A Comprehensive Review on the Synthesis, Characterization, and Biomedical Application of Platinum Nanoparticles

Prunella vulgaris-phytosynthesized platinum nanoparticles: Insights into nanozymatic activity for H2O2 and glutamate detection and antioxidant capacity

Artificial nanozymes (enzyme-mimics), specifically metallic nanomaterials, have garnered significant attention recently due to their reduced preparation cost and enhanced stability in a wide range of environments. The present investigation highlights, for the first time, a straightforward green synthesis of biogenic platinum nanoparticles (PtNPs) from a natural resource, namely Prunella vulgaris (Pr). To demonstrate the effectiveness of the phytochemical extract as an effective reducing agent, the PtNPs were characterized by various techniques such as UV-vis spectroscopy, High-resolution Transmission electron microscopy (HR-TEM), zeta-potential analysis, Fourier-transform infrared spectroscopy (FTIR), and Energy dispersive spectroscopy (EDS). The formation of PtNPs with narrow size distribution was verified. Surface decoration of PtNPs was demonstrated with multitudinous functional groups springing from the herbal extract. To demonstrate their use as viable nanozymes, the peroxidase-like activity of Pr/PtNPs was evaluated through a colorimetric assay. Highly sensitive visual detection of H2O2 with discrete linear ranges and a low detection limit of 3.43 μM was demonstrated. Additionally, peroxidase-like catalytic activity was leveraged to develop a colorimetric platform to quantify glutamate biomarker levels with a high degree of selectivity, the limit of detection (LOD) being 7.00 μM. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) test was used to explore the scavenging nature of the PtNPs via the degradation of DPPH. Overall, the colorimetric assay developed using the Pr/PtNP nanozymes in this work could be used in a broad spectrum of applications, ranging from biomedicine and food science to environmental monitoring.

Current development of theragnostic nanoparticles for women's cancer treatment

In the biomedical industry, nanoparticles (NPs-exclusively small particles with size ranging from 1-100 nanometres) are recently employed as powerful tools due to their huge potential in sophisticated and enhanced cancer theragnostic (i.e. therapeutics and diagnostics). Cancer is a life-threatening disease caused by carcinogenic agents and mutation in cells, leading to uncontrolled cell growth and harming the body's normal functioning while affecting several factors like low levels of reactive oxygen species, hyperactive antiapoptotic mRNA expression, reduced proapoptotic mRNA expression, damaged DNA repair, and so on. NPs are extensively used in early cancer diagnosis and are functionalized to target receptors overexpressing cancer cells for effective cancer treatment. This review focuses explicitly on how NPs alone and combined with imaging techniques and advanced treatment techniques have been researched against 'women's cancer' such as breast, ovarian, and cervical cancer which are substantially occurring in women. NPs, in combination with numerous imaging techniques (like PET, SPECT, MRI, etc) have been widely explored for cancer imaging and understanding tumor characteristics. Moreover, NPs in combination with various advanced cancer therapeutics (like magnetic hyperthermia, pH responsiveness, photothermal therapy, etc), have been stated to be more targeted and effective therapeutic strategies with negligible side effects. Furthermore, this review will further help to improve treatment outcomes and patient quality of life based on the theragnostic application-based studies of NPs in women's cancer treatment.

Chitosan nanoparticle applications in dentistry: a sustainable biopolymer

The epoch of Nano-biomaterials and their application in the field of medicine and dentistry has been long-lived. The application of nanotechnology is extensively used in diagnosis and treatment aspects of oral diseases. The nanomaterials and its structures are being widely involved in the production of medicines and drugs used for the treatment of oral diseases like periodontitis, oral carcinoma, etc. and helps in maintaining the longevity of oral health. Chitosan is a naturally occurring biopolymer derived from chitin which is seen commonly in arthropods. Chitosan nanoparticles are the latest in the trend of nanoparticles used in dentistry and are becoming the most wanted biopolymer for use toward therapeutic interventions. Literature search has also shown that chitosan nanoparticles have anti-tumor effects. This review highlights the various aspects of chitosan nanoparticles and their implications in dentistry.

Bio synthesis, comprehensive characterization, and multifaceted therapeutic applications of BSA-Resveratrol coated platinum nanoparticles

This study examines the manufacturing, characterization, and biological evaluation of platinum nanoparticles, which were synthesized by Enterobacter cloacae and coated with Bovine Serum Albumin (BSA) and Resveratrol (RSV). The formation of PtNPs was confirmed with the change of color from dark yellow to black, which was due to the bioreduction of platinum chloride by E. cloacae. BSA and RSV functionalization enhanced these nanoparticles' biocompatibility and therapeutic potential. TGA, SEM, XRD, and FTIR were employed for characterization, where PtNPs and drug conjugation-related functional groups were studied by FTIR. XRD confirmed the crystalline nature of PtNPs and Pt-BSA-RSV NPs, while TGA and SEM showed thermal stability and post-drug coating morphological changes. Designed composite was also found to be biocompatible in nature in hemolytic testing, indicating their potential in Biomedical applications. After confirmation of PtNPs based nanocaompsite synthesis, they were examined for anti-bacterial, anti-oxidant, anti-inflammatory, and anti-cancer properties. Pt-BSA-RSV NPs showed higher concentration-dependent DPPH scavenging activity, which measured antioxidant capability. Enzyme inhibition tests demonstrated considerable anti-inflammatory activity against COX-2 and 15-LOX enzymes. In in vitro anticancer studies, Pt-BSA-RSV NPs effectively killed human ovarian cancer cells. This phenomenon was demonstrated to be facilitated by the acidic environment of cancer, as the drug release assay confirmed the release of RSV from the NP formulation in the acidic environment. Finally, Molecular docking also demonstrated that RSV has strong potential as an anti-oxidant, antibacterial, anti-inflammatory, and anticancer agent. Overall, in silico and in vitro investigations in the current study showed good medicinal applications for designed nanocomposites, however, further in-vivo experiments must be conducted to validate our findings.

Nanosynthesis, phycochemical constituents, and pharmacological properties of cyanobacterium Oscillatoria sp

The Oscillatoria sp., a blue-green alga or cyanobacterium, consists of about 305 species distributed globally. Cyanobacteria are prokaryotes possessing several secondary metabolites that have industrial and biomedical applications. Particularly, the published reviews on Oscillatoria sp. have not recorded any pharmacology, or possible details, while the detailed chemical structures of the alga are reported in the literature. Hence, this study considers pertinent pharmacological activities of the plethora of bioactive components of Oscillatoria sp. Furthermore, the metallic nanoparticles produced with Oscillatoria sp. were documented for plausible antibacterial, antifungal, antioxidant, anticancer, and cytotoxic effects against several cultured human cell lines. The antimicrobial activities of solvent extracts of Oscillatoria sp. and the biotic activities of its derivatives, pyridine, acridine, fatty acids, and triazine were structurally described in detail. To understand the connotations with research gaps and provide some pertinent prospective suggestions for further research on cyanobacteria as potent sources of pharmaceutical utilities, attempts were documented. The compounds of Oscillatoria sp. are a potent source of secondary metabolites that inhibit the cancer cell lines, in vitro. It could be expected that by holistic exploitation, the natural Oscillatoria products, as the source of chemical varieties and comparatively more potent inhibitors, would be explored against pharmacological activities with the integument of SARs.

