Targeted Nano-drug Delivery Research Articles

Thrombolytic Agents: Nanocarriers in Targeted Release.

A thrombus, known as a blood clot, may form within the vascular system of the body and impede blood flow. Thrombosis is the most common underlying pathology of cardiovascular diseases, contributing to high morbidity and mortality. However, the main thrombolytic drugs (urokinase, streptokinase, etc.) have shortcomings, including a short half-life, serious side effects and a lack of targeting, that limit their clinical application. The use of nano-drug delivery systems is expected to address these problems and a variety of approaches, including biological and physical responsive systems, have been explored. In this report, recent advances in the development of targeted nano-drug delivery systems are thoroughly reviewed.

A Targeted Nano Drug Delivery System of AS1411 Functionalized Graphene Oxide Based Composites.

A novel method for the preparation of antitumor drug vehicles has been optimized. Biological materials of chitosan oligosaccharide (CO) and γ‐polyglutamic acid (γ‐PGA) have previously been employed as modifiers to covalently modify graphene oxide (GO), which in turn loaded doxorubicin (DOX) to obtain a nano drug delivery systems of graphene oxide based composites (GO‐CO‐γ‐PGA‐DOX). The system was not equipped with the ability of initiative targeting, thus resulting into toxicity and side effects on normal tissues or organs. In order to further improve the targeting property of the system, the nucleic acid aptamer NH2‐AS1411 (APT) of targeted nucleolin (C23) was used to conjugate on GO‐CO‐γ‐PGA to yield the targeted nano drug delivery system APT‐GO‐CO‐γ‐PGA. The structure, composition, dispersion, particle size and morphology properties of the synthesized complex have been studied using multiple characterization methods. Drug loading and release profile data showed that APT‐GO‐CO‐γ‐PGA is provided with high drug loading capacity and is capable of controlled and sustained release of DOX. Cell experimental results indicated that since C23 was overexpressed on the surface of Hela cells but not on the surface of Beas‐2B cells, APT‐GO‐CO‐γ‐PGA‐DOX can target Hela cells and make increase toxicity to Hela cells than Beas‐2B cells, and the IC50 value of APT‐GO‐CO‐γ‐PGA‐DOX was 3.23±0.04 μg/mL. All results proved that APT‐GO‐CO‐γ‐PGA can deliver antitumor drugs in a targeted manner, and achieve the effect of reducing poison, which indicated that the targeted carrier exhibits a broad application prospect in the field of biomedicine.

Revealing the Dynamic Mechanism by Which Transferrin Promotes the Cellular Uptake of HAIYPRH Peptide-Conjugated Nanostructures by Force Tracing.

The HAIYPRH (T7) peptide has been widely used as a ligand for constructing tumor-targeted nanodrug delivery systems since it can target the transferrin receptor (TfR) and then enter cells easily with the help of transferrin (Tf). However, the dynamic mechanism by which transferrin promotes the entry of T7-conjugated nanostructures into cells remains unclear. Herein, a force tracing technique based on atomic force microscopy (AFM) was used to track the ultrafast dynamic process of a T7-conjugated gold nanoparticle (AuNP-T7) entering a cell at the single-particle level in real time. Tf helped decrease the endocytosis force and increase the endocytosis speed of AuNP-T7 in A549 cells. However, Tf only increased the endocytosis speed of AuNP-T7 in HeLa cells. In contrast, in Vero cells without TfR overexpression, Tf decreased the endocytosis speed. This report provides important insights for redesigning and developing T7-conjugated nanodrug carriers in targeted nanodrug delivery systems.

Controlling Conjugated Antibodies at the Molecular Level for Active Targeting Nanoparticles toward HER2-Positive Cancer Cells.

