Nanogels: Synthesis, properties, and recent biomedical applications

Recent advances in degraders engaging lysosomal pathways and related nanomedicine

The advent of targeted protein degradation (TPD) strategies presents unparalleled opportunities for innovating and expediting the development of new drugs. As the most mature TPD technology to date, proteolysis targeting chimeras (PROTACs) reliant on the ubiquitin proteasome system (UPS) have successfully transitioned from the laboratory to phase III clinical trials after nearly two decades of development. In recent years, the gradually emerging degraders engaging lysosomal pathways have further broadened the range of degradation mechanisms and substantially increased the diversity of potential targets and indications, ushering in a new era for the TPD field. Despite their significant advantages, the limited permeability, adverse pharmacokinetic properties, and off-target side effects caused by non-specific distribution still pose significant challenges to the clinical translation of these degraders. Currently, researchers are exploring the use of nanotechnology to surmount these obstacles and have achieved notable progress. This paper systematically summarizes the fundamental design principles, research status, challenges and future prospects of degraders engaging lysosomal pathways, and highlights the efforts and latest advances in related nanomedicine to optimize these degraders. The aim of this review is to deepen our comprehension of this emerging field and offer guidance for future exploration, development, and further utilization of new TPD techniques.

Trehalose-releasing nanogels reduce α-synuclein-induced Lewy body-like inclusions in primary mouse hippocampal neurons

Parkinson's disease (PD) is the second most prevalent age-related neurodegenerative disorder, clinically characterized by both motor and non-motor symptoms. A key hallmark of PD is the accumulation of misfolded α-synuclein, which aggregates to Lewy bodies (LB) formed inside neurons. Trehalose, a disaccharide that induces autophagy, has been demonstrated to reduce α-synuclein aggregation in vivo. However, the enzyme trehalase rapidly degrades free trehalose, and its hydrophilicity causes poor penetration through the cell membrane. Thus, advanced trehalose delivery strategies are urgently needed. Herein, we investigated the effects of trehalose-bearing nanogels for reducing α-synuclein protein-induced perinuclear LB-like pathology in primary mouse hippocampal neurons. The study compares the effects of trehalose-releasing nanogel (TR) and trehalose-non releasing nanogel (TNR). The results showed that TR, but not TNR, nor free trehalose reduced LB-like inclusions in primary hippocampal neurons. The neuroprotective effects of TR may result from the synergistic effects of direct limitation of α-synuclein aggregates formation and trehalose release-induced autophagy promoting aggregates clearance. Overall, enhancing trehalose delivery with nanogels that can sustainably release trehalose could be worth further investigation as a new potential option for reducing α-synuclein aggregation in neurons affected by neurodegenerative diseases.

Tumor-targeting and redox-responsive photo-cross-linked nanogel derived from multifunctional hyaluronic acid-lipoic acid conjugates for enhanced in vivo protein delivery

The fabrication of a secure and efficacious nanosystem for intracellular protein delivery is greatly desired, which relies on coordination of the interactions among loading ability, systemic stability, precise tumor targeting, successful endo-lysosomal evasion, and on-demand release characteristics. Herein, we constructed tumor-targeting and redox-responsive photo-crosslinkable nanogels (TRNGs) via UV light-induced ring-opening polymerization (ROP) of lipoic acid moieties incorporated in the side chain of methoxy poly (ethylene glycol) and diethylenetriamine-modified hyaluronic acid (HA-g-mPEG/Deta-c-LA) to create disulfide cross-linked core for the in vivo delivery of cytochrome c (CC). The TRNGs had satisfactory stability for 48 h in physiological environments and high CC encapsulation efficiency via multi-physical interactions. In vivo and in vitro fluorescence imaging proved the preferential accumulation of CC-loaded TRNGs in tumor tissues of human lung tumor-bearing mice and these nanoparticles were efficiently taken up into the CD44-positive A549 cells through CD44-mediated endocytosis compared to CD44-negative HepG2 cells. In addition, the nanoparticles underwent swift exocytosis from the endo-lysosomal compartment, thus promoting the liberation of CC within a reducing intracellular environment. The in vitro therapeutic outcomes proved that empty TRNGs presented excellent biocompatibility and minimal cytotoxicity, whereas CC-loaded TRNGs demonstrated a superior capacity to kill A549 cells compared to free CC and exhibited low effect on CD44-negative HepG2 cells. Moreover, CC-loaded TRNGs also had enhanced antitumor activity without eliciting any adverse effects. Our study highlighted the potential of TRNGs as a novel nanoplatform for the treatment of protein-based cancers.

Development of a Multi-Stimuli-Responsive Magnetic Nanogel-Hydrogel Nanocomposite for Prolonged and Controlled Doxorubicin Release

