Hydrogel Nanoparticles Research Articles

Development and Evaluation of the Acaricidal Activity of Xantan Gum-Based Hydrogel and Polymeric Nanoparticles Containing Achyrocline satureioides Extract.

The Rhipicephalus microplus tick causes enormous economic losses in livestock farming around the world. Despite several promising studies carried out with plant extracts such as Achyrocline satureioides against this ectoparasite, a major obstacle is related to pharmaceutical presentation forms. There is no study showing xantan gum-based hydrogel and polycaprolactone nanoparticles containing A. satureioides extract against R. microplus larvae. The objective of this study was to incorporate A. satureioides extract to develop a nanoformulation (AScn) and a hydrogel (ASlh) and evaluate them against R. microplus larvae with the purpose of increasing the contact time of the extract with the larvae and improve the effectiveness. The ethanolic extracts were incorporated in polycaprolactone nanoparticles and characterized via analysis of the mean hydrodinamic diameter and polidispersity index. The xanthan gum-based hydrogel formulation was prepared with crude extract of A. satureioides 40 mg/mL, 0.25% xanthan gum, and 8% poloxamer, to determine the bioadhesiveness of the formulation in bovine leather and the flow rate of the formulation in the animal. The results in larvae demonstrated that when evaluated in the form of a hydrogel (ASlh), mortality was higher, with 91.48% mortality at a concentration of 20 mg/mL presenting itself as an interesting alternative for controlling this ectoparasite.

Zinc-based Polyoxometalate Nanozyme Functionalized Hydrogels for optimizing the Hyperglycemic-Immune Microenvironment to Promote Diabetic Wound Regeneration.

In diabetic wounds, hyperglycemia-induced cytotoxicity and impaired immune microenvironment plasticity directly hinder the wound healing process. Regulation of the hyperglycemic microenvironment and remodeling of the immune microenvironment are crucial. Here, we developed a nanozymatic functionalized regenerative microenvironmental regulator (AHAMA/CS-GOx@Zn-POM) for the effective repair of diabetic wounds. This novel construct integrated an aldehyde and methacrylic anhydride-modified hyaluronic acid hydrogel (AHAMA) and chitosan nanoparticles (CS NPs) encapsulating zinc-based polymetallic oxonate nanozyme (Zn-POM) and glucose oxidase (GOx), facilitating a sustained release of release of both enzymes. The GOx catalyzed glucose to gluconic acid and (H₂O₂), thereby alleviating the effects of the hyperglycemic microenvironment on wound healing. Zn-POM exhibited catalase and superoxide dismutase activities to scavenge reactive oxygen species and H₂O₂, a by-product of glucose degradation. Additionally, Zn-POM induced M1 macrophage reprogramming to the M2 phenotype by inhibiting the MAPK/IL-17 signaling diminishing pro-inflammatory cytokines, and upregulating the expression of anti-inflammatory mediators, thus remodeling the immune microenvironment and enhancing angiogenesis and collagen regeneration within wounds. In a rat diabetic wound model, the application of AHAMA/CS-GOx@Zn-POM enhanced neovascularization and collagen deposition, accelerating the wound healing process. Therefore, the regenerative microenvironment regulator AHAMA/CS-GOx@Zn-POM can achieve the effective conversion of a pathological microenvironment to regenerative microenvironment through integrated control of the hyperglycemic-immune microenvironment, offering a novel strategy for the treatment of diabetic wounds.

Synthesis of Multivalent Glycoside-Immobilized Carboxymethyl Cellulose Nanohydrogel Particles with Superadsorption Ability for Lectins.

