Dual-function theranostic nanoparticles for drug delivery and medical imaging contrast: perspectives and challenges for use in lung diseases

Nanoparticle-based platforms for targeted drug delivery to the pulmonary system as therapeutics to curb cystic fibrosis: A review

Cystic fibrosis (CF) is a genetic disorder of the respiratory system caused by mutation of the Cystic Fibrosis Trans-Membrane Conductance Regulator (CFTR) gene that affects a huge number of people worldwide. It results in difficulty breathing due to a large accumulation of mucus in the respiratory tract, resulting in serious bacterial infections, and subsequent death. Traditional drug-based treatments face hindered penetration at the site of action due to the thick mucus layer. Nanotechnology offers possibilities for developing advanced and effective treatment platforms by focusing on drugs that can penetrate the dense mucus layer, fighting against the underlying bacterial infections, and targeting the genetic cause of the disease. In this review, current nanoparticle-mediated drug delivery platforms for CF, challenges in therapeutics, and future prospects have been highlighted. The effectiveness of the different types of nano-based systems conjugated with various drugs to combat the symptoms and the challenges of treating CF are brought into focus. The toxic effects of these nano-medicines and the various factors that are responsible for their effectiveness are also highlighted.

Innovative Therapeutic Approaches Based on Nanotechnology for the Treatment and Management of Tuberculosis

Tuberculosis (TB), derived from bacterium named Mycobacterium tuberculosis, has become one of the worst infectious and contagious illnesses in the world after HIV/AIDS. Long-term therapy, a high pill burden, lack of compliance, and strict management regimens are disadvantages which resulted in the extensively drug-resistant (XDR) along with multidrug-resistant (MDR) in the treatment of TB. One of the main thrust areas for the current scenario is the development of innovative intervention tools for early diagnosis and therapeutics towards Mycobacterium tuberculosis (MTB). This review discusses various nanotherapeutic agents that have been developed for MTB diagnostics, anti-TB drugs and vaccine. Undoubtedly, the concept of employing nanoparticles (NPs) has strong potential in this therapy and offers impressive outcomes to conquer the disease. Nanocarriers with different types were designed for drug delivery applications via various administration methods. Controlling and maintaining the drug release might be an example of the benefits of utilizing a drug-loaded NP in TB therapy over conventional drug therapy. Furthermore, the drug-encapsulated NP is able to lessen dosage regimen and can resolve the problems of insufficient compliance. Over the past decade, NPs were developed in both diagnostic and therapeutic methods, while on the other hand, the therapeutic system has increased. These "theranostic" NPs were designed for nuclear imaging, optical imaging, ultrasound, imaging with magnetic resonance and the computed tomography, which includes both single-photon computed tomography and positron emission tomography. More specifically, the current manuscript focuses on the status of therapeutic and diagnostic approaches in the treatment of TB.

Tailoring Polymer-Based Nanoassemblies for Stimuli-Responsive Theranostic Applications

Polymer assemblies on the nanoscale represent a powerful toolbox for the design of theranostic systems when combined with both therapeutic compounds and diagnostic reporting ones. Here, recent advances in the design of theranostic systems for various diseases, containing-in their architecture-either polymers or polymer assemblies as one of the building blocks are presented. This review encompasses the general principles of polymer self-assembly, from the production of adequate copolymers up to supramolecular assemblies with theranostic functionality. Such polymer nanoassemblies can be further tailored through the incorporation of inorganic nanoparticles to endow them with multifunctional therapeutic and/or diagnostic features. Systems that change their architecture or properties in the presence of stimuli are selected, as responsivity to changes in the environment is a key factor for enhancing efficiency. Such theranostic systems are based on the intrinsic properties of copolymers or one of the other components. In addition, systems with a more complex architecture, such as multicompartments, are presented. Selected systems indicate the advantages of such theranostic approaches and provide a basis for further developments in the field.

