Bioinspired and biomimetic micro- and nanostructures in biomedicine

Targeting lipid metabolism via nanomedicine: A prospective strategy for cancer therapy

Lipid metabolism has been increasingly recognized to play an influencing role in tumor initiation, progression, metastasis, and therapeutic drug resistance. Targeting lipid metabolic reprogramming represents a promising therapeutic strategy. Despite their structural complexity and poor targeting efficacy, lipid-metabolizing drugs, either used alone or in combination with chemotherapeutic agents, have been employed in clinical practice. The advent of nanotechnology offers new approaches to enhancing therapeutic effects, includingthe targeted delivery and integration of lipid metabolic reprogramming with chemotherapy, photodynamic therapy (PDT), and immunotherapy. The integrated nanoformulation, nanomedicine, could significantly advance the field of lipid metabolism therapy. In this review, we will briefly introduce the concept of cancer lipid metabolism reprogramming, then elaborate the latest advances in engineered nanomedicine for targeting lipid metabolism during cancer treatment, and finally provide our insights into future perspectives of nanomedicine for interference with lipid metabolism in the tumor microenvironment.

MXenes and MXene-based composites for biomedical applications

MXenes, a novel class of two-dimensional materials, have recently emerged as promising candidates for biomedical applications due to their specific structural features and exceptional physicochemical and biological properties. These materials, characterized by unique structural features and superior conductivity, have applications in tissue engineering, cancer detection and therapy, sensing, imaging, drug delivery, wound treatment, antimicrobial therapy, and medical implantation. Additionally, MXene-based composites, incorporating polymers, metals, carbon nanomaterials, and metal oxides, offer enhanced electroactive and mechanical properties, making them highly suitable for engineering electroactive organs such as the heart, skeletal muscle, and nerves. However, several challenges, including biocompatibility, functional stability, and scalable synthesis methods, remain critical for advancing their clinical use. This review comprehensively overviews MXenes and MXene-based composites, their synthesis, properties, and broad biomedical applications. Furthermore, it highlights the latest progress, ongoing challenges, and future perspectives, aiming to inspire innovative approaches to harnessing these versatile materials for next-generation medical solutions.

Efficacy and Cellular Mechanism of Biomimetic Marine Adhesive Protein-Based Coating Against Skin Photoaging

Skin photoaging is a problem worldwide, clinically often accompanied by collagen decline, increased wrinkles, loss of skin elasticity, structurally weakened skin, and other complications, which urgently demand effective treatment strategies. The biosafety and efficacy of single-function therapies for repairing skin photoaging are still challenging for clinical medicine today. At present, numerous studies report that the wet adhesive proteins driven from marine organisms play a critical role in the biomedical material field, particularly in aquatic environments. In this study, a natural recombinant protein-based coating from scallop byssal protein is prepared to investigate the efficacy and cellular mechanism in accelerating the repair of UVB-induced photoaging in a mouse model. In vitro experiments demonstrate the safety of the coating and its efficacy in enhancing cell adhesion, spreading, proliferation, and migration. Additionally, the coating effectively scavenges reactive oxygen species, promotes the expression of cell adhesion molecules and anti-apoptotic proteins, and inhibits inflammatory responses. In animal tests, the coating exhibited remarkable adsorption properties, showing significant potential for in situ regenerative therapy, as evidenced by its ability to protect against UVB-induced skin photoaging and oxidative stress. These findings suggest that Sbp9Δ coating provides a simple, safe, and innovative strategy for treating skin photoaging.

Apigenin as an emerging hepatoprotective agent: current status and future perspectives

Apigenin (C15H10O5, API) is a natural flavonoid widely found in vegetables, fruits, and plants such as celery, oranges, and chamomile. In recent years, API has attracted considerable attention as a dietary supplement due to its low toxicity, non-mutagenic properties and remarkable therapeutic efficacy in various diseases. In particular, evidence from a large number of preclinical studies suggests that API has promising effects in the prevention and treatment of a variety of liver diseases, including multifactorial liver injury, non-alcoholic fatty liver disease/non-alcoholic steatohepatitis, liver fibrosis and liver cancer. This paper provides a comprehensive review of the progress of research into the therapeutic applications of API in liver diseases as of August 2024, based on literature retrieved from databases such as Web of Science, PubMed, CNKI, Google Scholar and ScienceDirect. The hepatoprotective effects of API involve multiple molecular mechanisms, including inhibition of inflammation, alleviation of hepatic oxidative stress, amelioration of insulin resistance, promotion of fatty acid oxidation, inhibition of liver cancer cell proliferation and differentiation, and induction of tumour cell apoptosis. More importantly, signaling pathways such as Nrf2, NF-κB, PI3K/Akt/mTOR, NLRP3, Wnt/β-catenin, TGF-β1/Smad3, AMPK/SREBP, PPARα/γ, MAPKs, and Caspases are identified as key targets through which API exerts its beneficial effects in various liver diseases. Studies on its toxicity and pharmacokinetics indicate that API has low toxicity, is slowly metabolized and excreted in vivo, and has low oral bioavailability. In addition, the paper summarises and discusses the sources, physicochemical properties, new dosage forms, and current challenges and opportunities of API, with the aim of providing direction and rationale for the further development and clinical application of API in the food, pharmaceutical and nutraceutical fields.

