An Antifouling Hydrogel Containing Silver Nanoparticles for Modulating the Therapeutic Immune Response in Chronic Wound Healing

Hybrid Nanoparticle-Hydrogel Systems for Drug Delivery Depots and Other Biomedical Applications

Hydrogel-based depots typically tend to remain where injected and have excellent biocompatibility but are relatively poor at controlling drug release. Nanoparticles (NPs) typically have the opposite properties. The smaller the NPs are, the more likely they are to leave the site of injection. Their biocompatibility is variable depending on the material but can be poor. However, NPs can be good at controlling drug release. In these and other properties, combining NPs and hydrogels can leverage their advantages and negate their disadvantages. This review highlights the rationale for hybrid NP-hydrogel systems in drug delivery, the basic methods of producing them, and examples where combining the two systems addressed specific problems.

Molecular immunological mechanisms of impaired wound healing in diabetic foot ulcers (DFU), current therapeutic strategies and future directions

Diabetic foot ulcer (DFU) is a foremost cause of amputation in diabetic patients. Consequences of DFU include infections, decline in limb function, hospitalization, amputation, and in severe cases, death. Immune cells including macrophages, regulatory T cells, fibroblasts and other damage repair cells work in sync for effective healing and in establishment of a healthy skin barrier post-injury. Immune dysregulation during the healing of wounds can result in wound chronicity. Hyperglycemic conditions in diabetic patients influence the pathophysiology of wounds by disrupting the immune system as well as promoting neuropathy and ischemic conditions, making them difficult to heal. Chronic wound microenvironment is characterized by increased expression of matrix metalloproteinases, reactive oxygen species as well as pro-inflammatory cytokines, resulting in persistent inflammation and delayed healing. Novel treatment modalities including growth factor therapies, nano formulations, microRNA based treatments and skin grafting approaches have significantly augmented treatment efficiency, demonstrating creditable efficacy in clinical practices. Advancements in local treatments as well as invasive methodologies, for instance formulated wound dressings, stem cell applications and immunomodulatory therapies have been successful in targeting the complex pathophysiology of chronic wounds. This review focuses on elucidating the intricacies of emerging physical and non-physical therapeutic interventions, delving into the realm of advanced wound care and comprehensively summarizing efficacy of evidence-based therapies for DFU currently available.

Metal Nanoparticles: Advanced and Promising Technology in Diabetic Wound Therapy

Diabetic wounds pose a significant challenge to public health, primarily due to insufficient blood vessel supply, bacterial infection, excessive oxidative stress, and impaired antioxidant defenses. The aforementioned condition not only places a significant physical burden on patients' prognosis, but also amplifies the economic strain on the medical system in treating diabetic wounds. Currently, the effectiveness of available treatments for diabetic wounds is limited. However, there is hope in the potential of metal nanoparticles (MNPs) to address these issues. MNPs exhibit excellent anti-inflammatory, antioxidant, antibacterial and pro-angiogenic properties, making them a promising solution for diabetic wounds. In addition, MNPs stimulate the expression of proteins that promote wound healing and serve as drug delivery systems for small-molecule drugs. By combining MNPs with other biomaterials such as hydrogels and chitosan, novel dressings can be developed and revolutionize the treatment of diabetic wounds. The present article provides a comprehensive overview of the research progress on the utilization of MNPs for treating diabetic wounds. Building upon this foundation, we summarize the underlying mechanisms involved in diabetic wound healing and discuss the potential application of MNPs as biomaterials for drug delivery. Furthermore, we provide an extensive analysis and discussion on the clinical implementation of dressings, while also highlighting future prospects for utilizing MNPs in diabetic wound management. In conclusion, MNPs represent a promising strategy for the treatment of diabetic wound healing. Future directions include combining other biological nanomaterials to synthesize new biological dressings or utilizing the other physicochemical properties of MNPs to promote wound healing. Synthetic biomaterials that contain MNPs not only play a role in all stages of diabetic wound healing, but also provide a stable physiological environment for the wound-healing process.

Progress in injectable hydrogels for the treatment of incompressible bleeding: an update

Uncontrollable haemorrhage from deep, noncompressible wounds remains a persistent and intractable challenge, accounting for a very high proportion of deaths in both war and disaster situations. Recently, injectable hydrogels have been increasingly studied as potential haemostatic materials, highlighting their enormous potential for the management of noncompressible haemorrhages. In this review, we summarize haemostatic mechanisms, commonly used clinical haemostatic methods, and the research progress on injectable haemostatic hydrogels. We emphasize the current status of injectable hydrogels as haemostatic materials, including their physical and chemical properties, design strategy, haemostatic mechanisms, and application in various types of wounds. We discuss the advantages and disadvantages of injectable hydrogels as haemostatic materials, as well as the opportunities and challenges involved. Finally, we propose cutting-edge research avenues to address these challenges and opportunities, including the combination of injectable hydrogels with advanced materials and innovative strategies to increase their biocompatibility and tune their degradation profile. Surface modifications for promoting cell adhesion and proliferation, as well as the delivery of growth factors or other biologics for optimal wound healing, are also suggested. We believe that this paper will inform researchers about the current status of the use of injectable haemostatic hydrogels for noncompressible haemorrhage and spark new ideas for those striving to propel this field forward.

Self-healing and durable antifouling zwitterionic hydrogels based on functionalized liquid metal microgels

Hydrogels are a promising new class of antifouling materials. But their utility is constrained by low mechanical strength and unsatisfactory antifouling performance over the long term. Herein, we successfully prepared zwitterionic polymer PEIS cross-linked gallium-based liquid metal microgels-based (PEIS-Gel@PMPC-GLM) hydrogels via UV-curing and amidation reaction. The as-prepared hydrogels showed preferable mechanical properties and superior hydrophilicity to the original hydrogels. The PEIS-Gel@PMPC-GLM hydrogels could prevent the adhesion of more than 90 % of microalgae and nearly 100 % of bacteria in a short-term antifouling test. PEIS-Gel@PMPC-GLM hydrogels also performed exceptionally well in the high concentration antibacterial test and the long-term antifouling test (remove more than 90 % bacteria and 80 % microalgae). In addition to releasing a high concentration of gallium ions, as shown by the ICP-OES test, PEIS-Gel@PMPC-GLM hydrogels also exhibitedexcellent lubrication performance, as demonstrated by the friction test (coefficient of friction as low as 0.023). Therefore, the antifouling effect of gallium ions combined with the strong hydration ability of the surfaces endowed the hydrogels remarkable antibacterial and antifouling properties. As a result of the exposed gallium atoms inducing further crosslinking of residual vinyl monomer in hydrogels, PEIS-Gel@PMPC-GLM hydrogels revealed certain self-healing performance.

