Metal-organic framework (MOF)-bioactive glass (BG) systems for biomedical applications - A review

In recent years, metal-organic frameworks (MOFs) have emerged as promising materials for biomedical applications, owing to their superior chemical versatility, unique textural properties and enhanced mechanical properties. However, their fast and uncontrolled degradation, together with the reduced bioactivity have restricted their clinical potential. To overcome these limitations, MOFs can be synergistically combined with other materials, such as bioactive glasses (BGs), known for their bioactivity and therapeutic ion releasing capabilities. Besides comparing MOFs and BGs, this review aims to present the latest achievements of different MOFs/BGs materials, with a particular focus on their complementary and synergistic properties. Key findings show that combining MOFs and BGs enables the development of composite materials with superior physicochemical and biological properties. Moreover, by choosing appropriate processing techniques, BGs and MOFs can be fabricated as scaffolds or coatings with fast mineralization ability and high corrosion resistance. In addition, incorporation of MOFs/BGs in hydrogels improves mechanical stability, bioactivity and antibacterial properties, while maintaining biocompatibility. The mechanisms behind the antibacterial properties, likely coming from the release of metal ions and organic ligands, are also discussed. Overall, this review highlights the current research directions and emerging trends in the synergistic use of MOFs and BGs for biomedical applications, which represents a novel strategy for developing a new family of advanced therapeutic materials.

Bioactive glass-polymer nanocomposites: a comprehensive review on unveiling their biomedical applications

Most natural and synthetic polymers are promising materials for biomedical applications because of their biocompatibility, abundant availability, and biodegradability. Their properties can be tailored according to the intended application by fabricating composites with other polymers or ceramics. The incorporation of ceramic nanoparticles such as bioactive glass (BG) and hydroxyapatite aids in the improvement of mechanical and biological characteristics and alters the degradation kinetics of polymers. BG can be used in the form of nanoparticles, nanofibers, scaffolds, pastes, hydrogels, or coatings and is significantly employed in different applications. This biomaterial is highly preferred because of its excellent biocompatibility, bone-stimulating activity, and favourable mechanical and degradation characteristics. Different compositions of nano BG are incorporated into the polymer system and studied for positive results such as enhanced bioactivity, better cell adherence, and proliferation rate. This review summarizes the fabrication and the progress of natural/synthetic polymer-nano BG systems for biomedical applications such as drug delivery, wound healing, and tissue engineering. The challenges and the future perspectives of the composite system are also addressed.

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.

Two decades of continuous progresses and breakthroughs in the field of bioactive ceramics and glasses driven by CICECO-hub scientists

Over the past two decades, the CICECO-hub scientists have devoted substantial efforts to advancing bioactive inorganic materials based on calcium phosphates and alkali-free bioactive glasses. A key focus has been the deliberate incorporation of therapeutic ions like Mg, Sr, Zn, Mn, or Ga to enhance osteointegration and vascularization, confer antioxidant properties, and impart antimicrobial effects, marking significant contributions to the field of biomaterials and bone tissue engineering. Such an approach is expected to circumvent the uncertainties posed by methods relying on growth factors, such as bone morphogenetic proteins, parathyroid hormone, and platelet-rich plasma, along with their associated high costs and potential adverse side effects. This comprehensive overview of CICECO-hub's significant contributions to the forefront inorganic biomaterials across all research aspects and dimensionalities (powders, granules, thin films, bulk materials, and porous structures), follows a unified approach rooted in a cohesive conceptual framework, including synthesis, characterization, and testing protocols. Tangible outcomes [injectable cements, durable implant coatings, and bone graft substitutes (scaffolds) featuring customized porous architectures for implant fixation, osteointegration, accelerated bone regeneration in critical-sized bone defects] were achieved. The manuscript showcases specific biofunctional examples of successful biomedical applications and effective translations to the market of bone grafts for advanced therapies.

Effect of Silica Nanoparticle Treatment on Adhesion between Tissue-like Substrates and In Vivo Skin Wound Sealing

Silica nanoparticles are innovative solutions of surgical glue that can readily adhere to various tissue-like substrates without the need for time-consuming chemical reactions or ultraviolet irradiation. Herein, 10 nm-sized silica nanoparticle (SiNP10) treatment exhibited maximum adhesion strength in the porcine heart tissue model, which was approximately 7.15 times higher than that of the control group of non-treatment. We assessed the effects of silica nanoparticle treatment on in vivo skin wounds by scoring tissue adhesion and inflammation using histological images. Compared to the commercial cyanoacrylate skin adhesive (Dermabond), suppression of inflammatory cytokine levels in the incision wound skin was observed. We further quantified the expression of angiogenic growth factors and connective tissue formation-related proteins. On day 5 after wound closing treatment, the expression levels of PDGF-BB growth factor were significantly higher in SiNP10 treatment (0.64 ± 0.03) compared to Dermabond (0.07 ± 0.05). This stimulated angiogenesis and connective tissue formation in the skin of the incision wound may be associated with the promoting effects of SiNP10 treatment on wound closure and tissue adhesion.

Gallium-containing mesoporous nanoparticles influence in-vitro osteogenic and osteoclastic activity

Mesoporous silica nanoparticles were synthesized using a microemulsion-assisted sol-gel method, and calcium, gallium or a combination of both, were used as dopants. The influence of these metallic ions on the physicochemical properties of the nanoparticles was investigated by scanning and transmission electron microscopy, as well as N2 adsorption-desorption methods. The presence of calcium had a significant impact on the morphology and textural features of the nanoparticles. The addition of calcium increased the average diameter of the nanoparticles from 80 nm to 150 nm, while decreasing their specific surface area from 972 m2/g to 344 m2/g. The nanoparticles of all compositions were spheroidal, with a disordered mesoporous structure. An ion release study in cell culture medium demonstrated that gallium was released from the nanoparticles in a sustained manner. In direct contact with concentrations of up to 100 μg/mL of the nanoparticles, gallium-containing nanoparticles did not exhibit cytotoxicity towards pre-osteoblast MC3T3-E1 cells. Moreover, in vitro cell culture tests revealed that the addition of gallium to the nanoparticles enhanced osteogenic activity. Simultaneously, the nanoparticles disrupted the osteoclast differentiation of RAW 264.7 macrophage cells. These findings suggest that gallium-containing nanoparticles possess favorable physicochemical properties and biological characteristics, making them promising candidates for applications in bone tissue regeneration, particularly for unphysiological or pathological conditions such as osteoporosis.

Current Advances in Nanomaterials Affecting Functions and Morphology of Platelets

Nanomaterials have been extensively used in the biomedical field due to their unique physical and chemical properties. They promise wide applications in the diagnosis, prevention, and treatment of diseases. Nanodrugs are generally transported to target tissues or organs by coupling targeting molecules or enhanced permeability and retention effect (EPR) passively. As intravenous injection is the most common means of administration of nanomedicine, the transport process inevitably involves the interactions between nanoparticles (NPs) and blood cells. Platelets are known to not only play a critical role in normal coagulation by performing adhesion, aggregation, release, and contraction functions, but also be associated with pathological thrombosis, tumor metastasis, inflammation, and immune reactions, making it necessary to investigate the effects of NPs on platelet function during transport, particularly the way in which their physical and chemical properties determine their interaction with platelets and the underlying mechanisms by which they activate and induce platelet aggregation. However, such data are lacking. This review is intended to summarize the effects of NPs on platelet activation, aggregation, release, and apoptosis, as well as their effects on membrane proteins and morphology in order to shed light on such key issues as how to reduce their adverse reactions in the blood system, which should be taken into consideration in NP engineering.