Designing Gold Nanoparticles for Precise Glioma Treatment: Challenges and Alternatives

Glioblastoma multiforme (GBM) is a glioma and the most aggressive type of brain tumor with a dismal average survival time, despite the standard of care. One promising alternative therapy is boron neutron capture therapy (BNCT), which is a noninvasive therapy for treating locally invasive malignant tumors, such as glioma. BNCT involves boron-10 isotope capturing neutrons to form boron-11, which then releases radiation directly into tumor cells with minimal damage to healthy tissues. This therapy lacks clinically approved targeted blood-brain-barrier-permeating delivery vehicles for the central nervous system (CNS) entry of therapeutic boron-10. Gold nanoparticles (GNPs) are selective and effective drug-delivery vehicles because of their desirable properties, facile synthesis, and biocompatibility. This review discusses biomedical/therapeutic applications of GNPs as a drug delivery vehicle, with an emphasis on their potential for carrying therapeutic drugs, imaging agents, and GBM-targeting antibodies/peptides for treating glioma. The constraints of GNP therapeutic efficacy and biosafety are discussed.

Recent Developments of Nano Flame Retardants for Unsaturated Polyester Resin

For many years, efforts have been made to reduce the flammability of unsaturated polyester resins (UPRs), which are often used in the rail, shipbuilding, and construction industries. Without modification, they often fail to meet fire safety standards. Despite a rich history of flame retardants (FRs) applied to UPRs, researchers seek new solutions that will provide lower flammability and smoke density, as well as attaining a lower environmental impact from the composites. The objective of the study is to highlight the most important recent research on promising nano FRs in order to promote their further development. Mechanisms of action of several groups of nano FRs, such as clay-based, carbon-based, transition metal compounds, layered double hydroxides, polyhedral oligomeric silsesquioxanes, and others, including bio-based, have been studied. Particular emphasis has been laid on nano FRs applied to UPRs, and their influences on thermal stability, flammability, and mechanical properties. Moreover, the environmental impact and toxicity of nano FRs have been discussed. Results have proved that nano FRs applied at low loadings may significantly improve thermal stability, with a simultaneous increase or only a slight decrease in mechanical properties. However, attention on related environmental issues has highlighted the necessity of carefully selecting novel nano FRs.

Zebrafish Insights into Nanomaterial Toxicity: A Focused Exploration on Metallic, Metal Oxide, Semiconductor, and Mixed-Metal Nanoparticles

Nanomaterials are widely used in various fields, and ongoing research is focused on developing safe and sustainable nanomaterials. Using zebrafish as a model organism for studying the potentially toxic effects of nanomaterials highlights the importance of developing safe and sustainable nanomaterials. Studies conducted on nanomaterials and their toxicity and potential risks to human and environmental health are vital in biomedical sciences. In the present review, we discuss the potential toxicity of nanomaterials (inorganic and organic) and exposure risks based on size, shape, and concentration. The review further explores various types of nanomaterials and their impacts on zebrafish at different levels, indicating that exposure to nanomaterials can lead to developmental defects, changes in gene expressions, and various toxicities. The review also covers the importance of considering natural organic matter and chorion membranes in standardized nanotoxicity testing. While some nanomaterials are biologically compatible, metal and semiconductor nanomaterials that enter the water environment can increase toxicity to aquatic creatures and can potentially accumulate in the human body. Further investigations are necessary to assess the safety of nanomaterials and their impacts on the environment and human health.

Catalytic and anti-cancer properties of platinum, gold, silver, and bimetallic Au-Ag nanoparticles synthesized by Bacillus sp. bacteria

Metallic nanoparticles play a significant role in the catalysis of chemical processes, besides, bimetallic nanoparticles with abundant active sites can reduce metallic nanoparticles toxicity in addition to increasing their catalytic performances. In this work, the platinum, gold, and silver nanoparticles are bio-synthesized using a native bacterium (GFCr-4). Also, the Au-Ag and Au@Ag bimetallic nanoparticles with alloy and core-shell structures, respectively, are biologically synthesized. To improve the synthesis, the effects of various factors like pH, temperature, electron donor, and ionic liquids were investigated. The as-synthesized nanoparticles were characterized with different techniques. The microscope images and dynamic light scattering (DLS) analysis confirm the uniform distribution of as-synthesized nanoparticles with average sizes of 25, 30, 47, 77, and 86 nm obtained for Ag, Au, Pt, Au-Ag alloy, and Au@Ag core-shell, respectively. The catalytic performances of as-synthesized nanoparticles were investigated. The Au-Ag alloy nanoparticles exhibit better catalytic performance than the as-synthesized metallic Au nanoparticles, according to the Gewald reaction. According to the photocatalytic study, the yield can be increased by up to 92% by using PtNPs in the presence of a green LED. Additionally, for the first time, PtNPs were utilized as an effective catalyst in a peroxyoxalate chemiluminescence (POCL) system in the presence of nuclear fast red (NFR) as a novel fluorophore. In addition, the results of the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay revealed that the synthesized eco-friendly nanoparticles have a low effect on the lethality of 3T3 normal cells whereas MCF-7 cancer cells were inhibited up to 77.3% after treatment by PtNPs nanoparticles.

Advancement in nanomaterials for environmental pollutants remediation: a systematic review on bibliometrics analysis, material types, synthesis pathways, and related mechanisms

Environmental pollution is a major issue that requires effective solutions. Nanomaterials (NMs) have emerged as promising candidates for pollution remediation due to their unique properties. This review paper provides a systematic analysis of the potential of NMs for environmental pollution remediation compared to conventional techniques. It elaborates on several aspects, including conventional and advanced techniques for removing pollutants, classification of NMs (organic, inorganic, and composite base). The efficiency of NMs in remediation of pollutants depends on their dispersion and retention, with each type of NM having different advantages and disadvantages. Various synthesis pathways for NMs, including traditional synthesis (chemical and physical) and biological synthesis pathways, mechanisms of reaction for pollutants removal using NMs, such as adsorption, filtration, disinfection, photocatalysis, and oxidation, also are evaluated. Additionally, this review presents suggestions for future investigation strategies to improve the efficacy of NMs in environmental remediation. The research so far provides strong evidence that NMs could effectively remove contaminants and may be valuable assets for various industrial purposes. However, further research and development are necessary to fully realize this potential, such as exploring new synthesis pathways and improving the dispersion and retention of NMs in the environment. Furthermore, there is a need to compare the efficacy of different types of NMs for remediating specific pollutants. Overall, this review highlights the immense potential of NMs for mitigating environmental pollutants and calls for more research in this direction.

