Docetaxel-loaded polyglutamic acid-PEG nanocapsules for the treatment of metastatic cancer

Facile Synthesis of High Molecular Weight Poly(ethylene glycol)-b-poly(amino acid)s by Relay Polymerization

Poly(amino acid)s (PAAs) are one kind of favorable biopolymer that can be used as a drug or gene carrier. However, conventional ring-opening polymerization of PAAs is slow and needs a strict anhydrous environment with an anhydrous reagent as well as the product without enough high molecular weight (Mn), which limits the expanding of PAAs' application. Herein, we took BLG-NCA as the monomer to quickly synthesize one kind of high Mn amphiphilic copolymer, poly(ethylene glycol)-b-poly(γ-benzyl-l-glutamic acid) (PEG-PBLG), by relay polymerization with a simple one-pot method within 3 h in mild conditions (open air, moisture insensitive). In the polymerization process, ring-opening polymerization-induced self-assembly in sodium bicarbonate aqueous solution first occurred to obtain low Mn PEG-PBLG seeds without purification. Then γ-benzyl-l-glutamate N-carboxyanhydride (BLG-NCA) dichloromethane solution was added into PEG-PBLG seeds directly and stirred vigorously to form am emulsion; during this process, the amphiphilic PEG-PBLG seeds will anchor on the interface of DCM and water to ensure the concentration of α-helix rigid PBLG in DCM to maintain the following relay polymerization. Then, high Mn PEG-PBLG was obtained in mild conditions in one pot. We found that the α-helix rigid structure was essential for relay polymerization by studying the synthetic speed of amphiphilic copolymer with different secondary structures. MOE simulation results showed that PBLG and BLG-NCA tended to form a double hydrogen bond, which was beneficial to relay polymerization because of higher local concentrations that can produce more double hydrogen bonds. Our strategy can quickly obtain high Mn PEG-PBLG (224.9 KDa) within 3 h from PEG-NH2 and BLG-NCA in one pot and did not need an extra initiator. After deprotection, the poly(ethylene glycol)-b-poly(l-glutamate acid) (PEG-PGA) with high Mn as a second product can be used as an excellent antitumor drug carrier. The high Mn PEG-PGA can achieve an encapsulation rate of 86.7% and a drug loading rate of 47.3%, which is twice that of the low Mn PEG-PGA. As a result, the synthesis of PEG-PBLG by relay polymerization simplified the process of PEG-PAA polymerization and increased the Mn. In addition, this method opened a way to obtain other kinds of high Mn PEG-PBLG values in the future.

Polymeric nanocapsules loaded with poly(I:C) and resiquimod to reprogram tumor-associated macrophages for the treatment of solid tumors

Background

In the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play a key immunosuppressive role that limits the ability of the immune system to fight cancer. Toll-like receptors (TLRs) ligands, such as poly(I:C) or resiquimod (R848) are able to reprogram TAMs towards M1-like antitumor effector cells. The objective of our work has been to develop and evaluate polymeric nanocapsules (NCs) loaded with poly(I:C)+R848, to improve drug stability and systemic toxicity, and evaluate their targeting and therapeutic activity towards TAMs in the TME of solid tumors.

Methods

NCs were developed by the solvent displacement and layer-by-layer methodologies and characterized by dynamic light scattering and nanoparticle tracking analysis. Hyaluronic acid (HA) was chemically functionalized with mannose for the coating of the NCs to target TAMs. NCs loaded with TLR ligands were evaluated in vitro for toxicity and immunostimulatory activity by Alamar Blue, ELISA and flow cytometry, using primary human monocyte-derived macrophages. For in vivo experiments, the CMT167 lung cancer model and the MN/MCA1 fibrosarcoma model metastasizing to lungs were used; tumor-infiltrating leukocytes were evaluated by flow cytometry and multispectral immunophenotyping.

