Biodistribution of fluoresceinated dextran using novel nanoparticles evading reticuloendothelial system

Design of nanoparticle-based systems for the systemic delivery of chemotherapeutics: Alternative potential routes via sublingual and buccal administration for systemic drug delivery

Conventional therapeutic approaches for cancer generally involve chemo- and radiation therapies that often exhibit low efficacy and induce toxic side effects. Recent years have seen significant advancements in the use of protein biologics as a promising alternative treatment option. Nanotechnology-based systems have shown great potential in providing more specific and targeted cancer treatments, thus improving upon many of the limitations associated with current treatments. The unique properties of biomaterial carriers at the nanoscale have been proven to enhance both the performance of the incorporated therapeutic agent and tumor targeting; however, many of these systems are delivered intravenously, which can cause hazardous side effects. Buccal and sublingual delivery systems offer an alternative route for more efficient delivery of nanotechnologies and drug absorption into systemic circulation. This review concentrates on emerging buccal and sublingual nanoparticle delivery systems for chemo- and protein therapeutics, their development, efficacy, and potential areas of improvement in the field. Several factors contribute to the development of effective buccal or sublingual nanoparticle delivery systems, including targeting efficiency of the nanoparticulate carriers, drug release, and carrier biocompatibility. Furthermore, the potential utilization of buccal and sublingual multilayer films combined with nanoparticle chemotherapeutic systems is outlined as a future avenue for in vitro and in vivo research.

Perspectives on cutting-edge nanoparticulate drug delivery technologies based on lipids and their applications

Numerous nanotech arenas in therapeutic biology have recently provided a scientific platform to manufacture a considerable swath of unique chemical entities focusing on drugs. Recently, nanoparticulate drug delivery systems have emerged to deliver a specific drug to a specified site. Among all other carriers, lipids possess features exclusive to nanostructured dosage forms. The bioavailability of orally administered drugs is typically negatively affected by their poor water solubility, resulting from the unique chemical moieties introduced. Because of their unique advantages, lipid nanoparticles must become increasingly predictable as a robust delivery mechanism. The enhanced biopharmaceutical properties and significance of lipid-based targeting technologies such as liposomes, niosomes, solid lipid nanoparticles and micelles are highlighted in this review. Pharmaceutical implications of lipid nanocarriers for the transport and distribution of various therapeutic agents, such as biotechnological products and small pharmaceutical molecules, is a booming topic. Lipid nanoparticles as drug delivery systems have many appealing properties, including high biocompatibility, ease of preparation, tissue specificity, avoidance of reticuloendothelial systems, delayed drug release, scale-up feasibility, nontoxicity and targeted delivery. The use of lipid nanoparticles to enhance the transport of biopharmaceuticals is currently considered state-of-the-art. Similarly, we critically examine the upcoming guidelines that therapeutic scientists should handle.

In Vivo Fluorescence Molecular Imaging Using Covalent Organic Nanosheets Without Labeling

Organic nanomaterials, as nanocarrier platforms, have tremendous potential for biomedical applications. The authors successfully prepared novel two-dimensional covalent organic nanosheets (CONs) that can be used as efficient in vivo bioimaging probes by condensing 1,3,5-triformylglucinol (Tp) and 2,7-diaminopyrene (Py) to produce TpPy covalent organic frameworks (COFs). TpPy COFs are then subjected to a liquid exfoliation process to obtain TpPy CONs (< 200 nm in size and < 1.7 nm in thickness). TpPy CONs disperse well in water to provide a stable, homogeneous colloidal suspension, which shows favorable photoluminescence properties. Cell viability tests using MDA-MB-231 and RAW 264.7 cells reveal that TpPy CONs are low in cytotoxicity. Confocal microscopy reveals clear fluorescent cell images after incubation with TpPy CONs for 24 h, without reduction in cell activity or cytosolic aggregation. To investigate the biological behavior of the TpPy CONs, the authors perform an in vivo fluorescence imaging study using MDA-MB-231 tumor-bearing mice. After intravenous injection of TpPy CONs disperse in phosphate-buffered saline (PBS), persistent and strong fluorescence signals are observed in the tumor region, with low background signals from normal tissues at 1, 3, 12, and 24 h after injection. Furthermore, these in vivo imaging results concurred with ex vivo biodistribution and histological results.

Pilot scale production and characterization of next generation high molecular weight and tense quaternary state polymerized human hemoglobin

Polymerized human hemoglobin (PolyhHb) is being studied as a possible red blood cell (RBC) substitute for use in scenarios where blood is not available. While the oxygen (O2 ) carrying capacity of PolyhHb makes it appealing as an O2 therapeutic, the commercial PolyhHb PolyHeme® (Northfield Laboratories Inc.) was never approved for clinical use due to the presence of large quantities of low molecular weight (LMW) polymeric hemoglobin (Hb) species (<500 kDa), which have been shown to elicit vasoconstriction, systemic hypertension, and oxidative tissue injury in vivo. Previous bench-top scale studies in our lab demonstrated the ability to synthesize and purify PolyhHb using a two-stage tangential flow filtration purification process to remove almost all undesirable Hb species (>0.2 µm and <500 kDa) in the material, to create a product that should be safer for transfusion. Therefore, to enable future large animal studies and eventual human clinical trials, PolyhHb synthesis and purification processes need to be scaled up to the pilot scale. Hence in this study, we describe the pilot scale synthesis and purification of PolyhHb. Characterization of pilot scale PolyhHb showed that PolyhHb could be successfully produced to yield biophysical properties conducive for its use as an RBC substitute. Size exclusion high performance liquid chromatography showed that pilot scale PolyhHb yielded a high molecular weight Hb polymer containing a small percentage of LMW Hb species (<500 kDa). Additionally, the auto-oxidation rate of pilot scale PolyhHb was even lower than that of previous generations of PolyhHb. Taken together, these results demonstrate that PolyhHb has the ability to be seamlessly manufactured at the pilot scale to enable future large animal studies and clinical trials.