From nature to nanotechnology: The interplay of traditional medicine, green chemistry, and biogenic metallic phytonanoparticles in modern healthcare innovation and sustainability

As we navigate the modern era, the intersection of time-honoured natural remedies and contemporary scientific approaches forms a burgeoning frontier in global healthcare. For generations, natural products have been foundational to health solutions, serving as the primary healthcare choice for 80% to 85% of the world's population. These herbal-based, nature-derived substances, significant across diverse geographies, necessitate a renewed emphasis on enhancing their quality, efficacy, and safety. In the current century, the advent of biogenic phytonanoparticles has emerged as an innovative therapeutic conduit, perfectly aligning with principles of environmental safety and scientific ingenuity. Utilizing green chemistry techniques, a spectrum of metallic nanoparticles including elements such as copper, silver, iron, zinc, and titanium oxide can be produced with attributes of non-toxicity, sustainability, and economic efficiency. Sophisticated herb-mediated processes yield an array of plant-originated nanomaterials, each demonstrating unique physical, chemical, and biological characteristics. These attributes herald new therapeutic potentials, encompassing antioxidants, anti-aging applications, and more. Modern technology further accelerates the synthesis of natural products within laboratory settings, providing an efficient alternative to conventional isolation methods. The collaboration between traditional wisdom and advanced methodologies now signals a new epoch in healthcare. Here, the augmentation of traditional medicine is realized through rigorous scientific examination. By intertwining ethical considerations, cutting-edge technology, and natural philosophy, the realms of biogenic phytonanoparticles and traditional medicine forge promising pathways for research, development, and healing. The narrative of this seamless integration marks an exciting evolution in healthcare, where the fusion of sustainability and innovation crafts a future filled with endless possibilities for human well-being. The research in the development of metallic nanoparticles is crucial for unlocking their potential in revolutionizing fields such as medicine, catalysis, and electronics, promising groundbreaking applications with enhanced efficiency and tailored functionalities in future technologies. This exploration is essential for harnessing the unique properties of metallic nanoparticles to address pressing challenges and advance innovations across diverse scientific and industrial domains.

The role of nanoparticles and nanomaterials in cancer diagnosis and treatment: a comprehensive review

Cancer's pathological processes are complex and present several challenges for current chemotherapy methods. These challenges include cytotoxicity, multidrug resistance, the proliferation of cancer stem cells, and a lack of specificity. To address these issues, researchers have turned to nanomaterials, which possess distinct optical, magnetic, and electrical properties due to their size range of 1-100 nm. Nanomaterials have been engineered to improve cancer treatment by mitigating cytotoxicity, enhancing specificity, increasing drug payload capacity, and improving drug bioavailability. Despite a growing corpus of research on this subject, there has been limited progress in permitting nanodrugs for medical use. The advent of nanotechnology, particularly advances in intelligent nanomaterials, has transformed the field of cancer diagnosis and therapy. Nanoparticles' large surface area allows them to successfully encapsulate a large number of molecules. Nanoparticles can be functionalized with various bio-based substrates like RNA, DNA, aptamers, and antibodies, enhancing their theranostic capabilities. Biologically derived nanomaterials offer economical, easily producible, and less toxic alternatives to conventionally manufactured ones. This review offers a comprehensive overview of cancer theranostics methodologies, focusing on intelligent nanomaterials such as metal, polymeric, and carbon-based nanoparticles. I have also critically discussed their benefits and challenges in cancer therapy and diagnostics. Utilizing intelligent nanomaterials holds promise for advancing cancer theranostics, and improving tumor detection and treatment. Further research should optimize nanocarriers for targeted drug delivery and explore enhanced permeability, cytotoxicity, and retention effects.

Critical evaluation of key parameters in single particle ICP-MS data processing for the correct determination of platinum nanoparticles in complex environmental and biological matrices

There is an urgent need for the harmonization of critical parameters in single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) and they have been deeply studied and optimized in the present work using platinum nanoparticles (PtNPs) as a representative case of study. Special attention has been paid to data processing in order to achieve an adequate discrimination between signals. Thus, a comparison between four different algorithms has been performed and the method for transport efficiency calculation has also been thorougly evaluated (finding the use of a well-characterized solution of the same targeted analyte (30 nm PtNPs) as adequate). The best results have been obtained after the application of a deconvolution approach for the data processing and using 5 ms as dwell time and 40,000 data points for data acquisition. Under the optimized conditions, a correct discrimination between NP events and background signal up to 100 or 750 ng L-1 of added ionic Pt was reached for 30 and 50 nm PtNPs, respectively. The suitability of the developed method for the characterization of PtNPs in relevant environmental (water samples) and biological (cell culture media) matrices has also been demonstrated.

Green Synthesis of Metal and Metal Oxide Nanoparticles: A Review of the Principles and Biomedical Applications

In recent years, interest in nanotechnology has increased exponentially due to enhanced progress and technological innovation. In tissue engineering, the development of metallic nanoparticles has been amplified, especially due to their antibacterial properties. Another important characteristic of metal NPs is that they enable high control over the features of the developed scaffolds (optimizing their mechanical strength and offering the controlled release of bioactive agents). Currently, the main concern related to the method of synthesis of metal oxide NPs is the environmental impact. The physical and chemical synthesis uses toxic agents that could generate hazards or exert carcinogenicity/environmental toxicity. Therefore, a greener, cleaner, and more reliable approach is needed. Green synthetic has come as a solution to counter the aforementioned limitations. Nowadays, green synthesis is preferred because it leads to the prevention/minimization of waste, the reduction of derivatives/pollution, and the use of non-toxic (safer) solvents. This method not only uses biomass sources as reducing agents for metal salts. The biomolecules also cover the synthesized NPs or act as in situ capping and reducing agents. Further, their involvement in the formation process reduces toxicity, prevents nanoparticle agglomeration, and improves the antimicrobial activity of the nanomaterial, leading to a possible synergistic effect. This study aims to provide a comprehensive review of the green synthesis of metal and metal oxide nanoparticles, from the synthesis routes, selected solvents, and parameters to their latest application in the biomedical field.

Advancements in Nanoparticle Deposition Techniques for Diverse Substrates: A Review

Nanoparticle deposition on various substrates has gained significant attention due to the potential applications of nanoparticles in various fields. This review paper comprehensively analyzes different nanoparticle deposition techniques on ceramic, polymeric, and metallic substrates. The deposition techniques covered include electron gun evaporation, physical vapor deposition, plasma enriched chemical vapor deposition (PECVD), electrochemical deposition, chemical vapor deposition, electrophoretic deposition, laser metal deposition, and atomic layer deposition (ALD), thermophoretic deposition, supercritical deposition, spin coating, and dip coating. Additionally, the sustainability aspects of these deposition techniques are discussed, along with their potential applications in anti-icing, antibacterial power, and filtration systems. Finally, the review explores the importance of deposition purities in achieving optimal nanomaterial performance. This comprehensive review aims to provide valuable insights into state-of-the-art techniques and applications in the field of nanomaterial deposition.