The development of advanced drug delivery systems that offer precise, controlled, and sustained release of therapeutic agents remains a significant challenge, particularly for applications in oncology where effective targeting and prolonged drug exposure are essential. We synthesized and characterized a multistimuli-responsive magnetic nanogel-hydrogel nanocomposite (MNHNC) designed for controlled and extended drug release, with an emphasis on anticancer drug delivery. The MNHNC was developed by incorporating poly(N-isopropylacrylamide-co-acrylamide) (p(NIPAM-co-AAm)) nanogels (NGs) within a net-shaped salep-grafted poly(acrylic acid) (PAA) hydrogel matrix, coupled with in situ formation of Fe3O4 nanoparticles to introduce magnetic responsiveness and serve as a cross-linking agent. The nanocomposite exhibited notable swelling capabilities, achieving equilibrium values of 706 g/g at pH 9 (25 °C) and 603 g/g at physiological temperature (37 °C, pH 7.4). Additionally, MNHNC demonstrated responsiveness to pH, temperature, and magnetic fields, facilitating controlled drug release. Using doxorubicin (DOX) as a model drug, MNHNC exhibited dual pH sensitivity (NG at pH 5.4 and MNHNC at pH 7.4) and achieved a prolonged release profile of 400 h, significantly surpassing conventional systems, including our previous nanocomposite. Release kinetics followed a super case-II transport mechanism, where swelling primarily governed drug diffusion. Furthermore, the application of a magnetic field enabled fine-tuning of the release rate, offering an additional layer of control. The kinetic study indicated that the drug release from MNHNC followed zero-order kinetics under certain conditions, ensuring a consistent release rate over time, which is highly desirable for maintaining therapeutic efficacy. The Korsmeyer-Peppas model further confirmed the super case-II transport mechanism, highlighting the significant influence of polymer relaxation and swelling on the release process. The Hixson-Crowell model also demonstrated the role of matrix erosion in the drug release mechanism. The results showed a marked improvement in pH and temperature sensitivity compared to previous formulations, enhanced mechanical stability due to the integration of Fe3O4 nanoparticles, and the ability to modulate drug release through external magnetic fields. In vitro cytotoxicity assessment using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay demonstrated the biocompatibility of the MNHNC, with over 95% cell viability in the absence of DOX, confirming its nontoxic nature. Upon DOX loading, MNHNC exhibited a proper anticancer effect against cancer cell lines, showing a dose-dependent reduction in cell viability. The robust mechanical stability, biocompatibility, and multistimuli responsiveness of MNHNC position it as a promising candidate for advanced, targeted drug delivery systems.

Progress in the mechanical properties of nanoparticles for tumor-targeting delivery

Cancer nanomedicines have attracted significant attention in the past several decades, and the physicochemical properties, such as the size, shape, composition, surface charge, hydrophobicity, and mechanical properties, of nanoparticles have been optimized for potent cancer therapy. Since publishing our 2020 tutorial review "Influence of nanomedicine mechanical properties on tumor targeting delivery" in Chemical Society Reviews, substantial advancements have been made in understanding the role of mechanical properties in cancer nanomedicine. Notably, in vivo transport processes that are dependent on the mechanical properties of nanomedicine, including long circulation, tumor accumulation, and deep penetration, have been extensively studied using various nano-drug delivery systems. These studies have demonstrated that leveraging these mechanical properties can significantly enhance the antitumor efficacy of nanomedicine. In this review, we categorize the advancements in the mechanical properties of cancer nanomedicine into three distinct themes: the interactions between nanoparticles with varied mechanical properties and cells (2002 - present), the impact of these properties on in vivo delivery processes (2007 - present), and the strategic use of mechanical properties to boost cancer therapy (2023 - present). We analyze how different mechanical properties of organic, inorganic, hybrid, and biological nanoparticles affect their delivery processes at the macroscopic level, i.e., in tissues, organs and cells. At the microscopic level, their biological and physical interactions with biological barriers, physiological structures, cell membranes, organelles, and other structures reveal the potential mechanism of nanoparticles' mechanical properties in determining their antitumor efficacy. Furthermore, we address the current challenges and future prospects in the mechanical properties of cancer nanomedicine, as well as the clinical translation potential of nanoparticles with diverse mechanical characteristics.

Microwave-Assisted N-Isopropylacrylamide Nanogel Synthesis: Exploring the Role of Reaction Parameters and Cross-linking Agents

This study provides a detailed account of the use of microwave-assisted synthesis as a novel and efficient method for preparing monodisperse poly(N-isopropylacrylamide) (PNIPAM) nanogels. The synthesis, based on free radical precipitation copolymerization of NIPAM and crosslinkers in water, was accelerated by microwave irradiation. Crosslinkers such as ethylene glycol dimethacrylate (EGDMA) and degradable bis-acryloylcystamine (BAC) were employed to study their effects on nanogel structure and properties, including their temperature-responsive behavior. HPLC analysis revealed differences in monomer and crosslinker conversion between the two agents. The growth of the nanogel particles was analyzed at various polymerization times using dynamic light scattering (DLS), ζ-potential measurements, and cryo-TEM imaging. The data showed that microwave-assisted synthesis reduced reaction time from 6 hours to minutes. BAC produced uniformly cross-linked nanogels, whereas EGDMA formed nanogels with dense cores and loose PNIPAM shells. Stability studies during storage and in biologically relevant media indicated their potential for biomedical applications.

Natural polysaccharide-small molecule smart responsive nanogels: Design, synthesis, and synergistic chemoimmunotherapy for tumors

Cancer poses a significant medical challenge worldwide. Research into tumor biology has revealed the prevalence of acidic conditions and abnormally high levels of reactive oxygen species (ROS) within the tumor microenvironment. In response to these findings, a ROS-responsive crosslinker, (((oxalylbis(oxy))bis(methylene))bis(4,1-phenylene))diboronic acid (OBA), was designed and synthesized using (4-hydroxymethyl)phenylboronic acid and ethanedioyl chloride as reactants. pH-responsive boronate ester bonds were formed between the diboronic acid groups of the crosslinker and the dihydroxyl groups of the naturally occurring active Astragalus polysaccharide (ASP). This resulted in the successful construction of pH/ROS dual-responsive nanogels (BAI@ASPOBA) loaded with the chemotherapeutic natural small molecule baicalein (BAI). Characterization of BAI@ASPOBA through molecular dynamics simulations and other methods demonstrated that it not only inhibited the proliferation of A549 tumor cells in vitro but also exhibited remarkable anti-tumor activity in vivo, along with excellent safety and biocompatibility. Further mechanistic studies revealed that the anti-tumor activity arises from the synergistic enhancement of the chemotherapeutic effects of BAI and the natural polysaccharide ASP. Specifically, the constructed BAI@ASPOBA nanogels enhanced the anti-tumor efficacy of BAI, while ASP, serving as the carrier for the nanomaterials, played an immunostimulatory role, facilitating tumor immunotherapy. The design and development of the novel BAI@ASPOBA nanogels in this study are anticipated to provide a new and effective treatment strategy for cancer therapy.

