Novel polymeric nanoparticles for intracellular delivery of peptide Cargos: antitumor efficacy of the BCL-2 conversion peptide NuBCP-9

Small Molecule Functional Converter of B-Cell Lymphoma-2 (Bcl-2) Suppresses Breast Cancer Lung Metastasis

The B-cell lymphoma-2 (Bcl-2) family of proteins plays a vital role in tumorigenesis. Cancer cells utilize the expression of Bcl-2 to evade therapy and develop resistance. Bcl-2 overexpression also causes cancer cells to be more invasive and metastatic. About 80% of cancer deaths are due to metastases, and yet targeted therapies for metastatic cancers are scarce. We discovered a small molecule, BFC1103, which changes the conformation of Bcl-2 to convert the antiapoptotic protein to a proapoptotic protein. BFC1103-induced apoptosis is dependent on the expression levels of Bcl-2, with higher levels causing more apoptosis. BFC1103 suppressed the growth of breast cancer lung metastasis. BFC1103 has the potential for further optimization and development for clinical testing in metastatic cancers that express Bcl-2. This study demonstrates a new approach to target Bcl-2 using a small molecule, BFC1103, to suppress metastatic disease.

Identification and Characterization of a Small Molecule Bcl-2 Functional Converter

Cancer cells exploit the expression of anti-apoptotic protein Bcl-2 to evade apoptosis and develop resistance to therapeutics. High levels of Bcl-2 leads to sequestration of pro-apoptotic proteins causing the apoptotic machinery to halt. In this study, we report discovery of a small molecule, BFC1108 (5-chloro-N-(2-ethoxyphenyl)-2-[(4-methoxybenzyol)amino]benzamide), which targets Bcl-2 and converts it into a pro-apoptotic protein. The apoptotic effect of BFC1108 is not inhibited, but rather potentiated, by Bcl-2 overexpression. BFC1108 induces a conformational change in Bcl-2, resulting in the exposure of its BH3 domain both in vitro and in vivo. BFC1108 suppresses the growth of triple-negative breast cancer xenografts with high Bcl-2 expression and inhibits breast cancer lung metastasis. This study demonstrates a novel approach to targeting Bcl-2 using BFC1108, a small molecule Bcl-2 functional converter that effectively induces apoptosis in Bcl-2-expressing cancers.

SIGNIFICANCE

We report the identification of a small molecule that exposes the Bcl-2 killer conformation and induces death in Bcl-2-expressing cancer cells. Selective targeting of Bcl-2 and elimination of cancer cells expressing Bcl-2 opens up new therapeutic avenues.

Mathematical modelling of microneedle-mediated transdermal delivery of drug nanocarriers into skin tissue and circulatory system

Microneedle-mediated transdermal delivery using nanocarriers can successfully overcome the barrier of the stratum corneum and protect drugs from elimination in skin tissues. However, the effectiveness of drug delivery to different layers of skin tissues and the circulatory system varies considerably, subject to the properties of the drug delivery system and delivery regime. How to maximise delivery outcomes remains unclear. In this study, mathematical modelling is employed to investigate this transdermal delivery under various conditions, using the skin model that is reconstructed based on the realistic skin anatomical structure. Treatment efficacy is evaluated in terms of drug exposure over time. The modelling results demonstrate the complex dependence of drug accumulation and distribution on the nanocarrier properties, microneedle properties and environment in different skin layers and blood. Specifically, delivery outcomes in the entire skin and blood can be improved by increasing the loading dose and reducing microneedle spacing. However, several parameters need to be optimised with respect to the specific location of the target site in the tissue for better treatment; these include the drug release rate, nanocarrier diffusivity in microneedle and skin tissue, nanocarrier transvascular permeability, nanocarrier partition coefficient between tissue and microneedle, microneedle length, wind speed and relative humidity. The delivery is less sensitive to the diffusivity and physical degradation rate of free drugs in microneedle, and their partition coefficient between tissue and microneedle. Results obtained from this study can be used to improve the design of the microneedle-nanocarrier combined drug delivery system and delivery regime.

Structure of polymeric nanoparticles encapsulating a drug - pamoic acid ion pair by scanning transmission electron microscopy

Drug-delivery systems based on polymeric nanoparticles are useful for improving drug bioavailability and/or delivery of the active ingredient for example directly to the cancerous tumour. The physical and chemical characterization of a functionalized nanoparticle system is required to measure drug loading and dispersion but also to understand and model the rate and extent of drug release to help predict performance. Many techniques can be used, however, difficulties related to structure determination and identifying the precise location of the drug fraction make mathematical prediction complex and in many published examples the final conclusions are based on assumptions regarding an expected structure. Cryogenic scanning transmission electron microscopy imaging in combination with electron energy loss spectroscopy techniques are used here to address this issue and provide a multi-modal approach to the characterisation of a self-assembled polymeric nanoparticle system based upon a polylactic acid - polyethylene glycol (PLA-PEG) block copolymer containing a hydrophobic ion-pair between pamoic acid and an active pharmaceutical ingredient (API). Results indicate a regular dispersion of spherical nanoparticles of 88 ± 9 nm diameter. The particles are shown to have a multi-layer structure consisting of a 25 nm radius hydrophobic core of PLA and pamoic acid-API material with additional enrichment of the pamoic acid-API material within the inner core (that can be off-centre), surrounded by a 9 nm dense PLA-PEG layer all with a low-density PEG surface coating of around 10 nm thickness. This structure suggests that release of the API can only occur by diffusion through or degradation of the dense, 9 nm thick PLA-PEG layer either of which is a process consistent with the previously reported steady release kinetics of the API and counter ion from these nanoparticle formulations. Establishing accurate measures of product structure enables a link to performance by providing appropriate physical parameters for future mathematical modelling of barriers controlling API release in these nanoparticle formulations.

Mst1-mediated phosphorylation of Nur77 improves the endometrial receptivity in human and mice

BACKGROUND

Successful embryo implantation requires the attachment of a blastocyst to the receptive endometrial epithelium, which was disturbed in the women with recurrent implantation failure (RIF). Endometrial β3-integrin was the most important adhesion molecule contributing to endometrial receptivity in both humans and mice. Nur77 has been proven indispensable for fertility in mice, here we explore the role of Nur77 on embryo-epithelial adhesion and potential treatment to embryo implantation failure.

METHODS

The expression and location of Mst1 and Nur77 in endometrium from fertile women and RIF patients were examined by IHC, qRT-PCR and Western blotting. In vitro kinase assay following with LC-MS/MS were used to identify the phosphorylation site of Nur77 activated by Mst1. The phosphorylated Nur77 was detected by phos-tag SDS-PAGE assay and specific antibody against phospho-Nur77-Thr366. The effect of embryo-epithelium interaction was determined in the BeWo spheroid or mouse embryo adhesion assay, and delayed implantation mouse model. RNA-seq was used to explore the mechanism by which Nur77 derived peptide promotes endometrial receptivity.

