Preparation and use of nanogels as carriers of drugs

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.

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.

Cancer Nanovaccines: Nanomaterials and Clinical Perspectives

Cancer nanovaccines represent a promising frontier in cancer immunotherapy, utilizing nanotechnology to augment traditional vaccine efficacy. This review comprehensively examines the current state-of-the-art in cancer nanovaccine development, elucidating innovative strategies and technologies employed in their design. It explores both preclinical and clinical advancements, emphasizing key studies demonstrating their potential to elicit robust anti-tumor immune responses. The study encompasses various facets, including integrating biomaterial-based nanocarriers for antigen delivery, adjuvant selection, and the impact of nanoscale properties on vaccine performance. Detailed insights into the complex interplay between the tumor microenvironment and nanovaccine responses are provided, highlighting challenges and opportunities in optimizing therapeutic outcomes. Additionally, the study presents a thorough analysis of ongoing clinical trials, presenting a snapshot of the current clinical landscape. By curating the latest scientific findings and clinical developments, this study aims to serve as a comprehensive resource for researchers and clinicians engaged in advancing cancer immunotherapy. Integrating nanotechnology into vaccine design holds immense promise for revolutionizing cancer treatment paradigms, and this review provides a timely update on the evolving landscape of cancer nanovaccines.

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.

Hybrid Nanogel Drug Delivery Systems: Transforming the Tumor Microenvironment through Tumor Tissue Editing

The future of drug delivery offers immense potential for the creation of nanoplatforms based on nanogels. Nanogels present a significant possibility for pharmaceutical advancements because of their excellent stability and effective drug-loading capability for both hydrophobic and hydrophilic agents. As multifunctional systems, composite nanogels demonstrate the capacity to carry genes, drugs, and diagnostic agents while offering a perfect platform for theranostic multimodal applications. Nanogels can achieve diverse responsiveness and enable the stimuli-responsive release of chemo-/immunotherapy drugs and thus reprogramming cells within the TME in order to inhibit tumor proliferation, progression, and metastasis. In order to achieve active targeting and boost drug accumulation at target sites, particular ligands can be added to nanogels to improve the therapeutic outcomes and enhance the precision of cancer therapy. Modern "immune-specific" nanogels also have extra sophisticated tumor tissue-editing properties. Consequently, the introduction of a multifunctional nanogel-based drug delivery system improves the targeted distribution of immunotherapy drugs and combinational therapeutic treatments, thereby increasing the effectiveness of tumor therapy.

Advances in Nanoparticles in the Prevention and Treatment of Myocardial Infarction

Myocardial infarction (MI) is one of the most prevalent types of cardiovascular disease. During MI, myocardial cells become ischemic and necrotic due to inadequate blood perfusion, leading to irreversible damage to the heart. Despite the development of therapeutic strategies for the prevention and treatment of MI, their effects are still unsatisfactory. Nanoparticles represent a new strategy for the pre-treatment and treatment of MI, and novel multifunctional nanoparticles with preventive and therapeutic capabilities hold promise for the prevention and treatment of this disease. This review summarizes the common types and properties of nanoparticles, and focuses on the research progress of nanoparticles for the prevention and treatment of MI.

Nanocomposites used in the treatment of skin lesions: a scoping review

OBJECTIVE

To map the nanocomposites used in the treatment of skin lesions.

METHOD

A scoping review, according to the Joanna Briggs Institute methodology, carried out on eight databases, a list of references and Google Scholar to answer the question: "Which nanocomposites are used as a cover for the treatment of skin lesions?". Two independent reviewers selected the final sample using inclusion/exclusion criteria using the EndNote® and Rayyan programs. Data was extracted using an adapted form and reported using the PRISMA checklist extension, and the protocol was registered in the Open Science Framework (OSF).

RESULTS

21 articles were selected, with nanofibers, nanogels and nanomembranes as the nanocomposites described in wound healing, alone or in association with other therapies: negative pressure and elastic. Silver nanomaterials stand out in accelerating healing due to their antimicrobial and anti-inflammatory action, but caution should be exercised due to the risk of cytotoxicity and microbial resistance.

CONCLUSION

Nanocomposites used in wound treatment are effective in accelerating healing and reducing costs, and the addition of bioactives to nanomaterials has added extra properties that contribute to healing.

Oral Delivery of Photopolymerizable Nanogels Loaded with Gemcitabine for Pancreatic Cancer Therapy: Formulation Design, and in vitro and in vivo Evaluations

Background

Gemcitabine (GEM) faces challenges of poor oral bioavailability and extensive first-pass metabolism. Currently, only injectable formulations are available for clinical use. Hence, there is an urgent demand for the development of advanced, efficacious, and user-friendly dosage forms to maintain its status as the primary treatment for pancreatic ductal adenocarcinoma (PDAC). Nanogels (NGs) offer a novel oral drug delivery system, ideal for hydrophilic compounds like GEM. This study aims to develop NGs tailored for GEM delivery, with the goal of enhancing cellular uptake and gastrointestinal permeability for improved administration in PDAC patients.

Methods

We developed cross-linked NGs via photopolymerization of methacryloyl for drug delivery of GEM. We reveal characterization, cytotoxicity, and cellular uptake studies in Caco-2 and MIA PaCa-2 cells. In addition, studies of in vitro permeability and pharmacokinetics were carried out to evaluate the bioavailability of the drug.

