Injectable hydrogels based on biopolymers for the treatment of ocular diseases.

Injectable hydrogels based on biopolymers, fabricated utilizing diverse chemical and physical methodologies, exhibit exceptional physical, chemical, and biological properties. They have multifaceted applications encompassing wound healing, tissue regeneration, and across diverse scientific realms. This review critically evaluates their largely uncharted potential in ophthalmology, elucidating their diverse applications across an array of ocular diseases. These conditions include glaucoma, cataracts, corneal disorders (spanning from age-related degeneration to trauma, infections, and underlying chronic illnesses), retina-associated ailments (such as diabetic retinopathy, retinitis pigmentosa, and age-related macular degeneration (AMD)), eyelid abnormalities, and uveal melanoma (UM). This study provides a thorough analysis of applications of injectable hydrogels based on biopolymers across these ocular disorders. Injectable hydrogels based on biopolymers can be customized to have specific physical, chemical, and biological properties that make them suitable as drug delivery vehicles, tissue scaffolds, and sealants in the eye. For example, they can be engineered to have optimum viscosity to be injected intravitreally and sustain drug release to treat retinal diseases. Their porous structure and biocompatibility promote cellular infiltration to regenerate diseased corneal tissue. By accentuating their indispensable role in ocular disease treatment, this review strives to present innovative and targeted approaches in this domain, thereby advancing ocular therapeutics.

Chitosan-based nanosystems for cancer diagnosis and therapy: Stimuli-responsive, immune response, and clinical studies.

Cancer, a global health challenge of utmost severity, necessitates innovative approaches beyond conventional treatments (e.g., surgery, chemotherapy, and radiation therapy). Unfortunately, these approaches frequently fail to achieve comprehensive cancer control, characterized by inefficacy, non-specific drug distribution, and the emergence of adverse side effects. Nanoscale systems based on natural polymers like chitosan have garnered significant attention as promising platforms for cancer diagnosis and therapy owing to chitosan's inherent biocompatibility, biodegradability, nontoxicity, and ease of functionalization. Herein, recent advancements pertaining to the applications of chitosan nanoparticles in cancer imaging and drug/gene delivery are deliberated. The readers are introduced to conventional non-stimuli-responsive and stimuli-responsive chitosan-based nanoplatforms. External triggers like light, heat, and ultrasound and internal stimuli such as pH and redox gradients are highlighted. The utilization of chitosan nanomaterials as contrast agents or scaffolds for multimodal imaging techniques e.g., magnetic resonance, fluorescence, and nuclear imaging is represented. Key applications in targeted chemotherapy, combination therapy, photothermal therapy, and nucleic acid delivery using chitosan nanoformulations are explored for cancer treatment. The immunomodulatory effects of chitosan and its role in impacting the tumor microenvironment are analyzed. Finally, challenges, prospects, and future outlooks regarding the use of chitosan-based nanosystems are discussed.

A strategy for As(III) determination based on ultrafine gold nanoparticles decorated on magnetic graphene oxide.

In this work, a new dendrimer modified magnetic graphene oxide (GO) was used as a substrate for electrodeposition of Au nanoparticles. The modified magnetic electrode was employed for sensitive measuring of As(III) ion as a well-established human carcinogen. The prepared electrochemical device exhibits excellent activity towards As(III) detection using the square wave anodic stripping voltammetry (SWASV) protocol. At optimum conditions (deposition potential at -0.5 V for 100 s in 0.1 M acetate buffer with pH 5.0), a linear range from 1.0 to 125.0 µgL-1 with a low detection limit (calculated by S/N = 3) of 0.47 µg L-1 was obtained. In addition to the simplicity and sensitivity of the proposed sensor, its high selectivity against some major interfering agents, such as Cu(II) and Hg(II) makes it an appreciable sensing tool for the screening of As(III). In addition, the sensor revealed satisfactory results for detection of As(III) in different water samples, and the accuracy of obtained data were confirmed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) setup. Accounting for the high sensitivity, remarkable selectivity and good reproducibility, the established electrochemical strategy has great potential for analysis of As(III) in environmental matrices.

Magnetic poly(1,8-diaminonaphthalene)-nickel nanocatalyst for the synthesis of antioxidant and antibacterial isoxazole-5(4H)-ones derivatives.

