Platinum Nanoparticles: Green Synthesis and Biomedical Applications

Biotemplated Platinum Nanozymes: Synthesis, Catalytic Regulation and Biomedical Applications

Platinum (Pt) nanozymes with multiple intrinsic enzyme-mimicking activities have attracted extensive attention in biomedical fields due to their high catalytic activity, ease of modification, and convenient storage. However, the Pt nanozymes synthesized by the traditional method often suffer from uncontrollable morphology and poor stability under physicochemical conditions, resulting in unsatisfactory catalytic behavior in practical applications. To optimize the catalytic ability, biological templates have been introduced recently, which can guide the deposition of platinum ions on their surface to form specific morphologies and then stabilize the resulting Pt nanozymes. Given the promising potential of biotemplated Pt nanozymes in practical applications, it is essential to conduct a systematic and comprehensive review to summarize their recent research progress. In this review, we first categorize the biological templates and discuss the mechanisms as well as characteristics of each type of biotemplate in directing the growth of Pt nanozyme. Factors that impact the growth of biotemplated Pt nanozymes are then analyzed, followed by summarizing their biomedical applications. Finally, the challenges and opportunities in this field are outlined. This review article aims to provide theoretical guidance for developing Pt nanozymes with robust functionalities in biomedical applications.

Metallic nanoparticles unveiled: Synthesis, characterization, and their environmental, medicinal, and agricultural applications

Metallic nanoparticles (MNPs) have attracted great interest among scientists and researchers for years due to their unique optical, physiochemical, biological, and magnetic properties. As a result, MNPs have been widely utilized across a variety of scientific fields, including biomedicine, agriculture, electronics, food, cosmetics, and the environment. In this regard, the current review article offers a comprehensive overview of recent studies on the synthesis of MNPs (metal and metal oxide nanoparticles), outlining the benefits and drawbacks of chemical, physical, and biological methods. However, the biological synthesis of MNPs is of great importance considering the biocompatibility and biological activity of certain MNPs. A variety of characterization techniques, including X-ray diffraction, transmission electron microscopy, UV-visible spectroscopy, scanning electron microscopy, dynamic light scattering, atomic force microscopy, Fourier transform infrared spectroscopy, and others, have been discussed in depth to gain deeper insights into the unique structural and spectroscopic properties of MNPs. Furthermore, their unique properties and applications in the fields of medicine, agriculture, and the environment are summarized and deeply discussed. Finally, the main challenges and limitations of MNPs synthesis and applications, as well as their future prospects have also been discussed.

Unlocking the Potential of Phyto Nanotherapeutics in Hepatocellular Carcinoma Treatment: A Review

Hepatocellular carcinoma is the fifth leading cancer in related diseases most commonly in men and women. The curative treatments of liver cancer are short-listed, associated with toxicities and therapeutically. Emerging nanotechnologies exhibited the possibility to treat or target liver cancer. Over the years, to phytosome solid lipid nanoparticles, gold, silver, liposomes, and phospholipid nanoparticles have been produced for liver cancer therapy, and some evidence of their effectiveness has been established. Ideas are limited to the laboratory scale, and in order to develop active targeting of nanomedicine for the clinical aspects, they must be extended to a larger scale. Thus, the current review focuses on previously and presently published research on the creation of phytosomal nanocarriers for the treatment of hepatocellular carcinoma. In hepatocellular carcinoma (HCC), phytosomal nanotherapeutics improve the targeted delivery and bioavailability of phytochemicals to tumor cells, thereby reducing systemic toxicity and increasing therapeutic efficacy. In order to address the intricate molecular processes implicated in HCC, this strategy is essential.

Eco-synthesis of green silver nanoparticles using natural extracts and its application as co-catalyst in photocatalytic hydrogen production

Green silver nanoparticles (AgNPs) were synthesized using natural extracts as reducing agents and were firstly applied as co-catalysts in low-intensity-visible-light driven photocatalytic hydrogen production (PH2P), which a solution for green energy sources and independence from fossil fuels. The as-prepared AgNPs possessed size in a few tens nanometers and exhibited surface plasmon resonance (SPR) effects in the 310-560 nm region. Depositing AgNPs on g-C3N4 nanosheets broadened the visible absorption range, reduced electron-hole recombination, and increased electronic communication at the interface. g-C3N4/Ag demonstrated high PH2P efficiency, stability over three consecutive cycles, and a rapidly rising photocurrent under low-intensity visible light irradiation, although these features were not observed in g-C3N4 alone. The H2 evolution of g-C3N4/Ag_CC (CC: Cinnamomum camphora), g-C3N4/Ag_GT (GT: green tea), and g-C3N4/Ag_PP (PP: pomelo peels) reached 252.6, 125.3 and 92.0 μmol g-1 at 180 min at the first cycle, respectively. Among them, g-C3N4/Ag_CC showed the highest photocatalytic activity, which may be attributed to the superior morphology, optical properties of AgNPs_CC, and efficient electron transfer from g-C3N4 to AgNPs_CC. The SPR effect and Schottky barriers formed at the interface could contribute to enhancing the overall efficiency of the heterojunction photocatalysts. The results highlighted a crucial advancement toward H2 production under low-intensity visible-light irradiation.

