Stealth polycyanoacrylate nanoparticles as tumor necrosis factor-alpha carriers: pharmacokinetics and anti-tumor effects

Biocompatible alkyl cyanoacrylates and their derivatives as bio-adhesives

Cyanoacrylate adhesives and their homologues have elicited interest over the past few decades owing to their applications in the biomedical sector, extending from tissue adhesives to scaffolds to implants to dental material and adhesives, because of their inherent biocompatibility and ability to polymerize solely with moisture, thanks to which they adhere to any substrate containing moisture such as the skin.

Engineering the nanoparticle-protein interface for cancer therapeutics

Intracellular delivery of functional proteins using nanoparticles can be a game-changing approach for cancer therapy. However, cytosolic release of functional protein is still a major challenge. In addition, formation of protein corona on the surface of the nanoparticles can also alter the behavior of the nanoparticles. Here, we will review recent strategies for protein delivery into the cell. Finally we will discuss the issue of protein corona formation in light of nanoparticle-protein interactions.

Nanoparticle delivered vascular disrupting agents (VDAs): use of TNF-alpha conjugated gold nanoparticles for multimodal cancer therapy

Surgery, radiation and chemotherapy remain the mainstay of current cancer therapy. However, treatment failure persists due to the inability to achieve complete local control of the tumor and curtail metastatic spread. Vascular disrupting agents (VDAs) are a class of promising systemic agents that are known to synergistically enhance radiation, chemotherapy or thermal treatments of solid tumors. Unfortunately, there is still an unmet need for VDAs with more favorable safety profiles and fewer side effects. Recent work has demonstrated that conjugating VDAs to other molecules (polyethylene glycol, CNGRCG peptide) or nanoparticles (liposomes, gold) can reduce toxicity of one prominent VDA (tumor necrosis factor alpha, TNF-α). In this report, we show the potential of a gold conjugated TNF-α nanoparticle (NP-TNF) to improve multimodal cancer therapies with VDAs. In a dorsal skin fold and hindlimb murine xenograft model of prostate cancer, we found that NP-TNF disrupts endothelial barrier function and induces a significant increase in vascular permeability within the first 1-2 h followed by a dramatic 80% drop in perfusion 2-6 h after systemic administration. We also demonstrate that the tumor response to the nanoparticle can be verified using dynamic contrast-enhanced magnetic resonance imaging (MRI), a technique in clinical use. Additionally, multimodal treatment with thermal therapies at the perfusion nadir in the sub- and supraphysiological temperature regimes increases tumor volumetric destruction by over 60% and leads to significant tumor growth delays compared to thermal therapy alone. Lastly, NP-TNF was found to enhance thermal therapy in the absence of neutrophil recruitment, suggesting that immune/inflammatory regulation is not central to its power as part of a multimodal approach. Our data demonstrate the potential of nanoparticle-conjugated VDAs to significantly improve cancer therapy by preconditioning tumor vasculature to a secondary insult in a targeted manner. We anticipate our work to direct investigations into more potent tumor vasculature specific combinations of VDAs and nanoparticles with the goal of transitioning optimal regimens into clinical trials.

Targeted Delivery of Protein Drugs by Nanocarriers

Recent advances in biotechnology demonstrate that peptides and proteins are the basis of a new generation of drugs. However, the transportation of protein drugs in the body is limited by their high molecular weight, which prevents the crossing of tissue barriers, and by their short lifetime due to immuno response and enzymatic degradation. Moreover, the ability to selectively deliver drugs to target organs, tissues or cells is a major challenge in the treatment of several human diseases, including cancer. Indeed, targeted delivery can be much more efficient than systemic application, while improving bioavailability and limiting undesirable side effects. This review describes how the use of targeted nanocarriers such as nanoparticles and liposomes can improve the pharmacokinetic properties of protein drugs, thus increasing their safety and maximizing the therapeutic effect.

New approach to hydrophobic cyanine-type photosensitizer delivery using polymeric oil-cored nanocarriers: hemolytic activity, in vitro cytotoxicity and localization in cancer cells