Effect of Photolithographic Biomimetic Surface Microstructure on Wettability and Droplet Evaporation Process

In nature, engineering technology and daily life, wetting phenomena are widespread and have essential roles and significance. Bionics is becoming increasingly important nowadays and exploring the mechanism that influences biomimetic surface microstructure on droplet wetting process and heat and mass transfer characteristics is becoming more meaningful. In this paper, based on photolithography technology, SU-8 photoresist was used as raw material to prepare biomimetic surfaces with microstructures in various arrangements. The research results show that the wettability of biomimetic functional surfaces can be regulated by regulating the shape and arrangement of photoresist micro-pillars. At the same time, the effects of surface microstructure configuration and roughness on the heat and mass transfer processes within the droplets were also comprehensively studied. The results show that a biomimetic surface with cylindrical micro-pillars can effectively inhibit the evaporative cooling effect of the liquid-vapour interface. This effect becomes more evident with the increase in roughness, and the interface temperature difference can be reduced by up to 18%. Similarly, the biomimetic surface with cylindrical micro-pillars can also effectively promote the evaporation rate of sessile droplets, which can be increased by about 13%. In addition, the research also shows that regardless of the structure, substrate temperature changes will significantly impact the wetting phenomenon of the biomimetic surface. This study aims to guide the optimal design of biomimetic surfaces prepared based on photoresistance.

Nature-inspired innovations: unlocking the potential of biomimicry in bionanotechnology and beyond

Bionanotechnology research has surged to the forefront of scientific innovation, propelling the exploration of cutting-edge technologies and interdisciplinary collaboration. Biomimicry, which harnesses nature's ingenuity, drives the development of novel research-based solutions in diverse fields such as vaccines, medicine, and biomedical devices. Nature's role is becoming increasingly pivotal in addressing complex challenges related to environmental conservation, human health, and pandemic preparedness, including those posed by SARS-CoV-2 and other emerging pathogens. Progress in this domain encompasses understanding nature´s mechanisms to develop advanced materials inspired by biological structures. Biomimetic innovations have the potential to revolutionize industries, reduce environmental impacts, and facilitate a more harmonious relationship between humans and nature while considering bioethics, underlining the necessity of conducting responsible research and implementing biomimetic advancements conscientiously. As biomimicry continues to grow, integrating ethical guidelines and policies will ensure these nature-inspired technologies' sustainable development and application, ultimately contributing to a more resilient and adaptive society. This mini-review article broadly overviews bionanotechnology applications based on natural examples.

Bioinspired microrobots and their biomedical applications

Natural organisms and biological systems provide a rich source of inspiration for the development of bioinspired microrobots. These diminutive automatons, designed to emulate the intricate structures and functions of living entities, extend human capabilities across a spectrum of applications. This review endeavors to amalgamate and elucidate the underpinnings of such bioinspired microrobots design, traversing the interdisciplinary expanse of research. It delineates a spectrum of biomedical applications for bioinspired microrobots, encompassing targeted drug delivery, cellular manipulation, and minimally invasive surgical procedures, among others. Moreover, the current technical challenges and future directions of bioinspired microrobots in the biomedical field are discussed. The objective is to impart a holistic view to the readership, illuminating the significance of bioinspired microrobots in contemporary biomedicine and charting potential trajectories of innovation.

Nature-Inspired Wet Drug Delivery Platforms

Nature has created various organisms with unique chemical components and multi-scale structures (e.g., foot proteins, toe pads, suckers, setose gill lamellae) to achieve wet adhesion functions to adapt to their complex living environments. These organisms can provide inspirations for designing wet adhesives with mediated drug release behaviors in target locations of biological surfaces. They exhibit conformal and enhanced wet adhesion, addressing the bottleneck of weaker tissue interface adhesion in the presence of body fluids. Herein, it is focused on the research progress of different wet adhesion and bioinspired fabrications, including adhesive protein-based adhesion and inspired adhesives (e.g., mussel adhesion); capillarity and Stefan adhesion and inspired adhesive surfaces (e.g., tree frog adhesion); suction-based adhesion and inspired suckers (e.g., octopus' adhesion); interlocking and friction-based adhesion and potential inspirations (e.g., mayfly larva and teleost adhesion). Other secreted protein-induced wet adhesion is also reviewed and various suckers for other organisms and their inspirations. Notably, one representative application scenario of these bioinspired wet adhesives is highlighted, where they function as efficient drug delivery platforms on target tissues and/or organs with requirements of both controllable wet adhesion and optimized drug release. Finally, the challenges of these bioinspired wet drug delivery platforms in the future is presented.

