Fluorescent Nanorods and Nanospheres for Real-Time In Vivo Probing of Nanoparticle Shape-Dependent Tumor Penetration

Nanoparticle transport in biomimetic polymer-linked emulsions

The ability of nanoparticles to penetrate and transport through soft tissues is essential to delivering therapeutics to treat diseases or signaling agents for advanced imaging and sensing. Nanoparticle transport in biological systems, however, is challenging to predict and control due to the physicochemical complexity of tissues and biological fluids. Here, we demonstrate that nanoparticles suspended in a novel class of soft matter-polymer-linked emulsions (PLEs)-exhibit characteristics essential for mimicking transport in biological systems, including subdiffusive dynamics, non-Gaussian displacement distributions, and decoupling of dynamics from material viscoelasticity. Using multiple particle tracking, we identify the physical mechanisms underlying this behavior, which we attribute to a coupling of nanoparticle dynamics to fluctuations in the local network of polymer-linked droplets. Our findings demonstrate the potential of PLEs to serve as fully synthetic mimics of biological transport.

New role of bacteriophages in medical oncology

Targeted treatment of cancer is one of the most paramount approaches in cancer treatment. Despite significant advances in cancer diagnosis and treatment methods, there are still significant limitations and disadvantages in the field, including high costs, toxicity, and unwanted damage to healthy cells. The phage display technique is an innovative method for designing carriers containing exogenic peptides with cancer diagnostic and therapeutic properties. Bacteriophages possess unique properties making them effective in cancer treatment. These characteristics include the small size enabling them to penetrate vessels; having no pathogenicity to mammals; easy manipulation of their genetic information and surface proteins to introduce vaccines and drugs to cancer tissues; lower cost of large-scale production; and greater stimulation of the immune system. Bacteriophages will certainly play a more effective role in the future of medical oncology; however, studies are in the early stages of conception and require more extensive research. We aimed in this review to provide some related examples and bring insights into the potential of phages as targeted vectors for use in cancer diagnosis and treatment, especially regarding their capability in gene and drug delivery to cancer target cells, determination of tumor markers, and vaccine design to stimulate anticancer immunity.

Dipeptide nanostructures: Synthesis, interactions, advantages and biomedical applications

Short peptides are important in the design of self-assembled materials due to their versatility and flexibility. Self-assembled dipeptides, a group of peptide nanostructures, have highly attractive uses in the field of biomedicine. Recently these materials have proved to be important nanostructures because of their biocompatibility, low-cost and simplicity of synthesis, functionality/easy tunability and nano dimensions. Although there are different studies on peptide and protein-based nanostructures, more information about self-assembled nanostructures for dipeptides is still required to discover the advantages, challenges, importance, synthesis, interactions, and applications. This review describes and discusses the self-assembled dipeptide nanostructures especially for biomedical applications.

Multifunctional Plant Virus Nanoparticles for Targeting Breast Cancer Tumors

Breast cancer treatment using plant-virus-based nanoparticles (PVNPs) has achieved considerable success in preclinical studies. PVNP-based breast cancer therapies include non-targeted and targeted nanoplatforms for delivery of anticancer therapeutic chemo and immune agents and cancer vaccines for activation of local and systemic antitumor immunity. Interestingly, PVNP platforms combined with other tumor immunotherapeutic options and other modalities of oncotherapy can improve tumor efficacy treatment. These applications can be achieved by encapsulation of a wide range of active ingredients and conjugating ligands for targeting immune and tumor cells. This review presents the current breast cancer treatments based on PVNP platforms.

Hyaluronic acid-based nano drug delivery systems for breast cancer treatment: Recent advances

Breast cancer (BC) is the most common malignancy among females worldwide, and high resistance to drugs and metastasis rates are the leading causes of death in BC patients. Releasing anti-cancer drugs precisely to the tumor site can improve the efficacy and reduce the side effects on the body. Natural polymers are attracting extensive interest as drug carriers in treating breast cancer. Hyaluronic acid (HA) is a natural polysaccharide with excellent biocompatibility, biodegradability, and non-immunogenicity and is a significant component of the extracellular matrix. The CD44 receptor of HA is overexpressed in breast cancer cells and can be targeted to breast tumors. Therefore, many researchers have developed nano drug delivery systems (NDDS) based on the CD44 receptor tumor-targeting properties of HA. This review examines the application of HA in NDDSs for breast cancer in recent years. Based on the structural composition of NDDSs, they are divided into HA NDDSs, Modified HA NDDSs, and HA hybrid NDDSs.

