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A simple layer-stacking technique to generate biomolecular and mechanical gradients in photocrosslinkable hydrogels
摘要： Physicochemical and biological gradients are desirable features for hydrogels to enhance their relevance to biological environments for three-dimensional (3D) cell culture. Therefore, simple and efficient techniques to generate chemical, physical and biological gradients within hydrogels are highly desirable. This work demonstrates a technique to generate biomolecular and mechanical gradients in photocrosslinkable hydrogels by stacking and crosslinking prehydrogel solution in a layer by layer manner. Partial crosslinking of the hydrogel allows mixing of prehydrogel solution with the previous hydrogel layer, which makes a smooth gradient profile, rather than discrete layers. This technique enables the generation of concentration gradients of bovine serum albumin in both gelatin methacryloyl (GelMA) and poly(ethylene glycol) diacrylate hydrogels, as well as mechanical gradients across a hydrogel containing varying gel concentrations. Fluorescence microscopy, mechanical testing, and scanning electron microscopy show that the gradient profiles can be controlled by changing both the volume and concentration of each layer as well as intensity of UV exposure. GelMA hydrogel gradients with different Young’s moduli were successfully used to culture human fibroblasts. The fibroblasts migrated along the gradient axis and showed different morphologies. In general, the proposed technique provides a rapid and simple approach to design and fabricate 3D hydrogel gradients for in vitro biological studies and potentially for in vivo tissue engineering applications.
关键词： 3D cell culture,Gelatin methacryloyl,Photocrosslinkable hydrogel,Poly(ethylene glycol) diacrylate,Gradient
更新于2025-11-21 11:24:58
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Visualizing Cell-Laden Fibrin-Based Hydrogels using Cryogenic Scanning Electron Microscopy and Confocal Microscopy
摘要： The present investigation explores the microscopic aspects of cell-laden hydrogels at high resolutions, using three-dimensional cell cultures in semi-synthetic constructs that are of very-high water content (>98% water). The study aims to provide an imaging strategy for these constructs, while minimizing artifacts. Constructs of PEG-fibrinogen (PEG-Fb) and fibrin hydrogels containing embedded mesenchymal cells (human dermal fibroblasts) were first imaged by confocal microscopy. Next, high resolution scanning electron microscopy (HR-SEM) was used to provide images of the cells within the hydrogels, at submicron resolutions. Because it was not possible to obtain artifact-free images of the hydrogels using room-temperature HR-SEM, a cryogenic HR-SEM (cryo-HR-SEM) imaging methodology was employed to visualize the sample while preserving the natural hydrated state of the hydrogel. The ultrastructural details of the constructs were observed at subcellular resolutions, revealing numerous cellular components, the biomaterial in its native configuration, and the uninterrupted cell membrane as it relates with the biomaterial in the hydrated state of the construct. Constructs containing microscopic albumin microbubbles were also imaged using these methodologies to reveal fine details of the interaction between the cells, the microbubbles and the hydrogel. Taken together with the confocal microscopy, this imaging strategy provides a more complete picture of the hydrated state of the hydrogel network with cells inside. As such, this methodology addresses some of the challenges of obtaining this information in amorphous hydrogel systems containing a very-high water content (>98%) with embedded cells. Such insight may lead to better hydrogel-based strategies for tissue engineering and regeneration.
关键词： Fibrin,Electron Microscopy,Hydrogel,Tissue Engineering,Scaffold,Confocal Microscopy
更新于2025-11-21 11:08:12
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A Near Infrared-Modulated Thermosensitive Hydrogel for Stabilization of Indocyanine Green and Combinatorial Anticancer Phototherapy
摘要： Indocyanine green (ICG), a multifunctional near-infrared (NIR) imaging agent approved by the FDA, has been extensively used in clinical cancer theranosis, but limited by its inherent instability, short plasma half-life and lack of targeting ability. Herein, an in situ formed photothermal network based thermosensitive hydrogel (PNT-gel) constructed by supramolecular cross-linking conjugated polymers was developed for stabilization of ICG and efficient combinatorial photothermal/photodynamic antitumor therapy. While the conjugated polymeric backbone in PNT-gel anchored the aromatic phototherapeutic agent ICG via π–π stacking interactions to avoid premature leakage, it also directly converted low-dose NIR light to induce localized hyperthermia to enhance the photothermal effect. The PNT-gel shows a reversible gel-to-sol upper critical solution temperature (UCST) that is slightly above the body temperature. Therefore, the controlled release of ICG was switched on or off by NIR via photothermal-induced gel-sol transition. In vitro and in vivo antitumor experiments demonstrated that ICG loaded PNT-gel not only efficiently induced the killing of 4T1 cancer cells, but also achieved almost complete eradication of 4T1 cells by one-dose in combinatorial photothermal/photodynamic therapy under irradiation of a low-dose 808 nm laser (0.14 W cm-2). Additionally, the combinational therapy proved to enhance the effectiveness of photodestruction without tumor recurrence compared with intratumoral injection photothermal therapy (PTT) or photodynamic therapy (PDT) treatment alone.