Peptide functionalized biomimetic gene complexes enhance specificity for vascular endothelial regeneration

Gene delivery presents great potential in endothelium regeneration and prevention of vascular diseases, but its outcome is inevitably limited by high shear stress and instable microenvironment. Highly efficient nanosystems may alleviate the problem with strong dual-specificity for diseased site and targeted cells. Hence, biomimetic coatings incorporating EC-targeting peptides were constructed by platelets and endothelial cells (ECs) for surface modification. A series of biomimetic gene complexes were fabricated by the biomimetic coatings to deliver pcDNA3.1-VEGF165 plasmid (pVEGF) for rapid recovery of endothelium. The gene complexes possessed good biocompatibility with macrophages, stability with serum and showed no evident cytotoxicity for ECs even at very high concentrations. Furthermore, the peptide modified gene complexes achieved selective internalization in ECs and significant accumulation in endothelium-injured site, especially the REDV-modified and EC-derived gene complexes. They substantially enhanced VEGF expression at mRNA and protein levels, thereby enabling a wound to heal completely within 24 h according to wound healing assay. In an artery endothelium-injured mouse model, the REDV-modified and EC-derived gene complexes presented efficient re-endothelialization with the help of enhanced specificity. The biomimetic gene complexes offer an efficient dual-targeting strategy for rapid recovery of endothelium, and hold potential in vascular tissue regeneration.

Advanced Bioinspired Multifunctional Platforms Focusing on Gut Microbiota Regulation

Gut microbiota plays a crucial role in maintaining host homeostasis, impacting the progression and therapeutic outcomes of diseases, including inflammatory bowel disease, cancer, hepatic conditions, obesity, cardiovascular pathologies, and neurologic disorders, via immune, neural, and metabolic mechanisms. Hence, the gut microbiota is a promising target for disease therapy. The safety and precision of traditional microbiota regulation methods remain a challenge, which limits their widespread clinical application. This limitation has catalyzed a shift toward the development of multifunctional delivery systems that are predicated on microbiota modulation. Guided by bioinspired strategies, an extensive variety of naturally occurring materials and mechanisms have been emulated and harnessed for the construction of platforms aimed at the monitoring and modulation of gut microbiota. This review outlines the strategies and advantages of utilizing bioinspired principles in the design of gut microbiota intervention systems based on traditional regulation methods. Representative studies on the development of bioinspired therapeutic platforms are summarized, which are based on gut microbiota modulation to confer multiple pharmacological benefits for the synergistic management of diseases. The prospective avenues and inherent challenges associated with the adoption of bioinspired strategies in the refinement of gut microbiota modulation platforms are proposed to augment the efficacy of disease treatment.

Cancer Nanovaccines: Nanomaterials and Clinical Perspectives

Cancer nanovaccines represent a promising frontier in cancer immunotherapy, utilizing nanotechnology to augment traditional vaccine efficacy. This review comprehensively examines the current state-of-the-art in cancer nanovaccine development, elucidating innovative strategies and technologies employed in their design. It explores both preclinical and clinical advancements, emphasizing key studies demonstrating their potential to elicit robust anti-tumor immune responses. The study encompasses various facets, including integrating biomaterial-based nanocarriers for antigen delivery, adjuvant selection, and the impact of nanoscale properties on vaccine performance. Detailed insights into the complex interplay between the tumor microenvironment and nanovaccine responses are provided, highlighting challenges and opportunities in optimizing therapeutic outcomes. Additionally, the study presents a thorough analysis of ongoing clinical trials, presenting a snapshot of the current clinical landscape. By curating the latest scientific findings and clinical developments, this study aims to serve as a comprehensive resource for researchers and clinicians engaged in advancing cancer immunotherapy. Integrating nanotechnology into vaccine design holds immense promise for revolutionizing cancer treatment paradigms, and this review provides a timely update on the evolving landscape of cancer nanovaccines.

Agarose as a Tissue Mimic for the Porcine Heart, Kidney, and Liver: Measurements and a Springpot Model

Agarose gels are often used as a tissue mimic. The goal of this work was to determine the appropriate agarose concentrations that result in mechanical properties that match three different porcine organs. Strain tests were carried out with an amplitude varying from 0.01% to 10% at a frequency of 1 Hz on a range of agarose concentrations and porcine organs. Frequency sweep tests were performed from 0.1 Hz to a maximum of 9.5 Hz at a shear strain amplitude of 0.1% for agarose and porcine organs. In agarose samples, the effect of pre-compression of the samples up to 10% axial strain was considered during frequency sweep tests. The experimental measurements from agarose samples were fit to a fractional order viscoelastic (springpot) model. The model was then used to predict stress relaxation in response to a step strain of 0.1%. The prediction was compared to experimental relaxation data, and the results agreed within 12%. The agarose concentrations (by mass) that gave the best fit were 0.25% for the liver, 0.3% for the kidney, and 0.4% for the heart. At a frequency of 0.1 Hz and a shear strain of 0.1%, the agarose concentrations that best matched the shear storage modulus of the porcine organs were 0.4% agarose for the heart, 0.3% agarose for the kidney, and 0.25% agarose for the liver.

Biomimetic Materials for Skin Tissue Regeneration and Electronic Skin

Biomimetic materials have become a promising alternative in the field of tissue engineering and regenerative medicine to address critical challenges in wound healing and skin regeneration. Skin-mimetic materials have enormous potential to improve wound healing outcomes and enable innovative diagnostic and sensor applications. Human skin, with its complex structure and diverse functions, serves as an excellent model for designing biomaterials. Creating effective wound coverings requires mimicking the unique extracellular matrix composition, mechanical properties, and biochemical cues. Additionally, integrating electronic functionality into these materials presents exciting possibilities for real-time monitoring, diagnostics, and personalized healthcare. This review examines biomimetic skin materials and their role in regenerative wound healing, as well as their integration with electronic skin technologies. It discusses recent advances, challenges, and future directions in this rapidly evolving field.