FINDINGS

Endometrial Mammalian sterile 20 (STE20)-like kinase 1 (Mst1) expression level was decreased in the women with RIF than that in the fertile control group, while Mst1 activation in the epithelial cells promoted trophoblast-uterine epithelium adhesion. The effect of Nur77 mediated trophoblast-uterine epithelium adhesion was facilitated by active Mst1. Mechanistically, mst1 promotes the transcription activity of Nur77 by phosphorylating Nur77 at threonine 366 (T366), and consequently increased downstream target β3-integrin expression. Furthermore, a Nur77-derived peptide containing phosphorylated T366 markedly promoted mouse embryo attachment to Ishikawa cells ([4 (2-4)] vs [3 (2-4)]) and increased the embryo implantation rate (4 vs 1.4) in a delayed implantation mouse model by regulating integrin signalling. Finally, it is observed that the endometrial phospho-Nur77 (T366) level is decreased by 80% in the women with RIF.

INTERPRETATION

In addition to uncovering a potential regulatory mechanism of Mst1/Nur77/β3-integrin signal axis involved in the regulation of embryo-epithelium interaction, our finding provides a novel marker of endometrial receptivity and a potential therapeutic agent for embryo implantation failure.

FUNDING

National Key Research and Development Program of China (2018YFC1004400), the National Natural Science Foundation of China (82171653, 82271698, 82030040, 81971387 and 30900727), and National Institutes of Health grants (R01HL103869).

Nanocarrier system: An emerging strategy for bioactive peptide delivery

Compared with small-molecule synthetic drugs, bioactive peptides have desirable advantages in efficiency, selectivity, safety, tolerance, and side effects, which are accepted by attracting extensive attention from researchers in food, medicine, and other fields. However, unacceptable barriers, including mucus barrier, digestive enzyme barrier, and epithelial barrier, cause the weakening or the loss of bioavailability and biostability of bioactive peptides. The nanocarrier system for bioactive peptide delivery needs to be further probed. We provide a comprehensive update on the application of versatile delivery systems for embedding bioactive peptides, including liposomes, polymer nanoparticles, polysaccharides, hydrogels, and self-emulsifying delivery systems, and further clarify their structural characterization, advantages, and disadvantages as delivery systems. It aims to provide a reference for the maximum utilization of bioactive peptides. It is expected to be an effective strategy for improving the bioavailability and biostability of bioactive peptides.

Quatramer™ Mediated Codelivery of PI3-Kδ/HDAC6 Dual Inhibitor Augments the Anti-Cancer Efficacy of Epirubicin in Breast Cancer

The disruption and overexpression of phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway in cancer results in tumor growth, metastasis, and survival. Treatment with common anthracyclines has confirmed cancer cells' dependence on PI3K pathway through overexpression of AKT. Moreover, combining HDAC inhibitor with anthracycline has shown the targeting of breast cancer stem cells. Therefore, it has been hypothesized that the co-delivery of PI3-Kδ/HDAC6 dual inhibitor with Epirubicin using polymeric nanoparticle could increase the anti-cancer treatment efficacy with reduced toxicity. Pluronic modified polylactic acid block copolymer (quatramer) was used for encapsulation of PI3-Kδ/HDAC6 and Epirubicin. The co-encapsulated nanoparticles, PI3-Kδ/HDAC6-Epi-NPs have shown size of 99±3 nm, PDI of 0.18±0.07 with a sustained and slow-release profile in non-physiological buffer (PBS, pH 7.4). The in-vitro cell proliferation inhibition studies done on 2D and 3D culture of breast cancer cell lines have confirmed the synergistic effect of PI3-Kδ/HDAC6-Epi-NPs with lower IC₅₀ values compared to PI3-Kδ/HDAC6-NPs and Epi-NPs. Additionally, intravenous twice a week treatment for three weeks with PI3-Kδ/HDAC6-Epi-NPs resulted in complete tumor eradication in the syngeneic breast tumor mice model. In comparison, the PI3-Kδ/HDAC6-NPs and Epi-NPs result in tumor growth inhibition of 15.86% and 81.59%, respectively. These studies predicted that clinical use of PI3-Kδ/HDAC6-Epi-NPs will be effective in breast cancer treatments.

Anticancer Biosurfactant-Loaded PLA-PEG Nanoparticles Induce Apoptosis in Human MDA-MB-231 Breast Cancer Cells

Despite various advancements in cancer therapies, treating cancer efficiently without side effects is still a major concern for researchers. Anticancer drugs from natural sources need to be explored as a replacement for chemo drugs to overcome their limitations. In our previous studies, isolation, characterization, and anticancer properties of a novel biosurfactant from Candida parapsilosis were reported. In this study, we report the cytotoxicity of the polymeric nanoparticles of this novel biosurfactant toward breast cancer cells. Biosurfactant-encapsulated polymeric nanoparticles of polylactic acid-poly(ethylene glycol) (PLA-PEG) copolymers were synthesized by the double emulsion solvent evaporation method. Folic acid (FA) was used as a targeting ligand to actively deliver the anticancer cargo to the cancer site. The encapsulation efficiency of nanoparticles was observed as 84.9%, and Fickian diffusion was observed as a kinetic model for the release of biosurfactant from nanoparticles. The controlled delivery of the biosurfactant was noticed when encapsulated in PLA-PEG copolymer nanoparticles. Additionally, it was observed that FA enhanced the uptake and cytotoxicity of biosurfactant-loaded nanoparticles in MDA-MB-231 cancer cells compared to biosurfactant-loaded plain nanoparticles. Induction of apoptosis was observed in cancer cells by these nanoparticles. We explore a potential anticancer agent that can be further analyzed for its efficiency and can be used as an alternative tool.

Emerging uses of PLA-PEG copolymer in cancer drug delivery

Traditional therapies need high systematic dosages that not only destroys cancerous cells but also healthy cells. To overcome this problem recent advancement in nanotechnology specifically in nanomaterials has been extensively done for various biological applications, such as targeted drug delivery. Nanotechnology, as a frontier science, has the potential to break down all the obstacles to be more effective and secure drug delivery system. It is possible to develop nanopolymer based drug carrier that can target drugs with extreme accuracy. Polymers can advance drug delivery technologies by allowing controlled release of therapeutic drugs in stable amounts over long duration of time. For controlled drug delivery, biodegradable synthetic polymers have various benefits over non-biodegradable polymers. Biodegradable polymer either are less toxic or non-toxic. Polylactic Acid (PLA) is one of the most remarkable amphipathic polymers which make it one of the most suitable materials for polymeric micelles. Amphiphilic nanomaterial, such as Polyethylene Glycol (PEG), is one of the most promising carrier for tumor targeting. PLA-PEG as a copolymer has been generally utilized as drug delivery system for the various types of cancer. Chemotherapeutic drugs are stacked into PLA-PEG copolymer and as a result their duration time delays, hence medications arrive at specific tumor site.