Functionalization strategies of polymeric nanoparticles for drug delivery in Alzheimer's disease: Current trends and future perspectives

Alzheimer's disease (AD), the most common form of dementia, is a progressive and multifactorial neurodegenerative disorder whose primary causes are mostly unknown. Due to the increase in life expectancy of world population, including developing countries, AD, whose incidence rises dramatically with age, is at the forefront among neurodegenerative diseases. Moreover, a definitive cure is not yet within reach, imposing substantial medical and public health burdens at every latitude. Therefore, the effort to devise novel and effective therapeutic strategies is still of paramount importance. Genetic, functional, structural and biochemical studies all indicate that new and efficacious drug delivery strategies interfere at different levels with various cellular and molecular targets. Over the last few decades, therapeutic development of nanomedicine at preclinical stage has shown to progress at a fast pace, thus paving the way for its potential impact on human health in improving prevention, diagnosis, and treatment of age-related neurodegenerative disorders, including AD. Clinical translation of nano-based therapeutics, despite current limitations, may present important advantages and innovation to be exploited in the neuroscience field as well. In this state-of-the-art review article, we present the most promising applications of polymeric nanoparticle-mediated drug delivery for bypassing the blood-brain barrier of AD preclinical models and boost pharmacological safety and efficacy. In particular, novel strategic chemical functionalization of polymeric nanocarriers that could be successfully employed for treating AD are thoroughly described. Emphasis is also placed on nanotheranostics as both potential therapeutic and diagnostic tool for targeted treatments. Our review highlights the emerging role of nanomedicine in the management of AD, providing the readers with an overview of the nanostrategies currently available to develop future therapeutic applications against this chronic neurodegenerative disease.

Application of chitosan nanoparticles in skin wound healing

The rising prevalence of impaired wound healing and the consequential healthcare burdens have gained increased attention over recent years. This has prompted research into the development of novel wound dressings with augmented wound healing functions. Nanoparticle (NP)-based delivery systems have become attractive candidates in constructing such wound dressings due to their various favourable attributes. The non-toxicity, biocompatibility and bioactivity of chitosan (CS)-based NPs make them ideal candidates for wound applications. This review focusses on the application of CS-based NP systems for use in wound treatment. An overview of the wound healing process was presented, followed by discussion on the properties and suitability of CS and its NPs in wound healing. The wound healing mechanisms exerted by CS-based NPs were then critically analysed and discussed in sections, namely haemostasis, infection prevention, inflammatory response, oxidative stress, angiogenesis, collagen deposition, and wound closure time. The results of the studies were thoroughly reviewed, and contradicting findings were identified and discussed. Based on the literature, the gap in research and future prospects in this research area were identified and highlighted. Current evidence shows that CS-based NPs possess superior wound healing effects either used on their own, or as drug delivery vehicles to encapsulate wound healing agents. It is concluded that great opportunities and potentials exist surrounding the use of CSNPs in wound healing.

Tumor-specific activatable biopolymer nanoparticles stabilized by hydroxyethyl starch prodrug for self-amplified cooperative cancer therapy

Rationale: Chemodynamic therapy (CDT) is an emerging tumor-specific therapeutic strategy. However, the anticancer activity of CDT is impeded by the insufficient Fenton catalytic efficiency and the high concentration of glutathione (GSH) in the tumor cells. Also, it is challenging to eliminate tumors with CDT alone. Thus, simple strategies aimed at constructing well-designed nanomedicines that can improve therapeutic efficiency of CDT and simultaneously incorporate extra therapeutic modes as helper are meaningful and highly required. Method: Tailored to specific features of tumor microenvironment (TME), in this study, we developed a biosafe, stable and TME-activated theranostic nanoplatform (P(HSD-Cu-DA)) for photoacoustic imaging (PAI) and self-amplified cooperative therapy. This intelligent nanoplatform was fabricated following a simple one-pot coordination and polymerization strategy by using dopamine and Cu²⁺ as precursors and redox-responsive hydroxyethyl starch prodrugs (HES-SS-DOX) as stabilizer. Results: Interestingly, the pre-doped Cu²⁺ in polydopamine (PDA) framework can endow P(HSD-Cu-DA) NPs with tumor-specific CDT ability and remarkably enhance NIR absorption of PDA. PAI and biodistribution tests proved such nanoplatform can effectively accumulate in tumor tissues. Following enrichment, massive amounts of toxic hydroxyl radicals (·OH, for CDT) and free DOX (for chemotherapy) were generated by the stimulation of TME, which was further boosted by local hyperthermia. Concomitantly, in the process of activating these therapeutic functions, GSH depletion triggered by disulfide bond (-SS-) breakage and Cu²⁺ reduction within tumor cells occurred, further amplifying intratumoral oxidative stress. Importantly, the framework structure dominated by bioinspired polydopamine and clinical-used HES guaranteed the long-term biosafety of in vivo treatment. As a result, the mutual promotion among different components yields a potent tumor suppression outcome and minimized systemic toxicity, with one dosage of drug administration and laser irradiation, respectively. Conclusion: This work provides novel insights into designing efficient and tumor-specific activatable nanotherapeutics with significant clinical translational potential for cancer therapy.