Carboxymethyl cellulose (CMC) is a water-soluble cellulose derivative that is nontoxic, biocompatible, biodegradable, and nonallergenic. As developing an adsorbent material for carbohydrate-binding proteins is challenging, we aimed to synthesize CMC nanohydrogel particles (CMCGPs) with an extremely high lectin adsorption tendency in this study. CMCGPs were used as the backbone of an adsorption carrier that was synthesized by cross-linking CMC with ethylene glycol diglycidyl ether. A series of glycoside-immobilized CMCGPs were synthesized by binding two types of glycans (LacNAc and lactose) to the polyvalent carboxymethyl groups that are present on the CMCGP surface and act as reaction sites. These immobilized glycosides function as molecular recognition sites. Glycan moieties were incorporated into the CMCGP backbone at degrees of immobilization (DI) ranging from 8.7 to 21.0% by altering the reaction composition. LacNAc-CMCGP (3b) showed a 19.9% DI of LacNAc glycoside to the CMCGP carboxymethyl group; on average, its particle size swelled to 418 nm in phosphate-buffered saline, which is approximately 1.4 times its dry-state size. Analyzing the adsorbent properties of glyco-CMCGPs using a lectin-binding assay showed the high structural specificity of glyco-CMCGPs to lectins. The equilibrium isotherm data was explained by the Langmuir adsorption model. Notably, compound 3b adsorbed 1.95 ± 0.05 μg of wheat germ agglutinin (WGA) lectin per 1.0 μg-dry of 3b particles at an adsorption equilibrium time of a few minutes. Furthermore, solid-state 13C nuclear magnetic resonance analysis showed that WGA lectin retained its natural structure without denaturation after binding to LacNAc-CMCGP. These results were also supported by affinity purification experiments of WGA from raw wheat germ extract using LacNAc-CMCGP, demonstrating that glyco-CMCGP is capable of adsorbing and desorbing lectin while maintaining its biological activity. Thus, multivalent glycoside-immobilized CMCGPs that use woody biomass derivatives as the backbone are expected to be applied as biorefinery materials, which specifically and abundantly adsorb not just plant lectins but also pathogenic viruses and toxin proteins.

Environmentally Friendly Synthesis of Gelatin Hydrogel Nanoparticles for Gastric Cancer Treatment, Bisphenol A Sensing and Nursing Applications: Fabrication, Characterization and ANN Modeling

This study presents a dual application approach for the environmentally friendly synthesis of gelatin hydrogel nanoparticles with potential applications in gastric cancer treatment, bisphenol A (BPA) sensing, and nursing. Gelatin hydrogel nanoparticles were synthesized using a green and freeze-drying method, avoiding the use of toxic chemicals and solvents. The nanoparticles showed excellent biocompatibility and promising potential for drug delivery system (DDS) in gastric cancer treatment. The controlled release of anticancer drugs from the gelatin nanoparticles was showed, highlighting their potential in targeted therapy. Additionally, the gelatin hydrogel nanoparticles were explored for BPA sensing. BPA is a widely used chemical known for its adverse effects on human health. The gelatin nanoparticles showed high selectivity and sensitivity towards BPA detection, making them suitable for environmental monitoring and health applications using scanning electron microscope (SEM). Also, in this study, an artificial neural network (ANN) was used to estimate the release of docetaxel (%) at 72 hours, the release of paclitaxel (%) at 72 hours, tensile strength with sample (wt%), and porosity (%) in broader ranges than the experimental samples. The environmentally friendly synthesis of gelatin hydrogel nanoparticles presented in this study offers a versatile platform with dual applications in gastric cancer treatment and sensing of harmful chemicals. The obtained results show the potential of these nanoparticles for innovative therapeutic and diagnostic strategies in healthcare and environmental monitoring. The study showed the development of sustainable and multifunctional nanomaterials for various biomedical applications. The modeling of the neural network predictions shows that increasing the sample (wt%) and porosity (%) leads to an increase in the release of docetaxel (%) at 72 hours, the release of paclitaxel (%) at 72 hours, and tensile strength. As porosity decreases, the release of docetaxel increases, and the release of paclitaxel and tensile strength also increase. Additionally, the prediction errors of the ANN in this study were evaluated using linear regression, showing acceptable error rates compared to the target results obtained from the experimental tests.