Oxidative stress in obesity-associated hepatocellular carcinoma: sources, signaling and therapeutic challenges

Obesity affects more than 650 million individuals worldwide and is a well-established risk factor for the development of hepatocellular carcinoma (HCC). Oxidative stress can be considered as a bona fide tumor promoter, contributing to the initiation and progression of liver cancer. Indeed, one of the key events involved in HCC progression is excessive levels of reactive oxygen species (ROS) resulting from the fatty acid influx and chronic inflammation. This review provides insights into the different intracellular sources of obesity-induced ROS and molecular mechanisms responsible for hepatic tumorigenesis. In addition, we highlight recent findings pointing to the role of the dysregulated activity of BCL-2 proteins and protein tyrosine phosphatases (PTPs) in the generation of hepatic oxidative stress and ROS-mediated dysfunctional signaling, respectively. Finally, we discuss the potential and challenges of novel nanotechnology strategies to prevent ROS formation in obesity-associated HCC.

Advanced nanomedicine and cancer: Challenges and opportunities in clinical translation

Cancer has reached pandemic dimensions in the whole world. Although current medicine offers multiple treatment options against cancer, novel therapeutic strategies are needed due to the low specificity of chemotherapeutic drugs, undesired side effects and the presence of different incurable types of cancer. Among these new strategies, nanomedicine arises as an encouraging approach towards personalized medicine with high potential for present and future cancer patients. Therefore, nanomedicine aims to develop novel tools with wide potential in cancer treatment, imaging or even theranostic purposes. Even though numerous preclinical studies have been published with successful preliminary results, promising nanosystems have to face multiple obstacles before adoption in clinical practice as safe options for patients with cancer. In this MiniReview, we provide a short overview on the latest advances in current nanomedicine approaches, challenges and promising strategies towards more accurate cancer treatment.

Use of anticancer peptides as an alternative approach for targeted therapy in breast cancer: a review

Breast cancer is the most common cancer in women worldwide. Traditional therapies are expensive and cause severe side effects. Targeted therapy is a powerful method to circumvent the problems of other therapies. It also allows drugs to localize at predefined targets in a selective manner. Currently, there are several monoclonal antibodies which target breast cancer cell surface markers. However, using antibodies has some limitations. In the last two decades, many investigators have discovered peptides that may be useful to target breast cancer cells. In this article, we provide an overview on anti-breast cancer peptides, their sources and biological activities. We further discuss the pros and cons of using anticancer peptides with further emphasis on how to improve their effectiveness in cancer therapy.

Integration of Dual Targeting and Dual Therapeutic Modules Endows Self-Assembled Nanoparticles with Anti-Tumor Growth and Metastasis Functions

OBJECT

High targeting and efficient cytotoxicity toward tumor cells endow NPs excellent anti-tumor activity. Herein, a peptide polymer possessing dual-targeting ability and double therapeutic activity was developed and named TGMF, which can form NPs through self-assembly. It is composed of four functional modules: 1) Active targeting peptide TMTP1 (T) deliver NPs to tumors specifically; 2) Therapeutic peptide GO-203 (G), which can significantly inhibit tumor growth by disrupting the redox balance in cells; 3) A passively targeted enzyme-responsive peptide PLGLGA (M), which can be cleaved specifically by metalloproteinase-2 (MMP-2) highly expressed in the tumor microenvironment (TME); and 4) Hexadecyl (F), which has strong hydrophobicity, can promote the self-assembly of TGMF NPs.

METHODS

Five modular peptide probes, namely, TGF, TMF, TGM, GMF, and TGMF were synthesized and self-assembled into NPs in solution. The characterization, enzyme reactivity, and cytotoxicity of NPs were evaluated in vitro, and the pharmacokinetics, bio-distribution, anti-tumor activity of NPs were investigated in vivo. In addition, transcriptome sequencing identified the intracellular signaling pathway-related genes involved in the anti-tumor effect of TGMF.

RESULTS

Upon enzyme cleavage, two types of nanostructure, NPs and nanofibers (NFs), were detected under TEM. Moreover, the cytotoxicity and anti-invasion activity of TGMF against tumor cells used were strongest among the five modular probes examined in vitro. TGMF increased reactive oxygen species (ROS) levels in cytoplasm and produced numerous NFs in extracellular interval and intracellular space. Transcriptome sequencing revealed that TGMF caused 446 genes' down-regulation and 270 genes' up-regulation in HeLa cells. In vivo, TGMF has a good anti-tumor effect, effectively prolonging the survival time of HeLa-tumor-bearing mice without systemic side effects.

CONCLUSION

Integration of multiple functional modules into NPs could be a promising strategy for the future of nanomedicine design towards tumor treatment.

Anticancer Mechanisms of Bioactive Peptides

Despite technological advancement, there is no 100% effective treatment against metastatic cancer. Increasing resistance of cancer cells towards chemotherapeutic drugs along with detrimental side effects remained a concern. Thus, the urgency in developing new anticancer agents has been raised. Anticancer peptides have been proven to display potent activity against a wide variety of cancer cells. Several mode of actions describing their cytostatic and cytotoxic effect on cancer cells have been proposed which involves cell surface binding leading to membranolysis or internalization to reach their intracellular target. Understanding the mechanism of action of these anticancer peptides is important in achieving full therapeutic success. In the present article, we discuss the anticancer action of peptides accompanied by the mechanisms underpinning their toxicity to cancer cells.

Multivalent dextran hybrids for efficient cytosolic delivery of biomolecular cargoes

The development of novel biotherapeutics based on peptides and proteins is often limited to extracellular targets, because these molecules are not able to reach the cytosol. In recent years, several approaches were proposed to overcome this limitation. A plethora of cell-penetrating peptides (CPPs) was developed for cytoplasmic delivery of cell-impermeable cargo molecules. For many CPPs, multimerization or multicopy arrangement on a scaffold resulted in improved delivery but also higher cytotoxicity. Recently, we introduced dextran as multivalent, hydrophilic polysaccharide scaffold for multimerization of cell-targeting cargoes. Here, we investigated covalent conjugation of a CPP to dextran in multiple copies and assessed the ability of resulted molecular hybrid to enter the cytoplasm of mammalian cells without largely compromising cell viability. As a CPP, we used a novel, low-toxic cationic amphiphilic peptide L17E derived from M-lycotoxin. Here, we show that cell-penetrating properties of L17E are retained upon multivalent covalent linkage to dextran. Dextran-L17E efficiently mediated cytoplasmic translocation of an attached functional peptide and a peptide nucleic acid (PNA). Moreover, a synthetic route was established to mask the lysine side chains of L17E with a photolabile protecting group thus opening avenues for light-triggered activation of cellular uptake.