For active targeting nanodrug delivery systems conjugated with antibodies, both lack of control of the antibody at the molecular level and protein corona formation remarkably decreases targeting efficacy. Herein, we designed a series of silica nanoparticles toward HER2-positive breast cancer cells, with an anti-HER2 Fab-6His density ranging from 50 to 180 molecules per nanoparticle. Through the site-directed immobilization method we developed, the antigen-binding domain of anti-HER2 Fab was mostly accessible to the HER2 receptor. Both polyethylene glycol (PEG) chains and a high density of Fab were shown to suppress protein corona formation and macrophage uptake. The dependency of targeting efficacy and cytotoxicity on Fab density was shown using a series of breast cancer cell lines with different levels of the HER2 expression. The high density of Fab stimulates quick responses from HER2-positive cells. Combined with PEG chains, conjugated antibodies with a well-controlled orientation and density significantly improves delivery performance and sheds light on the design and preparation of an improved active targeting nanodrug delivery system.

Metal Organic Frameworks (MOFs) as efficient carrier for targeted nanodrug delivery

A controllable and targeted drug delivery system development is imperative and important to reduce side effects and enhance the therapeutic efficacy of drugs. Metal-organic frameworks (MOFs), an emerging type of hybrid porous materials synthesized from metal ions or clusters abridged by organic linkers. They have attracted increasing attention in the recent years owing to the unique physical structures possessed, and the potential for wide range of applications. The superior properties of MOFs, such as well-defined pore aperture, tailorable composition and structure, tunable size, versatile functionality, high agent loading, and improved biocompatibility, have made them promising candidates as drug delivery hosts. MOFs for drug encapsulation and delivery is of great interest and many very promising results have been found, indicating that these porous solids exhibit several advantages over existing systems. This review highlights the recent advances in the synthesis, functionalization, and applications of MOFs in nanodrug delivery, and has classified them using drug loading strategies.

Direct Quantification of Drug Loading Content in Polymeric Nanoparticles by Infrared Spectroscopy.

Nanotechnology has enabled the development of novel therapeutic strategies such as targeted nanodrug delivery systems, control and stimulus-responsive release mechanisms, and the production of theranostic agents. As a prerequisite for the use of nanoparticles as drug delivery systems, the amount of loaded drug must be precisely quantified, a task for which two approaches are currently used. However, both approaches suffer from the inefficiencies of drug extraction and of the solid-liquid separation process, as well as from dilution errors. This work describes a new, reliable, and simple method for direct drug quantification in polymeric nanoparticles using attenuated total reflection Fourier transform infrared spectroscopy, which can be adapted for a wide variety of drug delivery systems. Silk fibroin nanoparticles and naringenin were used as model polymeric nanoparticle carrier and drug, respectively. The specificity, linearity, detection limit, precision, and accuracy of the spectroscopic approach were determined in order to validate the method. A good linear relation was observed within 0.00 to 7.89% of naringenin relative mass with an R2 of 0.973. The accuracy was determined by the spike and recovery method. The results showed an average 104% recovery. The limit of detection and limit of quantification of the drug loading content were determined to be 0.3 and 1.0%, respectively. The method’s robustness is demonstrated by the notable similarities between the calibrations carried out using two different equipment setups at two different institutions.

Targeted nano-drug delivery system for glioblastoma therapy: In vitro and in vivo study

This study developed polymeric nanoparticles (NPs) conjugated with monoclonal antibody (mAb) for glioblastoma treatment. In this study, the physicochemical properties of poly (butyl cyanoacrylate) (PBCA) NPs were characterized. The cytotoxicity of NPs conjugated with mAb (NPs + mAb) and in vitro drug release evaluation was tested on glioblastoma cell lines. Their therapeutic efficiency and side effects were then assessed in vivo in a rat model of glioblastoma. The conjugation of NPs to mAb revealed an average particle size of 365 nm and conjugation efficiency of 41.95%. The findings also showed that cytotoxicity was augmented by 40% compared to the free form of carboplatin. Moreover, in vivo studies showed that body weight remained relatively stable in rats treated by NPs + mAb and their survival time was longer (23.5 days) compared to rats treated with free carboplatin (19.5 days). In addition, ex vivo investigation showed that rats administered with NPs + mAb exhibited less side effects in the brain, kidney and liver compared to other groups.

Lyophilized Iron Oxide Nanoparticles Encapsulated in Amphotericin B: A Novel Targeted Nano Drug Delivery System for the Treatment of Systemic Fungal Infections.

