Targeted Drug Delivery Agents Research Articles

Biomass-derived carbon dots as fluorescent quantum probes to visualize and modulate inflammation

Quantum dots, which won the Nobel Prize in Chemistry, have recently gained significant attention in precision medicine due to their unique properties, such as size-tunable emission, high photostability, efficient light absorption, and vibrant luminescence. Consequently, there is a growing demand to identify new types of quantum dots from various sources and explore their potential applications as stimuli-responsive biosensors, biomolecular imaging probes, and targeted drug delivery agents. Biomass-waste-derived carbon quantum dots (CQDs) are an attractive alternative to conventional QDs, which often require expensive and toxic precursors, as they offer several merits in eco-friendly synthesis, preparation from renewable sources, and cost-effective production. In this study, we evaluated three CQDs derived from biomass waste for their potential application as non-toxic bioimaging agents in various cell lines, including human dermal fibroblasts, HeLa, cardiomyocytes, induced pluripotent stem cells, and an in-vivo medaka fish (Oryzias latipes) model. Confocal microscopic studies revealed that CQDs could assist in visualizing inflammatory processes in the cells, as they were taken up more by cells treated with tumor necrosis factor-α than untreated cells. In addition, our quantitative real-time PCR gene expression analysis has revealed that citric acid-based CQDs can potentially reduce inflammatory markers such as Interleukin-6. Our studies suggest that CQDs have potential as theragnostic agents, which can simultaneously identify and modulate inflammatory markers and may lead to targeted therapy for immune system-associated diseases.

Nanobiopolymers in cancer therapeutics: advancing targeted drug delivery through sustainable and controlled release mechanisms.

Nanobiopolymers have emerged as a transformative frontier in cancer treatment, leveraging nanotechnology to transform drug delivery. This review provides a comprehensive exploration of the multifaceted landscape of nano-based biopolymers, emphasizing their diverse sources, synthesis methods, and classifications. Natural, synthetic, and microbial nanobiopolymers are scrutinized, along with elucidation of their underlying mechanisms and impact on cancer drug delivery; the latest findings on their deployment as targeted drug delivery agents for cancer treatment are discussed. A detailed analysis of nanobiopolymer sources, including polysaccharides, peptides, and nucleic acids, highlights critical attributes like biodegradability, renewability, and sustainability essential for therapeutic applications. The classification of nanobiopolymers based on their origin and differentiation among natural, synthetic, and microbial sources are thoroughly examined for inherent advantages, challenges, and suitability for cancer therapeutics. The importance of targeted drug release at tumour sites, crucial for minimizing adverse effects on normal tissues, is discussed, encompassing various mechanisms. The role of polymer membrane coatings as a pivotal barrier for facilitating controlled drug release through diffusion is elucidated, providing further insight into efficient methods for cancer treatment and thus consolidating the current knowledge base for researchers and practitioners in the field of nanobiopolymers and cancer therapeutics.

Curcumin-loaded porous particles functionalized with pH-responsive cell-penetrating peptide for colorectal cancer targeted drug delivery.

The anticancer properties of curcumin have been broadly examined in several shapes, such as nanoparticles and nanocomposite structures. Despite its benefits, curcumin also has some disadvantages, including rapid metabolism, poor absorption, and rapid systemic excretion. Therefore, numerous strategies have been used to increase curcumin's bioavailability. One of these approaches is the use of porous particles like aerogels as drug carriers. Aerogels are special due to their peculiar physical structure. They have a high specific surface area, a significant amount of porosity, and a solid composition, which make them a good choice for drug delivery systems. In the present study, a pH-sensitive aerogel was constructed and evaluated for targeted drug delivery of curcumin to colon cancer. To control the release of curcumin, trehalose was used as a coating agent, and PLP (poly(l-lysine isophthalamide)) was used as a targeted drug delivery agent. PLP is a pseudo-peptidic polymer that increases the cell permeability. In order to investigate and compare the synthesized aerogel before and after loading curcumin and coating with trehalose, physicochemical characterization analyses were performed. Finally, the efficacy of the final formulation was evaluated on HT29 colon cells using the cell bioavailability test. The results indicated the successful synthesis of the aerogel with porous structure with solitary cavities. The trehalose coating performed well, preventing drug release at lower pH but allowing the drug to be released at its intended site. The designed curcumin-loaded porous particles functionalized with PLP showed significant efficacy due to increasing penetration of curcumin into cells, and has potential for use as a new drug carrier with dual effectivity in cancer therapy.