Results

We have developed polymeric NCs loaded with poly(I:C)+R848. Among a series of 5 lead prototypes, protamine-NCs were selected based on their physicochemical properties (size, charge, stability) and in vitro characterization, showing good biocompatibility on primary macrophages and ability to stimulate their production of T-cell attracting chemokines (CXCL10, CCL5) and to induce M1-like macrophages cytotoxicity towards tumor cells. In mouse tumor models, the intratumoral injection of poly(I:C)+R848-protamine-NCs significantly prevented tumor growth and lung metastasis. In an orthotopic murine lung cancer model, the intravenous administration of poly(I:C)+R848-prot-NCs, coated with an additional layer of HA-mannose to improve TAM-targeting, resulted in good antitumoral efficacy with no apparent systemic toxicity. While no significant alterations were observed in T cell numbers (CD8, CD4 or Treg), TAM-reprogramming in treated mice was confirmed by the relative decrease of interstitial versus alveolar macrophages, having higher CD86 expression but lower CD206 and Arg1 expression in the same cells, in treated mice.

Conclusion

Mannose-HA-protamine-NCs loaded with poly(I:C)+R848 successfully reprogram TAMs in vivo, and reduce tumor progression and metastasis spread in mouse tumors.

Targets, Mechanisms and Cytotoxicity of Half-Sandwich Ir(III) Complexes Are Modulated by Structural Modifications on the Benzazole Ancillary Ligand

Cancers are driven by multiple genetic mutations but evolve to evade treatments targeting specific mutations. Nonetheless, cancers cannot evade a treatment that targets mitochondria, which are essential for tumor progression. Iridium complexes have shown anticancer properties, but they lack specificity for their intracellular targets, leading to undesirable side effects. Herein we present a systematic study on structure-activity relationships of eight arylbenzazole-based Iridium(III) complexes of type [IrCl(Cp*)], that have revealed the role of each atom of the ancillary ligand in the physical chemistry properties, cytotoxicity and mechanism of biological action. Neutral complexes, especially those bearing phenylbenzimidazole (HL1 and HL2), restrict the binding to DNA and albumin. One of them, complex 1[C,NH-Cl], is the most selective one, does not bind DNA, targets exclusively the mitochondria, disturbs the mitochondria membrane permeability inducing proton leak and increases ROS levels, triggering the molecular machinery of regulated cell death. In mice with orthotopic lung tumors, the administration of complex 1[C,NH-Cl] reduced the tumor burden. Cancers are more vulnerable than normal tissues to a treatment that harnesses mitochondrial dysfunction. Thus, complex 1[C,NH-Cl] characterization opens the way to the development of new compounds to exploit this vulnerability.

Hydrophilic Poly(glutamic acid)-Based Nanodrug Delivery System: Structural Influence and Antitumor Efficacy

Poly(amino acids) have advanced characteristics, including unique secondary structure, enzyme degradability, good biocompatibility, and stimuli responsibility, and are suitable as drug delivery nanocarriers for tumor therapy. The isoform structure of poly(amino acids) plays an important role in their antitumor efficacy and should be researched in detail. In this study, two kinds of pH-sensitive isoforms, including α-poly(glutamic acid) (α-PGA) and γ-PGA, were selected and used as nanocarriers to prepare a nanodrug delivery system. According to the preparation results, α-PGA can be used as an ideal drug carrier. Selecting doxorubicin (DOX) as the model drug, an α-PGA/DOX nanoparticle (α-PGA/DOX NPs) with a particle size of 110.4 nm was prepared, and the drug-loading content was 66.2%. α-PGA/DOX NPs presented obvious sustained and pH-dependent release characteristics. The IC50 value of α-PGA/DOX NPs was 1.06 ± 0.77 μg mL-1, decreasing by approximately 8.5 fold in vitro against 4T1 cells after incubation for 48 h. Moreover, α-PGA/DOX NPs enhanced antitumor efficacy in vivo, the tumor inhibition rate was 67.4%, increasing 1.5 fold over DOX injection. α-PGA/DOX NPs also reduced the systemic toxicity and cardiotoxicity of DOX. In sum, α-PGA is a biosafe nanodrug delivery carrier with potential clinical application prospects.