Biocompatible nanogels with tunable size and tailorable properties: A simple synthesis by self-assembly and disulfide crosslinking of amphiphilic hyperbranched peach gum polysaccharide

Polysaccharide nanogels (NGs) have shown considerable promise in a multitude of fields, owing to their compelling synergistic attributes. Despite this, simple synthesis of polysaccharide NGs that possess uniform and adjustable sizes, tailored properties, and superior biocompatibility remains a significant challenge. Natural peach gum polysaccharide (PGP), renowned for its outstanding biocompatibility and hyperbranched macromolecular structure, stands out as an excellent candidate for NGs preparation, though it has not yet been explored for this purpose. Herein, we present a facile and effective strategy for preparing PGP-based NGs (PGP-NGs) by leveraging the self-assembly and disulfide crosslinking techniques, without using any surfactants. The resultant PGP-NGs exhibit good aqueous dispersibility, enhanced colloidal stability, high biocompatibility and tunable size. Moreover, our strategy enables the direct creation of functional PGP-NGs to accommodate diverse applications by simultaneously modifying PGP with lipoic acid (LA) and other functional molecules, as confirmed by the synthesis of fluorescent PGP-RB-NGs in this study. These PGP-RB-NGs, with their bright fluorescence, efficient cellular internalization and low cytotoxicity, are promising for cell imaging applications. Additionally, the preparation of doxorubicin hydrochloride (DOX)-loaded PGP-NGs can be readily achieved through our strategy. This study thereby provides an effective strategy for constructing robust PGP-based NGs.

Inorganic nanoparticle-based nanogels and their biomedical applications

The advent of nanotechnology has brought tremendous progress in the field of biomedical science and opened avenues for advanced diagnostics and therapeutics applications. Several nanocarriers such as nanoparticles, liposomes, and nanogels have been designed to increase the drug efficiency and targeting ability in patients. Nanoparticles based on gold, silver, and iron are dominantly used for biomedical purposes owing to their biocompatibility properties. Nanoparticles offer an enhanced permeation into tissue vessels; however, their short half-life, toxicity, and off-site accumulations limit their functionality. The above shortcomings could be prevented by employing an integrated system combining nanoparticles with a nanogel-based system. These nanogels are 3D polymeric networks formed by physical and chemical crosslinking and are capable of incorporating nanoparticles, drugs, proteins, and genetic materials. Modification, functionalization, and introduction of inorganic nanoparticles have been shown to enhance the properties of nanogels, such as biocompatibility, stimuli responsiveness, stability, and selectivity. This review paper is focused on the design, synthesis, and biomedical application of inorganic nanoparticle-based nanogels. Current challenges and future perspectives will be briefly discussed to emphasize the versatile role of these multifunctional nanogels for therapeutic and diagnostic purposes.

Flavonoid-Based Nanogels: A Comprehensive Overview

The growing field of nanotechnology has recently given much attention to nanogels, which are versatile formulas and have promising biomedical applications. Nanogels or nanohydrogels have undergone significant development in various fields of biomedical and industrial research to meet increasing demands, such as in pharmaceuticals, cosmetics, food, and genetic engineering. Nanogels that contain flavonoids, which are secondary metabolites found in plants, are starting to become distinctive and reveal their unique characteristics. The objective of the article is to provide a comprehensive overview of recent research articles on flavonoid-based nanogels, emphasizing the general aspects regarding nanogel formulation and structural characterization, as well as the advancements made in the biomedical field. In conclusion, this article outlines up-to-date developments in the synthesis, formulation, structural characterization, and therapeutic applications of flavonoid-based nanogels, emphasizing their important role in the field of nanotechnology.

Carbohydrate-based polymer nanocarriers for environmentally friendly applications

Effective delivery of active substances and drugs is an important part of treatment. In order for a drug to work at the right place in the body, it must be transported there in the right way. For this reason, new carriers are being sought for active substances and drugs that can effectively deliver drugs to the target site without causing additional side effects. These include nanoparticles, microneedles, cubosomes and nanogels, among others. Recently, carriers based on biodegradable polymers such as hyaluronic acid or chitosan are becoming popular. In addition, modern carriers are designed to release the active ingredient in response to a specific agent. This paper reviews the literature from the past 5 years on novel delivery systems with medical, agricultural, food and cosmetic applications, with a special emphasis on the use of carbohydrate-based nanocarriers.