Anti-inflammatory potential of platinum nanozymes: mechanisms and perspectives

Inflammation is a complex process of the body in response to pathogen infections or dysregulated metabolism, involving the recruitment and activation of immune system components. Repeated dangerous stimuli or uncontrolled immune effector mechanisms can result in tissue injury. Reactive Oxygen Species (ROS) play key roles in physiological cell signaling as well as in the destruction of internalized pathogens. However, aberrant ROS production and release have deleterious effects on the surrounding environment, making ROS regulation a priority to reduce inflammation. Most of the current anti-inflammatory therapies rely on drugs that impair the release of pro-inflammatory mediators. Nevertheless, increasing the enzymatic activity to reduce ROS levels could be an alternative or complementary therapeutic approach to decrease inflammation. Nanozymes are nanomaterials with high catalytic activity that mimic natural enzymes, allowing biochemical reactions to take place. Such functional particles typically show different and regenerable oxidation states or catalytically reactive surfaces offering long-term activity and stability. In this scenario, platinum-based nanozymes (PtNZs) exhibit broad and efficient catalytic functionalities and can reduce inflammation mainly through ROS scavenging, e.g. by catalase and superoxide dismutase reactions. Dose-dependent biocompatibility and immune compatibility of PtNZs have been shown in different cells and tissues, both in vitro and in vivo. Size/shape/surface engineering of the nanozymes could also potentiate their efficacy to act at different sites and/or steps of the inflammation process, such as cytokine removal or specific targeting of activated leukocytes. In the present review, we analyze key inflammation triggering processes and the effects of platinum nanozymes under exemplificative inflammatory conditions. We further discuss potential platinum nanozyme design and improvements to modulate and expand their anti-inflammatory action.

Microwave-Assisted Synthesis of Pt/SnO2 for the Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol

In this study, we present a new approach for the synthesis of Pt/SnO2 catalysts using microwave radiation. Pt(IV) and Sn(IV) inorganic precursors (H2PtCl6 and SnCl4) and ammonia were used, which allowed the controlled formation of platinum particles on the anisotropic SnO2 support. The synthesized Pt/SnO2 samples are mesoporous and exhibit a reversible physisorption isotherm of type IV. The XRD patterns confirmed the presence of platinum maxima in all Pt/SnO2 samples. The Williamson-Hall diagram showed SnO2 anisotropy with crystallite sizes of ~10 nm along the c-axis (< 00l >) and ~5 nm along the a-axis (< h00 >). SEM analysis revealed anisotropic, urchin-like SnO2 particles. XPS results indicated relatively low average oxidation states of platinum, close to Pt metal. 119Sn Mössbauer spectroscopy indicated electronic interactions between Pt and SnO2 particles. The synthesized samples were used for the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of excess NaBH4. The catalytic activity of the Pt/SnO2 samples for the reduction of 4-NP to 4-AP was optimized by varying the synthesis parameters and Pt loading. The optimal platinum loading for the reduction of 4-NP to 4-AP on the anisotropic SnO2 support is 5 mol% with an apparent rate constant k = 0.59 × 10-2 s-1. The Pt/SnO2 sample showed exceptional reusability and retained an efficiency of 81.4% after ten cycles.

Nanotechnology enabled radioprotectants to reduce space radiation-induced reactive oxidative species

Interest in space exploration has seen substantial growth following recent launch and operation of modern space technologies. In particular, the possibility of travel beyond low earth orbit is seeing sustained support. However, future deep space travel requires addressing health concerns for crews under continuous, longer-term exposure to adverse environmental conditions. Among these challenges, radiation-induced health issues are a major concern. Their potential to induce chronic illness is further potentiated by the microgravity environment. While investigations into the physiological effects of space radiation are still under investigation, studies on model ionizing radiation conditions, in earth and micro-gravity conditions, can provide needed insight into relevant processes. Substantial formation of high, sustained reactive oxygen species (ROS) evolution during radiation exposure is a clear threat to physiological health of space travelers, producing indirect damage to various cell structures and requiring therapeutic address. Radioprotection toward the skeletal system components is essential to astronaut health, due to the high radio-absorption cross-section of bone mineral and local hematopoiesis. Nanotechnology can potentially function as radioprotectant and radiomitigating agents toward ROS and direct radiation damage. Nanoparticle compositions such as gold, silver, platinum, carbon-based materials, silica, transition metal dichalcogenides, and ceria have all shown potential as viable radioprotectants to mitigate space radiation effects with nanoceria further showing the ability to protect genetic material from oxidative damage in several studies. As research into space radiation-induced health problems develops, this review intends to provide insights into the nanomaterial design to ameliorate pathological effects from ionizing radiation exposure. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Nanotechnology Approaches to Biology > Cells at the Nanoscale Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Facile construction of drugs loaded lipid-coated calcium carbonate as a promising pH-Dependent drug delivery system for thyroid cancer treatment

To develop innovative drug delivery carriers for controllable release and cancer-targeted delivery of therapeutic agents to accomplish efficient cancer chemotherapy. Herein we effectively fabricated CaCO3 primarily loaded biotin (BT) and directly the self-assembly of oxaliplatin (Pt (IV)) prodrugs form in liposomes. The acquired BT-Pt (IV)@PEG/CaCO3 with outstanding biological stability displays rapid pH-mediated degradations, thus allowing the effective pH-responsive delivery of BT. In vitro, anticancer assays proved that BT-Pt (IV)@PEG/CaCO3 effectively kills the thyroid cancer cells (B-CPAP and FTC-133). The biochemical staining assays investigated the morphological changes of thyroid cancer after treatment with nanoparticles. The DNA fragmentation of the cells was assessed by utilizing the comet assay. BT-Pt (IV)@PEG/CaCO3 increased ROS levels and caused mitochondrial membrane potential and DNA damage, which resulted in apoptosis. Due to its versatile drug-loading capability, this research demonstrates that CaCO3 liposomal formulation is a biocompatible and reliable substrate for establishing pH-mediated drug delivery methods and promising for possible therapeutic application.

Biomedical,clinical and environmental applications of platinum-based nanohybrids: An updated review

Platinum nanoparticles (Pt NPs) have numerous applications in various sectors, including pharmacology, nanomedicine, cancer therapy, radiotherapy, biotechnology and environment mitigation like removal of toxic metals from wastewater, photocatalytic degradation of toxic compounds, adsorption, and water splitting. The multifaceted applications of Pt NPs because of their ultra-fine structures, large surface area, tuned porosity, coordination-binding, and excellent physiochemical properties. The various types of nanohybrids (NHs) of Pt NPs can be fabricated by doping with different metal/metal oxide/polymer-based materials. There are several methods to synthesize platinum-based NHs, but biological processes are admirable because of green, economical, sustainable, and non-toxic. Due to the robust physicochemical and biological characteristics of platinum NPs, they are widely employed as nanocatalyst, antioxidant, antipathogenic, and anticancer agents. Indeed, Pt-based NHs are the subject of keen interest and substantial research area for biomedical and clinical applications. Hence, this review systematically studies antimicrobial, biological, and environmental applications of platinum and platinum-based NHs, predominantly for treating cancer and photo-thermal therapy. Applications of Pt NPs in nanomedicine and nano-diagnosis are also highlighted. Pt NPs-related nanotoxicity and the potential and opportunity for future nano-therapeutics based on Pt NPs are also discussed.

Antibacterial Activity of PVA Hydrogels Embedding Oxide Nanostructures Sensitized by Noble Metals and Ruthenium Dye

Nanostructured oxides (SiO2, TiO2) were synthesized using the sol-gel method and modified with noble metal nanoparticles (Pt, Au) and ruthenium dye to enhance light harvesting and promote the photogeneration of reactive oxygen species, namely singlet oxygen (1O2) and hydroxyl radical (•OH). The resulting nanostructures were embedded in a transparent polyvinyl alcohol (PVA) hydrogel. Morphological and structural characterization of the bare and modified oxides was performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), UV-Vis spectroscopy, and X-ray photoelectron spectroscopy (XPS). Additionally, electrokinetic potential measurements were conducted. Crystallinity data and elemental analysis of the investigated systems were obtained through X-ray diffraction and X-ray fluorescence analyses, while the chemical state of the elements was determined using XPS. The engineered materials, both as simple powders and embedded in the hydrogel, were evaluated for their ability to generate reactive oxygen species (ROS) under visible and simulated solar light irradiation to establish a correlation with their antibacterial activity against Staphylococcus aureus. The generation of singlet oxygen (1O2) by the samples under visible light exposure can be of significant importance for their potential use in biomedical applications.