Fabrication and Functional Regulation of Biomimetic Interfaces and Their Antifouling and Antibacterial Applications: A Review

Biomimetic synthesis provides potential guidance for the synthesis of bio-nanomaterials by mimicking the structure, properties and functions of natural materials. Behavioral studies of biological surfaces with specific micro/nano structures are performed to explore the interactions of various molecules or organisms with biological surfaces. These explorations provide valuable inspiration for the development of biomimetic surfaces with similar effects. This work reviews some conventional preparation methods and functional modulation strategies for biomimetic interfaces. It aims to elucidate the important role of biomimetic interfaces with antifouling and low-pollution properties that can replace non-environmentally friendly coatings. Thus, biomimetic antifouling interfaces can be better applied in the field of marine antifouling and antimicrobial. In this review, the commonly used fabrication methods for biomimetic interfaces as well as some practical strategies for functional modulation is present in detail. These methods and strategies modify the physical structure and chemical properties of the biomimetic interfaces, thus improving the wettability, adsorption, drag reduction, etc. that they exhibit. In addition, practical applications are presented of various biomimetic interfaces for antifouling and look ahead to potential biomedical applications. By continuously discovering functional surfaces with biomimetic properties and studying their microstructure and macroscopic properties, more biomimetic interfaces will be developed.

Antifouling applications and fabrications of biomimetic micro-structured surfaces: A review

BACKGROUND

Since the inception of the term "Biomimetics" in 1991, the concept of utilizing natural solutions or deriving inspiration from nature to address contemporary engineering challenges has gained significant attention within the scientific community. Organisms, in order to thrive in harsh environments, have evolved a wide range of micro/nanostructured surfaces, which serve as a rich source of inspiration for the development of artificial micro/nano-structured surfaces. These natural adaptations provide valuable insights and novel pathways for fabricating such surfaces.

AIM

To conclude recent advances in micro/nano-structured surfaces from four aspects: biomimetic micro-structured surfaces of plants and animals, properties and applications of biomimetic surfaces, methods of preparations, and their limitation.

KEY SCIENTIFIC CONCEPTS

Artificial micro/nano-structured surfaces inspired by animals and plants are classified and demonstrated according to their living environment. The performances, principles and preparation techniques of natural superhydrophobic surfaces, slippery liquid-infused porous surfaces (SLIPS), anisotropic surfaces, etc. are described in detail. Moreover, the pros and cons of each preparation measures are compared and the challenges developing large-scale, cost-effective surface microstructure preparation processes are pointed out. In the end, the development trends of artificial micro/nano-structured surface are forecasted.

Neutrophil-Mimetic, ROS Responsive, and Oxygen Generating Nanovesicles for Targeted Interventions of Refractory Rheumatoid Arthritis

Rheumatoid arthritis (RA) is the most prevalent inflammatory joint disease worldwide, leading to irreversible disability and even mortality. Unfortunately, current treatment regimens fail to cure RA due to low therapeutic responses and off-target side effects. Herein, a neutrophil membrane-cloaked, natural anti-arthritic agent leonurine (Leo), and catalase (CAT) co-loaded nanoliposomal system (Leo@CAT@NM-Lipo) is constructed to remodel the hostile microenvironment for RA remission. Due to the inflammation tropism inherited from neutrophils, Leo@CAT@NM-Lipo can target and accumulate in the inflamed joint cavity where high-level ROS can be catalyzed into oxygen by CAT to simultaneously accelerate the drug release and alleviate hypoxia at the lesion site. Besides, the neutrophil membrane camouflaging also enhances the anti-inflammatory potentials of Leo@CAT@NM-Lipo by robustly absorbing pro-arthritogenic cytokines and chemokines. Consequently, Leo@CAT@NM-Lipo successfully alleviated paw swelling, reduced arthritis score, mitigated bone and cartilage damage, and reversed multiple organ dysfunctions in adjuvant-induced arthritis rats (AIA) rats by synergistic effects of macrophage polarization, inflammation resolution, ROS scavenging, and hypoxia relief. Furthermore, Leo@CAT@NM-Lipo manifested excellent biocompatibility both at the cellular and animal levels. Taken together, the study provided a neutrophil-mimetic and ROS responsive nanoplatform for targeted RA therapy and represented a promising paradigm for the treatment of a variety of inflammation-dominated diseases.