Evaluation of In Vivo toxicity of Novel Biosurfactant from Candida parapsilosis loaded in PLA-PEG Polymeric Nanoparticles

The aim of this study was to evaluate the toxicological profile of biosurfactant encapsulated polymeric nanoparticles of Polylactic acid-Polyethylene glycol (PLA-PEG) in mice. Hematological, biochemical and histopathological samples of rodents were evaluated. Mice were selected randomly and divided into 3 treatment groups and one control group. Group I mice served as a control group, Group II were administrated with biosurfactant, Group III were treated with Polymeric nanoparticles of PLA-PEG. Group IV mice were injected with biosurfactant loaded polymeric nanoparticles of PLA-PEG. The formulations were administered intravenously via tail vein with 20 μg/mL dose concentration of biosurfactant. The normal control group was injected with only PBS. Blood samples were collected on 7th, 14th and 21st day and hematological and biochemical assays were performed. After the blood collection, mice were sacrificed for histopathological examination. The results showed that there were no significant difference in hematology parameter between the control and treated group. Some minute, non-significant changes were found in biochemical parameters which were not considered. Histopathological result of selected vital organs revealed that the biosurfactant and/or PLA-PEG polymeric nanoparticles can be considered as safe as no toxicological features were observed in histopathology of tissues. Hence, it can be deliberated that the biosurfactant encapsulated in PLA-PEG copolymeric nanoparticles are non toxic and can provide a safe, suitable platform for biomedical applications in future.

Interplay between orphan nuclear receptors and androgen receptor-dependent or-independent growth signalings in prostate cancer

It is well-established that both the initial and advanced growth of prostate cancer depends critically on androgens and thus on the activated androgen receptor (AR) -mediated signaling pathway. The unique hormone-dependent feature of prostate cancer forms the biological basis of hormone or androgen-deprivation therapy (ADT) that aims to suppress the AR signaling by androgen depletion or AR antagonists. ADT still remains the mainstay treatment option for locally advanced or metastatic prostate cancer. However, most patients upon ADT will inevitably develop therapy-resistance and progress to relapse in the form of castration-resistant disease (castration-resistant prostate cancer or CRPC) or even a more aggressive androgen-independent subtype (therapy-related neuroendocrine prostate cancer or NEPC). Recent advances show that besides AR, some ligand-independent members of nuclear receptor superfamily-designated as orphan nuclear receptors (ONRs), as their endogenous physiological ligands are either absent or not yet identified to date, also play significant roles in the growth regulation of prostate cancer via multiple AR-dependent or -independent (AR-bypass) pathways or mechanisms. In this review, we summarize the recent progress in the newly elucidated roles of ONRs in prostate cancer, with a focus on their interplay in the AR-dependent pathways (intratumoral androgen biosynthesis and suppression of AR signaling) and AR-independent pathways or cellular processes (hypoxia, oncogene- or tumor suppressor-induced senescence, apoptosis and regulation of prostate cancer stem cells). These ONRs with their newly characterized roles not only can serve as novel biomarkers but also as potential therapeutic targets for management of advanced prostate cancer.

Improved in vivo targeting of BCL-2 phenotypic conversion through hollow gold nanoshell delivery

Although new cancer therapeutics are discovered at a rapid pace, lack of effective means of delivery and cancer chemoresistance thwart many of the promising therapeutics. We demonstrate a method that confronts both of these issues with the light-activated delivery of a Bcl-2 functional converting peptide, NuBCP-9, using hollow gold nanoshells. This approach has shown not only to increase the efficacy of the peptide 30-fold in vitro but also has shown to reduce paclitaxel resistant H460 lung xenograft tumor growth by 56.4%.

Present Scenario of Bioconjugates in Cancer Therapy: A Review

Cancer is one of the deadliest diseases and poses a risk to people all over the world. Surgery, chemo, and radiation therapy have been the only options available until today to combat this major problem. Chemotherapeutic drugs have been used for treatment for more than 50 years. Unfortunately, these drugs have inherent cytotoxicities and tumor cells have started inducing resistance against these drugs. Other common techniques such as surgery and radiotherapy have their own drawbacks. Therefore, such techniques are incompetent tools to alleviate the disease efficiently without any adverse effects. This scenario has inspired researchers to develop alternative techniques with enhanced therapeutic effects and minimal side effects. Such techniques include targeted therapy, liposomal therapy, hormonal therapy, and immunotherapy, etc. However, these therapies are expensive and not effective enough. Furthermore, researchers have conjugated therapeutic agents or drugs with different molecules, delivery vectors, and/or imaging modalities to combat such problems and enhance the therapeutic effect. This conjugation technique has led to the development of bioconjugation therapy, in which at least one molecule is of biological origin. These bioconjugates are the new therapeutic strategies, having prospective synergistic antitumor effects and have potency to overcome the complications being produced by chemo drugs. Herein, we provide an overview of various bioconjugates developed so far, as well as their classification, characteristics, and targeting approach for cancer. Additionally, the most popular nanostructures based on their organic or inorganic origin (metallic, magnetic, polymeric nanoparticles, dendrimers, and silica nanoparticles) characterized as nanocarriers are also discussed. Moreover, we hope that this review will provide inspiration for researchers to develop better bioconjugates as therapeutic agents.

Macroporous organosilicon nanocomposites co-deliver Bcl2-converting peptide and chemotherapeutic agent for synergistic treatment against multidrug resistant cancer

Therapeutic biomacromolecules are confronted with in vivo challenges of low bio-stability and poor tumor tissue-penetration. Herein, we report for the first time, our development and characterization of a hybrid nanocomposite for delivering a Bcl-2-converting peptide (NuBCP9, N9 hereafter) and testing its efficacy alone or together with doxorubicin (DOX). The hybrid nanocomposite is composed of the internal large pore sized-mesoporous silica nanoparticles (MSNs) and the external highly-branched polyamidoamine (PAMAM) dendrimers, into which N9 peptide and DOX were encapsulated for the different sub-cellular delivery to treat drug-resistant cancer. The nanocomposite possessed the particle and pore sizes of ~37 nm and ~8 nm, which displayed the superior tumor penetration capacity over naked MSNs both in cultured-3D tumor sphere and in live animal models. Moreover, the dual drug nanocomposite exhibited a great synergistic anticancer effect on Bcl-2-positive cancer cells in vitro and animals with the negligible toxic side effects. The tumor inhibition rate of the nanocomposite (89%) was five times as much as the two drugs combination. This design provides a new effective, safe and versatile strategy to fabricate large pore-sized MSNs with the organic-inorganic hybrid framework to concurrently transport therapeutic peptides and chemotherapeutics to the specific sub-cellular locations for the synergistic cancer therapy and drug resistance reversal, which has significant impact on the development of improved cancer therapeutics.

Delivering Combination Chemotherapies and Targeting Oncogenic Pathways via Polymeric Drug Delivery Systems

The side-effects associated with chemotherapy necessitates better delivery of chemotherapeutics to the tumor. Nanoparticles can load higher amounts of drug and improve delivery to tumors, increasing the efficacy of treatment. Polymeric nanoparticles, in particular, have been used extensively for chemotherapeutic delivery. This review describes the efforts made to deliver combination chemotherapies and inhibit oncogenic pathways using polymeric drug delivery systems. Combinations of chemotherapeutics with other drugs or small interfering RNA (siRNA) combinations have been summarized. Special attention is given to the delivery of drug combinations that involve either paclitaxel or doxorubicin, two popular chemotherapeutics in clinic. Attempts to inhibit specific pathways for oncotherapy have also been described. These include inhibition of oncogenic pathways (including those involving HER2, EGFR, MAPK, PI3K/Akt, STAT3, and HIF-1α), augmentation of apoptosis by inhibiting anti-apoptosis proteins (Bcl-2, Bcl-xL, and survivin), and targeting dysregulated pathways such as Wnt/β-catenin and Hedgehog.