The Synthesis and Characterization of Selenium-Doped Bioglass

Background Bioactive glass, which can form strong bonds with tissues, particularly bones, has become pivotal in tissue engineering. Incorporating biologically active ions like selenium enhances its properties for various biomedical applications, including bone repair and cancer treatment. Selenium's antioxidative properties and role in bone health make it a promising addition to biomaterial. Aim The present study was aimed at the preparation and characterization of selenium-doped bioglass. Materials and methods Tetraethyl orthosilicate (TEOS) was mixed with ethanol, water, and nitric acid to form a silica network and then supplemented with calcium nitrate, selenium acid sodium nitrate, and orthophosphoric acid. Sequential addition ensured specific functionalities. After sintering at 300 °C for three hours, the viscous solution transformed into powdered selenium-doped bioglass. Characterization involved scanning electron microscope (SEM) for microstructure analysis, attenuated total reflection infrared spectroscopy (ATR-IR) for molecular structure, and X-ray diffraction (XRD) for crystal structure analysis. Results SEM analysis of selenium-doped bioglass reveals a uniform distribution of selenium dopants in an amorphous structure, enhancing bioactivity through spherical particles with consistent size, micro-porosity, and roughness, facilitating interactions with biological fluids and tissues. ATR-IR analysis shows peaks corresponding to Si-O-Si and P-O bonds, indicating the presence of phosphate groups essential for biomedical applications within the bioglass network. XRD analysis confirms the amorphous nature of selenium-doped bioglass, with shifts in diffraction peaks confirming selenium incorporation without significant crystallization induction. Conclusion The selenium-infused bioglass displays promising versatility due to its amorphous structure, potentially enhancing interactions with biological fluids and tissues. Further research is needed to assess its impact on bone regeneration activity.

A win-win platform: Stabilized black phosphorous nanosheets loading gallium ions for enhancing the healing of bacterial-infected wounds through synergistic antibacterial approaches

Bacterial infection is the most common complication in wound healing, highlighting an urgent need for the development of innovative antibacterial technologies and treatments to address the growing threats posed by bacterial infections. Black phosphorus nanosheets (BPNSs), as a promising two-dimensional nanomaterial, have been utilized in treating infected wounds. However, BP's limited stability restricts its application. In this study, we enhance BP's stability and its antibacterial properties by anchoring gallium ions (Ga3+) onto BP's surface, creating a novel antibacterial platform. This modification reduces BP's electron density and enhances its antibacterial capabilities through a synergistic effect. Under near-infrared (NIR) irradiation, the BP/Ga3+ combination exerts antibacterial effects via photothermal therapy (PTT) and photodynamic therapy (PDT), while also releasing Ga3+. The Ga3+ employ a 'Trojan horse strategy' to disrupt iron metabolism, significantly boosting the antibacterial efficacy of the complex. This innovative material offers a viable alternative to antibiotics and holds significant promise for treating infected wounds and aiding skin reconstruction.

The unexplored role of alkali and alkaline earth elements (ALAEs) on the structure, processing, and biological effects of bioactive glasses

Bioactive glass has been employed in several medical applications since its inception in 1969. The compositions of these materials have been investigated extensively with emphasis on glass network formers, therapeutic transition metals, and glass network modifiers. Through these experiments, several commercial and experimental compositions have been developed with varying chemical durability, induced physiological responses, and hydroxyapatite forming abilities. In many of these studies, the concentrations of each alkali and alkaline earth element have been altered to monitor changes in structure and biological response. This review aims to discuss the impact of each alkali and alkaline earth element on the structure, processing, and biological effects of bioactive glass. We explore critical questions regarding these elements from both a glass science and biological perspective. Should elements with little biological impact be included? Are alkali free bioactive glasses more promising for greater biological responses? Does this mixed alkali effect show increased degradation rates and should it be employed for optimized dissolution? Each of these questions along with others are evaluated comprehensively and discussed in the final section where guidance for compositional design is provided.

Development of an efficient hemostatic material based on cuttlefish ink nanoparticles loaded in cuttlebone biocomposite

Traumatic hemorrhage is one of the main causes of mortality in civilian and military accidents. This study aimed to evaluate the effectiveness of cuttlefish bone (cuttlebone, CB) and CB loaded with cuttlefish ink (CB-CFI) nanoparticles for hemorrhage control. CB and CB-CFI were prepared and characterized using different methods. The hemostasis behavior of constructed biocomposites was investigated in vitro and in vivo using a rat model. Results showed that CFI nanoparticles (NPs) are uniformly dispersed throughout the CB surface. CB-CFI10 (10 mg CFI in 1.0 g of CB) showed the best blood clotting performance in both in vitro and in vivo tests. In vitro findings revealed that the blood clotting time of CB, CFI, and CB-CFI10 was found to be 275.4 ± 12.4 s, 229.9 ± 19.9 s, and 144.0 ± 17.5 s, respectively. The bleeding time in rat liver injury treated with CB, CFI, and CB-CFI10 was 158.1 ± 9.2 s, 114.0 ± 5.7 s, and 46.8 ± 2.7 s, respectively. CB-CFI10 composite resulted in more reduction of aPTT (11.31 ± 1.51 s) in comparison with CB (17.34 ± 2.12 s) and CFI (16.79 ± 1.46 s) (p < 0.05). Furthermore, CB and CB-CFI10 exhibited excellent hemocompatibility. The CB and CB-CFI did not show any cytotoxicity on human foreskin fibroblast (HFF) cells. The CB-CFI has a negative surface charge and may activate coagulation factors through direct contact with their components, including CaCO3, chitin, and CFI-NPs with blood. Thus, the superior hemostatic potential, low cost, abundant, simple, and time-saving preparation process make CB-CFI a very favorable hemostatic material for traumatic bleeding control in clinical applications.

Engineering mesoporous bioactive glasses for emerging stimuli-responsive drug delivery and theranostic applications

Mesoporous bioactive glasses (MBGs), which belong to the category of modern porous nanomaterials, have garnered significant attention due to their impressive biological activities, appealing physicochemical properties, and desirable morphological features. They hold immense potential for utilization in diverse fields, including adsorption, separation, catalysis, bioengineering, and medicine. Despite possessing interior porous structures, excellent morphological characteristics, and superior biocompatibility, primitive MBGs face challenges related to weak encapsulation efficiency, drug loading, and mechanical strength when applied in biomedical fields. It is important to note that the advantageous attributes of MBGs can be effectively preserved by incorporating supramolecular assemblies, miscellaneous metal species, and their conjugates into the material surfaces or intrinsic mesoporous networks. The innovative advancements in these modified colloidal inorganic nanocarriers inspire researchers to explore novel applications, such as stimuli-responsive drug delivery, with exceptional in-vivo performances. In view of the above, we outline the fabrication process of calcium-silicon-phosphorus based MBGs, followed by discussions on their significant progress in various engineered strategies involving surface functionalization, nanostructures, and network modification. Furthermore, we emphasize the recent advancements in the textural and physicochemical properties of MBGs, along with their theranostic potentials in multiple cancerous and non-cancerous diseases. Lastly, we recapitulate compelling viewpoints, with specific considerations given from bench to bedside.