Antioxidant potential of nanomaterials

Background/aim

The novel field of nanomaterials allows infinite possibilities in order to create antioxidant therapies. The present review is aimed to describe the state of art concerning on nanomaterials and their effects on reactive oxygen species (ROS) production. A wide range of nanoparticles has been designed for this purpose, and each one possesses some particular characteristics which allow these significant antioxidant results. Several in vivo and in vitro works state the ability of these nanoparticles to mimic the redox systems of the cells, and thus, the potential role of nanoparticles as antioxidant treatment for several diseases.

Materials and methods

This paper was written after a review of the articles published on the field, using the "PubMed" and "Research Gate" databases.

Results

The main types of nanoparticles are listed and explained below, offering a global vision of the field with great interest for research. Antitumor chemo- and radiotherapies have been found to improve efficacy by enhancing the selectivity of cytocidal effects and minimizing systemic adverse effects when such materials are used. Furthermore, catalytic nanomaterials can execute energy-free antioxidant cycles that scavenge the most harmful reactive oxygen species via SOD- and catalase-like activities.

Conclusion

This unique method is projected to result in significant gains in the long run. However, due to a lack of understanding of potential adverse body reactions to these novel strategies, caution must be exercised. Analyzing the biocompatibility of these nanomaterials carefully, particularly in terms of biokinetics and the problems that could arise from long-term retention of nonbiodegradable inorganic nanomaterials, is required.

Recovery of platinum group metals from spent automotive converters and their conversion into efficient recyclable nanocatalysts

The study reported in this article has shown for the first time that strongly acidic solutions (pH < 0.5) obtained after hydrometallurgical treatment of spent automotive converters (SAC) may be valuable secondary sources of platinum group metal (PGM) nanoparticles (NPs). The PGM precipitation strongly depended on the solution pH; the yield of the precipitated PGM NPs increased considerably from 40% to almost 100% when the pH was adjusted to 7-8. To improve the NPs stability, commercial TiO2 was used as support to obtain efficient recyclable PGM@TiO2 catalysts. The size of the PGM NPs was smaller than 5 nm, while the diameter of the supported particles varied from 10 to 50 nm. The size and dispersion of PGM NPs on the support strongly depended on the pH of the medium: at pH < 0.5, the Pt and Pd NPs were significantly smaller than the NPs obtained at pH 7-8. Also, in the case of Pt@TiO2 and Rh@TiO2, the NPs were well dispersed on the support in contrast to the large agglomerates of Pd@TiO2. The PGM@TiO2 showed catalytic properties in the reduction of 4-nitrophenol to 4-aminophenol, particularly, at pH above 11. The highest conversion of 98% was obtained with 1% Pd@TiO2 at pH 14 after only 15 min. The catalyst was easily separated from the reaction mixture and reused in 7 consecutive cycles without significant loss of activity. The PGM@TiO2 synthesized from the real solution showed a similar catalytic activity (70% conversion at pH 14) as that obtained from model solution.

Production of Ceramics/Metal Oxide Nanofibers via Electrospinning: New Insights into the Photocatalytic and Bactericidal Mechanisms

Environmental pollution is steadily rising and is having a negative influence on all living things, especially human beings. The advancement of nanoscience in recent decades has provided potential to address this issue. Functional metal oxide nanoparticles/nanofibers have been having a pull-on effect in the biological and environmental domains of nanobiotechnology. Current work, for the first time, is focusing on the electrospinning production of Zr_0.5Sn_0.5TiO₃/SnO₂ ceramic nanofibers that may be utilized to battle lethal infections swiftly and inexpensively. By using characterizations like XRD, FT-IR, FESEM, TEM, PL, and UV-Vis-DRS, the composition, structure, morphology, and optical absorption of samples were determined. The minimum inhibitory concentration (MIC) approach was used to investigate the antibacterial activity. Notably, this research indicated that nanofibers exert antibacterial action against both Gram-positive and Gram-negative bacteria with a MIC of 25 µg/mL. Furthermore, negatively charged E. coli was drawn to positively charged metal ions of Zr_0.5Sn_0.5TiO₃/SnO₂, which showed a robust inhibitory effect against E. coli. It was interesting to discover that, compared to pure TiO₂, Zr_0.5Sn_0.5TiO₃/SnO₂ nanofibers revealed increased photocatalytic activity and exceptional cyclability to the photodegradation of Rhodamine B. The composite completely degrades dye in 30 min with 100% efficacy and excellent (97%) reusability. The synergetic effects of Zr_0.5Sn_0.5TiO₃ and SnO₂ may be responsible for increased photocatalytic and bactericidal activity.

Biosynthesis of Quantum Dots and Their Therapeutic Applications in the Diagnosis and Treatment of Cancer and SARS-CoV-2

Quantum dots (QDs) are semiconductor materials that range from 2 nm to 10 nm. These nanomaterials (NMs) are smaller and have more unique properties compared to conventional nanoparticles (NPs). One of the unique properties of QDs is their special optoelectronic properties, making it possible to apply these NMs in bioimaging. Different size and shape QDs, which are used in various fields such as bioimaging, biosensing, cancer therapy, and drug delivery, have so far been produced by chemical methods. However, chemical synthesis provides expensive routes and causes serious environmental and health issues. Therefore, various biological systems such as bacteria, fungi, yeasts, algae, and plants are considered as potent eco-friendly green nanofactories for the biosynthesis of QDs, which are both economic and environmentally safe. The review aims to provide a descriptive overview of the various microbial agents for the synthesis of QDs and their biomedical applications for the diagnosis and treatment of cancer and SARS-CoV-2.

Hyaluronic Acid Modified Metal Nanoparticles and Their Derived Substituents for Cancer Therapy: A Review

The use of metal nanoparticles (M-NPs) in cancer therapy has gained significant consideration owing to their exceptional physical and chemical features. However, due to the limitations, such as specificity and toxicity towards healthy cells, their application in clinical translations has been restricted. Hyaluronic acid (HA), a biocompatible and biodegradable polysaccharide, has been extensively used as a targeting moiety, due to its ability to selectively bind to the CD44 receptors overexpressed on cancer cells. The HA-modified M-NPs have demonstrated promising results in improving specificity and efficacy in cancer therapy. This review discusses the significance of nanotechnology, the state of cancers, and the functions of HA-modified M-NPs, and other substituents in cancer therapy applications. Additionally, the role of various types of selected noble and non-noble M-NPs used in cancer therapy are described, along with the mechanisms involved in cancer targeting. Additionally, the purpose of HA, its sources and production processes, as well as its chemical and biological properties are described. In-depth explanations are provided about the contemporary applications of HA-modified noble and non-noble M-NPs and other substituents in cancer therapy. Furthermore, potential obstacles in optimizing HA-modified M-NPs, in terms of clinical translations, are discussed, followed by a conclusion and future prospects.