Fabrication of poly(t-butyl betaine carboxylate)-based nanoparticles and study on their in vivo biosecurity

The purpose of this article was to fabricate the novel poly(t-butyl betaine carboxylate)-S-S-poly (1, 3-dioxan-2-one) nanoparticles (PCB-tBU-S-S-PDI NPs) and study their in vivo biosecurity. The poly(t-butyl betaine carboxylate) (PCB-tBU) segment was conjugated to the poly(1, 3-dioxan-2-one)(PDI) moity with a disulfide bond to obtain the copolymer PCB-tBU-S-S-PDI. Hydrogen nuclear magnetic resonance (¹H NMR) and Fourier transform infrared spectroscopy (FTIR) spectra were applied to study the structure of PCB-tBU-S-S-PDI. The cargo-free NPs were administrated to Sprague-Dawley (SD) rats by intraperitoneal injection every 3 days for 30 days. Then, the blood routine examination, blood biochemistry, and histologic slides of rat's organs were carried out to monitor the in vivo biosecurity of cargo-free PCB-tBU-S-S-PDI NPs. ¹H NMR and FTIR spectra confirmed the successfully synthesis of PCB-tBU-S-S-PDI. The cargo-free NPs showed spherical morphology with an average of 139.8 ± 0.26 nm. The results of blood biochemistry and blood routine examination suggested that the cargo-free PCB-tBU-S-S-PDI NPs did not show any influence on the liver and renal functions of treated rats. Significantly, the physiological slides of treated rat's organs did not show any physiological and pathological changes. These phenomena suggested that the PCB-tBU-S-S-PDI NPs had good biosecurity, and it could be used as a vehicle for antineoplastic drug delivery.

Size, shape, charge and "stealthy" surface: Carrier properties affect the drug circulation time in vivo

The present review sets out to discuss recent developments of the effects and mechanisms of carrier properties on their circulation time. For most drugs, sufficient in vivo circulation time is the basis of high bioavailability. Drug carrier plays an irreplaceable role in helping drug avoid being quickly recognized and cleared by mononuclear phagocyte system, to give drug enough time to arrive at targeted organ and tissue to play its therapeutic effect. The physical and chemical properties of drug carriers, such as size, shape, surface charge and surface modification, would affect their in vivo circulation time, metabolic behavior and biodistribution. The final circulation time of carriers is determined by the balance between macrophage recognitions, blood vessel penetration and urine excretion. Therefore, when designing the drug delivery system, we should pay much attention to the properties of drug carriers to get enough in vivo circulation time to arrive at target site eventually. This article mainly reviews the effect of carrier size, size, surface charge and surface properties on its circulation time in vivo, and discusses the mechanism of these properties affecting circulation time. This review has reference significance for the research of long-circulation drug delivery system.

Novel formulation development from Ophiocordyceps sinensis (Berk.) for management of high-altitude maladies

Ophiocordyceps sinensis (Berk.) is a fungus closely related to medicinal mushroom, which belongs to the family Ophiocordycipitaceae. It is a well-known and rich herbal source of bioactive active constituents. The medicinal mushroom has garnered worldwide attention owing to its multifarious bioactivities. This mushroom grows on the larva of ghost moths (Hepialidae) and produces fruiting bodies, which serve as a vital natural source of medicine and supplementary diets. On account of the diverse pharmacological and bioactive constituents present in O. sinensis, it has been established as a potential antioxidant, anticancer, antibacterial, anti-proliferative, anti-inflammatory agent that has been successfully used for treating several health issues, including hypoxia-related problems encountered by mountaineers, pilgrims, tourists and soldiers occurring at high-altitude regions such as acute mountain sickness (AMS), high-altitude pulmonary edema (HAPE), high-altitude cerebral edema (HACE), frostbite, chilblains, hypothermia, etc. The most important pharmacologically active compounds present in the O. sinensis include nucleobases and its derivatives (adenosine, cordycepin, 3-deoxyadenosine, AMP, GMP, UMP, guanosine, uridine), polysaccharides (mannose, glucose, galactose, rhamnose, arabinose, xylose, galactose), proteins, peptides and steroids. This article focuses on the various research endeavors undertaken to scientifically establish the medicinal properties of O. sinensis, highlighting the various principally active compounds, their pharmacological action, drug designing and development and future perspective for various health benefits.

Synthesis of Hemoglobin-Based Oxygen Carrier Nanoparticles By Desolvation Precipitation

Hemoglobin (Hb)-based oxygen carriers (HBOCs) present an alternative to red blood cells (RBCs) when blood is not available. However, the most widely used synthesis techniques have fundamental flaws, which may have contributed toward disappointing clinical application. Polymerized Hb contains a heterogeneous distribution of particle size and shape, while Hb encapsulation inside liposomes results in high lipid burden and low Hb content. Meanwhile, there are a variety of other nanoparticle synthetic techniques which, having found success as drug delivery vehicles, may be well suited to function as an HBOC. We synthesized desolvated Hb nanoparticles (Hb-dNPs) with diameters of approximately 250 nm by the controlled precipitation of Hb with ethanol. Oxidized dextran was found to be an effective surface stabilizing agent that maintained particle integrity. In vitro biophysical characterization showed a high-affinity oxygen delivery profile (P₅₀ = 7.72 mm Hg), suggesting a potential for therapeutic use and opening a new avenue for HBOC research.