Nano-CeO2-Loaded Polyzwitterionic Double-Network High-Strength Hydrogel for Highly Enhanced Synergistic Marine Antifouling

Although many antibiofouling materials have been developed based on either bacterial-killing or antiadhesion effects, the integration of both the effects in one material remains challenging for achieving highly enhanced synergistic antibiofouling. In this study, we have explored a nano-CeO2-loaded double-network hydrogel by introducing CeO2 nanorods into a polyzwitterionic hydrogel via a simple one-pot method for achieving highly efficient antifouling. First, the CeO2 nanorods dispersed in the hydrogel, as an outstanding nanozyme, have highly efficient bacterial-killing performance. Second, the superhydrophilic polyzwitterionic hydrogel provides a dense hydrated layer on the surface and subsequently excellent broad-spectrum antiadhesion behavior. Most importantly, the bacterial killing and antiadhesion of this hydrogel can work synergistically to largely improve the marine-antifouling performance. Moreover, the double-network structure of this hydrogel, including the covalently cross-linked polyzwitterion hard network and the physically cross-linked poly(vinyl alcohol) soft network, can provide greatly improved mechanical properties (2.44 MPa of tensile strength reaches and 21.87 MPa of compressive strength). As a result, among the existing marine-antifouling hydrogels, the CeO2-loaded polyzwitterionic double-network hydrogel can achieve outstanding antifouling performance, which can sustain for over 6 months in a real marine environment. This work provides a promising marine-antifouling hydrogel, which will also inspire antifouling research of a new strategy and materials.

Unraveling the New Perspectives on Antimicrobial Hydrogels: State-of-the-Art and Translational Applications

The growing impact of infections and the rapid emergence of antibiotic resistance represent a public health concern worldwide. The exponential development in the field of biomaterials and its multiple applications can offer a solution to the problems that derive from these situations. In this sense, antimicrobial hydrogels represent a promising opportunity with multiple translational expectations in the medical management of infectious diseases due to their unique physicochemical and biological properties as well as for drug delivery in specific areas. Hydrogels are three-dimensional cross-linked networks of hydrophilic polymers that can absorb and retain large amounts of water or biological fluids. Moreover, antimicrobial hydrogels (AMH) present good biocompatibility, low toxicity, availability, viscoelasticity, biodegradability, and antimicrobial properties. In the present review, we collect and discuss the most promising strategies in the development of AMH, which are divided into hydrogels with inherent antimicrobial activity and antimicrobial agent-loaded hydrogels based on their composition. Then, we present an overview of the main translational applications: wound healing, tissue engineering and regeneration, drug delivery systems, contact lenses, 3D printing, biosensing, and water purification.

A Review of Metal Nanoparticles Embedded in Hydrogel Scaffolds for Wound Healing In Vivo

An evolving field, nanotechnology has made its mark in the fields of nanoscience, nanoparticles, nanomaterials, and nanomedicine. Specifically, metal nanoparticles have garnered attention for their diverse use and applicability to dressings for wound healing due to their antimicrobial properties. Given their convenient integration into wound dressings, there has been increasing focus dedicated to investigating the physical, mechanical, and biological characteristics of these nanoparticles as well as their incorporation into biocomposite materials, such as hydrogel scaffolds for use in lieu of antibiotics as well as to accelerate and ameliorate healing. Though rigorously tested and applied in both medical and non-medical applications, further investigations have not been carried out to bring metal nanoparticle-hydrogel composites into clinical practice. In this review, we provide an up-to-date, comprehensive review of advancements in the field, with emphasis on implications on wound healing in in vivo experiments.

Wound healing strategies based on nanoparticles incorporated in hydrogel wound patches

The intricate, tightly controlled mechanism of wound healing that is a vital physiological mechanism is essential to maintaining the skin's natural barrier function. Numerous studies have focused on wound healing as it is a massive burden on the healthcare system. Wound repair is a complicated process with various cell types and microenvironment conditions. In wound healing studies, novel therapeutic approaches have been proposed to deliver an effective treatment. Nanoparticle-based materials are preferred due to their antibacterial activity, biocompatibility, and increased mechanical strength in wound healing. They can be divided into six main groups: metal NPs, ceramic NPs, polymer NPs, self-assembled NPs, composite NPs, and nanoparticle-loaded hydrogels. Each group shows several advantages and disadvantages, and which material will be used depends on the type, depth, and area of the wound. Better wound care/healing techniques are now possible, thanks to the development of wound healing strategies based on these materials, which mimic the extracellular matrix (ECM) microenvironment of the wound. Bearing this in mind, here we reviewed current studies on which NPs have been used in wound healing and how this strategy has become a key biotechnological procedure to treat skin infections and wounds.

Poisson-Nernst-Planck framework for modelling ionic strain and temperature sensors

Ionically conductive hydrogels are gaining traction as sensing and structural materials for use bioelectronic devices. Hydrogels that feature large mechanical compliances and tractable ionic conductivities are compelling materials that can sense physiological states and potentially modulate the stimulation of excitable tissue because of the congruence in electro-mechanical properties across the tissue-material interface. However, interfacing ionic hydrogels with conventional DC voltage-based circuits poses several technical challenges including electrode delamination, electrochemical reaction, and drifting contact impedance. Utilizing alternating voltages to probe ion-relaxation dynamics has been shown to be a viable alternative for strain and temperature sensing. In this work, we present a Poisson-Nernst-Planck theoretical framework to model ion transport under alternating fields within conductors subject to varying strains and temperatures. Using simulated impedance spectra, we develop key insights about the relationship between frequency of the applied voltage perturbation and sensitivity. Lastly, we perform preliminary experimental characterization to demonstrate the applicability of the proposed theory. We believe this work provides a useful perspective that is applicable to the design of a variety of ionic hydrogel-based sensors for biomedical and soft robotic applications.

Therapeutic applications of nanobiotechnology

Nanobiotechnology, as a novel and more specialized branch of science, has provided a number of nanostructures such as nanoparticles, by utilizing the methods, techniques, and protocols of other branches of science. Due to the unique features and physiobiological characteristics, these nanostructures or nanocarriers have provided vast methods and therapeutic techniques, against microbial infections and cancers and for tissue regeneration, tissue engineering, and immunotherapies, and for gene therapies, through drug delivery systems. However, reduced carrying capacity, abrupt and non-targeted delivery, and solubility of therapeutic agents, can affect the therapeutic applications of these biotechnological products. In this article, we explored and discussed the prominent nanobiotechnological methods and products such as nanocarriers, highlighted the features and challenges associated with these products, and attempted to conclude if available nanostructures offer any scope of improvement or enhancement. We aimed to identify and emphasize the nanobiotechnological methods and products, with greater prospect and capacity for therapeutic improvements and enhancements. We found that novel nanocarriers and nanostructures, such as nanocomposites, micelles, hydrogels, microneedles, and artificial cells, can address the associated challenges and inherited drawbacks, with help of conjugations, sustained and stimuli-responsive release, ligand binding, and targeted delivery. We recommend that nanobiotechnology, despite having few challenges and drawbacks, offers immense opportunities that can be harnessed in delivering quality therapeutics with precision and prediction. We also recommend that, by exploring the branched domains more rigorously, bottlenecks and obstacles can also be addressed and resolved in return.

