One-Pot Synthesis of Silver Nanoparticle Incorporated Mesoporous Silica Granules for Hemorrhage Control and Antibacterial Treatment

Green biosynthetic silver nanoparticles from Ageratum conyzoides as multifunctional hemostatic agents: Combining hemostasis, antibacterial, and anti-inflammatory properties for effective wound healing

Widespread interest in new hemostatic agents arises from the challenge of simultaneously satisfying the requirements of hemostatic, antibacterial, and anti-inflammatory properties while also considering the associated economic costs. An ideal hemostasis material should facilitate rapid hemostasis, intervene against infection, promote wound healing, and be cost-effective and easy to prepare. Herein, we demonstrate that medicinal plant-derived silver nanoparticles (AgNPs) exhibit the potential to constitute a promising multifunctional hemostatic reagent library. Biogenic synthesis of AgNPs utilizing Ageratum conyzoides extracts, referred to as AC-AgNPs, successfully combines the hemostatic and anti-inflammatory properties of Ageratum conyzoides with the inherent antibacterial activity exhibited by AgNPs. In-vitro coagulation experiments indicate that AC-AgNPs have a strong hemostatic effect, which is related to their size, concentration, and negative charge, and they exhibit low cytotoxicity and hemolysis. Subsequent experiments including scanning electron microscopy, flow cytometry, western blotting, and network pharmacology analysis have revealed that AC-AgNPs can cause platelet activation and aggregation, stimulated kallikrein-kinin system, shorten activated partial thromboplastin and prothrombin time, and increase fibrinogen content. These findings indicate that AC-AgNPs act on multiple signaling pathways, including endogenous and exogenous coagulation pathways, complement system, platelet activation, and aggregation. Furthermore, the hemostatic efficacy of AC-AgNPs is demonstrated in mouse models of tail amputation and liver injury, where AC-AgNPs significantly reduce the amount of blood loss and the bleeding time. Our work shows that AC-AgNPs possess strong hemostatic, anti-inflammatory, and antibacterial capabilities, ultimately facilitating wound healing. The biogenic synthesis of AgNPs from medicinal plants could be a multifunctional hemostatic candidate for practical application.

From waste to Innovation: Silver-Doped silicate ink coating from waste coal fly ash for hydrophobic antimicrobial fabric and Water-Oil separation

Coal fly ash, a waste byproduct of coal-fired power plants rich in silica, is produced in vast quantities, exceeding 750 million tons annually. This abundance underscores the importance of finding sustainable and value-added applications for its reuse. Silver nanoparticle-silica composites represent a class of inorganically hybrid antimicrobial agents as the protection layer of cotton fabrics. However, prior work has seldom involved in the recycling of waste silica sources or in situ incorporation of well-defined and hierarchical Ag nanostructure. In this study, a new type of hydrophobic and antimicrobial fabric layer composed of silver-doped silicate nanomembrane was fabricated with the extraction of silica particles from waste coal fly ash by physicochemical and hydrothermal method for dual applications in personal protection and oil-water separation. The results from detailed material synthesis, soft flakes of silica extraction and formation of silver nanoparticle-based silicate revealed correlations between SiO2 and Ag having featured surface morphology and antimicrobial activity without any toxic effect to cells with polydimethoxysilane coatings. The developed fabric shows the satisfactory antimicrobial property increased up to 100% and oil-water separation performance was increased more than 90%, excellent selectivity, reversibility, reusability and stability. The compiled results have great implications for the management of solid waste like coal fly ash to biomedical and textile industry toward the production of personal protective equipment and high-performance nanomembrane for the treatment of contaminated water with oil.