Platinum Group Metals Nanoparticles in Breast Cancer Therapy

Despite various methods currently used in cancer therapy, breast cancer remains the leading cause of morbidity and mortality worldwide. Current therapeutics face limitations such as multidrug resistance, drug toxicity and off-target effects, poor drug bioavailability and biocompatibility, and inefficient drug delivery. Nanotechnology has emerged as a promising approach to cancer diagnosis, imaging, and therapy. Several preclinical studies have demonstrated that compounds and nanoparticles formulated from platinum group metals (PGMs) effectively treat breast cancer. PGMs are chemically stable, easy to functionalise, versatile, and tunable. They can target hypoxic microenvironments, catalyse the production of reactive oxygen species, and offer the potential for combination therapy. PGM nanoparticles can be incorporated with anticancer drugs to improve efficacy and can be attached to targeting moieties to enhance tumour-targeting efficiency. This review focuses on the therapeutic outcomes of platinum group metal nanoparticles (PGMNs) against various breast cancer cells and briefly discusses clinical trials of these nanoparticles in breast cancer treatment. It further illustrates the potential applications of PGMNs in breast cancer and presents opportunities for future PGM-based nanomaterial applications in combatting breast cancer.

An Outlook on Platinum-Based Active Ingredients for Dermatologic and Skincare Applications

Platinum-based materials exhibit a broad spectrum of biological activities, including antioxidant, anti-inflammatory, antimicrobial, and pro-collagen synthesis properties, making them particularly useful for various biomedical applications. This review summarizes the biological effects and therapeutic potential of platinum-based active ingredients in dermatological and skincare applications. We discuss their synthesis methods and their antioxidant, anti-inflammatory, antimicrobial, and collagen synthesis properties, which play essential roles in treating skin conditions including psoriasis and acne, as well as enhancing skin aesthetics in anti-aging products. Safety and sustainability concerns, including the need for green synthesis and comprehensive toxicological assessments to ensure safe topical applications, are also discussed. By providing an up-to-date overview of current research, we aim to highlight both the potential and the current challenges of platinum-based active ingredients in advancing dermatology and skincare solutions.

Exploring the Biomedical Frontiers of Plant-Derived Nanoparticles: Synthesis and Biological Reactions

As contemporary technology advances, scientists are striving to identify new approaches to managing several diseases. Compared to the more popular physiochemical synthesis, the plant-derived combination of metallic nanoparticles using plant secondary metabolites as a precursor has a number of benefits, including low expenses, low energy consumption, biocompatibility, and medicinal usefulness. This study intends to explore the impacts of using plant-derived synthetic materials including metallic nanoparticles (NPs), emphasizing the benefits of their broad use in next-generation treatments for cancer, diabetes, Alzheimer's, and vector diseases. This comprehensive analysis investigates the potential of plant-derived remedies for diseases and looks at cutting-edge nanoformulation techniques aimed at addressing the function of the nanoparticles that accompany these organic substances. The purpose of the current review is to determine how plant extracts contribute to the synthesis of Silver nanoparticles (AgNPs), Gold nanoparticles (GtNPs), and platinum nanoparticles (PtNPs). It provides an overview of the many phytocompounds and their functions in biomedicine, including antibacterial, antioxidant, anticancer, and anti-inflammatory properties. Furthermore, this study placed a special focus on a range of applications, including drug delivery systems, diagnostics and therapy, the present benefits of nanoparticles (NPs), their biomedical uses in medical technology, and their toxicities.

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.

Recent Trends in Biologically Synthesized Metal Nanoparticles and their Biomedical Applications: a Review

In recent years, biologically synthesized metal nanoparticles have emerged as a dynamic field of research with significant implications for biomedical applications. This review explores the latest trends in the synthesis of metal nanoparticles using biological methods, encompassing plant extracts and microorganisms such as bacteria, yeasts, and fungi. These innovative approaches offer a sustainable, cost-effective, and environmentally friendly alternative to conventional chemical synthesis methods. Moreover, this review delves into the multifaceted biomedical applications of biologically synthesized metal nanoparticles. These applications include drug delivery systems, diagnostics, therapeutics, and imaging technologies, showcasing the versatility and promise of these nanomaterials in addressing contemporary biomedical challenges. In addition, the review addresses the critical issue of cytotoxicity, offering insights into the safety and viability of these biologically derived NPs for medical use. The exploration of recent trends and advancements in this field underscores the transformative potential of biologically synthesized metal nanoparticles in revolutionizing biomedical research and healthcare.

Green biologically synthesized metal nanoparticles: biological applications, optimizations and future prospects

In green biological synthesis, metal nanoparticles are produced by plants or microorganisms. Since it is ecologically friendly, economically viable and sustainable, this method is preferable to other traditional ones. For their continuous groundbreaking advancements and myriad physiochemical and biological benefits, nanotechnologies have influenced various aspects of scientific fields. Metal nanoparticles (MNPs) are the field anchor for their outstanding optical, electrical and chemical capabilities that outperform their regular-sized counterparts. This review discusses the most current biosynthesized metal nanoparticles synthesized by various organisms and their biological applications along with the key elements involved in MNP green synthesis. The review is displayed in a manner that will impart assertiveness, help the researchers to open questions, and highlight many points for conducting future research.

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.

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.