A magnetic poly (1,8-diaminonaphthalene)-nickel (PDAN-Ni@Fe3O4) composite as a multifunctional nanocatalyst was prepared in several steps including (I) synthesis of poly (1,8-diaminonaphthalene) (PDAN), (II) modification of PDAN with NiSO4 (PDAN-Ni) and (III) preparation of magnetic nanocatalyst by iron (I and II) salts in the existence of PDAN-Ni complex (PDAN-Ni@Fe3O4). Fourier-transform infrared spectroscopy (FTIR), elemental analysis (CHNSO), vibrating-sample magnetometer (VSM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), field emission scanning electron microscope (FESEM), ultraviolet-visible (UV-vis), and thermogravimetric analysis (TGA) were applied to characterize the prepared nanocatalyst. The PDAN-Ni@Fe3O4 was applied as an environmentally friendly nanocatalyst for the isoxazole-5(4H)-ones synthesis via a one-pot reaction between aryl/heteroaryl aldehyde, hydroxylamine hydrochloride, and ß-ketoester. The nanocomposite was also used for the synthesis of some new alkylene bridging bis 4-benzylidene-3-methyl isoxazole-5(4H)-ones. The catalyst's reusability, and the antioxidant and antibacterial activities of both catalyst and products, were studied. Results showed that the nanocatalyst and isoxazole-5(4H)-ones have antioxidant activity of 75% and 92%, respectively. In addition, the antibacterial test showed that the nanocatalyst and isoxazole-5(4H)-ones have highly active versus Staphylococcus aureus and Escherichia coli bacteria. The reusability and stability of the nanocatalyst, a medium to higher product yield and conversion, a faster reaction time, and the use of green solvents were a few benefits of this study.

Engineering and Development of a Tissue Model for the Evaluation of Microneedle Penetration Ability, Drug Diffusion, Photothermal Activity, and Ultrasound Imaging: A Promising Surrogate to Ex Vivo and In Vivo Tissues.

Driven by regulatory authorities and the ever-growing demands from industry, various artificial tissue models have been developed. Nevertheless, there is no model to date that is capable of mimicking the biomechanical properties of the skin whilst exhibiting the hydrophilicity/hydrophobicity properties of the skin layers. As a proof-of-concept study, tissue surrogates based on gel and silicone are fabricated for the evaluation of microneedle penetration, drug diffusion, photothermal activity, and ultrasound bioimaging. The silicone layer aims to imitate the stratum corneum while the gel layer aims to mimic the water-rich viable epidermis and dermis present in in vivo tissues. The diffusion of drugs across the tissue model is assessed, and the results reveal that the proposed tissue model shows similar behavior to a cancerous kidney. In place of typical in vitro aqueous solutions, this model can also be employed for evaluating the photoactivity of photothermal agents since the tissue model shows a similar heating profile to skin of mice when irradiated with near-infrared laser. In addition, the designed tissue model exhibits promising results for biomedical applications in optical coherence tomography and ultrasound imaging. Such a tissue model paves the way to reduce the use of animals testing in research whilst obviating ethical concerns.

Carbohydrate polymer-based nanocomposites for breast cancer treatment.

Breast cancer is known as the most common invasive malignancy in women with the highest mortality rate worldwide. This concerning disease may be presented in situ (relatively easier treatment) or be invasive, especially invasive ductal carcinoma which is highly worrisome nowadays. Among several strategies used in breast cancer treatment, nanotechnology-based targeted therapy is currently being investigated, as it depicts advanced technological features able of preventing drugs' side effects on normal cells while effectively acting on tumor cells. In this context, carbohydrate polymer-based nanocomposites have gained particular interest among the biomedical community for breast cancer therapy applications due to their advantage features, including abundance in nature, biocompatibility, straightforward fabrication methods, and good physicochemical properties. In this review, the physicochemical properties and biological activities of carbohydrate polymers and their derivate nanocomposites were discussed. Then, various methods for the fabrication of carbohydrate polymer-based nanocomposites as well as their application in breast cancer therapy and future perspectives were discussed.

A review on the effectiveness of nanocomposites for the treatment and recovery of oil spill.