Recent advances in mesoporous silica nanoparticles formulations and drug delivery for wound healing

Wound healing is a natural process that can be disrupted by disease. Nanotechnology is a promising platform for the development of new therapeutic agents to accelerate acute and chronic wound healing. Drug delivery by means of nanoparticles as well as wound dressings have emerged as suitable options to improving the healing process. The characteristics of mesoporous silica nanoparticles (MSNs) make them efficient carriers of pharmaceutical agents alone or in combination with dressings. In order to maximize the effect of a drug and minimize its adverse consequences, it may be possible to include targeted and intelligent release of the drug into the design of MSNs. Its use to facilitate closure of adjacent sides of a cut as a tissue adhesive, local wound healing, controlled drug release and induction of blood coagulation are possible applications of MSNs. This review summarizes research on MSN applications for wound healing. It includes a general overview, wound healing phases, MSN formulation, therapeutic possibilities of MSNs and MSN-based drug delivery systems for wound healing.

Surface-modified, zinc-incorporated mesoporous silica nanoparticles with improved antibacterial and rapid hemostatic properties

Severe bleeding and bacterial infections pose significant challenges to the global public health. Effective hemostatic materials have the potential to be used for rapid control of bleeding at the wound site. In this study, mesoporous silica nanoparticles (MSN) were doped with zinc ions (MSN@Zn) and subsequently functionalized with carboxyl (-COOH) groups through post-grafting, resulting in (MSN@Zn-COOH). The results demonstrated the successful functionalization of carboxyl groups on the surface of MSN@Zn mesoporous materials with minimal impact on the morphology. The released zinc ions showed potent antibacterial activity (above ∼80 %) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In vitro and in vivo assessments of MSN@Zn-COOH revealed excellent hemostatic effects and favorable blood compatibility. Hemolysis percentages associated with MSN@Zn-COOH exhibited noteworthy reductions in comparison to MSN. Furthermore, a decrease in APTT (a test evaluating the intrinsic coagulation pathway) of modified MSN@Zn indicated enhanced hemostasis, supported by their negative zeta potential (∼ -14 to -43 mV). Importantly, all samples showed no cytotoxicity. This work underscores the potential of MSN@Zn-COOH, with its combined hemostatic performance and antibacterial activity, for emergency clinical applications.

Preparation and application of hemostatic microspheres containing biological macromolecules and others

Bleeding from uncontrollable wounds can be fatal, and the body's clotting mechanisms are unable to control bleeding in a timely and effective manner in emergencies such as battlefields and traffic accidents. For irregular and inaccessible wounds, hemostatic materials are needed to intervene to stop bleeding. Hemostatic microspheres are promising for hemostasis, as their unique structural features can promote coagulation. There is a wide choice of materials for the preparation of microspheres, and the modification of natural macromolecular materials such as chitosan to enhance the hemostatic properties and make up for the deficiencies of synthetic macromolecular materials makes the hemostatic microspheres multifunctional and expands the application fields of hemostatic microspheres. Here, we focus on the hemostatic mechanism of different materials and the preparation methods of microspheres, and introduce the modification methods, related properties and applications (in cancer therapy) for the structural characteristics of hemostatic microspheres. Finally, we discuss the future trends of hemostatic microspheres and research opportunities for developing the next generation of hemostatic microsphere materials.

Bacterial cellulose-based hydrogel with antibacterial activity and vascularization for wound healing

Skin wounds need an appropriate wound dressing to help prevent bacterial infection and accelerate wound closure. Bacterial cellulose (BC) with a three-dimensional (3D) network structure is an important commercial dressing. However, how to effectively load antibacterial agents and balance the antibacterial activity is a lingering issue. Herein, this study aims to develop a functional BC hydrogel containing silver-loaded zeolitic imidazolate framework-8 (ZIF-8) antibacterial agent. The tensile strength of the prepared biopolymer dressing is >1 MPa, the swelling property is over 3000 %, the temperature can reach 50 °C in 5 min with near-infrared (NIR) and the release of Ag⁺ and Zn²⁺ is stable. In vitro investigation shows that the hydrogel displays enhanced antibacterial activity, and the bacteria survival ratios are only 0.85 % and 0.39 % against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In vitro cell experiments present that BC/polydopamine/ZIF-8/Ag (BC/PDA/ZIF-8/Ag) shows satisfactory biocompatibility and promising angiogenic ability. In vivo study, the full-thickness skin defect on rats demonstrates remarkably wound healing ability and accelerated skin re-epithelialization. This work presents a competitive functional dressing with effective antibacterial properties and accelerative angiogenesis activities for wound repair.