Engineering mechanical compliance in polymers and composites for the design of smart flexible sensors

Polymers are one of the most popular materials for next-generation flexible sensing device fabrication due to their tunable mechanical and electrical properties. A series of prior research studies in the field of smart flexible and wearable sensing illustrates the potential of various polymer and composite materials to be applied in sensor development. In this direction, mechanical compliance plays a vital role as it ensures the stability and reliability of the fabricated sensor. Therefore, engineering mechanical compliance for the development of smart flexible solutions has emerged as a significant area of research. Furthermore, the usage of flexible sensing devices is rapidly increasing in the field of healthcare devices and robotic automation. This feature article summarizes the relevant contributions of the authors in the field of engineered polymers and composites for flexible sensor development with a focus on healthcare and physical sensing applications. We discuss the polymer and composite materials, their characteristics, fabrication technologies, finite element method analysis, and examples of flexible physical sensors, i.e. pressure, strain, and temperature sensors, for various wearable healthcare applications and robotic automation. Finally, we discuss examples of multi-sensory systems having flexible sensors.

Recent Advancements and Unexplored Biomedical Applications of Green Synthesized Ag and Au Nanoparticles: A Review

Green synthesis of silver (Ag) and gold (Au) nanoparticles (NPs) has acquired huge popularity owing to their potential applications in various fields. A large number of research articles exist in the literature describing the green synthesis of Ag and Au NPs for biomedical applications. However, these findings are scattered, making it time-consuming for researchers to locate promising advancements in Ag and Au NPs synthesis and their unexplored biomedical applications. Unlike other review articles, this systematic study not only highlights recent advancements in the green synthesis of Ag and Au NPs but also explores their potential unexplored biomedical applications. The article discusses the various synthesis approaches for the green synthesis of Ag and Au NPs highlighting the emerging developments and novel strategies. Then, the article reviews the important biomedical applications of green synthesized Ag and Au NPs by critically evaluating the expected advantages. To expose future research direction in the field, the article describes the unexplored biomedical applications of the NPs. Finally, the articles discuss the challenges and limitations in the green synthesis of Ag and Au NPs and their biomedical applications. This article will serve as a valuable reference for researchers, working on green synthesis of Ag and Au NPs for biomedical applications.

ON/OFF based synergetic plasmonic photothermal drug release approach through core-satellite like mussel-inspired polydopamine nanoparticles

One of the studies on new drug delivery and release systems that has increased in recent years is the study using plasmonic nanoparticles. In this study, polydopamine nanoparticles (PDOP NPs), which contribute to photothermal drug release by near infrared radiation (NIR), were decorated with gold nanoparticles (AuNPs) to utilize their plasmonic properties, and a core-satellite-like system was formed. With this approach, epirubicin (EPI)-loaded PDOP NPs were prepared by utilizing the plasmonic properties of AuNPs. Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) methods were used to evaluate the structural properties of these particles. The release behavior of the prepared structures in acidic (pH 5.0) and neutral (pH 7.4) environments based on the ON/OFF approach was also examined. The biocompatibility properties of the particles were evaluated on mouse fibroblast (L929) and anticancer activities on neuroblastoma (SH-SY5Y) cells. The effects of prepared EPI-loaded particles and laser-controlled drug release on ROS production, genotoxicity, and apoptosis were also investigated in SH-SY5Y cells. With the calculated combination index (CI) value, it was shown that the activity of EPI-loaded AuNP@PDOP NPs increased synergistically with the ON/OFF-based approach. The developed combination approach is considered to be remarkable and promising for further evaluation before clinical use.

Strategies in surface engineering for the regulation of microclimates in skin-medical product interactions

There is a growing number of personal healthcare devices that are in prolonged contact with the skin. The functionality of these products is linked to the interface formed by the contact between the medical apparatus and the skin. The interface can be characterised by its topology, compliance, and moisture and thermal regulating capabilities. Many devices are, however, described to have suboptimal and occlusive contacts, resulting in physiological unfavourable microclimates at the interface. The resulting poor management of moisture and temperature can impact the functionality and utility of the device and, in severe cases, lead to physical harm to the user. Being able to control the microclimate is therefore expected to limit medical-device related injuries and prevent associated skin complications. Surface engineering can modify and potentially enhance the regulation of the microclimate factors surrounding the interface between a product's surface and the skin. This review provides an overview of potential engineering solutions considering the needs for, and influences on, regulation of temperature and moisture by considering the skin-medical device interface as a system. These findings serve as a platform for the anticipated progress in the role of surface engineering for skin-device microclimate regulation.

Design of manganese-based nanomaterials for pharmaceutical and biomedical applications

In the past few years, manganese-based nanostructures have been extensively investigated in the biomedical field particularly to design highly biocompatible theranostics, which can not only act as efficient diagnostic imaging contrast agents but also deliver the drugs to the target sites. The nanoscale size, large surface area-to-volume ratio, availability of cheap precursors, flexibility to synthesize nanostructures with reproducible properties and high yield, and easy scale up are the major reasons for the attraction towards manganese nanostructures. Along with these properties, the nontoxic nature, pH-sensitive degradation, and easy surface functionalization are additional benefits for the use of manganese nanostructures in biomedical and pharmaceutical sciences. Therefore, in this review, we discuss the recent progress made in the synthesis of manganese nanostructures, describe the attempts made to modify their surfaces to impart biocompatibility and stability in biological fluids, and critically discuss their use in magnetic resonance imaging, drug and gene delivery, hyperthermia, photothermal/photodynamic, immunotherapy, biosensing and tumor diagnosis.