The introduction of unintended oil spills into the marine ecosystem has a significant impact on aquatic life and raises important environmental concerns. The present review summarizes the recent studies where nanocomposites are applied to treat oil spills. The review deals with the techniques used to fabricate nanocomposites and identify the characteristics of nanocomposites beneficial for efficient recovery and treatment of oil spills. It classifies the nanocomposites into four categories, namely bio-based materials, polymeric materials, inorganic-inorganic nanocomposites, and carbon-based nanocomposites, and provides an insight into understanding the interactions of these nanocomposites with different types of oils. Among nanocomposites, bio-based nanocomposites are the most cost-effective and environmentally friendly. The grafting or modification of magnetic nanoparticles with polymers or other organic materials is preferred to avoid oxidation in wet conditions. The method of synthesizing magnetic nanocomposites and functionalization polymer is essential as it influences saturation magnetization. Notably, the inorganic polymer-based nanocomposite is very less developed and studied for oil spill treatment. Also, the review covers some practical considerations for treating oil spills with nanocomposites. Finally, some aspects of future developments are discussed. The terms "Environmentally friendly," "cost-effective," and "low cost" are often used, but most of the studies lack a critical analysis of the cost and environmental damage caused by chemical alteration techniques. However, the oil and gas industry will considerably benefit from the stimulation of ideas and scientific discoveries in this field.

Stimuli-responsive liposomal nanoformulations in cancer therapy: Pre-clinical & clinical approaches.

The site-specific delivery of antitumor agents is of importance for providing effective cancer suppression. Poor bioavailability of anticancer compounds and the presence of biological barriers prevent their accumulation in tumor sites. These obstacles can be overcome using liposomal nanostructures. The challenges in cancer chemotherapy and stimuli-responsive nanocarriers are first described in the current review. Then, stimuli-responsive liposomes including pH-, redox-, enzyme-, light-, thermo- and magneto-sensitive nanoparticles are discussed and their potential for delivery of anticancer drugs is emphasized. The pH- or redox-sensitive liposomes are based on internal stimulus and release drug in response to a mildly acidic pH and GSH, respectively. The pH-sensitive liposomes can mediate endosomal escape via proton sponge. The multifunctional liposomes responsive to both redox and pH have more capacity in drug release at tumor site compared to pH- or redox-sensitive alone. The magnetic field and NIR irradiation can be exploited for external stimulation of liposomes. The light-responsive liposomes release drugs when they are exposed to irradiation; thermosensitive-liposomes release drugs at a temperature of >40 °C when there is hyperthermia; magneto-responsive liposomes release drugs in presence of magnetic field. These smart nanoliposomes also mediate co-delivery of drugs and genes in synergistic cancer therapy. Due to lack of long-term toxicity of liposomes, they can be utilized in near future for treatment of cancer patients.

Macrophage Cell Membrane-Cloaked Nanoplatforms for Biomedical Applications.

Biomimetic approaches utilize natural cell membrane-derived nanovesicles to camouflage nanoparticles to circumvent some limitations of nanoscale materials. This emergent cell membrane-coating technology is inspired by naturally occurring intercellular interactions, to efficiently guide nanostructures to the desired locations, thereby increasing both therapeutic efficacy and safety. In addition, the intrinsic biocompatibility of cell membranes allows the crossing of biological barriers and avoids elimination by the immune system. This results in enhanced blood circulation time and lower toxicity in vivo. Macrophages are the major phagocytic cells of the innate immune system. They are equipped with a complex repertoire of surface receptors, enabling them to respond to biological signals, and to exhibit a natural tropism to inflammatory sites and tumorous tissues. Macrophage cell membrane-functionalized nanosystems are designed to combine the advantages of both macrophages and nanomaterials, improving the ability of those nanosystems to reach target sites. Recent studies have demonstrated the potential of these biomimetic nanosystems for targeted delivery of drugs and imaging agents to tumors, inflammatory, and infected sites. The present review covers the preparation and biomedical applications of macrophage cell membrane-coated nanosystems. Challenges and future perspectives in the development of these membrane-coated nanosystems are addressed.

Iron-based metal-organic framework: Synthesis, structure and current technologies for water reclamation with deep insight into framework integrity.