We formulated and tested a targeted nanodrug delivery system to help treat life-threatening invasive fungal infections, such as cryptococcal meningitis. Various designs of iron oxide nanoparticles (IONP) (34–40 nm) coated with bovine serum albumin and coated and targeted with amphotericin B (AMB-IONP), were formulated by applying a layer-by-layer approach. The nanoparticles were monodispersed and spherical in shape, and the lead formulation was found to be in an optimum range for nanomedicine with size (≤36 nm), zeta potential (−20 mV), and poly dispersity index (≤0.2), and the drug loading was 13.6 ± 6.9 µg of AMB/mg of IONP. The drug release profile indicated a burst release of up to 3 h, followed by a sustained drug release of up to 72 h. The lead showed a time-dependent cellular uptake in C. albicans and C. glabrata clinical isolates, and exhibited an improved efficacy (16–25-fold) over a marketed conventional AMB-deoxycholate product in susceptibility testing. Intracellular trafficking of AMB-IONP by TEM and confocal laser scanning microscopy confirmed the successful delivery of the AMB payload at and/or inside the fungal cells leading to potential therapeutic advantages over the AMB-deoxycholate product. A short-term stability study at 5 °C and 25 °C for up to two months showed that the lyophilized form was stable.

Targeted Nano-Drug Delivery of Colchicine against Colon Cancer Cells by Means of Mesoporous Silica Nanoparticles.

Antimitotics are important anticancer agents and include the natural alkaloid prodrug colchicine (COL). However, a major challenge of using COL as an anticancer drug is its cytotoxicity. We developed a novel drug delivery system (DDS) for COL using mesoporous silica nanoparticles (MSNs). The MSNs were functionalized with phosphonate groups, loaded with COL, and coated with folic acid chitosan-glycine complex. The resulting nanoformulation, called MSNsPCOL/CG-FA, was tested for action against cancer and normal cell lines. The anticancer effect was highly enhanced for MSNsPCOL/CG-FA compared to COL. In the case of HCT116 cells, 100% inhibition was achieved. The efficiency of MSNsPCOL/CG-FA ranked in this order: HCT116 (colon cancer) > HepG2 (liver cancer) > PC3 (prostate cancer). MSNsPCOL/CG-FA exhibited low cytotoxicity (4%) compared to COL (~60%) in BJ1 normal cells. The mechanism of action was studied in detail for HCT116 cells and found to be primarily intrinsic apoptosis caused by an enhanced antimitotic effect. Furthermore, a contribution of genetic regulation (metastasis-associated lung adenocarcinoma transcript 1 (MALAT 1), and microRNA (mir-205)) and immunotherapy effects (angiopoietin-2 (Ang-2 protein) and programmed cell death protein 1 (PD-1) was found. Therefore, this study shows enhanced anticancer effects and reduced cytotoxicity of COL with targeted delivery compared to free COL and is a novel method of developing cancer immunotherapy using a low-cost small-molecule natural prodrug.

Advances in colon-targeted nano-drug delivery systems: challenges and solutions.

Nano-drug delivery systems (NDDS) for colon-targeted drug delivery are an active area of research on local diseases affecting the colon, such as ulcerative colitis, Crohn's disease, colon cancer, and for the delivery of peptide or protein drugs and vaccinations. In particular, targeted nano-drug delivery to the colon is advantageous for colon-specific diseases because nanoparticles can accumulate in diseased parts, improve the efficacies of therapeutics, and enable localized treatments, which reduces systemic toxicity. However, there are many hurdles, such as burst drug release, enzyme and acidic degradation of drug and carrier in the stomach, pH variations, mucus entrapment, and systemic uptake in the upper small intestine, which could challenge and compromise the successful delivery of NDDS to the colon. With advancements in NDDS, it may be possible to overcome these challenges leading to efficient drug delivery for colon-specific disorders. This review describes a few of the potential colon-specific drug delivery areas and the challenges faced by colon-targeted orally administered delivery systems, and provides an updated summary of recent advances in the development of orally administered NDDS for colon targeting, and the future advances in this research.