Green Extracts with Metal-based Nanoparticles for Treating Inflammatory Diseases: A Review

Globally, high death rates and poor quality of life are caused mainly by inflammatory diseases. Corticosteroids, which may have systemic side effects and would enhance the risk of infection, are the common forms of therapy. The field of nanomedicine has created composite nanoparticles that carry a pharmacological carrier and target ligands for distribution to sites of inflammation with less systemic toxicity. However, their relatively large size often causes systemic clearance. An interesting approach is metal-based nanoparticles that naturally reduce inflammation. They are made not only to be small enough to pass through biological barriers but also to allow label-free monitoring of their interactions with cells. The following literature review discusses the mechanistic analysis of the anti-inflammatory properties of several metal-based nanoparticles, including gold, silver, titanium dioxide, selenium, and zinc oxide. Current research focuses on the mechanisms by which nanoparticles infiltrate cells and the anti-inflammatory techniques using herbal extracts-based nanoparticles. Additionally, it provides a brief overview of the literature on many environmentally friendly sources employed in nanoparticle production and the mechanisms of action of various nanoparticles.

Role of the Human Serum Albumin Protein Corona in the Antimicrobial and Photothermal Activity of Metallic Nanoparticles against Escherichia coli Bacteria

The emergence of antibiotic-resistant bacteria has become a major public health concern, leading to growing interest in alternative antimicrobial agents. The antibacterial activity of metal nanoparticles (NPs) has been extensively studied, showing that they can effectively inhibit the growth of various bacteria, including both Gram-positive and -negative strains. The presence of a protein corona, formed by the adsorption of proteins onto the NP surface in biological fluids, can significantly affect their toxicity. Understanding the effect of the protein corona on the antimicrobial activity of metal NPs is crucial for their effective use as antimicrobial agents. In this study, the antimicrobial activity of noble metal NPs, such as platinum (Pt), silver (Ag), and gold (Au) with and without the human serum albumin (HSA) protein corona against Escherichia coli strains, was investigated. In addition, the plasmonic photothermal effect related to AuNPs, which resulted to be the most biocompatible compared to the other considered metals, was evaluated. The obtained results suggest that the HSA protein corona modulated the antimicrobial activity exerted by the metal NPs against E. coli bacteria. These findings may pave the way for the investigation and development of innovative nanoapproaches to face antibiotic resistance emergence.

Green and sustainable synthesis of nanomaterials: Recent advancements and limitations

Nanomaterials have been widely used in diverse fields of research such as engineering, biomedical science, energy, and environment. At present, chemical and physical methods are the main methods for large-scale synthesis of nanomaterials, but these methods have adverse effects on the environment, and health issues, consume more energy, and are expensive. The green synthesis of nanoparticles is a promising and environmentally friendly approach to producing materials with unique properties. Natural reagents such as herbs, bacteria, fungi, and agricultural waste are used in the green synthesis of nanomaterials instead of hazardous chemicals and reduce the carbon footprint of the synthesis process. Green synthesis of nanomaterials is highly beneficial compared to traditional methods due to its low cost, negligible pollution level, and safety for the environment and human health. Nanoparticles possess enhanced thermal and electrical conductivity, catalytic activity, and biocompatibility, making them highly attractive for a range of applications, including catalysis, energy storage, optics, biological labeling, and cancer therapy. This review article provides a comprehensive overview of recent advancements in the green synthesis routes of different types of nanomaterials, including metal oxide-based, inert metal-based, carbon-based, and composite-based nanoparticles. Moreover, we discuss the various applications of nanoparticles, emphasizing their potential to revolutionize fields such as medicine, electronics energy, and the environment. The factors affecting the green synthesis of nanomaterials, and their limitations are also pointed out to decide the direction of this research field, Overall, this paper highlights the importance of green synthesis in promoting sustainable development in various industries.

One-pot green synthesis of silver nanoparticles using brittle star Ophiocoma scolopendrina: Assessing biological potentialities of antibacterial, antioxidant, anti-diabetic and catalytic degradation of organic dyes

In the current study, aqueous extract of O. scolopendrina (OSE) was used to synthesize AgNPs in a simple and environmentally friendly manner. The biosynthesized OSE-AgNPs were also assessed for its catalytic, antibacterial, anti-diabetic, antioxidant and dye degradation properties. The techniques like UV-visible spectroscopic examinations, TEM, SEM, TGA, zeta potential and FT-IR were used in the characterization investigations. The bioproduction of OSE-AgNPs was preliminary confirmed by UV-visible spectroscopic based investigation followed by microscopic visualization. The synthesized OSE-AgNPs exhibited a reddish brown colour and nearly spherical forms with sizes between 5 and 50 nm quantified by TEM and SEM. The attendance of functional groups like -OH and -NH present in OSE caps on the AgNPs surface was confirmed by FTIR analysis. Interestingly, in the presence of OSE-AgNPs, the degradation of dyes (CV, 95% and EY, 96% in 15 min) were noticeably accelerated. Further, OSE-AgNPs demonstrated substantial antibacterial activity; robust antioxidant properties andnotable anti-diabetic activities. This is the first account on the biosynthetic process of AgNPs using the aqueous extract of O. scolopendrina.