Biomimetic Molecularly Imprinted Nanogels for the Recognition of Spike Glycoproteins

The rapid spread and mutation of SARS-CoV-2, the virus responsible for COVID-19, has set the foundation for extensive research into next-generation therapeutic strategies. A critical component of SARS-CoV-2 is the trimeric Spike (S) glycoprotein, which facilitates viral entry into host cells by interacting with the receptor-binding domain (RBD). To inhibit and block viral entry, we designed and developed molecularly imprinted synthetic nanogel antibodies (MIP-SNAs) that cap the Spike S1 RBD. This aims to provide a versatile, biosecure, and effective therapeutic tool for the prevention and treatment of SARS-CoV-2 infection. Herein, we employed reverse miniemulsion polymerization to synthesize MIP-SNAs using poly(ethylene glycol) diacrylate (PEGDA), a nontoxic, nonimmunogenic and FDA-approved polymer, able to interact noncovalently with the functional groups of template Spike S1 RBD. In addition, the formulation of MIP-SNAs was based on a preliminary investigation of protein conformation by circular dichroism. Characterization of the SNAs was conducted using several techniques to investigate the chemical structure, thermal stability, size, and morphology. Under optimal conditions, the MIP-SNAs exhibited high specificity, with rebinding capacities up to 6-fold higher compared to the control nonimprinted synthetic nanogel antibodies. MIP-SNAs also demonstrated notable selectivity toward the SARS-CoV-2 Spike S1 RBD protein compared to the structural resembling Spike proteins of Bat-CoV, while cytocompatibility assays confirmed the biocompatible character of the SNAs. Given the excellent features of the recently developed MIP-SNAs, we are one step closer to finding efficient but also patient-friendly prevention and treatment solutions for SARS-CoV-2 infection. Beyond immediate applications, this technology offers the potential for broader diagnostic and therapeutic uses against related viral pathogens.

Sprayed Aqueous Microdroplets for Spontaneous Synthesis of Functional Microgels

The development of sustainable synthesis route to produce functional and bioactive polymer colloids has attracted much attention. Most strategies are based on the polymerization of monomers or crosslinking of prepolymers by enzyme- or cell-mediated reactions or specific catalysts in confined emulsions. Herein, a facile solution spray method was developed for spontaneous synthesis of microgels without use of confined emulsion, additional initiators/catalysts and deoxygenation, which addresses the challenges in traditional microgel synthesis. The polarization of air-water interface of the microdroplets can spontaneously split hydroxide ions in water to produce hydroxyl radicals, thereby initiating polymerization and crosslinking in air environment. This synthesis strategy is applicable to a variety of monomers and enables the fabrication of microgels with tunable chemical structures and variable sizes. Importantly, the synthesis route also allows for the preparation of enzyme- or drug-loaded microgels via the in situ encapsulation, which also display high enzymatic activity and stimuli-triggered drug release. Therefore, this work not only is of great significance to macromolecular science and microdroplet chemistry, but also may bring new insights into cellular biochemistry and even prebiotic chemistry due to the prevalence of microdroplets in the environment.

Nanogels-Innovative Drug Carriers for Overcoming Biological Membranes

Nanogels are promising drug delivery systems since they possess undeniable advantages such as high loading capacity for hydrophilic and hydrophobic drugs, stabilization of sensitive drugs, biocompatibility, and biodegradability. The present review summarizes experimental studies related to carriers, drug loading, and membrane transport of nanogels. In particular, the review discusses the properties, advantages, and limitations of polymeric carriers with respect to the behavior of the prepared nanogels in in vivo conditions. The potential of nanogel systems for encapsulation of hydrophilic or hydrophobic drugs and the mechanisms of loading and drug release are also emphasized. Moreover, the challenges related to nanogel transport through the barriers presented in parenteral, oral, ocular, nasal, and dermal routes of administration are also considered.

Polymeric nanocarriers for therapeutic gene delivery

The recent commercialization of gene products has sparked significant interest in gene therapy, necessitating efficient and precise gene delivery via various vectors. Currently, viral vectors and lipid-based nanocarriers are the predominant choices and have been extensively investigated and reviewed. Beyond these vectors, polymeric nanocarriers also hold the promise in therapeutic gene delivery owing to their versatile functionalities, such as improving the stability, cellar uptake and endosomal escape of nucleic acid drugs, along with precise delivery to targeted tissues. This review presents a brief overview of the status quo of the emerging polymeric nanocarriers for therapeutic gene delivery, focusing on key cationic polymers, nanocarrier types, and preparation methods. It also highlights targeted diseases, strategies to improve delivery efficiency, and potential future directions in this research area. The review is hoped to inspire the development, optimization, and clinical translation of highly efficient polymeric nanocarriers for therapeutic gene delivery.

Intelligent responsive nanogels: New Horizons in cancer therapy

Biologically engineered nanogels formed through sophisticated intramolecular crosslinking processes represent the forefront of next-generation drug delivery systems. These innovative systems offer many advantages, like adjustable size, satisfactory biocompatibility, and minimal toxicity. Their unique attributes facilitate deep penetration and long-term retention of drugs in tumors, effectively enhancing the anti-tumor effects. Nonetheless, the rapid disintegration of nanogels and the subsequent triggering of drug release at the tumor site pose significant challenges in achieving more effective and precise tumor treatments. Therefore, increasing research has been dedicated to exploring stimulus-responsive nanogels for enhancing tumor therapy. This review aims to encapsulate the research advancements in emerging stimulus-responsive antitumor nanogels. Firstly, a detailed exposition is provided on various endogenous stimulus-responsive nanogels, encompassing factors such as pH, hypoxia, enzymes, reactive oxygen species (ROS), and glutathione (GSH). Secondly, various nanogels triggered by exogenous stimuli such as light, ultrasound, temperature, and magnetic fields are elaborately presented. Furthermore, nanogels with multifaceted stimulus-responsive properties are also skillfully designed. Finally, the future directions, application prospects, and challenges of intelligent responsive nanogels in cancer treatment are highlighted.