Size-Dependent Phagocytic Uptake and Immunogenicity of Gliadin Nanoparticles

The main objective of the present study was to investigate the hemo and immune compatibility of gliadin nanoparticles as a function of particle size. Gliadin nanoparticles of different size were prepared using a modified antisolvent nanoprecipitation method. The hemolytic potential of gliadin nanoparticles was evaluated using in vitro hemolysis assay. Phagocytic uptake of gliadin nanoparticles was studied using rat polymorphonuclear (PMN) leukocytes and murine alveolar peritoneal macrophage (J774) cells. In vivo immunogenicity of gliadin nanoparticles was studied following subcutaneous administration in mice. Gliadin nanoparticles were non-hemolytic irrespective of particle size and hence compatible with blood components. In comparison to positive control zymosan, gliadin nanoparticles with a size greater than 406 ± 11 nm showed higher phagocytic uptake in PMN cells, while the uptake was minimal with smaller nanoparticles (127 ± 8 nm). Similar uptake of gliadin nanoparticles was observed in murine alveolar peritoneal macrophages. Anti-gliadin IgG antibody titers subsequent to primary and secondary immunization of gliadin nanoparticles in mice were in the increasing order of 406 ± 11 nm < 848 ± 20 nm < coarse suspension). On the other hand, gliadin nanoparticles of 127 ± 8 nm in size did not elicit immunogenic response. Phagocytosis and immunogenicity of gliadin nanoparticles are strongly influenced by particle size. The results of this study can provide useful information for rational design of protein-based nanomaterials in drug delivery applications.

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

Superparamagnetic iron oxide nanoparticles (SPIONs) have unique properties with regard to biological and medical applications. SPIONs have been used in clinical settings although their safety of use remains unclear due to the great differences in their structure and in intra- and inter-patient absorption and response. This review addresses potential applications of SPIONs in vitro (formulations), ex vivo (in biological cells and tissues) and in vivo (preclinical animal models), as well as potential biomedical applications in the context of drug targeting, disease treatment and therapeutic efficacy, and safety studies.

Crossing the Blood-Brain Barrier: A Review on Drug Delivery Strategies for Treatment of the Central Nervous System Diseases

Many drugs have been designed to treat diseases of the central nervous system (CNS), especially neurodegenerative diseases. However, the presence of tight junctions at the blood-brain barrier has often compromised the efficiency of drug delivery to target sites in the brain. The principles of drug delivery systems across the blood-brain barrier are dependent on substrate-specific (i.e. protein transport and transcytosis) and non-specific (i.e. transcellular and paracellular) transport pathways, which are crucial factors in attempts to design efficient drug delivery strategies. This review describes how the blood-brain barrier presents the main challenge in delivering drugs to treat brain diseases and discusses the advantages and disadvantages of ongoing neurotherapeutic delivery strategies in overcoming this limitation. In addition, we discuss the application of colloidal carrier systems, particularly nanoparticles, as potential tools for therapy for the CNS diseases.

Selective eradication of human non-small cell lung cancer cells using aptamer-decorated nanoparticles harboring a cytotoxic drug cargo

Targeted cancer therapy is currently the leading modality to enhance treatment selectivity and efficacy, as well as to minimize untoward toxicity to healthy tissues. Herein, we devised and studied nanoparticles (NPs) composed of the biocompatible block-copolymer PEG-PCL entrapping the hydrophobic chemotherapeutic drug paclitaxel (PTX), which are targeted to human non-small cell lung cancer (NSCLC) cells. To achieve selective NSCLC targeting, these NPs were decorated with single-stranded oligonucleotide-based S15 aptamers (S15-APTs), which we have recently shown to serve as efficient tumor cell targeting ligands. Prepared without using surfactants, these 15 nm PEG-PCL/PTX NPs entered NSCLC cells via clathrin-mediated endocytosis. These NPs demonstrated efficient encapsulation of PTX, high selectivity to- and potent eradication of human A549 NSCLC cells, with a remarkable half maximal inhibitory concentration (IC₅₀) of 0.03 μM PTX. In contrast, very high IC₅₀ values of 1.7, 4.2, 43, 87, and 980 µM PTX were obtained towards normal human bronchial epithelial BEAS2B, cervical carcinoma HeLa, colon adenocarcinoma CaCo-2, neonatal foreskin fibroblast FSE, and human embryonic kidney HEK-293 cells, respectively. These results demonstrate 2–5 orders of magnitude difference in the selective cytotoxicity towards NSCLCs, reflecting a potentially outstanding therapeutic window. Moreover, the dual utility of aptamer-decorated NPs for both drug stabilization and selective tumor targeting was studied by increasing APT concentrations during NP “decoration”. The optimal aptamer density on the surface of NPs for selective targeting, for high fluorescence diagnostic signal and for maintaining small particle size to enable endocytosis, was achieved by using 30 nM APTs during NP decoration. Collectively, our findings suggest that these APT-decorated NPs hold great preclinical promise in selective targeting and eradication of human NSCLC cells without harming normal tissues.

Tunable Composition of Dynamic Non-Viral Vectors over the DNA Polyplex Formation and Nucleic Acid Transfection

Polyethylene glycol (PEG) functionalization of non-viral vectors represents a powerful tool through the formation of an overall surface charge shielding ability, which is fundamental for efficient nucleic acid delivery systems. The degree of non-viral vector PEGylation and the molecular weight of utilized PEG is crucial since the excessive use of PEG units may lead to a considerable reduction of the DNA-binding capacity and, subsequently, in a reduction of in vitro transfection efficiency. Herein, we report a detailed study on a series of dynamic combinatorial frameworks (DCFs) containing PEGylated squalene, poly-(ethyleneglycol)-bis(3-aminopropyl) of different lengths, and branched low molecular weight polyethylenimine components, reversibly connected in hyperbranched structures, as efficient dynamic non-viral vectors. The obtained frameworks were capable of forming distinct supramolecular amphiphilic architectures, shown by transmission electron microscopy (TEM) and dynamic light scattering (DLS), with sizes and stability depending on the length of PEG units. The interaction of PEGylated DCFs with nucleic acids was investigated by agarose gel retardation assay and atomic force microscopy (AFM), while their transfection efficiency (using pCS2+MT-Luc DNA as a reporter gene) and cytotoxicity were evaluated in HeLa cells. In addition, the data on the influence of the poly-(ethyleneglycol)-bis(3-aminopropyl) length in composition of designed frameworks over transfection efficiency and tolerance in human cells were analyzed and compared.