Design and fabrication of magnetic Fe3O4-QSM nanoparticles loaded with ciprofloxacin as a potential antibacterial agent

In this investigation, we have synthesized magnetite nanoparticles (Fe₃O₄ NPs) coated with quince seed mucilage (QSM) as a natural, biocompatible, and biodegradable component and loaded them with ciprofloxacin (CIP) to act as an antibacterial agent. The structural, magnetic, physicochemical, colloidal, and antibacterial properties of the samples were tested using various characterization tools such as XRD, TEM, FE-SEM, VSM, FT-IR, UV-Vis, DLS, BET, and disk diffusion for testing the antibacterial properties. XRD and VSM results confirmed the fabrication of a highly pure cubic spinel phase for Fe₃O₄. The results of FE-SEM and TEM analyses indicate a spherical morphology of the magnetite NPs with a mean diameter of about 13 nm, and the results of DLS show a hydrodynamic diameter of 81.9 to 119.2 nm. The zeta potential value for the magnetic Fe₃O₄ NPs was as high as -55.2 mV, indicating suitable colloidal stability of the NPs for biological applications. The VSM results indicate a high saturation magnetization of the samples as well as a small coercivity and Remanence of the samples, which indicate the superparamagnetic property of the NPs. It was also indicated that the amount of drug adsorbed on the magnetic nanoparticles at different pH values (5.5 to 6.5) is about 85 %. It was likewise detected that the synthesized Fe₃O₄@QSM-CIP NPs possess antibacterial activity against standard strains of both Gram positive and Gram-negative bacteria (minimum inhibitory concentration = 100 ppm). The overall findings imply that the proposed magnetic NPs with antibacterial activity are promising for biomedical applications.

Therapeutic Efficacy of Polymeric Biomaterials in Treating Diabetic Wounds-An Upcoming Wound Healing Technology

Diabetic wounds are one of the serious, non-healing, chronic health issues faced by individuals suffering from diabetic mellitus. The distinct phases of wound healing are either prolonged or obstructed, resulting in the improper healing of diabetic wounds. These injuries require persistent wound care and appropriate treatment to prevent deleterious effects such as lower limb amputation. Although there are several treatment strategies, diabetic wounds continue to be a major threat for healthcare professionals and patients. The different types of diabetic wound dressings that are currently used differ in their properties of absorbing wound exudates and may also cause maceration to surrounding tissues. Current research is focused on developing novel wound dressings incorporated with biological agents that aid in a faster rate of wound closure. An ideal wound dressing material must absorb wound exudates, aid in the appropriate exchange of gas, and protect from microbial infections. It must support the synthesis of biochemical mediators such as cytokines, and growth factors that are crucial for faster healing of wounds. This review highlights the recent advances in polymeric biomaterial-based wound dressings, novel therapeutic regimes, and their efficacy in treating diabetic wounds. The role of polymeric wound dressings loaded with bioactive compounds, and their in vitro and in vivo performance in diabetic wound treatment are also reviewed.

Silver Nanoparticles Phytofabricated through Azadirachta indica: Anticancer, Apoptotic, and Wound-Healing Properties

Silver nanoparticles (AgNPs) have unlocked numerous novel disciplines in nanobiotechnological protocols due to their larger surface area-to-volume ratios, which are attributed to the marked reactivity of nanosilver, and due to their extremely small size, which enables AgNPs to enter cells, interact with organelles, and yield distinct biological effects. AgNPs are capable of bypassing immune cells, staying in the system for longer periods and with a higher distribution, reaching target tissues at higher concentrations, avoiding diffusion to adjacent tissues, releasing therapeutic agents or drugs for specific stimuli to achieve a longer duration at a specific rate, and yielding desired effects. The phytofabrication of AgNPs is a cost-effective, one-step, environmentally friendly, and easy method that harnesses sustainable resources and naturally available components of plant extracts (PEs). In addition, it processes various catalytic activities for the degradation of various organic pollutants. For the phytofabrication of AgNPs, plant products can be used in a multifunctional manner as a reducing agent, a stabilizing agent, and a functionalizing agent. In addition, they can be used to curtail the requirements for any additional stabilizing agents and to help the reaction stages subside. Azadirachta indica, a very common and prominent medicinal plant grown throughout the Indian subcontinent, possesses free radical scavenging and other pharmaceutical properties via the regulation of proinflammatory enzymes, such as COX and TOX. It also demonstrates anticancer activities through cell-signaling pathways, modulating tumor-suppressing genes such as p53 and pTEN, transcriptional factors, angiogenesis, and apoptosis via bcl2 and bax. In addition, it possesses antibacterial activities. Phytofabricated AgNPs have been applied in the areas of drug delivery, bioimaging, biosensing, cancer treatment, cosmetics, and cell biology. Such pharmaceutical and biological activities of phytofabricated AgNPs are attributed to more than 300 phytochemicals found in Azadirachta indica, and are especially abundant in flavonoids, polyphenols, diterpenoids, triterpenoids, limonoids, tannins, coumarin, nimbolide, azadirachtin, azadirone, azadiradione, and gedunin. Parts of Azadirachta indica, including the leaves in various forms, have been used for wound healing or as a repellent. This study was aimed at examining previously biosynthesized (from Azadirachta indica) AgNPs for anticancer, wound-healing, and antimicrobial actions (through MTT reduction assay, scratch assay, and microbroth dilution methods, respectively). Additionally, apoptosis in cancer cells and the antibiofilm capabilities of AgNPs were examined through caspase-3 expression, dentine block, and crystal violet methods. We found that biogenic silver nanoparticles are capable of inducing cytotoxicity in HCT-116 colon carcinoma cells (IC50 of 744.23 µg/mL, R2: 0.94), but are ineffective against MCF-7 breast cancer cells (IC50 >> 1000 µg/mL, R2: 0.86). AgNPs (IC50 value) induced a significant increase in caspase-3 expression (a 1.5-fold increase) in HCT-116, as compared with control cells. FITC-MFI was 1936 in HCT-116-treated cells, as compared to being 4551 in cisplatin and 1297 in untreated cells. AgNPs (6.26 µg/mL and 62.5 µg/mL) induced the cellular migration (40.2% and 33.23%, respectively) of V79 Chinese hamster lung fibroblasts; however, the improvement in wound healing was not significant as it was for the controls. AgNPs (MIC of 10 µg/mL) were very effective against MDR Enterococcus faecalis in the planktonic mode as well as in the biofilm mode. AgNPs (10 µg/mL and 320 µg/mL) reduced the E. faecalis biofilm by >50% and >80%, respectively. Natural products, such as Syzygium aromaticum (clove) oil (MIC of 312.5 µg/mL) and eugenol (MIC of 625 µg/mL), showed significant antimicrobial effects against A. indica. Our findings indicate that A. indica-functionalized AgNPs are effective against cancer cells and can induce apoptosis in HCT-116 colon carcinoma cells; however, the anticancer properties of AgNPs can also be upgraded through active targeting (functionalized with enzymes, antibiotics, photosensitizers, or antibodies) in immunotherapy, photothermal therapy, and photodynamic therapy. Our findings also suggest that functionalized AgNPs could be pivotal in the development of a novel, non-cytotoxic, biocompatible therapeutic agent for infected chronic wounds, ulcers, and skin lesions involving MDR pathogens via their incorporation into scaffolds, composites, patches, microgels, or formulations for microneedles, dressings, bandages, gels, or other drug-delivery systems.