Radiolabeling strategies and pharmacokinetic studies for metal based nanotheranostics

Radiolabeled metal-based nanoparticles (MNPs) have drawn considerable attention in the fields of nuclear medicine and molecular imaging, drug delivery, and radiation therapy, given the fact that they can be potentially used as diagnostic imaging and/or therapeutic agents, or even as theranostic combinations. Here, we present a systematic review on recent advances in the design and synthesis of MNPs with major focuses on their radiolabeling strategies and the determinants of their in vivo pharmacokinetics, and together how their intended applications would be impacted. For clarification, we categorize all reported radiolabeling strategies for MNPs into indirect and direct approaches. While indirect labeling simply refers to the use of bifunctional chelators or prosthetic groups conjugated to MNPs for post-synthesis labeling with radionuclides, we found that many practical direct labeling methodologies have been developed to incorporate radionuclides into the MNP core without using extra reagents, including chemisorption, radiochemical doping, hadronic bombardment, encapsulation, and isotope or cation exchange. From the perspective of practical use, a few relevant examples are presented and discussed in terms of their pros and cons. We further reviewed the determinants of in vivo pharmacokinetic parameters of MNPs, including factors influencing their in vivo absorption, distribution, metabolism, and elimination, and discussed the challenges and opportunities in the development of radiolabeled MNPs for in vivo biomedical applications. Taken together, we believe the cumulative advancement summarized in this review would provide a general guidance in the field for design and synthesis of radiolabeled MNPs towards practical realization of their much desired theranostic capabilities. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Diagnostic Nanodevices Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Thermo-responsive Fluorescent Nanoparticles for Multimodal Imaging and Treatment of Cancers

Theranostic systems capable of delivering imaging and therapeutic agents at a specific target are the focus of intense research efforts in drug delivery. To overcome non-degradability and toxicity concerns of conventional theranostic systems, we formulated a novel thermo-responsive fluorescent polymer (TFP) and conjugated it on the surface of iron oxide magnetic nanoparticles (MNPs) for imaging and therapeutic applications in solid tumors. Methods: TFP-MNPs were synthesized by copolymerizing poly(N-isopropylacrylamide), allylamine and a biodegradable photoluminescent polymer, and conjugating it on MNPs via a free radical polymerization reaction. Physicochemical properties of the nanoparticles were characterized using Fourier transform infrared spectroscopy, dynamic light scattering, and vibrational sample magnetometry. Nanoparticle cytocompatibility, cellular uptake and cytotoxicity were evaluated using in vitro cell assays. Finally, in vivo imaging and therapeutic efficacy studies were performed in subcutaneous tumor xenograft mouse models. Results: TFP-MNPs of ~135 nm diameter and -31 mV ζ potential maintained colloidal stability and superparamagnetic properties. The TFP shell was thermo-responsive, fluorescent, degradable, and released doxorubicin in response to temperature changes. In vitro cell studies showed that TFP-MNPs were compatible to human dermal fibroblasts and prostate epithelial cells. These nanoparticles were also taken up by prostate and skin cancer cells in a dose-dependent manner and exhibited enhanced killing of tumor cells at 41°C. Preliminary in vivo studies showed theranostic capabilities of the nanoparticles with bright fluorescence, MRI signal, and therapeutic efficacy under magnetic targeting after systemic administration in tumor bearing mice. Conclusion: These results indicate the potential of TFP-MNPs as multifunctional theranostic nanoparticles for various biological applications, including solid cancer management.

SPIONs/3D SiSBA-16 based Multifunctional Nanoformulation for target specific cisplatin release in colon and cervical cancer cell lines