Mitigation of Benzene-Induced Haematotoxicity in Sprague Dawley Rats through Plant-Extract-Loaded Silica Nanobeads.

Benzene, a potent carcinogen, is known to cause acute myeloid leukaemia. While chemotherapy is commonly used for cancer treatment, its side effects have prompted scientists to explore natural products that can mitigate the haematotoxic effects induced by chemicals. One area of interest is nano-theragnostics, which aims to enhance the therapeutic potential of natural products. This study aimed to enhance the effects of methanolic extracts from Ocimum basilicum, Rosemarinus officinalis, and Thymus vulgaris by loading them onto silica nanobeads (SNBs) for targeted delivery to mitigate the benzene-induced haematotoxic effects. The SNBs, 48 nm in diameter, were prepared using a chemical method and were then loaded with the plant extracts. The plant-extract-loaded SNBs were then coated with carboxymethyl cellulose (CMC). The modified SNBs were characterized using various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-visible spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. The developed plant-extract-loaded and CMC-modified SNBs were administered intravenously to benzene-exposed rats, and haematological and histopathological profiling was conducted. Rats exposed to benzene showed increased liver and spleen weight, which was mitigated by the plant-extract-loaded SNBs. The differential white blood cell (WBC) count was higher in rats with benzene-induced haematotoxicity, but this count decreased significantly in rats treated with plant-extract-loaded SNBs. Additionally, blast cells observed in benzene-exposed rats were not found in rats treated with plant-extract-loaded SNBs. The SNBs facilitated targeted drug delivery of the three selected medicinal herbs at low doses. These results suggest that SNBs have promising potential as targeted drug delivery agents to mitigate haematotoxic effects induced by benzene in rats.

Synthesis and characterization of Drymaria cordata mediated encapsulation of Zeolitic Imidazolate Framework‑8 and their antibacterial action against drugs resistant bacteria

The encapsulation of metal–organic frameworks (MOFs) with bioactive compounds present in plant crude extract is extremely coveted. Novel DC@ZIF-8 nanocomposites are successfully synthesized using a green technique. DC@ZIF-8 nanocomposites are characterized by diverse techniques such as UV, FT-IR, XRD, SEM, TEM, TGA and BET analysis. GCMS analysis of extract confirms the presence of 14 antimicrobial compounds such as Hecanol, Hexadecene, Hexadecanol, Neophytadiene, and Pentadecanone. DC@ZIF-8 nanocomposites revealed outstanding antibacterial efficacy against the cephalosporin-carbapenem resistant Escherichia coli (CCREC), methicillin-resistant Staphylococcus aureus (MRSA), chloramphenicol-resistant Bacillus subtilis (MTCC-441) and β-lactams-resistant Pseudomonas aeruginosa (MTCC-1688) strains. Minimum inhibitory concentration (MIC) has been evaluated for DC@ZIF-8 nanocomposites against four bacterial strains using 96 well microtiter plate dilution methods. DC@ZIF-8 has better electrostatic interaction with the bacterial membrane in comparison to bare ZIF-8 framework and plant extract that results into greater zone of inhibition. Our major findings showed the novel synthesis and encapsulation of antibacterial compounds present in Drymaria cordata extract and enhanced bioefficacy of DC@ZIF-8 nanomaterials against pathogenic bacteria. In conclusion, the DC@ZIF-8 nanocomposite has endless therapeutic potential to act as a targeted drug delivery agent against bacterial disorders.

