Effective Anticancer Drug Delivery Research Articles

Abstract 279: Transient opening of the blood brain barrier by Tumor Treating Fields (TTFields)

Abstract Introduction Alternating electric fields of intermediate frequency and low intensity, known as Tumor Treating Fields (TTFields), are an effective and clinically approved approach for treatment of glioblastoma (GBM). The optimal frequency for treatment of glioma cells based on the cytotoxic response is at 200 kHz. Combination of TTFields with chemotherapy appears to be synergistic with further increase in overall survival of patients with GBM, beyond that with chemotherapy alone. The blood brain barrier (BBB) limits delivery of a majority of drugs to the brain thus limiting treatment options for GBM patients. Recent in vitro studies suggest that TTFields applied at 100 kHz can disturb the BBB. In this study, we investigated the potential use of TTFields to transiently disturb the BBB in animal models. Methods BBB permeation was tested in healthy rats subsequently to 100 kHz TTFields or sham (heat) application to the rat head. BBB permeability was analyzed by several staining agents: (1) Evans Blue (EB) that was quantified at 610 nm in brain homogenates; (2) 4 kDa TRITC-dextran (TD) that was quantified based on fluorescence intensity in brain cryosections; and (3) the MRI contrast agent Gd-DTPA. Accumulation and clearance of Gd-DTPA were tracked by serial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). In addition, brain sections were stained for claudin-5, occludin, PECAM-1 and immunoglobulin G (IgG). BBB permeation induced by TTFields was further evaluated in rats orthotopically bearing F98 glioma cells and treated with TTFields at 100 kHz in combination with the chemotherapeutic drug paclitaxel (PTX) for a duration of 72 h. Tumor cell proliferation was assessed by Ki67 staining and the tumor volume was measured by T2 weighted MRI. Results BBB permeation of EB and TD staining agents was observed in the brains of healthy rats after TTFields application. Moreover, brain cryosections displayed delocalization of claudin-5 and occludin, but not of PECAM-1. Accumulation of IgG in the brain parenchyma was also noted. Confirming these observations, DCE-MRI post-TTFields treatment showed accumulation of Gd in the brain. Return to normal BBB integrity was detected 96 h after TTFields treatment cessation, indicating the effect was transient and reversible. In GBM-induced rats, the combination of PTX (a drug which normally does not cross the BBB) with TTFields significantly decreased tumor cell proliferation and tumor volume compared to animals treated with TTFields alone, sham alone, or sham combined with PTX. Conclusions Administration of 100 kHz TTFields to the brain of rats led to transient alterations in BBB integrity and permeability, allowing increased uptake of combination chemotherapy. These data indicate that TTFields treatment may be a feasible, novel clinical strategy for transient opening of the BBB to allow for enhanced and more effective delivery of permeable and non-permeable anticancer drugs to the brain. Citation Format: Catherine Tempel Brami, Ellaine Salvador, Almuth F. Kessler, Malgorzata Burek, Tali Voloshin, Moshe Giladi, Ralf-Ingo Ernestus, Mario Löhr, Carola Förster, Carsten Hagemann. Transient opening of the blood brain barrier by Tumor Treating Fields (TTFields) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 279.

Anticancer and Antimicrobial Activity Evaluation of Cowpea-Porous-Starch-Formulated Silver Nanoparticles

Health issues involving inadequate treatment of diseases such as cancer and microbial infections continue to be the subject of much ongoing recent research. Biosynthesized silver nanoparticles (AgNPs) were characterized using Transmission Electron Microscopy (TEM), Zeta Sizer, Ultraviolet (UV), and Fourier Transform Infrared (FTIR) spectroscopy. Their antimicrobial activity was evaluated on selected Gram-positive and Gram-negative bacterial strains, using the disc diffusion and broth dilution assays. Cell viability profiles were evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis studies on selected human noncancer and cancer cells. The biosynthesized AgNPs were evaluated to be spherical clusters, with sizes between 40 and 70 nm. The absorption peak at 423 nm and the presence of polyphenols confirmed the synthesis and stabilization of these tested AgNPs. The AgNPs showed a good stability of −23.9 ± 1.02 mV. Good antimicrobial activity (6.0–18.0 mm) was seen on all tested bacteria at a minimum inhibitory concentration (MIC) ranging from 5 to 16 μg/ml, with the highest activity seen against Gram-negative Escherichia coli (18 ± 0.5 mm), and the lowest activity was seen against Gram-positive Listeria monocytogenes (6.0 ± 0.4 mm) after treatment with the AgNPs. These NPs showed a concentration-dependent and cell-specific cytotoxicity with low IC50 values (41.7, 56.3, and 63.8 μg/ml). The NPs were well tolerated by tested cells as indicated by a more than 50% cell viability at the high dose tested and low apoptotic indices (<0.2). These findings indicated that these biosynthesized AgNPs showed great potential as effective antibacterial agents and anticancer drug delivery modalities.