Polysaccharide-based hydrogels: New insights and futuristic prospects in wound healing

Polysaccharides elicit enormous and promising applications due to their extensive obtainability, innocuousness, and biodegradability. Various outstanding features of polysaccharides can be employed to fabricate biomimetic and multifunctional hydrogels as efficient wound dressings. These hydrogels mimic the natural extracellular matrix and also boost the proliferation of cells. Owing to distinctive architectures and abundance of functional groups, polysaccharide-derived hydrogels have exceptional physicochemical properties and unique therapeutic interventions. Hydrogels designed using polysaccharides can effectively safeguard wounds from bacterial attack. This review includes wound physiology and emphasises on numerous polysaccharide-based hydrogels for wound repair applications. Polysaccharide hydrogels for different wound types and diverse therapeutic agents loaded in hydrogels for wound repair with recent patents are portrayed in the current manuscript, debating the potential of fascinating hydrogels for effective wound healing. More research is required to engineer multifaceted advanced polysaccharide hydrogels with tuneable and adjustable properties to attain huge potential in wound healing.

Beneficial Effect of Wound Dressings Containing Silver and Silver Nanoparticles in Wound Healing-From Experimental Studies to Clinical Practice

Impaired wound healing affects hundreds of million people around the world; therefore, chronic wounds are a major problem not only for the patient, but also for already overloaded healthcare systems. Chronic wounds are always very susceptible to infections. Billions of dollars are spent to discover new antibiotics as quickly as possible; however, bacterial resistance against antibiotics is rising even faster. For this reason, a complete shift of the antibacterial treatment paradigm is necessary. The development of technology has allowed us to rediscover well-known agents presenting antimicrobial properties with a better outcome. In this context, silver nanoparticles are a promising candidate for use in such therapy. Silver has many useful properties that can be used in the treatment of chronic wounds, such as anti-bacterial, anti-inflammatory, and anti-oxidative properties. In the form of nanoparticles, silver agents can work even more effectively and can be more easily incorporated into various dressings. Silver-based dressings are already commercially available; however, innovative combinations are still being discovered and very promising results have been described. In this review article, the authors focused on describing experimental and clinical studies exploring dressings containing either silver or silver nanoparticles, the results of which have been published in recent years.

Nanomaterials-Functionalized Hydrogels for the Treatment of Cutaneous Wounds

Hydrogels have been utilized extensively in the field of cutaneous wound treatment. The introduction of nanomaterials (NMs), which are a big category of materials with diverse functionalities, can endow the hydrogels with additional and multiple functions to meet the demand for a comprehensive performance in wound dressings. Therefore, NMs-functionalized hydrogels (NMFHs) as wound dressings have drawn intensive attention recently. Herein, an overview of reports about NMFHs for the treatment of cutaneous wounds in the past five years is provided. Firstly, fabrication strategies, which are mainly divided into physical embedding and chemical synthesis of the NMFHs, are summarized and illustrated. Then, functions of the NMFHs brought by the NMs are reviewed, including hemostasis, antimicrobial activity, conductivity, regulation of reactive oxygen species (ROS) level, and stimulus responsiveness (pH responsiveness, photo-responsiveness, and magnetic responsiveness). Finally, current challenges and future perspectives in this field are discussed with the hope of inspiring additional ideas.

Recent Advancement of Functional Hydrogels toward Diabetic Wound Management

Wound healing is a dynamic, orchestrated process comprising partially overlapping phases of hemostasis, inflammation, proliferation, and remodeling. This programmed process, dysregulated in diabetic individuals, results in chronic diabetic wounds. The normal process of healing halts at the inflammatory stage, and this prolonged inflammatory phase is characteristic of diabetic wounds. There are a few U.S. Food & Drug Administration approved skin substitutes; dermal matrixes are commercially available to manage diabetic wounds. However, expensiveness and nonresponsiveness in a few instances are the major limitations of such modalities. To address the issues, several treatment strategies have been exploited to treat chronic wounds; among them hydrogel-based systems showed promise due to favorable properties such as excellent absorption capabilities, porous structure, tunable mechanical strength, and biocompatibility. In the past two decades, hydrogels have become one of the most acceptable systems in the field of wound dressing material, offering single functionality to multifunctionality. This review focuses on the advancement of functional hydrogels explored for diabetic wound management. The process of diabetic wound healing is discussed in the light of the normal healing process, and the role of macrophages in the process is explained. This review also discusses the different approaches to treat diabetic wounds using functional hydrogels, along with their future opportunities.

A Comprehensive Review of the Application of Nanoparticles in Diabetic Wound Healing: Therapeutic Potential and Future Perspectives

Diabetic wounds are one of the most challenging public health issues of the 21st century due to their inadequate vascular supply, bacterial infections, high levels of oxidative stress, and abnormalities in antioxidant defenses, whereas there is no effective treatment for diabetic wounds. Due to the distinct properties of nanoparticles, such as their small particle size, elevated cellular uptake, low cytotoxicity, antibacterial activity, good biocompatibility, and biodegradability. The application of nanoparticles has been widely used in the treatment of diabetic wound healing due to their superior anti-inflammatory, antibacterial, and antioxidant activities. These nanoparticles can also be loaded with various agents, such as organic molecules (eg, exosomes, small molecule compounds, etc.), inorganic molecules (metals, nonmetals, etc.), or complexed with various biomaterials, such as smart hydrogels (HG), chitosan (CS), and hyaluronic acid (HA), to augment their therapeutic potential in diabetic wounds. This paper reviews the therapeutic potential and future perspective of nanoparticles in the treatment of diabetic wounds. Together, nanoparticles represent a promising strategy in the treatment of diabetic wound healing. The future direction may be to develop novel nanoparticles with multiple effects that not only act in wound healing at all stages of diabetes but also provide a stable physiological environment throughout the wound-healing process.

Effect of composite biodegradable biomaterials on wound healing in diabetes

The repair of diabetic wounds has always been a job that doctors could not tackle quickly in plastic surgery. To solve this problem, it has become an important direction to use biocompatible biodegradable biomaterials as scaffolds or dressing loaded with a variety of active substances or cells, to construct a wound repair system integrating materials, cells, and growth factors. In terms of wound healing, composite biodegradable biomaterials show strong biocompatibility and the ability to promote wound healing. This review describes the multifaceted integration of biomaterials with drugs, stem cells, and active agents. In wounds, stem cells and their secreted exosomes regulate immune responses and inflammation. They promote angiogenesis, accelerate skin cell proliferation and re-epithelialization, and regulate collagen remodeling that inhibits scar hyperplasia. In the process of continuous combination with new materials, a series of materials that can be well matched with active ingredients such as cells or drugs are derived for precise delivery and controlled release of drugs. The ultimate goal of material development is clinical transformation. At present, the types of materials for clinical application are still relatively single, and the bottleneck is that the functions of emerging materials have not yet reached a stable and effective degree. The development of biomaterials that can be further translated into clinical practice will become the focus of research.

Immunomodulating Hydrogels as Stealth Platform for Drug Delivery Applications

Non-targeted persistent immune activation or suppression by different drug delivery platforms can cause adverse and chronic physiological effects including cancer and arthritis. Therefore, non-toxic materials that do not trigger an immunogenic response during delivery are crucial for safe and effective in vivo treatment. Hydrogels are excellent candidates that can be engineered to control immune responses by modulating biomolecule release/adsorption, improving regeneration of lymphoid tissues, and enhancing function during antigen presentation. This review discusses the aspects of hydrogel-based systems used as drug delivery platforms for various diseases. A detailed investigation on different immunomodulation strategies for various delivery options and deliberate upon the outlook of such drug delivery platforms are conducted.