Smart Nanotherapeutics and Lung Cancer

Lung cancer is a significant health problem worldwide. Unfortunately, current therapeutic strategies lack a sufficient level of specificity and can harm adjacent healthy cells. Consequently, to address the clinical need, novel approaches to improve treatment efficiency with minimal side effects are required. Nanotechnology can substantially contribute to the generation of differentiated products and improve patient outcomes. Evidence from previous research suggests that nanotechnology-based drug delivery systems could provide a promising platform for the targeted delivery of traditional chemotherapeutic drugs and novel small molecule therapeutic agents to treat lung cancer cells more effectively. This has also been found to improve the therapeutic index and reduce the required drug dose. Nanodrug delivery systems also provide precise control over drug release, resulting in reduced toxic side effects, controlled biodistribution, and accelerated effects or responses. This review highlights the most advanced and novel nanotechnology-based strategies, including targeted nanodrug delivery systems, stimuli-responsive nanoparticles, and bio-nanocarriers, which have recently been employed in preclinical and clinical investigations to overcome the current challenges in lung cancer treatments.

Recent advances in polymer shell oily-core nanocapsules for drug-delivery applications

Polymeric nanocapsules are vesicular drug-delivery systems composed of an inner oily reservoir surrounded by polymeric membranes. Nanocapsules have various advantages over other nanovesicular systems such as providing controlled drug release properties. We discuss the recent advances in polymeric shell oily-core nanocapsules, illustrating the different types of polymers used and their implementation. Nanocapsules can be utilized for many purposes, especially encapsulation of highly lipophilic drugs. They have been shown to have variable applications, especially in cancer therapy, due to the ability of the polymeric shell to direct the loaded drugs to their target sites, as well as their high internalization efficacy. Those productive applications guaranteed their high potential as drug-delivery systems. However, their clinical development is still in an early stage.

Albumin-Coated Mesoporous Silica Nanoparticles of Docetaxel: Preparation, Characterization, and Pharmacokinetic Evaluation

The potential of albumin-coated hollow mesoporous silica nanoparticles (A-HMSNs) to optimize the chemotherapeutic efficacy of docetaxel (DTX) was explored. The synthesized A-DTX-HMSNs had a nanometric size range, offered large surface area with numerous pores, and offered high drug entrapment and loading, that is, 79.18% ± 1.4% and 19.11% ± 1.30%, respectively. Fourier transform infrared spectroscopy and differential scanning calorimetry studies confirmed drug loading and the presence of albumin onto the developed systems, and the drug release followed Higuchi profile. A-HMSNs significantly enhanced the pharmacokinetic profile of DTX by eightfold vis-à-vis the pure DTX. The enhanced plasma levels (C_max, T_max, area under the curve), prolonged drug release, long circulation time, lower clearance, hemocompatability, and substantially higher drug loading offered by these nanocarriers inherit promise of a safer and efficacious formulation of DTX.

Docetaxel in chitosan-based nanocapsules conjugated with an anti-Tn antigen mouse/human chimeric antibody as a promising targeting strategy of lung tumors

The aim of this work was to evaluate the physicochemical and biological properties of docetaxel (DCX) loaded chitosan nanocapsules (CS Nc) functionalized with the monoclonal antibody Chi-Tn (CS-PEG-ChiTn mAb Nc) as a potential improvement treatment for cancer therapy. The Tn antigen is highly specific for carcinomas, and this is the first time that such structure is targeted for drug delivery. The nanocapsules (Ncs), formed as a polymeric shell around an oily core, allowed a 99.9% encapsulation efficiency of DCX with a monodispersity particle size in the range of 200 nm and a high positive surface charge that provide substantial stability to the nanosystems. Release profile of DCX from Ncs showed a sustained and pH dependent behavior with a faster release at acidic pH, which could be favorable in the intracellular drug delivery. We have designed PEGylated CS Nc modified with a monoclonal antibody which recognize Tn antigen, one of the most specific tumor associated antigen. A biotin-avidin approach achieved the successful attachment of the antibody to the nanocapsules. Uptake studies and viability assay conducted in A549 human lung cancer cell line in vitro demonstrate that ChiTn mAb enhance nanoparticles internalization and cell viability reduction. Consequently, these ChiTn functionalized nanocapsules are promising carriers for the active targeting of DCX to Tn expressing carcinomas.