Angiogenesis as a hallmark of solid tumors - clinical perspectives.

Angiogenesis is a key and early step in tumorigenesis, and is known as a hallmark of solidtumors and a key promoter of tumor recurrence. Unlike normal tissue vessels, the architecture of the tumor vasculature is abnormal, being leaky, tortuous, fragile and blind-ended. Perivascular cells are either detached or absent, causing reduction of vascular integrity, an increase in vessel immaturity, incoherent perfusion, defective functionality and enhanced tumor dissemination and metastasis. The abnormal tumor vasculature along with the defective tumor vessel functionality finally causes bouts of hypoxia and acidity in the tumor microenvironment (TME), further reinvigorating tumor aggression. Interstitial hypertension or high interstitial fluid pressure (IFP) is an outcome of tumor hyper-permeability. High IFP can be a barrier for either effective delivery of anti-cancer drugs toward the TME or accumulation of drugs within the tumor area, thus promoting tumor resistance to therapy. Some tumors do, however, not undergo angiogenesis but instead undergo vessel co-option or vascular mimicry, thereby adding another layer of complexity to cancerdevelopment and therapy. Combination of anti-angiogenesis therapy with chemotherapy and particularly with immune checkpoint inhibitors (ICIs) is a promising strategy for a number of advanced cancers. Among the various approaches for targeting tumor angiogenesis, vascular normalization is considered as the most desired method, which allows effective penetration of chemotherapeutics into the tumor area, thus being an appropriate adjuvantto other cancer modalities.

Development and characterization of gel-in-water nanoemulsion as a novel drug delivery system

The effective delivery of anti-cancer drugs with minimal side effects and better therapeutic efficacy has remained an active area of research for many decades. Organogels have gained attention in recent years as potential drug delivery systems due to their high bioavailability, no first-pass metabolism and rapid action. Considering this, in the current study an organogel based nanoemulsion was developed aiming to effectively deliver hydrophobic drugs via encapsulation within in situ gellable organogel droplets, termed as gel-in-water (G/W) nanoemulsion. G/W nanoemulsion was prepared using a combination of lipiodol and organogelator 12-hydroxystearic acid (12-HSA) as inner gel phase; dispersed in water by ultrasonication and stabilized with polyoxyethylene hydrogenated castor oil (HCO-60) as a surfactant. The prepared nanoemulsion showed high drug loading efficiency (≈97%) with a mean diameter of 206 nm. Lower polydispersity index (PdI) value (≈0.1) suggests monodispersed nature of G/W nanoemulsion in the continuous phase. G/W nanoemulsion was found stable over six months in terms of particle size, zeta potential and pH at different storage temperatures. There was no cytotoxic effect of prepared G/W nanoemulsion on primary hepatocytes in vitro. In contrast, paclitaxel-loaded G/W showed a significant decrease in melanoma cell growth (*p < 0.05) both in vitro and in vivo. Our results support the hypothesis that organogel based nanoemulsions can be a promising drug delivery system.

PH and redox dual-sensitive drug delivery system constructed based on fluorescent carbon dots.

Herein, a pH and redox dual-responsive drug delivery system (CDs–Pt(iv)–PEG) was developed based on fluorescence carbon dots (CDs). In this system, cisplatin(iv) prodrug (Pt(iv)) was selected as a model drug to reduce toxic side effects. The aldehyde-functionalized monomethoxy polyethylene glycol (mPEG-CHO) was conjugated to CDs–Pt(iv) to form pH sensitive benzoic imine bond. Owing to the slightly acidic tumor extracellular microenvironment (pH 6.8), the benzoic imine bond was then hydrolyzed, leading to charge reversal and decrease in the hydration radius of the drug-carrying, which facilitated in vivo circulation and tumor targeting. Notably, the cytotoxicity of the drug delivery system on cancer cells was comparable to that of cisplatin, while the side effects on normal cells were significantly reduced. In addition, the system realized recognition of cancer cells by the high-contrast fluorescent imaging. In conclusion, the CDs–Pt(iv)–PEG system provided a promising potential for effective delivery of anticancer drugs and cancer cells screening.