SPIONs Prepared in Air through Improved Synthesis Methodology: The Influence of γ-Fe2O3/Fe3O4 Ratio and Coating Composition on Magnetic Properties

Superparamagnetic iron oxide nanoparticles (SPIONs) have shown great potential in biomedicine due to their high intrinsic magnetization behaviour. These are small particles of magnetite or maghemite, and when coated, their surface oxidation is prevented, their aggregation tendency is reduced, their dispersity is improved, and the stability and blood circulation time are increased, which are mandatory requirements in biomedical applications. In this work, SPIONs were synthesized in air through a reduction-precipitation method and coated with four different polymers (Polyethylene glycol(PEG) 1000/6000 and dextran T10/T70). All the synthesized samples were structurally and magnetically characterized by transmission electron microscopy, Fourier transform infra-red spectroscopy, X-ray powder diffraction, Mössbauer spectroscopy, and Superconducting Quantum Interference Device (SQUID) magnetometry. SPIONs centrifuged and dried in vacuum with an average diameter of at least 7.5 nm and a composition ≤60% of maghemite and ≥40% of magnetite showed the best magnetization results, namely a saturation magnetization of ~64 emu/g at 300 K, similar to the best reported values for SPIONs prepared in controlled atmosphere. As far as SPIONs’ coatings are concerned, during their preparation procedure, surface polymers must be introduced after the SPIONs’ precipitation. Furthermore, polymers with shorter chains do not affect the SPIONs’ magnetization performance, although longer chain polymers significantly decrease the coated particle magnetization values, which is undesirable.

Developing Body-Components-Based Theranostic Nanoparticles for Targeting Ovarian Cancer

Ovarian cancer mortality is the highest among gynecologic malignancies. Hence, the major challenges are early diagnosis and efficient targeted therapy. Herein, we devised model theranostic nanoparticles (NPs) for combined diagnostics and delivery of chemotherapeutics, targeted to ovarian cancer cells. These NPs were made of natural biocompatible and biodegradable body components: hyaluronic acid (HA) and serum albumin (SA). The hydrophilic HA served as the targeting ligand for cancer cells overexpressing CD44, the HA receptor. SA, the natural carrier of various ligands through the blood, served as the hydrophobic block of the self-assembling block copolymeric Maillard-conjugates. We show the successful construction of fluorescently-labeled SA-HA conjugate-based theranostic NPs, their loading with paclitaxel (PTX) (association constant (8.6 ± 0.8) × 103 M-1, maximal loading capacity of 4:1 PTX:BSA, and 96% encapsulation efficiency), selective internalization and cytotoxicity to CD44-overexpressing ovarian cancer cells (IC50: 26.4 ± 2.3 nM, compared to 115.0 ± 17.4 of free PTX, and to 58.6 ± 19.7 nM for CD44-lacking cognate ovarian cancer cells). Fluorescein isothiocyanate (FITC) was used for in vitro imaging, whereas long wavelength fluorophores or other suitable tracers would be used for future in vivo diagnostic imaging. Collectively, our findings demonstrate that fluorescent HA-SA NPs harboring a cytotoxic drug cargo can specifically target, label CD44-expressing ovarian cancer cells and efficiently eradicate them.

Anticancer Activity of Chitosan, Chitosan Derivatives, and Their Mechanism of Action

Tailoring of chitosan through the involvement of its amino, acetamido, and hydroxy groups can give derivatives of enhanced solubility and remarkable anticancer activity. The general mechanism of such activity is associated with the disturbances in normal functioning of cell cycle, interference to the central dogma of biological system from DNA to RNA to protein or enzymatic synthesis, and the disruption of hormonal path to biosynthesis to inhibit the growth of cancer cells. Both chitosan and its various derivatives have been reported to selectively permeate through the cancer cell membranes and show anticancer activity through the cellular enzymatic, antiangiogenic, immunoenhancing, antioxidant defense mechanism, and apoptotic pathways. They get sequestered from noncancer cells and provide their enhanced bioavailability in cancer cells in a sustained release manner. This review presents the putative mechanisms of anticancer activity of chitosan and mechanistic approaches of structure activity relation upon the modification of chitosan through functionalization, complex formation, and graft copolymerization to give different derivatives.

Drug conjugates-an emerging approach to treat breast cancer

Breast cancer treatment using a single drug is associated with a high failure rate due, in part, to the heterogeneity of drug response within individuals, nonspecific target action, drug toxicity, and/or development of resistance. Use of dual-drug therapies, including drug conjugates, may help overcome some of these roadblocks by more selective targeting of the cancer cell and by acting at multiple drug targets rather than one. Drug-conjugate approaches include linking drugs to antibodies (antibody-drug conjugates), radionuclides (radioimmunoconjugates), nanoparticles (nanoparticle-drug conjugates), or to other drugs (drug-drug conjugates). Although all of these conjugates might be designed as effective treatments against breast cancer, the focus of this review will be on drug-drug conjugates because of the increase in versatility of these types of drugs with respect to mode of action at the level of the cancer cell either by creating a novel pharmacophore or by increasing the potency and/or efficacy of the drugs' effects at their respective molecular targets. The development, synthesis, and pharmacological characteristics of drug-drug conjugates will be discussed in the context of breast cancer with the hope of enhancing drug efficacy and reducing toxicities to improve patient quality of life.