Bio-inspired nanoparticles mediated from plant extract biomolecules and their therapeutic application in cardiovascular diseases: A review

Nanoparticles (NPs) have gained recognition for diagnosis, drug delivery, and therapy in fatal diseases. This review focuses on the benefits of green synthesis of bioinspired NPs using various plant extract (containing various biomolecules such as sugars, proteins, and other phytochemical compounds) and their therapeutic application in cardiovascular diseases (CVDs). Multiple factors including inflammation, mitochondrial and cardiomyocyte mutations, endothelial cell apoptosis, and administration of non-cardiac drugs, can trigger the cause of cardiac disorders. Furthermore, the interruption of reactive oxygen species (ROS) synchronization from mitochondria causes oxidative stress in the cardiac system, leading to chronic diseases such as atherosclerosis and myocardial infarction. NPs can decrease the interaction with biomolecules and prevent the incitement of ROS. Understanding this mechanism can pave the way for using green synthesized elemental NPs to reduce the risk of CVD. This review delivers information on the different methods, classifications, mechanisms and benefits of using NPs, as well as the formation and progression of CVDs and their effects on the body.

Intermediates during the Nucleation of Platinum Nanoparticles by a Reaction with Ethylene Glycol: Operando X-ray Absorption Spectroscopy Studies with a Microfluidic Cell

Using operando X-ray absorption spectroscopy in a continuous-flow microfluidic cell, we have investigated the nucleation of platinum nanoparticles from aqueous hexachloroplatinate solution in the presence of the reducing agent ethylene glycol. By adjusting flow rates in the microfluidic channel, we resolved the temporal evolution of the reaction system in the first few seconds, generating the time profiles for speciation, ligand exchange, and reduction of Pt. Detailed analysis of the X-ray absorption near-edge structure and extended X-ray absorption fine structure spectra with multivariate data analysis shows that at least two reaction intermediates are involved in the transformation of the precursor H₂PtCl₆ to metallic platinum nanoparticles, including the formation of clusters with Pt-Pt bonding before complete reduction to Pt nanoparticles.

Current Progress in Conductive Hydrogels and Their Applications in Wearable Bioelectronics and Therapeutics

Wearable bioelectronics and therapeutics are a rapidly evolving area of research, with researchers exploring new materials that offer greater flexibility and sophistication. Conductive hydrogels have emerged as a promising material due to their tunable electrical properties, flexible mechanical properties, high elasticity, stretchability, excellent biocompatibility, and responsiveness to stimuli. This review presents an overview of recent breakthroughs in conductive hydrogels, including their materials, classification, and applications. By providing a comprehensive review of current research, this paper aims to equip researchers with a deeper understanding of conductive hydrogels and inspire new design approaches for various healthcare applications.

Synthesis Methods and Optical Sensing Applications of Plasmonic Metal Nanoparticles Made from Rhodium, Platinum, Gold, or Silver

The purpose of this paper is to provide an in-depth review of plasmonic metal nanoparticles made from rhodium, platinum, gold, or silver. We describe fundamental concepts, synthesis methods, and optical sensing applications of these nanoparticles. Plasmonic metal nanoparticles have received a lot of interest due to various applications, such as optical sensors, single-molecule detection, single-cell detection, pathogen detection, environmental contaminant monitoring, cancer diagnostics, biomedicine, and food and health safety monitoring. They provide a promising platform for highly sensitive detection of various analytes. Due to strongly localized optical fields in the hot-spot region near metal nanoparticles, they have the potential for plasmon-enhanced optical sensing applications, including metal-enhanced fluorescence (MEF), surface-enhanced Raman scattering (SERS), and biomedical imaging. We explain the plasmonic enhancement through electromagnetic theory and confirm it with finite-difference time-domain numerical simulations. Moreover, we examine how the localized surface plasmon resonance effects of gold and silver nanoparticles have been utilized for the detection and biosensing of various analytes. Specifically, we discuss the syntheses and applications of rhodium and platinum nanoparticles for the UV plasmonics such as UV-MEF and UV-SERS. Finally, we provide an overview of chemical, physical, and green methods for synthesizing these nanoparticles. We hope that this paper will promote further interest in the optical sensing applications of plasmonic metal nanoparticles in the UV and visible ranges.

Bio-Fabrication of Silver Nanoparticles Using Citrus aurantifolia Fruit Peel Extract (CAFPE) and the Role of Plant Extract in the Synthesis

The green synthesis of silver nanoparticles has been proposed as an eco-friendly and cost-effective substitute for chemical and physical methods. The aim of this study was to synthesize and characterize silver nanoparticles using the peel extract of Citrus aurantifolia fruit, and to determine the possible phytochemical constituents' presence in the plant extracts that might be responsible for the synthesis. Citrus aurantifolia fruit peel extraction was followed by phytochemical studies of secondary metabolites, FTIR analysis confirmation of functional groups, and GC-MS analysis. Silver nanoparticles were synthesized through bio-reduction of silver ions (Ag⁺) to silver nanoparticles using CAFPE and characterized using UV-Vis spectroscopy, HR-TEM, FESEM, EDX, XRD, DLS, and FTIR. The presence of plant secondary metabolites such as alkaloids, flavonoids, tannins, saponins, phenols, terpenoids, and steroids was detected. The FTIR analysis of the extract revealed the presence of functional groups like hydroxyl, carboxyl, carbonyl, amine, and phenyl, whereas the GC-MS analysis indicated presence of chemical compounds such as 1,2,4-Benzenetricarboxylic acid, Fumaric acid, nonyl pentadecyl, and 4-Methyl-2-trimethylsilyloxy-acetophenone, etc., with similar functional groups. The synthesized silver nanoparticle (AgNP) has displayed the characteristics of a surface plasmon resonance (SPR) band peak from 360-405 nm. High resolution transmission electron microscope (HR-TEM) and field emission scan electron microscope (FESEM) confirm polydisperse, spherical shaped, and smooth surface nanoparticles with an average size of 24.023 nm. Energy dispersive X-ray (EDX) analysis further revealed that silver is the most abundant element found in the micrograph of the nanoparticles, and FTIR analysis further confirmed the presence of different functional groups in the surface of the nanoparticle. The XRD analysis also confirmed that the nanoparticles synthesized are crystalline in nature. Based on the findings of this study, it is understood that the variety of natural compounds that are present in plant extracts of Citrus aurantifolia fruit peel can act as both reducing and stabilizing agents for the synthesis of silver nanoparticles. It is, therefore, concluded that Citrus aurantifolia peel extract can be potentially used for the large production of silver nanoparticles for several applications.