Superparamagnetic hyperthermia and cytotoxicity properties of bimagnetic core–shell nanoparticles synthesized by solvothermal reflux method

Magnetic properties of spinel ferrites nanoparticles (NPs) were well studied for various applications, including biomedical applications such as magnetic hyperthermia agents, magnetic resonance imaging (MRI) contrast agents, targeted drug delivery agents, etc., Magnetic properties of these nanoparticles were altered by metal cations substitution as well as variation of size and shape of nanoparticles. Here hard–soft magnetic materials based magnetic exchange coupled bimagnetic CoFe2O4-CaFe2O4, and CaFe2O4-CoFe2O4 core–shell nanoparticles (CSNPs) with narrow size distribution were synthesized to alter their magnetic properties. Structural, morphology, magnetic, superparamagnetic hyperthermia (SPHT), and cytotoxicity properties of these NPs were reported. Unimagnetic phase CoFe2O4, CaFe2O4 nanoparticles were also studied for comparison. Though CaFe2O4 macrocrystals crystallizes in orthorhombic structure, CaFe2O4 nanocrystals crystallizes in cubic spinel structure whereas both macro- and nanoparticles of CoFe2O4 crystallizes in spinel structure. Scanning electron nanographs (electrongraphs) of all samples show narrow size distributed spherical particles of average particle size of around 10 nm and is confirmed by transmission electron nanographs. Room temperature magnetic hysteresis loop of all samples were shown superparamagnetic nature with very low coercive field. Bimagnetic CSNPs show higher specific heat generation rate (SHR) or specific magnetic field energy absorption rate (SAR) of superparamagnetic nanoparticles (474 W/g for CaFe2O4-CoFe2O4 CSNPs under H = 35.5 kAm−1 and f = 316 kHz field parameters ) compared to counterpart unimagnetic nanoparticles (407 W/g for CaFe2O4 NPs). However, the SAR decreases with increase of magnetic nanoparticles (MNPs) concentration in the dispersion medium due to reduced superparamagnetic relaxation time resulting from magnetic dipole interactions among dispersed nanoparticles. This is also confirmed in SPHT properties of dispersant removed CSNPs. Cytotoxicity studies show that cell viability increases with MNPs concentration due to increased colorimetric interference of iron oxide and inhomogeneous distribution of MNPs, due to magnetic interactions, among cell culture wells, at higher concentration. These CSNPs may be used for localized SPHT in cancer therapy.

Prospects in the use of gold nanoparticles as cancer theranostics and targeted drug delivery agents

Prospects in the use of gold nanoparticles as cancer theranostics and targeted drug delivery agents

Cavitation dynamics of histotripsy bubble cloud nucleated from echogenic liposomes

Deep vein thrombosis is a serious health concern worldwide. Administration of catheter-directed thrombolytics is the primary approach to achieve vessel patency for critical obstructions. Adjuvant techniques that localize thrombolytic delivery will improve treatment outcomes and reduce the potential caustic bleeding associated with systemic lytic administration. Histotripsy is a bubble-based focused ultrasound therapy that has been shown to act synergistically with lytic to promote clot degradation. Combining histotripsy with a targeted drug delivery agent may further improve treatment efficacy. Echogenic liposomes are vesicles formulated to entrain the thrombolytic, and can be triggered with ultrasound to release drugs locally. The objective of this study was to assess histotripsy bubble cloud dynamics nucleated from echogenic liposomes in an in vitro venous flow model. The change in liposome echogenicity following histotripsy exposure was assessed with high frame rate imaging. Hypoechogenicity indicative of liposome destruction extended beyond the focal region, with a strong decrease in pixel intensity immediately after the applied histotripsy pulse. Interestingly, echogenicity was restored to baseline levels over the course of ∼4 s, which was attributed to vigorous fluid mixing from bubble cloud oscillations. These results indicate an interesting range of bubble cloud behaviors when histotripsy is combined with echogenic liposomes.