Biodegradable diblock copolymeric PEG-PCL nanoparticles: Synthesis, characterization and applications as anticancer drug delivery agents

Poly (ethylene glycol) methyl ether-block-poly (Ɛ-caprolactone) copolymers are useful biomedical materials owing to their amphiphilic nature, biodegradability, biocompatibility and also due to their semi-crystalline form having a low glass transition temperature. Due to their slow drug release profile, PEG-PCL copolymers are excellent candidates for sustained delivery applications over a period of time of more than a year. This unique property has provoked their relevance specially in the area of anticancer drug delivery applications in the form of various nanoaggregates like microspheres, nanogels, nanospheres, polymersomes, micelles, etc. A large variety of anticancer drugs/bioactives have been encapsulated in PEG-PCL copolymers for developing effective anticancer drug delivery systems and also for producing controlled drug release profiles. In recent times, PEG-PCL copolymers based nanoparticles have shown tremendous advancements as anticancer drug delivery vehicles owing to their higher drug loading capacities of the hydrophobic drugs, enhanced bioavailability, keeping away from being overpowered by way of phagocytes, decreased blasted discharge, and also in increasing the scattering time of drug within the blood stream during their systemic inoculation. These nano-formulated drug delivery systems can be used for the delivery of anticancer drugs at a specific site in a targeted approach. The developed nano-formulations possess promising potential in the treatment of cancer with improved anticancer efficacy and reduced toxicity invivo. In the current review, our main focus is to highlight the development and synthesis of different types of PEG-PCL copolymers (both conventional and greener approaches) along with the physico-chemical characterization techniques used primarily for the PEG-PCL co-polymeric systems. We have also summarized the uses of PEG-PCL co-polymeric nano formulations with various anticancer drugs as drug delivery platforms in the area of anticancer chemotherapy.

Multifunctional nanoparticles of paclitaxel and cyclodextrin–polypeptide conjugates with in vitro anticancer activity

In this study, the cyclodextrin polypeptide (R8-CMβCD) was successfully synthesized by the conjugation of a cell-penetrating peptide (R8) with carboxymethyl-β-cyclodextrin (CMβCD) via the carbon diamine reaction. Then, paclitaxel-loaded nanoparticles (PTX@R8-CMβCD NPs) was prepared. Results of transmission electron microscopy (TEM) showed that PTX@R8-CMβCD NPs were spherical with smooth surfaces and an average diameter about 144 nm. The amount of PTX released from NPs was less than 20% at pH7.4, but it increased significantly to 80% in the weakly acidic cytoplasm of tumors (pH5.0). Furthermore, PTX@R8-CMβCD NPs promoted the cellular uptake of PTX. Further studies on the mechanism showed that cellular uptake of PTX@R8-CMβCD NPs could rely on multiple pathways. In addition, the NPs had the ability to inhibit P-gp efflux pumps. Cytotoxicity tests showed that the NPs had no side effects. Taken together, PTX@R8-CMβCD NPs is an effective anticancer drug delivery system, and the material (R8-CMβCD) may be a promising anti-cancer drug carrier.

A Leucine Aminopeptidase-Activated Theranostic Prodrug for Cancer Diagnosis and Chemotherapy

Currently, chemotherapy is a widely used and important treatment for cancer. However, almost all of the treatments have shortcomings associated with poor specificity and high toxicity, which results in severe side effects to normal cells and tissue. This is a very important problem, and yet, it currently remains unanswered. Therefore, the development of the method for the more effective delivery of anticancer drugs to their targets and real-time monitoring of the localization of the drugs are very important. Herein, we designed a theranostic prodrug: CPT-p-Leu, which was constructed using fluorescent camptothecin (CPT), a self-immolative linker and leucine (Leu) residue. Upon exposure to LAP (leucine aminopeptidase: LAP), the amide bond in CPT-p-Leu will be cleaved, followed by an intramolecular 1,6-elimination, which triggers the active anticancer drug (CPT) release and recovers the fluorescence of CPT. With our design, the anticancer drug, CPT, can be used as both a drug and a fluorescence reporter, making our system suitable to accurately and effectively track the released CPT distribution. Based on this strategy, CPT-p-Leu could achieve the chemoselective detection of LAP and monitoring of the anticancer drug release. Furthermore, it also provides a very convenient way to accurately determine the location of the released drug in living samples. In addition, CPT-p-Leu shows a good cell membrane permeability and enhanced cytotoxicity toward LAP overexpressing cancer cells. We anticipate that our research will facilitate the development of improved theranostic systems for cancer therapy.