Multifunctional nanomaterials can be used for dual applications: drug delivery as well as in bioimaging. In current study, we investigated potential use of silica based supports; 3D cage type SiSBA-16 (S-16), monodispersed hydrophilic spherical silica (HYPS) and mesocellular foam (MSU-F) for cisplatin (Cp) delivery. To obtain magnetic resonance characteristics, 10 wt% iron oxide was loaded through enforced adsorption technique. For pH stimuli responsive release of Cp, 10 wt%SPIONs/S-16 was functionalized with 3-(Aminopropyl)triethoxysilane (A) and poly acrylic acid (PAA) termed as 10 wt%SPIONs/S-16-A-Cp and 10 wt%SPIONs/S-16-APAA-Cp. By TEM analysis, the average diameter of the SPIONs was found to range between 10–60 nm. VSM analysis showed saturation magnetization over S-16, HYPS and MSU-F were in the following order: 10 wt%SPIONs/HYPS (4.08 emug⁻¹) > 10 wt%SPIONs /S-16 (2.39 emug⁻¹) > 10 wt%SPIONs/MSU-F (0.23 emug⁻¹). Cp release study using dialysis membrane in PBS solution over 10 wt%SPIONs/S-16 nanoformulations showed highest cumulative release (65%) than 10 wt%SPIONs/MSU-F-A-Cp (63%), 10 wt%SPIONs/HYPS-A-Cp (58%), and Cp-F127/S-16 (53%), respectively. 10 wt%SPIONs/S-16-A-Cp and 10 wt%SPIONs/S-16-APAA-Cp were evaluated for in vitro target anticancer efficiency in human cancer cell lines (colon cancer (HCT 116), cervical cancer (HeLa)) and normal cells (Human embryonic kidney cells (HEK293) using MTT and DAPI staining. 10 wt%SPIONs/S-16-A-Cp treated Hela and HCT116 cancerous cell lines showed significant control of cell growth, apoptotic activity and less cytotoxic effect as compared to Cp and 10 wt%SPIONs/S-16. Target specific Cp release in the cells shows that 10 wt%SPIONs/S-16-A-Cp can be easily upgraded for magnetic resonance imaging capability.

Challenge in particle delivery to cells in a microfluidic device

Micro and nanotechnology can potentially revolutionize drug delivery systems. Novel microfluidic systems have been employed for the cell culture applications and drug delivery by micro and nanocarriers. Cells in the microchannels are under static and dynamic flow perfusion of culture media that provides nutrition and removes waste from the cells. This exerts hydrostatic and hydrodynamic forces on the cells. These forces can considerably affect the functions of the living cells. In this paper, we simulated the flow of air, culture medium, and the particle transport and deposition in the microchannels under different angles of connection inlet. It was found that the shear stress induced by the medium culture flow is not so high to damage the cells and that it is roughly uniform in the cell culture section (CCS). However, the local shear stresses in the other parts of the microchip differ by changing the angles of the connection inlet. The results showed that the particle deposition was a function of the particle size, the properties of the fluid, and the flow rate. At a lower air flow rate, both small and large particles deposited in the entrance region and none of them reached the CCS. Once the airflow rate increased, the drag of the flow could overcome the diffusion of the small particles and deliver them to the CCS so that more than 88% of the 100 nm and 98% of the 200 nm particles deposited in the CCS. However, larger particles with average diameters in micrometers could not reach the CCS by the airflow even at high flow rate. In contrast, our findings indicated that both small and large particles could be delivered to the CCS by liquid flow. Our experimental data confirm that microparticles (with diameters of 5 and 20 μm) suspended in a liquid can reach the CCS at a well-adjusted flow rate. Consequently, a liquid carrier is suggested to transport large particles through microchannels. As a powerful tool, these numerical simulations provide a nearly complete understanding of the flow field and particle patterns in microchips which can significantly lower the trial and error in the experiment tests and accordingly save researchers considerable cost and time for drug delivery to the cell in the microchip by micro/nanocarriers.

Doxorubicin-loaded protease-activated near-infrared fluorescent polymeric nanoparticles for imaging and therapy of cancer

INTRODUCTION

Despite significant progress in the field of oncology, cancer remains one of the leading causes of death. Chemotherapy is one of the most common treatment options for cancer patients but is well known to result in off-target toxicity. Theranostic nanomedicines that integrate diagnostic and therapeutic functions within an all-in-one platform can increase tumor selectivity for more effective chemotherapy and aid in diagnosis and monitoring of therapeutic responses.