Recent advances in combination of microneedles and nanomedicines for lymphatic targeted drug delivery

Numerous diseases have been reported to affect the lymphatic system. As such, several strategies have been developed to deliver chemotherapeutics to this specific network of tissues and associated organs. Nanotechnology has been exploited as one of the main approaches to improve the lymphatic uptake of drugs. Different nanoparticle approaches utilized for both active and passive targeting of the lymphatic system are discussed here. Specifically, due to the rich abundance of lymphatic capillaries in the dermis, particular attention is given to this route of administration, as intradermal administration could potentially result in higher lymphatic uptake compared to other routes of administration. Recently, progress in microneedle research has attracted particular attention as an alternative for the use of conventional hypodermic injections. The benefits of microneedles, when compared to intradermal injection, are subsequently highlighted. Importantly, microneedles exhibit particular benefit in relation to therapeutic targeting of the lymphatic system, especially when combined with nanoparticles, which are further discussed. However, despite the apparent benefits provided by this combination approach, further comprehensive preclinical and clinical studies are now necessary to realize the potential extent of this dual-delivery platform, further taking into consideration eventual usability and acceptability in the intended patient end-users. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

PH and redox dual-responsive polymeric micelles with charge conversion for paclitaxel delivery

Here we demonstrate a type of pH and redox dual-responsive micelles, which were self-assembled in aqueous solution by an amphiphilic polymer, methoxypoly(ethylene glycol)-cystamine-poly(L-glutamic acid)-imidazole (mPEG-SS-PGA-IM). Considering tumor cells or tissues exhibiting low pH values and high glutathione (GSH) concentration, mPEG-SS-PGA-IM micelles possessed the charge conversion at pH of tumor tissues, which can facilitate cellular uptake of tumor cells. Furthermore, mPEG-SS-PGA-IM micelles can escape from endo/lysosomes based on the proton sponge effect, following degraded by higher concentration of GSH in cytoplasm. CLSM images of HCT116 cells indicated that mPEG-SS-PGA-IM micelles can escape from endo/lysosomes and enter cytoplasm. MTT assay showed that (paclitaxel) PTX-loaded mPEG-SS-PGA-IM micelles had higher cytotoxicity against HCT116 cells compared with PTX-loaded mPEG-PBLG and mPEG-SS-PBLG micelles. These results indicated that these mPEG-SS-PGA-IM micelles, as novel and effective pH- and redox-responsive nanocarriers, have great potential to both improve drug targeting efficiency while also enhancing the antitumor efficacy of PTX.

Arginine-Based Poly(I:C)-Loaded Nanocomplexes for the Polarization of Macrophages Toward M1-Antitumoral Effectors

Background: Tumor-associated macrophages (TAMs), with M2-like immunosuppressive profiles, are key players in the development and dissemination of tumors. Hence, the induction of M1 pro-inflammatory and anti-tumoral states is critical to fight against cancer cells. The activation of the endosomal toll-like receptor 3 by its agonist poly(I:C) has shown to efficiently drive this polarization process. Unfortunately, poly(I:C) presents significant systemic toxicity, and its clinical use is restricted to a local administration. Therefore, the objective of this work has been to facilitate the delivery of poly(I:C) to macrophages through the use of nanotechnology, that will ultimately drive their phenotype toward pro-inflammatory states.