Scaling-up strategies for controllable biosynthetic ZnO NPs using cell free-extract of endophytic Streptomyces albus: characterization, statistical optimization, and biomedical activities evaluation

In this study, we identified a suitable precursor and good cellular compartmentalization for enhancing bioactive metabolites to produce biosynthetic zinc oxide nanoparticles (ZnO NPs). An effective medium for cultivating endophytic Streptomyces albus strain E56 was selected using several optimized approaches in order to maximize the yield of biosynthetic ZnO NPs. The highest biosynthetic ZnO NPs yield (4.63 g/L) was obtained when pipetting the mixed cell-free fractions with 100 mM of zinc sulfate as a precursor. The generation of biosynthetic ZnO NPs was quickly verified using a colored solution (white color) and UV-Visible spectroscopy (maximum peak, at 320 nm). On a small scale, the Taguchi method was applied to improve the culture medium for culturing the strain E56. As a result, its cell-dry weight was 3.85 times that of the control condition. And then the biosynthesis of ZnO NPs (7.59 g/L) was increased by 1.6 times. Furthermore, by using the Plackett-Burman design to improve the utilized biogenesis pathway, the biosynthesis of ZnO NPs (18.76 g/L) was increased by 4.3 times. To find the best growth production line, we used batch and fed batch fermentation modes to gradually scale up biomass output. All kinetics of studied cell growth were evaluated during fed-batch fermentation as follows: biomass yield was 271.45 g/L, yield coefficient was 94.25 g/g, and ZnO NPs yield was 345.32 g/L. In vitro, the effects of various dosages of the controllable biosynthetic ZnO NPs as antimicrobial and anticancer agents were also investigated. The treatments with controllable biosynthetic ZnO NPs had a significant impact on all the examined multidrug-resistant human pathogens as well as cancer cells.

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.

Green Synthesis of Platinum Nanoparticles for Biomedical Applications

The diverse biological properties of platinum nanoparticles (PtNPs) make them ideal for use in the development of new tools in therapy, diagnostics, and other biomedical purposes. "Green" PtNPs synthesis is of great interest as it is eco-friendly, less energy-consuming and minimizes the amount of toxic by-products. This review is devoted to the biosynthesis properties of platinum nanoparticles based on living organisms (bacteria, fungi, algae, and plants) use. The participation of various biological compounds in PtNPs synthesis is highlighted. The biological activities of "green" platinum nanoparticles (antimicrobial, anticancer, antioxidant, etc.), the proposed mechanisms of influence on target cells and the potential for their further biomedical application are discussed.

Biomedical Applications of Plant Extract-Synthesized Silver Nanoparticles

Silver nanoparticles (AgNPs) have attracted a lot of interest directed towards biomedical applications due in part to their outstanding anti-microbial activities. However, there have been many health-impacting concerns about their traditional synthesis methods, i.e., the chemical and physical methods. Chemical methods are commonly used and contribute to the overall toxicity of the AgNPs, while the main disadvantages of physical synthesis include high production costs and high energy consumption. The biological methods provide an economical and biocompatible option as they use microorganisms and natural products in the synthesis of AgNPs with exceptional biological properties. Plant extract-based synthesis has received a lot of attention and has been shown to resolve the limitations associated with chemical and physical methods. AgNPs synthesized using plant extracts provide a safe, cost-effective, and environment-friendly approach that produces biocompatible AgNPs with enhanced properties for use in a wide range of applications. The review focused on the use of plant-synthesized AgNPs in various biomedical applications as anti-microbial, anti-cancer, anti-inflammatory, and drug-delivery agents. The versatility and potential use of green AgNPs in the bio-medicinal sector provides an innovative alternative that can overcome the limitations of traditional systems. Thus proving green nanotechnology to be the future for medicine with continuous progress towards a healthier and safer environment by forming nanomaterials that are low- or non-toxic using a sustainable approach.

Advances in Antitumor Nano-Drug Delivery Systems of 10-Hydroxycamptothecin

10-Hydroxycamptothecin (HCPT) is a natural plant alkaloid from Camptotheca that shows potent antitumor activity by targeting intracellular topoisomerase I. However, factors such as instability of the lactone ring and insolubility in water have limited the clinical application of this drug. In recent years, unprecedented advances in biomedical nanotechnology have facilitated the development of nano drug delivery systems. It has been found that nanomedicine can significantly improve the stability and water solubility of HCPT. NanoMedicines with different diagnostic and therapeutic functions have been developed to significantly improve the anticancer effect of HCPT. In this paper, we collected reports on HCPT nanomedicines against tumors in the past decade. Based on current research advances, we dissected the current status and limitations of HCPT nanomedicines development and looked forward to future research directions.