Tertiary Structural Motif Sequence Statistics Enable Facile Prediction and Design of Peptides that Bind Anti-apoptotic Bfl-1 and Mcl-1

Understanding the relationship between protein sequence and structure well enough to design new proteins with desired functions is a longstanding goal in protein science. Here, we show that recurring tertiary structural motifs (TERMs) in the PDB provide rich information for protein-peptide interaction prediction and design. TERM statistics can be used to predict peptide binding energies for Bcl-2 family proteins as accurately as widely used structure-based tools. Furthermore, design using TERM energies (dTERMen) rapidly and reliably generates high-affinity peptide binders of anti-apoptotic proteins Bfl-1 and Mcl-1 with just 15%-38% sequence identity to any known native Bcl-2 family protein ligand. High-resolution structures of four designed peptides bound to their targets provide opportunities to analyze the strengths and limitations of the computational design method. Our results support dTERMen as a powerful approach that can complement existing tools for protein engineering.

BI1071, a Novel Nur77 Modulator, Induces Apoptosis of Cancer Cells by Activating the Nur77-Bcl-2 Apoptotic Pathway

Nur77 (also called TR3 or NGFI-B), an orphan member of the nuclear receptor superfamily, induces apoptosis by translocating to mitochondria where it interacts with Bcl-2 to convert Bcl-2 from an antiapoptotic to a pro-apoptotic molecule. Nur77 posttranslational modification such as phosphorylation has been shown to induce Nur77 translocation from the nucleus to mitochondria. However, small molecules that can bind directly to Nur77 to trigger its mitochondrial localization and Bcl-2 interaction remain to be explored. Here, we report our identification and characterization of DIM-C-pPhCF₃ ⁺MeSO₃ ^- (BI1071), an oxidized product derived from indole-3-carbinol metabolite, as a modulator of the Nur77-Bcl-2 apoptotic pathway. BI1071 binds Nur77 with high affinity, promotes Nur77 mitochondrial targeting and interaction with Bcl-2, and effectively induces apoptosis of cancer cells in a Nur77- and Bcl-2-dependent manner. Studies with animal model showed that BI1071 potently inhibited the growth of tumor cells in animals through its induction of apoptosis. Our results identify BI1071 as a novel Nur77-binding modulator of the Nur77-Bcl-2 apoptotic pathway, which may serve as a promising lead for treating cancers with overexpression of Bcl-2.

Targeted and Sustained Corelease of Chemotherapeutics and Gene by Injectable Supramolecular Hydrogel for Drug-Resistant Cancer Therapy

Coadministration of chemotherapeutics as well as therapeutic gene could play a synergistic effect on cancer treatment. It is noteworthy that targeted and sustained codelivery of chemotherapeutic and therapeutic gene was rarely achieved in previous reports, while it might serve as an important platform for treating solid tumor with possible surrounding lesions. Herein, an injectable supramolecular hydrogel formed by α-cyclodextrin (α-CD) and cationic amphiphilic copolymer made of methoxy-poly(ethylene glycol)-b-poly(ε-caprolactone)-b-poly(ethylene imine) with folic acid targeted group (MPEG-PCL-PEI-FA), is rationally designed to achieve sustained codelivery of chemotherapeutic paclitaxel (PTX) and B-cell lymphoma-2 (Bcl-2) conversion gene Nur77 in the form of nanocomplex up to 7 days, to effectively inhibit the growth of folate receptor overexpressing H460/Bcl-2 therapeutic-resistant tumors (induced by overexpression of anti-apoptotic Bcl-2 protein), with peritumoral injection rather than direct intratumoral injection of hydrogel. To the best of our knowledge, this is a pioneer report on injectable MPEG-PCL-PEI-FA/α-CD supramolecular hydrogel with the ability to codeliver and sustainedly release PTX and Nur77 gene to combat Bcl-2 overexpressed therapeutic-resistant tumors in a targeted manner, which might be beneficial for further design in personalized medicine.

Biodegradable Polymeric Nanoparticles for Therapeutic Cancer Treatments

Polymeric nanoparticles have tremendous potential to improve the efficacy of therapeutic cancer treatments by facilitating targeted delivery to a desired site. The physical and chemical properties of polymers can be tuned to accomplish delivery across the multiple biological barriers required to reach diverse subsets of cells. The use of biodegradable polymers as nanocarriers is especially attractive, as these materials can be designed to break down in physiological conditions and engineered to exhibit triggered functionality when at a particular location or activated by an external source. We present how biodegradable polymers can be engineered as drug delivery systems to target the tumor microenvironment in multiple ways. These nanomedicines can target cancer cells directly, the blood vessels that supply the nutrients and oxygen that support tumor growth, and immune cells to promote anticancer immunotherapy.

Concomitant Delivery of Paclitaxel and NuBCP-9 peptide for synergistic enhancement of cancer therapy

Paclitaxel (PTX) is a microtubule inhibitor administered as an albumin-bound nanoformulation for the treatment of breast cancer. However, the effectiveness of PTX is limited by resistance mechanisms mediated in part by upregulation of the anti-apoptotic BCL-2 and P-glycoprotein (P-gp). Present investigation was designed to study the synergistic potential of NuBCP-9 and PTX loaded polymeric nanoparticles to minimize the dose and improve the efficacy and safety. PTX and NuBCP-9 loaded polylactic acid-polyethylene glycol-polypropylene glycol-polyethylene glycol [PLA-(PEG-PPG-PEG)] nanoparticles were prepared by double emulsion solvent evaporation method. PTX and NuBCP-9 loaded NPs displayed an average size of 90 nm with spherical morphology. PTX and NuBCP-9 dual loaded NPs reducedIC50 by ~40-fold and acted synergistically. Treatment of the syngeneic EAT mice with PTX-NuBCP-9/NPs resulted in improved efficacy than that alone treated mice. Overall, the concomitant delivery PTX and NuBCP-9 loaded NPs showed superior activity than that of PTX and NuBCP-9 alone treated mice.

Pro-apoptotic peptides-based cancer therapies: challenges and strategies to enhance therapeutic efficacy

Cancer is a leading cause of death worldwide. Despite many advances in the field of cancer therapy, an effective cure is yet to be found. As a more potent alternative for the conventional small molecule anti-cancer drugs, pro-apoptotic peptides have emerged as a new class of anticancer agents. By interaction with certain members in the apoptotic pathways, they could effectively kill tumor cells. However, there remain bottleneck challenges for clinical application of these pro-apoptotic peptides in cancer therapy. In this review, we will overview the developed pro-apoptotic peptides and outline the widely adopted molecular-based and nanoparticle-based strategies to enhance their anti-tumor effects.