Results

Our results show NGs, formed via photopolymerization of methacryloyl, had a spherical shape with a size of 233.91±7.75 nm. Gemcitabine-loaded NGs (NGs-GEM) with 5% GelMA exhibited efficient drug loading (particle size: 244.07±19.52 nm). In vitro drug release from NGs-GEM was slower at pH 1.2 than pH 6.8. Cellular uptake studies indicated significantly enhanced uptake in both MIA PaCa-2 and Caco-2 cells. While there was no significant difference in GEM's AUC and Cmax between NGs-GEM and free-GEM groups, NGs-GEM showed markedly lower dFdU content (10.07 hr∙μg/mL) compared to oral free-GEM (19.04 hr∙μg/mL) after oral administration (p<0.01), highlighting NGs' efficacy in impeding rapid drug metabolism and enhancing retention.

Conclusion

In summary, NGs enhance cellular uptake, inhibit rapid metabolic degradation of GEM, and prolong retention after oral administration. These findings suggest NGs-GEM as a promising candidate for clinical use in oral pancreatic cancer therapy.

Nanogels: Smart tools to enlarge the therapeutic window of gene therapy

Gene therapy can potentially treat a great number of diseases, from cancer to rare genetic disorders. Very recently, the development and emergency approval of nucleic acid-based COVID-19 vaccines confirmed its strength and versatility. However, gene therapy encounters limitations due to the lack of suitable carriers to vectorize therapeutic genetic material inside target cells. Nanogels are highly hydrated nano-size crosslinked polymeric networks that have been used in many biomedical applications, from drug delivery to tissue engineering and diagnostics. Due to their easy production, tunability, and swelling properties they have called the attention as promising vectors for gene delivery. In this review, nanogels are discussed as vectors for nucleic acid delivery aiming to enlarge gene therapy's therapeutic window. Recent works highlighting the optimization of inherent transfection efficiency and biocompatibility are reviewed here. The importance of the monomer choice, along with the internal structure, surface decoration, and responsive features are outlined for the different transfection modalities. The possible sources of toxicological endpoints in nanogels are analyzed, and the strategies to limit them are compared. Finally, perspectives are discussed to identify the remining challenges for the nanogels before their translation to the market as transfection agents.

Polymeric Nanohydrogel in Topical Drug Delivery System

Nanohydrogels (NH) are biodegradable polymers that have been extensively studied and utilized for various biomedical applications. Drugs in a topical medication are absorbed via the skin and carried to the intended location, where they are metabolized and eliminated from the body. With a focus on their pertinent contemporary treatments, this review aims to give a complete overview of recent advances in the creation and application of polymer NH in biomedicine. We will explore the key features that have driven advances in nanotechnology and discuss the significance of nanohydrogel-based formulations as vehicles for delivering therapeutic agents topically. The review will also cover the latest findings and references from the literature to support the advancements in nanotechnological technology related to the preparation and application of NH. In addition, we will also discuss the unique properties and potential applications of NH as drug delivery systems (DDS) for skin applications, underscoring their potential for effective topical therapeutic delivery. The challenge lies in efficiently delivering drugs through the skin's barrier to specific areas with high control. Environmentally sensitive systems, like polymer-based NH, show promise in treating dermatological conditions. Polymers are pivotal in developing these drug delivery systems, with NH offering advantages such as versatile drug loading, controlled release, and enhanced skin penetration.

Emerging trends in the application of hydrogel-based biomaterials for enhanced wound healing: A literature review

Currently, there is a rising global incidence of diverse acute and chronic wounds, underscoring the immediate necessity for research and treatment advancements in wound repair. Hydrogels have emerged as promising materials for wound healing due to their unique physical and chemical properties. This review explores the classification and characteristics of hydrogel dressings, innovative preparation strategies, and advancements in delivering and releasing bioactive substances. Furthermore, it delves into the functional applications of hydrogels in wound healing, encompassing areas such as infection prevention, rapid hemostasis and adhesion adaptation, inflammation control and immune regulation, granulation tissue formation, re-epithelialization, and scar prevention and treatment. The mechanisms of action of various functional hydrogels are also discussed. Finally, this article also addresses the current limitations of hydrogels and provides insights into their potential future applications and upcoming innovative designs.

Biopolymeric Nanogel as a Drug Delivery System for Doxorubicin-Improved Drug Stability and Enhanced Antineoplastic Activity in Skin Cancer Cells

In this study, doxorubicin was loaded in a chitosan-albumin nanogel with the aim of improving its stability and exploring the potential of the system in the treatment of skin cancer. Infrared spectroscopy and X-ray diffraction confirmed the encapsulation of the drug. Transmission electron microscopy revealed the spherical shape of the nanogel particles. The drug-loaded nanogel was characterized with a small diameter of 29 nm, narrow polydispersity (0.223) and positive zeta potential (+34 mV). The exposure of encapsulated doxorubicin to light (including UV irradiation and daylight) did not provoke any degradation, whereas the nonencapsulated drug was significantly degraded. In vitro studies on keratinocytes (HaCaT) and epidermoid squamous skin carcinoma cells (A-431) disclosed that the encapsulated doxorubicin was more cytotoxic on both cell lines than the pure drug was. More importantly, the cytotoxic concentration of encapsulated doxorubicin in carcinoma cells was approximately two times lower than that in keratinocytes, indicating that it would not affect them. Thus, the loading of doxorubicin into the developed chitosan-albumin nanogel definitely stabilized the drug against photodegradation and increased its antineoplastic effect on the skin cancer cell line.