Physiological, biochemical, apoptosis-linked gene expression, and histopathological insights in Nile catfish subjected to toxicity by magnetite nanogel

The target of this novel work is to assess the immunosuppression, genotoxicity, histopathological alterations, and cumulative mortality induced by acute toxicity of magnetite nanogel (MNG) in Nile catfish. Furthermore, a subsequent 10-day depuration period is adopted to estimate the restoration of those disturbed indices. Nile catfish (n = 180) were allotted into four groups and exposed to different concentrations of MNG (0, 1/10, 1/8, and 1/5 96-h LC50). The outcomes displayed a remarkable concentration-dependent decline in the immune indices level (LYZ, NO, and MPO). The gene expression of antioxidant (SOD) and apoptosis-regulatory genes (MAPK3 and JNK) was upregulated in MNG-exposed fish. Histopathological disruptions in the tissue architecture of gills and intestines were also evident in MNG-exposed groups. Interestingly, after a 10-day depuration period, marked improvement in the level of immune response mediators and gene expression of apoptotic genes was evident in all experimental groups, particularly at 1/10 of LC50. Overall, exposure to higher concentrations of MNG (1/5 and 1/8 of LC50) exerts multiple adverse influences on the Nile catfish, which were less pronounced at 1/10 of LC50. Surprisingly, a subsequent 10-day recuperation time was adequate for alleviating those impairments, with the maximum improvement in the Nile catfish exposed to 1/10 of LC50.

Strategies for Overcoming Bacterial Resistance to Nanoparticles: A Systematic Review

The increasing prevalence of bacterial resistance to conventional antimicrobial agents and nanoparticles (NPs) has become a critical global health challenge. This systematic review aimed to evaluate strategies for overcoming bacterial resistance to nanoparticles by synthesizing evidence on nanoparticle composition, functionalization, and targeted resistance mechanisms. A comprehensive literature search of studies published between 2000 and 2025 was conducted, focusing on experimental designs assessing antimicrobial efficacy, biofilm disruption, and efflux pump inhibition. The reviewed studies highlighted advanced nanoparticle formulations, including silver-cyanographene conjugates, lanthanum-functionalized graphene oxide, and carbon nanogels, which demonstrated enhanced efficacy against resistant bacterial strains. Key findings emphasized the role of surface functionalization, nanoparticle size modulation, and combination therapies in mitigating resistance. Functionalized nanoparticles effectively disrupted biofilm matrices, inhibited efflux pumps, and enhanced intracellular penetration, reducing bacterial survival rates. Despite promising results, challenges remain, including variability in nanoparticle formulations, limited scalability, and long-term ecological impacts. This review underscores the potential of innovative nanoparticle designs and combination therapies to combat bacterial resistance and emphasizes the need for standardized protocols and clinical translation.

The interaction of a self-assembled nanoparticle and a lipid membrane: Binding, disassembly and re-distribution

Here we report a detailed study of the interactions of nanoparticles, formed by the self-assembly of cholesterol-containing porphyrins, with lipid membranes. We show that the interaction is a two-step process: first, the docking and fusion, then, the redistribution of the building blocks of the self-assembled nanoparticles (SANs henceforth). Analysis of the binding and structural data is consistent with the docking step being driven by a multivalence cooperative effect and with the formation of SAN aggregates on the membrane, whilst the solubility of the cholesterol anchor in the membrane is key to both the fusion and redistribution of the SANs building blocks. The tendency of the SAN to aggregate in the membrane helps explain the photosensitizer properties of the SANs, essential to their anti-microbial activity. The solubility of the cholesteryl anchors drives fusion to the membrane and de-assembly of the SAN, explaining the capability of the SANs to deliver therapeutic cargos at the lipid interface. The subsequent redistribution of the SANs building blocks offer a plausible pathway to body clearance that is not immediately available to hard nanoparticles. These properties, and the modularity of the synthesis, point to the SANs being an excellent platform for the development of nanomedicines. An unexpected consequence of unraveling the mechanism of membrane interaction of these SANs is that it allows us to derive a value of the free energy of binding of cholesterol (the membrane anchor of the SAN building blocks) to a lipid membrane, that is consistent with the literature values. This is an additional property that can be exploited to determine the affinity of a variety of membrane anchors to membranes of various compositions.

Recent advances in near-infrared stimulated nanohybrid hydrogels for cancer photothermal therapy

Nanomedicine has emerged as a promising avenue for advancing cancer treatment, but the challenge of mitigating its in vivo side effects necessitates the development of innovative structures and materials. Recent investigation has unveiled nanogels as particularly compelling candidates, characterized by a porous, three-dimensional network architecture that exhibits exceptional drug loading capacity. Beyond this, nanogels boast a substantial specific surface area and can be tailored with specific chemical functionalities. Consequently, nanogels are frequently engineered as a multi-modal synergistic platform for combating cancer, wherein photothermal therapy stands out due to its capacity to penetrate deep tissues and achieve localized tumor eradication through the application of elevated temperatures. In this review, we delve into the synthesis of diverse varieties of photothermal nanogels capable of controlled drug release triggered by either chemical or physical stimuli. It also summarizes their potential for synergistic integration with photothermal therapy alongside other therapeutic modalities to realize effective tumor ablation. Moreover, we analyze the primary mechanisms underlying the contribution of photothermal nanogels to cancer treatment while underscoring their adeptness in regulating therapeutic temperatures for repairing bone defects resulting from tumor-associated trauma. Envisioned as an auspicious strategy in the realm of cancer therapy, photothermal nanogels hold promise for furnishing controlled drug delivery and precise thermal ablation capabilities.