Induction of apoptosis and suppression of tumor growth by Nur77-derived Bcl-2 converting peptide in chemoresistant lung cancer cells

Resistance to chemotherapy is a major cause of treatment failure and poor overall survival in patients with lung cancer. Identification of molecular targets present in resistant cancer cells is essential for addressing therapeutic resistance and prolonging lung cancer patient survival. Members of the B-cell lymphoma 2 (Bcl-2) family of proteins are associated with chemotherapeutic resistance. In this study, we found that pro-survival protein Bcl-2 is upregulated in paclitaxel resistant cells, potentially contributing to chemotherapy resistance. To exploit the increase in Bcl-2 expression for targeting therapy resistance, we investigated the effects of a peptide derived from the nuclear receptor Nur77 that converts Bcl-2 from an anti-apoptotic protein to a pro-apoptotic protein. The Nur77 derived peptide preferentially induced apoptosis in paclitaxel-resistant cancer cells with high expression of Bcl-2. This peptide also induced apoptosis of multidrug resistant H69AR lung cancer cells that express Bcl-2 and inhibited their growth in 3D spheroids. The Nur77 peptide strongly suppressed the growth of paclitaxel-resistant lung cancer cells in a zebrafish xenograft tumor model. Taken together, our data supports a new strategy for treating lung cancers that acquire resistance to chemotherapy through overexpression of Bcl-2.

Molecular Features Influencing the Release of Peptides from Amphiphilic Polymeric Reverse Micelles

Efficient and controlled release of peptides bound to polymeric reverse micelle assemblies can be achieved through the cooperative effects of disassembly and disruption of charge-charge interactions. Through the examination of various peptides and polymer architectures, we have identified the factors that affect the release efficiency of the electrostatically bound peptides. Peptide guests and polymers with a greater number of complementary charges result in less efficient release than peptides and polymers with lower numbers of charges. Interestingly, we find that the presence of adjacent charged groups on the monomeric unit of the polymer exhibits exceptionally low release efficiency, perhaps because of a chelate-like effect, even when the total polymer charge is lower. Overall, our findings inform the design principles for catch-and-release systems based on polymeric reverse micelles, which offer great versatility and tunability.

In vivo efficacy and pharmacokinetics of bi-aryl oxazolidinone RBx 11760 loaded polylactic acid-polyethylene glycol nanoparticles in mouse hematogenous bronchopneumonia and rat groin abscess caused by Staphylococcus aureus

RBx 11760 is a bi-aryl oxazolidinone antibacterial agent active against Staphylococcus aureus but has poor solubility. Here we have encapsulated RBx 11760 in PLA-PEG NPs with an aim to improve physicochemical, pharmacokinetics and in vivo efficacy. The average size and zeta potential of RBx 11760 loaded NPs were found to be 106.4 nm and -22.2 mV, respectively. The absolute size of nanoparticles by HRTEM was found to be approximately 80 nm. In vitro antibacterial agar well diffusion assay showed clear zone of inhibition of bacterial growth. In pharmacokinetic study, nanoparticle showed 4.6-fold and 7-fold increase in AUC_inf and half-life, respectively, as compared to free drug. RBx 11760 nanoparticle significantly reduced bacterial counts in lungs and improved the survival rate of immunocompromised mice as compared to free drugs. Thus, RBx 11760 loaded nanoparticles have strong potential to be used as nanomedicine against sensitive and drug resistant Staphylococcus aureus infections.

Synergistic Lysosomal Activatable Polymeric Nanoprobe Encapsulating pH Sensitive Imidazole Derivative for Tumor Diagnosis

Developing optical tumor imaging probes with minimal background noise is very important for its early detection of small lesions and accurate diagnosis of cancer. To overcome the bottleneck of low signal to noise ratio and sensitivity, it needs further improvement in fluorescent probe design and understanding of tumor development process. Recent reports reveal that lysosome's acidity in cancer cells can be below 4.5 with high Na⁺ /H⁺ exchange activity, which makes it an ideal target intracellular organelle for cancer diagnosis based on the variation of pH. Herein, a boron 2-(2'-pyridyl) imidazole complex derivative (BOPIM-N) is developed, with the ability to show a pH-activatable "OFF-ON" fluorescent switch by inhibiting twisted intramolecular charge transfer upon protonation at pH 3.8-4.5, which is studied for its selective viable cancer cell imaging ability in both in vitro and in vivo experiments. Interestingly, BOPIM-N can specifically emit green fluorescence in lysosomes of cancer cells, indicating its promising cancer cell specific imaging ability. More importantly, nanoformulated BOPIM-N probes can be specifically light-ON in tumor bearing site of nude mice with resolution up to cellular level, indicating its potential application in tumor diagnosis and precision medicine.

Intracellular delivery of peptide drugs using viral nanoparticles of bacteriophage P22: covalent loading and cleavable release

Viral nanoparticles of bacteriophage P22 are utilized for the intracellular delivery of peptides through covalent loading and cleavable release.

New Generation Nanomedicines Constructed from Self-Assembling Small-Molecule Prodrugs Alleviate Cancer Drug Toxicity

The therapeutic index for chemotherapeutic drugs is determined in part by systemic toxicity, so strategies for dose intensification to improve efficacy must also address tolerability. In addressing this issue, we have investigated a novel combinatorial strategy of reconstructing a drug molecule and using sequential drug-induced nanoassembly to fabricate supramolecular nanomedicines (SNM). Using cabazitaxel as a target agent, we established that individual synthetic prodrugs tethered with polyunsaturated fatty acids were capable of recapitulating self-assembly behavior independent of exogenous excipients. The resulting SNM could be further refined by PEGylation with amphiphilic copolymers suitable for preclinical studies. Among these cabazitaxel derivatives, docosahexaenoic acid-derived compound 1 retained high antiproliferative activity. SNM assembled with compound 1 displayed an unexpected enhancement of tolerability in animals along with effective therapeutic efficacy in a mouse xenograft model of human cancer, compared with free drug administered in its clinical formulation. Overall, our studies showed how attaching flexible lipid chains to a hydrophobic and highly toxic anticancer drug can convert it to a systemic self-deliverable nanotherapy, preserving its pharmacologic efficacy while improving its safety profile. Cancer Res; 77(24); 6963-74. ©2017 AACR.