Polymer based Drug Delivery Systems- benchtop to Bedside Transition

Research in the field of polymers and polymeric materials has garnered immense attention in the past few decades due to the versatile functional and structural capabilities of polymers which often can be manipulated for applications in the field of therapy and diagnosis for a host of diseases and disorders. Polymer therapeutics comprises polymer-drug and polymer-protein conjugates as well as supramolecular systems used as drug delivery systems. Although the pharmacological industry invests immensely in the design and discovery of novel drug molecules, small molecular drugs are often inefficient in targeting many diseases like deep seated low vasculature tumours, metastasized cancers and various autoimmune diseases. Coupled with a rapid clearance rate, low solubility, drug resistance and high off target toxicity these small molecular drugs often present modest benefits for a host of common diseases. In order to improve the therapeutic index of pre-existing drugs and shortening the translation from preclinical validation to clinical approval, a vast area of drug delivery research focuses on the improvement of drug carriers by various alterations. The major challenges currently faced by drug delivery systems include a low payload, transition through the desmoplastic barrier for solid tumours and high hepatic and renal clearance. In order to address these issues numerous polymer–protein and polymer-drug conjugates have been engineered and have reported to enhance the stability and pharmacokinetic properties of the active drugs. Highly toxic anticancer drugs like doxorubicin, cis-platin and gemcitabine have successfully been coupled with high molecular weight polymers to formulate targeted drug delivery agents, some of which have undergone successful clinical trials. Apart from PEGylated polymers, dendritic polymers and polyplexes with DNA or RNA moieties have also been considered as candidates for improving the therapeutic index of various drugs. Ongoing efforts in the development of polymer-based therapeutics are promising and open new horizons for personalized medicine for effective cure of various life-threatening diseases.

Nano-MOFs as targeted drug delivery agents to combat antibiotic-resistant bacterial infections.

The drug resistance of bacteria is a significant threat to human civilization while the action of antibiotics against drug-resistant bacteria is severely limited owing to the hydrophobic nature of drug molecules, which unquestionably inhibit its permanency for clinical applications. The antibacterial action of nanomaterials offers major modalities to combat drug resistance of bacteria. The current work reports the use of nano–metal-organic frameworks encapsulating drug molecules to enhance its antibacterial activity against model drug-resistant bacteria and biofilm of the bacteria. We have attached rifampicin (RF), a well-documented antituberculosis drug with tremendous pharmacological significance, into the pore surface of zeolitic imidazolate framework 8 (ZIF8) by a simple synthetic procedure. The synthesized ZIF8 has been characterized using the X-ray diffraction (XRD) method before and after drug encapsulation. The electron microscopic strategies such as scanning electron microscope and transmission electron microscope methods were performed to characterize the binding between ZIF8 and RF. We have also performed picosecond-resolved fluorescence spectroscopy to validate the formation of the ZIF8-RF nanohybrids (NHs). The drug release profile experiment demonstrates that ZIF8-RF depicts pH-responsive drug delivery and is ideal for targeting bacterial disease corresponding to its inherent acidic nature. Most remarkably, ZIF8-RF gives enhanced antibacterial activity against methicillin-resistant Staphylococcus aureus bacteria and also prompts entire damage of structurally robust bacterial biofilms. Overall, the present study depicts a detailed physical insight for manufactured antibiotic-encapsulated NHs presenting tremendous antimicrobial activity that can be beneficial for manifold practical applications.

Thermal and microwave synthesized SPIONs: Energy effects on the efficiency of nano drug carriers.

Superparamagnetic iron oxide nanoparticles (SPIONs) were optimally synthesized employing two energy sources viz. thermal and microwave using low temperature co-precipitation process. Both methods yielded particles with optimum physicochemical properties for biomedical applications like smaller size (~6--7nm), narrow size distribution (standard deviation ~1.6-1.7nm) and good magnetic parameters (saturation magnetisation ~53emu/g at 9T). Simplified process made use of domestic oven. After coating by amino acid serine, successful loading (>8wt%) of drug Doxorubicin was achieved for both SPIONs. Microwave sample showed equivalently efficient drug loading despite half the serine coating. Findings were confirmed by various techniques like X-ray diffraction (XRD), transmission electron microscopy (TEM), Vibrating sample magnetometer (VSM) and thermo gravimetric analysis (TGA) etc. Differences in thermal homogeneities and efficiency of heat transfer between two energy modes affected the properties of synthesized SPIONs. Differences were observed in amount of serine coating, drug release behaviour and in vitro experiments on A549 cells like internalisation and cell viability data. About 59 and 39% pH and time dependent drug release at pH5 was obtained for thermal and microwave sample respectively. In vitro experiments confirmed the successful internalisation and cell death, supporting the suitability of SPIONS as efficient targeted drug carriers. Despite lesser drug release, microwave sample showed comparable in vitro results. Study emphasizes the role and importance of energy in affecting the efficiency and functional behaviour of SPIONs as nano drug carriers. Being biocompatible and magnetic these particles can be applied successfully as efficient targeted drug delivery agents.