Very Large Pore Mesoporous Bioactive Silicate Glasses: Comparison of Behavior toward Classical Mesoporous Bioactive Glasses in Terms of Drug Loading/Release and Bioactivity

Considering the increase in patients who suffer from osteoporosis and the bone defects that occur in these patients, bone tissue regeneration is a promising option to solve this problem. To achieve a synergistic effect between the synthesis of a proper structure and bioactive/pharmaceutical activity, ions with a physiological effect can be added to silica structures, such as Ca2+, thanks to its bioactive behavior, and Ga3+ for its antibacterial and anticancer action. In this work, the synthesis of large pore mesoporous silica (LPMS), potential bioactive glasses containing Ca2+ and Ga3+, has been studied. Corresponding structures, in terms of composition, have been synthesized following the Sol-Gel EISA (Evaporation Induced Self-Assembly) process (obtaining Classical Mesoporous Silica, MS). Pore structure characterization of LPMSs and MSs has been performed using N2 adsorption/desorption and Hg-porosimetry, showing the presence of pores for LPMSs in the range of 20-60 and 200-600 nm. Nisin, a polycyclic antibacterial peptide, has been used for load tests. The load and release tests performed highlight a higher loading and releasing, doubled for LPMSs if compared to MSs. To confirm the maintenance of the structure of LPMSs and their mechanical strength and resistance, scanning electron microscopy images were acquired before and after release tests. Ca and Ga release in SBF has been studied through inductively coupled plasma-optical emission spectroscopy (ICP-OES), showing a particularly high release of these ions performed with LPMSs. The bioactive behavior of Ca-containing structures has been confirmed using FT-IR (Fourier-transform infrared spectroscopy), SEM-EDS (Scanning Electron Microscope-Energy Dispersive Spectroscopy), and X-ray powder diffraction (XRDP). In conclusion, LPMSs showed better loading and releasing properties compared with classical MS and better release in terms of active ions. In addition, it has also been demonstrated that LPMSs have bioactive behavior (a well-known characteristic of MSs).

In vitro analysis of tantalum-containing mesoporous bioactive glass fibres for haemostasis

Haemorrhage is the leading cause of battlefield deaths and second most common cause for civilian mortality worldwide. Biomaterials-based haemostatic agents are used to aid in bleeding stoppage; mesoporous bioactive glasses (MBGs) are candidates for haemostasis. Previously made Tantalum-containing MBG (Ta-MBG) powders' compositions were fabricated as electrospun fibres for haemostatic applications in the present study. The fibres were fabricated to address the challenges associated with the powder form: difficult to compress without gauze, getting washed away in profuse bleeding, generating dust in the surgical environment, and forming thick callus-difficult to remove for surgeons and painful for patients. Ta-MBGs were based on (80-x)SiO2-15CaO-5P2O5-xTa2O5 mol% compositions with x = 0 (0Ta), 0.5 (0.5Ta), 1 (1Ta), and 5 (5Ta) mol%. The present study details the fibres' in vitro analyses, elucidating their cytotoxic effects, and haemostatic capabilities and relating these observations to fibre chemistry and previously fabricated powders of the same glasses. As expected, when Ta addition is increased at the expense of silica, a new FTIR peak (non-bridging oxygen-silicon, Si-NBO) develops and Si-O-Si peaks become wider. Compared to 0Ta and 1Ta fibres, 0.5Ta show Si-O peaks with reduced intensity. The fibres had a weaker intensity of Si-NBO peaks and release fewer ions than powders. A reduced ion profile provides fibres with a stable matrix for clot formation. The ion release profile for 1Ta and 5Ta fibres was significantly lower than 0Ta and 0.5Ta fibres. Ta-MBGs were not found to be cytotoxic to primary rat fibroblasts using a methyl thiazolyl tetrazolium (MTT) assay. Furthermore, a modified activated partial thromboplastin time assay analysing the fibrin absorbance showed that the absorption increases from physiological clotting < 0Ta < 0.5Ta < 5Ta < commercial haemostat, Surgical SNoWTM, Ethicon, USA < 1Ta. Higher absorption signifies a stronger clot. It is concluded that Ta-MBG fibres can provide stable matrix for clot formation and 1Ta can potentially enhance clotting best among other Ta-MBGs.

Metal-doped silicate and phosphate glasses for antibacterial dental biomaterials

Owing to the development of glass 45S5 (Bioglass®) comprising 45 mol% SiO2, 24.5 mol% Na2O, 24.5 mol% CaO, and 6 mol% P2O5, different compositions of silicate glasses have been developed. When these silicate glasses contact an aqueous environment, such as body fluids, they induce apatite layer formation on their surfaces owing to ion exchange. In addition to promoting hard tissue formation, researchers have sought to enhance the antibacterial properties of these glasses, thereby resulting in the development of metal-doped silicate glasses. The addition of antibacterial metals (silver, copper, zinc, and gallium) to silicate glass offers a promising avenue for combating oral pathogens. In recent years, there has been growing interest in metal-doped phosphate glasses. The release of metal ions can be regulated by modifying the dissolution rate of the phosphate glasses. This review summarizes the metal-doped silicate and phosphate glasses that confer antibacterial activity. Future strategies for the development of dental biomaterials that incorporate metal-doped glass and exhibit antibacterial effects are discussed.

Gallium-Containing Materials and Their Potential within New-Generation Titanium Alloys for Biomedical Applications

With the rising demand for implantable orthopaedic medical devices and the dominance of device-associated infections, extensive research into the development of novel materials has been prompted. Among these, new-generation titanium alloys with biocompatible elements and improved stiffness levels have received much attention. Furthermore, the development of titanium-based materials that can impart antibacterial function has demonstrated promising results, where gallium has exhibited superior antimicrobial action. This has been evidenced by the addition of gallium to various biomaterials including titanium alloys. Therefore, this paper aims to review the antibacterial activity of gallium when incorporated into biomedical materials, with a focus on titanium-based alloys. First, discussion into the development of new-generation Ti alloys that possess biocompatible elements and reduced Young's moduli is presented. This includes a brief review of the influence of alloying elements, processing techniques and the resulting biocompatibilities of the materials found in the literature. The antibacterial effect of gallium added to various materials, including bioglasses, liquid metals, and bioceramics, is then reviewed and discussed. Finally, a key focus is given to the incorporation of gallium into titanium systems for which the inherent mechanical, biocompatible, and antibacterial effects are reviewed and discussed in more detail, leading to suggestions and directions for further research in this area.

Sol-gel derived B2O3-CaO borate bioactive glasses with hemostatic, antibacterial and pro-angiogenic activities

Sol-gel borate bioactive glasses (BGs) are promising ion-releasing biomaterials for wound healing applications. Here, we report the synthesis of a series of binary B2O3-CaO borate BGs (CaO ranging from 50 to 90 mol%) using a sol-gel-based method. The influence of CaO content in B2O3-CaO borate BG on morphology, structure and ion release behavior was investigated in detail. Reduced dissolution (ion release) and crystallization could be observed in borate BGs when CaO content increased, while the morphology was not significantly altered by increasing CaO content. Our results evidenced that the ion release behavior of borate BGs could be tailored by tuning the B2O3/CaO molar ratio. We also evaluated the in vitro cytotoxicity, hemostatic, antibacterial and angiogenic activities of borate BGs. Cytocompatibility was validated for all borate BGs. However, borate BGs exhibited composition-dependent hemostatic, antibacterial and angiogenic activities. Generally, higher contents of Ca in borate BGs facilitated hemostatic activity, while higher contents of B2O3 were beneficial for pro-angiogenic activity. The synthesized sol-gel-derived borate BGs are promising materials for developing advanced wound healing dressings, given their fast ion release behavior and favorable hemostatic, antibacterial and angiogenic activities.

