Engineered nanoflowers, nanotrees, nanostars, nanodendrites, and nanoleaves for biomedical applications
Authors/Creators
Description
Highlights of the Study
This review provides a comprehensive overview of engineered nanostructures with complex bioinspired geometries, including nanoflowers, nanotrees, nanostars, nanodendrites, and nanoleaves. Particular attention is given to how morphology, size, surface architecture, composition, and fabrication methods determine their physicochemical and biological properties. Their major biomedical applications—including drug and gene delivery, biosensing, bioimaging, cancer therapy, photothermal treatment, antibacterial applications, and molecular diagnostics—are critically discussed together with current limitations and future opportunities.
Key findings:
🟢 Morphology-dependent performance: Nanoparticle shape is a critical design parameter that can influence cellular uptake, uptake kinetics, intracellular distribution, cytotoxicity, optical properties, and interactions with biological systems. Aspect ratio and surface geometry can also substantially alter cellular internalization.
🟢 High surface-area architectures: The branched and hierarchical geometries of these nanostructures provide large surface-to-volume ratios and abundant active sites, improving mass transfer, surface reactions, biomolecule loading, catalytic activity, and interactions with biological targets.
🟢 Nanoflowers: Nanoflowers are flower-like nanostructures with high surface-to-volume ratios and can be fabricated from metals, metal oxides, sulfides, polymers, proteins, enzymes, DNA, and organic–inorganic hybrids. Their biomedical applications include drug and gene delivery, biosensing, cancer therapy, antibacterial treatment, wound healing, and bioimaging.
🟢 Gold nanoflowers: The irregular tips, corners, junctions, and edges of gold nanoflowers generate distinctive plasmonic and near-infrared properties, supporting applications in SERS, photothermal cancer therapy, imaging, and therapeutic delivery.
🟢 ZnO nanoflowers: ZnO nanoflowers have demonstrated antibacterial, proangiogenic, wound-healing, biosensing, and neurogenic potential. Their antimicrobial behavior can involve Zn²⁺ release, reactive oxygen species generation, membrane damage, DNA disruption, and interference with cellular energy metabolism.
🟢 MoS₂ nanoflowers: Layered MoS₂ nanoflowers exhibit strong photothermal characteristics and have been investigated as platforms for cancer thermal therapy and ROS-mediated antitumor treatment.
🟢 DNA and hybrid nanoflowers: DNA-based and organic–inorganic hybrid nanoflowers offer controllable morphology, functionalization, biocompatibility, and cargo-loading capabilities, making them promising platforms for targeted drug delivery, sensing, biocatalysis, and therapeutic applications.
🟢 Nanotrees: Nanotrees can be produced through one-step growth, sequential branched growth, and template-assisted approaches. Their branched three-dimensional architectures provide high surface area, rapid electron transfer, favorable crystallinity, and efficient charge-transfer characteristics.
🟢 Nanotree fabrication: Hydrothermal, solvothermal, vapor-phase, chemical vapor deposition, laser-ablation, and related techniques have been employed to construct nanotree structures. However, compared with other architectures, their biomedical potential remains relatively understudied.
🟢 Nanostars: Gold nanostars combine a central core with multiple sharp tips, generating strong geometry-dependent plasmonic behavior and high absorption in the near-infrared region. These properties make them particularly attractive for SERS, CT and photoacoustic imaging, photothermal therapy, drug delivery, and cancer treatment.
🟢 Shape-dependent cellular uptake: The biological behavior of gold nanostars is highly dependent on particle size, geometry, cell type, surface chemistry, and experimental environment. Different cell types can therefore exhibit substantially different internalization profiles for the same nanoparticle morphology.
🟢 Stimuli-responsive drug delivery: Gold nanostars have been integrated with mesoporous silica, thermosensitive materials, liposomes, ZIF-based metal–organic frameworks, peptides, and cell-membrane coatings to enable controlled or stimuli-responsive delivery of anticancer agents.
🟢 Combined cancer therapy: Nanostar-based systems can integrate drug delivery with photothermal conversion, allowing chemo-photothermal strategies in which NIR irradiation simultaneously triggers therapeutic release and localized heating of tumor tissue.
🟢 Antibacterial nanostars: The photothermal properties and sharp surface features of gold nanostars can also contribute to antibacterial activity through localized heating and physical disruption of bacterial cell walls or membranes.