Methods: Poly(I:C) was complexed to arginine-rich polypeptides, and then further enveloped with an anionic polymeric layer either by film hydration or incubation. Physicochemical characterization of the nanocomplexes was conducted by dynamic light scattering and transmission electron microscopy, and poly(I:C) association efficiency by gel electrophoresis. Primary human-derived macrophages were used as relevant in vitro cell model. Alamar Blue assay, ELISA, PCR and flow cytometry were used to determine macrophage viability, polarization, chemokine secretion and uptake of nanocomplexes. The cytotoxic activity of pre-treated macrophages against PANC-1 cancer cells was assessed by flow cytometry.

Results: The final poly(I:C) nanocomplexes presented sizes lower than 200 nm, with surface charges ranging from +40 to −20 mV, depending on the envelopment. They all presented high poly(I:C) loading values, from 12 to 50%, and great stability in cell culture media. In vitro, poly(I:C) nanocomplexes were highly taken up by macrophages, in comparison to the free molecule. Macrophage treatment with these nanocomplexes did not reduce their viability and efficiently stimulated the secretion of the T-cell recruiter chemokines CXCL10 and CCL5, of great importance for an effective anti-tumor immune response. Finally, poly(I:C) nanocomplexes significantly increased the ability of treated macrophages to directly kill cancer cells.

Conclusion: Overall, these enveloped poly(I:C) nanocomplexes might represent a therapeutic option to fight cancer through the induction of cytotoxic M1-polarized macrophages.

Preparation and characterization of lamotrigine containing nanocapsules for nasal administration

Nanocapsules (NCs) have become one of the most researched nanostructured drug delivery systems due to their advantageous properties and versatility. NCs can enhance the bioavailabiliy of hydrophobic drugs by impoving their solubility and permeability. Also, they can protect these active pharmaceutical agents (APIs) from the physiological environment with preventing e.g. the enzymatic degradation. NCs can be used for many administration routes: e.g. oral, dermal, nasal and ocular formulations are exisiting in liquid and solid forms. The nose is one of the most interesting alternative drug administration route, because local, systemic and direct central nervous system (CNS) delivery can be achived; this could be utilized in the therapy of CNS diseases. Therefore, the goal of this study was to design, prepare and investigate a novel, lamotrigin containing NC formulation for nasal administration. The determination of micrometric parameters (particle size, polydispersity index, surface charge), in vitro (drug loading capacity, release and permeability investigations) and in vivo characterization of the formulations were performed in the study. The results indicate that the formulation could be a promising alternative of lamotrigine (LAM) as the NCs were around 305 nm size with high encapsulation efficiency (58.44%). Moreover, the LAM showed rapid and high release from the NCs in vitro and considerable penetration to the brain tissues was observed during the in vivo study.

A novel low molecular weight nanocomposite hydrogel formulation for intra-tumoural delivery of anti-cancer drugs

Herein, an injectable formulation composed of a low molecular weight gelator (LMWG) based hydrogel and drug-loaded polymeric nanocapsules (NCs) is described. The NCs, made of hyaluronic acid and polyglutamic acid and loaded with C14-Gemcitabine (GEM C14), showed a size of 40 and 80 nm and a encapsulation efficiency >90%. These NCs exhibited a capacity to control the release of the encapsulated drug for >1 month. GEM C14-loaded NCs showed activity against various cancer cell lines in vitro; cell growth inhibition by 50% (GI₅₀) values of 15 ± 6, 10 ± 9, 13 ± 3 and 410 ± 463 nM were obtained in HCT 116, MIA PaCa-2, Panc-1 and Panc-1 GEM resistant cell lines respectively. Nanocomposite hydrogels were prepared using the LMWG - N4-octanoyl-2'-deoxycytidine and loaded for the first time with polymeric NCs. 2% and 4% w/v nanocapsule concentrations as compared to 8% w/v NC concentrations with 2% and 3% w/v gelator concentrations gave mechanically stronger gels as determined by oscillatory rheology. Most importantly, the nanocomposite formulation reformed instantly into a gel after injection through a needle. Based on these properties, the nanocomposite gel formulation has potential for the intratumoural delivery of anticancer drugs.