Innovative Insights into In Vitro Activity of Colloidal Platinum Nanoparticles against ESBL-Producing Strains of Escherichia coli and Klebsiella pneumoniae

Growing morbidity and mortality rates due to increase in the number of infections caused by MDR (multi-drug resistant) microorganisms are becoming some of the foremost global health issues. Thus, the need to search for and find novel approaches to fight AMR (antimicrobial resistance) has become obligatory. This study aimed to determine the antimicrobial properties of commercially purchased colloidal platinum nanoparticles by examining the existence and potency of their antibacterial effects and investigating the mechanisms by means of which they express these activities. Antimicrobial properties were investigated with respect to standard laboratory ATCC (American Type Cell Culture) and clinical extended-spectrum beta-lactamase (ESBL)-producing strains of Escherichia (E.) coli and Klebsiella (K.) pneumoniae. Standard microbiological methods of serial microdilution, modulation of microbial cell death kinetics (“time–kill” assays), and biofilm inhibition were used. Bacterial cell wall damage and ROS (reactive oxygen species) levels were assessed in order to explore the mechanisms of platinum nanoparticles’ antibacterial activities. Platinum nanoparticles showed strong antibacterial effects against all tested bacterial strains, though their antibacterial effects were found to succumb to time kinetics. Antibiofilm activity was modest overall and significantly effective only against E. coli strains. By measuring extracellular DNA/RNA and protein concentrations, induced bacterial cell wall damage could be assumed. The determination of ROS levels induced by platinum nanoparticles revealed their possible implication in antibacterial activity. We conclude that platinum nanoparticles exhibit potent antibacterial effects against standard laboratory and resistant strains of E. coli and K. pneumoniae. Both, cell wall damage and ROS induction could have important role as mechanisms of antibacterial activity, and, require further investigation.

Green Nanotechnology: Recent Research on Bioresource-Based Nanoparticle Synthesis and Applications

In the last decades, the idea of green nanotechnology has been expanding, and researchers are developing greener and more sustainable techniques for synthesizing nanoparticles (NPs). The major objectives are to fabricate NPs using simple, sustainable, and cost-effective procedures while avoiding the use of hazardous materials that are usually utilized as reducing or capping agents. Many biosources, including plants, bacteria, fungus, yeasts, and algae, have been used to fabricate NPs of various shapes and sizes. The authors of this study emphasized the most current studies for fabricating NPs from biosources and their applications in a wide range of fields. This review addressed studies that cover green techniques for synthesizing nanoparticles of Ag, Au, ZnO, CuO, Co3O4, Fe3O4, TiO2, NiO, Al2O3, Cr2O3, Sm2O3, CeO2, La2O3, and Y2O3. Also, their applications were taken under consideration and discussed.

Silver nanostructures prepared via novel green approach as an effective platform for biological and environmental applications

Silver nanoparticles play a significant role in biomedical sciences due to their unique properties allowing for their use as an effective sensing and remediation platform Herein, the green synthesis of silver nanostructures (Ag NSs), prepared via aqueous extract of waste Brassica oleracea leaves in the presence of silver nitrate solution (10-4 M), is reported. The Ag NSs are fully characterized and their efficacy with respect to 4-nitrophenol reduction, glucose sensing, and microbes is determined. Visually, the color of silver nitrate containing solution altered from colorless to yellowish, then reddish grey, confirming the formation of Ag NSs. HRTEM and SEAD studies revealed the Ag NSs to have different morphologies (triangular, rod-shaped, hexagonal, etc., within a size range of 20-40 nm) with face-centered cubic (fcc) crystal structure. The Ag NSs possess high efficacy for nitrophenol reduction (<11 min and degradation efficiency of 98.2%), glucose sensing (LOD: 5.83 µM), and antimicrobial activity (E. coli and B. subtilis with clearance zones of 18.3 and 14 mm, respectively). Thus, the current study alludes towards the development of a cost-effective, sustainable, and efficient three-in-one platform for biomedical and environmental applications.

Methods for Green Synthesis of Metallic Nanoparticles Using Plant Extracts and their Biological Applications - A Review

Nanotechnology, a fast-developing branch of science, is gaining extensive popularity among researchers simply because of the multitude of applications it can offer. In recent years, biological synthesis has been widely used instead of physical and chemical synthesis methods, which often produce toxic products. These synthesis methods are now being commonly adapted to discover new applications of nanoparticles synthesized using plant extracts. In this review, we elucidate the various ways by which nanoparticles can be biologically synthesized. We further discuss the applications of these nanoparticles.

Platinum Nanoparticles: The Potential Antioxidant in the Human Lung Cancer Cells

Oxidative stress-related conditions associated with lung cells, specifically lung cancer, often lead to a poor prognosis. We hypothesized that platinum nanoparticles (PtNPs) can play a role in reversing oxidative stress in human lung adenocarcinoma A549 epithelial lung cell lines. Hydrogen peroxide (H₂O₂) was used to induce oxidative stress in cells, and the ability of PtNPs to lower the oxidative stress in the H₂O₂ treated epithelial lung cell line was determined. The differential capacity of PtNPs to remove H₂O₂ was studied through cell viability, nanoparticle uptake, DNA damage, ROS production, and antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). Results indicated that a higher concentration of PtNPs exhibited a higher antioxidant capacity and was able to reduce DNA damage and quench ROS production in the presence of 350 µM H₂O₂. All antioxidant enzymes’ activities also increased in the PtNPs treatment. Our data suggested that PtNPs could be a promising antioxidant in the treatment of lung cancer.

Recent Advances in Green Synthesis of Ag NPs for Extenuating Antimicrobial Resistance

Combating antimicrobial resistance (AMR) is an on-going global grand challenge, as recognized by several UN Sustainable Development Goals. Silver nanoparticles (Ag NPs) are well-known for their efficacy against antimicrobial resistance, and a plethora of green synthesis methodologies now exist in the literature. Herein, this review evaluates recent advances in biological approaches for Ag NPs, and their antimicrobial potential of Ag NPs with mechanisms of action are explored deeply. Moreover, short and long-term potential toxic effects of Ag NPs on animals, the environment, and human health are briefly discussed. Finally, we also provide a summary of the current state of the research and future challenges on a biologically mediated Ag-nanostructures-based effective platform for alleviating AMR.