Nanomedicine Penetration to Tumor: Challenges, and Advanced Strategies to Tackle This Issue

Nanomedicine has been under investigation for several years to improve the efficiency of chemotherapeutics, having minimal pharmacological effects clinically. Ineffective tumor penetration is mediated by tumor environments, including limited vascular system, rising cancer cells, higher interstitial pressure, and extra-cellular matrix, among other things. Thus far, numerous methods to increase nanomedicine access to tumors have been described, including the manipulation of tumor micro-environments and the improvement of nanomedicine characteristics; however, such outdated approaches still have shortcomings. Multi-functional convertible nanocarriers have recently been developed as an innovative nanomedicine generation with excellent tumor infiltration abilities, such as tumor-penetrating peptide-mediated transcellular transport. The developments and limitations of nanomedicines, as well as expectations for better outcomes of tumor penetration, are discussed in this review.

Bioimaging guided pharmaceutical evaluations of nanomedicines for clinical translations

Nanomedicines (NMs) have emerged as an efficient approach for developing novel treatment strategies against a variety of diseases. Over the past few decades, NM formulations have received great attention, and a large number of studies have been performed in this field. Despite this, only about 60 nano-formulations have received industrial acceptance and are currently available for clinical use. Their in vivo pharmaceutical behavior is considered one of the main challenges and hurdles for the effective clinical translation of NMs, because it is difficult to monitor the pharmaceutic fate of NMs in the biological environment using conventional pharmaceutical evaluations. In this context, non-invasive imaging modalities offer attractive solutions, providing the direct monitoring and quantification of the pharmacokinetic and pharmacodynamic behavior of labeled NMs in a real-time manner. Imaging evaluations have great potential for revealing the relationship between the physicochemical properties of NMs and their pharmaceutical profiles in living subjects. In this review, we introduced imaging techniques that can be used for in vivo NM evaluations. We also provided an overview of various studies on the influence of key parameters on the in vivo pharmaceutical behavior of NMs that had been visualized in a non-invasive and real-time manner.

Towards principled design of cancer nanomedicine to accelerate clinical translation

Nanotechnology in medical applications, especially in oncology as drug delivery systems, has recently shown promising results. However, although these advances have been promising in the pre-clinical stages, the clinical translation of this technology is challenging. To create drug delivery systems with increased treatment efficacy for clinical translation, the physicochemical characteristics of nanoparticles such as size, shape, elasticity (flexibility/rigidity), surface chemistry, and surface charge can be specified to optimize efficiency for a given application. Consequently, interdisciplinary researchers have focused on producing biocompatible materials, production technologies, or new formulations for efficient loading, and high stability. The effects of design parameters can be studied in vitro, in vivo, or using computational models, with the goal of understanding how they affect nanoparticle biophysics and their interactions with cells. The present review summarizes the advances and technologies in the production and design of cancer nanomedicines to achieve clinical translation and commercialization. We also highlight existing challenges and opportunities in the field.

Effect of micro- and nanoparticle shape on biological processes

In the drug delivery field, there is beyond doubt that the shape of micro- and nanoparticles (M&NPs) critically affects their biological fate. Herein, following an introduction describing recent technological advances for designing nonspherical M&NPs, we highlight the role of particle shape in cell capture, subcellular distribution, intracellular drug delivery, and cytotoxicity. Then, we discuss theoretical approaches for understanding the effect of particle shape on internalization by the cell membrane. Subsequently, recent advances on shape-dependent behaviors of M&NPs in the systemic circulation are detailed. In particular, the interaction of M&NPs with blood proteins, biodistribution, and circulation under flow conditions are analyzed. Finally, the hurdles and future directions for developing nonspherical M&NPs are underscored.