Extracellular matrix-penetrating nanodrill micelles for liver fibrosis therapy

As hepatic stellate cells (HSCs) are essential for hepatic fibrogenesis, HSCs targeted nano-drug delivery system is a research hotspot in liver fibrosis therapy. However, the excessive deposition of fibrosis collagen (mainly collagen I) in the space of Disse associated with hepatic fibrogenesis would significantly hinder nano-formulation delivery to HSCs. Here, we have prepared a collagenase I and retinol co-decorated polymeric micelle that possess nanodrill-like and HSCs-target function based on poly-(lactic-co-glycolic)-b-poly (ethylene glycol)-maleimide (PLGA-PEG-Mal) (named CRM) for liver fibrosis therapy. Upon encountering collagen I barrier, CRM exerted a nanodrill-like function, efficiently degrading pericellular collagen I and showing greater uptake by human HSCs than other micelle formulations. Besides, CRM could realize excellent accumulation in the fibrotic liver and accurate targeting to activated HSCs in mouse hepatic fibrosis model. Moreover, CRM loaded with nilotinib (CRM/NIL), a second-generation tyrosine kinase inhibitor used in the treatment of liver fibrosis, showed optimal antifibrotic activity. This work suggests that CRM with dual function is an efficient carrier for liver fibrosis drug delivery and collagenase I decorating could be a new strategy for building more efficient HSCs targeted nano-drug delivery system.

Efficient Navigation of Colloidal Robots in an Unknown Environment via Deep Reinforcement Learning

Equipping micro‐/nanoscale colloidal robots with artificial intelligence (AI) such that they can efficiently navigate in unknown complex environments can dramatically impact their use in emerging applications such as precision surgery and targeted nanodrug delivery. Herein, a model‐free deep reinforcement learning algorithm is developed that trains colloidal robots to efficiently navigate in unknown environments with random obstacles. A deep neural network architecture is used that enables the colloidal robots to mimic animal navigation decision‐making by directly processing raw sensor input and decomposing long‐range navigations to short‐range ones. The trained robot agents learn to make navigation decisions regarding both obstacle avoidance and travel time minimization, based solely on local sensory inputs without prior knowledge of the global environment. Such agents with biologically inspired mechanisms can acquire competitive navigation capabilities in large‐scale, complex environments containing obstacles of diverse shapes, sizes, and configurations. Herein, the potential of AI to enable colloidal robots in extensive applications is illustrated.

HPA aptamer functionalized paclitaxel-loaded PLGA nanoparticles for enhanced anticancer therapy through targeted effects and microenvironment modulation

Breast cancer is a fairly common cancer with high mortality in women worldwide. Targeted nano-drug delivery system for breast cancer treatment has achieved encouraging results, because of increased drug concentration at the tumor site, thereby improving biocompatibility and blood half-life while reducing chemoresistance. However, the absence of available target on cancer cells is one of the major obstacles for triple-negative breast cancer (TNBC). Increasing studies have shown that heparanase (HPA) is highly expressed in many cancers, including TNBC. Thus paclitaxel(PTX) -encapsulated PEGylated PLGA nanoparticles were developed and further surface-functionalized with the HPA aptamers (Apt(S1.5)-PTX-NP). Moreover, targeting and cytotoxicity of Apt(S1.5)-PTX-NP to TNBC cells were evaluated with MDA-MB-231 as a model. These nanoparticles bonded to the HPA overexpressed on the surface of TNBC cells and were taken up by these cells, resulting in remarkably enhanced cellular toxicity compared with non-targeted PTX-NP that lack the HPA aptamer (P < 0.01). Furthermore, Apt(S1.5)-PTX-NP significantly exhibited enhanced anti-invasive and superior anti-angiogenesis activity compared with those of other experiment groups at low administration dosage. The Apt(S1.5)-PTX-NP demonstrated the most dramatic efficacy with the final mean tumor sizes of 157.30 ± 41.09 mm3 (mean ± SD; n = 10) in vivo treatment. Thus, the present study indicated that HPA is a promising target for drug delivery to TNBC cells, and nanoparticle-HPA-aptamer bioconjugates can provide new insights for TNBC treatment.

Development of Zwitterionic Polypeptide Nanoformulation with High Doxorubicin Loading Content for Targeted Drug Delivery.