关键词： Near Infrared-Modulated Thermosensitive Hydrogel,Combinatorial Anticancer Phototherapy,Indocyanine Green,Photodynamic Therapy,Photothermal Therapy
更新于2025-11-21 11:08:12
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Cross-linking induced thermoresponsive hydrogel with light emitting and self-healing property
摘要： Development of self-healing hydrogels with thermoresponse is very important for artificial smart materials. In this article, the self-healing hydrogels with reversible thermoresponse were designed through cross-linking-induced thermoresponse (CIT) mechanism. The hydrogels were prepared from ketone group containing copolymer bearing tetraphenyl ethylene (TPE) and cross-linked by naphthalene containing acylhydrazide cross-linker. The mechanical property, light emission, self-healing, and thermo-response of the hydrogels were investigated intensively. With regulation of the copolymer composition, hydrogels showed thermoresponse with the LCST varied from above to below body temperature. At the same time, the hydrogels showed self-healing property based on the reversible characteristic of the acylhydrazone bond. The hydrogel also showed temperature-regulated light emission behavior based on AIE property of the TPE unit.
关键词： TPE,cross-linking-induced thermoresponse,hydrogel,self-healing,light emission
更新于2025-11-14 15:27:09
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Cross-linking induced thermo-responsive self-healable hydrogels with temperature regulated light emission property
摘要： Self-healing hydrogels draw great attentions in past decade based on the self-healing property similar to living creatures and their potential application in bioscience. On the other hand, thermo-response of the hydrogel endow the hydrogel with smart characteristic for controlled drug loading and delivery, diagnosis, cell imaging, life simulation, etc. In this study, self-healable hydrogel with cross-linking induced thermo-response (CIT) property was prepared from TPE containing copolymer TPE-P(DMA-stat-DAA) and the LCST of the hydrogels could be regulated by copolymer composition and the structure of the cross-linkers. The light emission property, mechanical and self-healing performances of the hydrogels are also investigated intensively. The results showed the LCST of the hydrogels could be regulated to body temperature through cross-linking induced thermo-response (CIT) mechanism with PEO23 DNH cross-linking. At the same time, the hydrogels exhibit light emission property, excellent self-healing ability and good mechanical properties. Moreover, the hydrogels showed different light emission property regulated by temperature based on AIE property of the TPE.
关键词： Light emission,Self-healing hydrogel,Cross-linking induced thermo-response
更新于2025-11-14 15:26:12
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Matrix Metalloproteinase-Deactivating Contact Lens for Corneal Melting
摘要： Corneal melting is an uncontrolled, excessive degradation of cellular and extracellular components of the cornea. This potential cause of corneal blindness is caused by excessive expression of zinc-dependent matrix metalloproteinases (MMPs) and has no satisfying cure as of now. Herein, we introduce a novel therapeutic hydrogel which can be made into a contact lens to slow down the progression of corneal melting by deactivating MMPs. The hydrogel backbone is comprised of poly(2-hydroxyetyl methacrylate) (pHEMA), a main material for commercial contact lenses, and dipicolylamine (DPA) which has high affinity and selectivity towards zinc ion. Due to the high affinity towards zinc ions, the DPA-conjugated pHEMA (pDPA-HEMA) hydrogel selectively removes zinc ions from a physiological buffer and deactivates MMP-1, MMP-2 and MMP-9 within 2 hours. pDPA-HEMA hydrogel also effectively prevents degradation of porcine corneas by collagenase A, a zinc-dependent protease, whereas the corneas completely degrades within 15 hours when incubated with pHEMA hydrogel. The presence of pDPA-HEMA hydrogel does not affect the viability of keratocytes and corneal epithelial cells. Unlike the conventional MMP inhibitors (MMPi), the pDPA-HEMA hydrogel minimizes the risk of serious non-specific side effects, and provides a method to slow down the progression of corneal melting and other related ocular diseases.