Injectable Supramolecular Hydrogels as Delivery Agents of Bcl-2 Conversion Gene for the Effective Shrinkage of Therapeutic Resistance Tumors

Injectable hydrogels to deliver therapeutic genes in a minimally invasive manner and to achieve long term sustained release at tumor sites to minimize side effects are attractive for cancer therapy and precision medicine, but its rational design remains a challenge. In this report, an injectable supramolecular hydrogel system is designed based on the polypesudorotaxane formation between α-cyclodextrin (α-CD) and cationic methoxy-poly(ethylene glycol)-b-poly(ε-caprolactone)-b-poly(ethylene imine) (MPEG-PCL-PEI) copolymer, with the ability to form polyplexes with anionic plasmid DNA for effective sustained gene delivery. To be mentioned, the MPEG-PCL-PEI copolymers show similar pDNA binding ability, better gene transfection efficiency, lower cytotoxicity than nonviral gene transfection gold standard PEI (25 kDa), due to the formation of micelles and more stable polyplexes. More importantly, this MPEG-PCL-PEI/α-CD/pDNA supramolecular hydrogel shows a sustained release of pDNA in form of polyplex for up to 7 d. By taking these advantages, this supramolecular hydrogel system is applied as an injectable carrier for sustained Bcl-2 conversion gene release, in an in vivo rodent model of therapeutic resistant hepatocarcinoma with high expression of antiapoptotic Bcl-2 protein. This work represents the first time that injectable MPEG-PCL-PEI/α-CD supramolecular hydrogels possess good controllable release effect of Bcl-2 conversion genes in the form of polyplex to effectively inhibit in vivo tumor growth and this "enemy to friend" strategy will benefit various applications, including on-demand gene delivery and personalized medicine.

Systemic delivery of the tumor necrosis factor gene to tumors by a novel dual DNA-nanocomplex in a nanoparticle system

Many cancers fail to respond to immunotherapy as a result of immune suppression by the tumor microenvironment. The exogenous expression of immune cytokines to reprogram the tumor microenvironment represents an approach to circumvent this suppression. The present studies describe the development of a novel dual nanoparticle (DNP) system for driving DNA expression vectors encoding inflammatory cytokines in tumor cells. The DNP system consists of a DNA expression vector-cationic peptide nanocomplex (NC) surrounded by a diblock polymeric NP. Tumor necrosis factor alpha (TNF) was selected as the prototype cytokine for this system, based on its pleotropic inflammatory and anti-cancer activities. Our results demonstrate that the DNP system is highly effective in driving expression of TNF in tumor cells. We also demonstrate that the DNPs are effective in inducing apoptosis and anti-tumor activity. These findings support a novel immunotherapeutic approach for the intratumoral delivery of DNA vectors that express inflammatory cytokines.

Building the design, translation and development principles of polymeric nanomedicines using the case of clinically advanced poly(lactide(glycolide))-poly(ethylene glycol) nanotechnology as a model: An industrial viewpoint

The design of the first polymeric nanoparticles could be traced back to the 1970s, and has thereafter received considerable attention, as evidenced by the significant increase of the number of articles and patents in this area. This review article is an attempt to take advantage of the existing literature on the clinically tested and commercialized biodegradable PLA(G)A-PEG nanotechnology as a model to propose quality building and outline translation and development principles for polymeric nano-medicines. We built such an approach from various building blocks including material design, nano-assembly - i.e. physicochemistry of drug/nano-object association in the pharmaceutical process, and release in relevant biological environment - characterization and identification of the quality attributes related to the biopharmaceutical properties. More specifically, as envisaged in a translational approach, the reported data on PLA(G)A-PEG nanotechnology have been structured into packages to evidence the links between the structure, physicochemical properties, and the in vitro and in vivo performances of the nanoparticles. The integration of these bodies of knowledge to build the CMC (Chemistry Manufacturing and Controls) quality management strategy and finally support the translation to proof of concept in human, and anticipation of the industrialization takes into account the specific requirements and biopharmaceutical features attached to the administration route. From this approach, some gaps are identified for the industrial development of such nanotechnology-based products, and the expected improvements are discussed. The viewpoint provided in this article is expected to shed light on design, translation and pharmaceutical development to realize their full potential for future clinical applications.

Supramolecular cyclodextrin nanocarriers for chemo- and gene therapy towards the effective treatment of drug resistant cancers

A tumor active targeting β-cyclodextrin based nanocarrier β-NC-OEI-SS-FA was designed by the modification of star shaped cationic derivatives β-NC-OEI with folic acid through a disulfide bond, to co-deliver chemotherapeutic paclitaxel and the Nur77 gene for overcoming Bcl-2 mediated non-pump resistance by an "enemy to friend" strategy for potential drug resistant cancer therapy.

Functional Implications of the spectrum of BCL2 mutations in Lymphoma

Mutations in the translocated BCL2 gene are often detected in diffuse large B-cell lymphomas (DLBCLs), indicating both their significance and pervasiveness. Large series genome sequencing of more than 200 DLBCLs has identified frequent BCL2 mutations clustered in the exons coding for the BH4 domain and the folded loop domain (FLD) of the protein. However, BCL2 mutations are mostly contemplated to represent bystander events with negligible functional impact on the pathogenesis of DLBCL. BCL2 arbitrates apoptosis through a classic interaction between its hydrophobic groove forming BH1-3 domains and the BH3 domain of pro-apoptotic members of the BCL2 family. The effects of mutations are mainly determined by the ability of the mutated BCL2 to mediate apoptosis by this inter-member protein binding. Nevertheless, BCL2 regulates diverse non-canonical pathways that are unlikely to be explained by canonical interactions. In this review, first, we identify recurrent missense mutations in the BH4 domain and the FLD reported in independent lymphoma sequencing studies. Second, we discuss the probable consequences of mutations on the binding ability of BCL2 to non-BCL2 family member proteins crucial for 1) maintaining mitochondrial energetics and calcium hemostasis such as VDAC, IP3R, and RyR and 2) oncogenic pathways implicated in the acquisition of the 'hallmarks of cancer' such as SOD, Raf-1, NFAT, p53, HIF-1α, and gelsolin. The study also highlights the likely ramifications of mutations on binding of BCL2 antagonists and BH3 profiling. Based on our analysis, we believe that an in-depth focus on BCL2 interactions mediated by these domains is warranted to elucidate the functional significance of missense mutations in DLBCL. In summary, we provide an extensive overview of the pleiotropic functions of BCL2 mediated by its physical binding interaction with other proteins and the various ways BCL2 mutations would affect the normal function of the cell leading to the development of DLBCL.

Orphan Nuclear Receptor NR4A1 Binds a Novel Protein Interaction Site on Anti-apoptotic B Cell Lymphoma Gene 2 Family Proteins

B cell lymphoma gene 2 (Bcl-2) family proteins are key regulators of programmed cell death and important targets for drug discovery. Pro-apoptotic and anti-apoptotic Bcl-2 family proteins reciprocally modulate their activities in large part through protein interactions involving a motif known as BH3 (Bcl-2 homology 3). Nur77 is an orphan member of the nuclear receptor family that lacks a BH3 domain but nevertheless binds certain anti-apoptotic Bcl-2 family proteins (Bcl-2, Bfl-1, and Bcl-B), modulating their effects on apoptosis and autophagy. We used a combination of NMR spectroscopy-based methods, mutagenesis, and functional studies to define the interaction site of a Nur77 peptide on anti-apoptotic Bcl-2 family proteins and reveal a novel interaction surface. Nur77 binds adjacent to the BH3 peptide-binding crevice, suggesting the possibility of cross-talk between these discrete binding sites. Mutagenesis of residues lining the identified interaction site on Bcl-B negated the interaction with Nur77 protein in cells and prevented Nur77-mediated modulation of apoptosis and autophagy. The findings establish a new protein interaction site with the potential to modulate the apoptosis and autophagy mechanisms governed by Bcl-2 family proteins.