We report on encapsulation of cyanine IR-768 in oil-in-water (o/w) microemulsion, i.e. fabrication of templated polymeric nanocapsules as effective nanocarriers for a new generation of photodynamic agents suitable for photodynamic therapy (PDT). Discussed here are nanocapsule imaging, their in vitro biological evaluation, cyanine encapsulation potential, and the cellular localization of cyanine IR-768 delivered in the nanocapsules to MCF-7 cancer cells. Oil-cored poly(n-butyl cyanoacrylate) (PBCA) nanocapsules were prepared by interfacial polymerization in o/w microemulsions formed by the nonionics Tween 80 (polysorbate 80, polyoxyethylene 20 sorbitan monooleate), and Brij 96 (polyoxyethylene 10 oleyl ether). Iso-propyl myristate (IPM), ethyl oleate (EOl), iso-octane (IO), and oleic acid (OA) were used as the oil phases and iso-propanol (IP) and propylene glycol (PG) as the cosurfactants. Such o/w droplets, also containing hydrophobic IR-768 in the oil phase, were applied in the interfacial polymerization of n-butyl cyanoacrylate at 10 degrees C at pH 5.0. The isolated cyanine-loaded nanoparticles were visualized by atomic force microscopy (AFM) and scanning electron microscopy (SEM), which proved their unimodal size distribution and spherical shape, with diameters dependent upon the monomer content and the template type. The entrapment efficiency of cyanine increased with increasing n-butyl cyanoacrylate concentration and varied from 65.7% to 91.7%. The results of in vitro erythrocyte hemolysis and the cell viability of breast cancer MCF-7 cells showed that the PBCA nanocapsules are quite safe carriers of IR-768 in the circulation, having a very low hemolytic potential and being non-toxic to the studied cells. Fluorescence microscopy visualized the cyanine intracellular distribution and, furthermore, demonstrated that PBCA-nanocarriers effectively delivered the IR-768 molecules to the MCF-7 doxorubicin-sensitive and -resistant cell lines. Photoirradiation of the cancer cells with entrapped photosensitizer decreased cell viability, demonstrating that this effect may be utilized in PDT.

Design aspects of poly(alkylcyanoacrylate) nanoparticles for drug delivery

Poly(alkylcyanoacrylate) (PACA) nanoparticles were first developed 25 years ago taking advantage of the in vivo degradation potential of the polymer and of its good acceptance by living tissues. Since then, various PACA nanoparticles were designed including nanospheres, oil-containing and water-containing nanocapsules. This made possible the in vivo delivery of many types of drugs including those presenting serious challenging delivery problems. PACA nanoparticles were proven to improve treatments of severe diseases like cancer, infections and metabolic disease. For instance, they can transport drugs across barriers allowing delivery of therapeutic doses in difficult tissues to reach including in the brain or in multidrug resistant cells. This review gives an update on the more recent developments and achievements on design aspects of PACA nanoparticles as delivery systems for various drugs to be administered in vivo by different routes of administration.

Enhancing the tolerance of poly(isobutylcyanoacrylate) nanoparticles with a modular surface design

Polymer nanoparticles are designed as nanovehicles to carry drugs in the body in a controlled manner increasing the concentration of the biologically active substance in the diseased organs and cells. The safety and biocompatibility of these nanosystems are those of the many properties that nanoparticles must meet to be used in vivo. Here we show that the cytotoxicity profile of poly(isobutylcyanoacrylate) (PIBCA) nanoparticles is affected by the way the nanosystems were produced and by the design of their surface. It was found that the tolerance of PIBCA nanoparticles by cells could be improved up to 100-fold by coating their surface with polysaccharides and haemoglobin.

Bioadhesive properties of pegylated nanoparticles

The design of bioadhesive nanoparticles (NPs) for targeting specific sites within the gut remains a major challenge. One possible strategy to solve this problem may be the use of pegylated NPs. In general, these carriers display different bioadhesive properties to nondecorated NPs. Thus, pegylated NPs show a higher ability to interact with the small intestine mucosa rather than with the stomach. However, the type of surface conformation of polyethylene glycol chains appears to have a great influence on the behaviour of these NPs. Theoretically, the traditional 'brush' polyethylene glycol corona would facilitate the penetration of the pegylated particles through the mucus layer and the subsequent adhesive interaction with the mucosa, which would promote their absorption by intestinal enterocytes. On the contrary, pegylated NPs with a 'loop' conformation would increase the time of residence of the adhered fraction of particles in the mucosa.

Stealth PEG-PHDCA niosomes: Effects of Chain Length of PEG and Particle Size on Niosomes Surface Properties, In Vitro Drug Release, Phagocytic Uptake, In Vivo Pharmacokinetics and Antitumor Activity