Facile synthesis of size‐tunable multihydroxy nanogels by self‐assembly‐induced disulfide bonds crosslinking

Significant advancements have been achieved in polymer nanogel synthesis, yet there is a dearth of methods for easily preparing size‐adjustable, surface‐modifiable, and biocompatible nanogels. This study introduces a straightforward method for fabricating hyperbranched polyglycerol (HPG) nanogels in water through self‐assembly and disulfide bond crosslinking, avoiding the use of surfactants. The process involves modifying HPG with thioctic acid (TA) to create amphiphilic HPG‐TA rich in disulfide bonds, which is then reduced to facilitate water introduction and self‐assembly. Photocrosslinking is used to finalize the formation of HPG nanogels. These nanogels feature a uniform size distribution, with hydrodynamic diameters tunable from around 90 to 400 nm by tweaking synthesis variables. They have shown low cytotoxicity and high stability in aqueous media, with notable sensitivity to pH, especially in acidic conditions (e.g., pH 3), and redox‐responsiveness, as evidenced by reactions to 10 mM dithiothreitol (DTT). The nanogels' multiple hydroxyl groups enable easy functionalization, exemplified by the synthesis of fluorescent HPG‐RB nanogels. This work presents an efficient strategy for producing robust HPG nanogels, potentially spurring further advancements in the field of polymer nanogel synthesis and application.

Polysaccharide hydrogels for skin wound healing

Advances in the development and utilization of polysaccharide materials are highly promising, offering prominent applications in the field of tissue engineering for addressing diverse clinical needs, including wound healing, bone regeneration, cartilage repair, and treatment of conditions such as arthritis. Novel polysaccharide materials are popular owing to their inherent stability, biocompatibility, and repeatability. This review presents an overview of the biomedical applications of natural polysaccharide hydrogels and their derivatives. Herein, we discuss the latest advancements in the fabrication, physicochemical properties, and biomedical applications of polysaccharide-based hydrogels, including chitosan, hyaluronic acid, alginate, and cellulose. Various processing techniques applicable to polysaccharide materials are explored, such as the transformation of polysaccharide hydrogels into electrospun nanofibers, microneedles, microspheres, and nanogels. Furthermore, the use of polysaccharide hydrogels in the context of wound-healing applications, including hemostatic effects, antimicrobial activities, anti-inflammatory properties, and promotion of angiogenesis, is presented. Finally, we address the challenges encountered in the development of polysaccharide hydrogels and outline the potential prospects in this evolving field.

Fisetin-loaded pluronic-based nanogel: Radiation synthesis for alleviating neurocognitive impairments in a rat model of alzheimer's disease via modulation of the apoptotic cascade

Alzheimer's disease (AD) is a neurodegenerative disorder marked by cognitive impairment and memory loss. In this study, AD was experimentally induced in rats using aluminum chloride (AlCl3) and D-galactose (D-gal). Fisetin (Fis), a natural compound with antioxidant and anti-inflammatory properties, has potential for neurodegeneration management, but its low bioavailability limits clinical applications. To address this, we synthesized and characterized Pluronic-2-Acrylamido-2-methylpropane sulfonic acid (PLUR-PAMPS) nanogels using gamma radiation and successfully loaded Fis onto them (Fis-PLUR-PAMPS). The optimal formulation exhibited minimal particle size, a highly acceptable polydispersity index, and the highest zeta-potential, enhancing stability and solubilization efficiency. Our goal was to improve Fis's bioavailability and assess its efficacy against AlCl3/D-gal-induced AD. Male albino Wistar rats were pre-treated orally with Fis (40 mg/kg) or Fis-PLUR-PAMPS for seven days, followed by a seven-day intraperitoneal injection of AlCl3 and D-gal. Behavioral assessments, histopathological analysis, and biochemical evaluation of markers related to AD pathology were conducted. Results demonstrated that Fis-PLUR-PAMPS effectively mitigated cognitive impairments and neurodegenerative signs induced by AlCl3/D-gal. These findings suggest that Fis-PLUR-PAMPS nanogels enhance Fis's bioavailability and therapeutic efficacy, offering a promising approach for AD management.

Nanogels: Recent Advances in Synthesis and Biomedical Applications

In the context of advanced nanomaterials research, nanogels (NGs) have recently gained broad attention for their versatility and promising biomedical applications. To date, a significant number of NGs have been developed to meet the growing demands in various fields of biomedical research. Summarizing preparation methods, physicochemical and biological properties, and recent applications of NGs may be useful to help explore new directions for their development. This article presents a comprehensive overview of the latest NG synthesis methodologies, highlighting advances in formulation with different types of hydrophilic or amphiphilic polymers. It also underlines recent biomedical applications of NGs in drug delivery and imaging, with a short section dedicated to biosafety considerations of these innovative nanomaterials. In conclusion, this article summarizes recent innovations in NG synthesis and their numerous applications, highlighting their considerable potential in the biomedical field.