Recent advances in stimuli-responsive tailored nanogels for cancer therapy; from bench to personalized treatment

To improve the quality of health in a personalized manner, better control over pharmacologically relevant cargo formulation, organ-specific targeted delivery, and on-demand release of therapeutic agents is crucial. Significant work has been put into designing and developing revolutionary nanotherapeutics approaches for the effective monitoring and personalized treatment of disease. Nanogel (NG) has attracted significant interest because of its tremendous potential in cancer therapy and its environmental stimuli responsiveness. NG is considered a next-generation delivery technology due to its benefits like as size tunability, high loading, stimuli responsiveness, prolonged drug release via in situ gelling mechanisms, stability, and its potential to provide personalized therapy from the investigation of human genes and the genes in various types of cancers and its association with a selective anticancer drug. Stimuli-responsive NGs can be used as smart nanomedicines to detect and treat cancer and can be tuned as personalized medicine as well. This comprehensive review article's major objectives include the challenges of NGs' clinical translation for cancer treatment as well as its early preclinical successes and prospects.

Developments in Emerging Topical Drug Delivery Systems for Ocular Disorders

According to the current information, using nano gels in the eyes have therapeutic benefits. Industry growth in the pharmaceutical and healthcare sectors has been filled by nanotechnology. Traditional ocular preparations have a short retention duration and restricted drug bioavailability because of the eye's architectural and physiological barriers, a big issue for physicians, patients, and chemists. In contrast, nano gels can encapsulate drugs within threedimensional cross-linked polymeric networks. Because of their distinctive structural designs and preparation methods, they can deliver loaded medications in a controlled and sustained manner, enhancing patient compliance and therapeutic efficacy. Due to their excellent drugloading capacity and biocompatibility, nano-gels outperform other nano-carriers. This study focuses on using nano gels to treat eye diseases and provides a brief overview of their creation and response to stimuli. Our understanding of topical drug administration will be advanced using nano gel developments to treat common ocular diseases such as glaucoma, cataracts, dry eye syndrome, bacterial keratitis, and linked medication-loaded contact lenses and natural active ingredients.

Cancer cell membrane biomimetic nanosystem for homologous targeted dual-mode imaging and combined therapy

HYPOTHESIS

The use of tumor cell membrane-camouflaged nanoparticles, specifically the multifunctional biomimetic core-shell nanosystem MPCONPs, can enhance the targeting ability and immune escape functionality of traditional chemotherapy, leading to more precise drug delivery and improved treatment outcomes.

EXPERIMENTS

Preparation of MPCONPs: Autologous tumor cell membrane (CM) fragments are collected and used to create a shell for the nanoparticles. A trypsin-sensitive cationic polylysine framework is synthesized and embedded with oxaliplatin (l-OHP) and Ce6-AuNDs (a singlet oxygen generator). The MPCONPs are formed by assembling these components.

FINDINGS

MPCONPs, as nanoparticles camouflaged with tumor CM, have enhanced cellular uptake in cancer cells and improved the efficacy of photodynamic therapy (PDT) and chemotherapy (CT). This offers great potential for their use as individualized therapeutic agents for clinical oncology treatment.

Oral Administration of Platinum Nanoparticles with SOD/CAT Cascade Catalytic Activity to Alleviate Ulcerative Colitis

Ulcerative colitis (UC) is a refractory chronic inflammatory disease involving the colon and rectum, falling under the category of inflammatory bowel disease (IBD). The accumulation of reactive oxygen species (ROS) in local tissues has been identified as a crucial contributor to the escalation of inflammatory responses. Therefore, eliminating ROS in the inflamed colon is a promising approach to treating UC. Nanomaterials with intrinsic enzyme-like activities (nanozymes) have shown significant therapeutic potential in UC. In this study, we found that platinum nanoparticles (Pt NPs) exhibited remarkable superoxide dismutase (SOD) and catalase (CAT) cascade catalytic activities, as well as effective hydroxyl radical (•OH) scavenging ability. The in vitro experiments showed that Pt NPs could eliminate excessive ROS to protect cells against oxidative stress. In the colitis model, oral administration of Pt NPs (loaded in chitosan/alginate hydrogel) could significantly alleviate UC, including reducing the colon length, the damaged epithelium, and the infiltration of inflammatory cells. Without appreciable systemic toxicity, Pt NPs represent a novel therapeutic approach to UC and are expected to achieve long-term inflammatory remission.