Locally Injectable Chitosan/β-Glycerophosphate Hydrogel Doped with Triptolide-Human Serum Albumin Nanoparticles for Treating Rheumatoid Arthritis.

Rheumatoid arthritis (RA) tends to occur in symmetrical joints and is always accompanied by synovial hyperplasia and cartilage damage. Triptolide (TP), an extract from Tripterygium, has anti-inflammatory and immunomodulatory properties and could be used in the treatment of RA. However, its poor water solubility and the multi-system lesions caused by the use of this substance limit its clinical application. Therefore, it would be of great significance to assemble a composite nanoparticle hydrogel and apply it to a collagen-induced arthritis (CIA) mouse model to investigate the therapeutic effect and biosafety of this compound. TP@HSA nanoparticles (TP@HSA NPs) were fabricated with a self-assembly method; a thermosensitive hydrogel loaded with the TP@HSA NPs (TP@HSA NP hydrogel) was prepared by using chitosan and beta- glycerophosphate (β-GP) and was then intra-articularly injected into CIA mice. The changes in joint swelling were measured with a digital caliper, and inflammation and cartilage damage were evaluated by using hematoxylin and eosin (H&E) and safranin O-fast green (SO&FG) staining, respectively. TP@HSA NPs with an average diameter of 112 ± 2 nm were successfully assembled, and their encapsulation efficiency and drug loading efficiency were 47.6 ± 1.5% and 10.6 ± 3.3%, respectively. The TP@HSA NP hydrogel had a gelation temperature of 30.5 ± 0.2 °C, which allows for its injection at low temperatures and its sol-gel transformation under physiological conditions within 2 min, making it a suitable drug depot. The TP@HSA NP hydrogel was intra-articularly injected into CIA mice; it released TP locally and exerted anti-inflammatory and immunomodulatory effects, alleviating synovial inflammation and cartilage damage effectively. We successfully fabricated a TP@HSA NP-loaded thermosensitive hydrogel with good biosafety, which can release TP slowly for the treatment of RA. Our study provides a basis for the development of TP-based innovative preparations and has good application prospects.

Bufalin CaCO3 Nanoparticles Triggered Pyroptosis through Calcium Overload via Na+/Ca2+ Exchanger Reverse for Cancer Immunotherapy.

Bufalin is a promising active ingredient in traditional Chinese medicine but has shown limited anticancer applications due to its toxicity. Here, we report BCNPs@gel, a bufalin-containing CaCO3 nanoparticle hydrogel, for enhancing cancer treatment through inducing cellular pyroptosis. Under the tumor microenvironment's low pH conditions, bufalin and Ca2+ are released from the delivery system. Bufalin serves as a direct anticancer drug and a Na+/K+-ATPase inhibitor by forcing the Na+/Ca2+ exchanger to reverse its function, which transfers Ca2+ into cytoplasm and ultimately causes Ca2+ overload-triggered pyroptosis. Meanwhile, we found that bufalin can upregulate PD-L1 in tumor cells. In combination with the PD-1 antibody, the delivery system showed a greater performance during the cancer treatment. BCNPs@gel enhances antitumor efficiency, reduces systemic side effects, extends antitumor mechanism of bufalin, and provides new strategies for inducing pyroptosis and calcium overload in cancer immunotherapy via Na+/K+-ATPase inhibitor. This work provides an application model for numerous other traditional Chinese medicine ingredients.