A series of novel niosomes with the amphiphilic copolymer of poly (methoxy-polyethyleneglycol cyanoacrylate-co-n-hexadecyl cyanoacrylate) (PEG-PHDCA) acted as surface modification materials were prepared and Hydroxycamptothecin (HCPT) was used as a model drug. This work concentrated on the effects of PEG chain length and particle sizes on the niosomes surface properties, in vitro drug release, phagocytic uptake, in vivo pharmacokinetics and antitumor activity. Within the range of PEG Mw from 2000 to 10000, the increasing zeta potential (from -16.08 to -5.25 mv) and thicker fixed aqueous layer (3.82 to 5.78 nm) would facilitate the niosomes' stealth effects, while the reduced PEG chain density (from 0.53 to 0.17 PEG/nm2) and the quickened speed of drug release would diminish the effects. As a result, the PEG5000-PHDCA niosomes had the least phagocytic uptake, the longest half-life of 11.46 h and the best tumor inhibition rate of 97.1%. In the groups different in particle size (PEG5000-PHDCA niosomes from 92.5 to 204.6 nm), the bigger particles could be uptaken by macrophages more quickly, regardless of the changes of other physicochemical parameters. Correspondingly, PEG5000-PHDCA niosomes with particle sizes of 92.5, 144.2, 204.6 nm could extend the half-life of HCPT to 11.46, 6.33, 4.46 h, respectively. At last, the tumor inhibition rate of PEG5000-PHDCA niosomes (92.5 nm) at a dose of 2 mg/kg was five times that of HCPT injection at 4 mg/kg. The stealth effects of the PEG-PHDCA niosomes and the enhanced stability of lactone form of HCPT were accountable for the powerful antitumor effects of niosomes.

In vivo tumor targeting of tumor necrosis factor-alpha-loaded stealth nanoparticles: effect of MePEG molecular weight and particle size

The aim of this study is to reveal the influence of methoxypolyethyleneglycol (MePEG) molecular weight and particle size of stealth nanoparticles on their in vivo tumor targeting properties. Three sizes (80, 170 and 240nm) of poly methoxypolyethyleneglycol cyanoacrylate-co-n-hexadecyl cyanoacrylate (PEG-PHDCA) nanoparticles loading recombinant human tumor necrosis factor-alpha (rHuTNF-alpha) were prepared at different MePEG molecular weights (MW=2000, 5000 and 10,000) using double emulsion method. The opsonization in mouse serum was evaluated by Coomassie brilliant blue staining of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Phagocytosis was evaluated by incubating (125)I-rHuTNF-alpha-loaded nanoparticles with mouse macrophages (RAW264.7). The pharmacokinetics, biodistribution and tumor targeting studies were performed in S-180 tumor-bearing mice. Higher MePEG molecular weight provided thicker fixed aqueous layer thickness (FALT) and smaller particle size offered higher surface MePEG density. The serum protein adsorption and phagocytic uptake were markedly decreased for the nanoparticles with higher MePEG molecular weight or smaller size. The particles (80nm) made of PEG(5000)-PHDCA, possessing a thicker FALT (5.16nm) and a shortest distance (0.87nm) between two neighboring MePEG chains, showed the strongest capacity of decreasing protein adsorption and phagocytic uptake. These particles extended the half-life of rHuTNF-alpha in S-180 tumor-bearing mice by 24-fold (from 28.2 min to 11.33 h), elevated the rHuTNF-alpha peak concentration in S-180 tumors by 2.85-fold and increased the area under the intratumoral rHuTNF-alpha concentration curve by 7.44-fold. The results of the present study showed PEG-PHDCA nanoparticles with higher MePEG molecular weight and smaller particle size could achieve higher in vivo tumor targeting efficiency.

Effect of MePEG molecular weight and particle size on in vitro release of tumor necrosis factor-alpha-loaded nanoparticles

AIM

To study the in vitro release of recombinant human tumor necrosis factor-alpha (rHuTNF-alpha) encapsulated in poly (methoxypolyethyleneglycol cyanoacrylate-co-n-hexadecyl cyanoacrylate) (PEG-PHDCA) nanoparticles, and investigate the influence of methoxypolyethyleneglycol (MePEG) molecular weight and particle size.

METHODS

Three sizes (approximately 80, 170, and 240 nm) of PEG-PHDCA nanoparticles loading rHuTNF-alpha were prepared at different MePEG molecular weights (M(r) =2000, 5000, and 10,000) using the double emulsion method. The in vitro rHuTNF-alpha release was studied in PBS and rat plasma.

RESULTS

A higher burst-release and cumulative-release rate were observed for nanoparticles with higher MePEG molecular weight or smaller particle size. A decreased cumulative release of rHuTNF-alpha following the initial burst effect was found in PBS, while the particle sizes remained constant and MePEG liberated. In contrast, in rat plasma, slowly increased cumulative-release profiles were obtained after the burst effect. During a 5-h incubation in rat plasma, more than 50% of the PEG-PHDCA nanoparticles degraded.

CONCLUSION

The MePEG molecular weight and particle size had an obvious influence on rHuTNF-alpha release. rHuTNF-alpha released from PEG-PHDCA nanoparticles in a diffusion-based pattern in PBS, but in a diffusion and erosion-controlled manner in rat plasma.