MATERIAL AND METHODS

In this work, theranostic nanoparticles were synthesized with commonly used biocompatible and biodegradable polymers and used as cancer contrast and therapeutic agents for optical imaging and treatment of breast cancer. These core-shell nanoparticles were prepared by nanoprecipitation of blends of the biodegradable and biocompatible amphiphilic copolymers poly(lactic-co-glycolic acid)-b-poly-l-lysine and poly(lactic acid)-b-poly(ethylene glycol). Poly-l-lysine in the first copolymer was covalently decorated with near-infrared fluorescent Alexa Fluor 750 molecules.

RESULTS

The spherical nanoparticles had an average size of 60-80 nm. The chemotherapeutic drug doxorubicin was encapsulated in the core of nanoparticles at a loading of 3% (w:w) and controllably released over a period of 30 days. A 33-fold increase in near-infrared fluorescence, mediated by protease-mediated cleavage of the Alexa Fluor 750-labeled poly-l-lysine on the surface of the nanoparticles, was observed upon interaction with the model protease trypsin. The cytocompatibility of drug-free nanoparticles and growth inhibition of drug-loaded nanoparticles on MDA-MB-231 breast cancer cells were investigated with a luminescence cell-viability assay. Drug-free nanoparticles were found to cause minimal toxicity, even at high concentrations (0.2-2,000 µg/mL), while doxorubicin-loaded nanoparticles significantly reduced cell viability at drug concentrations >10 µM. Finally, the interaction of the nanoparticles with breast cancer cells was studied utilizing fluorescence microscopy, demonstrating the potential of the nanoparticles to act as near-infrared fluorescence optical imaging agents and drug-delivery carriers.

CONCLUSION

Doxorubicin-loaded, enzymatically activatable nanoparticles of less than 100 nm were prepared successfully by nanoprecipitation of copolymer blends. These nanoparticles were found to be suitable as controlled drug delivery systems and contrast agents for imaging of cancer cells.

Nanobiotechnology medical applications: Overcoming challenges through innovation

Biomedical Nanotechnology (BNT) has rapidly become a revolutionary force that is driving innovation in the medical field. BNT is a subclass of nanotechnology (NT), and often operates in cohort with other subclasses, such as mechanical or electrical NT for the development of diagnostic assays, therapeutic implants, nano-scale imaging systems, and medical machinery. BNT is generating solutions to many conventional challenges through the development of enhanced therapeutic delivery systems, diagnostic techniques, and theranostic therapies. Therapeutically, BNT has generated many novel nanocarriers (NCs) that each express specifically designed physiochemical properties that optimize their desired pharmacokinetic profile. NCs are also being integrated into nanoscale platforms that further enhance their delivery by controlling and prolonging their release profile. Nano-platforms are also proving to be highly efficient in tissue regeneration when combined with the appropriate growth factors. Regarding diagnostics, NCs are being designed to perform targeted delivery of luminescent tags and contrast agents that enhance the NC -aided imaging capabilities and resulting diagnostic accuracy of the presence of diseased cells. This technology has also been advancing the ability for surgeons to practice true precision surgical techniques. Incorporating therapeutic and diagnostic NC-components within a single NC can facilitate both functions, referred to as theranostics, which facilitates real-time in vivo tracking and observation of drug release events via enhanced imaging. Additionally, stimuli-responsive theranostic NCs are quickly developing as vectors for tumor ablation therapies by providing a model that facilitates the location of cancer cells for the application of an external stimulus. Overall, BNT is an interdisciplinary approach towards health care, and has the potential to significantly improve the quality of life for humanity by significantly decreasing the treatment burden for patients, and by providing non-invasive therapeutics that confer enhanced therapeutic efficiency and safety

Correction to: Characterization of the first fully human anti-TEM1 scFv in models of solid tumor imaging and immunotoxin-based therapy

