect. Overall, this work suggests that photothermal immunotherapy based on local hydrogel delivery system has great potential as a promising tool for the postsurgical management of breast cancer to prevent recurrences and metastases.
关键词： cancer recurrence,thermal-responsive hydrogels,immunotherapy,controlled drug release,photothermal
更新于2025-09-23 15:21:01
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Novel phthalocyanine-based micelles/PNIPAM composite hydrogels: spatial/temporal-controlled drug release triggered by NIR laser irradiation
摘要： Near-infrared (NIR) light-responsive hydrogels hold significant potential for biomedical application, especially in remote-controlled release of anticancer drugs. Herein we report a novel NIR light responsive composite hydrogel system that undergoes structural changes to realize drug delivery and precise release, which are constructed by poly (N-isopropylacrylamide) network and photothermal agent 4OCSPC/F127 micelles.
关键词： PNIPAM,NIR light-responsive hydrogels,4OCSPC/F127 micelles,drug delivery,photothermal agent
更新于2025-09-23 15:21:01
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Thermoplasmonica??Activated Hydrogel Based Dynamic Light Attenuator
摘要： This work describes the morphological, optical, and thermo-optical properties of a temperature-sensitive hydrogel poly(N-isopropylacrylamide-co-N-isopropylmethacrylamide) [P(NIPAm-co-NIPMAm]) film containing a specific amount of gold nanorods (GNRs). The light-induced thermoplasmonic heating of GNRs is used to control the optical scattering of an initially transparent hydrogel film. A hydrated P(NIPAm-co-NIPMAm) film is optically clear at room temperature. When heated to temperatures over 37 °C via light irradiation with a resonant source (λ = 810 nm) to the GNRs, a reversible phase transition from a swollen hydrated state to a shrunken dehydrated state occurs. This phenomenon causes a drastic and reversible change in the optical transparency from a clear to an opaque state. A significant red shift (≈30 nm) of the longitudinal band can also be seen due to an increased average refractive index surrounding the GNRs. This change is in agreement with an ad hoc theoretical model which uses a modified Gans theory for ellipsoidal nanoparticles. Morphological analysis of the composite film shows the presence of well-isolated and randomly dispersed GNRs. Thermo-optical experiments demonstrate an all-optically controlled light attenuator (65% contrast ratio) which can be easily integrated in several modern optical applications such as smart windows and light-responsive optical attenuators.
关键词： gold nanorods,active plasmonics,optical attenuators,polymers,optical transparency,hydrogels,plasmonic nanoparticles
更新于2025-09-23 15:19:57
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Engineering Quantum Dots with Ionic Liquid: A Multifunctional White Light Emitting Hydrogel for Enzyme Packaging
摘要： Herein, a new and straightforward approach for the fabrication of a stable and multifunctional white light emitting (WLE) hydrogel is reported. For the first time, the utility of such hydrogels for protein packaging with enhanced activity and stability is presented. Initially, a WLE composite with color chromaticity of (0.33, 0.27) is fabricated by engineering the surface of an orange light emitting Mn2+-doped ZnS quantum dot (QD) using a blue-emitting choline-tosylate ionic liquid (IL). The color chromaticity can be tuned by altering the concentration of the IL and excitation wavelengths. The WLE hydrogel is constructed through the conjugation of the WLE QD-IL composite with an alginate biopolymer. Remarkably, the WLE QD-IL composite and WLE hydrogel show preservation of their structural and luminescence properties for an extended time and thus indicate a potential for storage applications. When cytochrome c (Cyt C) is caged within the WLE hydrogel matrix, the peroxidase activity increases by more than 1.7-times compared with native Cyt C and a Cyt C-loaded QD hydrogel at room temperature. Also, Cyt C-immobilized WLE hydrogel shows a 3.5-fold increase in activity (compared with native Cyt C) at a higher temperature (120 °C) and in the presence of a denaturation agent.