Nonreleasing AgNP Colloids Composite Hydrogel with Potent Hemostatic, Photodynamic Bactericidal and Wound Healing-Promoting Properties

Reactive oxygen species (ROS) produced by noble metallic nanoparticles under visible light is an effective way to combat drug-resistant bacteria colonized on the wound. However, the photocatalytic efficiency of noble metallic nanoparticles is limited by its self-aggregation in water media. Moreover, the fast release of noble metallic ions from nanoparticles might engender cellular toxicity and hazardous environmental issues. Herein, we chose AgNPs, the most common plasmonic noble metallic nanoparticles, as an example, modifying the surface of AgNPs with oleic acid and n-butylamine and imbedded them into calcium alginate (CA) hydrogel that holds tissue adhesion, rapid hemostatic, sunlight-sensitive antibacterial and anti-inflammatory abilities, and thus effectively promotes the healing of wounds. Unlike conventional AgNP-based materials, the constrain of colloids and hydrogel networks hinders the leach of Ag⁺. Nonetheless, the CA/Ag hydrogels exhibit on-demand photodynamic antibacterial efficacy due to the generation of ROS under visible light. In addition, the CA/Ag hydrogel can effectively stop the hemorrhage in a mouse liver bleeding model due to their skin-adaptive flexibility and tissue adhesiveness. The potent sunlight-responsive antibacterial activity of the CA/Ag hydrogel can effectively kill multidrug-resistant bacteria both in vitro (>99.999%) and in vivo (>99.9%), while the diminished Ag⁺ release guarantees its biocompatibility. The CA/Ag hydrogel significantly promotes the wound healing process by the downregulation of proinflammatory cytokines (TNF-α and IL-6) in a rodent full-thickness cutaneous wound model. Overall, the proposed multifunctional CA/Ag nanocomposite hydrogel has excellent prospects as an advanced wound dressing.

Yeast cell templated porous hollow silica spheres for rapid hemostasis accompanied by antibacterial action

Uncontrolled haemorrhage is the leading cause in nearly 91% of pre-hospital deaths, which were considered potentially survivable. In particular, severe trauma is susceptible to infection, which further affects the natural healing process and can even lead to life-threatening sepsis. Therefore, we established Ag@HMSN nanocomposites based on a yeast cell template that combines hemostasis with antibiosis and further studied the effects of different calcination temperatures on the hemostatic and antibacterial properties. From the experimental results, Ag@HMSNs/500 shows excellent bactericidal effect on a mouse skin infection model and outstanding hemostatic effect on a mouse liver injury model, which could be used as the next-generation hemostatic and antibacterial material.

Inorganic-based biomaterials for rapid hemostasis and wound healing

The challenge for the treatment of severe traumas poses an urgent clinical need for the development of biomaterials to achieve rapid hemostasis and wound healing. In the past few decades, active inorganic components and their derived composites have become potential clinical products owing to their excellent performances in the process of hemorrhage control and tissue repair. In this review, we provide a current overview of the development of inorganic-based biomaterials used for hemostasis and wound healing. We highlight the methods and strategies for the design of inorganic-based biomaterials, including 3D printing, freeze-drying, electrospinning and vacuum filtration. Importantly, inorganic-based biomaterials for rapid hemostasis and wound healing are presented, and we divide them into several categories according to different chemistry and forms and further discuss their properties, therapeutic mechanisms and applications. Finally, the conclusions and future prospects are suggested for the development of novel inorganic-based biomaterials in the field of rapid hemostasis and wound healing.

