MOFs and MOF-Based Composites as Next-Generation Materials for Wound Healing and Dressings.

In recent years, there has been growing interest in developing innovative materials and therapeutic strategies to enhance wound healing outcomes, especially for chronic wounds and antimicrobial resistance. Metal-organic frameworks (MOFs) represent a promising class of materials for next-generation wound healing and dressings. Their high surface area, pore structures, stimuli-responsiveness, antibacterial properties, biocompatibility, and potential for combination therapies make them suitable for complex wound care challenges. MOF-based composites promote cell proliferation, angiogenesis, and matrix synthesis, acting as carriers for bioactive molecules and promoting tissue regeneration. They also have stimuli-responsivity, enabling photothermal therapies for skin cancer and infections. Herein, a critical analysis of the current state of research on MOFs and MOF-based composites for wound healing and dressings is provided, offering valuable insights into the potential applications, challenges, and future directions in this field. This literature review has targeted the multifunctionality nature of MOFs in wound-disease therapy and healing from different aspects and discussed the most recent advancements made in the field. In this context, the potential reader will find how the MOFs contributed to this field to yield more effective, functional, and innovative dressings and how they lead to the next generation of biomaterials for skin therapy and regeneration.

Silica-based nanosystems against antibiotic-resistant bacteria and pathogenic viruses.

Today, with the intensity of antibiotic abuse and self-medication, the need for the use of novel systems with high efficiency and biosafety for targeted drug delivery against antibiotic-resistant bacteria and their infections should be highly considered by researchers. Silica-based nanosystems with unique physicochemical properties such as large surface area, tuneable pore diameter, drug loading capacity, controlled particle size/morphology, and good biocompatibility are attractive candidates against antibiotic-resistant bacteria and pathogenic viruses. They can be loaded with antiviral and antimicrobial drugs or molecules through their exclusive internal porous structures or different surface linkers. In this context, smart nanosystems can be produced via suitable surface functionalization/modification with a variety of functional groups to act against different clinical pathogenic microbes or viruses, offering great opportunities for controlling and treating various infections. However, important criteria such as the ability to degrade, biocompatibility, biodegradability, cytotoxicity, stability, clearance from targeted organs should be systematically analysed to develop nanosystems or nanocarriers with high efficiency and multifunctionality. Herein, recent advancements pertaining to the application of silica-based nanosystems against antibiotic-resistant bacteria and pathogenic viruses are deliberated, focussing on important challenges and future perspectives.

Role of MXenes in advancing soft robotics.

MXenes with their unique electronic, optical, chemical, and mechanical properties have shown great promise in soft robotics. MXene-based soft actuators have been designed to display ultrafast actuations and recovery speeds as well as angle-independent structural colors in response to vapor. Several studies have developed soft actuators by combining MXenes with other materials to mimic the movement of natural organisms. Thus, MXene-based soft actuators have the potential to revolutionize the field of soft robotics and flexible electronics (e.g., wearable devices and artificial muscles). MXene-based artificial muscles have been explored for use in kinetic soft robotics as actuators in microsystems requiring exceptional compliance. MXene-based sensors and actuators have already been developed for human-like sensors and photodetection. However, there are still challenges that need to be addressed in such applications, such as the design of stretchable and compliant robotic skins with a high-level functional integration for soft robotics. The integration of various devices, such as power sources, sensors, and actuators, into soft robotics is another crucial challenge. Despite the excellent stretchability and tensile strength of MXene-based composites, there is a vital need to develop their mechanical and electrochemical features and grant them multi-functionalities. Herein, recent developments pertaining to the applications of MXenes and their composites in soft robotics are discussed with a focus on the important challenges and future perspectives.

Nanophotocatalysts in biomedicine: Cancer therapeutic, tissue engineering, biosensing, and drug delivery applications.