Recent advances of the nanocomposite hydrogel as a local drug delivery for diabetic ulcers

Diabetic ulcer is a serious complication of diabetes. Compared with that of healthy people, the skin of patients with a diabetic ulcer is more easily damaged and difficult to heal. Without early intervention, the disease will become increasingly serious, often leading to amputation or even death. Most current treatment methods cannot achieve a good wound healing effect. Numerous studies have shown that a nanocomposite hydrogel serves as an ideal drug delivery method to promote the healing of a diabetic ulcer because of its better drug loading capacity and stability. Nanocomposite hydrogels can be loaded with one or more drugs for application to chronic ulcer wounds to promote rapid wound healing. Therefore, this paper reviews the latest progress of delivery systems based on nanocomposite hydrogels in promoting diabetic ulcer healing. Through a review of the recent literature, we put forward the shortcomings and improvement strategies of nanocomposite hydrogels in the treatment of diabetic ulcers.

Hydrogel Dressing Containing Basic Fibroblast Growth Factor Accelerating Chronic Wound Healing in Aged Mouse Model

Due to the decreasing self-repairing ability, elder people are easier to form chronic wounds and suffer from slow and difficult wound healing. It is desirable to develop a novel wound dressing that can accelerate chronic wound healing in elderly subjects to decrease the pain of patients and save medical resources. In this work, Heparin and basic fibroblast growth factor(bFGF) were dissolved in the mixing solution of 4-arm acrylated polyethylene glycol and dithiothreitol to form hydrogel dressing in vitro at room temperature without any catalysts, which is convenient and easy to handle in clinic application. In vitro re-lease test shows the bFGF could be continuously released for at least 7 days, whereas the dressing surface integrity maintained for 3 days degradation in PBS solution. Three groups of treatments including bFGF-Gel, bFGF-Sol and control without any treatment were applied on the full-thickness wound on the 22 months old mice back. The wound closure rate and histological and immunohistochemical staining all illustrated that bFGF-Gel displayed a better wound healing effect than the other two groups. Thus, as-prepared hydrogel dressing seems supe-rior to current clinical treatment and more effective in elderly subjects, which shows promising potential to be applied in the clinic.

Synthesis and Biological Characterization of Phyto-Fabricated Silver Nanoparticles from Azadirachta indica

Nanoparticles (NPs) have garnered a lot of interest in sectors like medicine, cosmetics, food, and pharmaceuticals for antibacterial catalytic properties, reduced toxicity, and easy production. Biological synthesis of silver nanoparticle (AgNPs) is considered as green, eco-friendly, and cost-effective approach; therefore, Azadirachta indica extracts were utilized for a dual role of fabrication and functionalization of AgNPs. Optical and physical characterizations were achieved for confirming the biosynthesized AgNPs. SEM images detected quasi-spherical AgNPs of 44.04 to 66.50 nm. Some of potent phytochemicals like flavonoids and proteins from Azadirachta indica formed a strong coating or capping on the AgNPs without affecting their secondary structure by interacting with Ag+ and NPs for the formation of AgNPs. AgNPs exhibited strong antibacterial activity (MIC 10 μg/ml) against multidrug-resistant bacteria Enterococcus faecalis; at different concentrations, no IC50 values were recorded for AgNPs as well as Azadirachta indica signifying low cytotoxicity in the exposed concentration range. The DNA degradation activity of AgNPs through the TUNEL assay revealed no significant increase in the overall FITC mean fluorescence intensity as well as a DNA fragmentation index with 5.45% DNA damage (10 μg/ml AgNPs). Drug uptake of AgNPs was also investigated through a permeability assay via Caco-2 cell lines at test concentrations where apparent permeability was detected as moderate.

Role of ferroptosis-related genes in coronary atherosclerosis and identification of key genes: integration of bioinformatics analysis and experimental validation

Background

Coronary atherosclerosis (CA) is the most common type of atherosclerosis. However, the inherent pathogenesis and mechanisms of CA are unclear, and the relationship with ferroptosis-related genes (FRGs) has not been reported. The purpose of this study was to use bioinformatics techniques to evaluate potential therapeutic targets for CA.Please provide the given name for author “Dingshun”.Please provide the given name for author “Dingshun”.

Methods

First, the GSE132651 dataset was acquired from the Gene Expression Omnibus database. Gene Ontology enrichment analysis, Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and Protein–Protein interaction network were successively conducted. Next, overlapping genes between hub genes and CA genes were found. FRGs were found when comparing the CA group with the normal group. The correlation between overlapping genes and FRGs was further analyzed. At last, we performed Elisa to validate the expression of these genes in human blood specimens. Mice aortic tissues were used for western blot to detect the expression of proteins.

Results

Based on the GSE132651 dataset, 102 differentially expressed genes were identified. Five overlapping genes between hub genes and CA genes were found (CCNA2, RRM2, PBK, PCNA, CDK1). TFRC and GPX4 were found to be FRGs. TFRC was positively correlated with CCNA2, PBK, PCNA, CDK1, RRM2, with CDK1 being the strongest correlation. GPX4 was negatively correlated with these genes, among which CCNA2 was the strongest correlation. The ELISA results showed that CCNA2, CDK1, and TFRC expression were markedly increased in serum of the CA samples compared with controls, while GPX4 expression was markedly decreased in the CA samples. The western blot results show that GPX4 expression was lower in the model group, TFRC, CDK1, and CCNA2 protein expression were high in the model group.

Conclusions

Ferroptosis-related genes GPX4 and TFRC were closely correlated with the identified overlapping genes CCNA2 and CDK1, which may serve as targeted therapies for the treatment of CA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02747-x.

Nanoparticle Effects on Stress Response Pathways and Nanoparticle-Protein Interactions

Nanoparticles (NPs) are increasingly used in a wide variety of applications and products; however, NPs may affect stress response pathways and interact with proteins in biological systems. This review article will provide an overview of the beneficial and detrimental effects of NPs on stress response pathways with a focus on NP-protein interactions. Depending upon the particular NP, experimental model system, and dose and exposure conditions, the introduction of NPs may have either positive or negative effects. Cellular processes such as the development of oxidative stress, the initiation of the inflammatory response, mitochondrial function, detoxification, and alterations to signaling pathways are all affected by the introduction of NPs. In terms of tissue-specific effects, the local microenvironment can have a profound effect on whether an NP is beneficial or harmful to cells. Interactions of NPs with metal-binding proteins (zinc, copper, iron and calcium) affect both their structure and function. This review will provide insights into the current knowledge of protein-based nanotoxicology and closely examines the targets of specific NPs.

Solvent Casting and UV Photocuring for Easy and Safe Fabrication of Nanocomposite Film Dressings

The aim of this work was to optimize and characterize nanocomposite films based on gellan gum methacrylate (GG-MA) and silver nanoparticles (AgNPs) for application in the field of wound dressing. The films were produced using the solvent casting technique coupled with a photocuring process. The UV irradiation of GG-MA solutions containing glycerol as a plasticizer and different amounts of silver nitrate resulted in the concurrent crosslinking of the photocurable polymer and a reduction of Ag ions with consequent in situ generation of AgNPs. In the first part of the work, the composition of the films was optimized, varying the concentration of the different components, the GG-MA/glycerol and GG-MA/silver nitrate weight ratios as well as the volume of the film-forming mixture. Rheological analyses were performed on the starting solutions, whereas the obtained films were characterized for their mechanical properties. Colorimetric analyses and swelling studies were also performed in order to determine the AgNPs release and the water uptake capacity of the films. Finally, microbiological tests were carried out to evaluate the antimicrobial efficacy of the optimized films, in order to demonstrate their possible application as dressings for the treatment of infected hard-to-heal wounds, which is a demanding task for public healthcare.