Integrating synthetic hydrogel nanoparticles with carbon dots for selective detection of hemoglobin

Synthetic hydrogel nanoparticles (NPs) display high affinity to biomacromolecules target and have significant potential as protein capture agents for medical and biotechnological applications. In this study, we proposed a strategy to modify Carbon dots (CDs) with engineered NPs to address their detection specificity in complex biological sensing matrices. A library of NPs tagged CDs (NPs@CDs) incorporating hydrophobic and carboxylate groups that bound with high affinity to hemoglobin (Hb) was prepared by precipitation polymerization and screened based on the fluorescence quenching effect. NPs and CDs were integrated through noncovalent interaction, which was confirmed by Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Dynamic Light Scattering (DLS) and Fourier transform infrared spectroscopy analyses. The specificity of NPs@CDs was prominently attributed to the unique affinity between the screened NPs and Hb, compared with the contrast fluorescence quenching study by corresponding CDs to structural analogues and coexistence substances of Hb. Moreover, the Hb-induced fluorescence quenching process was dominated by a synergistic effect of internal filter effect (IFE) and static quenching proved by UV–vis absorption spectrometry and time-resolved fluorescence spectrometry. The screened NPs@CDs showed strong recognition capability to Hb, and the fluorescence quenching rate was about 97 % which was 3.2 times that of CDs. A biosensing platform based on NPs@CDs was constructed, and the fluorescence signal of the nanoprobe decreased linearly as the concentration of Hb over the range of 0.2–80 μM L−1 with a detection limit of 7.5 nM L−1. The synergy between CDs and NPs resulted in high-speed real-time detection capability, high sensitivity, considerable specificity, low interference and good stability of this nanoprobe.

Versatile and Tunable Performance of PVA/PAM Tridimensional Hydrogel Models for Tissues and Organs: Augmenting Realism in Advanced Surgical Training.

The increasing complexity and difficulty of surgical procedures have led to a rise in medical errors within clinical settings in recent years. Gastrointestinal diseases, in particular, present significant medical challenges and impose substantial economic burdens, underscoring the urgent need for experiential, high-fidelity gastrointestinal surgical training tools. This study leverages patient-specific computed tomography (CT) and magnetic resonance imaging (MRI) data, combined with 3D printed manufacturing, to develop hydrogel organ models with tunable performance and tissue-mimicking softness. These properties are achieved by regulating the freeze-thaw cycles, cross-linking agents, and the concentration of incorporated antibacterial nanoparticles in DN hydrogels. Through the application of indirect 3D printing and the "sacrificial material method", we successfully fabricate organ tissues such as the stomach, intestines, and blood vessels with high precision. In ex vivo surgical training demonstrations, these tissue-like soft hydrogels provide an effective platform for preoperative simulation and surgical training in digestive surgery, accommodating various surgical procedures and accurately simulating intraoperative bleeding. The development of advanced bionic organ models with specific and tunable characteristics based on DN hydrogels is poised to significantly advance surgical training, medical device testing, and the reform of medical education.

Influence of Hydrogel and Zinc Oxide Nanoparticles on the Germination and Establishment of Chenopodium quinoa.

The aim of this study was to assess the influence of hydrogel and zinc oxide nanoparticles on quinoa germination and establishment. Various doses of a commercial potassium-based hydrogel (0, 5, 7, and 9 g), each dissolved in one liter of rainwater, were applied. Additionally, 1.5 g of zinc oxide nanoparticles (ZnO-NP) and pre-crushed nitrogen fertilizer, at a rate of 1.6 kg/ha, were added to the solution to achieve a homogeneous mixture. Following the application of hydrogel in the 10-linear-meter rows corresponding to each treatment area in every block, 25 seeds per linear meter of the "Blanca de Juli" quinoa cultivar were sown with a 4 cm spacing between the seeds. Subsequently, a thin layer of soil, approximately 0.5 cm thick, was used to cover the seeds. Ten seedlings were randomly selected and labeled for subsequent evaluations. The experimental design employed in this research was a completely randomized block design. The collected data underwent an analysis of variance, and the means of all the treatments were compared using Tukey's test with a 5% probability. Height and diameter evaluations of the plant neck were conducted every 45 days. The doses used in this study (5, 7, and 9 g of hydrogel per liter of water) significantly enhanced seed germination and increased the number of plants per linear meter (from 82.00 to 90.33) compared to the control dose without hydrogel (14.66), which resulted in an average of one plant per linear meter.