In-situ-formed immunotherapeutic and hemostatic dual drug-loaded nanohydrogel for preventing postoperative recurrence of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent malignancy characterized by an exceedingly high recurrence rate post-surgery, significantly impairing the prognosis of HCC patients. However, a standard in-care strategy for postoperative therapy is still lacking. Although encouraging results have been obtained in a newly published clinical trial for postoperative therapy by targeting the vascular endothelial growth factor (VEGF) and programmed death ligand 1 (anti-PD-L1), its efficacy remains constrained. Combining a hemostatic hydrogel with a nanoparticle-based drug delivery system presents an opportunity to optimize the antitumor effect. Herein, we developed a nanoplatform, termed HMSN@Sor/aP@Gel, comprising a hemostatic fibrin hydrogel and functionalized hollow mesoporous silica nanoparticles (HMSNs) loaded with sorafenib and anti-PD-L1 for locally administered targeted-immunotherapy to prevent the postoperative recurrence and metastasis of HCC. The antitumor mechanism is grounded in dual inhibition of Ras/Raf/MEK/ERK (MAPK) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) pathways, synergistically complemented by PD-L1 blockade. HMSN@Sor/aP@Gel facilitates dendritic cell maturation, enhances cytotoxic T-lymphocyte infiltration, promotes the polarization of tumor-associated macrophages to M1 phenotype, induces tumor immunogenic cell death, reverses immunosuppression, and establishes immune memory to counter postoperative recurrence. Animal studies corroborate that HMSN@Sor/aP@Gel-mediated targeted immunotherapy significantly impedes primary and metastatic tumor growth and establishes immune memory to prevent recurrence post-surgery. This investigation presents a promising strategy for postoperative therapy with considerable potential for clinical translation.

Nanogel-based nitric oxide-driven nanomotor for deep tissue penetration and enhanced tumor therapy

Antitumor agents often lack effective penetration and accumulation to achieve high therapeutic efficacy in treating solid tumors. Nanomotor-based nanomaterials offer a potential solution to address this obstacle. Among them, nitric oxide (NO) based nanomotors have garnered attention for their potential applications in nanomedicine. However, there widespread clinical adoption has been hindered by their complex preparation processes. To address this limitation, we have developed a NO-driven nanomotor utilizing a convenient and scalable nanogel preparation procedure. These nanomotors, loaded with the fluorescent probe / sonosensitizer chlorin e6 (Ce6), were specifically engineered for sonodynamic therapy. Through comprehensive in vitro investigations using both 2D and 3D cell models, as well as in vivo analysis of Ce6 fluorescent signal distribution in solid tumor models, we observed that the self-propulsion of these nanomotors significantly enhances cellular uptake and tumor penetration, particularly in solid tumors. This phenomenon enables efficient access to challenging tumor regions and, in some cases, results in complete tumor coverage. Notably, our nanomotors have demonstrated long-term in vivo biosafety. This study presents an effective approach to enhancing drug penetration and improving therapeutic efficacy in tumor treatment, with potential clinical relevance for future applications.

Hydrogels Based on Proteins Cross-Linked with Carbonyl Derivatives of Polysaccharides, with Biomedical Applications

Adding carbonyl groups into the hydrogel matrix improves the stability and biocompatibility of the hydrogels, making them suitable for different biomedical applications. In this review article, we will discuss the use of hydrogels based on polysaccharides modified by oxidation, with particular attention paid to the introduction of carbonyl groups. These hydrogels have been developed for several applications in tissue engineering, drug delivery, and wound healing. The review article discusses the mechanism by which oxidized polysaccharides can introduce carbonyl groups, leading to the development of hydrogels through cross-linking with proteins. These hydrogels have tunable mechanical properties and improved biocompatibility. Hydrogels have dynamic properties that make them promising biomaterials for various biomedical applications. This paper comprehensively analyzes hydrogels based on cross-linked proteins with carbonyl groups derived from oxidized polysaccharides, including microparticles, nanoparticles, and films. The applications of these hydrogels in tissue engineering, drug delivery, and wound healing are also discussed.

Functional Nanomaterials for the Treatment of Osteoarthritis

Osteoarthritis (OA) is the most common degenerative joint disease, affecting more than 595 million people worldwide. Nanomaterials possess superior physicochemical properties and can influence pathological processes due to their unique structural features, such as size, surface interface, and photoelectromagnetic thermal effects. Unlike traditional OA treatments, which suffer from short half-life, low stability, poor bioavailability, and high systemic toxicity, nanotherapeutic strategies for OA offer longer half-life, enhanced targeting, improved bioavailability, and reduced systemic toxicity. These advantages effectively address the limitations of traditional therapies. This review aims to inspire researchers to develop more multifunctional nanomaterials and promote their practical application in OA treatment.

Self-Assembled Nanocarrier Delivery Systems for Bioactive Compounds

Although bioactive compounds (BCs) have many important functions, their applications are greatly limited due to their own defects. The development of nanocarriers (NCs) technology has gradually overcome the defects of BCs. NCs are equally important as BCs to some extent. Self-assembly (SA) methods to build NCs have many advantages than chemical methods, and SA has significant impact on the structure and function of NCs. However, the relationship among SA mechanism, structure, and function has not been given enough attention. Therefore, from the perspective of bottom-up building mechanism, the concept of SA-structure-function of NCs is emphasized to promote the development of SA-based NCs. First, the conditions and forces for occurring SA are introduced, and then the SA basis and molecular mechanism of protein, polysaccharide, and lipid are summarized. Then, varieties of the structures formed based on SA are introduced in detail. Finally, facing the defects of BCs and how to be well solved by NCs are also elaborated. This review attempts to describe the great significance of constructing artificial NCs to deliver BCs from the aspects of SA-structure-function, so as to promote the development of SA-based NCs and the wide application of BCs.