Biocompatible Gallium Nanodots against Drug-Resistant Bacterial Pneumonia and Liver Abscess

Resistant bacterial infection remains a severe public health threat, and conventional antibiotic drugs work poorly in effectively treating infectious diseases. Here, we developed gallium-based nanodots (Ga NDs), consisting of specific disruption of bacterial iron ability, to treat multidrug-resistant (MDR) Gram-negative bacteria-infected diseases. The Ga NDs significantly suppress the proliferation of two typical MDR bacteria strains (P. aeruginosa and ESBL E. coli) compared with clinically used antibacterial drugs, including penicillin and levofloxacin. Ga NDs could also disrupt the biofilms of these two bacterial strains. In P. aeruginosa infected pneumonia and ESBL E. coli infected acute liver abscess models, the Ga NDs enable substantial inhibition of bacterial growth and reduce the organs' inflammation that resulted in significant improvement of survival. Further, the Ga NDs demonstrated excellent biocompatibility and biosafety characteristics. Together, we believe that our gallium containing nanotherapeutics are expected to be developed into promising alternative therapies to combat drug-resistant bacterial infection.

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.

Chitosan-based hemostatic sponges as new generation hemostatic materials for uncontrolled bleeding emergency: Modification, composition, and applications

The choice of hemostatic technique is a curial concern for surgery and as first-aid treatment in combat. To treat uncontrolled bleeding in complex wound environments, chitosan-based hemostatic sponges have attracted significant attention in recent years because of the excellent biocompatibility, degradability, hemostasis and antibacterial properties of chitosan and their unique sponge-like morphology for high fluid absorption rate and priority aggregation of blood cells/platelets to achieve rapid hemostasis. In this review, we provide a historical perspective on the use of chitosan hemostatic sponges as the new generation of hemostatic materials for uncontrolled bleeding emergencies in complex wounds. We summarize the modification of chitosan, review the current status of preparation protocols of chitosan sponges based on various composite systems, and highlight the recent achievements on the detailed breakdown of the existing chitosan sponges to present the relationship between their composition, physical properties, and hemostatic capacity. Finally, the future opportunities and challenges of chitosan hemostatic sponges are also proposed.

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.

Exploration of Dual Ionic Cross-Linked Alginate Hydrogels Via Cations of Varying Valences towards Wound Healing

This study explored the synergistic effects of simultaneously using calcium and gallium cations in the cross-linking of alginate, detailing its effects on the characteristics of alginate compared to its single cation counterparts. The primary goal is to determine if there are any synergistic effects associated with the utilisation of multiple multivalent cations in polymer cross-linking and whether or not it could therefore be used in pharmaceutical applications such as wound healing. Given the fact divalent and trivalent cations have never been utilised together for cross-linking, an explanation for the mode of binding that occurs between the alginate and the cations during the cross-linking process and how it may affect the future applications of the polymer has been investigated. The calcium gallium alginate polymers were able to retain the antibacterial effects of gallium within the confines of the polymer matrix, possessing superior rheological properties, 6 times that of pure calcium and pure gallium, coupled with an improved swelling capacity that is 4 times higher than that of gallium alginate.

Invigorating chronic wound healing by nanocomposites composed with bioactive materials: a comprehensive review

Wound healing research has revealed a plethora of data regarding various techniques for treating diverse types of wounds. It is well known that chronic wounds heal slowly and are vulnerable to infection. Also, there are numerous factors like destitute blood passage, undetermined inflammation, angiogenesis, neuropathy, and cell multiplication which overhang chronic wound healing. To eliminate the speculative features of chronic wounds, we made a consecutive survey on specific categories of biomaterials like bioglass, bioactive glass, bioceramics, biopolymers, and biocompatible metal oxide nanoparticles. In particular, the bioglass or bioactive glass which is a silica matrix composed of sodium, calcium, phosphorous, etc., is used for bone-bonding ability and easily dissolved in vivo conditions to repair damaged and wounded tissues with their peculiar physiochemical (surface area, porous nature, structural formation, mechanical stability) and biological properties (biocompatible, cytocompatible, osteoinductive, angiogenesis, hemostatic, antibacterial, and anti-inflammation). Furthermore, based on the existing literature studies, we summarized the healing of diabetes wound tendency by bioactive composite materials and offer detailed information on the method, techniques, and future technologies for wound healing.

Gallium containing bioactive materials: A review of anticancer, antibacterial, and osteogenic properties

The incorporation of gallium into bioactive materials has been reported to enhance osteogenesis, to influence blood clotting, and to induce anti-cancer and anti-bacterial activity. Gallium-doped biomaterials prepared by various techniques include melt-derived and sol-gel-derived bioactive glasses, calcium phosphate bioceramics, metals and coatings. In this review, we summarize the recently reported developments in antibacterial, anticancer, osteogenesis, and hemostasis properties of Ga-doped biomaterials and briefly outline the mechanisms leading to Ga biological effects. The key finding is that gallium addition to biomaterials has great potential for treating bone-related diseases since it can be efficiently transferred to the desired region at a controllable rate. Besides, it can be used as a potential substitute for antibiotics for the inhibition of infections during the initial and advanced phases of the wound healing process. Ga is also used as an anticancer agent due to the increased concentration of gallium around excessive cell proliferation (tumor) sites. Moreover, we highlight the possibility to design different therapeutic approaches aimed at increasing the efficiency of the use of gallium containing bioactive materials for multifunctional applications.

Cancer Inhibition and In Vivo Osteointegration and Compatibility of Gallium-Doped Bioactive Glasses for Osteosarcoma Applications

Traditional osteosarcoma therapies tend to focus solely on eradicating residual cancer cells and often fail to promote local bone regeneration and even inhibit it due to lack of precise control over target cells, i.e., the treatment affects both normal and cancer cells. Typically, multistep procedures are required for optimal efficacy. Here, we found that a silica-based bioactive material containing 3 mol % gallium oxide selectively kills human osteosarcoma cells and presents excellent in vivo osteointegration, while showing no local or systemic toxicity. Cell culture media conditioned with the proposed material was able to kill 41% of osteosarcoma cells, and no significant deleterious effect on normal human osteoblasts was observed. In addition, rats treated with the gallium-doped material showed excellent material-bone integration with no sign of local toxicity or implant rejection. Systemic biocompatibility investigation did not indicate any sign of toxicity, with no presence of fibrosis or cellular infiltrate in the histological microstructure of the liver and kidneys after 56 days of observation. Taken together, these results show that synergistic bone regeneration and targeted cancer therapy can be combined, paving the way toward new bone cancer treatment approaches.

Bioactive inorganic particles-based biomaterials for skin tissue engineering

The challenge for treatment of severe cutaneous wound poses an urgent clinical need for the development of biomaterials to promote skin regeneration. In the past few decades, introduction of inorganic components into material system has become a promising strategy for improving performances of biomaterials in the process of tissue repair. In this review, we provide a current overview of the development of bioactive inorganic particles-based biomaterials used for skin tissue engineering. We highlight the three stages in the evolution of the bioactive inorganic biomaterials applied to wound management, including single inorganic materials, inorganic/organic composite materials, and inorganic particles-based cell-encapsulated living systems. At every stage, the primary types of bioactive inorganic biomaterials are described, followed by citation of the related representative studies completed in recent years. Then we offer a brief exposition of typical approaches to construct the composite material systems with incorporation of inorganic components for wound healing. Finally, the conclusions and future directions are suggested for the development of novel bioactive inorganic particles-based biomaterials in the field of skin regeneration.