Spontaneous formation of anisotropic microrods from paraffin wax in an aqueous environment

The construction of functional nano-/micro-architectures through self-assembly and self-organization of organic molecules and polymeric materials plays an important role in the development of many technologies. In this study, we report the spontaneous formation of uniform polymer microrods with lengths of up to a few tens of micrometers from paraffin wax. Through a solvent attrition approach, colloidal structures of paraffin wax are introduced into water. After the initial growth stage, the microrods undergo morphological transformation and end-to-end aggregation, processes likely driven by thermodynamics to create equilibrium structures with minimal interfacial energies. The polymer microrods can effectively absorb hydrophobic nanoparticles, indicating their potential to serve as host materials for functional components. The formation of polymer microrods from paraffin wax and their spontaneous growth mechanism discovered in this study may provide new insights to the self-assembly of microstructures.

Simple preparation of photothermal nanomaterial GNR@SiO2 with enhanced drug loading content

With the rising threat of cancers, gold nanorods (GNRs) based photothermal-chemotherapy is becoming an increasingly important strategy to cure cancers. There are some challenges faced by GNRs system including complicated synthesis process and low drug loading capacity. In this study, GNRs assisted mesoporous silica nanoparticles (GNR@SiO₂ NPs) are fabricated by a simple method. The mesoporous SiO₂ can not only prevent the aggregation of GNRs but also provide large hollow mesoporous structure to enhance drug loading capacity. Moreover, GNRs absorb near-infrared (NIR) light and convert it into heat. The temperature of the GNR@SiO₂ solution was increased to ∼60 (2 W) and 90°C (3 W) after NIR radiation. The photothermal conversion efficiency was 32.60% of GNR@SiO₂ under NIR light irradiation at 2 W, while 39.01% under NIR light irradiation at 3 W. The drug loading content of GNR@SiO₂ was 22.3 ± 2.5%, which was higher than that of most reported GNR drug delivery systems. The authors also found that the GNR@SiO₂@ doxorubicin may have a higher drug release rate under the conditions of the tumour microenvironment. The in vitro cytotoxity of GNR@SiO₂ was demonstrated on HeLa cells. The experimental results indicate that GNR@SiO₂ has great potential for synergistic treatment to kill cancer cells.

Drug delivery vectors based on filamentous bacteriophages and phage-mimetic nanoparticles

With the development of nanomedicine, a mass of nanocarriers have been exploited and utilized for targeted drug delivery, including liposomes, polymers, nanoparticles, viruses, and stem cells. Due to huge surface bearing capacity and flexible genetic engineering property, filamentous bacteriophage and phage-mimetic nanoparticles are attracting more and more attentions. As a rod-like bio-nanofiber without tropism to mammalian cells, filamentous phage can be easily loaded with drugs and directly delivered to the lesion location. In particular, chemical drugs can be conjugated on phage surface by chemical modification, and gene drugs can also be inserted into the genome of phage by recombinant DNA technology. Meanwhile, specific peptides/proteins displayed on the phage surface are able to conjugate with nanoparticles which will endow them specific-targeting and huge drug-loading capacity. Additionally, phage peptides/proteins can directly self-assemble into phage-mimetic nanoparticles which may be applied for self-navigating drug delivery nanovehicles. In this review, we summarize the production of phage particles, the identification of targeting peptides, and the recent applications of filamentous bacteriophages as well as their protein/peptide for targeting drug delivery in vitro and in vivo. The improvement of our understanding of filamentous bacteriophage and phage-mimetic nanoparticles will supply new tools for biotechnological approaches.

Polymeric filomicelles and nanoworms: two decades of synthesis and application

This review highlights the substantial progress in the syntheses and applications of filomicelles, an emerging nanomaterial with distinct and useful properties.