Polymer-Based Wound Dressing Materials Loaded with Bioactive Agents: Potential Materials for the Treatment of Diabetic Wounds

Diabetic wounds are severe injuries that are common in patients that suffer from diabetes. Most of the presently employed wound dressing scaffolds are inappropriate for treating diabetic wounds. Improper treatment of diabetic wounds usually results in amputations. The shortcomings that are related to the currently used wound dressings include poor antimicrobial properties, inability to provide moisture, weak mechanical features, poor biodegradability, and biocompatibility, etc. To overcome the poor mechanical properties, polymer-based wound dressings have been designed from the combination of biopolymers (natural polymers) (e.g., chitosan, alginate, cellulose, chitin, gelatin, etc.) and synthetic polymers (e.g., poly (vinyl alcohol), poly (lactic-co-glycolic acid), polylactide, poly-glycolic acid, polyurethanes, etc.) to produce effective hybrid scaffolds for wound management. The loading of bioactive agents or drugs into polymer-based wound dressings can result in improved therapeutic outcomes such as good antibacterial or antioxidant activity when used in the treatment of diabetic wounds. Based on the outstanding performance of polymer-based wound dressings on diabetic wounds in the pre-clinical experiments, the in vivo and in vitro therapeutic results of the wound dressing materials on the diabetic wound are hereby reviewed.

Pillar[5]arene-Based Acid-Triggered Supramolecular Porphyrin Photosensitizer for Combating Bacterial Infections and Biofilm Dispersion

The treatment of pathogenic bacterial infection has long been the most serious threat to human life and attracted widespread attention. Herein, a supramolecular photosensitizer platform based on carboxylatopillar[5]arene (CP5) and tetrafluorophenyl porphyrin functionalized with a quaternary ammonium group (TFPP-QA) for combating bacteria and dispersing biofilm via photodynamic treatment is constructed. By introducing the host macrocycle CP5 and host-guest interaction, the supramolecular photosensitizer has great biocompatibility and acid responsiveness. On the one hand, the acid-triggered dissociation of TFPP-QA/CP5 could induce the porphyrin photosensitizer to target bacterial cells and disrupt the charge balance of bacterial membranes, enhance the permeability of the bacterial membrane. On the other hand, the TFPP-QA/CP5 antibacterial platform possesses superb reactive oxygen species (ROS) generation capability under light irradiation, leading to enhanced photodynamic antibacterial efficacy. The in vitro and in vivo studies show that the supramolecular photosensitizers exhibit high antibacterial efficiency and biofilm dissipation effect under 660 nm light irradiation. Therefore, it is anticipated that the rational design and integration of photosensitizers and quaternary ammonium compounds through the supramolecular strategy would provide a promising prospect for clinical photodynamic antimicrobial therapy.

Functional hydrogels for diabetic wound management

Diabetic wounds often have a slow healing process and become easily infected owing to hyperglycemia in wound beds. Once planktonic bacterial cells develop into biofilms, the diabetic wound becomes more resistant to treatment. Although it remains challenging to accelerate healing in a diabetic wound due to complex pathology, including bacterial infection, high reactive oxygen species, chronic inflammation, and impaired angiogenesis, the development of multifunctional hydrogels is a promising strategy. Multiple functions, including antibacterial, pro-angiogenesis, and overall pro-healing, are high priorities. Here, design strategies, mechanisms of action, performance, and application of functional hydrogels are systematically discussed. The unique properties of hydrogels, including bactericidal and wound healing promotive effects, are reviewed. Considering the clinical need, stimuli-responsive and multifunctional hydrogels that can accelerate diabetic wound healing are likely to form an important part of future diabetic wound management.

Functional Hydrogels as Wound Dressing to Enhance Wound Healing

Hydrogels, due to their excellent biochemical and mechnical property, have shown attractive advantages in the field of wound dressings. However, a comprehensive review of the functional hydrogel as a wound dressing is still lacking. This work first summarizes the skin wound healing process and relates evaluation parameters and then reviews the advanced functions of hydrogel dressings such as antimicrobial property, adhesion and hemostasis, anti-inflammatory and anti-oxidation, substance delivery, self-healing, stimulus response, conductivity, and the recently emerged wound monitoring feature, and the strategies adopted to achieve these functions are all classified and discussed. Furthermore, applications of hydrogel wound dressing for the treatment of different types of wounds such as incisional wound and the excisional wound are summarized. Chronic wounds are also mentioned, and the focus of attention on infected wounds, burn wounds, and diabetic wounds is discussed. Finally, the future directions of hydrogel wound dressings for wound healing are further proposed.

Advancements in release-active antimicrobial biomaterials: A journey from release to relief

Escalating medical expenses due to infectious diseases are causing huge socioeconomic pressure on mankind globally. The emergence of antibiotic resistance has further aggravated this problem. Drug-resistant pathogens are also capable of forming thick biofilms on biotic and abiotic surfaces to thrive in a harsh environment. To address these clinical problems, various strategies including antibacterial agent delivering matrices and bactericidal coatings strategies have been developed. In this review, we have discussed various types of polymeric vehicles such as hydrogels, sponges/cryogels, microgels, nanogels, and meshes, which are commonly used to deliver antibiotics, metal nanoparticles, and biocides. Compositions of these polymeric matrices have been elaborately depicted by elucidating their chemical interactions and potential activity have been discussed. On the other hand, various implant/device-surface coating strategies which exploit the release-active mechanism of bacterial killing are discussed in elaboration. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease Implantable Materials and Surgical Technologies > Nanomaterials and Implants Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

A sandwich structure composite wound dressing with firmly anchored silver nanoparticles for severe burn wound healing in a porcine model

Wounds may remain open for a few weeks in severe burns, which provide an entry point for pathogens and microorganisms invading. Thus, wound dressings with long-term antimicrobial activity are crucial for severe burn wound healing. Here, a sandwich structure composite wound dressing anchored with silver nanoparticles (AgNPs) was developed for severe burn wound healing. AgNPs were in situ synthesized on the fibers of chitosan nonwoven fabric (CSNWF) as the interlayer of wound dressing for sustained release of silver ion. The firmly anchored AgNPs could prevent its entry into the body, thereby eliminating the toxicity of nanomaterials. The outer layer was a polyurethane membrane, which has a nanoporous structure that could maintain free transmission of water vapor. Chitosan/collagen sponge was selected as the inner layer because of its excellent biocompatibility and biodegradability. The presence of AgNPs in the CSNWF was fully characterized, and the high antibacterial activity of CSNWF/AgNPs was confirmed by against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The superior wound healing effect on deep dermal burns of presented composite wound dressing was demonstrated in a porcine model. Our finding suggested that the prepared AgNPs doped sandwich structure composite wound dressing has great potential application in severe wound care.