Porcine liver injury model to assess tantalum-containing bioactive glass powders for hemostasis

This study evaluates compositions of tantalum-containing mesoporous bioactive glass (Ta-MBG) powders using a porcine fatal liver injury model. The powders based on (80-x)SiO₂-15CaO-5P₂O₅-xTa₂O₅ compositions with x = 0 (0Ta/Ta-free), 1 (1Ta), and 5 (5Ta) mol% were made using a sol-gel process. A class IV hemorrhage condition was simulated on the animals; hemodynamic data and biochemical analysis confirmed the life-threatening condition. Ta-MBGs were able to stop the bleeding within 10 min of their application while the bleeds in the absence of any intervention or in the presence of a commercial agent, Arista^TM (Bard Davol Inc., Rhode Island, USA) continued for up to 45 min. Scanning electron microscopy (SEM) imaging of the blood clots showed that the presence of Ta-MBGs did not affect clot morphology. Rather, the connections seen between fibrin fibers of the blood clot and Ta-MBG powders point towards the powders' surfaces embracing fibrin. Histopathological analysis of the liver tissue showed 5Ta as the only composition reducing parenchymal hemorrhage and necrosis extent of the tissue after their application. Additionally, 5Ta was also able to form an adherent clot in worst-case scenario bleeding where no adherent clot was seen before the powder was applied. In vivo results from the present study agree with in vitro results of the previous study that 5Ta was the best Ta-MBG composition for hemostatic purposes. Graphical abstract.

In Situ Growth of Zeolitic Imidazolate Framework-L in Macroporous PVA/CMC/PEG Composite Hydrogels with Synergistic Antibacterial and Rapid Hemostatic Functions for Wound Dressing

Although many advances have been made in medicine, traumatic bleeding and wound infection are two of the most serious threats to human health. To achieve rapid hemostasis and prevent infection by pathogenic microbes, the development of new hemostatic and antibacterial materials has recently gained significant attention. In this paper, safe, non-toxic, and biocompatible polyvinyl alcohol (PVA); carboxymethyl cellulose (CMC), which contains several carboxyl and hydroxyl groups; and polyethylene glycol (PEG), which functions as a pore-forming agent, were used to prepare a novel PVA/CMC/PEG-based composite hydrogel with a macroporous structure by the freeze-thaw method and the phase separation technique. In addition, a PVA/CMC/PEG@ZIF-L composite hydrogel was prepared by the in situ growth of zeolitic imidazolate framework-L (ZIF-L). ZIF-L grown in situ on hydrogels released Zn²⁺ and imidazolyl groups. They elicited a synergistic antibacterial effect in hemostasis with PVA and CMC, rendering the PVA/CMC/PEG@ZIF-L hydrogel with a good antibacterial effect against Staphylococcus aureus. At the same time, the macroporous structure enabled the rapid release of Zn²⁺ and imidazolyl groups in ZIF-L and promoted cell proliferation at an early stage, enhancing the coagulation efficiency. A rat liver injury model was used to confirm its rapid hemostasis capacity.

Co-doping of iron and copper ions in nanosized bioactive glass by reactive laser fragmentation in liquids

Bioactive glass (BG) is a frequently used biomaterial applicable in bone tissue engineering and known to be particularly effective when applied in nanoscopic dimensions. In this work, we employed the scalable reactive laser fragmentation in liquids method to produce nanosized 45S5 BG in the presence of light-absorbing Fe and Cu ions. Here, the function of the ions was twofold: (i) increasing the light absorption and thus causing a significant increase in laser fragmentation efficiency by a factor of 100 and (ii) doping the BG with bioactive metal ions up to 4 wt%. Our findings reveal an effective downsizing of the BG from micrometer-sized educts into nanoparticles having average diameters of <50 nm. This goes along with successful element-specific incorporation of the metal ions into the BG, inducing co-doping of Fe and Cu ions as verified by energy-dispersive X-ray spectroscopy (EDX). In this context, the overall amorphous structure is retained, as evidenced by X-ray powder diffraction (XRD). We further demonstrate that the level of doping for both elements can be adjusted by changing the BG/ion concentration ratio during laser fragmentation. Consecutive ion release experiments using inductively-coupled plasma mass spectrometry (ICP-MS) were conducted to assess the potential bioactivity of the doped nanoscopic BG samples, and cell culture experiments using MG-63 osteoblast-like cells demonstrated their cytocompatibility. The elegant method of in situ co-doping of Fe and Cu ions during BG nanosizing may provide functionality-advanced biomaterials for future studies on angiogenesis or bone regeneration, particularly as the level of doping may be adjusted by ion concentrations and ion type in solution.

In Vitro Evaluation of Real-Time Viscoelastic and Coagulation Properties of Various Classes of Topical Hemostatic Agents Using a Novel Contactless Nondestructive Technology

Hemorrhaging is the main cause of death among combat and civilian injuries and has significant clinical and economic consequences. Despite their vital roles in bleeding management, an optimal topical hemostatic agent (HA) has yet to be developed for a particular scenario. This is partly due to a lack of an overarching quantitative testing technology to characterize the various classes of HAs in vitro. Herein, the feasibility of a novel, contactless, and nondestructive technique to quantitatively measure the shear storage modulus (G') and clotting properties of whole blood in contact with different dosages of eight topical HAs, including particulates and gauze-like and sponge-like systems, was assessed. The real-time G'-time profiles of these blood/HA systems revealed their distinct biomechanical behavior to induce and impact coagulation. These were analyzed to characterize the clot initiation time, clotting rate, clotting time, and apparent stiffness of the formed clots (both immediately and temporally), which were correlated with their reported hemostatic mechanisms of action. Moreover, the HAs that worked independently from the natural blood clotting cascade were identified and quantified through this technology. In sum, this study indicated that the nondestructive nature of the technology may offer a promising tool for accurate, quantitative in vitro measurements of the clotting properties of various classes of HAs, which may be used to better predict their in vivo outcomes.

Simultaneous incorporation of gallium oxide and tantalum microparticles into micro-arc oxidation coating of titanium possessing antibacterial effect and stimulating cellular response

Orthopedic implants with both osteogenesis and antibacterial functions are particularly promising for bone repair and substitutes. In this study, a micro-arc oxidation (MAO) coating containing titanium dioxide (TiO₂), gallium oxide (Ga₂O₃) and tantalum oxide (Ta₂O₅) on the titanium surface (MGT) was fabricated by dispersing Ga₂O₃ and Ta microparticles in the electrolyte. The results showed that the simultaneous incorporation of Ga₂O₃ and Ta microparticles into the MAO coating resulted in optimized surface performance (e.g., micro-topography, roughness, wettability, surface energy, and protein absorption) of MGT compared with pure titanium (pTi). In addition, MGT exhibited outstanding corrosion resistance owing to the presence of both Ga₂O₃ and Ta microparticles, which exhibit excellent corrosion resistance and their microparticles were incorporated into the micropores of the coating. Moreover, MGT with good cytocompatibility and optimized surface resulted in improved cellular responses (e.g., proliferation and osteogenic differentiation) of rat bone mesenchymal stem cells, which was attributed to Ta microparticles with outstanding osteogenic bioactivity. Furthermore, the excellent antibacterial effect of MGT was attributed to the slow release of Ga³⁺ from the coating. Thus, the simultaneous incorporation of Ga₂O₃ and Ta microparticles into the MAO coating of MGT exhibited excellent cytocompatibility, osteogenic bioactivity, antibacterial functions, and corrosion resistance, suggesting that MGT possesses great potential for bone repair applications.