Exploring Hydrogel Nanoparticle Systems for Enhanced Ocular Drug Delivery.

Drug delivery to the ocular system is affected by anatomical factors like the corneal epithelium, blinking reflex, aqueous blood barrier, and retinal blood barrier, which lead to quick removal from the site and inefficient drug delivery. Developing a drug delivery mechanism that targets specific eye tissue is a major hurdle for researchers. Our study examines the challenges of drug absorption in these pathways. Hydrogels have been researched as a suitable delivery method to overcome some obstacles. These are developed alone or in conjunction with other technologies, such as nanoparticles. Many polymer hydrogel nanoparticle systems utilizing both natural and synthetic polymers have been created and investigated; each has pros and cons. The complex release mechanism of encapsulated agents from hydrogel nanoparticles depends on three key factors: hydrogel matrix swelling, drug-matrix chemical interactions, and drug diffusion. This mechanism exists regardless of the type of polymer. This study provides an overview of the classification of hydrogels, release mechanisms, and the role of controlled release systems in pharmaceutical applications. Additionally, it highlights the integration of nanotechnology in ocular disease therapy, focusing on different types of nanoparticles, including nanosuspensions, nanoemulsions, and pharmaceutical nanoparticles. Finally, the review discusses current commercial formulations for ocular drug delivery and recent advancements in non-invasive techniques. The objective is to present a comprehensive overview of the possibilities for enhancing ocular medication delivery through hydrogel nanoparticle systems.

Near-Infrared Stimuli-Responsive Hydrogel Promotes Cell Migration for Accelerated Diabetic Wound Healing.

Diabetic wound healing including diabetic foot ulcers is a major clinical challenge, which could bring an increased level of mortality and morbidity. However, conventional wound dressings exhibit limited healing efficacy due to their lack of active modulation for the healing process. Here, a near-infrared (NIR) stimuli-responsive composite hydrogel dressing with the synergistic effect of both mechanical contraction and epithelial-mesenchymal transition (EMT) was developed to facilitate cell migration and vascularization for diabetic wound healing. In the methacrylated gelatin-based composite hydrogel, N-isopropylacrylamide and polydopamine nanoparticles were incorporated to endow the composite hydrogel with thermosensitive and photothermal properties. Linagliptin (LIN) was loaded into the composite hydrogel, and the drug release rate could be controlled by NIR laser irradiation. NIR-triggered on-demand active contraction of wound area and LIN release for biological stimulation were potentially realized in this responsive system due to the thermally induced sol-gel transition of the composite hydrogel. The release of loaded LIN could effectively promote cell migration by activating EMT and enhancing angiogenesis. In the full-thickness skin defect model, the LIN-loaded composite hydrogel with NIR laser irradiation had the highest wound closure rate as compared with the pure hydrogel and LIN-loaded hydrogel groups. Therefore, this composite hydrogel can serve as an excellent platform for promoting wound healing and will find more practical value in clinical treatment.

PH-responsive mupirocin-loaded hybrid nanoparticles in hydrogel and film forming spray against resistant bacterial wound infections