Tumor endothelial marker 1 (TEM1) has been identified as a novel surface marker upregulated on the blood vessels and stroma in many solid tumors. We previously isolated a novel single-chain variable fragment (scFv) 78 against TEM1 from a yeast display scFv library. Here we evaluated the potential applications of scFv78 as a tool for tumor molecular imaging, immunotoxin-based therapy and nanotherapy. Epitope mapping, three-dimensional (3D) structure docking and affinity measurements indicated that scFv78 could bind to both human and murine TEM1, with equivalent affinity, at a well-conserved conformational epitope. The rapid internalization of scFv78 and scFv78-labeled nanoparticles was triggered after specific TEM1 binding. The scFv78-saporin immunoconjugate also exerted dose-dependent cytotoxicity with high specificity to TEM1-positive cells in vitro. Finally, specific and sensitive tumor localization of scFv78 was confirmed with optical imaging in a mouse tumor model that has highly endogenous mTEM1 expression in the vasculature. Our data indicate that scFv78, the first fully human anti-TEM1 recombinant antibody, recognizes both human and mouse TEM1 and has unique and favorable features that are advantageous for the development of imaging probes or antibody-toxin conjugates for a large spectrum of human TEM1-positive solid tumors.

Sertoli Cells Loaded with Doxorubicin in Lipid Micelles Reduced Tumor Burden and Dox-Induced Toxicity

The toxic side effects of doxorubicin (Dox) limit its long-term use as a lung cancer chemotherapeutic. Additionally, drug delivery to the deep lung is challenging. To address these challenges, isolated rat Sertoli cells (SCs) were preloaded with Dox conjugated to lipid micelle nanoparticles (SC-DLMNs) and delivered to mouse lungs. These immunocompetent cells, when injected intravenously, travel to the lung, deliver the payload, and get cleared by the system quickly without causing any adverse reaction. We observed that SC-DLMNs effectively treated Lewis lung carcinoma 1-induced lung tumors in mice and the drug efficacy was comparable to SC-Dox treatment. Mice treated with SC-DLMNs also showed significantly less toxicity compared to those treated with SC-Dox. The encapsulation of Dox in lipid micelle nanoparticles reduced the toxicity of Dox and the SC-based delivery method ensured drug delivery to the deep lung without evoking any immune response. Taken together, these results provide a novel SC-based nanoparticle drug delivery method for improved therapeutic outcome of cardiotoxic antilung cancer drugs.

Characterization of the first fully human anti-TEM1 scFv in models of solid tumor imaging and immunotoxin-based therapy

Tumor endothelial marker 1 (TEM1) has been identified as a novel surface marker upregulated on the blood vessels and stroma in many solid tumors. We previously isolated a novel single-chain variable fragment (scFv) 78 against TEM1 from a yeast display scFv library. Here, we evaluated the potential applications of scFv78 as a tool for tumor molecular imaging, immunotoxin-based therapy and nanotherapy. Epitope mapping, three-dimensional structure docking and affinity measurements indicated that scFv78 could bind to both human and murine TEM1, with equivalent affinity, at a well-conserved conformational epitope. The rapid internalization of scFv78 and scFv78-labeled nanoparticles was triggered after specific TEM1 binding. The scFv78-saporin immunoconjugate also exerted dose-dependent cytotoxicity with high specificity to TEM1-positive cells in vitro. Finally, specific and sensitive tumor localization of scFv78 was confirmed with optical imaging in a tumor mouse model that has highly endogenous mTEM1 expression in the vasculature. Our data indicated that scFv78, the first fully human anti-TEM1 recombinant antibody, recognizes both human and mouse TEM1 and has unique and favorable features that are advantageous for the development of imaging probes or antibody-toxin conjugates for a large spectrum of human TEM1-positive solid tumors.

Magnetic Resonance Imaging of Human-Derived Amniotic Membrane Stem Cells Using PEGylated Superparamagnetic Iron Oxide Nanoparticles

OBJECTIVE

The label and detection of cells injected into target tissues is an area of focus for researchers. Iron oxide nanoparticles can be used to label cells as they have special characteristics. The purpose of this study is to examine the effects of iron oxide nanoparticles on human-derived amniotic membrane stem cell (hAMCs) survival and to investigate the magnetic properties of these nanoparticles with increased contrast in magnetic resonance imaging (MRI).