Platinum Nanoparticles in Biomedicine: Preparation, Anti-Cancer Activity, and Drug Delivery Vehicles

Cancer is the main cause of morbidity and mortality worldwide, excluding infectious disease. Because of their lack of specificity in chemotherapy agents are used for cancer treatment, these agents have severe systemic side effects, and gradually lose their therapeutic effects because most cancers become multidrug resistant. Platinum nanoparticles (PtNPs) are relatively new agents that are being tested in cancer therapy. This review covers the various methods for the preparation and physicochemical characterization of PtNPs. PtNPs have been shown to possess some intrinsic anticancer activity, probably due to their antioxidant action, which slows tumor growth. Targeting ligands can be attached to functionalized metal PtNPs to improve their tumor targeting ability. PtNPs-based therapeutic systems can enable the controlled release of drugs, to improve the efficiency and reduce the side effects of cancer therapy. Pt-based materials play a key role in clinical research. Thus, the diagnostic and medical industries are exploring the possibility of using PtNPs as a next-generation anticancer therapeutic agent. Although, biologically prepared nanomaterials exhibit high efficacy with low concentrations, several factors still need to be considered for clinical use of PtNPs such as the source of raw materials, stability, solubility, the method of production, biodistribution, accumulation, controlled release, cell-specific targeting, and toxicological issues to human beings. The development of PtNPs as an anticancer agent is one of the most valuable approaches for cancer treatment. The future of PtNPs in biomedical applications holds great promise, especially in the area of disease diagnosis, early detection, cellular and deep tissue imaging, drug/gene delivery, as well as multifunctional therapeutics.

Enhanced Anticancer Activity of Nedaplatin Loaded onto Copper Nanoparticles Synthesized Using Red Algae

Marine algae are a rich source of biologically active compounds that can be utilized in various food and pharmaceutical applications. In this study, ultrasound-assisted extraction (UAE) was optimized to maximize yield and total carbohydrate content extracted from the red algae, Pterocladia capillacea. The extract was shown to possess potent antioxidant activity of up to ~70%, and was successfully used as a reducing and capping agent in the green synthesis of copper nanoparticles, which were characterized by UV-spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Primarily, CuO nanoparticles with an average size of 62 nm were produced. FTIR spectra for the extract and algal-mediated CuO nanoparticles showed characteristic polysaccharide peaks. The synthesized CuO nanoparticles were subsequently loaded with nedaplatin where UV data suggested a complex formation. Nedaplatin release profiles showed a sustained release that reached a maximum at 120 h. The formulation was shown to have greater cytotoxicity relative to nedaplatin on hepatocellular carcinoma, breast cancer and ovarian cancer cell lines with IC50 values of 0.40 ± 0.08, 1.50 ± 0.12, and 0.70 ± 0.09 µg/mL, respectively. Loading nedaplatin onto CuO nanoparticles synthesized using red algae extract, greatly enhances its anticancer effect.

Biocompatibility of Platinum Nanoparticles in Brain ex vivo Models in Physiological and Pathological Conditions

Platinum nanoparticles (PtNPs) have unique physico-chemical properties that led to their use in many branches of medicine. Recently, PtNPs gathered growing interest as delivery vectors for drugs, biosensors and as surface coating on chronically implanted biomedical devices for improving electrochemical properties. However, there are contradictory statements about their biocompatibility and impact on target organs such as the brain tissue, where these NPs are finding many applications. Furthermore, many of the reported studies are conducted in homeostasis conditions and, consequently, neglect the impact of the pathologic conditions on the tissue response. To expand our knowledge on the effects of PtNPs on neuronal and glial cells, we investigated the acute effects of monodisperse sodium citrate-coated PtNPs on rat organotypic hippocampal cultures in physiological or neuronal excitotoxic conditions induced by kainic acid (KA). The cellular responses of the PtNPs were evaluated through cytotoxic assays and confocal microscopy analysis. To mimic a pathologic scenario, 7-day organotypic hippocampal cultures were exposed to KA for 24 h. Subsequently, PtNPs were added to each slice. We show that incubation of the slices with PtNPs for 24 h, does not severely impact cell viability in normal conditions, with no significant differences when comparing the dentate gyrus (DG), as well as CA3 and CA1 pyramidal cell layers. Such effects are not exacerbated in KA-treated slices, where the presence of PtNPs does not cause additional neuronal propidium iodide (PI) uptake in CA3 and CA1 pyramidal cell layers. However, PtNPs cause microglial cell activation and morphological alterations in CA3 and DG regions indicating the establishment of an inflammatory reaction. Morphological analysis revealed that microglia acquire activated ameboid morphology with loss of ramifications, as a result of their response to PtNPs contact. Surprisingly, this effect is not increased in pathological conditions. Taken together, these results show that PtNPs cause microglia alterations in short-term studies. Additionally, there is no worsening of the tissue response in a neuropathological induced scenario. This work highlights the need of further research to allow for the safe use of PtNPs. Also, it supports the demand of the development of novel and more biocompatible NPs to be applied in the brain.