The aim of this work was to fabricate smart Mupirocin loaded Lipid Polymeric Hybrid Nanoparticles (MUP-LPHNs) based hydrogel and Film forming spray (FFS) for targeted release of MUP in response to wound pH. The MUP-LPHNs were optimized through design expert v.12. The optimized MUP-LPHNs had a particle size of 270.7 ± 3.20 nm with zeta potential of 17.05 ± 1.20 mV and entrapment efficiency of 88.0 ± 0.35 %. MUP-LPHNs showed no major chemical interaction, spherical morphology and amorphous nature as confirmed by FTIR, SEM and XRD, respectively. MUP-LPHNs were loaded to MUP-LPHNs based hydrogel (MUP-LPHNs-HG) and MUP-LPHNs based film forming spray (MUP-LPHNs-FFS) with successful characterization. In vitro release data confirmed sustained and pH dependent release from both MUP-LPHNs-HG and MUP-LPHNs-FFS as higher release was observed at pH 7.4. MUP-LPHNs-HG and MUP-LPHNs-FFS showed high efficiency and long-term inhibition of Staphylococcus aureus (SA), Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) with 4–6 fold increase in the antibacterial activity compared to MUP solution. MUP-LPHNs-HG and MUP-LPHNs-FFS exhibited both in vitro and in vivo wound pH contingent, sustained drug release. Moreover, the prepared nanocarriers systems flaunted significant therapeutic efficacy against MRSA infected wound model by significant reduction in bacterial load and wound area, increased hydroxy proline level and antioxidant enzymes and reduced proinflammatory cytokines. Similarly, immunohistochemistry, histopathological and trichrome assessment showed significant reduction in level of inflammatory markers, accelerated and enhanced re-epithelization, improved connective tissue remodeling and effectively promote collagen deposition with effective wound regeneration, respectively. It can be concluded that LPHNs could be a potential carrier system for enhancing the therapeutic efficacy of MUP against resistant bacterial wound infections.

Femtosecond laser writing of ant-inspired reconfigurable microbot collectives

Microbot collectives can cooperate to accomplish complex tasks that are difficult for a single individual. However, various force-induced microbot collectives maintained by weak magnetic, light, and electric fields still face challenges such as unstable connections, the need for a continuous external stimuli source, and imprecise individual control. Here, we construct magnetic and light-driven ant microbot collectives capable of reconfiguring multiple assembled architectures with robustness. This methodology utilizes a flexible two-photon polymerization strategy to fabricate microbots consisting of magnetic photoresist, hydrogel, and metal nanoparticles. Under the cooperation of magnetic and light fields, the microbots can reversibly and selectively assemble (e.g., 90° assembly and 180° assembly) into various morphologies. Moreover, we demonstrate the ability of assembled microbots to cross a one-body-length gap and their adaptive capability to move through a constriction and transport microcargo. Our strategy will broaden the abilities of clustered microbots, including gap traversal, micro-object manipulation, and drug delivery.

Analysis of Structural Changes of pH-Thermo-Responsive Nanoparticles in Polymeric Hydrogels.

The pH- and thermo-responsive behavior of polymeric hydrogels MC-co-MA have been studied in detail using dynamic light scattering DLS, scanning electron microscopy SEM, nuclear magnetic resonance (1H NMR) and rheology to evaluate the conformational changes, swelling-shrinkage, stability, the ability to flow and the diffusion process of nanoparticles at several temperatures. Furthermore, polymeric systems functionalized with acrylic acid MC and acrylamide MA were subjected to a titration process with a calcium chloride CaCl2 solution to analyze its effect on the average particle diameter Dz, polymer structure and the intra- and intermolecular interactions in order to provide a responsive polymer network that can be used as a possible nanocarrier for drug delivery with several benefits. The results confirmed that the structural changes in the sensitive hydrogels are highly dependent on the corresponding critical solution temperature CST of the carboxylic (-COOH) and amide (-CONH2) functional groups and the influence of calcium ions Ca2+ on the formation or breaking of hydrogen bonds, as well as the decrease in electrostatic repulsions generated between the polymer chains contributing to a particle agglomeration phenomenon. The temperature leads to a re-arrangement of the polymer chains, affecting the viscoelastic properties of the hydrogels. In addition, the diffusion coefficients D of nanoparticles were evaluated, showing a closeness among with the morphology, shape, size and temperature, resulting in slower diffusions for larger particles size and, conversely, the diffusion in the medium increasing as the polymer size is reduced. Therefore, the hydrogels exhibited a remarkable response to pH and temperature variations in the environment. During this research, the functionality and behavior of the polymeric nanoparticles were observed under different analysis conditions, which revealed notable structural changes and further demonstrated the nanoparticles promising high potential for drug delivery applications. Hence, these results have sparked significant interest in various scientific, industrial and technological fields.