Silver Nanoparticle-Incorporated Defect-Engineered Zr-based Metal-Organic Framework for Efficient Multicomponent Catalytic Reactions

Small-sized silver nanoparticles are incorporated into a thiol-functionalized stable Zr-based metal-organic framework (MOF). Thiol functionalization has been carried out using 2-mercapto benzoic acid (2-MBA) as the modulator, which promotes defect formation in the MOF structure. The incorporation of silver nanoparticles aided by the silver-sulfur interactions in this defective MOF gives rise to catalytic activity. Its catalytic efficiency in the highly atom-efficient A³ coupling reaction has been studied for a variety of substrates with impressive recyclability. The synergistic effect of the electron-rich silver core and electron-deficient surface of the thiol-bonded silver nanoparticle is key for this catalytic reaction.

Dendritic Fibrous Colloidal Silica Internally Cross-linked by Bivalent Organic Cations: An Efficient Support for Dye Removal and the Reduction of Nitrobenzene Derivatives

We designed a new unique amphoteric monodisperse colloid with a large complex internal structure, in which silica surfaces are bridged with an organic cross-linker. The rationale was that such colloids would be excellent adsorbents for cationic and anionic dyes and, when doped with noble metal nanoparticles, would be an excellent catalyst for the reduction of a variety of organic compounds. In the first step, the organo-silica bridging agent (bivalent organic cross-linkers) DABCO-S (silanated DABCO) was prepared through a simple nucleophilic substitution reaction between (3-chloropropyl)triethoxysilane and bivalent 1,4-diazabicyclo[2.2.2]octane (DABCO) (a strong base). In the second step, a DABCO-S bridge was introduced into dendritic fibrous nanostructured colloidal silica (DFNS) under open-vessel reflux conditions. We refer to the product obtained by incorporating DABCO-S in DFNS as DDS. The unique characteristics of DFNS are completely preserved in this new type of periodic mesoporous organo-silica-DFNS. The produced nanocomposite has a high surface area of about 807 m² g^-1, a large pore volume of 1.9 cm³ g^-1, and a bimodal pore size distribution, with small 2.5 nm pores and large 30 nm pores. As such, DDS is an efficient adsorbent for dye removal from wastewater. The results show that DDS can adsorb positive and negative dyes such as methylene blue, orange II sodium salt (OR), and procion red mx-58 (PR) with a capacity of 678, 3192, and 3190 mg dye/g adsorbent. Introducing silver nanoparticles in situ into DDS leads to a composite with excellent accessibility of reactants to the Ag surface, resulting in an efficient catalytic reduction of nitro aromatic compounds (NACs) in aqueous media.

Haemostatic materials for wound healing applications

Wounds are one of the most common health issues, and the cost of wound care and healing has continued to increase over the past decade. The first step in wound healing is haemostasis, and the development of haemostatic materials that aid wound healing has accelerated in the past 5 years. Numerous haemostatic materials have been fabricated, composed of different active components (including natural polymers, synthetic polymers, silicon-based materials and metal-containing materials) and in various forms (including sponges, hydrogels, nanofibres and particles). In this Review, we provide an overview of haemostatic materials in wound healing, focusing on their chemical design and operation. We describe the physiological process of haemostasis to elucidate the principles that underpin the design of haemostatic wound dressings. We also highlight the advantages and limitations of the different active components and forms of haemostatic materials. The main challenges and future directions in the development of haemostatic materials for wound healing are proposed.

Green synthesized AgNPs from Periploca hydaspidis Falc. and its biological activities