Synthesis and characterization of dual pH-and thermo-responsive graphene-based nanocarrier for effective anticancer drug delivery

In the present work, the surface of graphene oxides (GO) have been modified with biodegradable and hydrophilic polymeric compounds, poly(N-vinylcaprolactam) (PNVCL) and poly(glycolic acid) over covalent functionalization for effectual loading and release of oxaliplatin anticancer drug. The oxaliplatin was loaded onto the graphene oxide surface of GO-PNVCL-PGA composite by the π-π interactions. The release profile of oxaliplatin from GO-PNVCL-PGA was carried out at two different pHs (5.4 and 7.4) and temperatures (27 and 45 °C). The DSC analyze confirmed that the modification of PNVCL with polyglycolide caused to change transition temperatures range from 32 to 34 °C to the normal body temperature range (36–37 °C). Also, the cytotoxicity effects of oxaliplatin, GO-PNVCL-PGA, and oxaliplatin loaded GO-PNVCL-PGA on human breast cancer cells (MCF-7) was estimated via MTT assay. The outcomes indicated that the cytotoxicity of oxaliplatin loaded GO-PNVCL-PGA was higher than free oxaliplatin. Mainly, oxaliplatin loaded GO-PNVCL-PGA has a more cytotoxic effect than GO-PNVCL-PGA against cancer cells, which was representing that oxaliplatin loaded GO-PNVCL-PGA can be applied as encouraging compound for biological utilization and drug delivery carriers.

Enzyme-activatable polymer-drug conjugate augments tumour penetration and treatment efficacy.

A tumour microenvironment imposes barriers to the passive diffusion of molecules, which renders tumour penetration an unresolved obstacle to an effective anticancer drug delivery. Here, we present a γ-glutamyl transpeptidase-responsive camptothecin-polymer conjugate that actively infiltrates throughout the tumour tissue through transcytosis. When the conjugate passes on the luminal endothelial cells of the tumour blood vessels or extravasates into the tumour interstitium, the overexpressed γ-glutamyl transpeptidase on the cell membrane cleaves the γ-glutamyl moieties of the conjugate to generate positively charged primary amines. The resulting cationic conjugate undergoes caveolae-mediated endocytosis and transcytosis, which enables transendothelial and transcellular transport and a relatively uniform distribution throughout the tumour. The conjugate showed a potent antitumour activity in mouse models that led to the eradication of small solid tumours (~100 mm3) and regression of large established tumours with clinically relevant sizes (~500 mm3), and significantly extended the survival of orthotopic pancreatic tumour-bearing mice compared to that with the first-line chemotherapeutic drug gemcitabine.

Barbiturate derived amphiphilic homopolymers: synthesis, characterization, self-assembly and anticancer drug delivery.

Aim: Our aim was to synthesis and characterization of amphiphilic norbornene-derived thiobarbiturate homopolymers (NDTH 1-4) for drug delivery. Methods: Ring-opening metathesis polymerization technique was used to prepare a series of homopolymers. The hydrophobicity is introduced by increasing the number of carbon chains ([-CH2-]n; n=1, 2, 3 & 4) in between norbornene backbone and thiobarbiturate species. Results: These vesicular aggregates have been used as anticancer Doxorubicin drug delivery vehicles at the acidic (5.5) and physiological (7.4) pHs. Confocal laser-scanning microscopy has demonstrated that the drug-loaded vesicles are easily internalized into living cells. Conclusion: Amphiphilic norbornene-derived thiobarbiturate homopolymer assemblies showed efficient nanocarrier for effective anticancer drug delivery.

Albumin-Modified Cationic Nanocarriers To Potentially Create a New Platform for Drug Delivery Systems.