Review on Carbon Dot-Based Fluorescent Detection of Biothiols

Biothiols, such as cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), play a vital role in gene expression, maintaining redox homeostasis, reducing damages caused by free radicals/toxins, etc. Likewise, abnormal levels of biothiols can lead to severe diseases, such as Alzheimer's disease (AD), neurotoxicity, hair depigmentation, liver/skin damage, etc. To quantify the biothiols in a biological system, numerous low-toxic probes, such as fluorescent quantum dots, emissive organic probes, composited nanomaterials, etc., have been reported with real-time applications. Among these fluorescent probes, carbon-dots (CDs) have become attractive for biothiols quantification because of advantages of easy synthesis, nano-size, crystalline properties, low-toxicity, and real-time applicability. A CDs-based biothiols assay can be achieved by fluorescent "Turn-On" and "Turn-Off" responses via direct binding, metal complex-mediated detection, composite enhanced interaction, reaction-based reports, and so forth. To date, the availability of a review focused on fluorescent CDs-based biothiols detection with information on recent trends, mechanistic aspects, linear ranges, LODs, and real applications is lacking, which allows us to deliver this comprehensive review. This review delivers valuable information on reported carbon-dots-based biothiols assays, the underlying mechanism, their applications, probe/CDs selection, sensory requirement, merits, limitations, and future scopes.

Progress in the preparation of Prussian blue-based nanomaterials for biomedical applications

Prussian blue (PB) is composed of the coordination network of Fe²⁺-CN-Fe³⁺ mixed valence state as a classic metal complex, which includes a C atom and Fe²⁺ (low spin), N atom and Fe³⁺ (high spin). PB and its analogues (PBA) have excellent biosafety, good magnetic properties, outstanding photothermal properties and the ability to mimic enzymatic behaviors due to their stable structure, tunable size, controllable morphology, abundant modification methods and excellent physicochemical properties. They have received increasing research interest and have shown promising applications in the biomedical field. Here, progress in the preparation of PB-based nanomaterials for biomedical applications is summarized and discussed. The preparation strategies, traditional synthesis and emerging preparation methods of PB are summarized systematically in this review. The design and preparation of PBA, PB(PBA)-based hollow structures and PB(PBA)-based composites are also included. While introducing the preparation status, some PB-based nanomaterials that have performed well in specific biomedical fields are emphasized. More importantly, the key factors and future development of PB for the clinical translation as multifunctional nanomaterials are also discussed. This review provides a reference for the design and biomedical application of PB-based nanomaterials.

Inter-Organelle Contact Sites Mediate the Intracellular Antioxidant Activity of Platinum Nanozymes: A New Perspective on Cell-Nanoparticle Interaction and Signaling

The catalytic and antioxidant properties of platinum nanoparticles (PtNPs) make them promising candidates for several applications in nanomedicine. However, an open issue, still shared among most nanomaterials, is the understanding on how internalized PtNPs, which are confined within endo-lysosomal compartments, can exert their activities. To address this problem, here we study the protective effect of 5 nm PtNPs on a human hepatic (HepG2) cell line exposed to dichlorodiphenylethylene (DDE) as a model of oxidative stress. Our results indicate that PtNPs are very efficient to reduce DDE-induced damage in HepG2 cells, in an extent that depends on DDE dose. PtNPs can contrast the unbalance of mitochondrial dynamics induced by DDE and increase the expression of the SOD2 mitochondrial enzyme that recovers cells from oxidative stress. Interestingly, in cells treated with PtNPs─alone or in combination with DDE─mitochondria form contact sites with a rough endoplasmic reticulum and endo-lysosomes containing nanoparticles. These findings indicate that the protective capability of PtNPs, through their intrinsic antioxidant properties and modulating mitochondrial functionality, is mediated by an inter-organelle crosstalk. This study sheds new light about the protective action mechanisms of PtNPs and discloses a novel nano-biointeraction mechanism at the intracellular level, modulated by inter-organelle communication and signaling.

Biological Use of Nanostructured Silica-Based Materials Functionalized with Metallodrugs: The Spanish Perspective

Since the pioneering work of Vallet-Regí's group on the design and synthesis of mesoporous silica-based materials with therapeutic applications, during the last 15 years, the potential use of mesoporous silica nanostructured materials as drug delivery vehicles has been extensively explored. The versatility of these materials allows the design of a wide variety of platforms that can incorporate numerous agents of interest (fluorophores, proteins, drugs, etc.) in a single scaffold. However, the use of these systems loaded with metallodrugs as cytotoxic agents against different diseases and with distinct therapeutic targets has been studied to a much lesser extent. This review will focus on the work carried out in this field, highlighting both the pioneering and recent contributions of Spanish groups that have synthesized a wide variety of systems based on titanium, tin, ruthenium, copper and silver complexes supported onto nanostructured silica. In addition, this article will also discuss the importance of the structural features of the systems for evaluating and modulating their therapeutic properties. Finally, the most interesting results obtained in the study of the potential therapeutic application of these metallodrug-functionalized silica-based materials against cancer and bacteria will be described, paying special attention to preclinical trials in vivo.

An Insight into Current Treatment Strategies, Their Limitations, and Ongoing Developments in Vaccine Technologies against Herpes Simplex Infections

Herpes simplex virus (HSV) infection, the most prevalent viral infection that typically lasts for a lifetime, is associated with frequent outbreaks of oral and genital lesions. Oral herpes infection is mainly associated with HSV-1 through oral contact, while genital herpes originates due to HSV-2 and is categorized under sexually transmitted diseases. Immunocompromised patients and children are more prone to HSV infection. Over the years, various attempts have been made to find potential targets for the prevention of HSV infection. Despite the global distress caused by HSV infections, there are no licensed prophylactic and therapeutic vaccines available on the market against HSV. Nevertheless, there are numerous promising candidates in the pre-clinical and clinical stages of study. The present review gives an overview of two herpes viruses, their history, and life cycle, and different treatments adopted presently against HSV infections and their associated limitations. Majorly, the review covers the recent investigations being carried out globally regarding various vaccine strategies against oral and genital herpes virus infections, together with the recent and advanced nanotechnological approaches for vaccine development. Consequently, it gives an insight to researchers as well as people from the health sector about the challenges and upcoming solutions associated with treatment and vaccine development against HSV infections.

Plant and Microbial Approaches as Green Methods for the Synthesis of Nanomaterials: Synthesis, Applications, and Future Perspectives

The unique biological and physicochemical characteristics of biogenic (green-synthesized) nanomaterials (NMs) have attracted significant interest in different fields, with applications in the agrochemical, food, medication delivery, cosmetics, cellular imaging, and biomedical industries. To synthesize biogenic nanomaterials, green synthesis techniques use microorganisms, plant extracts, or proteins as bio-capping and bio-reducing agents and their role as bio-nanofactories for material synthesis at the nanoscale size. Green chemistry is environmentally benign, biocompatible, nontoxic, and economically effective. By taking into account the findings from recent investigations, we shed light on the most recent developments in the green synthesis of nanomaterials using different types of microbes and plants. Additionally, we cover different applications of green-synthesized nanomaterials in the food and textile industries, water treatment, and biomedical applications. Furthermore, we discuss the future perspectives of the green synthesis of nanomaterials to advance their production and applications.