DNA Aptamer Integrated Hydrogel Nanocomposites on Screen Printed Gold Electrodes for Point-of-Care Detection of Testosterone in Human Serum.

This work describes the development and evaluation of a novel electrochemical aptasensor for testosterone detection. The sensor utilizes a specifically designed DNA immobilized on a screen-printed gold electrode (SPGE) modified with a conductive hydrogel and gold nanoparticles (HG/NP) composite. The aptasensor exhibited a dose-dependent response to testosterone (0.05 to 50 ng/mL) with a detection limit of 0.14 ng/mL and a good sensitivity of 0.23 μA ng-1 mL cm-2. The sensor displayed excellent selectivity towards testosterone compared to structurally similar steroid hormones. Importantly, the incorporation of HG/NP not only improved the sensor's conductivity but also acted as an antifouling layer, minimizing signal interference from non-specific biomolecule interactions in complex biological samples like human serum. The results obtained from the aptasensor showed good correlation with a standard ELISA method, demonstrating its effectiveness in real-world scenarios.

Injectable natural hydrogel with spatiotemporal self-strengthening, antibacterial and anti-inflammatory properties for treating diabetic wound

Injectable hydrogel dressings provide a promising approach for treating diabetic wounds as they conform to irregular surfaces and foster new tissue development in a moist environment. Nevertheless, post-injection mechanical performance is often mediocre, coupled with inadequate antibacterial protection. Herein, we prepared an injectable hydrogel dressing (CBGT@PDA) consisting of double-network hydrogel (CBGT) and polydopamine nanoparticles (PDA NPs) as a multi-targeted combination therapy system oriented to chronic diabetic wound healing. Efficient enzymatic reactions combined with a slow quaternization procedure regulate the mechanical attributes of injectable hydrogels, offering spatiotemporal self-strengthening and exceptional antibacterial capabilities. The hydrogel system is also equipped with scavenged ROS function, bioadhesion characteristics and remarkable biocompatibility, thus exhibiting high improvement in the healing of the diabetic wound. We believe such injectable hydrogels with spatiotemporal self-strengthening capabilities in both of mechanical and antibacterial properties will provide new insight into the hydrogel-based wound dressing and broaden the application of the bioinspired hydrogels in biomedical fields.

Mg-Sr-Ca containing bioactive glass nanoparticles hydrogel modified mineralized collagen scaffold for bone repair.

The aim of this study is to explore the therapeutic effects of Mg-Sr-Ca containing bioactive glass nanoparticles sodium alginate hydrogel modified mineralized collagen scaffold (Mg-Sr-Ca-BGNs-SA-MC) on the repair of osteoporotic bone defect. During the study, Mg-Sr-Ca containing bioactive glass nanoparticles (Mg-Sr-Ca-BGNs) were synthesized using the sol-gel method, and the Mg-Sr-Ca-BGNs-SA-MC scaffold was synthesized by a simple method. The Mg-Sr-Ca-BGNs and the Mg-Sr-Ca-BGNs-SA-MC scaffold were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elements of Mg, Sr, Ca and Si were effectively integrated into Mg-Sr-Ca-BGNs. SEM analysis revealed the presence of Mg-Sr-Ca-BGNs on the scaffold's surface. Furthermore, the cytotoxicity of the scaffolds were assessed using a live/dead assay. The result of the live/dead assay demonstrated that the scaffold materials were non-toxic to cell growth. More importantly, the in vivo study indicated that implanted scaffold promoted tissue regeneration and integration with newly formed bone. Overall, the Mg-Sr-Ca-BGNs-SA-MC scaffold is suitable for guided bone regeneration and beneficial to repair of osteoporotic bone defects.