关键词： dipicolylamine,contact lens,corneal melting,hydrogel,zinc,matrix metalloproteinases
更新于2025-09-23 15:23:52
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Near infrared light-responsive heat-emitting hemoglobin hydrogels for photothermal cancer therapy
摘要： Photothermal therapy (PTT) is an effective means of treating tumors because tumor cells are sensitive to heat. Gold and carbon nanoparticles are used as efficient PTT materials. However, development of a non-toxic biodegradable PTT agent remains a challenge. Here, we developed a hemoglobin (Hb) hydrogel that exhibited excellent PTT effects in vitro and in vivo. Unlike conventional PTT agents, which are toxic and do not decompose completely in the body, the Hb hydrogel was manufactured using only two components: (i) Hb, a natural substance derived from the human body, and (ii) PEG, an FDA-approved polymer. The gelation time of the Hb hydrogels could be controlled by changing the Hb concentration. Because Hb is present at a high concentration (150 mg/ml) in the body, the Hb hydrogel decomposed and was eliminated in vivo without toxicity. The Hb hydrogel showed an excellent PTT effect in response to 808 nm near-infrared (NIR) laser irradiation and had excellent anticancer effects against A549 lung cancer cells both in vitro and in vivo. Blood hematology and blood biochemical assay results from an animal model treated with Hb hydrogel were similar to those of the control group. Importantly, toxicity was not observed based on H&E staining of major organs (heart, liver, spleen, kidneys and lung). Tumors of A549 cell-xenografted mice treated with Hb hydrogel and 808 nm NIR laser irradiation were significantly smaller than those of the control group (23.1 mm3 versus 746.5 mm3, respectively). This is a first report of a biocompatible photothermal hydrogel based on hemoglobin, and our overall results suggest that Hb hydrogels are commercially-promising PTT systems that have excellent anti-cancer effects.
关键词： Biocompatibility,Quick gelation,Lung cancer,Hemoglobin,Hydrogel,Photothermal therapy
更新于2025-09-23 15:23:52
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Light emitting self-healable hydrogel with bio-degradability prepared form pectin and Tetraphenylethylene bearing polymer
摘要： Self-healable hydrogel have wide applications in bioscience. In this research, self-healable hydrogel were prepared from TPE-[P(DMA-stat-DAA)]2 and acylhydrazide functionalized pectin. The TPE containing polymer endowed the hydrogel with light emission property while the pectin make the hydrogel biodegradable. Results showed that the pectin acylhydrazide can be prepared conveniently from pectin through hydrazinolysis. Light emissive hydrogels formed and self-healed without additional stimulus. More importantly, the hydrogel become light emitting with PL intensity higher than the polymer solution. The reason for this result is because the TPE units aggregated in the hydrophobic pectin ring and triggered AIE property. With biodegradable pectin, the hydrogel could be degraded naturally without worrying about the toxicity of the hydrogel in future bio-applications.
关键词： Self-healing,Hydrogel,TPE,Pectin,Light emission
更新于2025-09-23 15:23:52
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Prussian blue nanosphere-embedded in situ hydrogel for photothermal therapy by peritumoral administration
摘要： To establish an injectable hydrogel containing prussian blue (PB) nanospheres for photothermal therapy against cancer, PB nanospheres were prepared by one-pot synthesis and the thermosensitive Pluronic F127 was used as the hydrogel matrix. The PB nanospheres and the hydrogel were characterized by shape, particle size, serum stability, photothermal performance upon repeated 808 nm laser irradiation, as well as the rheological features. The effect of the PB nanospheres and the hydrogel were evaluated qualitatively and quantitatively in 4T1 mouse breast cancer cells. The retention, photothermal efficacy, therapeutic effects and systemic toxicity of the hydrogel were assessed in a tumor-bearing mouse model. The PB nanospheres had a diameter of about 150 nm and exhibited satisfactory serum stability, photo-heat convert ability and repeated laser exposure stability. The hydrogel encapsulation did not negatively influence the above features of the photothermal agent. The nanosphere-containing hydrogel showed a phase transition at body temperature and, as a result, a long retention time in vivo. The photothermal agent-embedded hydrogel displayed promising photothermal therapeutic effects in the tumor-bearing mouse model with little-to-no systemic toxicity after peritumoral administration.
关键词： PB,In situ,Thermosensitive,Hydrogel,Photothermal,Injectable,Nanospheres
更新于2025-09-23 15:23:52
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Morpholino Oligonucleotide Cross-Linked Hydrogels as Portable Optical Oligonucleotide Biosensors
摘要： Morpholino Oligonucleotides (MOs), an uncharged DNA analogue, are functionalized with an acrylamide moiety and incorporated into polymer hydrogels as responsive crosslinks for microRNA sequence detection. The MO crosslinks can be selectively cleaved by a short target analyte single-stranded DNA (ssDNA) sequence based on microRNA, inducing a distinct swelling response measured optically. The MO crosslinks offer significant improvement over DNA based systems through improved thermal stability, no salt requirement and 1000-fold improved sensitivity over a comparative biosensor, facilitating a wider range of sensing conditions. Analysis was also achieved using a mobile phone camera, demonstrating portability.
关键词： microRNA,Biosensor,Oligonucleotide sensor,Morpholino oligonucleotide,Hydrogel
更新于2025-09-23 15:23:52