The Application of Nanogels as Efficient Drug Delivery Platforms for Dermal/Transdermal Delivery

The delivery of active molecules via the skin seems to be an efficient technology, given the various disadvantages of oral drug administration. Skin, which is the largest human organ of the body, has the important role of acting as a barrier for pathogens and other molecules including drugs; in fact, it serves as a primary defense system blocking any particle from entering the body. Therefore, to overcome the skin barriers and poor skin permeability, researchers implement novel carriers which can effectively carry out transdermal delivery of the molecules. Another significant issue which medical society tries to solve is the effective dermal delivery of molecules especially for topical wound delivery. The application of nanogels is only one of the available approaches offering promising results for both dermal and transdermal administration routes. Nanogels are polymer-based networks in nanoscale dimensions which have been explored as potent carriers of poorly soluble drugs, genes and vaccines. The nanogels present unique physicochemical properties, i.e., high surface area, biocompatibility, etc., and, importantly, can improve solubility. In this review, authors aimed to summarize the available applications of nanogels as possible vehicles for dermal and transdermal delivery of active pharmaceutical ingredients and discuss their future in the pharmaceutical manufacturing field.

Chitosan/Alginate Nanogels Containing Multicore Magnetic Nanoparticles for Delivery of Doxorubicin

In this study, multicore-like iron oxide (Fe3O4) and manganese ferrite (MnFe2O4) nanoparticles were synthesized and combined with nanogels based on chitosan and alginate to obtain a multimodal drug delivery system. The nanoparticles exhibited crystalline structures and displayed sizes of 20 ± 3 nm (Fe3O4) and 11 ± 2 nm (MnFe2O4). The Fe3O4 nanoparticles showed a higher saturation magnetization and heating efficiency compared with the MnFe2O4 nanoparticles. Functionalization with citrate and bovine serum albumin was found to improve the stability and modified surface properties. The nanoparticles were encapsulated in nanogels, and provided high drug encapsulation efficiencies (~70%) using doxorubicin as a model drug. The nanogels exhibited sustained drug release, with enhanced release under near-infrared (NIR) laser irradiation and acidic pH. The nanogels containing BSA-functionalized nanoparticles displayed improved sustained drug release at physiological pH, and the release kinetics followed a diffusion-controlled mechanism. These results demonstrate the potential of synthesized nanoparticles and nanogels for controlled drug delivery, offering opportunities for targeted and on-demand release in biomedical applications.

Advances in Nanogels for Topical Drug Delivery in Ocular Diseases

Nanotechnology has accelerated the development of the pharmaceutical and medical technology fields, and nanogels for ocular applications have proven to be a promising therapeutic strategy. Traditional ocular preparations are restricted by the anatomical and physiological barriers of the eye, resulting in a short retention time and low drug bioavailability, which is a significant challenge for physicians, patients, and pharmacists. Nanogels, however, have the ability to encapsulate drugs within three-dimensional crosslinked polymeric networks and, through specific structural designs and distinct methods of preparation, achieve the controlled and sustained delivery of loaded drugs, increasing patient compliance and therapeutic efficiency. In addition, nanogels have higher drug-loading capacity and biocompatibility than other nanocarriers. In this review, the main focus is on the applications of nanogels for ocular diseases, whose preparations and stimuli-responsive behaviors are briefly described. The current comprehension of topical drug delivery will be improved by focusing on the advances of nanogels in typical ocular diseases, including glaucoma, cataracts, dry eye syndrome, and bacterial keratitis, as well as related drug-loaded contact lenses and natural active substances.

Gum arabic/guar gum stabilized Hydnocarpus wightiana oil nanohydrogel: Characterization, antimicrobial, anti-inflammatory, and anti-biofilm activities

Hydnocarpus wightiana oil has proven to inhibit the growth of pathogenic microorganisms; however, the raw form is highly susceptible to oxidation, and thus it becomes toxic when uptake is in high amounts. Therefore, to minimize the deterioration, we formulated Hydnocarpus wightiana oil-based nanohydrogel and studied its characteristics as well biological activity. The low energy-assisted hydrogel was formulated by including gelling agent, connective linker, and cross-linker and it resulted in internal micellar polymerization of the milky white emulsion. The oil showed the presence of octanoic acid, n-tetradecane, methyl 11-(2-cyclopenten-1-yl) undecanoate (methyl hydnocarpate), 13-(2-cyclopenten-1-yl) tridecanoic acid (methyl chaulmoograte), and 10,13-eicosadienoic acid. The amount of caffeic acid was 0.0636 mg/g, which was higher than the amount of gallic acid (0.0076 mg/g) in the samples. The formulated nanohydrogel showed an average droplet size of 103.6 nm with a surface charge of -17.6 mV. The minimal inhibitory bactericidal, and fungicidal concentrations of nanohydrogel against pathogenic bacteria and fungi were ranging from 0.78 to 1.56 μl/mL with 70.29-83.62 % antibiofilm activity. Also, nanohydrogel showed a significantly (p < 0.05) higher killing rate for Escherichia coli (7.89 log CFU/mL) than Staphylococcus aureus (7.81 log CFU/mL) with comparable anti-inflammatory activity than commercial standard (49.28-84.56 %). Therefore, it can be concluded that being hydrophobic, and having the capability of target-specific drug absorption as well as biocompatibility nanohydrogels can be utilized to cure various pathogenic microbial infections.