Photocatalysis can be considered as a green technology owing to its excellent potential for sustainability and fulfilling several principles of green chemistry. This process uses light radiation as the primary energy source, preventing or reducing the requirement for artificial light sources and exogenous catalytic entities. Photocatalysis has promising applications in biomedicine such as drug delivery, biosensing, tissue engineering, cancer therapeutics, etc. In targeted cancer therapeutics, photocatalysis can be employed in photodynamic therapy to form reactive oxygen species that damage cancerous cells' structure. Nanophotocatalysts can be used in targeted drug delivery, showing potential applications in nuclear-targeted drug delivery along with specific delivery of chemotherapeutics to cancer cells or tumor sites. On the other hand, in tissue engineering, nanophotocatalysts can be employed in designing scaffolds that promote cell growth and tissue regeneration. However, some important challenges pertaining to the performance of photocatalysis, large-scale production of nanophotocatalysts, optimization of reaction/synthesis conditions, long-term biosafety issues, stability, clinical translation, etc. still need further explorations. Herein, the most recent advancements pertaining to the biomedical applications of nanophotocatalysts are reflected, focusing on drug delivery, tissue engineering, biosensing, and cancer therapeutic potentials.

Natural resources for sustainable synthesis of nanomaterials with anticancer applications: A move toward green nanomedicine.

Today, researchers have focused on the application of environmentally-benign and sustainable micro- and nanosystems for drug delivery and cancer therapy. Compared to conventional chemotherapeutics, advanced micro- and nanosystems designed by applying abundant, natural, and renewable feedstocks have shown biodegradability, biocompatibility, and low toxicity advantages. However, important aspects of toxicological assessments, clinical translational studies, and suitable functionalization/modification still need to be addressed. Herein, the benefits and challenges of green nanomedicine in cancer nanotherapy and targeted drug delivery are cogitated using nanomaterials designed by exploiting natural and renewable resources. The application of nanomaterials accessed from renewable natural resources, comprising metallic nanomaterials, carbon-based nanomaterials, metal-organic frameworks, natural-derived nanomaterials, etc. for targeted anticancer drug delivery and cancer nanotherapy are deliberated, with emphasis on important limitations/challenges and future perspectives.

ZnO/black phosphorus/C3N4 composite: An effective photocatalyst for Cr (VI) reduction and degradation of rhodamine B.

The utilization of photocatalysts offers a promising approach for the removal of Cr (VI) and rhodamine dyes. Through the generation of reactive species and subsequent degradation reactions, photocatalysis provides an efficient and environmentally friendly method for the remediation of wastewater. In this study, we have synthesized an n-p-n heterojunction of carbon nitride (C3N4), zinc oxide (ZnO), and black phosphorus (BP) through the sonication-stirring method. The photocatalytic ability of this composite was examined for the decomposition rhodamine B (RhB) and detoxification of hexavalent chromium ion (up to 97% during 80 min) under Xenon irradiation. The results of trapper experiments indicated that the active species were hydroxyl radical (˙OH), electron (e-), and superoxide anion radical (˙O2-). Based on the obtained potential of the lowest unoccupied molecular orbitals (LUMO) and the highest occupied molecular orbital (HOMO) for the mentioned semiconductors, through Mutt-Schottky results, the double Z-scheme mechanism was proposed for the studied process. The electrochemical impedance spectroscopy data exhibited good charge transfer for the evaluated composite versus the pure compounds. The impressive separation of holes and electrons along with the low recombination were confirmed by the responses of photocurrent and quenching the photoluminescence (pl) intensity for the composite, respectively. The current density of the composite recorded 66.6%, 87.3%, and 92% higher than those of BP, C3N4, and ZnO, indicating an excellent electron-hole separation for the ternary composite compared to the pure semiconductors. Diffuse reflectance spectra (DRS) data revealed 2.9, 3.17, 1.15, and 2.63 eV as the band gap values for C3N4, ZnO, BP, and composite. The rate constant of the new composite to remove RhB and reduce hexavalent chromium were about 4.79 and 2.64 times higher than that of C3N4, respectively.

Black Phosphorus-based Photocatalysts: Synthesis, Properties, and Applications.