Bioinspired Multifunctional Silver Nanoparticles for Optical Sensing Applications: A Sustainable Approach

Silver nanoparticles developed via biosynthesis are the most fascinating nanosized particles and encompassed with excellent physicochemical properties. The bioinspired nanoparticles with different shapes and sizes have attracted huge attention due to their stability, low cost, environmental friendliness, and use of less hazardous chemicals. This is an ideal method for synthesizing a range of nanosized metal particles from plants and biomolecules. Optical biosensors are progressively being fabricated for the attainment of sustainability by using opportunities offered by nanotechnology. This review focuses mainly on tuning the optical properties of the metal nanoparticles for optical sensing to explore the importance and applications of bioinspired silver nanoparticles. Further, this review deliberates the role of bioinspired silver nanoparticles (Ag NPs) in biomedical, agricultural, environmental, and energy applications. Profound insight into the antimicrobial properties of these nanoparticles is also appreciated. Tailor-made bioinspired nanoparticles with effectuating characteristics can unsurprisingly target tumor cells and distribute enwrapped payloads intensively. Existing challenges and prospects of bioinspired Ag NPs are also summarized. This review is expected to deliver perceptions about the progress of the next generation of bioinspired Ag NPs and their outstanding performances in various fields by promoting sustainable practices for fabricating optical sensing devices.

Current research trends of nanomedicines

Owing to the inherent shortcomings of traditional therapeutic drugs in terms of inadequate therapeutic efficacy and toxicity in clinical treatment, nanomedicine designs have received widespread attention with significantly improved efficacy and reduced non-target side effects. Nanomedicines hold tremendous theranostic potential for treating, monitoring, diagnosing, and controlling various diseases and are attracting an unfathomable amount of input of research resources. Against the backdrop of an exponentially growing number of publications, it is imperative to help the audience get a panorama image of the research activities in the field of nanomedicines. Herein, this review elaborates on the development trends of nanomedicines, emerging nanocarriers, in vivo fate and safety of nanomedicines, and their extensive applications. Moreover, the potential challenges and the obstacles hindering the clinical translation of nanomedicines are also discussed. The elaboration on various aspects of the research trends of nanomedicines may help enlighten the readers and set the route for future endeavors.

Bacteria and Bacterial Components as Natural Bio-Nanocarriers for Drug and Gene Delivery Systems in Cancer Therapy

Bacteria and bacterial components possess multifunctional properties, making them attractive natural bio-nanocarriers for cancer diagnosis and targeted treatment. The inherent tropic and motile nature of bacteria allows them to grow and colonize in hypoxic tumor microenvironments more readily than conventional therapeutic agents and other nanomedicines. However, concerns over biosafety, limited antitumor efficiency, and unclear tumor-targeting mechanisms have restricted the clinical translation and application of natural bio-nanocarriers based on bacteria and bacterial components. Fortunately, bacterial therapies combined with engineering strategies and nanotechnology may be able to reverse a number of challenges for bacterial/bacterial component-based cancer biotherapies. Meanwhile, the combined strategies tend to enhance the versatility of bionanoplasmic nanoplatforms to improve biosafety and inhibit tumorigenesis and metastasis. This review summarizes the advantages and challenges of bacteria and bacterial components in cancer therapy, outlines combinatorial strategies for nanocarriers and bacterial/bacterial components, and discusses their clinical applications.

Alginate Microsponges as a Scaffold for Delivery of a Therapeutic Peptide against Rheumatoid Arthritis

The quest for biocompatible drug-delivery devices that could be able to open new administration routes is at the frontier of biomedical research. In this contribution, porous polysaccharide-based microsponges based on crosslinked alginate polymers were developed and characterized by optical spectroscopy and nanoscopic microscopy techniques. We show that macropores with a size distribution ranging from 50 to 120 nm enabled efficient loading and delivery of a therapeutic peptide (CIGB814), presently under a phase 3 clinical trial for the treatment of rheumatoid arthritis. Alginate microsponges showed 80% loading capacity and sustained peptide release over a few hours through a diffusional mechanism favored by partial erosion of the polymer scaffold. The edible and biocompatible nature of alginate polymers open promising perspectives for developing a new generation of polysaccharide-based carriers for the controlled delivery of peptide drugs, exploiting alternative routes with respect to intravenous administration.

The applications of functional materials-based nano-formulations in the prevention, diagnosis and treatment of chronic inflammation-related diseases

Chronic inflammation, in general, refers to systemic immune abnormalities most often caused by the environment or lifestyle, which is the basis for various skin diseases, autoimmune diseases, cardiovascular diseases, liver diseases, digestive diseases, cancer, and so on. Therapeutic strategies have focused on immunosuppression and anti-inflammation, but conventional approaches have been poor in enhancing the substantive therapeutic effect of drugs. Nanomaterials continue to attract attention for their high flexibility, durability and simplicity of preparation, as well as high profitability. Nanotechnology is used in various areas of clinical medicine, such as medical diagnosis, monitoring and treatment. However, some related problems cannot be ignored, including various cytotoxic and worsening inflammation caused by the nanomaterials themselves. This paper provides an overview of functional nanomaterial formulations for the prevention, diagnosis and treatment of chronic inflammation-related diseases, with the intention of providing some reference for the enhancement and optimization of existing therapeutic approaches.