Much attention has been drawn to targeted nanodrug delivery systems due to their high therapeutic efficacy in cancer treatment. In this work, doxorubicin (DOX) was incorporated into a zwitterionic arginyl-glycyl-aspartic acid (RGD)-conjugated polypeptide by an emulsion solvent evaporation technique with high drug loading content (45%) and high drug loading efficiency (95%). This zwitterionic nanoformulation showed excellent colloidal stability at high dilution and in serum. The pH-induced disintegration and enzyme-induced degradation of the nanoformulation were confirmed by dynamic light scattering and gel permeation chromatography. Efficient internalization of DOX in the cells and high antitumor activity in vitro was observed. Compared with the free drug, this nanoformulation showed higher accumulation in tumor and lower systemic toxicity in vivo. The DOX-loaded zwitterionic RGD-conjugated polypeptide vesicles show potential application for targeted drug delivery in the clinic.

Transporter-Guided Delivery of Nanoparticles to Improve Drug Permeation across Cellular Barriers and Drug Exposure to Selective Cell Types.

Targeted nano-drug delivery systems conjugated with specific ligands to target selective cell-surface receptors or transporters could enhance the efficacy of drug delivery and therapy. Transporters are expressed differentially on the cell-surface of different cell types, and also specific transporters are expressed at higher than normal levels in selective cell types under pathological conditions. They also play a key role in intestinal absorption, delivery via non-oral routes (e.g., pulmonary route and nasal route), and transfer across biological barriers (e.g., blood–brain barrier and blood–retinal barrier. As such, the cell-surface transporters represent ideal targets for nano-drug delivery systems to facilitate drug delivery to selective cell types under normal or pathological conditions and also to avoid off-target adverse side effects of the drugs. There is increasing evidence in recent years supporting the utility of cell-surface transporters in the field of nano-drug delivery to increase oral bioavailability, to improve transfer across the blood–brain barrier, and to enhance delivery of therapeutics in a cell-type selective manner in disease states. Here we provide a comprehensive review of recent advancements in this interesting and important area. We also highlight certain key aspects that need to be taken into account for optimal development of transporter-assisted nano-drug delivery systems.

Transglutaminase mediated PEGylation of nanobodies for targeted nano-drug delivery.

Targeted delivery of anticancer drugs that selectively accumulate in malignant cells could enhance drug efficacy and reduce side effects of conventional chemotherapy. In this work, we designed a single domain antibody (nanobody) based drug delivery system for targeted delivery of anticancer drugs. An anti-EGFR nanobody (Nb) was constructed with a C3-tag and a Q-tag for site specific modifications under physiological conditions. The site specific PEGylation of the nanobody was achieved via a transglutaminase catalyzed reaction through the coupling of the Q-tag with PEG-NH2. As a proof of concept, the PEGylated nanobody was tethered to HSA coated upconversion nanoparticles (UCNPs) through the C3-tag, and an anticancer drug, doxorubicin (DOX), was loaded. Results showed that the Nb-conjugated drug delivery system exhibits superior specificity to the EGFR positive tumor cells. The drug delivery system is highly accumulated in the EGFR positive tumor cells (A431), whereas there was no detectable accumulation in the EGFR negative cells (MCF-7). Consequently, the drug loaded particles demonstrated significantly higher anti-proliferation to A431 cells than to MCF-7 cells. This work provides an effective approach for site-specific modification of nanobodies for the construction of targeted drug delivery systems.

Guiding nanomaterials to tumors for breast cancer precision medicine: from tumor-targeting small-molecule discovery to targeted nanodrug delivery

Precision medicine emphasizes patient-specific formulation for treatment of diseases, especially cancer. However, in targeted cancer treatment, because the expression level of tumor receptors in each patient varies even for the same type of cancer, the ligand/receptor-mediated approach does not seem promising for precision medicine. In this work, we demonstrated our strategy of using a phage display technique for breast cancer precision medicine. Using in vivo biopanning, we first selected an MCF-7 breast tumor-targeting peptide, then tested the effectiveness of the as-selected peptide in tumor homing and finally conjugated the peptide to a model photothermal drug, namely, gold nanorods, to achieve enhanced cancer killing efficacy. The peptides identified by the phage display technique can guide the drug to the tumors without the need to know the exact receptors on the tumor. This approach requires significantly less effort to explore patient-specific targeting molecules for precision medicine.