Characterization of bio-synthesized silver nanoparticles (AgNPs) using Periploca hydaspidis (PHAgNPs) whole plant extract for the first time via UV-Visible spectroscopy, XRD, FTIR, DLS, and SEM analysis techniques was done. A rich variety of phytochemicals in P. hydaspidis aqueous extract (PHA) functioned as possible reducing and capping agents for AgNPs synthesis. In vitro antioxidant activities (DPPH, Iron chelating, Hydroxyl ion, Nitric oxide, and β-carotene bleaching assays) of PHAgNPs revealed least IC₅₀ values especially in hydroxyl ion (39.08 ± 0.88 μg/mL) and nitric oxide (37.53 ± 2.24 μg/mL) scavenging assays relative to standard controls (ascorbic acid, rutin, and gallic acid) and PHA. In addition, visible inhibition zone diameters were formed around discs against all pathogenic microbial strains including multi-drug resistant strains (MDR's). MIC and MBC/MFC were depicted least in PHAgNPs with maximum bactericidal/fungicidal effects. MTT assay displayed a significant antiproliferative potential of PHAgNPs against HCCLM3, MCF-7, MDA-MB 231, and HEPG2 cancer cell lines, where least IC₅₀ values were recorded against HEPG2 (12.97 ± 0.04 μg/mL) and MCF-7 (5.73 ± 0.22 μg/mL). Furthermore, PHAgNPs considerably (p > 0.001) prevented the migration of MCF-7 cancer cells in vitro whereas in in vivo wound healing assay, faster skin regeneration, and epithelization in wound biopsies was observed via histological analysis. PHAgNPs treated group rats significantly increased (p < 0.05) the wound contraction rate, hydroxyproline content and hemostatic potential compared to control and PHA-treated groups.

Metal-Organic-Framework-Based Materials for Antimicrobial Applications

To address the serious threat of bacterial infection to public health, great efforts have been devoted to the development of antimicrobial agents for inhibiting bacterial growth, preventing biofilm formation, and sterilization. Very recently, metal-organic frameworks (MOFs) have emerged as promising materials for various antimicrobial applications owing to their different functions including the controlled/stimulated decomposition of components with bactericidal activity, strong interactions with bacterial membranes, and formation of photogenerated reactive oxygen species (ROS) as well as high loading and sustained releasing capacities for other antimicrobial materials. This review focuses on recent advances in the design, synthesis, and antimicrobial applications of MOF-based materials, which are classified by their roles as component-releasing (metal ions, ligands, or both), photocatalytic, and chelation antimicrobial agents as well as carriers or/and synergistic antimicrobial agents of other functional materials (antibiotics, enzymes, metals/metal oxides, carbon materials, etc.). The constituents, fundamental antimicrobial mechanisms, and evaluation of antimicrobial activities of these materials are highlighted to present the design principles of efficient MOF-based antimicrobial materials. The prospects and challenges in this research field are proposed.

Rapid hemostasis accompanied by antibacterial action of calcium crosslinking tannic acid-coated mesoporous silica/silver Janus nanoparticles

It is important to control bleeding and prevent bacterial infection for the wound people. The effective way is to fabricate an asymmetric Janus matrial for realizing rapid hemostasis and promoting wound healing. Herein, mesoporous silica nanoparticles (MSN) modified by tannic acid (TA), silver nanoparticles, and calcium ions (Ca-TA-MSN@Ag) with Janus structure were prepared via redox and coordination reactions. These anisotropic snowman-like particles possess obvious chemical compartition, in which silver nanoparticles are embedding in large MSN body. During blood coagulation, TA with catechol structure acts as a vasoconstrictor. Then, Ca-TA-MSN@Ag with high specific surface area (510.62 m²·g^-1) and large pore volume (0.48 m³·g^-1) induces red blood cell aggregation to form three-dimensional network structure with fibrin. Additionally, calcium ions as clotting factor IV and negative charge of Ca-TA-MSN@Ag accelerate coagulation cascade reaction. These three synergistic effects on animal model showed that hemostatic time of Ca-TA-MSN@Ag was shortened by nearly 50% compared to that of MSN. Moreover, Ca-TA-MSN@Ag possessed good blood compatibility, biocompatibility and antibacterial activity (~99%) against E. coli and S. aureus. The anisotropic Janus particles of Ca-TA-MSN@Ag with hemostatic performance and antibacterial activity will be a promising biomaterial for designing wound dressings in clinical application.