Green synthesis of quaternized chitosan nanogel using emulsion-photopolymerization as redox-responsive drug carrier

We report the green synthesis of trimethyl chitosan-functionalized poly(2-hydroxyethyl methacrylate) (PHEMA-TMC) nanogels via surfactant-free emulsion photopolymerization. TMC, a quaternized derivative of chitosan, was synthesized through methylation of chitosan, resulting in quaternary and tertiary amine groups as the main substitution products. TMC tertiary amine moiety and riboflavin (RF) acted as a redox photo-initiating system to generate free radicals for the polymerization under light irradiation. The effects of polymerization parameters such as irradiation time, concentrations of TMC and RF were investigated using MBA as crosslinker. Under the optimal condition of 1 % TMC, 4 % HEMA, 0.8 μM RF, 5 % MBA, and 4 h of polymerization time, the cationic PHEMA-TMC nanogel was synthesized with 76 % monomer conversion and an average diameter of about 106 nm. Moreover, the disulfide-crosslinked PHEMA-TMC nanogel was also synthesized using the disulfide dimethacrylate crosslinker, which exhibited a redox-induced degradation and release of encapsulated melatonin, potentially useful as a redox-responsive drug delivery carrier.

Enhancing the Neuroprotection Potential of Edaravone in Transient Global Ischemia Treatment with Glutathione- (GSH-) Conjugated Poly(methacrylic acid) Nanogel as a Promising Carrier for Targeted Brain Drug Delivery

Ischemic stroke is the most common among various stroke types and the second leading cause of death, worldwide. Edaravone (EDV) is one of the cardinal antioxidants that is capable of scavenging reactive oxygen species, especially hydroxyl molecules, and has been already used for ischemic stroke treatment. However, poor water solubility, low stability, and bioavailability in aqueous media are major EDV drawbacks. Thus, to overcome the aforementioned drawbacks, nanogel was exploited as a drug carrier of EDV. Furthermore, decorating the nanogel surface with glutathione as targeting ligands would potentiate the therapeutic efficacy. Nanovehicle characterization was assessed with various analytical techniques. Size (199 nm, hydrodynamic diameter) and zeta potential (-25 mV) of optimum formulation were assessed. The outcome demonstrated a diameter of around 100 nm, sphere shape, and homogenous morphology. Encapsulation efficiency and drug loading were determined to be 99.9% and 37.5%, respectively. In vitro drug release profile depicted a sustained release process. EDV and glutathione presence in one vehicle simultaneously made the possibility of antioxidant effects on the brain in specific doses, which resulted in elevated spatial memory and learning along with cognitive function in Wistar rats. In addition, significantly lower MDA and PCO and higher levels of neural GSH and antioxidant levels were observed, while histopathological improvement was approved. The developed nanogel can be a suited vehicle for drug delivery of EDV to the brain and improve ischemia-induced oxidative stress cell damage.

Innovation in the Development of Synthetic and Natural Ocular Drug Delivery Systems for Eye Diseases Treatment: Focusing on Drug-Loaded Ocular Inserts, Contacts, and Intraocular Lenses

Nowadays, ocular drug delivery still remains a challenge, since the conventional dosage forms used for anterior and posterior ocular disease treatments, such as topical, systemic, and intraocular administration methods, present important limitations mainly related to the anatomical complexity of the eye. In particular, the blood-ocular barrier along with the corneal barrier, ocular surface, and lacrimal fluid secretion reduce the availability of the administered active compounds and their efficacy. These limitations have increased the need to develop safe and effective ocular delivery systems able to sustain the drug release in the interested ocular segment over time. In the last few years, thanks to the innovations in the materials and technologies employed, different ocular drug delivery systems have been developed. Therefore, this review aims to summarize the synthetic and natural drug-loaded ocular inserts, contacts, and intraocular lenses that have been recently developed, emphasizing the characteristics that make them promising for future ocular clinical applications.

Chitosan-Based Hemostatic Hydrogels: The Concept, Mechanism, Application, and Prospects

The design of new hemostatic materials to mitigate uncontrolled bleeding in emergencies is challenging. Chitosan-based hemostatic hydrogels have frequently been used for hemostasis due to their unique biocompatibility, tunable mechanical properties, injectability, and ease of handling. Moreover, chitosan (CS) absorbs red blood cells and activates platelets to promote hemostasis. Benefiting from these desired properties, the hemostatic application of CS hydrogels is attracting ever-increasing research attention. This paper reviews the recent research progress of CS-based hemostatic hydrogels and their advantageous characteristics compared to traditional hemostatic materials. The effects of the hemostatic mechanism, effects of deacetylation degree, relative molecular mass, and chemical modification on the hemostatic performance of CS hydrogels are summarized. Meanwhile, some typical applications of CS hydrogels are introduced to provide references for the preparation of efficient hemostatic hydrogels. Finally, the future perspectives of CS-based hemostatic hydrogels are presented.