Dosimetry of Nano-Radio-Ytterbium Therapy by MIRD and MCNP methods for humans’ organs

Introduction: Nano radio-pharmaceutical therapy (NRPT) is a new method for solid tumor therapy. The treatment uses a radioactive form of radionuclide encapsulated in the poly amido amine dendrimers. The poly (amidoamine) (PAMAM) dendrimers have attracted attentions for cancer treatment by their characteristics of targeted drug carriers, delivery agents, and imaging agents in human systems. We have reported the preparation of dendrimer encapsulated ytterbium-175 radio- nanoparticles and its biodistribution in tumor bearing rats.175Yb (T1/2=4.2 days), decays to stable 175Lu with a β- emitter with 470 keV maximum energy (86.5%) and γ photons of 113 keV (1.9%), 282keV (3.1%) and 396 keV (6.5%) that are appropriate for imaging. This paper aims at comparing dosimetric assessments in human performed with Monte Carlo codes and MIRD based on the experimental results of biodistribution of dendrimer encapsulated ytterbium-175.Materials and Methods: All chemical materials including, Ytterbium (III) oxide (Yb2O3), PAMAMG5-NH2 dendrimer in 5% methanol solution and HNO3, Sodium boro- hydride (NaBH4) were purchased from Sigma Aldrich Chemical Co. USA and Merck, Germany. For biodistribution study 20 female Balb/c mice were purchased from Pasteur Institute of Iran. To estimate the absorbed dose by both methods, MCNP and MIRD, the cumulated activity in source organs were calculated by the percentage of injected dose in humans’ organs. The residence times (τ) in the source organs were obtained by integration of respective fit functions, on biokinetics curve, after accounting for the physical decay of the 175Yb. The dose calculation was done for a certain group of organs of human following the MIRD technique. To simulate the problem with MCNP, the ORNL phantom was used. The desired result for this study is absorbed doses of vital organs (liver, spleen, lung and kidney). Results: The maximum uptake of radio-compound are in the liver, lung and spleen. The biodistribution shows the characteristics of nanoparticles such as size and surface hydrophobicity that determine the amount of adsorbed radiopharmaceuticals in organs. The initial fast distribution of radiotracer is throughout liver, lung, and Bone, with slower accumulation in blood and spleen. The result of 2 methods (MIRD versus MCNPX) reveals that MIRD underestimate the absorbed dose for bladder, bone, lung, and ovaries while overestimate for liver, muscle and spleen. In this study the absorbed dose from 175Yb- PAMAM estimated by MCNPX for liver, lung, spleen, kidney and bone are 1.266, 8.081E-01, 8.347E-01, 3.979E-02 and 1.706E-02 mGy/MBq respectively Conclusion: Owing to the stability of PAMAM encapsulated Yb-175 and the size of nano- particle the concentrations are mostly in liver and lungs. State of- the-art dosimetry depends on the duration of the biokinetics of the radiopharmaceutical and a calculation of residence times including an analysis of the errors associated with the respective calculation that aimed in this study. The results showed that this nano-radiopharmaceutical has potential of application for liver and lung tumors.

Fabrication of Amphiphilic Nanoparticles via Mixed Homopolymer Brushes and NMR Characterization of Surface Phase Separation