Lymphatic changes in cancer and drug delivery to the lymphatics in solid tumors

Although many solid tumors use the lymphatic system to metastasize, there are few treatment options that directly target cancer present in the lymphatic system, and those that do are highly invasive, uncomfortable, and/or have limitations. In this review we provide a brief overview of lymphatic function and anatomy, discusses changes that befall the lymphatics in cancer and the mechanisms by which these changes occur, and highlight limitations of lymphatic drug delivery. We then go on to summarize relevant techniques and new research for targeting cancer populations in the lymphatics and enhancing drug delivery intralymphatically, including intralymphatic injections, isolated limb perfusion, passive nano drug delivery systems, and actively targeted nanomedicine.

Docetaxel-loaded human serum albumin (HSA) nanoparticles: synthesis, characterization, and evaluation

Background

Docetaxel (DTX) is an anticancer drug that is currently formulated with polysorbate 80 and ethanol (50:50, v/v) in clinical use. Unfortunately, this formulation causes hypersensitivity reactions, leading to severe side-effects, which have been primarily attributed to polysorbate 80.

Methods

In this study, a DTX-loaded human serum albumin (HSA) nanoparticle (DTX-NP) was designed to overcome the hypersensitivity reactions that are induced by polysorbate 80. The methods of preparing the DTX-NPs have been optimized based on factors including the drug-to-HSA weight ratio, the duration of HSA incubation, and the choice of using a stabilizer. Synthesized DTX-NPs were characterized with regard to their particle diameters, drug loading capacities, and drug release kinetics. The morphology of the DTX-NPs was observed via scanning electron microscopy (SEM) and the successful preparation of DTX-NPs was confirmed via differential scanning calorimetry (DSC). The cytotoxicity and cellular uptake of DTX-NPs were investigated in the non-small cell lung cancer cell line A549 and the maximum tolerated dose (MTD) of DTX-NPs was evaluated via investigations with BALB/c mice.

Results

The study showed that the loading capacity and the encapsulation efficiency of DTX-NPs prepared under the optimal conditions was 11.2 wt% and 63.1 wt%, respectively and the mean diameter was less than 200 nm, resulting in higher permeability and controlled release. Similar cytotoxicity against A549 cells was exhibited by the DTX-NPs in comparison to DTX alone while higher maximum tolerated dose (MTD) with the DTX-NPs (75 mg/kg) than with DTX (30 mg/kg) was demonstrated in mice, suggesting that the DTX-NPs prepared with HSA yielded similar anti-tumor activity but were accompanied by less systemic toxicity than solvent formulated DTX.

Conclusions

DTX-NPs warrant further investigation and are promising candidates for clinical applications.

Engineering, on-demand manufacturing, and scaling-up of polymeric nanocapsules

Polymeric nanocapsules are versatile delivery systems with the capacity to load lipophilic drugs in their oily nucleus and hydrophilic drugs in their polymeric shell. The objective of this work was to expand the technological possibilities to prepare customized nanocapsules. First, we adapted the solvent displacement technique to modulate the particle size of the resulting nanocapsules in the 50-500 nm range. We also produced nanosystems with a shell made of one or multiple polymer layers i.e. chitosan, dextran sulphate, hyaluronate, chondroitin sulphate, and alginate. In addition, we identified the conditions to translate the process into a miniaturized high-throughput tailor-made fabrication that enables massive screening of formulations. Finally, the production of the nanocapsules was scaled-up both in a batch production, and also using microfluidics. The versatility of the properties of these nanocapsules and their fabrication technologies is expected to propel their advance from bench to clinic.