Cationic nanocarriers have emerged as promising nanoparticle systems for the effective delivery of nucleic acid and anticancer drugs to cancer cells. A positive charge is desirable for promoting cell internalization, whereas it also causes some adverse effects, such as toxicity and rapid clearance by mononuclear phagocytic systems. Herein, a new strategy of modifying cationic polymer micelles with albumin forming a protein corona to improve the surface physiochemical properties is reported. The corona with a monolayer or a multilayer was constructed depending on the albumin concentration, and the proteins would denature in different degrees due to the interaction with the surface of cationic micelles. It is demonstrated that multilayer albumin corona is beneficial to prevent macrophage uptake, increase accumulation in tumor tissues, and reduce toxic side effects to normal tissues. Our work provides a promising method to modify the cationic nanoplatform by optimizing the biosecurity and bioavailability for potential application in drug delivery.

Inhalable Nanostructures for Lung Cancer Treatment: Progress and Challenges

Background: Worldwide, lung cancer is the major cause of deaths due to cancer. Most of the lung cancer cases are categorized as 85% cases of non-small cell lung cancer, while remainder 15% cases are known as small cell lung cancer. The long survival time as well as the improved quality of life for patients undergoing lung cancer using conventional chemotherapy is still not satisfactory. Therefore, robust research undergoes development of drug delivery system which increased drug at target side with reduced systemic side effect. Method: Bibliography database reviewed various inhalable nanostructured drug delivery strategies for effective delivery of anticancer drugs to lung cancer which are designed to improve the therapeutic index of anticancer drugs throughout improvement of their stability as well as bioavailability. Results: It has been reported that nanostructure based inhalation chemotherapy is more successful targeting system and also offers reduced side effects than conventional chemotherapy. Conclusion: Thus, the review highlights the critical issues, strategies for delivery and provides detail on various inhalable nanostructures for anticancer drug delivery along with toxicity concerns as well as rationale behind development of inhalable nanostructures.

Pluronic F127 self-assembled MoS2 nanocomposites as an effective glutathione responsive anticancer drug delivery system.

In this study, bio-responsive polymeric MoS2 nanocomposites were prepared for use as a drug carrier for cancer therapy. Herein, we report the synthesis and demonstrate the self-assembly of pluronic F127 (PF127) on a cystamine–glutathione–MoS2 (CYS–GSH–MoS2) system, which can be used for GSH-triggered drug release under biological reducing conditions. The reduction-sensitive disulfide bond containing CYS was incorporated between the amphiphilic copolymer PF127 and GSH–MoS2 to achieve feasible drug release. Percent drug loading capacity and encapsulation efficiency were 51.3% and 56%, respectively. In addition, when the MoS2–GSH–CYS–PF127 nanocomposite was incubated in a GSH environment, the morphology of the nanocomposite tended to change, ultimately leading to drug release. The drug-loaded PF127–CYS–GSH–MoS2 polymeric nanocomposites efficiently released 52% of their drug content after 72 h of incubation in a GSH reduction environment. The HeLa cells treated with DOX loaded MoS2–GSH–CYS–PF127 showed 38% toxicity at drug concentration of 40 μg, which indicated that the successfully released of drug from carrier and caused the cell death. Further, fluorescence microscopy images of HeLa cells revealed the potential behavior of the MoS2–GSH–CYS–PF12 nanocomposite during the 2- and 4 h incubation periods; the nanocomposite was only found in the cytoplasm of HeLa cells. Interestingly, after 6 h of incubation, the drug was slowly released from the nanocomposite and could enter the nucleus as confirmed by fluorescence imaging of HeLa cells. Altogether, our synthesized PF127-coated MoS2 nanocomposite could be effectively adopted in the near future as a GSH-sensitive drug carrier.