关键词： ionic liquids,hydrogels,cytochrome C,white light emissions,quantum dots
更新于2025-09-23 15:19:57
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Long-Term Perfusion Culture of Monoclonal Embryonic Stem Cells in 3D Hydrogel Beads for Continuous Optical Analysis of Differentiation
摘要： Developmental cell biology requires technologies in which the fate of single cells is followed over extended time periods, to monitor and understand the processes of self-renewal, differentiation, and reprogramming. A workflow is presented, in which single cells are encapsulated into droplets (?: 80 μm, volume: ≈270 pL) and the droplet compartment is later converted to a hydrogel bead. After on-chip de-emulsification by electrocoalescence, these 3D scaffolds are subsequently arrayed on a chip for long-term perfusion culture to facilitate continuous cell imaging over 68 h. Here, the response of murine embryonic stem cells to different growth media, 2i and N2B27, is studied, showing that the exit from pluripotency can be monitored by fluorescence time-lapse microscopy, by immunostaining and by reverse-transcription and quantitative PCR (RT-qPCR). The defined 3D environment emulates the natural context of cell growth (e.g., in tissue) and enables the study of cell development in various matrices. The large scale of cell cultivation (in 2000 beads in parallel) may reveal infrequent events that remain undetected in lower throughput or ensemble studies. This platform will help to gain qualitative and quantitative mechanistic insight into the role of external factors on cell behavior.
关键词： microdroplets,hydrogels,single cell analysis,stem cells,pluripotency
更新于2025-09-23 15:19:57
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Optical properties of corals distort variable chlorophyll fluorescence measurements
摘要： Pulse amplitude modulated (PAM) fluorimetry is widely used in photobiological studies of corals, as it rapidly provides numerous photosynthetic parameters to assess coral ecophysiology. Coral optics studies have revealed the presence of light gradients in corals, which are strongly affected by light scattering in coral tissue and skeleton. We investigated whether coral optics affects variable chlorophyll fluorescence measurements and derived photosynthetic parameters by developing planar hydrogel slabs with immobilized microalgae and with bulk optical properties similar to those of different types of corals. Our results show that PAM-based measurements of photosynthetic parameters differed substantially between hydrogels with different degrees of light scattering but identical microalgal density, yielding deviations in apparent maximal electron transport rates by a factor of 2. Furthermore, system settings such as the measuring light intensity affected F0, Fm and Fv/Fm in hydrogels with identical light absorption but different degrees of light scattering. Likewise, differences in microalgal density affected variable chlorophyll fluorescence parameters, where higher algal densities led to greater Fv/Fm values and relative electron transport rates. These results have important implications for the use of variable chlorophyll fluorimetry in ecophysiological studies of coral stress and photosynthesis, as well as other optically dense systems such as plant tissue and biofilms.
关键词： light scattering,PAM fluorimetry,photosynthesis,hydrogels,variable chlorophyll fluorescence,coral optics
更新于2025-09-19 17:15:36
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Ocean Salinity Sensing Using Long-Period Fiber Gratings Functionalized with Layer-by-Layer Hydrogels
摘要： Rapid, accurate, and real-time measurements of ocean salinity are of great importance for a host of scientific, commercial, and defense applications. We demonstrate a highly sensitive, fast-responding fiber-optic salinity sensor that integrates long-period fiber gratings (LPFGs) with ionic strength-responsive hydrogel. The submicron-thick hydrogel was synthesized via layer-by-layer electrostatic assembly of partially quaternized poly(4-vinylpyridine) (qP4VP) and poly(acrylic acid), followed by chemical cross-linking. Spectroscopic ellipsometry measurement of a hydrogel made of 37% quaternized qP4VP showed robust and reversible swelling/deswelling in solutions with salt concentrations ranging from 0.4 to 0.8 M (22.8?44.7 g/kg) around pH 8.1. The swelling/deswelling process induced large changes in the refractive index of the hydrogel, leading to resultant shift in the resonance wavelength (RW) of LPFGs. The salinity-dependent optical response of the hydrogel-coated LPFGs is in good agreement with ellipsometry measurement. LPFGs coated with the hydrogel exhibited a sensitivity of 7 nm RW shift/M (125.5 pm/‰) with a measurement time less than 5 s. The shift in the resonance wavelength correlated linearly with salt concentration, making quantification of measured salinity straightforward.
关键词： refractive index,layer-by-layer assembly,hydrogels,ocean salinity sensing,long-period fiber gratings,ionic strength
更新于2025-09-19 17:15:36