A multifunctional drug nanocarrier for efficient anticancer therapy

So far, the success of anticancer nanomedicines has been moderate due to their lack of adequate targeting properties and/or to their difficulties for penetrating tumors. Here we report a multifunctional drug nanocarrier consisting of hyaluronic acid nanocapsules conjugated with the tumor homing peptide tLyp1, which exhibits both, dual targeting properties (to the tumor and to the lymphatics), and enhanced tumor penetration. Data from a 3D co-culture in vitro model showed the capacity of these nanocapsules to interact with the NRP1 receptors over-expressed in cancer cells. The targeting capacity of the nanocapsules was evidenced in orthotopic lung cancer-bearing mice, using docetaxel as a standard drug. The results showed a dramatic accumulation of docetaxel in the tumor (37-fold the one achieved with Taxotere®). This biodistribution profile correlated with the high efficacy shown in terms of tumor growth regression and drastic reduction of metastasis in the lymphatics. When efficacy was validated in a pancreatic patient-derived tumor, the nanocapsule's activity was comparable to that of a dose ten times higher of Abraxane®. Multi-functionality was found to be the key to the success of this new therapy.

GE11 peptide-conjugated nanoliposomes to enhance the combinational therapeutic efficacy of docetaxel and siRNA in laryngeal cancers

In this study, dual therapeutic-loaded GE11 peptide-conjugated liposomes were developed and applied to enhance therapeutic efficacies of standard-of-care regimens for the treatment of laryngeal cancer. The therapeutic strategy used here was a combination treatment with the chemotherapeutic docetaxel (DTX) and siRNA against the ABCG2 gene that regulates multidrug resistance in many tumor types. Liposome-encapsulated DTX/ABCG2-siRNA molecules were targeted to recognize tumor cells of squamous morphology by conjugation to the EGFR-targeting ligand, GE11. Targeted, drug-infused liposomes were nanosized and exhibited controlled release of DTX. Presence of GE11 peptides on liposomal surfaces enhanced the quantities of liposomal constructs taken up by Hep-2 laryngeal cancer cells. GE11 peptide-conjugated liposomes also enhanced cytotoxic effects against Hep-2 laryngeal cancer cells when compared to treatment with free DTX, thereby reducing IC50 values. Additionally, GE11 peptide-conjugated liposomes had significantly increased anti-tumor and apoptotic effects. Treatments with the GDSL nanoparticle formulation inhibited tumor growth in Hep-2 xenograft-bearing nude mouse models when compared to treatments with non-targeted NP constructs. Treatment of the mouse models with GE11 peptide-conjugated liposomes mitigated toxicities observed after treatment with free DTX. Taken together, liposomal encapsulation of DTX and ABCG2-siRNA improved the anti-tumor effects of treatment with free DTX in Hep-2 cell lines, and conjugation of GE11 peptides to liposomal constructs enhanced anti-tumor efficacies and specificities in laryngeal cancer cells.

Assessment of the permeability and toxicity of polymeric nanocapsules using the zebrafish model

Aim: To assess the capacity of a new drug delivery nanocapsule (NC) with a double shell of hyaluronic acid and protamine to overcome biological barriers using the zebrafish model. Materials & methods: NCs were prepared by the solvent displacement method, tagged with fluorescent makers and physicochemically characterized. Toxicity was evaluated according to the Fish Embryo Acute Toxicity test, and permeability was tested by exposing zebrafish, with and without chorion, to the fluorescent NCs. Results: Toxicity of NCs was very low as compared with that of a control nanoemulsion. Double-shell NCs were able to cross chorion and skin. Conclusion: Beyond the potential value of hyaluronic acid:protamine NCs for overcoming epithelial barriers, this works highlights the utility of zebrafish for fast screening of nanocarriers.

Preparation and characterization of surface-modified PLGA-polymeric nanoparticles used to target treatment of intestinal cancer