In vitro and in vivo evaluation of actively targetable nanoparticles for paclitaxel delivery

The aim of the present work was to assess the merits of an actively targetable nanoparticles (ATN), PEG-coated biodegradable polycyanoacrylate nanoparticles (PEG-nanoparticles) conjugated to transferrin, for paclitaxel delivery. PEG-nanoparticles loading paclitaxel were prepared by solvent evaporation technique in advance. ATN were prepared by coupling of transferrin to PEG-nanoparticles. The results showed that the average encapsulation efficiency of ATN was 93.4+/-3.6% with particle size (101.4+/-7.2 nm) and zeta-potential (-13.6+/-1.1 mV). The paclitaxel loaded ATN exhibited a low burst effect with about only 16.2% drug release within the first phase. Subsequently, paclitaxel release profiles displayed a sustained release phase. The amount of cumulated paclitaxel release over 30 days was 81.6%. ATN exhibited a markedly delayed blood clearance in mice, and the paclitaxel level from ATN remained much higher at 24 h compared with that of free drug from paclitaxel injection. The distribution profiles of ATN in S-180 solid tumor-bearing mice after intravenous administration showed the tumor accumulation of paclitaxel increase with time, and the paclitaxel concentration in tumor was about 4.8 and 2.1 times higher than those from paclitaxel injection and PEG-nanoparticles at 6 h after intravenous injection. For mice treated with 20 mg/kg x 5 of ATN, the decrease in body weight was limited within 4% of the initial weight at 5 days after the final administration, and tumor regression was significantly observed with complete tumor regression for five out of nine mice. The tumor burden with ATN-treated mice was much smaller compared with free paclitaxel or NTN-treated mice. In addition, the life span of tumor-bearing mice was significantly increased when they were treated with ATN, in particular, three mice survived over 60 days. Thus, PEG-coated biodegradable polycyanoacrylate nanoparticles conjugated to transferrin could be an effective carrier for paclitaxel delivery.

Preparation of magnetic polybutylcyanoacrylate nanospheres encapsulated with aclacinomycin A and its effect on gastric tumor

AIM

To evaluate the effect of aclacinomycin A-loaded magnetic polybutylcyanoacrylate nanoparticles on gastric tumor growth in vivo and in vitro.

METHODS

Magnetic polybutylcyanoacrylate (PBCA) nanospheres encapsulated with aclacinomycin A (MPNS-ACM) were prepared by interfacial polymerization. Particle size, shape and drug content were examined. Female BABL/c nude mice were implanted with MKN-45 gastric carcinoma tissues subcutaneously to establish human gastric carcinoma model. The mice were randomly divided into 5 groups of 6 each: ACM group (8 mg/kg bm); group of high dosage of MPNS-ACM (8 mg/kg bm); group of low dosage of MPNS-ACM (1.6 mg/kg bm); group of magnetic PBCA nanosphere (MPNS) and control group (normal saline). Magnets (2.5 T) were implanted into the tumor masses in all of the mice one day before the therapy. Above-mentioned drugs were administered intravenously to the mice of every group on the first day and sixth day. When the mice were sacrificed, tumor weight was measured, and the assay of granulocyte- macrophage colony forming-unit (CFU-GM) was performed on semi-solid culture. White blood cell, alanine aminotransferase and creatine were examined. 3-(4-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used to examine the viability of MKN-45 cells after incubation with different concentrations of ACM, MPNS and MPNS-ACM suspension respectively for 48 h.

RESULTS

Content of ACM in MPNS-ACM was 12.0% and the average diameter of the particles was 210 nm. The inhibitory rates of ACM (8 mg/kg bm), high dosage of MPNS-ACM (8 mg/kg bm), low dosage of MPNS-ACM (1.6 mg/kg bm) and MPNS on human gastric carcinoma in nude mice were 22.63%, 52.55%, 30.66% and 10.22%, respectively. There was a significant decrease in the number of CFU-GM of bone marrow in ACM group compared with control group, whereas no obvious change was observed in that of the nanosphere groups. The values of 50% inhibition concentration (IC50) of ACM, MPNS and MPNS-ACM were 0.09, 97.78 and 1.07 microg/mL, respectively.

CONCLUSION

The tumor inhibitory rate of MPNS-ACM was much higher than that of ACM under magnetic field and the inhibition on bone marrow was alleviated significantly compared with ACM group.

Poly(alkylcyanoacrylates) as biodegradable materials for biomedical applications

This review considers the use of poly(alkylcyanoacrylates) (PACAs) as biomedical materials. We first present the different aspects of the polymerization of alkylcyanoacrylate monomers and briefly discuss their applications as skin adhesives, surgical glues and embolitic materials. An extensive review of the developments and applications of PACAs as nanoparticles for the delivery of drugs is then given. The methods of preparation of the nanoparticles are presented and considerations concerning the degradation, in vivo distribution, toxicity and cytotoxicity of the nanoparticles are discussed. The different therapeutic applications are presented according to the route of administration of the nanoparticles and include the most recent developments in the field.