Photocatalysis is considered as an eco-friendly and sustainable strategy, since it uses abundant light for the advancement of the reaction, which is freely accessible and is devoid of environmental pollution. During the last decades, (nano)photocatalysts have gained broad industrial applications in terms of purification and detoxification of water as well as production of green fuels and hydrogen gas due to their special attributes. The degradation or remediation of toxic and hazardous compounds from the environment or changing them into non-toxic entities is a significant endeavor and necessary for the safety of humans, animals, and the environment. Black phosphorus (BP), a two-dimensional single-element material, has a marvelous structure, tunable bandgap, changeable morphology from bulk to nanosheet/quantum dot, and unique physicochemical properties, which makes it attractive material for photocatalytic applications, especially for sustainable development purposes. Since it can serve as a photocatalyst with or without coupling with other semiconductors, various aspects for multidimensional exploitation of BP are deliberated including their preparation via solvothermal, ball milling, calcination, and sonication methods to obtain BP from red phosphorus. The techniques for improving the photocatalytic and stability of BP-based composites are discussed along with their multifaceted applications for environmental remediation, pollution degradation, water splitting, N2 fixation, CO2 reduction, bacterial disinfection, H2 generation, and photodynamic therapy. Herein, most recent advancements pertaining to the photocatalytic applications of BP-based photocatalyst are cogitated, with a focus on their synthesis and properties as well as crucial challenges and future perspectives.

MOF-based composites as photoluminescence sensing platforms for pesticides: Applications and mechanisms.

Metal-organic frameworks (MOFs) have recently garnered considerable attention among reticular compounds due to their unique physicochemical properties and applications in sensing toxic compounds. On the other hand, fluorometric sensing has been widely studied for food safety and environmental protection among the various sensing methods. Thus, designing MOF-based fluorescence sensors for specific detection of hazardous compounds, especially pesticides, are incessantly needed to keep up with the continuous demands for monitoring these environmental pollution. Herein, recent MOF-based platforms for pesticide fluorescence detection are deliberated owing to sensors' emission origins and in terms of their structural properties. The influences of different guest incorporation in MOFs on pesticide fluorescence detection are summarized, and the future developments of novel MOF composites such as polyoxometalate@MOFs (POMOF), carbon quantum dots@MOFs (CDs@MOF), and organic dye@MOF are prospected for fluorescence sensing of assorted pesticides with a focus on mechanistic insights of specific detection techniques in food safety and environmental protection.

Alginate-Based Biomaterials in Tissue Engineering and Regenerative Medicine.

Today, with the salient advancements of modern and smart technologies related to tissue engineering and regenerative medicine (TE-RM), the use of sustainable and biodegradable materials with biocompatibility and cost-effective advantages have been investigated more than before. Alginate as a naturally occurring anionic polymer can be obtained from brown seaweed to develop a wide variety of composites for TE, drug delivery, wound healing, and cancer therapy. This sustainable and renewable biomaterial displays several fascinating properties such as high biocompatibility, low toxicity, cost-effectiveness, and mild gelation by inserting divalent cations (e.g., Ca2+). In this context, challenges still exist in relation to the low solubility and high viscosity of high-molecular weight alginate, high density of intra- and inter-molecular hydrogen bonding, polyelectrolyte nature of the aqueous solution, and a lack of suitable organic solvents. Herein, TE-RM applications of alginate-based materials are deliberated, focusing on current trends, important challenges, and future prospects.

Nanophotocatalysts against viruses and antibiotic-resistant bacteria: recent advances.

Photocatalysis has attracted great attention because of its direct utilisation of sunlight to obtain various chemical reactions, causing water splitting, organic pollutant degradation, and water disinfection. Nanophotocatalysts can be employed for various applications, including hydrogen storage, green diesel production, fuel cell applications, industrial manufacturing methods, pharmaceutical industries, and catalytic degradation of contaminants/hazardous materials. Photocatalytic inactivation and removal of pathogenic viruses, antibiotic-resistant bacteria and antibiotic resistance genes can be considered as simple and effective technique with low-cost, eco-friendliness, and low energy consumption features. The high specific surface areas, abundant functional groups, large amounts of active sites are some advantages of the nanostructures for photocatalytic activity with high efficiency. However, some important limitations/drawbacks of nanophotocatalysts for industrial and commercial applications such as the low selectivity, aggregation/sedimentation, difficult separation, low-usage of visible light, fast charge recombination, and low migration potential of photogenerated electrons/holes are need to be comprehensively and analytically investigated and addressed by researchers. This critical review highlighted the recent advancements in photocatalytic disinfection of pathogenic viruses and antibiotic-resistant bacteria, focussing on the development of highly efficient nanophotocatalysts and their underlying mechanisms of inactivation/removal of these pathogens.