Click-Grafting of Cardanol onto Mesoporous Silica/Silver Janus Particles for Enhanced Hemostatic and Antibacterial Performance

Janus particles with obvious chemical compartition can perform their functions independently, so they have attracted much attention in biomedical materials. Herein, a mesoporous silica/silver Janus nanoparticle modified with cardanol (C-MSN@Ag) was designed and synthesized via redox and click chemical reactions and was further evaluated as a highly efficient hemostatic dressing. This Janus structure endowed C-MSN@Ag with both prominent hemostatic and antibacterial performance. The hemostatic time of C-MSN@Ag on rat liver laceration was up to 40% shorter than that of MSN and MSN@Ag because of adhesion of phenolic compounds on the tissue and the blocking effect of the hydrophobic alkyl chains from cardanol. Besides, C-MSN@Ag could promote coagulation by forming a three-dimensional network with fibrin more quickly than MSN and MSN@Ag. Additionally, due to the released silver ions and phenolic hydroxyl groups of cardanol, C-MSN@Ag exhibited a broad-spectrum antibacterial rate (∼99%) against both Escherichia coli and Staphylococcus aureus. C-MSN@Ag also possessed non-cytotoxicity. This work not only provides a way for the fabrication of silica-based Janus hemostatic agents by the atom-economical click reaction but also gives a direction for the application of the sustainable naturally occurring cardanol.

A dual-functional implant with an enzyme-responsive effect for bacterial infection therapy and tissue regeneration

Biomaterial-associated bacterial infection is one of the major causes of implant failure. The treatment of such an implant infection typically requires the elimination of bacteria and acceleration of tissue regeneration around implants simultaneously. To address this issue, an ideal implanted material should have the dual functions of bacterial infection therapy and tissue regeneration at the same time. Herein, an enzyme-responsive nanoplatform was fabricated in order to treat implant-associated bacterial infection and accelerate tissue regeneration in vivo. Firstly, Ag nanoparticles were pre-encapsulated in mesoporous silica nanoparticles (MSNs) by a one-pot method. Then, poly-l-glutamic acid (PG) and polyallylamine hydrochloride (PAH) were assembled by the layer-by-layer (LBL) assembly technique on MSN-Ag to form LBL@MSN-Ag nanoparticles. Furthermore, the LBL@MSN-Ag nanoparticles were deposited on the surface of polydopamine-modified Ti substrates. PG is a homogeneous polyamide composed of an amide linkage, which can be degraded by glutamyl endonuclease secreted by Staphylococcus aureus. Inductively coupled plasma spectroscopy (ICP) results proved that the LBL@MSN-Ag particles show a significant enzyme responsive release of Ag ions. Furthermore, results of antibacterial experiments in vitro showed that the Ti substrates modified with an LBL@MSN-Ag nanocoating presented an excellent antibacterial effect. As for an animal experiment in vivo, in a bacterium infected femur-defect rat model, the modified Ti implants effectively treated bacterial infection. More importantly, the results of micro-CT, haematoxylin-eosin staining and Masson's trichrome staining demonstrated that the modified Ti implants significantly promoted the formation of new bone tissue after implantation for 4 weeks. The present system paves the way for developing the next generation of implants with the functions of treating bacterial infection and promoting tissue regeneration.

Construction of selenium-embedded mesoporous silica with improved antibacterial activity

In this work, different concentrations of Se-incorporated mesoporous silica nanospheres (MSNs) (5Se/MSNs and 10Se/MSNs) were successfully synthesized via an in-situ one-pot method. Their physicochemical properties were characterized by X-ray diffraction (XRD), transmission electron microscopy, and X-ray photoelectron spectroscopy (XPS). The release behaviors of Se and Si were investigated in a phosphate-buffered saline (pH = 5.5, 7.4) solution (PBS). In vitro antibacterial properties of the prepared samples were evaluated with Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The cytocompatibilities of the samples were then assessed using L929 cells. Se nanoparticles were successfully loaded onto the outer and inner surfaces of hierarchical mesoporous silica. The sizes of the Se/MSNs nanoparticles were approximately 120 nm for 5Se/MSNs and 210 nm for 10Se/MSNs. The XRD and XPS results showed that Se mainly existed in the form of Se⁰ in the samples. The Se/MSNs exhibited stable and sustained release of both Si and Se in PBS solution. In vitro antibactericidal tests indicated that the Se/MSNs could exhibit better antibacterial activity against S. aureus than pure Se nanoparticles after 6 and 24 h of culturing. The minimal inhibitory concentration (MIC) of 10Se/MSN was 100 μg mL^-1. However, the Se/MSNs exhibited no inhibitory effect on E. coli bacteria. Furthermore, all the samples exhibited excellent cell viability. These studies demonstrate initial in vitro antibacterial activity and good cytocompatibility of Se/MSNs and their potential application in antibacterial nanomedicine.