Chemical, physical, and biological stimuli-responsive nanogels for biomedical applications (mechanisms, concepts, and advancements): A review

The development of nanotechnology has influenced the advancements in biomedical and pharmaceutical fields. The design and formulation of stimuli-responsive nano-drug delivery systems, also called smart drug delivery systems, have attracted significant research worldwide and have been seen as a breakthrough in nanomedicines. The ability of these nanocarriers to respond to external and internal stimuli, such as pH, temperature, redox, electric and magnetic fields, enzymes, etc., has allowed them to deliver the cargo at targeted sites in a controlled fashion. The targeted drug delivery systems limit the harmful side effects on healthy tissue by toxic drugs and furnish spatial and temporal control drug delivery, improved patient compliance, and treatment efficiency. The polymeric nanogels (hydrogel nanoparticles) with stimuli-responsive characteristics have shown great potential in various biomedical, tissue engineering, and pharmaceutical fields. It is primarily because of their small size, biocompatibility, biodegradability, stimuli-triggered drug deliverability, high payload capacity, and tailored functionality. This comprehensive review deals distinctively with polymeric nanogels, their chemical, physical, and biological stimuli, the concepts of nanogels response to different stimuli, and recent advancements. This document will further improve the current understanding of stimuli-responsive materials and drug delivery systems and assist in exploring advanced potential applications of these intelligent materials.

CuAAC ensembled 1,2,3-triazole linked nanogels for targeted drug delivery: a review

Copper(i) catalyzed alkyne azide cycloaddition (CuAAC), the quintessential example of 'click chemistry', provides an adaptable and adequate platform for the synthesis of nanogels for sustained drug release at targeted sites because of their better biocompatibility. The coupling of drugs, carried out via various synthetic routes including CuAAC, into long-chain polymeric forms like nanogels has exhibited considerable assurance in therapeutic advancements and intracellular drug delivery due to the progression of water solubility, evacuation of precocious drug release, and improved upthrust of the pharmacokinetics of the nanogels, thereby rendering them as better and efficient drug carriers. The inefficiency of drug transmission to the target areas due to the resistance of complex biological barriers in vivo is a major hurdle that impedes the therapeutic translation of nanogels. This review compiles the data of nanogels synthesized specifically via CuAAC 'click' methodology, as scaffolds for targeted drug delivery and their assimilation into nanomedicine. In addition, it elaborates the ability of CuAAC to graft specific moieties and conjugating biomolecules like proteins and growth factors, onto orthogonally functionalized polymer chains with various chemical groups resulting in nanogels that are not only more appealing but also more effective at delivering drugs, thereby enhancing their site-specific target approach and initiating selective therapies.

Recent Advances in the Biomedical Applications of Functionalized Nanogels

Nanomaterials have been extensively used in several applications in the past few decades related to biomedicine and healthcare. Among them, nanogels (NGs) have emerged as an important nanoplatform with the properties of both hydrogels and nanoparticles for the controlled/sustained delivery of chemo drugs, nucleic acids, or other bioactive molecules for therapeutic or diagnostic purposes. In the recent past, significant research efforts have been invested in synthesizing NGs through various synthetic methodologies such as free radical polymerization, reversible addition-fragmentation chain-transfer method (RAFT) and atom transfer radical polymerization (ATRP), as well as emulsion techniques. With further polymeric functionalizations using activated esters, thiol-ene/yne processes, imines/oximes formation, cycloadditions, nucleophilic addition reactions of isocyanates, ring-opening, and multicomponent reactions were used to obtain functionalized NGs for targeted delivery of drug and other compounds. NGs are particularly intriguing for use in the areas of diagnosis, analytics, and biomedicine due to their nanodimensionality, material characteristics, physiological stability, tunable multi-functionality, and biocompatibility. Numerous NGs with a wide range of functionalities and various external/internal stimuli-responsive modalities have been possible with novel synthetic reliable methodologies. Such continuous development of innovative, intelligent materials with novel characteristics is crucial for nanomedicine for next-generation biomedical applications. This paper reviews the synthesis and various functionalization strategies of NGs with a focus on the recent advances in different biomedical applications of these surface modified/functionalized single-/dual-/multi-responsive NGs, with various active targeting moieties, in the fields of cancer theranostics, immunotherapy, antimicrobial/antiviral, antigen presentation for the vaccine, sensing, wound healing, thrombolysis, tissue engineering, and regenerative medicine.

ROS-generating, pH-responsive and highly tunable reduced graphene oxide-embedded microbeads showing intrinsic anticancer properties and multi-drug co-delivery capacity for combination cancer therapy

The development of effective carriers enabling combination cancer therapy is of practical importance due to its potential to enhance the effectiveness of cancer treatment. However, most of the reported carriers are monofunctional in nature. The carriers that can be applied to concomitantly mediate multiple treatment modalities are highly deficient. This study fills this gap by reporting the design and fabrication of ROS-generating carbohydrate-based pH-responsive beads with intrinsic anticancer therapy and multidrug co-delivery capacity for combination cancer therapy. Sodium alginate (SA) microspheres and reduced graphene oxide (rGO)-embedded chitosan (CS) beads are developed via emulsion-templated ionic gelation for a combination therapy involving co-delivery of curcumin (CUR) and 5-fluororacil (5-FU). Drug-encapsulated microbeads are characterized by FTIR, DSC, TGA, XRD, and SEM. 5-FU and CUR-encapsulated microbeads are subjected to in vitro drug release studies at pH 6.8 and 1.2 at 37 °C. Various release kinetic parameters are evaluated. The results show that the Korsmeyer-Peppas model and non-Fickian release kinetics are best suited. The microspheres and microbeads are found to effectively act against MCF7 cells and show intrinsic anticancer capacity. These results indicate the promising performance of our beads in mediating combination drug therapy to improve the effectiveness of cancer treatment.