Chitosan-Coated PLGA Nanoparticles Loaded with Peganum harmala Alkaloids with Promising Antibacterial and Wound Healing Activities

Wound healing is a major healthcare concern, and complicated wounds may lead to severe outcomes such as septicemia and amputations. To date, management choices are limited, which warrants the search for new potent wound healing agents. Natural products loaded in poly (lactic-co-glycolic acid) (PLGA) coated with chitosan (CS) constitute a promising antibacterial wound healing formulation. In this work, harmala alkaloid-rich fraction (HARF) loaded into PLGA nanoparticles coated with chitosan (H/CS/PLGA NPs) were designed using the emulsion-solvent evaporation method. Optimization of the formulation variables (HARF: PLGA and CS: PLGA weight ratios, sonication time) was performed using the 33 Box-Behnken design (BBD). The optimal NPs were characterized using transmission electron microscopy (TEM) and Attenuated Total Reflection Fourier-Transformed Infrared Spectroscopy (ATR-FTIR). The prepared NPs had an average particle size of 202.27 ± 2.44 nm, a PDI of 0.23 ± 0.01, a zeta potential of 9.22 ± 0.94 mV, and an entrapment efficiency of 86.77 ± 4.18%. In vitro drug release experiments showed a biphasic pattern where an initial burst of 82.50 ± 0.20% took place in the first 2 h, which increased to 87.50 ± 0.50% over 72 h. The designed optimal H/CS/PLGA NPs exerted high antibacterial activity against Staphylococcus aureus and Escherichia coli (MIC of 0.125 and 0.06 mg/mL, respectively) compared to unloaded HARF (MIC of 0.50 mg/mL). The prepared nanoparticles were found to be biocompatible when tested on human skin fibroblasts. Moreover, the wound closure percentage after 24 h of applying H/CS/PLGA NPs was found to be 94.4 ± 8.0%, compared to free HARF and blank NPs (68.20 ± 5.10 and 50.50 ± 9.40%, respectively). In conclusion, the three components of the developed nanoformulation (PLGA, chitosan, and HARF) have synergistic antibacterial and wound healing properties for the management of infected wounds.

Biosynthesis of Selenium Nanoparticles (via Bacillus subtilis BSN313), and Their Isolation, Characterization, and Bioactivities

Among the trace elements, selenium (Se) has great demand as a health supplement. Compared to its other forms, selenium nanoparticles have minor toxicity, superior reactivity, and excellent bioavailability. The present study was conducted to produce selenium nanoparticles (SeNPs) via a biosynthetic approach using probiotic Bacillus subtilis BSN313 in an economical and easy manner. The BSN313 exhibited a gradual increase in Se reduction and production of SeNPs up to 5-200 µg/mL of its environmental Se. However, the capability was decreased beyond that concentration. The capacity for extracellular SeNP production was evidenced by the emergence of red color, then confirmed by a microscopic approach. Produced SeNPs were purified, freeze-dried, and subsequently characterized systematically using UV-Vis spectroscopy, FTIR, Zetasizer, SEM-EDS, and TEM techniques. SEM-EDS analysis proved the presence of selenium as the foremost constituent of SeNPs. With an average particle size of 530 nm, SeNPs were shown to have a -26.9 (mV) zeta potential and -2.11 µm cm/Vs electrophoretic mobility in water. SeNPs produced during both the 24 and 48 h incubation periods showed good antioxidant activity in terms of DPPH and ABST scavenging action at a concentration of 150 µg/mL with no significant differences (p > 0.05). Moreover, 200 µg/mL of SeNPs showed antibacterial reactivity against Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 9027, and Pseudomonas aeruginosa ATCC 25923. In the future, this work will be helpful to produce biogenic SeNPs using probiotic Bacillus subtilis BSN313 as biofactories, with the potential for safe use in biomedical and nutritional applications.

Biosynthesis and Cytotoxic Properties of Ag, Au, and Bimetallic Nanoparticles Synthesized Using Lithospermum erythrorhizon Callus Culture Extract

The present study reports a green chemistry approach for the rapid and easy biological synthesis of silver (Ag), gold (Au), and bimetallic Ag/Au nanoparticles using the callus extract of Lithospermum erythrorhizon as a reducing and capping agent. The biosynthesized nanoparticles were characterized with ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD) analysis, and transmission electron microscopy (TEM). Our results showed the formation of crystalline metal nanostructures of both spherical and non-spherical shape. Energy dispersive X-ray (EDX) spectroscopy showed the characteristic peaks in the silver and gold regions, confirming the presence of the corresponding elements in the monometallic particles and both elements in the bimetallic particles. Fourier-transform infrared (FTIR) spectroscopy affirmed the role of polysaccharides and polyphenols of the L. erythrorhizon extract as the major reducing and capping agents for metal ions. In addition, our results showed that the polysaccharide sample and the fraction containing secondary metabolites isolated from L. erythrorhizon were both able to produce large amounts of metallic nanoparticles. The biosynthesized nanoparticles demonstrated cytotoxicity against mouse neuroblastoma and embryonic fibroblast cells, which was considerably higher for Ag nanoparticles and for bimetallic Ag/Au nanoparticles containing a higher molar ratio of silver. However, fibroblast migration was not significantly affected by any of the nanoparticles tested. The obtained results provide a new example of the safe biological production of metallic nanoparticles, but further study is required to uncover the mechanism of their toxicity so that the biomedical potency can be assessed.