Oxidized cellulose-based hemostatic materials

The application of hemostatic agents is essential to prevent significant blood loss and death from excessive bleeding in surgical or emergency scenarios. Oxidized cellulose is an excellent biodegradable and biocompatible derivate of cellulose, which has become one of the most important hemostatic agents used in surgical procedures. However, to date, there has been no comprehensive report assessing oxidized cellulose-based hemostatic materials. Hence, this paper first reviewed the oxidation preparation, cellulose origin and structure, as well as biodegradability and safety of oxidized cellulose. Then a comprehensive review regarding the hemostatic mechanisms, various forms, modification, and current commercially available products of oxidized cellulose is discussed, which emphatically presents the most significant developments in the recent scientific literature. In conclusion, this paper summarizes the latest developments in oxidized cellulose-based hemostatic materials and provides a reference for further research and development in this field.

Mesoporous silica nanoparticles for tissue-engineering applications

Mesoporous silica nanoparticles (MSNs) have been widely investigated as a nanocarrier for the delivery of various cargoes in nanomedicine. The application of MSNs in tissue engineering is a relatively newly emerged field that has gained much research interest. In this review, the recent advances in the tissue-engineering application of MSNs are summarized. The controlled synthesis of MSNs is delineated first in terms of tuning the morphology, pore size of MSNs, and its surface chemistry, as well as biodegradability. Then, the different roles of MSNs in tissue engineering are successively introduced, which mainly comprise the delivery of bioactive factors, the inherent bioactivity of MSNs, stem cells labelling, and the impacts of incorporated MSNs on scaffolds. Furthermore, the recent progress in the applications of MSNs for tissue engineering, particularly bone tissue engineering, is summarized in detail. Finally, the challenges or potential trends for the further applications of MSNs in tissue engineering are also discussed. This article is categorized under: Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Implantable Materials and Surgical Technologies > Nanomaterials and Implants.

Ultrafine Silver Nanoparticles Embedded in Cyclodextrin Metal-Organic Frameworks with GRGDS Functionalization to Promote Antibacterial and Wound Healing Application

The challenge of bacterial infection increases the risk of mortality and morbidity in acute and chronic wound healing. Silver nanoparticles (Ag NPs) are a promising new version of conventional antibacterial nanosystem to fight against the bacterial resistance in concern of the drug discovery void. However, there are several challenges in controlling the size and colloidal stability of Ag NPs, which readily aggregate or coalesce in both solid and aqueous state. In this study, a template-guided synthesis of ultrafine Ag NPs of around 2 nm using water-soluble and biocompatible γ-cyclodextrin metal-organic frameworks (CD-MOFs) is reported. The CD-MOF based synthetic strategy integrates AgNO₃ reduction and Ag NPs immobilization in one pot achieving dual functions of reduced particle size and enhanced stability. Meanwhile, the synthesized Ag NPs are easily dispersible in aqueous media and exhibit effective bacterial inhibition. The surface modification of cross-linked CD-MOF particles with GRGDS peptide boosts the hemostatic effect that further enhances wound healing in synergy with the antibacterial effect. Hence, the strategy of ultrafine Ag NPs synthesis and immobilization in CD-MOFs together with GRGDS modification holds promising potential for the rational design of effective wound healing devices.