Diffusion of nanoparticles in heterogeneous hydrogels as vitreous humour in vitro substitutes

Nanomedicine has the potential to increase the biostability of drugs to treat retinal diseases, improving their performance and decreasing the required number of intravitreal injections. However, accurate pharmacokinetic studies of these nanoparticle-drug conjugates, nanoparticle motion across the vitreous humour and interaction with the retinal cell layers still need to be investigated. Existing nanoparticle tracking techniques require fluorescent labels, which can impact cytotoxicity, nanoparticles’ motion, protein interactions, and cell internalization. In this study, a real-time label-free tracking technology, for single nanoparticles in an optical microscope based on the optical phenomena of caustics, was used to characterise the diffusion of nanoparticles in agar-hyaluronic acid hydrogels, previously validated as vitreous humour substitutes for in vitro models. The results demonstrated that the diffusion of nanoparticles through these hydrogels was heterogeneous, and that nanoparticle size had an important role in nanoparticle distribution across and within in vitro vitreous substitutes. These findings suggest that nanoparticle diameter is a critical parameter for designing novel therapeutics for retinal diseases. Moreover, nanoparticle charge did not affect nanoparticle diffusion or distribution in these synthetic hydrogels. The use of caustics in optical microscopy has been demonstrated to be a reproducible, inexpensive technique for screening novel therapeutics in eye in vitro models.

PH-Triggered Hydrogel Nanoparticles for Efficient Anticancer Drug Delivery and Bioimaging Applications.

In this work, we developed multifunctional hydrogel nanoparticles (NPs) that can encapsulate anticancer drugs and imaging contrast agents as well. Mitomycin C (MMC) and rhodamine B (RB) were selected as models for anticancer drugs and imaging contrasting agents, respectively. Both MMC and RB were linked to the succinated polyvinyl alcohol polymer (PVA-SA). The selected labeled hydrogel NPs ((0.5% RB)-PVA-SA NPs and (1.5% RB)-PVA-SA NPs) improved the RB quantum yield from 29.8% to a minimum of 42.7%. Moreover, they showed higher emission stability compared to free RB when they were repeatedly excited at 554 nm for 2 h. Furthermore, the dye polymeric interactions significantly increased the RB fluorescence lifetime by approximately twofold. All these optical properties pave the way for our labeled hydrogel NPs to be used in imaging-guided therapy. For the labeled MMC-loaded NPs, the MMC-binding efficiency was found to be exceedingly high in all synthesized samples: a minimum of 92% was achieved. In addition, the obtained pH-dependent drug release profiles as well as the cytotoxicity evaluation demonstrated the high potential of releasing MMC under acidic cancerous conditions. Moreover, the in vitro cellular uptake experiment confirmed the accumulation of MMC NPs throughout the cytoplasm.

Exploring the antimicrobial and antioxidant potential of bacterial cellulose-cerium oxide nanoparticles hydrogel: Design, characterization and biomedical properties

Bacterial cellulose (BC) is a promising natural polymer prized for its biocompatibility, microporosity, transparency, conformability, elasticity, and ability to maintain a moist wound environment while absorbing exudates. These attributes make BC an attractive material in biomedical applications, particularly in skin tissue repair. However, its lack of inherent antimicrobial activity limits its effectiveness. In this study, BC was enhanced by incorporating cerium (IV)-oxide (CeO2) nanoparticles, resulting in a series of bacterial cellulose-CeO2 (BC-CeO2) composite materials. Characterization via FESEM, XRD, and FTIR confirmed the successful synthesis of the composites. Notably, BC-CeO2-1 exhibited no cytotoxic or genotoxic effects on peripheral blood lymphocytes, and it additionally protected cells from genotoxic and cytotoxic effects in H2O2-treated cultures. Redox parameters in blood plasma samples displayed concentration and time-dependent trends in PAB and LPP assays. The incorporation of CeO2 nanoparticles also bolstered antimicrobial activity, expanding the potential biomedical applications of these composites.