Self-Therapeutic Nanomaterials: Applications in Biology and Medicine

Over past decades, nanotechnology has contributed to the biomedical field in areas including detection, diagnosis, and drug delivery via opto-electronic properties or enhancement of biological effects. Though generally considered inert delivery vehicles, a plethora of past and present evidence demonstrates that nanomaterials also exude unique intrinsic biological activity based on composition, shape, and surface functionalization. These intrinsic biological activities, termed self-therapeutic properties, take several forms, including mediation of cell-cell interactions, modulation of interactions between biomolecules, catalytic amplification of biochemical reactions, and alteration of biological signal transduction events. Moreover, study of biomolecule-nanomaterial interactions offers a promising avenue for uncovering the molecular mechanisms of biology and the evolution of disease. In this review, we observe the historical development, synthesis, and characterization of self-therapeutic nanomaterials. Next, we discuss nanomaterial interactions with biological systems, starting with administration and concluding with elimination. Finally, we apply this materials perspective to advances in intrinsic nanotherapies across the biomedical field, from cancer therapy to treatment of microbial infections and tissue regeneration. We conclude with a description of self-therapeutic nanomaterials in clinical trials and share our perspective on the direction of the field in upcoming years.

Diversity of Biogenic Nanoparticles Obtained by the Fungi-Mediated Synthesis: A Review

Fungi are very promising biological objects for the green synthesis of nanoparticles. Biogenic synthesis of nanoparticles using different mycological cultures and substances obtained from them is a promising, easy and environmentally friendly method. By varying the synthesis conditions, the same culture can be used to produce nanoparticles with different sizes, shapes, stability in colloids and, therefore, different biological activity. Fungi are capable of producing a wide range of biologically active compounds and have a powerful enzymatic system that allows them to form nanoparticles of various chemical elements. This review attempts to summarize and provide a comparative analysis of the currently accumulated data, including, among others, our research group's works, on the variety of the characteristics of the nanoparticles produced by various fungal species, their mycelium, fruiting bodies, extracts and purified fungal metabolites.

Milk-Derived Carbon Quantum Dots: Study of Biological and Chemical Properties Provides Evidence of Toxicity

Carbon dots (CDs) are carbon-based zero-dimensional nanomaterials that can be prepared from a number of organic precursors. In this research, they are prepared using fat-free UHT cow milk through the hydrothermal method. FTIR analysis shows C=O and C-H bond presence, as well as nitrogen-based bond like C-N, C=N and -NH₂ presence in CDs, while the absorption spectra show the absorption band at 280 ± 3 nm. Next, the Biuret test was performed, with the results showing no presence of unreacted proteins in CDs. It can be said that all proteins are converted in CDs. Photo luminance spectra shows the emission of CDs is 420 nm and a toxicity study of CDs was performed. The Presto Blue method was used to test the toxicity of CDs for murine hippocampal cells. CDs at a concentration of 4 mg/mL were hazardous independent of synthesis time, while the toxicity was higher for lower synthesis times of 1 and 2 h. When the concentration is reduced in 1 and 2 h synthesized CDs, the cytotoxic effect also decreases significantly, ensuring a survival rate of 60-80%. However, when the synthesis time of CDs is increased, the cytotoxic effect decreases to a lesser extent. The CDs with the highest synthesis time of 8 h do not show a cytotoxic effect above 60%. The cytotoxicity study shows that CDs may have a concentration and time-dependent cytotoxic effect, reducing the number of viable cells by 40%.

The Therapeutic Potential of Algal Nanoparticles: A Brief Review

Recently, the green synthesis of metallic nanoparticles (NPs) has received tremendous attention as a simple approach. The green pathway of biogenic synthesis of metallic NPs through microbes may provide a sustainable and environmentally friendly protocol. Green technology is the most innovative technology for various biological activities and lacks toxic effects. Reports have shown the algae-mediated synthesis of metal NPs. Algae are widely used for biosynthesis as they grow fast; they produce biomass on average ten times that of plants and are easily utilized experimentally. In the future, the production of metal NPs by different microalgae and their biological activity can be explored in diverse areas such as catalysis, medical diagnosis, and anti-biofilm applications.

The Synthesis of Carbon Black-Loaded Pt Concave Nanocubes with High-Index Facets and Their Enhanced Electrocatalytic Properties toward Glucose Oxidation

Catalysts with high catalytic activity and good stability are desirable in the electrocatalytic oxidation of glucose. Herein, Pt concave nanocubes with high-index facets (HIFs) supported by carbon black (Pt CNC/CB) are prepared through a hydrothermal method. The experimental results demonstrate that the peak current densities in different potential regions on the Pt CNC/CB anode are 0.22, 0.20, and 0.60 mA cm^-2. The catalytic process of the glucose oxidation reaction is investigated in electrolytes with different pH values. Better stability is achieved by Pt CNC/CB than by Pt concave nanocubes (Pt CNCs). Abundant surface defects with low-coordinated atom numbers, such as steps, kinks, and edges, served as active sites in the electrocatalytic oxidation of glucose. With the addition of carbon black, the catalytic activity can be improved by facilitating the full exposure of the active surface defects on the HIFs of the Pt CNCs. Moreover, to address the aggregation of Pt CNCs, caused by the high surface energy of HIFs, the introduction of carbon material is an effective way to preserve the HIFs and thus enhance the stability of the catalyst. Hence, the prepared Pt CNC/CB electrocatalyst has great potential to be applied in the electrooxidation of glucose.

Retrospective analysis of the key molecules involved in the green synthesis of nanoparticles

Emerging nanotechnology leads to success in synthesizing and applying nanoparticles (NPs) using the green-chemistry approach. NPs synthesized using naturally derived materials are a potential alternative to chemical and physical methods because they are simple, cost-effective, eco-friendly, and lower the possibility of hazardous residues being released into the environment. Furthermore, NPs synthesized using the green synthesis approach are stable and biocompatible. However, because natural extracts contain a diverse spectrum of bioactive components, it is difficult to pinpoint the specific component involved in NP formation. Furthermore, the bioactive component contained in the extract changes based on a number of environmental factors; therefore, several studies began with the synthesis of NPs using a pure compound isolated from diverse natural sources. Hence, the present review paper makes an effort to retrospectively analyze the key compounds of the extracts which are responsible for the synthesis of the NPs. The analysis was carried out based on the physicochemical characteristics and biological activities of NPs synthesized from either the extract or the pure compounds. These pure-compound-based NPs were studied for their antimicrobial, antibiofilm, anti-inflammatory, anticancer, and antioxidant properties. In addition, the present review also describes progress in the study of pure compound-based numerous biological activities and the underlying mechanisms of action.

Medical and Dental Applications of Titania Nanoparticles: An Overview

Currently, titanium oxide (TiO₂) nanoparticles are successfully employed in human food, drugs, cosmetics, advanced medicine, and dentistry because of their non-cytotoxic, non-allergic, and bio-compatible nature when used in direct close contact with the human body. These NPs are the most versatile oxides as a result of their acceptable chemical stability, lower cost, strong oxidation properties, high refractive index, and enhanced aesthetics. These NPs are fabricated by conventional (physical and chemical) methods and the latest biological methods (biological, green, and biological derivatives), with their advantages and disadvantages in this epoch. The significance of TiO₂ NPs as a medical material includes drug delivery release, cancer therapy, orthopedic implants, biosensors, instruments, and devices, whereas their significance as a dental biomaterial involves dentifrices, oral antibacterial disinfectants, whitening agents, and adhesives. In addition, TiO₂ NPs play an important role in orthodontics (wires and brackets), endodontics (sealers and obturating materials), maxillofacial surgeries (implants and bone plates), prosthodontics (veneers, crowns, bridges, and acrylic resin dentures), and restorative dentistry (GIC and composites).