Physical characterization and in vivo organ distribution of coated iron oxide nanoparticles

Citrate-stabilized iron oxide magnetic nanoparticles (MNPs) were coated with one of carboxymethyl dextran (CM-dextran), polyethylene glycol-polyethylene imine (PEG-PEI), methoxy-PEG-phosphate+rutin, or dextran. They were characterized for size, zeta potential, hysteresis heating in an alternating magnetic field, dynamic magnetic susceptibility, and examined for their distribution in mouse organs following intravenous delivery. Except for PEG-PEI-coated nanoparticles, all coated nanoparticles had a negative zeta potential at physiological pH. Nanoparticle sizing by dynamic light scattering revealed an increased nanoparticle hydrodynamic diameter upon coating. Magnetic hysteresis heating changed little with coating; however, the larger particles demonstrated significant shifts of the peak of complex magnetic susceptibility to lower frequency. 48 hours following intravenous injection of nanoparticles, mice were sacrificed and tissues were collected to measure iron concentration. Iron deposition from nanoparticles possessing a negative surface potential was observed to have highest accumulation in livers and spleens. In contrast, iron deposition from positively charged PEG-PEI-coated nanoparticles was observed to have highest concentration in lungs. These preliminary results suggest a complex interplay between nanoparticle size and charge determines organ distribution of systemically-delivered iron oxide magnetic nanoparticles.

Fucoidan Prolongs the Circulation Time of Dextran-Coated Iron Oxide Nanoparticles

The magnetic properties and safety of dextran-coated superparamagnetic iron oxide nanoparticles (SPIONs) have facilitated their clinical use as MRI contrast agents and stimulated research on applications for SPIONs in particle imaging and magnetic hyperthermia. The wider clinical potential of SPIONs, however, has been limited by their rapid removal from circulation via the reticuloendothelial system (RES). We explored the possibility of extending SPION circulatory time using fucoidan, a seaweed-derived food supplement, to inhibit RES uptake. The effects of fucoidan on SPION biodistribution were evaluated using ferucarbotran, which in its pharmaceutical formulation (Resovist) targets the RES. Ferucarbotran was radiolabeled at the iron oxide core with technetium-99m (99mTc; t1/2 = 6 h) or zirconium-89 (89Zr; t1/2 = 3.3 days). Results obtained with 99mTc-ferucarbotran demonstrated that administration of fucoidan led to a 4-fold increase in the circulatory half-life (t1/2 slow) from 37.4 to 150 min (n = 4; P < 0.0001). To investigate whether a longer circulatory half-life could lead to concomitant increased tumor uptake, the effects of fucoidan were tested with 89Zr-ferucarbotran in mice bearing syngeneic subcutaneous (GL261) tumors. In this model, the longer circulatory half-life achieved with fucoidan was associated with a doubling in tumor SPION uptake (n = 5; P < 0.001). Fucoidan was also effective in significantly increasing the circulatory half-life of perimag-COOH, a commercially available SPION with a larger hydrodynamic size (130 nm) than ferucarbotran (65 nm). These findings indicate successful diversion of SPIONs away from the hepatic RES and show realistic potential for future clinical applications.

Magnetic Nano-Systems in Drug Delivery and Biomedical Applications

Nanotechnology is that sphere of technology that involves the participation of biology, chemistry, physics, and engineering sciences. Nanoscale science defines the chemistry and physics of structures lying in the range of 1-100 nm. Among the nanosystems researched, magnetic nanosystems are highlighted due their unique ability, which enables their targeting to specific locations on application of an external magnetic field. The exhibited property of these magnetic nanosystems being super-paramagnetism, there is no retention of magnetic property on removal of the magnetic field, thus enabling a reversion of the targeting process. For effective utilization of these nanosystems, they should be reduced to nanosizes, layered with biocompatible entities, stabilized, and functionalized. In the chapter, synthesis and functionalization and stabilization are elucidated. The biomedical applications such as targeted delivery, MRI, magnetic hyperthermia, tissue engineering, gene delivery, magnetic immunotherapy, magnetic detoxification, and nanomagnetic actuation are discussed.

Establishment of a biophysical model to optimize endoscopic targeting of magnetic nanoparticles for cancer treatment

Superparamagnetic iron oxide nanoparticles (SPION) may be used for local tumor treatment by coupling them to a drug and accumulating them locally with magnetic field traps, that is, a combination of permanent magnets and coils. Thereafter, an alternating magnetic field generates heat which may be used to release the thermosensitively bound drug and for hyperthermia. Until today, only superficial tumors can be treated with this method. Our aim was to transfer this method into an endoscopic setting to also reach the majority of tumors located inside the body. To find the ideal endoscopic magnetic field trap, which accumulates the most SPION, we first developed a biophysical model considering anatomical as well as physical conditions. Entities of choice were esophageal and prostate cancer. The magnetic susceptibilities of different porcine and rat tissues were measured with a superconducting quantum interference device. All tissues showed diamagnetic behavior. The evaluation of clinical data (computed tomography scan, endosonography, surgical reports, pathological evaluation) of patients gave insight into the topographical relationship between the tumor and its surroundings. Both were used to establish the biophysical model of the tumors and their surroundings, closely mirroring the clinical situation, in which we could virtually design, place and evaluate different electromagnetic coil configurations to find optimized magnetic field traps for each tumor entity. By simulation, we could show that the efficiency of the magnetic field traps can be enhanced by 38-fold for prostate and 8-fold for esophageal cancer. Therefore, our approach of endoscopic targeting is an improvement of the magnetic drug-targeting setups for SPION tumor therapy as it holds the possibility of reaching tumors inside the body in a minimal-invasive way. Future animal experiments must prove these findings in vivo.