Bacillussp. based nano-bio hybrids for efficient water remediation

Macroalgae are a diverse group of primary producers that offer indispensable ecosystem services towards bacterial colonization and proliferation in aquatic biomes. Macroalgae/bacteria interactions are complex in natural biomes and contribute mutually to their growth and biotechnological outcomes. Most findings on macroalgae-associated bacteria and their secreted enzymes have largely been limited to nutraceutical applications. Here, in this study, we demonstrate and investigate the growth of Bacillus sp. (macroalgae-associated bacteria) with the substitution of its associated macroalgae (Gracilaria corticata) on graphene oxide (GO). The findings indicated that the presence of wrinkles of GO nanosheets resulted in cell proliferation and adherence without causing mechanical damage to the cell membrane. Furthermore, the assembly of GO-marine bacteria was explored for organic pollutant treatment using methylene blue (MB) as a model dye. The degradation results suggest the breakdown of MB into non-toxic byproducts as suggested by the phytotoxicity assay.

Bioinspired Lipid Nanocarriers for RNA Delivery

RNA therapy is a disruptive technology comprising a rapidly expanding category of drugs. Further translation of RNA therapies to the clinic will improve the treatment of many diseases and help enable personalized medicine. However, in vivo delivery of RNA remains challenging due to the lack of appropriate delivery tools. Current state-of-the-art carriers such as ionizable lipid nanoparticles still face significant challenges, including frequent localization to clearance-associated organs and limited (1-2%) endosomal escape. Thus, delivery vehicles must be improved to further unlock the full potential of RNA therapeutics. An emerging strategy is to modify existing or new lipid nanocarriers by incorporating bioinspired design principles. This method generally aims to improve tissue targeting, cellular uptake, and endosomal escape, addressing some of the critical issues facing the field. In this review, we introduce the different strategies for creating bioinspired lipid-based RNA carriers and discuss the potential implications of each strategy based on reported findings. These strategies include incorporating naturally derived lipids into existing nanocarriers and mimicking bioderived molecules, viruses, and exosomes. We evaluate each strategy based on the critical factors required for delivery vehicles to succeed. Finally, we point to areas of research that should be furthered to enable the more successful rational design of lipid nanocarriers for RNA delivery.

Nano zinc oxide-functionalized nanofibrous microspheres: A bioactive hybrid platform with antimicrobial, regenerative and hemostatic activities

Bioactive hybrid constructs are at the cutting edge of innovative biomaterials. PLA nanofibrous microspheres (NF-MS) were functionalized with zinc oxide nanoparticles (nZnO) and DDAB-modified nZnO (D-nZnO) for developing inorganic/nano-microparticulate hybrid constructs (nZnO@NF-MS and D-nZnO@NF-MS) merging antibacterial, regenerative, and haemostatic functionalities. The hybrids appeared as three-dimensional NF-MS frameworks made-up entirely of interconnecting nanofibers embedding nZnO or D-nZnO. Both systems achieved faster release of Zn²⁺ than their respective nanoparticles and D-nZnO@NF-MS exhibited significantly greater surface wettability than nZnO@NF-MS. Regarding bioactivity, D-nZnO@NF-MS displayed a significantly greater and fast-killing effect against Staphylococcus aureus. Both nZnO@NF-MS and D-nZnO@NF-MS showed controllable concentration-dependent cytotoxicity to human gingival fibroblasts (HGF) compared with pristine NF-MS. They were also more effective than pristine NF-MS in promoting migration of human gingival fibroblasts (HGF) in the in vitro wound healing assay. Although D-nZnO@NF-MS showed greater in vitro hemostatic activity than nZnO@NF-MS, (blood-clotting index 22.82 ± 0.65% vs.54.67 ±2.32%) both structures exhibited instant hemostasis (0 s) with no blood loss (0 mg) in the rat-tail cutting technique. By merging the multiple therapeutic bioactivities of D-nZnO and the 3D-structural properties of NF-MS, the innovative D-nZnO@NF-MS hybrid construct provides a versatile bioactive material platform for different biomedical applications.

Craniofacial therapy: advanced local therapies from nano-engineered titanium implants to treat craniofacial conditions

Nano-engineering-based tissue regeneration and local therapeutic delivery strategies show significant potential to reduce the health and economic burden associated with craniofacial defects, including traumas and tumours. Critical to the success of such nano-engineered non-resorbable craniofacial implants include load-bearing functioning and survival in complex local trauma conditions. Further, race to invade between multiple cells and pathogens is an important criterion that dictates the fate of the implant. In this pioneering review, we compare the therapeutic efficacy of nano-engineered titanium-based craniofacial implants towards maximised local therapy addressing bone formation/resorption, soft-tissue integration, bacterial infection and cancers/tumours. We present the various strategies to engineer titanium-based craniofacial implants in the macro-, micro- and nano-scales, using topographical, chemical, electrochemical, biological and therapeutic modifications. A particular focus is electrochemically anodised titanium implants with controlled nanotopographies that enable tailored and enhanced bioactivity and local therapeutic release. Next, we review the clinical translation challenges associated with such implants. This review will inform the readers of the latest developments and challenges related to therapeutic nano-engineered craniofacial implants.