Liquid crystal nanoparticle formulation as an oral drug delivery system for liver-specific distribution

Liquid crystal nanoparticles have been utilized as an efficient tool for drug delivery with enhanced bioavailability, drug stability, and targeted drug delivery. However, the high energy requirements and the high cost of the liquid crystal preparation have been obstacles to their widespread use in the pharmaceutical industry. In this study, we prepared liquid crystal nanoparticles using a phase-inversion temperature method, which is a uniquely low energy process. Particles prepared with the above method were estimated to be ~100 nm in size and exhibited a lamellar liquid crystal structure with orthorhombic lateral packing. Pharmacokinetic and tissue distribution studies of a hydrophobic peptide-based drug candidate formulated with the liquid crystal nanoparticles showed a five-fold enhancement of bioavailability, sustained release, and liver-specific drug delivery compared to a host-guest complex formulation.

A nanoparticulate pre-chemosensitizer for efficacious chemotherapy of multidrug resistant breast cancer

Small-molecule chemosensitizers can reverse cancer multidrug resistance (MDR), thus significantly improving the in vitro effect of chemotherapy drugs for MDR cancer cells, however, their in vivo effects are not always very good, because they are difficult to effectively accumulate in tumor and enter the same cancer with chemotherapy drugs after systemic administration due to individual biopharmaceutical properties. To overcome these limitations, here we study a novel nanoparticular pre-chemosensitizer which can be also used as nanocarrier of chemotherapy drugs. We take an ‘all in one’ approach to develop a self-assembled nanoparticle formula of amphiphilic poly(curcumin-dithiodipropionic acid)-b-poly(ethylene glycol)-biotin. The nanoparticle is capable of tumor-targeted delivery, responsive degradation at the intracellular level of glutathione and subsequent intracellular co-release of the chemosensitizer curcumin and the encapsulated chemotherapeutic drug doxorubicin to maximize a synergistic effect of chemosensitization and chemotherapy. We demonstrate that the antitumor efficacy of nanoparticle is much superior to that of doxorubicin in the multidrug resistant MCF-7/ADR xenografted nude mice.

Polymer-based nanoparticles for protein delivery: design, strategies and applications

Therapeutic proteins have attracted significant attention as they perform vital roles in various biological processes. Polymeric nanoparticles can offer not only physical protection from environmental stimuli but also targeted delivery of such proteins to specific sites, enhancing their therapeutic efficacy.

Intracellular Targeting of the Oncogenic MUC1-C Protein with a Novel GO-203 Nanoparticle Formulation

PURPOSE

The MUC1-C oncoprotein is an intracellular target that is druggable with cell-penetrating peptide inhibitors. However, development of peptidyl drugs for treating cancer has been a challenge because of unfavorable pharmacokinetic parameters and limited cell-penetrating capabilities.

EXPERIMENTAL DESIGN

Encapsulation of the MUC1-C inhibitor GO-203 in novel polymeric nanoparticles was studied for effects on intracellular targeting of MUC1-C signaling and function.

RESULTS

Our results show that loading GO-203 into tetrablock polylactic acid (PLA)-polyethylene glycol (PEG)-polypropylene glycol (PPG)-PEG copolymers is achievable and, notably, is enhanced by increasing PEG chain length. In addition, we found that release of GO-203 from these nanoparticles is controllable over at least 7 days. GO-203/nanoparticle treatment of MUC1-C-positive breast and lung cancer cells in vitro was more active with less frequent dosing than that achieved with nonencapsulated GO-203. Moreover, treatment with GO-203/nanoparticles blocked MUC1-C homodimerization, consistent with on-target effects. GO-203/nanoparticle treatment was also effective in downregulating TIGAR, disrupting redox balance, and inhibiting the self-renewal capacity of cancer cells. Significantly, weekly administration of GO-203/nanoparticles to mice bearing syngeneic or xenograft tumors was associated with regressions that were comparable with those found when dosing on a daily basis with GO-203.

CONCLUSIONS

These findings thus define an effective approach for (i) sustained administration of GO-203 in polymeric PLA-(PEG-PPG-PEG) nanoparticles to target MUC1-C in cancer cells and (ii) the potential delivery of other anticancer peptide drugs.

Intelligent Nanoparticles for Advanced Drug Delivery in Cancer Treatment

Treatment of cancer using nanoparticle-based approaches relies on the rational design of carriers with respect to size, charge, and surface properties. Polymer-based nanomaterials, inorganic materials such as gold, iron oxide, and silica as well as carbon based materials such as carbon nanotubes and graphene are being explored extensively for cancer therapy. The challenges associated with the delivery of these nanoparticles depend greatly on the type of cancer and stage of development. This review highlights design considerations to develop nanoparticle-based approaches for overcoming physiological hurdles in cancer treatment, as well as emerging research in engineering advanced delivery systems for the treatment of primary, metastatic, and multidrug resistant cancers. A growing understanding of cancer biology will continue to foster development of intelligent nanoparticle-based therapeutics that take into account diverse physiological contexts of changing disease states to improve treatment outcomes.

Intracellular delivery of peptide cargos using iron oxide based nanoparticles: studies on antitumor efficacy of a BCL-2 converting peptide, NuBCP-9

Delivering peptides into cells targeting the undruggable oncoproteins is an emerging area in cancer therapeutics. Here we report a novel nanoparticle-based delivery system that can transport therapeutic cargos to the intracellular sites without the need for a cell transduction or penetration domain (CPP). In the present study, we have used iron oxide nanoparticles to deliver an oncopeptide, NuBCP-9, targeting the BCL-2 BH3 domain. Citric acid/2-bromo 2-methylpropanoic acid (CA/BMPA)-capped SPIONs were used to immobilize and deliver the NuBCP-9 peptide to the cancer cells without any noticeable off-target effects. Our results have demonstrated that NuBCP-9-SPIONs efficiently penetrate into cancer cells and bind to its intracellular target protein BCL-2. Moreover, significant inhibition of proliferation and substantial induction of cell death were observed when cancer cells were treated with NuBCP-9-SPIONs at different time intervals. Importantly, the IC50 values for killing of breast cancer cells with NuBCP-9-SPIONs were much lower compared to cells treated with the NuBCP-9 peptide linked with a CPP (Arg-8; NuBCP-9-R8). Molecular and biochemical analyses further supported that NuBCP-9-SPIONs killed breast cancer cells by apoptosis-mediated mechanisms. Furthermore, our data demonstrated that administration of NuBCP-9-SPIONs to mice bearing Ehrlich ascites tumors (EAT) was associated with loss of tumorigenicity and extensive apoptosis in tumor tissues. Taken together, these findings show that a non-CPP-tagged peptide can be successfully delivered to undruggable intracellular oncotargets using SPIONs.