Noncovalent Enzyme Nanogels via a Photocleavable Linkage

Enzyme nanogels (ENGs) offer a convenient method to protect therapeutic proteins from in vivo stressors. Current methodologies to prepare ENGs rely on either covalent modification of surface residues or the noncovalent assembly of monomers at the protein surface. In this study, we report a new method for the preparation of noncovalent ENGs that utilizes a heterobifunctional, photocleavable monomer as a hybrid approach. Initial covalent modification with this monomer established a polymerizable handle at the protein surface, followed by radical polymerization with poly(ethylene glycol) methacrylate monomer and ethylene glycol dimethacrylate crosslinker in solution. Final photoirradiation cleaved the linkage between the polymer and protein to afford the noncovalent ENGs. The enzyme phenylalanine ammonia lyase (PAL) was utilized as a model protein yielding well-defined nanogels 80 nm in size by dynamic light scattering (DLS) and 76 nm by atomic force microscopy. The stability of PAL after exposure to trypsin or low pH was assessed and was found to be more stable in the noncovalent nanogel compared to PAL alone. This approach may be useful for the stabilization of active enzymes.

Advances in Antitumor Nano-Drug Delivery Systems of 10-Hydroxycamptothecin

10-Hydroxycamptothecin (HCPT) is a natural plant alkaloid from Camptotheca that shows potent antitumor activity by targeting intracellular topoisomerase I. However, factors such as instability of the lactone ring and insolubility in water have limited the clinical application of this drug. In recent years, unprecedented advances in biomedical nanotechnology have facilitated the development of nano drug delivery systems. It has been found that nanomedicine can significantly improve the stability and water solubility of HCPT. NanoMedicines with different diagnostic and therapeutic functions have been developed to significantly improve the anticancer effect of HCPT. In this paper, we collected reports on HCPT nanomedicines against tumors in the past decade. Based on current research advances, we dissected the current status and limitations of HCPT nanomedicines development and looked forward to future research directions.

Fabrication, In Vitro, and In Vivo Assessment of Eucalyptol-Loaded Nanoemulgel as a Novel Paradigm for Wound Healing

Wounds are the most common causes of mortality all over the world. Topical drug delivery systems are more efficient in treating wounds as compared to oral delivery systems because they bypass the disadvantages of the oral route. The aim of the present study was to formulate and evaluate in vitro in vivo nanoemulgels loaded with eucalyptol for wound healing. Nanoemulsions were prepared using the solvent emulsification diffusion method by mixing an aqueous phase and an oil phase, and a nanoemulgel was then fabricated by mixing nanoemulsions with a gelling agent (Carbopol 940) in a 1:1 ratio. The nanoemulgels were evaluated regarding stability, homogeneity, pH, viscosity, Fourier-transform infrared spectroscopy (FTIR), droplet size, zeta potential, polydispersity index (PDI), spreadability, drug content, in vitro drug release, and in vivo study. The optimized formulation, F5, exhibited pH values between 5 and 6, with no significant variations at different temperatures, and acceptable homogeneity and spreadability. F5 had a droplet size of 139 ± 5.8 nm, with a low polydispersity index. FTIR studies showed the compatibility of the drug with the excipients. The drug content of F5 was 94.81%. The percentage of wound contraction of the experimental, standard, and control groups were 100% ± 0.015, 98.170% ± 0.749, and 70.846% ± 0.830, respectively. Statistically, the experimental group showed a significant difference (p < 0.03) from the other two groups. The results suggest that the formulated optimized dosage showed optimum stability, and it can be considered an effective wound healing alternative.

pH and Reduction Dual-Responsive Nanogels as Smart Nanocarriers to Resist Doxorubicin Aggregation

The use of smart nanocarriers that can modulate therapeutic release aided by biological cues can prevent undesirable cytotoxicity caused by the premature release of cytotoxic drugs during nanocarrier circulation. In this report, degradable nanocarriers based on pH/reduction dual-responsive nanogels were synthesized to encapsulate doxorubicin hydrochloride (DOX) and specifically boost the release of DOX in conditions characteristic of the cancer microenvironment. Nanogels containing anionic monomer 2-carboxyethyl acrylate (CEA) and N,N′-bis(acryloyl)cystamine (CBA) as a degradable crosslinker have been successfully synthesized via photoinitiated free radical polymerization. The loading process was conducted after polymerization by taking advantage of the electrostatic interaction between the negatively charged nanogels and the positively charged DOX. In this case, a high drug loading capacity (DLC) of up to 27.89% was achieved. The entrapment of DOX into a nanogel network could prevent DOX from aggregating in biological media at DOX concentrations up to ~160 µg/mL. Anionic nanogels had an average hydrodynamic diameter (d_H) of around 90 nm with a negative zeta (ζ) potential of around −25 mV, making them suitable for targeting cancer tissue via the enhanced permeation effect. DOX-loaded nanogels formed a stable dispersion in different biological media, including serum-enriched cell media. In the presence of glutathione (GSH) and reduced pH, drug release was enhanced, which proves dual responsivity. An in vitro study using the HCT 116 colon cancer cell line demonstrated the enhanced cytotoxic effect of the NG-CBA/DOX-1 nanogel compared to free DOX. Taken together, pH/reduction dual-responsive nanogels show promise as drug delivery systems for anticancer therapy.