Folic acid armed Fe3O4-HPG nanoparticles as a safe nano vehicle for biomedical theranostics

Abstract Targeted nano drug delivery systems can be considered as in vivo tiny physicians that can accurately detect the disease location and prescribe drugs at the same time. In some cases, these skilled doctors are equipped with diagnostic agents that can monitor the treatment process. These nano-robots are known as nanotheranostic agents. The aim of this study is to inset folic acid armed polymeric core–shell iron oxide nanoparticles as a new type of nanotheranostic agent. Here, iron oxide nanoparticles were synthesized by polyol method and coated with hyperbranched polyglycerol. Different in vitro tests (cell viability and hemocompatibility) were conducted on the nanoparticles to evaluate their biocompatibility. Then they were decorated with folic acid as targeting agents and examined with different in vitro test to detect the influence of targeting on cell uptake properties. Results represented that this new type of nano-robot with size around 11 nanometer was biocompatible and had a positive effect on cellular uptake of nanoparticles. Thus, these nanoparticles could be used as potentially useful nanotheranostic systems to defeat cancer cells with high folate expression.

Co-delivery of sorafenib and siVEGF based on mesoporous silica nanoparticles for ASGPR mediated targeted HCC therapy

Combination with chemotherapeutic drug and gene therapy has been proven highly effective in suppressing tumor progression. Hence, an asialoglycoprotein receptor (ASGPR)-targeting nanodrug delivery system based on mesoporous silica (MSN) nanocarrier for co-delivery of sorafenib (SO) and vascular endothelial growth factor (VEGF) targeted siRNA (siVEGF) to hepatocellular carcinoma (HCC) was successfully designed and synthesized. The structure of nanoparticles was characterized by IR, particle size, zeta potential and N2 adsorption-desorption. The nanoparticles were further evaluated for drug release, cellular uptake, transfection, cell cytotoxicity and cell cycle against HepG2 and Huh7 cells. In vitro testing demonstrated that MSN-LA delivery system could not only induce S cell cycle arrest, enhance the cytotoxicity and improve the tumor target of SO and siVEGF, but also enhance the siVEGF transfection efficiency in ASGPR-overexpressing Huh7 cells. Overall, the MSN-LA delivery system can be a promising drug carrier which could further enhance the anti-cancer efficacy of SO and siVEGF via the active targeting property of LA.

Development of novel pH-sensitive thiolated chitosan/PMLA nanoparticles for amoxicillin delivery to treat Helicobacter pylori

The cysteine conjugated chitosan/PMLA multifunctional nanoparticles were synthesized as targeted Nano-drug delivery system to eradicate Helicobacter pylori. Helicobacter pylori specifically express urea transport protein on its membrane to carrying urea to the cytoplasm urease to supply ammonia that protects bacteria in the acid environment of the stomach. The clinical suitability of topical antimicrobial agents is required to get rid of Helicobacter pylori inside the inflamed basal region. In this work, cysteine conjugated chitosan derivative, Cys-CS for their mucoadhesive and anticoagulant properties was designed and synthesized, for the preparation of multifunctional nanoparticles. The technique turned into optimized to prepare Cys-CS/PMLA nanoparticles for encapsulation of amoxicillin. The results showed that amoxicillin-Cys-CS/PMLA nanoparticles exhibit favorable pH-sensitive properties that could procrastinate the release of amoxicillin at gastric acid and allow the drug to deliver and target to Helicobacter pylori at its survival region efficiently. In comparison with unmodified amoxicillin-chitosan/PMLA nanoparticles, effective inhibition of Helicobacter pylori growth was observed for amoxicillin-Cys-CS/PMLA nanoparticles. These results indicate that the multifunctional amoxicillin-loaded nanoparticles have great potential for the effective treatment of Helicobacter pylori infection. They can also be used as pharmacologically powerful nanocarriers for oral targeted delivery of different therapeutic drugs to treat Helicobacter pylori.