Emergence and Utility of Nonspherical Particles in Biomedicine

The importance of the size of targeted, spherical drug carriers has been previously explored and reviewed. Particle shape has emerged as an equally important parameter in determining the in vivo journey and efficiency of drug carrier systems. Researchers have invented techniques to better control the geometry of particles of many different materials, which have allowed for exploration of the role of particle geometry in the phases of drug delivery. The important biological processes include clearance by the immune system, trafficking to the target tissue, margination to the endothelial surface, interaction with the target cell, and controlled release of a payload. The review of current literature herein supports that particle shape can be altered to improve a system's targeting efficiency. Non-spherical particles can harness the potential of targeted drug carriers by enhancing targeted site accumulation while simultaneously decreasing side effects and mitigating some limitations faced by spherical carriers.

Oral delivery of nanoparticles containing anticancer SN38 and hSET1 antisense for dual therapy of colon cancer

An oral delivery system intended for treatment of colon cancer in HT29 cancerous cells was investigated by encapsulating hSET1 antisense and SN38 anticancer in nanoparticles based on cysteine trimethyl chitosan (cysTMC) and carboxymethyl dextran (CMD). Studies have shown hSET1 as the main type of histone methyltransferase (HMT) complex, is significantly overexpressed in malignant cells. In this study, hSET1 antisense was employed to inhibit gene expression. Additionally, SN38 was incorporated into nanoparticles to enhance the efficiency of the system by inhibition of topoisomerase 1. CysTMC was synthetized and characterized by (1)H NMR and FTIR. Nanoparticles were prepared through complexation of CMD and cysTMC. Particle size and surface charge was 100-150 nm and 17-21 mV respectively with drug content of around 2.6%. Gel electrophoresis assay proved the stability of antisense in simulated gastric and intestinal fluids. Nanoparticles showed high mucoadhesion and glutathione responsive release. Cellular uptake was observed by confocal microscopy and quantified by flow cytometry. Cytotoxicity of NPs was assessed using MTT assay. Results showed hSET1/SN38 nanoparticles had significantly higher cytotoxicity against HT29 cells compared with nanoparticles containing SN38, free SN38 or naked hSET1. Therefore, present system could be considered an effective combination therapy of highly hydrophobic SN38 and hSET1.

Assessing in vivo toxicity of graphene materials: current methods and future outlook

Graphene, a novel 2D carbon nanomaterial with unique properties, has attracted massive attention. Evaluating its toxicity is of great significance due to its potential applications in many fields, especially in biomedicine. In this review, the toxicity of graphene-based nanomaterials (GNMs) and related mechanisms at the molecular and cellular level, various approaches to evaluation of the in vivo toxicity of GNMs and major factors defining their toxicity will be discussed and summarized. This review will allow better understanding of the in vitro and in vivo toxicity of GNMs, which, we believe, may facilitate design and fabrication of novel, biocompatible and efficient GNM-based systems for biomedical applications.

Radioactive 198Au-doped nanostructures with different shapes for in vivo analyses of their biodistribution, tumor uptake, and intratumoral distribution

With Au nanocages as an example, we recently demonstrated that radioactive (198)Au could be incorporated into the crystal lattice of Au nanostructures for simple and reliable quantification of their in vivo biodistribution by measuring the γ radiation from (198)Au decay and for optical imaging by detecting the Cerenkov radiation. Here we extend the capability of this strategy to synthesize radioactive (198)Au nanostructures with a similar size but different shapes and then compare their biodistribution, tumor uptake, and intratumoral distribution using a murine EMT6 breast cancer model. Specifically, we investigated Au nanospheres, nanodisks, nanorods, and cubic nanocages. After PEGylation, an aqueous suspension of the radioactive Au nanostructures was injected into a tumor-bearing mouse intravenously, and their biodistribution was measured from the γ radiation while their tumor uptake was directly imaged using the Cerenkov radiation. Significantly higher tumor uptake was observed for the Au nanospheres and nanodisks relative to the Au nanorods and nanocages at 24 h postinjection. Furthermore, autoradiographic imaging was performed on thin slices of the tumor after excision to resolve the intratumoral distributions of the nanostructures. While both the Au nanospheres and nanodisks were only observed on the surfaces of the tumors, the Au nanorods and nanocages were distributed throughout the tumors.