Docetaxel (DTX), a cytotoxic taxane, is a poor water-soluble drug and exhibits less oral bioavailability. Current research investigates the effective transport, for DTX-loaded chitosan (CS)-coated-poly-lactide-co-glycolide (PLGA)-nanoparticles (NPs) (DTX-CS-PLGA-NPs) and DTX-PLGA-NPs as well as a novel third-generation P-gp inhibitor i.e. GF120918 (Elacridar), across intestinal epithelium with its successive uptake by the tumour cells in an in vitro model. The prepared NPs showed a spherical shape particle size i.e. <123.96 nm with polydispersity index (PDI) of <0.290 whereas for CS-coated NPs, the zeta potential was converted from negative to positive value along with a small modification in particle size distribution. The entrapment efficiency observed for DTX-CS-PLGA-NPs was 74.77%, whereas the in vitro release profile revealed an initial rapid DTX release followed by a sustained release pattern. For apparent permeability, DTX-CS-PLGA-NPs and DTX-PLGA-NPs along with GF120918 showed a five-fold (p < .01) and 2.2-fold enhancement, respectively, as observed in rat ileum permeation study. Similarly, for pharmacokinetic (PK) studies, higher oral bioavailability was observed from DTX-CS-PLGA-NPs (5.11-folds) and DTX-PLGA-NPs (3.29-folds) as compared with DTX-suspension (DTX-S). Cell uptake studies on A549 cells as performed for DTX-CS-PLGA-NPs and DTX-PLGA-NPs loaded with rhodamine 123 dye, exhibited enhanced uptake as compared with plain dye solution. The enhanced uptake for DTX-CS-PLGA-NPs and DTX-PLGA-NPs formulations in the presence of GF120918 was confirmed further with the help of confocal laser scanning microscopic images (CLSM). The potential of the third-generation novel P-gp inhibitor (GF120918) investigated for the effective delivery of DTX as well as investigation of permeability and uptake studies whereby a strong potential of GF120918 for effective oral delivery was established.

Cytosolic co-delivery of miRNA-34a and docetaxel with core-shell nanocarriers via caveolae-mediated pathway for the treatment of metastatic breast cancer

Co-delivery of microRNAs and chemotherapeutic drugs into tumor cells is an attractive strategy for synergetic breast cancer therapy due to their complementary mechanisms. In this work, a core-shell nanocarrier coated by cationic albumin was developed to simultaneously deliver miRNA-34a and docetaxel (DTX) into breast cancer cells for improved therapeutic effect. The co-delivery nanocarriers showed a spherical morphology with an average particle size of 183.9 nm, and they efficiently protected miRNA-34a from degradation by RNase and serum. Importantly, the nanocarriers entered the cytosol via a caveolae-mediated pathway without entrapment in endosomes/lysosomes, thus improving the utilization of the cargo. In vitro, the co-delivery nanocarriers suppressed the expression of anti-apoptosis gene Bcl-2 at both transcription and protein levels, inhibited tumor cell migration and efficiently induced cell apoptosis and cytotoxicity. In vivo, the co-delivery nanocarriers prolonged the blood circulation of DTX, enhanced tumor accumulation of the cargo and significantly inhibited tumor growth and metastasis in 4T1-tumor bearing mice models. Taken together, the present nanocarrier co-loading with DTX and miRNA-34a is a new nanoplatform for the combination of insoluble drugs and gene/protein drugs and provides a promising strategy for the treatment of metastatic breast cancer.

Biomaterials to suppress cancer stem cells and disrupt their tumoral niche

Lack of improvement in the treatment options of several types of cancer can largely be attributed to the presence of a subpopulation of cancer cells with stem cell signatures and to the tumoral niche that supports and protects these cells. This review analyses the main strategies that specifically modulate or suppress cancer stem cells (CSCs) and the tumoral niche (TN), focusing on the role of biomaterials (i.e. implants, nanomedicines, etc.) in these therapies. In the case of CSCs, we discuss differentiation therapies and the disruption of critical cellular signaling networks. For the TN, we analyze diverse strategies to modulate tumor hypervascularization and hypoxia, tumor extracellular matrix, and the inflammatory and tumor immunosuppressive environment. Due to their capacity to control drug disposition and integrate diverse functionalities, biomaterial-based therapies can provide important benefits in these strategies. We illustrate this by providing case studies where biomaterial-based therapies either show CSC suppression and TN disruption or improved delivery of major modulators of these features. Finally, we discuss the future of these technologies in the framework of these emerging therapeutic concepts.