Revival of a potent therapeutic maytansinoid agent using a strategy that combines covalent drug conjugation with sequential nanoparticle assembly

Maytansine and its related analogues are a class of highly potent anti-proliferation agents that have failed to be exploited as clinical drugs for human therapy due to unacceptable systemic toxicity. Here, we delineate a novel strategy that combines rational drug conjugation with subsequent nanoparticle assembly to systemically deliver this highly potent and toxic drug. To demonstrate this concept, we covalently coupled the thiolated maytansine derivative, the DM1 agent, to amphiphilic block co-polymers, polyethylene glycol (PEG)-block-polylactide (PLA), in varying molecular weights to generate two prodrug constructs (i.e., PEG2K-PLA2K-DM1 and PEG2K-PLA4K-DM1) via the maleimide-thiol reaction. The resulting two constructs are amenable to self-assembly in aqueous solutions and are systemically injectable for preclinical studies. In vivo evaluations indicate that PEG-PLA-DM1 conjugate-assembled nanoparticles (NPs) display substantially reduced drug toxicity compared to the free drug forms and NPs that physically encapsulate DM1. Furthermore, following systemic administration, these nanodrugs produced superior therapeutic efficacy over free DM1 in a colon tumor xenograft-bearing mouse model. Therefore, this study provides evidence that the conjugation of toxic drugs to assembling copolymers enables the alleviation of cancer drug toxicity and effective delivery of anticancer drugs. Thus, this DM1-formulated platform represents a new generation of nanotherapeutics that are available for further clinical evaluation.

Highly stable photosensitive supramolecular micelles for tunable, efficient controlled drug release

Simple fabrication and manipulation of multi-stimuli responsive supramolecular polymers based on multiple, self-complementary, hydrogen bond interactions with the desired self-assembly behavior and desirable micellar properties for effective drug delivery under physiological conditions remains a grand challenge. Herein, we successfully developed a dual light- and temperature-responsive uracil-based polymer, BU-PPG, that spontaneously self‐assembles to form micelle-shaped nanoparticles in phosphate-buffered saline (PBS) via supramolecular interactions between uracil moieties. The resulting micelles exhibited controlled light-sensitive photodimerization, a low critical micellization concentration, low cytotoxicity towards MCF-7 cells and tunable drug-loading capacity, as well as extremely high drug-entrapment stability in media containing serum. These features make BU-PPG micelles highly attractive as a potential candidate for safe, effective delivery of anticancer drugs. Importantly, when irradiated with UV light at 254 nm, the drug-loaded irradiated BU-PPG micelles could be easily tuned to obtain the desired phase transition temperature, remained highly stable under normal physiological conditions for prolonged periods of time, and rapidly released the encapsulated drug when the temperature was increased to 40 °C due to an efficient temperature-induced hydrophilic-hydrophobic phase transition. Collectively, these advantages suggest the newly developed BU-PPG supramolecular system may represent a promising new strategy towards the development of controlled release drug delivery systems.

Facile Fabrication of Oxidation-Responsive Polymeric Nanoparticles for Effective Anticancer Drug Delivery.

Reactive oxygen species (ROS) are highly overproduced in cancerous tissues, and thus oxidation-responsive nanoparticles (NPs) have emerged as a promising drug carrier for cancer-targeted drug delivery. In this study, we successfully synthesized poly(vanillyl alcohol- co-oxalate) (PVAX) polymer with an excellent ROS-responsive capacity. A well-established emulsion-solvent evaporation method was used to fabricate PVAX-based curcumin (CUR)-loaded NPs (PVAX-NPs) and their counterparts (poly(lactic- co-glycolic acid)-based CUR-loaded NPs, PLGA-NPs). It was found that these NPs had a hydrodynamic particle size of approximately 245 nm, narrow size distribution (polydispersity index less than 0.1), negative zeta potential (around -18 mV), smooth surface appearance, and high drug encapsulation efficiency. Moreover, we found that the CUR release rate of PVAX-NPs was greatly increased in the presence of a hydrogen peroxide-rich environment due to the cleavage of polyoxalate ester bonds in PVAX polymer, resulting in the evenly distribution of CUR within the whole cancer cells. More importantly, PVAX-NPs exhibited much stronger anticancer activities and pro-apoptotic capacities than PLGA-NPs both in vitro and in vivo. These results clearly demonstrate that these ROS-responsive PVAX-NPs can be exploited as a robust anticancer drug delivery platform in chemotherapy.

Hydrophobicity-Adaptive Nanogels for Programmed Anticancer Drug Delivery.