Recent Research Progress on Polyamidoamine-Engineered Hydrogels for Biomedical Applications

Hydrogels are three-dimensional crosslinked functional materials with water-absorbing and swelling properties. Many hydrogels can store a variety of small functional molecules to structurally and functionally mimic the natural extracellular matrix; hence, they have been extensively studied for biomedical applications. Polyamidoamine (PAMAM) dendrimers have an ethylenediamine core and a large number of peripheral amino groups, which can be used to engineer various polymer hydrogels. In this review, an update on the progress of using PAMAM dendrimers for multifunctional hydrogel design was given. The synthesis of these hydrogels, which includes click chemistry reactions, aza-Michael addition, Schiff base reactions, amidation reactions, enzymatic reactions, and radical polymerization, together with research progress in terms of their application in the fields of drug delivery, tissue engineering, drug-free tumor therapy, and other related fields, was discussed in detail. Furthermore, the biomedical applications of PAMAM-engineered nano-hydrogels, which combine the advantages of dendrimers, hydrogels, and nanoparticles, were also summarized. This review will help researchers to design and develop more functional hydrogel materials based on PAMAM dendrimers.

pH-Responsive Nanogels Generated by Polymerization-Induced Self-Assembly of a Succinate-Functional Monomer

Colloidal nanogels formed from a pH-responsive poly(succinate)-functional core and a poly(sulfonate)-functional corona were prepared via a previously unreported reversible addition-fragmentation chain-transfer (RAFT)-mediated aqueous emulsion polymerization-induced self-assembly (PISA) route. Specifically, a poly(potassium 3-sulfopropyl methacrylate) (PKSPMA50) macromolecular chain-transfer agent (macro-CTA) was synthesized via RAFT solution polymerization followed by chain-extension with a hydrophobic, carboxylic acid-functional, 2-(methacryloyloxy) ethyl succinate (MES) monomer at pH 2. Colloidal nanoparticles with tunable diameters between 66 to 150 nm, depending on the core composition, and narrow particle size distributions were obtained at 20% w/w solids. Well-defined pH-responsive nanogels that swell on increasing the pH could be prepared even without the addition of a cross-linking comonomer, and introducing an additional cross-linker to the core led to smaller nanogels with lower swelling ratios. These nanogels could reversibly change in size on cycling the pH between acidic and basic conditions and remain colloidally stable over a wide pH range and at 70 °C.

Retention of Ciprofloxacin and Carbamazepine from Aqueous Solutions Using Chitosan-Based Cryostructured Composites

Water pollution is becoming a great concern at the global level due to highly polluted effluents, which are charged year by year with increasing amounts of organic residues, dyes, pharmaceuticals and heavy metals. For some of these pollutants, the industrial treatment of wastewater is still relevant. Yet, in some cases, such as pharmaceuticals, specific treatment schemes are urgently required. Therefore, the present study describes the synthesis and evaluation of promising cryostructured composite adsorbents based on chitosan containing native minerals and two types of reinforcement materials (functionalized kaolin and synthetic silicate microparticles). The targeted pharmaceuticals refer to the ciprofloxacin (CIP) antibiotic and the carbamazepine (CBZ) drug, for which the current water treatment process seem to be less efficient, making them appear in exceedingly high concentrations, even in tap water. The study reveals first the progress made for improving the mechanical stability and resilience to water disintegration, as a function of pH, of chitosan-based cryostructures. Further on, a retention study shows that both pharmaceuticals are retained with high efficiency (up to 85.94% CIP and 86.38% CBZ) from diluted aqueous solutions.

Improvement of the Antioxidant and Antitumor Activities of Benzimidazole-Chitosan Quaternary Ammonium Salt on Drug Delivery Nanogels

The present study focused on the design and preparation of acid-responsive benzimidazole-chitosan quaternary ammonium salt (BIMIXHAC) nanogels for a controlled, slow-release of Doxorubicin HCl (DOX.HCl). The BIMIXHAC was crosslinked with sodium tripolyphosphate (TPP) using the ion crosslinking method. The method resulted in nanogels with low polydispersity index, small particle size, and positive zeta potential values, indicating the good stability of the nanogels. Compared to hydroxypropyl trimethyl ammonium chloride chitosan-Doxorubicin HCl-sodium tripolyphosphate (HACC-D-TPP) nanogel, the benzimidazole-chitosan quaternary ammonium salt-Doxorubicin HCl-sodium tripolyphosphate (BIMIXHAC-D-TPP) nanogel show higher drug encapsulation efficiency and loading capacity (BIMIXHAC-D-TPP 93.17 ± 0.27% and 31.17 ± 0.09%), with acid-responsive release profiles and accelerated release in vitro. The hydroxypropyl trimethyl ammonium chloride chitosan-sodium tripolyphosphate (HACC-TPP), and benzimidazole-chitosan quaternary ammonium salt-sodium tripolyphosphate (BIMIXHAC-TPP) nanogels demonstrated favorable antioxidant capability. The assay of cell viability, measured by the MTT assay, revealed that nanogels led to a significant reduction in the cell viability of two cancer cells: the human lung adenocarcinoma epithelial cell line (A549) and the human breast cancer cell line (MCF-7). Furthermore, the BIMIXHAC-D-TPP nanogel was 2.96 times less toxic than DOX.HCl to the mouse fibroblast cell line (L929). It was indicated that the BIMIXHAC-based nanogel with enhanced antioxidant and antitumor activities and acidic-responsive release could serve as a potential nanocarrier.