“Patchy particles”, where the surface is anisotropically patterned through variation in the surface composition, can assemble into different colloidal crystal structures as well as act as interface stabilizers, heterogeneous reaction catalysts, and targeted drug delivery agents. Patchy nanoparticles (NPs) can be formed by adsorbing two chemically different polymer chains that will spontaneously phase separate. Although there is growing interest in polymer-based patchy nanoparticles, the majority of the studies have been theoretical rather than experimental due to difficulties in preparing significant quantities of nanoparticles with controlled polymer ratios. Likewise, characterization of the phase separation on the nanoparticle surface is challenging. Here we simultaneously overcome the synthesis and characterization hurdles by developing a facile, versatile protocol to produce sufficient quantities of patchy NPs for quantitative solid-state NMR measurements of the patch fractions, degree of phase separation, and morphology. Monodisperse 3.5 nm ZrO2 nanocrystals with polystyrene (PS) and poly(ethylene oxide) (PEO) ligands, covering the entire possible composition range, were reproducibly prepared through a simple exchange process. This approach has the advantage of well-defined polymer molecular weights and NP sizes, allowing experimental validation of theoretical predictions for nanophase separation in NPs with mixed homopolymer brushes. Upon exposure to a nonselective solvent, the nanoparticles assemble into different morphologies, namely micelles and vesicles, as a function of the PEO:PS ratios.

Development of sesbania mosaic virus nanoparticles for imaging.

The capsids of viruses have a high degree of symmetry. Therefore, virus nanoparticles (VNPs) can be programmed to display many imaging agents precisely. Plant VNPs are biocompatible, biodegradable and non-infectious to mammals. We have carried out bioconjugation of sesbania mosaic virus (SeMV), a well characterized plant virus, with fluorophores using reactive lysine-N-hydroxysuccinimide ester and cysteine-maleimide chemistries. Monitoring of cellular internalization of labelled SeMV nanoparticles (NPs) by confocal microscopy and flow cytometry showed that the particles have a natural preference for entry into MDA-MB-231 (breast cancer) cells, although they could also enter various other cell lines. The fluorescence of SeMV NPs labelled via the cysteines with Cy5.5 dye was found to be more stable and was detectable with greater sensitivity than that of particles labelled via the lysines with Alexa Fluor. Live-cell imaging using SeMV internally labelled with Cy5.5 showed that it could bind to MDA-MB-231 cells in less than 5 minutes and enter the cells within 15 minutes. The particles undergo endolysosomal degradation by 6 h as evidenced by their co-localization with LAMP-1. Far-western blot analysis with a HeLa cell membrane protein fraction showed that SeMV interacts with 54-, 35- and 33-kDa proteins, which were identified by mass spectrometry as vimentin, voltage-dependent anion-selective channel protein (VDAC1), and annexin A2 isoform 2 (ANXA2), respectively, suggesting that the particles may bind and enter the cell through these proteins. The results presented here demonstrate that the SeMV NPs provide a new platform technology that could be used to develop in vivo imaging and targeted drug delivery agents for cancer diagnosis and therapy.

Montmorillonite as imaging and drug delivery agent for cancer therapy

Abstract Montmorillonite (Mt) can be used as a simultaneous medical imaging and drug delivery agent for transcatheter arterial embolization. In this technique, the arterial vessels around tumors are blocked by drug loaded micro-sized Mt particles so oxygen and nutrition from the blood flow are blocked and drugs are released by the particles into the tumor site. Both devascularization (achieved by cutting off the oxygen and the nutrition) and drug release around tumor site can result in the progressive shrinkage of the tumor size. Mt is highly applicable and unique for transcatheter arterial embolization due to the size, adsorption capability, and biocompatibility of the particles. Mt has been considered previously as a targeted drug delivery agent to the gastrointestinal tract only for oral applications due to its slow and sustained drug releasing properties, but it has not yet been investigated as a targeted drug delivery agent for tumors at different or highly-specific areas. In this study, interactions of purified montmorillonite (PMt) with a cone beam computer tomography (CT) contrast material and an antitumor drug were investigated to prepare drug releasing arterial embolic clay mineral particles that enable medical imaging. In-vitro studies were carried out to show the biocompatibility of PMt The swelling and adsorption properties of PMt in the presence of the CT contrast material or antitumor drug were investigated to find a proper concentration for possible embolization. The results show that both the CT contrast material and antitumor drug could penetrate to the interlayer spaces and were adsorbed by the surfaces of the PMt particles. The size of the PMt increased due to both the adsorption and coagulation, which made the particles suitable for the arterial embolization procedure where a specific particle size is required to successfully obtain embolization. In-vivo tests of PMt as a CT contrast carrier and in-vitro drug activity on MCF-7 (human breast adenocarcinoma) cells were also satisfactory using the prepared embolic PMt particles.