Electrospun fibers with blank surface and inner drug gradient for improving sustained release

New engineering methods and advanced strategies are highly desired for creating novel drug sustained release nanomaterials. In this study, a trilayer concentric spinneret was explored to implement several multifluid electrospinning processes. A trilayer core-shell nanofiber was successfully fabricated, which comprise a drug-free polymeric coating and an inner drug gradient distribution, and then compared with bilayer core-shell and monolithic medicated nanofibers. All the electrospun nanofibers similarly consisted of two components (guest drug acetaminophen and host polymer cellulose acetate) and presented a linear morphology. Due to the secondary interactions within nanofibers, loaded drug with amorphous state was detected, as demonstrated by SEM, DSC, XRD, and FTIR determinations. In vitro and in vivo gavage treatments to rats tests were carried out, the trilayer nanofiber with an elaborate structure design were demonstrated to provide better drug sustained release profile than the bilayer core-shell nanofibers in term of initial burst release, later tail-off release and long sustained release time period. The synergistic mechanism for improving the drug sustained release behaviors is disclosed. By breaking the traditional concepts about the implementation of multifluid electrospinning and the strategy of combining surface properties and inner structural characteristics, the present protocols open a new way for developing material processing methods and generating novel functional nanomaterials.

Research Progress of Bioinspired Nanostructured Systems for the Treatment of Ocular Disorders

How to enhance the bioavailability and prolong the residence time of drugs in the eye present the major barriers to traditional eye delivery. Nanotechnology has been widely used in ocular drug delivery systems because of its advantages of minimizing adverse reactions, decreasing the frequency of administration, prolonging the release time, and improving the bioavailability of the drug in the eye. As natural product-based nanostructured systems, bioinspired nanostructured systems have presented as less toxic, easy to prepare, and cost-effective and have potential application value in the field of nanotechnology. A systematic classification of bioinspired nanostructured systems based on their inspiration source and formulation and their brief applications in disease are presented here. A review of recent research progress of the bioinspired nanostructured systems for the treatment of the anterior and posterior segment of ocular disorders is then presented in detail. Finally, current challenges and future directions with regard to manufacturing bioinspired nanomaterials are provided.

Immunogenic Cell Death Activates the Tumor Immune Microenvironment to Boost the Immunotherapy Efficiency

Tumor immunotherapy is only effective in a fraction of patients due to a low response rate and severe side effects, and these challenges of immunotherapy in clinics can be addressed through induction of immunogenic cell death (ICD). ICD is elicited from many antitumor therapies to release danger associated molecular patterns (DAMPs) and tumor-associated antigens to facilitate maturation of dendritic cells (DCs) and infiltration of cytotoxic T lymphocytes (CTLs). The process can reverse the tumor immunosuppressive microenvironment to improve the sensitivity of immunotherapy. Nanostructure-based drug delivery systems (NDDSs) are explored to induce ICD by incorporating therapeutic molecules for chemotherapy, photosensitizers (PSs) for photodynamic therapy (PDT), photothermal conversion agents for photothermal therapy (PTT), and radiosensitizers for radiotherapy (RT). These NDDSs can release loaded agents at a right dose in the right place at the right time, resulting in greater effectiveness and lower toxicity. Immunotherapeutic agents can also be combined with these NDDSs to achieve the synergic antitumor effect in a multi-modality therapeutic approach. In this review, NDDSs are harnessed to load multiple agents to induce ICD by chemotherapy, PDT, PTT, and RT in combination of immunotherapy to promote the therapeutic effect and reduce side effects associated with cancer treatment.

A review on contemporary nanomaterial-based therapeutics for the treatment of diabetic foot ulcers (DFUs) with special reference to the Indian scenario

Diabetes mellitus (DM) is a predominant chronic metabolic syndrome, resulting in various complications and high mortality associated with diabetic foot ulcers (DFUs). Approximately 15-30% of diabetic patients suffer from DFUs, which is expected to increase annually. The major challenges in treating DFUs are associated with wound infections, alterations to inflammatory responses, angiogenesis and lack of extracellular matrix (ECM) components. Furthermore, the lack of targeted therapy and efficient wound dressings for diabetic wounds often results in extended hospitalization and limb amputations. Hence, it is essential to develop and improve DFU-specific therapies. Nanomaterial-based innovative approaches have tremendous potential for preventing and treating wound infections of bacterial origin. They have greater benefits compared to traditional wound dressing approaches. In this approach, the physiochemical features of nanomaterials allow researchers to employ different methods for diabetic wound healing applications. In this review, the status and prevalence of diabetes mellitus (DM) and amputations due to DFUs in India, the pathophysiology of DFUs and their complications are discussed. Additionally, nanomaterial-based approaches such as the use of nanoemulsions, nanoparticles, nanoliposomes and nanofibers for the treatment of DFUs are studied. Besides, emerging therapeutics such as bioengineered skin substitutes and nanomaterial-based innovative approaches such as antibacterial hyperthermia therapy and gene therapy for the treatment of DFUs are highlighted. The present nanomaterial-based techniques provide a strong base for future therapeutic approaches for skin regeneration strategies in the treatment of diabetic wounds.