Enhanced anti-metastatic and anti-tumorigenic efficacy of Berbamine loaded lipid nanoparticles in vivo

Research on metastasis is gaining momentum for effective cancer management. Berbamine (BBM) has the potency to act as a therapeutic in multiple cancers and cancer metastasis. However, the major limitation of the compound includes poor bioavailability at the tumor site due to short plasma half-life. Here, our major objective involved development of lipid based nanoparticles (NPs) loaded with BBM with an aim to circumvent the above problem. Moreover its, therapeutic potentiality was evaluated through various in vitro cellular studies and in vivo melanoma primary and experimental lung metastatic tumor model in C57BL/6 mice. Results of different cellular experiments demonstrated enhanced therapeutic efficacy of BBM-NPs in inhibiting metastasis, cell proliferation and growth as compared to native BBM in highly metastatic cancer cell lines. Further, in vivo results demonstrated suppression of primary B16F10 melanoma tumor growth in C57BL/6 mice model treated with BBM-NPs than that of native BBM. Importantly, a moderately cytotoxic dose of BBM-NPs was able to significantly suppress the incidence of B16F10 cells lung metastasis in vivo. Results indicated development of an effective approach for aggressive metastatic cancer.

A Zwitterionic-Shielded Carrier with pH-Modulated Reversible Self-Assembly for Gene Transfection

Cationic vectors are ideal candidates for gene delivery thanks to their capability to carry large gene inserts and their scalable production. However, their cationic density gives rise to high cytotoxicity. We present the proper designed core-shell polyplexes made of either poly(ethylene imine) (PEI) or poly(2-dimethylamino ethyl methacrylate) (PDMAEMA) as the core and zwitterionic poly(acrylic acid)-block-poly(sulfobetaine methacrylate) (PAA-b-PSBMA) diblock copolymer as the shell. Gel retardation and ethidium bromide displacement assays were used to determine the PEI/DNA or PDMAEMA/DNA complexation. At neutral pH, the copolymer serves as a protective shell of the complex. As PSBMA is a nonfouling block, the shell reduced the cytotoxicity and enhanced the hemocompatibility (lower hemolysis activity, longer plasma clotting time) of the gene carriers. PAA segments in the copolymer impart pH sensitivity by allowing deshielding of the core in acidic solution. Therefore, the transfection efficiency of polyplexes at pH 6.5 was better than at pH 7.0, from β-galactosidase assay, and for all PAA-b-PSBMA tested. These results were supported by more favorable physicochemical properties in acidic solution (zeta potential, particle size, and interactions between the polymer and DNA). Thus, the results of this study offer a potential route to the development of efficient and nontoxic pH-sensitive gene carriers.

Development and characterisation of disulfiram-loaded PLGA nanoparticles for the treatment of non-small cell lung cancer

Non-Small Cell Lung Cancer (NSCLC) is the most common type of lung cancer in both men and women. A recent phase IIb study demonstrated that disulfiram (DSF) in combination with cisplatin and vinorelbine was well tolerated and prolonged the survival of patients with newly diagnosed NSCLC. However, DSF is rapidly (4min) metabolised in the bloodstream and it is this issue which is limiting its anticancer application in the clinic. We have recently demonstrated that a low dose of DSF-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles supplemented with oral Cu inhibited tumour growth and reduced metastasis in a xenograft mouse lung cancer model. Here we demonstrate the influence of PLGA polymer, stabilizer loading and molecular weight as well as sonication time on the characteristics, including DSF release and the cytotoxicity of 10% w/w DSF-loaded PLGA nanoparticles. The paper demonstrates that the choice of PLGA as no significance on the characteristics of the nanoparticles apart from their DSF release, which is due to the differing degradation rates of the polymers. However, increasing the loading and molecular weight of the stabilizer as well as the sonication time reduced the size of the nanoparticles, reduced their ability to protect the DSF from reacting with Cu and degrading in serum, while increasing their DSF release rate and cytotoxicity. Additionally, increasing the sonication time resulted in the premature degradation of the PLGA, which increased the permeability of the nanoparticles further decreasing their ability to protect DSF from reacting with Cu and degrading in serum, while increasing their DSF release rate and cytotoxicity.

Ligand-based targeted therapy: a novel strategy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with high morbidity and mortality worldwide. Chemotherapy is recommended to patients with intermediate or advanced stage cancer. However, the conventional chemotherapy yields low desired response rates due to multidrug resistance, fast clearance rate, nonspecific delivery, severe side effects, low drug concentration in cancer cells, and so on. Nanoparticle-mediated targeted drug delivery system can surmount the aforementioned obstacles through enhanced permeability and retention effect and active targeting as a novel approach of therapeutics for HCC in recent years. The active targeting is triggered by ligands on the delivery system, which recognize with and internalize into hepatoma cells with high specificity and efficiency. This review focuses on the latest targeted delivery systems for HCC and summarizes the ligands that can enhance the capacity of active targeting, to provide some insight into future research in nanomedicine for HCC.

A novel blood-pooling MR contrast agent: Carboxymethyl-diethylaminoethyl dextran magnetite

Gadofosveset trisodium is available as a prolonged pooling vascular contrast agent for magnetic resonance imaging. As gadolinium (Gd)-based agents may increase the risk for nephrogenic systemic fibrosis in patients with severe renal insufficiency, the present study synthesized carboxymethyl-diethylaminoethyl dextran magnetite (CMEADM) particles as a blood-pooling, non-Gd‑based contrast agent. CMEADM particles carry a negative or positive charge due to the binding of amino and carboxyl groups to the hydroxyl group of dextran. The present study evaluated whether the degree of charge alters the blood‑pooling time. The evaluation was performed by injecting four groups of three Japanese white rabbits each with CMEADM‑, CMEADM2‑, CMEADM+ (surface charges: ‑10.4, ‑41.0 and +9.6 mV, respectively) or with ultrasmall superparamagnetic iron oxide (USPIO; ‑11.5 mV). The relative signal intensity (SIrel) of each was calculated using the following formula: SIrel = (SI post‑contrast ‑ SI pre‑contrast / SI pre‑contrast) x 100. Following injection with the CMEADMs, but not with USPIO, the in vivo pooling time was prolonged to >300 min. No significant differences were attributable to the electric charge among the CMEADM‑, CMEADM2‑ or and CMEADM+ particles when analyzed with analysis of variance and Tukey's HSD test. Taken together, all three differently‑charged CMEADM2 particles exhibited prolonged vascular enhancing effects, compared with the USPIO. The degree of charge of the contrast agents used in the present study did not result in alteration of the prolonged blood pooling time.