Alginate-Based Micro- and Nanosystems for Targeted Cancer Therapy.

Alginates have been widely explored due to their salient advantages of hydrophilicity, biocompatibility, mucoadhesive features, bioavailability, environmentally-benign properties, and cost-effectiveness. They are applied for designing micro- and nanosystems for controlled and targeted drug delivery and cancer therapy as alginate biopolymers find usage in encapsulating anticancer drugs to improve their bioavailability, sustained release, pharmacokinetics, and bio-clearance. Notably, these nanomaterials can be applied for photothermal, photodynamic, and chemodynamic therapy of cancers/tumors. Future explorations ought to be conducted to find novel alginate-based (nano)systems for targeted cancer therapy using advanced drug delivery techniques with benefits of non-invasiveness, patient compliance, and convenience of drug administration. Thus, some critical parameters such as mucosal permeability, stability in the gastrointestinal tract environment, and drug solubility ought to be considered. In addition, the comprehensive clinical translational studies along with the optimization of synthesis techniques still need to be addressed. Herein, we present an overview of the current state of knowledge and recent developments pertaining to the applications of alginate-based micro- and nanosystems for targeted cancer therapy based on controlled drug delivery, photothermal therapy, and chemodynamic/photodynamic therapy approaches, focusing on important challenges and future directions.

Cytotoxicity properties of plant-mediated synthesized K-doped ZnO nanostructures.

In this study, potassium-doped zinc oxide nanoparticles (K-doped ZnO NPs) were green-synthesized using pine pollen extracts based on bioethics principles. The synthesized NPs were analyzed using X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDXA), and transmission electron microscopy (TEM). The cytotoxicity of these nanoparticles (NPs) on normal macrophage cells and cancer cell lines was evaluated. In the same concentrations of K-doped ZnO and pure ZnO NPs, K-doped ZnO NPs demonstrated higher toxicity. The results confirmed that the doped potassium could increase cytotoxicity. The IC50 of K-doped ZnO NPs, pure ZnO NPs, and the examined control drug were 497 ± 15, 769 ± 12, and 606 ± 19 µg/mL, respectively. Considering the obtained IC50 of K-doped ZnO NPs, they were more toxic to the cancer cell lines and had less cytotoxicity on normal macrophage cells.

Quantum dots against SARS-CoV-2: diagnostic and therapeutic potentials.

The application of quantum dots (QDs) for detecting and treating various types of coronaviruses is very promising, as their low toxicity and high surface performance make them superior among other nanomaterials; in conjugation with fluorescent probes they are promising semiconductor nanomaterials for the detection of various cellular processes and viral infections. In view of the successful results for inhibiting SARS-CoV-2, functional QDs could serve eminent role in the growth of safe nanotherapy for the cure of viral infections in the near future; their large surface areas help bind numerous molecules post-synthetically. Functionalized QDs with high functionality, targeted selectivity, stability and less cytotoxicity can be employed for highly sensitive co-delivery and imaging/diagnosis. Besides, due to the importance of safety and toxicity issues, QDs prepared from plant sources (e.g. curcumin) are much more attractive, as they provide good biocompatibility and low toxicity. In this review, the recent developments pertaining to the diagnostic and inhibitory potentials of QDs against SARS-CoV-2 are deliberated including important challenges and future outlooks. © 2022 Society of Chemical Industry (SCI).

Cellulose-Based Composites as Scaffolds for Tissue Engineering: Recent Advances.