Mesoporous Bioactive Glasses in Cancer Diagnosis and Therapy: Stimuli-Responsive, Toxicity, Immunogenicity, and Clinical Translation

Cancer is one of the top life-threatening dangers to the human survival, accounting for over 10 million deaths per year. Bioactive glasses have developed dramatically since their discovery 50 years ago, with applications that include therapeutics as well as diagnostics. A new system within the bioactive glass family, mesoporous bioactive glasses (MBGs), has evolved into a multifunctional platform, thanks to MBGs easy-to-functionalize nature and tailorable textural properties-surface area, pore size, and pore volume. Although MBGs have yet to meet their potential in tumor treatment and imaging in practice, recently research has shed light on the distinguished MBGs capabilities as promising theranostic systems for cancer imaging and therapy. This review presents research progress in the field of MBG applications in cancer diagnosis and therapy, including synthesis of MBGs, mechanistic overview of MBGs application in tumor diagnosis and drug monitoring, applications of MBGs in cancer therapy ( particularly, targeted delivery and stimuli-responsive nanoplatforms), and immunological profile of MBG-based nanodevices in reference to the development of novel cancer therapeutics.

Effects and treatment applications of polymeric nanoparticles on improving platelets' storage time: a review of the literature from 2010 to 2020

Maintaining the quality of platelet products and increasing their storage time are priorities for treatment applications. The formation of platelet storage lesions that limit the storage period and preservation temperature, which can prepare a decent environment for bacterial growth, are the most important challenges that researchers are dealing with in platelet preservation. Nanotechnology is an emerging field of science that has introduced novel solutions to resolve these problems. Here, we reviewed the reported effects of polymeric nanoparticles-including chitosan, dendrimers, polyethylene glycol (PEG), and liposome-on platelets in articles from 2010 to 2020. As a result, we concluded that the presence of dendrimer nanoparticles with a smaller size, negative charge, low molecular weight, and low concentration along with PEGylation can increase the stability and survival of platelets during storage. In addition, PEGylation of platelets can also be a promising approach to improve the quality of platelet bags during storage.

Rapid hemostasis and high bioactivity cerium-containing mesoporous bioglass for hemostatic materials

A two-step-acid-catalyzed-self-assembly method was used to prepare cerium-containing mesoporous bioactive glass with P123 as a template. The results showed that MBG without cerium and MBG with cerium slightly affected its surface area, and its water absorption rate was significantly higher. In vitro coagulation experiments showed that Ce-MBG significantly reduces prothrombin time (PT) and activated partial thromboplastin time (APTT), indicating that MBG containing Ce could promote coagulation and platelet adhesion compared with MBG. These suggested that Ce-MBG may be a good dressing with hemostatic properties, which could shorten the bleeding time of the wound and control the bleeding.

Multifarious applications of bioactive glasses in soft tissue engineering

Tissue engineering (TE), a new paradigm in regenerative medicine, repairs and restores the diseased or damaged tissues and eliminates drawbacks associated with autografts and allografts. In this context, many biomaterials have been developed for regenerating tissues and are considered revolutionary in TE due to their flexibility, biocompatibility, and biodegradability. One such well-documented biomaterial is bioactive glasses (BGs), known for their osteoconductive and osteogenic potential and their abundant orthopedic and dental clinical applications. However, in the last few decades, the soft tissue regenerative potential of BGs has demonstrated great promise. Therefore, this review comprehensively covers the biological application of BGs in the repair and regeneration of tissues outside the skeleton system. BGs promote neovascularization, which is crucial to encourage host tissue integration with the implanted construct, making them suitable biomaterial scaffolds for TE. Moreover, they heal acute and chronic wounds and also have been reported to restore the injured superficial intestinal mucosa, aiding in gastroduodenal regeneration. In addition, BGs promote regeneration of the tissues with minimal renewal capacity like the heart and lungs. Besides, the peripheral nerve and musculoskeletal reparative properties of BGs are also reported. These results show promising soft tissue regenerative potential of BGs under preclinical settings without posing significant adverse effects. Albeit, there is limited bench-to-bedside clinical translation of elucidative research on BGs as they require rigorous pharmacological evaluations using standardized animal models for assessing biomolecular downstream pathways.

Hemostatic materials in wound care

Blood plays an essential role in the human body. Hemorrhage is a critical cause of both military and civilian casualties. The human body has its own hemostatic mechanism that involves complex processes and has limited capacity. However, in emergency situations such as battlefields and hospitals, when the hemostatic mechanism of the human body itself cannot stop bleeding effectively, hemostatic materials are needed for saving lives. In this review, the hemostatic mechanisms and performance of the most commonly used hemostatic materials, (including fibrin, collagen, zeolite, gelatin, alginate, chitosan, cellulose and cyanoacrylate) and the commercial wound dressings based on these materials, will be discussed. These materials may have limitations, such as poor tissue adhesion, risk of infection and exothermic reactions, that may lessen their hemostatic efficacy and cause secondary injuries. High-performance hemostatic materials, therefore, have been designed and developed to improve hemostatic efficiency in clinical use. In this review, hemostatic materials with advanced performances, such as antibacterial capacity, superhydrophobicity/superhydrophilicity, superelasticity, high porosity and/or biomimicry, will be introduced. Future prospects of hemostatic materials will also be discussed in this review.

Improved hemostatic effects by Fe3+ modified biomimetic PLLA cotton-like mat via sodium alginate grafted with dopamine

The development of an excellent, bioabsorbable hemostatic material for deep wound remains a challenge. In this work, a biodegradable cotton-like biomimetic fibrous mat of poly (l-lactic acid) (PLLA) was made by melt spinning. Subsequently, SD composite was prepared by cross-linking sodium alginate (SA) with dopamine (DA). It was immobilized on the fibre surface, which inspired by mussel byssus. Finally, Fe3+ was loaded onto the 0.5SD/PLLA composite by chelation with the carboxyl of alginate and phenolic hydroxy of dopamine. The haemostasis experiment found that the hemostatic time 47 s in vitro. However, the bleeding volume was 0.097 g and hemostatic time was 23 s when 20Fe3+-0.5SD/PLLA was applied in the haemostasis of the rat liver. As a result of its robust hydrophilicity and bouffant cotton-like structure, it could absorb a large water from blood, which could concentrate the component of blood and reduce the clotting time. Furthermore, the addition of Fe3+ in the 0.5SD/PLLA had a significant effect on improve hemostatic property. It also displayed excellent antibacterial property for Escherichia coli and Staphylococcus aureus. Notably, it possesses superior hemocompatibility, cytocompatibility and histocompatibility. Hence, 20Fe3+-0.5SD/PLLA has high potential application in haemostasis for clinical settings due to its outstanding properties.