Topical delivery of chemotherapeutic drugs using nano-hybrid hydrogels to inhibit post-surgical tumour recurrence

Residual microtumours after surgical resection leading to tumour relapse is one of the major challenges for cancer therapy. Herein, we developed a nano-hybrid oligopeptide hydrogel for topical delivery of a chemotherapeutic drug, docetaxel (DTX), to inhibit the post-surgical tumour recurrence. This nano-hybrid hydrogel (DTX-CTs/Gel) was prepared by encapsulating DTX in cell-penetrating peptide-modified transfersomes followed by embedment in an oligopeptide hydrogel. The obtained DTX-CTs/Gel showed paintable and injectable properties, and could support prolonged retention at the administrated sites after topical administration. DTX-CTs released from the hydrogel presented high skin and tumour penetration capabilities, and increased the accumulation of DTX in the cancer cells leading to enhanced cell death. We showed that the topical delivery of DTX using DTX-CTs/Gel efficiently slowed down the tumour relapse in post-surgical mouse melanoma and breast tumour models.

Molecular prospect of type-2 diabetes: Nanotechnology based diagnostics and therapeutic intervention

About ninety percent of all diabetic conditions account for T2D caused due to abnormal insulin secretion/ action or increased hepatic glucose production. Factors that contribute towards the aetiology of T2D could be well explained through biochemical, molecular, and cellular aspects. In this review, we attempt to explain the recent evolving molecular and cellular advancement associated with T2D pathophysiology. Current progress fabricated in T2D research concerning intracellular signaling cascade, inflammasome, autophagy, genetic and epigenetics changes is discretely explained in simple terms. Present available anti-diabetic therapeutic strategies commercialized and their limitations which are needed to be acknowledged are addressed in the current review. In particular, the pre-eminence of nanotechnology-based approaches to nullify the inadequacy of conventional anti-diabetic therapeutics and heterogeneous nanoparticulated systems exploited in diabetic researches are also discretely mentioned and are also listed in a tabular format in the review. Additionally, as a future prospect of nanotechnology, the review presents several strategic hypotheses to ameliorate the austerity of T2D by an engineered smart targeted nano-delivery system. In detail, an effort has been made to hypothesize novel nanotechnological based therapeutic strategies, which exploits previously described inflammasome, autophagic target points. Utilizing graphical description it is explained how a smart targeted nano-delivery system could promote β-cell growth and development by inducing the Wnt signaling pathway (inhibiting Gsk3β), inhibiting inflammasome (inhibiting NLRP3), and activating autophagic target points (protecting Atg3/Atg7 complex from oxidative stress) thereby might ameliorate the severity of T2D. Additionally, several targeting molecules associated with autophagic and epigenetic factors are also highlighted, which can be exploited in future diabetic research.

Nanotechnology Approaches in Chronic Wound Healing

Significance: The incidence of chronic wounds is increasing due to our aging population and the augment of people afflicted with diabetes. With the extended knowledge on the biological mechanisms underlying these diseases, there is a novel influx of medical technologies into the conventional wound care market. Recent Advances: Several nanotechnologies have been developed demonstrating unique characteristics that address specific problems related to wound repair mechanisms. In this review, we focus on the most recently developed nanotechnology-based therapeutic agents and evaluate the efficacy of each treatment in in vivo diabetic models of chronic wound healing. Critical Issues: Despite the development of potential biomaterials and nanotechnology-based applications for wound healing, this scientific knowledge is not translated into an increase of commercially available wound healing products containing nanomaterials. Future Directions: Further studies are critical to provide insights into how scientific evidences from nanotechnology-based therapies can be applied in the clinical setting.

Carboxymethyl chitosan hydrogel formulations enhance the healing process in experimental partial-thickness (second-degree) burn wound healing

PURPOSE

This study aimed to elaborate a hydrogel constituted by carboxymethyl chitosan (CMC), hyaluronic acid (HA) and silver (Ag) and to evaluate its healing effect on partial-thickness burn wounds experimentally induced in rats.

METHODS

CMC was obtained by chitosan reacting with monochloroacetic acid. The carboxymethylation was confirmed by Fourier-transform infrared spectroscopy and hydrogen nuclear magnetic resonance (NMR). Scanning electron microscopy was used to determine the morphologicalcharacteristics of chitosan and CMC. After the experimental burn wound induction, the animals (n = 126) were treated with different CMC formulations, had their occlusive dressings changed daily and were followed through 7, 14 and 30 days. Morphometric, macroscopic and microscopic aspects and collagen quantification were evaluated.

RESULTS

Significative wound contraction, granulation tissue formation, inflammatory infiltration and collagen fibers deposit throughout different phases of the healing process were observed in the CMC hydrogels treated groups.

CONCLUSIONS

The results showed that, in the initial phase of the healing process, the most adequate product was the CMC/HA/Ag association, while in the other phases the CMC/HA association was the best one to promote the healing of burn wounds.

The effects and mechanism of Kangfuxin on improving healing quality and preventing recurrence of gastric ulcer

This study investigated the gastroprotective effects and possible mechanism of Kangfuxin (KFX), an ethanol extract of Periplaneta americana L. (Dictyoptera; Blattidae), on improving healing quality and preventing recurrence of gastric ulcer. The effects of KFX were investigated in patients treated with endoscopic submucosal dissection (ESD), gastric ulcer animal model, and rat gastric mucosal cells and fibroblasts. Moreover, the relationship between KFX and p38/NF-κB pathway were explored both in vivo and in vitro. In patients, KFX exhibited protective effects against gastric ulcers and resulted in a decrease in the CD3 expression. In vivo animal experiments confirmed that KFX accelerated ulcer healing by promoting neovascularization (increased CD34 expression), suppressing inflammation (decreased interleukin-1β (IL-1β), myeloperoxidase (MPO), tumor necrosis factor α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and IL-8 expression), and enhancing growth factor expression, including the epidermal growth factor receptor (EGFR) and hepatocyte growth factor (HGF). In vitro experiments demonstrated that treatment with 10% KFX rat serum decreased IL-1β, IL-1Ra, SIL-1RAP, TNF-α, and ICAM-1 expression in rat gastric mucosal cells or fibroblasts and increased IL-1R expression compared to that in the group treatment with 10% normal rat serum. Furthermore, KFX inhibited the activation of p38/NF-κB pathway both in vivo and in vitro. In conclusion, KFX treatment could effectively improve healing quality and prevent gastric ulcer recurrence, which might be attributed to neovascularization, suppressed inflammation, and enhanced growth factor expression. The p38/NF-κB pathway may be one of important mechanism to mediate the effects of KFX.

Antifouling Strategies of Nanoparticles for Diagnostic and Therapeutic Application: A Systematic Review of the Literature

Nanoparticles (NPs) are promising platforms for the development of diagnostic and therapeutic tools. One of the main hurdle to their medical application and translation into the clinic is the fact that they accumulate in the spleen and liver due to opsonization and scavenging by the mononuclear phagocyte system. The “protein corona” controls the fate of NPs in vivo and becomes the interface with cells, influencing their physiological response like cellular uptake and targeting efficiency. For these reasons, the surface properties play a pivotal role in fouling and antifouling behavior of particles. Therefore, surface engineering of the nanocarriers is an extremely important issue for the design of useful diagnostic and therapeutic systems. In recent decades, a huge number of studies have proposed and developed different strategies to improve antifouling features and produce NPs as safe and performing as possible. However, it is not always easy to compare the various approaches and understand their advantages and disadvantages in terms of interaction with biological systems. Here, we propose a systematic study of literature with the aim of summarizing current knowledge on promising antifouling coatings to render NPs more biocompatible and performing for diagnostic and therapeutic purposes. Thirty-nine studies from 2009 were included and investigated. Our findings have shown that two main classes of non-fouling materials (i.e., pegylated and zwitterionic) are associated with NPs and their applications are discussed here highlighting pitfalls and challenges to develop biocompatible tools for diagnostic and therapeutic uses. In conclusion, although the complexity of biofouling strategies and the field is still young, the collective data selected in this review indicate that a careful tuning of surface moieties is a pivotal step to lead NPs through their future clinical applications.