Reconciling the conflicting needs for a prolonged circulation time, enhanced cellular uptake by bulk tumor cells and cancer stem cells (CSCs), and extensive tumor tissue penetration remains a major challenge for current nano drug delivery systems. Here we describe smart poly( N-isopropylacrylamide)-based nanogels with a fast adaptive hydrophobicity to solve these contradictory requirements for enhanced cancer chemotherapy. The nanogels are hydrophilic in the blood to prolong their circulation time. Once they accumulate at tumor sites, they rapidly become hydrophobic in response to tumor extracellular acidity. The adaptive hydrophobicity of the nanogels facilitates tumor accumulation, deep tumor penetration, and efficient uptake by bulk tumor cells and CSCs, resulting in a greater in vivo enrichment in tumor cells and side population cells. Together with lysosomal pH-regulated charge reversal and redox-responsive intracellular drug release, the nanogels escape from lysosomes and release their cargo doxorubicin. Thus, the nanogels significantly improve the in vivo anticancer efficacy and decrease side effects of doxorubicin. Strikingly, the ratio of CSCs is greatly decreased after treatment with the nanogels loaded with doxorubicin. Our current study provides new insights into designing effective anticancer drug delivery systems.

Synthesis of New Antibacterial Cubane-based Nanocomposite and its Application in Combination Cancer Therapy.

The need for therapeutically effective anticancer drug delivery systems constantly persuades researchers to explore novel strategies. In this study a novel cubane based antibacterial nanocomposite was tailored as dual chemotherapy drug delivery vesicle in order to increase the therapeutic outcome in cancer therapy. The physico-chemical characterization of engineered nanocarrier was assessed by Fourier transforms infrared spectroscopy (FTIR), Hydrogen nuclear magnetic resonance spectroscopy (1H NMR), Thermogravimetric analysis (TGA), and Field emission scanning electron microscopy-energy dispersive using X-ray (FESEMEDX). The antibacterial activity of novel developed nanocomposite was tested by determining minimum inhibitory concentration (MIC) values against Pseudomonas aeruginosa, Escherichia Coli and Candida albicans. In order to investigate the efficacy of novel engineered nanocomposite (with average particle size of 50 nm) as dual anticancer drug delivery, DOX and MTX were bind to nanocarrier with encapsulation efficiency and loading content of around 97.3 ± 2.7% and 20.8 ± 1.6 %, respectively. Dual drugs released simultaneously with distinct tumor targeted, pH responsive sustained release manner. Moreover, the probable antitumoral activity of this engineered nanocomposite system against MCF7 cell lines was evaluated by MTT assay and cell cycle studies. The outcomes showed that novel engineered nanocomposite had no cytotoxic effects, while DOX@MTX-loaded nanocomposite possessed higher growth inhibition property and higher S-phase arrest as compared to cells treated with DOX@MTX alone. It was concluded that this novel cubane based drug delivery vehicle could process antibacterial and anticancer therapeutics spontaneously, representing promising tumor targeted system in nanomedicine.

Chitosan (CMD)-mediated co-delivery of SN38 and Snail-specific siRNA as a useful anticancer approach against prostate cancer.

Prostate cancer is known as the most common malignancy in men. Chitosan has generated great interest as a useful biopolymer for the encapsulation of small interfering RNA (siRNA). Due to cationic nature, chitosan is able to efficiently encapsulate siRNA molecules and form nanoparticles. Furthermore, the biocompatible and biodegradable attributes of chitosan have paved the way for its potential application in the in vivo delivery of therapeutic siRNAs. In this study, we aimed to design chitosan/CMD nanoparticles for the efficient encapsulation of the anti-cancer drugs SN38 and Snail-specific siRNA. Physicochemical characteristics, growth inhibitory properties, and anti-migratory capacities of the dual delivery of SN38-Snail siRNA CMD-chitosan nanoparticles were investigated in prostate cancer cells. Our findings provided evidence for the suggestion that, ChNP-CMD-SN38-siRNA treated cells, the mRNA level of snail decreased from 1.00 to 0.30 (±0.14) and 0.09 (±0.04) after 24h and 48h, respectively. Additionally, the fold induction of E-cadherin and Claudin-1 increased from 1.00 to now 3.12 (±0.62), 3.02 (±0.28) after 24h and 5.6 (±0.91), 4.42 (±0.51) after 48h, respectively. Also, co-delivery of SN38 and Snail-specific siRNA by an appropriate nanocerrier (chitosan nanoparticles) could reduce the viability, proliferation, and migration of PC-3 cells. In conclusion, ChNPs encapsulating SN38 and Snail-specific siRNA may represent huge potential as an effective anti-cancer drug delivery system for the treatment of prostate cancer.