Water is a supreme requirement for the existence of life, the contamination from the point and non-point sources are creating a great threat to the water ecosystem. Advance tools and techniques are required to restore the water quality and metal-organic framework (MOFs) with a tunable porous structure, striking physical and chemical properties are an excellent candidate for it. Fe-based MOFs, which developed rapidly in recent years, are foreseen as most promising to overcome the disadvantages of traditional water depolluting practices. Fe-MOFs with low toxicity and preferable stability possess excellent performance potential for almost all water remedying techniques in contrast to other MOF structures, especially visible light photocatalysis, Fenton, and Fenton-like heterogeneous catalysis. Fe-MOFs become essential tool for water treatment due to their high catalytic activity, abundant active site and pollutant-specific adsorption. However, the structural degradation under external chemical, photolytic, mechanical, and thermal stimuli is impeding Fe-MOFs from further improvement in activity and their commercialization. Understanding the shortcomings of structural integrity is crucial for large-scale synthesis and commercial implementation of Fe-MOFs-based water treatment techniques. Herein we summarize the synthesis, structure and recent advancements in water remediation methods using Fe-MOFs in particular more attention is paid for adsorption, heterogeneous catalysis and photocatalysis with clear insight into the mechanisms involved. For ease of analysis, the pollutants have been classified into two major classes; inorganic pollutants and organic pollutants. In this review, we present for the first time a detailed insight into the challenges in employing Fe-MOFs for water remediation due to structural instability.

An overview on non-spherical semiconductors for heterogeneous photocatalytic degradation of organic water contaminants.

Because of their carcinogenicity and mutagenicity, the elimination of organic contaminants from surface and subsurface water is a subject of environmental significance. Conventional water decontamination approaches such as membrane separation, ultrafiltration, adsorption, reverse osmosis, coagulation, etc., have relatively higher operating costs and can generate highly toxic secondary contaminants. On the other hand, heterogeneous photocatalysis, an advanced oxidation process (AOP), is considered a clean and cost-effective process for organic pollutants degradation. Owing to their distinctive structure and physicochemical properties non-spherical semiconductors have gained considerable limelight in the photocatalytic degradation of organic contaminants. The current review briefly introduces a wide range of organic water contaminants. Recent advances in non-spherical semiconductor assembly and their photocatalytic degradation applications are highlighted. The underlying mechanism, fundamentals of photocatalytic reactions, and the factors affecting the degradation performance are also alluded including the current challenges and future research perspectives.

Toxicity and remediation of pharmaceuticals and pesticides using metal oxides and carbon nanomaterials.

The worldwide development of agriculture and industry has resulted in contamination of water bodies by pharmaceuticals, pesticides and other xenobiotics. Even at trace levels of few micrograms per liter in waters, these contaminants induce public health and environmental issues, thus calling for efficient removal methods such as adsorption. Recent adsorption techniques for wastewater treatment involve metal oxide compounds, e.g. Fe2O3, ZnO, Al2O3 and ZnO-MgO, and carbon-based materials such as graphene oxide, activated carbon, carbon nanotubes, and carbon/graphene quantum dots. Here, the small size of metal oxides and the presence various functional groups has allowed higher adsorption efficiencies. Moreover, carbon-based adsorbents exhibit unique properties such as high surface area, high porosity, easy functionalization, low price, and high surface reactivity. Here we review the cytotoxic effects of pharmaceutical drugs and pesticides in terms of human risk and ecotoxicology. We also present remediation techniques involving adsorption on metal oxides and carbon-based materials.

Drug Delivery (Nano)Platforms for Oral and Dental Applications: Tissue Regeneration, Infection Control, and Cancer Management.

The oral cavity and oropharynx are complex environments that are susceptible to physical, chemical, and microbiological insults. They are also common sites for pathological and cancerous changes. The effectiveness of conventional locally-administered medications against diseases affecting these oral milieus may be compromised by constant salivary flow. For systemically-administered medications, drug resistance and adverse side-effects are issues that need to be resolved. New strategies for drug delivery have been investigated over the last decade to overcome these obstacles. Synthesis of nanoparticle-containing agents that promote healing represents a quantum leap in ensuring safe, efficient drug delivery to the affected tissues. Micro/nanoencapsulants with unique structures and properties function as more favorable drug-release platforms than conventional treatment approaches. The present review provides an overview of newly-developed nanocarriers and discusses their potential applications and limitations in various fields of dentistry and oral medicine.

Nonspherical Metal-Based Nanoarchitectures: Synthesis and Impact of Size, Shape, and Composition on Their Biological Activity.