Betaine host-guest complexation with a calixarene receptor: enhanced in vitro anticancer effect

p-Sulfonatocalix[n]arenes have shown excellent potential for accommodating chemotherapeutic drugs through host-guest complexation and enhancing their anticancer activity. Betaine has been reported to exert an anticancer effect at high concentrations. In order to increase its concentration in cancer cells, we have complexed it with p-SC4, which releases its content in an acidic environment typical of cancer tissue. In this work, a host-guest complex of the chemically stable, natural, and safe active methyl donor (betaine) and p-sulfonatocalix[4]arenes (p-SC4) was designed and characterized using 1H NMR, UV, Job's plot analysis, DFT calculations, and molecular modeling for use in cancer therapeutics. The peak amplitude of the prepared host-guest complexes was linearly proportional to the concentration of betaine in the range of 1.0 × 10-5 M-1 to 2.5 × 10-4 M-1. The reaction stoichiometry between p-SC4 and betaine in the formed complex was 1 : 1. The stability constant for the complex is 8.9 × 104 M-1 which corresponds to a complexation free energy of -6.74 kcal mol-1. Complexation between betaine and p-SC4 was found to involve the insertion of the trimethylammonium group of betaine into the p-SC4 cavity, as supported by the experimental data. The complex displayed enhanced cytotoxic activities against breast adenocarcinoma cells (MCF-7) and cervical cancer cells (HeLa) compared to free betaine. In conclusion, the host-guest complexation of betaine with p-SC4 increases its concentration in cancer cells, which warrants further investigation for cancer therapy.

Microbial Fabricated Nanosystems: Applications in Drug Delivery and Targeting

The emergence of nanosystems for different biomedical and drug delivery applications has drawn the attention of researchers worldwide. The likeness of microorganisms including bacteria, yeast, algae, fungi, and even viruses toward metals is well-known. Higher tolerance to toxic metals has opened up new avenues of designing microbial fabricated nanomaterials. Their synthesis, characterization and applications in bioremediation, biomineralization, and as a chelating agent has been well-documented and reviewed. Further, these materials, due to their ability to get functionalized, can also be used as theranostics i.e., both therapeutic as well as diagnostic agents in a single unit. Current article attempts to focus particularly on the application of such microbially derived nanoformulations as a drug delivery and targeting agent. Besides metal-based nanoparticles, there is enough evidence wherein nanoparticles have been formulated using only the organic component of microorganisms. Enzymes, peptides, polysaccharides, polyhydroxyalkanoate (PHA), poly-(amino acids) are amongst the most used biomolecules for guiding crystal growth and as a capping/reducing agent in the fabrication of nanoparticles. This has promulgated the idea of complete green chemistry biosynthesis of nano-organics that are most sought after in terms of their biocompatibility and bioavailability.

Green Synthesis of Platinum and Palladium Nanoparticles Using Peganum harmala L. Seed Alkaloids: Biological and Computational Studies

This study reports a facile and eco-friendly method for the green synthesis of platinum and palladium nanoparticles (Pt NPs and Pd NPs) using Peganum harmala seed alkaloid fraction. The ζ-potential of the synthesized Pt NPs, Pd NPs and Pt–Pd NPs were −11.2 ± 0.5, −9.7 ±1.2, and −12.7 ± 2.1 mV; respectively. Transmission electron microscopy (TEM) revealed the formation of spherical-shaped nanoparticles with smooth margins. The mean diameters of the synthesized Pt NPs, Pd NPs, and Pt–Pd NPs were determined using TEM analysis and were found to be 20.3 ± 1.9, 22.5 ± 5.7, and 33.5 ± 5.4 nm, respectively. The nanoparticles’ bioreduction was confirmed by ultraviolet–visible (UV–vis) spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, and their organic contents were determined by thermal gravimetric analysis (TGA). The Pt–Pd NPs mixture showed more pronounced antioxidant activity of 843.0 ± 60 μM Trolox equivalent (TE)/mg NPs compared to the individual Pt NPs (277.3 ± 13.5 μM TE/mg NPs) and Pd NPs (167.6 ± 4.8 μM TE/mg NPs). Furthermore, the Pt–Pd NPs exhibited significant cytotoxic activities against lung cancer (A549) and breast adenocarcinoma (MCF-7) cells, IC₅₀ of 8.8 and 3.6 µg/mL, respectively; as compared to Pt NPs (IC₅₀ of 10.9 and 6.7 µg/mL, respectively) and Pd NPs (IC₅₀ of 31 and 10.8 µg/mL, respectively and compared to carboplatin (IC₅₀ of 23 and 9.5 µg/mL, respectively). Moreover, molecular docking studies were conducted to explore the possible anticancer and antioxidant mechanisms of the biogenic nanoparticles. Pt NPs, Pd NPs, and their mixture showed inhibitory activity against cysteine proteinase, which supports their high antitumor activity, but moderate antioxidant activity. In conclusion, Pd-Pt NPs mixture prepared using harmala seed alkaloid fraction showed potential as effective antineoplastic agents.