Carbonic Anhydrase Carrying Electrospun Nanofibers for Biocatalysis Applications

BACKGROUND

Enzymes are efficient biocatalysis that catalysis a large number of reactions due to their chemical, regional, or stereo specifities and selectivity. Their usage in bioreactor or biosensor systems has great importance. Carbonic anhydrase enzyme catalyzes the interconversion between carbon dioxide and water and the dissociated ions of carbonic acid. In organisms, the carbonic anhydrase enzyme has crucial roles connected with pH and CO₂ homeostasis, respiration, and transport of CO₂/bicarbonate, etc. So, immobilization of the enzyme is important in stabilizing the catalyst against thermal and chemical denaturation in bioreactor systems when compared to the free enzyme that is unstable at high temperatures and extreme pH values, as well as in the presence of organic solvents or toxic reagents. Nano-scale composite materials have attracted considerable attention in recent years, and electrospinning based all-nanocomposite materials have a wide range of applications. In this study, electrospun nanofibers were fabricated and used for the supporting media for carbonic anhydrase enzyme immobilization to enhance the enzyme storage and usage facilities.

OBJECTIVE

In this article, our motivation is to obtain attractive electrospun support for carbonic anhydrase enzyme immobilization to enhance the enzyme reusability and storage ability in biocatalysis applications.

METHODS

In this article, we propose electrospun nanofibers for carbonic anhydrase carrying support for achieving our aforementioned object. In the first part of the study, agar with polyacrylonitrile (PAN) nanofibers was directly fabricated from an agar-PAN mixture solution using the electrospinning method, and fabricated nanofibers were cross-linked via glutaraldehyde (GA). The morphology, chemical structure, and stability of the electrospun nanofibers were characterized. In the second part of the study, the carbonic anhydrase enzyme was immobilized onto fabricated electrospun nanofibers. Then, enzyme activity, the parameters that affect enzyme immobilization such as pH, enzyme amount, immobilization time, etc. and reusability were investigated.

RESULTS

When the scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analysis results are combined in the characterization process of the synthesized electrospun nanofibers, the optimum cross-linking time is found to be 8 hours using 5% glutaraldehyde cross-linking agent. Then, thermal stability measurements showed that the thermal stability of electrospun nanofibers has an excellent characteristic for biomedical applications. The optimum temperature value was found 37°C, pH 8 was determined as an optimum pH, and 100 ppm carbonic anhydrase enzyme concentration was found to be optimum enzyme concentration for the carbonic anhydrase enzyme immobilization. According to the kinetic data, carbonic anhydrase immobilized electrospun nanofibers acted as a biocatalyst in the conversion of the substrate to the product in 83.98%, and immobilized carbonic anhydrase enzyme is reusable up to 9 cycles in biocatalysis applications.

CONCLUSION

After applying the framework, we get a new biocatalysis application platform for carbonic anhydrase enzyme. Electrospun nanofibers were chosen as the support material for enzyme immobilization. By using this approach, the carbonic anhydrase enzyme could easily be used in the industrial area by cost-effective advantageous aspects.

Removal of Pesticides from Waters by Adsorption: Comparison between Synthetic Zeolites and Mesoporous Silica Materials. A Review

Pesticides are pollutants found in wastewater due to increasing agricultural activities over the years. Inappropriate dosing of pesticides results in the dispersal of active ingredients in the environment. The complete removal of pesticides from wastewater is an immediate concern due to their high toxicity and mobility. At present, adsorption is one of the most widely used methods for pesticide removal, in which synthetic zeolites and mesoporous silica materials are extensively applied. This article presents a systematic and comparative review of the applications and comparison of these adsorbents, based on the data reported in the literature. The paper summarizes the information collected from various studies, including the type of adsorbents and pesticides used, experimental conditions, and results of each work. The studies analyzed were laboratory-based and show potential advantages for the treatment of pesticide-bearing waters using functionalized and unfunctionalized synthetic zeolites and mesoporous silica materials. As a whole, functionalized materials are reported to exhibit better removal performance for different pesticides than conventional materials. It is expected that the results of this review will help researchers to establish a powerful strategy for the abatement of pesticides in wastewater.

Mesoporous Silica Nanoparticles and Mesoporous Bioactive Glasses for Wound Management: From Skin Regeneration to Cancer Therapy

Exploring new therapies for managing skin wounds is under progress and, in this regard, mesoporous silica nanoparticles (MSNs) and mesoporous bioactive glasses (MBGs) offer great opportunities in treating acute, chronic, and malignant wounds. In general, therapeutic effectiveness of both MSNs and MBGs in different formulations (fine powder, fibers, composites etc.) has been proved over all the four stages of normal wound healing including hemostasis, inflammation, proliferation, and remodeling. The main merits of these porous substances can be summarized as their excellent biocompatibility and the ability of loading and delivering a wide range of both hydrophobic and hydrophilic bioactive molecules and chemicals. In addition, doping with inorganic elements (e.g., Cu, Ga, and Ta) into MSNs and MBGs structure is a feasible and practical approach to prepare customized materials for improved skin regeneration. Nowadays, MSNs and MBGs could be utilized in the concept of targeted therapy of skin malignancies (e.g., melanoma) by grafting of specific ligands. Since potential effects of various parameters including the chemical composition, particle size/morphology, textural properties, and surface chemistry should be comprehensively determined via cellular in vitro and in vivo assays, it seems still too early to draw a conclusion on ultimate efficacy of MSNs and MBGs in skin regeneration. In this regard, there are some concerns over the final fate of MSNs and MBGs in the wound site plus optimal dosages for achieving the best outcomes that deserve careful investigation in the future.

Bioactive glass: A multifunctional delivery system

Bioactive glasses (BAGs) were invented five decades ago and have been widely used clinically in orthopedic and stomatology. However, in the past two decades, BAGs have been explored immensely by several researchers worldwide as a multifunctional delivery system for a multitude of therapeutics ranging from metal ions to small molecules (e.g., drugs) and macromolecules (e.g., DNA). The impetus for devising a BAG-based delivery system in the 21st century is based upon the facilitative properties it offers for entrapment of a wide range of therapeutic molecules and the tailorable controlled release kinetics to the target tissue site along with the biological activity of the ionic dissolution products in several pathological conditions such as osteoporosis, cancer, infection, and inflammation. This review comprises two parts: the first part discusses the need for a new delivery system and how the journey from melt quench progressed towards template-based sol-gel mesoporous. In the second part, we have comprehended the scientific advancements made so far, emphasizing BAGs as a delivery system ranging from therapeutic ions to phytopharmaceuticals. We have also highlighted a few loopholes that have prevented bench-to-bedside clinical translation of a plethora of elucidative researches done so far.

Mesoporous zirconia surfaces with anti-biofilm properties for dental implants

Cytocompatible bioactive surface treatments conferring antibacterial properties to osseointegrated dental implants are highly requested to prevent bacteria-related peri-implantitis. Here we focus on a newly designed family of mesoporous coatings based on zirconia (ZrO₂) microstructure doped with gallium (Ga), exploiting its antibacterial and pro-osseo-integrative properties. The ZrO₂films were obtained via sol-gel synthesis route using Pluronic F127 as templating agent, while Ga doping was gained by introducing gallium nitrate hydrate. Chemical characterization by means of x-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy confirmed the effective incorporation of Ga. Then, coatings morphological and structural analysis were carried out by transmission electron microscopy and selected area electron diffraction unveiling an effective stabilization of both the mesoporous structure and the tetragonal ZrO₂phase. Specimens' cytocompatibility was confirmed towards gingival fibroblast and osteoblasts progenitors cultivated directly onto the coatings showing comparable metabolic activity and morphology in respect to controls cultivated on polystyrene. The presence of Ga significantly reduced the metabolic activity of the adhered oral pathogensPorphyromonas gingivalisandAggregatibacter actinomycetemcomitansin comparison to untreated bulk zirconia (p< 0.05); on the opposite, Ga ions did not significantly reduce the metabolism of the oral commensalStreptococcus salivarius(p> 0.05) thus suggesting for a selective anti-pathogens activity. Finally, the coatings' ability to preserve cells from bacterial infection was proved in a co-culture method where cells and bacteria were cultivated in the same environment: the presence of Ga determined a significant reduction of the bacteria viability while allowing at the same time for cells proliferation. In conclusion, the here developed coatings not only demonstrated to satisfy the requested antibacterial and cytocompatibility properties, but also being promising candidates for the improvement of implantable devices in the field of implant dentistry.