Antitumor and Antimetastasis Activities of Heparin-based Micelle Served As Both Carrier and Drug

Effective treatments for tumors are not easy to achieve due to the existence of metastases, which are responsible for most tumor death. Hence, a new drug delivery system is a pressing need, which should be biocompatible, stimuli-responsive, and multifunctional, including antitumor, antimetastasis, and antiangiogenesis effects. However, it is challenging to achieve all of these properties in one drug delivery system. Here, we developed a system of drug DOX and heparin into one self-assemble nanoparticle via pH-sensitive hydrazone bond and hydrophobic groups, deoxycholate. In the process, heparin itself was not only as the hydrophilic segments of the carrier, but also processed multiple biological functions such as antiangiogenesis and antimetastasis effect. The micelle nanoparticle HD-DOX processed good stability and acidic pH-triggered drug release property. After systemic administration, heparin-based micelle nanoparticle showed longer half-time and enhanced accumulation of DOX in tumors through the enhanced permeability and retention effect, leading to more efficient antitumor effects. In addition, heparin could hinder platelet-induced tumor cells epithelial-mesenchymal transition (EMT) and partially affect cell actin cytoskeletal arrangement, resulting in the disorganization of the actin cytoskeleton. Therefore, HD-DOX exhibited significant inhibitory effect on the metastasis in melanoma animal model in C57BL/6 mouse. Meanwhile, benefited from the antiangiogenesis effect of heparin, tube formations in endothelial cells were effectively inhibited and tumor vascular density was decreased by HD-DOX. Taken together, our study developed a self-assembly nanoplatform that both the drug and carrier had therapeutic effects with ideal antitumor efficacy.

Polymeric protective agents for nanoparticles in drug delivery and targeting

Surface modification/functionalization of nanoparticles (NPs) using polymeric protective agents is an issue of great importance and actuality for drug delivery and targeting. Improving the blood circulation half-life of surface-protected nanocarriers is closely related to the elimination of main biological barriers and limiting factors (protein absorption and opsonization), due to the phagocytic activity of reticuloendothelial system. For passive or active targeted delivery, in biomedical area, surface-functionalized NPs with tissue-recognition ligands were designed and optimized as a result of modern research techniques. Also, multi-functionalized nanostructures are characterized by enhanced bioavailability, efficacy, targeted localization, active cellular uptake, and low side effects. Surface-protected NPs are obtained from biocompatible, biodegradable and less toxic natural polymers (dextran, β-cyclodextrin, chitosan, hyaluronic acid, heparin, gelatin) or synthetic polymers, such as poly(lactic acid), poly(lactic-co-glycolic) acid, poly(ε-caprolactone) and poly(alkyl cyanoacrylates). PEGylation is one of the most important functionalization methods providing steric stabilization, long circulating and 'stealth' properties for both polymeric and inorganic-based nanosystems. In addition, for their antimicrobial, antiviral and antitumor effects, cutting-edge researches in the field of pharmaceutical nanobiotechnology highlighted the importance of noble metal (platinum, gold, silver) NPs decorated with biopolymers.

A new method of wound treatment: targeted therapy of skin wounds with reactive oxygen species-responsive nanoparticles containing SDF-1α

Objective

To accelerate wound healing through promoting vascularization by using reactive oxygen species (ROS)-responsive nanoparticles loaded with stromal cell-derived factor-1α(SDF-1α).

Methods

The ROS-reactive nanomaterial poly-(1,4-phenyleneacetone dimethylene thioketal) was synthesized, and its physical and chemical properties were characterized. ROS-responsive nanoparticles containing SDF-1α were prepared through a multiple emulsion solvent evaporation method. The loading capacity, stability, activity of the encapsulated protein, toxicity, and in vivo distribution of these nanoparticles were determined. These nanoparticles were administered by intravenous infusion to mice with full-thickness skin defects to study their effects on the directed chemotaxis of bone marrow mesenchymal stem cells, wound vascularization, and wound healing.

Results

The synthesized ROS-reactive organic polymer poly-(1,4-phenyleneacetone dimethylene thioketal) possessed a molecular weight of approximately 11.5 kDa with a dispersity of 1.97. ROS-responsive nanoparticles containing SDF-1α were prepared with an average diameter of 110 nm and a drug loading capacity of 1.8%. The encapsulation process showed minimal effects on the activity of SDF-1α, and it could be effectively released from the nanoparticles in the presence of ROS. Encapsulated SDF-1α could exist for a long time in blood. In mice with full-thickness skin defects, SDF-1α was effectively released and targeted to the wounds, thus promoting the chemotaxis of bone marrow mesenchymal stem cells toward the wound and its periphery, inducing wound vascularization, and accelerating wound healing.

Iron Oxide as an MRI Contrast Agent for Cell Tracking

Iron oxide contrast agents have been combined with magnetic resonance imaging for cell tracking. In this review, we discuss coating properties and provide an overview of ex vivo and in vivo labeling of different cell types, including stem cells, red blood cells, and monocytes/macrophages. Furthermore, we provide examples of applications of cell tracking with iron contrast agents in stroke, multiple sclerosis, cancer, arteriovenous malformations, and aortic and cerebral aneurysms. Attempts at quantifying iron oxide concentrations and other vascular properties are examined. We advise on designing studies using iron contrast agents including methods for validation.