Multifunction gelatin/chitosan composite microspheres with ROS-scavenging and antibacterial activities for improving the microenvironment of chronic wounds

Multifunction gelatin/chitosan composite microspheres with ROS-scavenging and antibacterial activities for chronic wound healing.

Rational design and latest advances of polysaccharide-based hydrogels for wound healing

Acute and chronic wounds cause severe physical trauma to patients and also bring an immense socio-economic burden. Hydrogels are considered to be effective wound dressings. Polysaccharides possessing distinctive properties such as biocompatibility, biodegradability, and nontoxicity are promising candidates to structure hydrogels for wound healing. Polysaccharide-based hydrogels can provide suitable moisture for the wound and act as a shield against bacteria. Adequate mechanical properties, degradability, and therapeutic agent controlled release of polysaccharide-based hydrogels have been already characterized for effective utilization. This review presented several crucial design considerations about hydrogels for wound healing, and the current state of polysaccharide (chitosan, alginate, hyaluronic acid, cellulose, dextran, and starch)-based hydrogels as wound dressings was also summarized. The commonly used crosslinking techniques, including physical, chemical, and enzymatic crosslinking, are discussed in detail. Finally, we outline the challenges and perspectives about the improvement of polysaccharide-based hydrogels.

An Updated Review on Silver Nanoparticles in Biomedicine

Silver nanoparticles (AgNPs) represent one of the most explored categories of nanomaterials for new and improved biomaterials and biotechnologies, with impressive use in the pharmaceutical and cosmetic industry, anti-infective therapy and wound care, food and the textile industry. Their extensive and versatile applicability relies on the genuine and easy-tunable properties of nanosilver, including remarkable physicochemical behavior, exceptional antimicrobial efficiency, anti-inflammatory action and antitumor activity. Besides commercially available and clinically safe AgNPs-based products, a substantial number of recent studies assessed the applicability of nanosilver as therapeutic agents in augmented and alternative strategies for cancer therapy, sensing and diagnosis platforms, restorative and regenerative biomaterials. Given the beneficial interactions of AgNPs with living structures and their nontoxic effects on healthy human cells, they represent an accurate candidate for various biomedical products. In the present review, the most important and recent applications of AgNPs in biomedical products and biomedicine are considered.

Injectable In Situ Self-Cross-Linking Hydrogels Based on Hemoglobin, Carbon Quantum Dots, and Sodium Alginate for Real-Time Detection of Wound Bacterial Infection and Efficient Postoperative Prevention of Tumor Recurrence

Postoperative wound repair of solid tumors resection, which is afflicted by the complex tumor microenvironment (TME) and associated with the bacterial infection, is worsening and demands prompt solutions. Meanwhile, the tumor recurrence is frequently seen during the subsequent treatment due to intraoperative bleeding. For effective postoperative cancer therapy, nanoscale carriers occur as innovative and sensitive tools for monitoring the wound state, avoiding bacterial infection, and restraining tumor recurrence. Herein, a multifunctional sodium alginate (SA) hydrogel immobilizing hemoglobin (Hb) and pH-sensitive fluorescent changing carbon quantum dots (CQDs) is rationally designed. The multifunctionalization of obtained alginate@hemoglobin@CQDs hydrogel (SA@Hb@CQDs) simultaneously consists of detection, hemostasis, and chemodynamic therapy (CDT) with monitoring of wound pH based on CQDs, stanching triggered from SA hydrogel, and Fenton reaction induced by Hb. We demonstrated that SA@Hb@CQDs can stop bleeding quickly, collect wound status information in real-time, and avert bacterial infection as well as inhibit local tumor recurrence effectively. Therefore, our work provides a promising combination approach for postoperative tumor therapy.

Nanotechnology-driven advances in the treatment of diabetic wounds

Diabetic foot ulcers (DFUs) are chronic severe complications of diabetes disease and remain a worldwide clinical challenge with social and economic consequences. Diabetic wounds can cause infection, amputation of lower extremities, and even death. Several factors including impaired angiogenesis, vascular insufficiency, and bacterial infections result in a delayed process of wound healing in diabetic patients. Treatment of wound infections using traditional antibiotics has become a critical status. Thus, finding new therapeutic strategies to manage diabetic wounds is urgently needed. Nanotechnology has emerged as an efficient approach for this purpose. This review aimed to summarize recent advances using nanotechnology for the treatment of diabetic wounds.

Biodegradable Polymeric Micro/Nano-Structures with Intrinsic Antifouling/Antimicrobial Properties: Relevance in Damaged Skin and Other Biomedical Applications

Bacterial colonization of implanted biomedical devices is the main cause of healthcare-associated infections, estimated to be 8.8 million per year in Europe. Many infections originate from damaged skin, which lets microorganisms exploit injuries and surgical accesses as passageways to reach the implant site and inner organs. Therefore, an effective treatment of skin damage is highly desirable for the success of many biomaterial-related surgical procedures. Due to gained resistance to antibiotics, new antibacterial treatments are becoming vital to control nosocomial infections arising as surgical and post-surgical complications. Surface coatings can avoid biofouling and bacterial colonization thanks to biomaterial inherent properties (e.g., super hydrophobicity), specifically without using drugs, which may cause bacterial resistance. The focus of this review is to highlight the emerging role of degradable polymeric micro- and nano-structures that show intrinsic antifouling and antimicrobial properties, with a special outlook towards biomedical applications dealing with skin and skin damage. The intrinsic properties owned by the biomaterials encompass three main categories: (1) physical–mechanical, (2) chemical, and (3) electrostatic. Clinical relevance in ear prostheses and breast implants is reported. Collecting and discussing the updated outcomes in this field would help the development of better performing biomaterial-based antimicrobial strategies, which are useful to prevent infections.

Natural Polymer-Based Antimicrobial Hydrogels without Synthetic Antibiotics as Wound Dressings

Wound healing is usually accompanied by bacterial infection. The excessive use of synthetic antibiotics leads to drug resistance, posing a significant threat to human health. Hydrogel-based wound dressings aimed at mitigating bacterial infections have emerged as an effective wound treatment. The review presented herein particularly focuses on the hydrogels originating from natural polymers. To further enhance the performance of wound dressings, various strategies and approaches have been developed to endow the hydrogels with excellent broad-spectrum antibacterial activity. Those that are summarized in the current review are the hydrogels with intrinsic or stimuli-triggered bactericidal properties and others that serve as vehicles for loading antibacterial agents without synthetic antibiotics. Specific attention is paid to antimicrobial mechanisms and the antibacterial performance of hydrogels. Practical antibacterial applications to accelerate the wound healing employing these antibiotic-free hydrogels are also introduced along with the discussion on the current challenges and perspectives leading to new technologies.