🟢 Nanodendrites: Nanodendritic structures provide high surface areas and tunable shape-dependent optical, electronic, and physicochemical properties. Their branched architecture enhances loading of bioactive molecules and permits functionalization with targeting molecules such as antibodies and proteins.
🟢 Nanodendrite applications: Metallic and hybrid nanodendrites have been investigated for drug delivery, molecular imaging, photodynamic therapy, photoacoustic imaging, biosensing, diagnostics, antibacterial treatment, and wound healing.
🟢 Nanoleaves: Leaf-shaped nanostructures contain microporous architectures that can facilitate reactant transport toward active surface sites and improve carrier transport during sensing. These characteristics support their application in electrochemical and biosensing systems.
🟢 CuO nanoleaf biosensors: Hierarchical CuO nanoleaves have demonstrated promising performance as nonenzymatic glucose sensors, including a reported detection limit of 12 nM together with high sensitivity, selectivity, reproducibility, and stability.
🟢 Broad biomedical applications: Collectively, these architectured nanomaterials have been investigated for drug delivery, gene delivery, biosensing, bioimaging, cancer treatment, antibacterial therapy, molecular diagnostics, photothermal therapy, and other advanced biomedical applications.
🟢 Key advantages: Their major advantages include large surface areas, geometry-dependent optical and electronic properties, enhanced loading capacity, tunable functionalization, high catalytic activity, improved mass transfer, and the possibility of combining diagnostic and therapeutic functions within a single nanoplatform.
🟢 Safety and fabrication challenges: Biological performance cannot be predicted from composition alone. Particle size, morphology, sharpness, surface chemistry, fabrication route, and cell type can substantially influence toxicity and biocompatibility. Chemical fabrication processes may also generate toxic residues or byproducts.
🟢 Nanoflower limitations: Although nanoflowers offer high surface area and can be produced through environmentally friendly approaches, precise structural control during synthesis remains challenging, and some fabrication methods may generate toxic products or reduce protein and peptide activity.
🟢 Future research opportunities: Further investigation is needed to establish reproducible morphology–property–biological response relationships, improve structural control and scalable fabrication, optimize biocompatibility, and translate these complex architectures into clinically relevant nanomedicine platforms.
Overall, this review demonstrates that nanoflowers, nanotrees, nanostars, nanodendrites, and nanoleaves represent a versatile family of architectured nanomaterials whose biomedical performance is strongly governed by geometry. Their high surface areas, branched structures, tunable optical and electronic properties, and functionalization capabilities enable applications ranging from drug delivery and biosensing to bioimaging, antibacterial treatment, and multimodal cancer therapy. At the same time, morphology-dependent toxicity, fabrication control, reproducibility, and biological safety remain important challenges that must be addressed for successful clinical translation.
KEYWORDS
Nanoparticles • Nanoflowers • Nanotrees • Nanostars • Nanodendrites • Nanoleaves
HOW TO CITE
Khakbiz, M., Shakibania, S., Ghazanfari, L., Zhao, S., Tavakoli, M., & Chen, Z. (2023). Engineered nanoflowers, nanotrees, nanostars, nanodendrites, and nanoleaves for biomedical applications. Nanotechnology Reviews, 12, 20220523.
DOI: 10.1515/ntrev-2022-0523
Journal: Nanotechnology Reviews
Article Link: https://doi.org/10.1515/ntrev-2022-0523
Abstract
The development of architectured nanomaterials has been booming in recent years in part due to their expanded applications in the biomedical field, such as biosensing, bioimaging, drug delivery, and cancer therapeutics. Nanomaterials exhibit a wide variety of shapes depending on both the intrinsic properties of the materials and the synthesis procedures. Typically, the large surface areas of nanomaterials improve the rate of mass transfer in biological reactions. They also have high self-ordering and assembly behaviors, which make them great candidates for various biomedical applications. Some nanomaterials have a high conversion rate in transforming the energy of photons into heat or fluorescence, thus showing promise in cancer treatment (such as hyperthermia) and bioimaging. The nanometric dimension makes them suitable for passing through the biological barriers or interacting with the natural molecules (such as DNA, protein). Nanoflowers, nanotrees, nanostars, and nanodendrites are examples of nano-sized structures, which exhibit unique geometry-dependent properties. Here we reviewed the fabrication methods, features, properties, and biomedical applications of four nano-structured materials including nanoflowers, nanotrees, nanostars, nanodendrites, and nanoleaves. We further provided our perspectives on employing these novel nanostructures as advanced functional materials for a broad spectrum of applications.