Today, numerous studies have focused on the design of novel scaffolds for tissue engineering and regenerative medicine applications; however, several challenges still exist in terms of biocompatibility/cytocompatibility, degradability, cell attachment/proliferation, nutrient diffusion, large-scale production, and clinical translation studies. Greener and safer technologies can help to produce scaffolds with the benefits of cost-effectiveness, high biocompatibility, and biorenewability/sustainability, reducing their toxicity and possible side effects. However, some challenges persist regarding their degradability, purity, having enough porosity, and possible immunogenicity. In this context, naturally derived cellulose-based scaffolds with high biocompatibility, ease of production, availability, sustainability/renewability, and environmentally benign attributes can be applied for designing scaffolds. These cellulose-based scaffolds have shown unique mechanical properties, improved cell attachment/proliferation, multifunctionality, and enhanced biocompatibility/cytocompatibility, which make them promising candidates for tissue engineering applications. Herein, the salient developments pertaining to cellulose-based scaffolds for neural, bone, cardiovascular, and skin tissue engineering are deliberated, focusing on the challenges and opportunities.

MXene-Based Photocatalysts in Degradation of Organic and Pharmaceutical Pollutants.

These days, explorations have focused on designing two-dimensional (2D) nanomaterials with useful (photo)catalytic and environmental applications. Among them, MXene-based composites have garnered great attention owing to their unique optical, mechanical, thermal, chemical, and electronic properties. Various MXene-based photocatalysts have been inventively constructed for a variety of photocatalytic applications ranging from pollutant degradation to hydrogen evolution. They can be applied as co-catalysts in combination with assorted common photocatalysts such as metal sulfide, metal oxides, metal-organic frameworks, graphene, and graphitic carbon nitride to enhance the function of photocatalytic removal of organic/pharmaceutical pollutants, nitrogen fixation, photocatalytic hydrogen evolution, and carbon dioxide conversion, among others. High electrical conductivity, robust photothermal effects, large surface area, hydrophilicity, and abundant surface functional groups of MXenes render them as attractive candidates for photocatalytic removal of pollutants as well as improvement of photocatalytic performance of semiconductor catalysts. Herein, the most recent developments in photocatalytic degradation of organic and pharmaceutical pollutants using MXene-based composites are deliberated, with a focus on important challenges and future perspectives; techniques for fabrication of these photocatalysts are also covered.

Advanced Drug Delivery Micro- and Nanosystems for Cardiovascular Diseases.

Advanced drug delivery micro- and nanosystems have been widely explored due to their appealing specificity/selectivity, biodegradability, biocompatibility, and low toxicity. They can be applied for the targeted delivery of pharmaceuticals, with the benefits of good biocompatibility/stability, non-immunogenicity, large surface area, high drug loading capacity, and low leakage of drugs. Cardiovascular diseases, as one of the primary mortalities cause worldwide with significant impacts on the quality of patients' life, comprise a variety of heart and circulatory system pathologies, such as peripheral vascular diseases, myocardial infarction, heart failure, and coronary artery diseases. Designing novel micro- and nanosystems with suitable targeting properties and smart release behaviors can help circumvent crucial challenges of the tolerability, low stability, high toxicity, and possible side- and off-target effects of conventional drug delivery routes. To overcome different challenging issues, namely physiological barriers, low efficiency of drugs, and possible adverse side effects, various biomaterials-mediated drug delivery systems have been formulated with reduced toxicity, improved pharmacokinetics, high bioavailability, sustained release behavior, and enhanced therapeutic efficacy for targeted therapy of cardiovascular diseases. Despite the existing drug delivery systems encompassing a variety of biomaterials for treating cardiovascular diseases, the number of formulations currently approved for clinical use is limited due to the regulatory and experimental obstacles. Herein, the most recent advancements in drug delivery micro- and nanosystems designed from different biomaterials for the treatment of cardiovascular diseases are deliberated, with a focus on the important challenges and future perspectives.

Biowaste-Derived Carbon Dots: A Perspective on Biomedical Potentials.