MATERIALS AND METHODS

In this experimental study, we initially isolated mesenchymal stem cells from amniotic membranes and analyzed them by flow cytometry. In addition, we synthesized superparamagnetic iron oxide nanoparticles (SPIONs) and characterized them by various methods. The SPIONs were incubated with hAMCs at concentrations of 25-800 μg/mL. The cytotoxicity of nanoparticles on hAMCs was measured by the MTT assay. Next, we evaluated the effectiveness of the magnetic nanoparticles as MRI contrast agents. Solutions of SPION were prepared in water at different iron concentrations for relaxivity measurements by a 1.5 Tesla clinical MRI instrument.

RESULTS

The isolated cells showed an adherent spindle shaped morphology. Polyethylene glycol (PEG)-coated SPIONs exhibited a spherical morphology. The average particle size was 20 nm and magnetic saturation was 60 emu/g. Data analysis showed no significant reduction in the percentage of viable cells (97.86 ± 0.41%) after 72 hours at the 125 μg/ml concentration compared with the control. The relaxometry results of this SPION showed a transverse relaxivity of 6.966 (μg/ml.s)(-1).

CONCLUSION

SPIONs coated with PEG used in this study at suitable concentrations had excellent labeling efficiency and biocompatibility for hAMCs.

Lung cancer nanomedicine: potentials and pitfalls

Lung cancer is by far the most common cause of cancer-related deaths in the world. Nanoparticle-based therapies enable targeted drug delivery for lung cancer treatment with increased therapeutic efficiency and reduced systemic toxicity. At the same time, nanomedicine has the potential for multimodal treatment of lung cancer that may involve 'all-in-one' targeting of several tumor-associated cell types in a timely and spatially controlled manner. Therapeutic approaches, however, are hampered by a translational gap between basic scientists, clinicians and pharma industry due to suboptimal animal models and difficulties in scale-up production of nanoagents. This calls for a disease-centered approach with interdisciplinary basic and clinical research teams with the support of pharma industries.

Polymeric multifunctional nanomaterials for theranostics

Various applications of polymeric multifunctional nanomaterials for theranostics.

Blood protein coating of gold nanoparticles as potential tool for organ targeting

Nanoparticles (NP) and nanoparticulated drug delivery promise to be the breakthrough for therapy in medicine but raise concerns in terms of nanotoxicity. We present quantitative murine biokinetics assays using polyelectrolyte-multilayer-coated gold NP (AuNP, core diameter 15 and 80 nm; (198)Au radio-labeled). Those were stably conjugated either with human serum albumin (alb-AuNP) or apolipoprotein E (apoE-AuNP), prior to intravenous injection. We compare the biokinetics of protein-AuNP-conjugates with citrate-stabilized AuNP (cit-AuNP). Biokinetics was complemented with histology in organs with high AuNP content using 15 nm double fluorescently-labeled alb-AuNP-conjugates. Protein conjugation massively reduced liver retention (alb-AuNP: 52%, apoE-AuNP: 72%, cit-AuNP: >95%, at 19 h and 48 h) when compared to cit-AuNP. The protein conjugates were retained in lungs (alb-AuNP (18%) and spleen (alb-AuNP (16%), apoE-AuNP (21%) at 19 h. Alb-AuNP show significantly increased fractions in lungs (factors: 60 (30 min); 111 (19 h); 235 (48 h) and brain (factors: 70 (30 min); 90 (19 h); >200 (48 h) compared to cit-AuNP (control) - or even to apoE-AuNP. The influence of protein conjugation on the biodistribution disappears for 80 nm AuNP comparing to control. Histologically, the 15 nm alb-AuNP are mainly located in the endothelium of brain, lungs, liver and kidneys after 30 min, while at 19 h they moved deeper into the parenchyma e.g. in hippocampus. Our study clearly suggests that stable conjugation of AuNP with albumin and apoE prior to intravenous administration increases specificity and efficiency of NP in diseased target-organs thus suggesting a potential role in nanomedicine and nanopharmacology.