Manipulating multifaceted microbubble shell composition to target both TRAIL-sensitive and resistant cells.

This study represents the first attempt to combine surface TRAIL expression and doxorubicin co-encapsulation in a single drug delivery agent in the form of ultrasound-responsive microbubbles that shatter into fragments, or nanoshards, in an ultrasound beam. We compare customized microbubbles of different polymeric shell compositions, and investigate the effect of both shell composition and incorporation of doxorubicin on action against TRAIL-sensitive MDA-MB-231 and TRAIL-resistant MCF7 human breast adenocarcinoma cells. Ligation of TRAIL only significantly impacted MDA-MB-231 cells predominantly by apoptosis, and had minimal effect on MCF12A (normal control) cells. For all shell types, nanoshards had a greater effect (apoptotic death ranging from approximately 25% for 1 wt % LipidPEG to 50% for 100% PLA), reflecting the greater surface area and larger number of particles that ultrasound generates. Encapsulation of doxorubicin generated necrosis in all cell lines, but PEGylation produced less effective necrosis in all cell lines. Co-encapsulation of doxorubicin within the contrast agent shell increased MDA-MB-231 cell death to approximately 40-80%, representing a marked increase over TRAIL alone, reflecting the dramatic effect of shell composition. Additionally, shells that co-encapsulated TRAIL and doxorubicin resulted in approximately 30-60% death in TRAIL-resistant MCF7 human breast adenocarcinoma cells, compared with little apoptotic response in these cells from shells encapsulating TRAIL alone, demonstrating the sensitization effect of the drug. This work has resulted in production of a library of effective ultrasound-triggered, minimally immunogenic, targeted drug delivery agents for potential use in cancer therapy, and represents a promising multifaceted treatment to better serve the population with solid tumors. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1903-1915, 2018.

Drug Delivery from a Multi-faceted Ultrasound Contrast Agent: Influence of Shell Composition.

Many cancer therapy regimes still rely heavily on the systemic administration of toxic chemotherapeutic agents. Ultrasound contrast agents consisting of microbubbles (MBs) have emerged as a drug delivery vehicle to overcome the challenges associated with systemic chemotherapy. Here, we describe the development of non-immunogenic, functionalized polylactic acid (PLA) MBs for use in targeted cancer therapy. Our previous studies have shown that the balance between acoustic behavior and improved immune avoidance was scalable and successful to different degrees with two different PEGylation methods and was best achieved using incorporation of PEG-PLA at 5 wt % and for a LipidPEG at 1 wt %. Capitalizing on this, we now attach a targeting ligand, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which selectively induces tumor cell death upon binding to cancer cell-specific surface receptors, initiating a transmembrane apoptosis signal. Additionally, the functionalized MBs were designed to coencapsulate doxorubicin (Dox) that can be released from the polymer shell in response to ultrasound focused at the tumor site, shielding healthy tissues from toxicity while increasing the potency and efficiency of treatment to the tumor tissue. Ligation of TRAIL reduced the encapsulation efficiency for Dox compared to those of their non-ligated counterparts (p < 0.0001) by approximately 34% for 100% PLA, 23% for 5 wt % PEG-PLA, and 30% for the 1 wt % LipidPEG platform. All platforms exhibited a burst effect (<7%, p < 0.0001), and sustained release lasted for over 150 h. This work has resulted in a choice of effective ultrasound-triggered, non-immunogenic, targeted drug delivery agents for potential use in cancer therapy. These platforms have many advantages over the systemic administration of chemotherapeutic drugs and represent a promising treatment to better serve the population with solid cancerous tumors as a whole.