Advancements in the studies of novel nanomaterials for inner ear drug delivery

Hearing loss is currently one of the most prevalent sensory disorders worldwide. Because both the blood-labyrinth barrier and the limited blood circulation in the inner ear restrain the effective delivery of most drugs to the inner ear tissues, current treatments for hearing loss are limited to mainly medication, hearing devices and cochlear surgery for therapeutic purposes, whereas treatments lack a noninvasive targeted drug-delivery system. With the continuously rapid development of new nanomaterials, the nanodelivery systems are expected to provide a potentially effective method of clinical treatment for hearing loss. This paper reviews the advantages and disadvantages of the commonly used drug-delivery methods and novel nanomaterials for inner ears as well as advancements in the targeted treatment of hearing loss.

Modern Herbal Nanogels: Formulation, Delivery Methods, and Applications

This study examined the most recent advancements in nanogel production and drug delivery. Phytochemistry is a discipline of chemistry that studies herbal compounds. Herbal substances have aided in the development of innovative remedies for a wide range of illnesses. Several of these compounds are forbidden from being used in medications due to broad medical characteristics and pharmacokinetics. A variety of new technical approaches have been investigated to ameliorate herbal discoveries in the pharmaceutical sector. The article focuses on the historical data for herb-related nanogels that are used to treat a variety of disorders with great patient compliance, delivery rate, and efficacy. Stimulus-responsive nanogels such as temperature responsive and pH-responsive systems are also discussed. Nanogel formulations, which have been hailed as promising targets for drug delivery systems, have the ability to alter the profile of a drug, genotype, protein, peptide, oligosaccharide, or immunogenic substance, as well as its ability to cross biological barriers, biodistribution, and pharmacokinetics, improving efficacy, safety, and patient cooperation.

Development, Characterization, and Evaluation of α-Mangostin-Loaded Polymeric Nanoparticle Gel for Topical Therapy in Skin Cancer

The aim of this study was to prepare and evaluate α-mangostin-loaded polymeric nanoparticle gel (α-MNG-PLGA) formulation to enhance α-mangostin delivery in an epidermal carcinoma. The poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) were developed using the emulsion-diffusion-evaporation technique with a 3-level 3-factor Box-Behnken design. The NPs were characterized and evaluated for particle size distribution, zeta potential (mV), drug release, and skin permeation. The formulated PLGA NPs were converted into a preformed carbopol gel base and were further evaluated for texture analysis, the cytotoxic effect of PLGA NPs against B16-F10 melanoma cells, and in vitro radical scavenging activity. The nanoscale particles were spherical, consistent, and average in size (168.06 ± 17.02 nm), with an entrapment efficiency (EE) of 84.26 ± 8.23% and a zeta potential of -25.3 ± 7.1 mV. Their drug release percentages in phosphate-buffered solution (PBS) at pH 7.4 and pH 6.5 were 87.07 ± 6.95% and 89.50 ± 9.50%, respectively. The release of α-MNG from NPs in vitro demonstrated that the biphasic release system, namely, immediate release in the initial phase, was accompanied by sustained drug release. The texture study of the developed α-MNG-PLGA NPs gel revealed its characteristics, including viscosity, hardness, consistency, and cohesiveness. The drug flux from α-MNG-PLGA NPs gel and α-MNG gel was 79.32 ± 7.91 and 16.88 ± 7.18 µg/cm2/h in 24 h, respectively. The confocal study showed that α-MNG-PLGA NPs penetrated up to 230.02 µm deep into the skin layer compared to 15.21 µm by dye solution. MTT assay and radical scavenging potential indicated that α-MNG-PLGA NPs gel had a significant cytotoxic effect and antioxidant effect compared to α-MNG gel (p < 0.05). Thus, using the developed α-MNG-PLGA in treating skin cancer could be a promising approach.

Current Advances in Lipid and Polymeric Antimicrobial Peptide Delivery Systems and Coatings for the Prevention and Treatment of Bacterial Infections

Bacterial infections constitute a threat to public health as antibiotics are becoming less effective due to the emergence of antimicrobial resistant strains and biofilm and persister formation. Antimicrobial peptides (AMPs) are considered excellent alternatives to antibiotics; however, they suffer from limitations related to their peptidic nature and possible toxicity. The present review critically evaluates the chemical characteristics and antibacterial effects of lipid and polymeric AMP delivery systems and coatings that offer the promise of enhancing the efficacy of AMPs, reducing their limitations and prolonging their half-life. Unfortunately, the antibacterial activities of these systems and coatings have mainly been evaluated in vitro against planktonic bacteria in less biologically relevant conditions, with only some studies focusing on the antibiofilm activities of the formulated AMPs and on the antibacterial effects in animal models. Further improvements of lipid and polymeric AMP delivery systems and coatings may involve the functionalization of these systems to better target the infections and an analysis of the antibacterial activities in biologically relevant environments. Based on the available data we proposed which polymeric AMP delivery system or coatings could be profitable for the treatment of the different hard-to-treat infections, such as bloodstream infections and catheter- or implant-related infections.