Today, sustainable and natural resources including biowastes have been considered attractive starting materials for the fabrication of biocompatible and biodegradable carbon dots (CDs) due to the benefits of availability, low cost, biorenewability, and environmentally benign attributes. These carbonaceous nanomaterials have been widely explored in the field of sensing/imaging, optoelectronics, photocatalysis, drug/gene delivery, tissue engineering, regenerative medicine, and cancer theranostics. Designing multifunctional biowaste-derived CDs with a high efficacy-to-toxicity ratio for sustained and targeted drug delivery, along with imaging potentials, opens a new window of opportunity toward theranostic applications. However, crucial challenges regarding the absorption/emission wavelength, up-conversion emission/multiphoton fluorescence mechanisms, and phosphorescence of these CDs still need to be addressed to attain the maximum functionality and efficacy. Future studies ought to focus on optimizing the synthesis techniques/conditions, evaluating the influence of nucleation/growth process on structures/properties, controlling their morphology/size, and finding the photoluminescence mechanisms. Reproducibility of synthesis techniques is another critically important factor that needs to be addressed in the future. Herein, the recent developments related to the biowaste-derived CDs with respect to their biomedical applications are deliberated, focusing on important challenges and future perspectives.

Molecularly imprinted polymers for the detection of viruses: challenges and opportunities.

Molecularly imprinted polymers (MIPs) have numerous applications in the sensing field, the detection/recognition of virus, the structure determination of proteins, drug delivery, artificial/biomimetic antibodies, drug discovery, and cell culturing. There are lots of conventional methods routinely deployed for the analysis/detection of viral infections and pathogenic viruses, namely enzyme immunoassays, immunofluorescence microscopy, polymerase chain reaction (PCR) and virus isolation. However, they typically suffer from higher costs, low selectivity/specificity, false negative/positive results, time consuming procedures, and inherent labor intensiveness. MIPs offer promising potential for viral recognition/detection with high target selectivity, sensitivity, robustness, reusability, and reproducible fabrication. In terms of virus detection, selectivity and sensitivity are critical parameters determined by the template; additionally, the analytical detection and evaluation of viruses must have considerably low detection limits. The virus-imprinted polymer-based innovative strategies with enough specificity, convenience, validity, and reusability features for the detection/recognition of a wide variety of viruses, can provide attractive capabilities for reliable screening with minimal false negative/positive results that is so crucial for the prevention and control of epidemic and pandemic viral infections. However, in the process of imprinting viruses, critical factors such as size of the target, solubility, fragility, and compositional complexity should be analytically considered and systematically evaluated. In this review, recent advancements regarding the applications of MIPs and pertinent virus imprinting techniques for the detection of viruses, as well as their current significant challenges and future perspectives, are deliberated.

Leishmanicidal activities of biosynthesized BaCO3 (witherite) nanoparticles and their biocompatibility with macrophages.

The aim of this study was cost-effective and greener synthesis of barium carbonate (BaCO3 or witherite) nanoparticles with economic importance, and to evaluate their therapeutic potentials and biocompatibility with immune cells. Barium carbonate nanoparticles were biosynthesized using black elderberry extract in one step with non-toxic precursors and simple laboratory conditions; their morphologies and specific structures were analyzed using field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX). The therapeutic capabilities of these nanoparticles on the immune cells of murine macrophages J774 and promastigotes Leishmania tropica were evaluated. BaCO3 nanoparticles with IC50 = 46.6 µg/mL were more effective than negative control and glucantium (positive control) in reducing promastigotes (P < 0.01). Additionally, these nanoparticles with a high value of cytotoxicity concentration 50% (CC50) were less toxic to macrophage cells than glucantime; however, they were significantly different at high concentrations compared to the negative control.

Green synthesis, biomedical and biotechnological applications of carbon and graphene quantum dots. A review.

Carbon and graphene quantum dots are prepared using top-down and bottom-up methods. Sustainable synthesis of quantum dots has several advantages such as the use of low-cost and non-toxic raw materials, simple operations, expeditious reactions, renewable resources and straightforward post-processing steps. These nanomaterials are promising for clinical and biomedical sciences, especially in bioimaging, diagnosis, bioanalytical assays and biosensors. Here we review green methods for the fabrication of quantum dots, and biomedical and biotechnological applications.