Metal-based nanoentities, apart from being indispensable research tools, have found extensive use in the industrial and biomedical arena. Because their biological impacts are governed by factors such as size, shape, and composition, such issues must be taken into account when these materials are incorporated into multi-component ensembles for clinical applications. The size and shape (rods, wires, sheets, tubes, and cages) of metallic nanostructures influence cell viability by virtue of their varied geometry and physicochemical interactions with mammalian cell membranes. The anisotropic properties of nonspherical metal-based nanoarchitectures render them exciting candidates for biomedical applications. Here, the size-, shape-, and composition-dependent properties of nonspherical metal-based nanoarchitectures are reviewed in the context of their potential applications in cancer diagnostics and therapeutics, as well as, in regenerative medicine. Strategies for the synthesis of nonspherical metal-based nanoarchitectures and their cytotoxicity and immunological profiles are also comprehensively appraised.

Progress in Delivery of siRNA-Based Therapeutics Employing Nano-Vehicles for Treatment of Prostate Cancer.

Prostate cancer (PCa) accounts for a high number of deaths in males with no available curative treatments. Patients with PCa are commonly diagnosed in advanced stages due to the lack of symptoms in the early stages. Recently, the research focus was directed toward gene editing in cancer therapy. Small interfering RNA (siRNA) intervention is considered as a powerful tool for gene silencing (knockdown), enabling the suppression of oncogene factors in cancer. This strategy is applied to the treatment of various cancers including PCa. The siRNA can inhibit proliferation and invasion of PCa cells and is able to promote the anti-tumor activity of chemotherapeutic agents. However, the off-target effects of siRNA therapy remarkably reduce its efficacy in PCa therapy. To date, various carriers were designed to improve the delivery of siRNA and, among them, nanoparticles are of importance. Nanoparticles enable the targeted delivery of siRNAs and enhance their potential in the downregulation of target genes of interest. Additionally, nanoparticles can provide a platform for the co-delivery of siRNAs and anti-tumor drugs, resulting in decreased growth and migration of PCa cells. The efficacy, specificity, and delivery of siRNAs are comprehensively discussed in this review to direct further studies toward using siRNAs and their nanoscale-delivery systems in PCa therapy and perhaps other cancer types.

Antibacterial tragacanth gum-based nanocomposite films carrying ascorbic acid antioxidant for bioactive food packaging.

Food packaging has a pivotal share to improve protection, safety and shelf-life time of foods and bioproducts. Herein, we prepared bioactive nanocomposite films that composed of tragacanth (TG), polyvinyl alcohol, ZnO nanoparticles (NPs) and ascorbic acid (AA) using glycerol as a plasticizer and citric acid as a cross-linker for food packaging. The SEM images showed a homogenous distribution of ZnO NPs with low aggregation in nanocomposite films. The water solubility of nanocomposite films reduced from 15.65 % to 10.81 with increasing of TG and ZnO NPs contents. The incorporation of AA and ZnO NPs into nanocomposite films improved antioxidant activity from 50 % to 66 % in 95 % ethanolic solution. Also, the nanocomposite films showed good antibacterial activity against Gram-negative and -positive bacteria. Soil degradation rate of nanocomposite films increased from 80 % to 91.46 as the wt% of TG increased. Therefore, prepared nanocomposite films could be employed as a promising candidate for food packaging applications.

Progress in Conductive Polyaniline-Based Nanocomposites for Biomedical Applications: A Review.

Inherently conducting polymers (ICPs) are a specific category of synthetic polymers with distinctive electro-optic properties, which involve conjugated chains with alternating single and double bonds. Polyaniline (PANI), as one of the most well-known ICPs, has outstanding potential applications in biomedicine because of its high electrical conductivity and biocompatibility caused by its hydrophilic nature, low-toxicity, good environmental stability, and nanostructured morphology. Some of the limitations in the use of PANI, such as its low processability and degradability, can be overcome by the preparation of its blends and nanocomposites with various (bio)polymers and nanomaterials, respectively. This review describes the state-of-the-art of biological activities and applications of conductive PANI-based nanocomposites in the biomedical fields, such as antimicrobial therapy, drug delivery, biosensors, nerve regeneration, and tissue engineering. The latest progresses in the biomedical applications of PANI-based nanocomposites are reviewed to provide a background for future research.