Generation and characterization of novel DNA aptamers against coat protein of grouper nervous necrosis virus (GNNV) with antiviral activities and delivery potential in grouper cells

Nervous necrosis virus (NNV) infected larvae and juveniles of more than 50 fish species, resulting in mortality rates of greater than 95%. However, there is no efficient method to control NNV infections. Aptamers generated by selective evolution of ligands by exponential enrichment (SELEX) are short, single-stranded nucleic acid oligomers. They display a high degree of affinity and specificity for many targets, such as viruses and viral proteins. In this study, three novel DNA aptamers (A5, A10, and B11) that specifically target the coat protein (CP) of grouper nervous necrosis virus (GNNV) were selected using SELEX. Secondary structures and minimum free energy (ΔG) predictions indicated that these aptamers could form stable, secondary stem-loop structures. Electrophoretic mobility shift assays, enzyme-linked immunosorbent assays, Kd measurements, the co-localization of tetramethylrhodamine (TAMRA) labeled-aptamers with the CP and flow cytometry analysis revealed that these aptamers could specifically bind the CP with high (nanomolar) affinities. In addition, competition analysis suggested the aptamers shared some common CP binding sites with the anti-CP antibody. Moreover, all three aptamers did not show any cytotoxic effects in vitro or in vivo, and anti-viral analysis indicated the selected aptamers could inhibit NNV infection in vitro and in vivo. Compared with controls, mortality of GNNV-infected fish decreased by 40% and 80% after 10 days infection, when the GNNV was pre-incubated with the 1000 nM A10 and B11, respectively. TAMRA-labeled aptamers could bind to NNV virions and directly enter NNV-infected cells, suggesting they could be used as tracers to study the mechanism of viral infection, as well as for targeted therapy. This is the first time that aptamers targeting a viral protein of marine fish have been generated and characterized. These aptamers hold promise as diagnostic, therapeutic, and targeted drug delivery agents for controlling NNV infections.

Perfluoroalkyl chains as tools for film surface nano-patterning and soft microbubble engineering and decoration

Molecular perfluoroalkylated components provide powerful tools for the elaboration, stabilization and control of organized nano- and micrometre scale soft matter constructs. The examples discussed here include patterning of thin interfacial films with self-assembled organized domains of fluorocarbon/hydrocarbon diblocks, formation and stabilization of size-controlled, resilient soft-shell microbubbles for ultrasound diagnostic imaging, and microbubbles self-assembled from a perfluoroalkylated amphiphile and decorated with iron oxide nanoparticles on their outer surface that are both highly echogenic and magnetic. The latter devices have potential as contrast agents for both ultrasound and magnetic resonance imaging, and as targeted drug delivery agents and devices.

Magnetic nanoparticle density mapping from the magnetically induced displacement data: a simulation study

BackgroundMagnetic nanoparticles are gaining great roles in biomedical applications as targeted drug delivery agents or targeted imaging contrast agents. In the magnetic nanoparticle applications, quantification of the nanoparticle density deposited in a specified region is of great importance for evaluating the delivery of the drugs or the contrast agents to the targeted tissues. We introduce a method for estimating the nanoparticle density from the displacement of tissues caused by the external magnetic field.MethodsWe can exert magnetic force to the magnetic nanoparticles residing in a living subject by applying magnetic gradient field to them. The nanoparticles under the external magnetic field then exert force to the nearby tissues causing displacement of the tissues. The displacement field induced by the nanoparticles under the external magnetic field is governed by the Navier's equation. We use an approximation method to get the inverse solution of the Navier's equation which represents the magnetic nanoparticle density map when the magnetic nanoparticles are mechanically coupled with the surrounding tissues. To produce the external magnetic field inside a living subject, we propose a coil configuration, the Helmholtz and Maxwell coil pair, that is capable of generating uniform magnetic gradient field. We have estimated the coil currents that can induce measurable displacement in soft tissues through finite element method (FEM) analysis.ResultsFrom the displacement data obtained from FEM analysis of a soft-tissue-mimicking phantom, we have calculated nanoparticle density maps. We obtained the magnetic nanoparticle density maps by approximating the Navier's equation to the Laplacian of the displacement field. The calculated density maps match well to the original density maps, but with some halo artifacts around the high density area. To induce measurable displacement in the living tissues with the proposed coil configuration, we need to apply the coil currents as big as 104A.ConclusionsWe can obtain magnetic nanoparticle maps from the magnetically induced displacement data by approximating the Navier's equation under the assumption of uniform-gradient of the external magnetic field. However, developing a coil driving system with the capacity of up to 104A should be a great technical challenge.