Cerium and gallium containing mesoporous bioactive glass nanoparticles for bone regeneration: Bioactivity, biocompatibility and antibacterial activity

In recent years, mesoporous bioactive glass nanoparticles (MBGNPs) have generated great attention in biomedical applications. In this study, cerium and gallium doped MBGNPs were prepared by microemulsion assisted sol-gel method in the binary SiO₂-CaO system. MBGNPs with spheroidal and pineal shaped morphology were obtained. Nitrogen sorption analysis elucidated the mesoporous structure of synthesized nanoparticles with high specific surface area. X-ray diffraction analysis confirmed the amorphous nature of the nanoparticles. The chemical compositions of all samples were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES), which revealed that the contents of cerium and gallium could be tailored by adjusting the concentrations of the precursors used for the synthesis. All MBGNPs exhibited in vitro bioactivity when immersed in simulated body fluid, except the particles doped with higher amounts than 1 mol% of cerium. MBGNPs showed antibacterial activity against S. aureus and E. coli without exhibiting cytotoxicity towards MG-63 osteoblast-like cells. Mentioned features of the obtained Ce and Ga-doped MBGNPs make them useful for multifunctional applications such as drug delivery carriers or bioactive fillers for bone tissue engineering applications.

A facile synthesis of mono dispersed spherical silver doped bioactive glass nanoparticle

Bioactive glasses have attracted enormous attention in the field of biomaterials for dental and medical applications. Incorporation of antibacterial ions within BGs has been proved to be a promising approach to fortify their bactericidal character. In this study, homogenous BGs containing silver (Ag) ions were synthesized by sol-gel method. Subsequently, the presence of the embedded ions were characterized by X-ray fluorescence (XRF) elemental analysis and energy dispersive X-ray (EDX) spectroscopy. Moreover, released ions were measured in simulated body fluid (SBF) and their antibacterial effectiveness was further verified using minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) tests. A crystalline hydroxyapatite layer was formed on the Ag-BG surfaces at day 5 approved by X-ray diffraction indicating the preserved bioactivity. The resultant uniform, mono-dispersed and dense nanoparticles show 19 great potential for a range of orthopedic and dental applications.

Study on hemostatic effect and mechanism of starch-based nano-microporous particles

The powdered hemostatic particles have broad application prospects in large open wounds, internal organ injuries and penetrating injuries of the body. In this study, nanoscale mescoporous and macroporous silica (MMSN), nanoscale mescoporous and macroporous bioactive glass (MBG), micron-scale cross-linked corn starch porous microspheres (CMS), MMSN@CMS and MBG@CMS starch-based nano-microporous particles were synthesized and their hemostatic effect and hemostatic mechanism were studied. The results showed that comparted with the single particle of CMS, the combination particles MBG@CMS and MMSN@CMS significantly increased the water absorption rate, activated both internal and external coagulation pathways, significantly shortened CBT, as well as the improved hemostatic effects in vitro. The immediately released Ca²⁺ from MBG@CMS in the blood to participate in the coagulation pathway, and MMSN@CMS activated platelets by concentrating blood coagulation factors, might be the main hemostatic mechanisms for the starch-based nano-microporous particles. Furthermore, the hemostatic efficacy of particles, both in the model of tail-amputation and liver injury in SD rats, showed the starch-based nano-microporous particles, especial MBG@CMS, could significantly reduce the weight of blood loss and shorten the bleeding time. Our research work stated that the starch-based nano-microporous particles MBG@CMS might be a hemostasis biomaterial with the potential applications for the emergency bleeding.

Porous bioactive glass micro- and nanospheres with controlled morphology: developments, properties and emerging biomedical applications

In recent years, porous bioactive glass micro/nanospheres (PBGSs) have emerged as attractive biomaterials in various biomedical applications where such engineered particles provide suitable functions, from tissue engineering to drug delivery. The design and synthesis of PBGSs with controllable particle size and pore structure are critical for such applications. PBGSs have been successfully synthesized using melt-quenching and sol-gel based methods. The morphology of PBGSs is controllable by tuning the processing parameters and precursor characteristics during the synthesis. In this comprehensive review on PBGSs, we first overview the synthesis approaches for PBGSs, including both melt-quenching and sol-gel based strategies. Sol-gel processing is the primary technology used to produce PBGSs, allowing for control over the chemical compositions and pore structure of particles. Particularly, the influence of pore-forming templates on the morphology of PBGSs is highlighted. Recent progress in the sol-gel synthesis of PBGSs with sophisticated pore structures (e.g., hollow mesoporous, dendritic fibrous mesoporous) is also covered. The challenges regarding the control of particle morphology, including the influence of metal ion precursors and pore expansion, are discussed in detail. We also highlight the recent achievements of PBGSs in a number of biomedical applications, including bone tissue regeneration, wound healing, therapeutic agent delivery, bioimaging, and cancer therapy. Finally, we conclude with our perspectives on the directions of future research based on identified challenges and potential new developments and applications of PBGSs.

Tentative identification of key factors determining the hemostatic efficiency of diatom frustule

It is increasingly essential to develop excellent materials for rapid hemorrhage control. Our previous study showed that centric diatoms such as frustules were superior to QuikClot® in hemostasis, however, related studies in pennate diatoms are still scarce. The morphological and physicochemical properties of pennate diatoms are quite different from those of centric diatoms, meaning that significant differences may also be observed from their hemostatic effects. Thus, the hemostasis effects of four pennate diatom frustules (Cocconeiopsis orthoneoides, Navicula avium, Navicula sp., and Pleurosigma indicum) were investigated in this study. Herein, all diatom frustules demonstrated outstanding hemostasis performance. For example, the in vitro coagulation time of C. orthoneoides (100.33 ± 9.5 s) was 32.4% lower than that of QuikClot®. Meanwhile, the hemostatic times of C. orthoneoides in the rat tail amputation and femoral artery models were 82 s and 180 s, respectively, only around one-half and one-third of the QuikClot® values. Moreover, the blood loss amounts of C. orthoneoides in the rat tail amputation and femoral artery model were 73.4% and 61% less than that of QuikClot®. Besides that, diatom frustules also exhibited favorable biocompatibility (hemolysis ratio <5%, MEFs cell viabilities >80%, and no inflammation). To find out the key factors underlying the hemostatic effect of frustules, Pearson correlation analysis was further performed in this study. The results demonstrated that the coagulation reaction time (R) was negatively correlated with the specific surface area and liquid absorbability but positively with the diatom pore diameter. The angle α, indicating the clot formation rate, was negative to the diatom size and pore diameter. Additionally, MA also showed a negative correlation with the BET value. This study can enrich our knowledge about the application potential of diatoms in the field of bleeding control and is helpful in deepening our understanding about the hemostatic mechanism of frustules.