Use of novel taurine-chitosan mediated liposomes for enhancing the oral absorption of doxorubicin via the TAUT transporter

Our research aimed to enhance the oral bioavailability of doxorubicin hydrochloride (DOX·HCl) while minimizing the potential for myocardial toxicity. To achieve this goal, we developed a new method that utilizes a coating material to encapsulate the drug in liposomes, which can specifically target intestinal taurine transporter proteins. This coating material, TAU-CS, was created by combining taurine with chitosan. We characterized TAU-CS using various methods, including 1H NMR, FT-IR, and scanning electron microscopy (SEM). The resulting liposomes exhibited a regular spherical morphology, with a particle size of 195.7 nm, an encapsulation efficiency of 91.23 %, and a zeta potential of +11.65 mV. Under simulated gastrointestinal conditions, TAU-CS/LIP@DOX·HCl exhibited good stability and slow release. Pharmacokinetic studies revealed that, compared with DOX·HCl, TAU-CS/LIP@DOX·HCl had a relative bioavailability of 342 %. Intracellular uptake, immunofluorescence imaging, and permeation assays confirmed that the taurine transporter protein mediates the intestinal uptake of these liposomes. Our study suggested that liposomes coated with TAU-CS could serve as an effective oral delivery system and that targeting the taurine transporter protein shows promise in enhancing drug absorption.

Nanodrug regulates ROS homeostasis via enhancing fatty acid oxidation and inhibiting autophagy to overcome tumor drug resistance

The treatment of drug-resistant tumors poses a significant challenge in the field of tumor therapy. Disrupting the homeostasis of reactive oxygen species (ROS) within tumor cells may represent a pivotal strategy for overcoming the prevalent issue of drug resistance. However, the restricted sustainability of ROS generation and the increased autophagy capacity exhibited by tumor cells hinder the application of ROS-based therapies. In this study, we developed liposome nanoparticles (Ato/CQ@L) for co-encapsulation of atorvastatin (Ato), an activator of AMP-activated protein kinase (AMPK), and chloroquine (CQ), an autophagy inhibitor. Upon internalization by tumor cells, Ato upregulated carnitine palmitoyltransferase 1(CPT1) concentration and promoted fatty acid oxidation (FAO) within the tumor cells. The process of FAO coupled with an abundance of fatty acid substrates, facilitates a sustained generation of ROS production. Concurrently, a positive feedback loop is established between escalated concentration of ROS and AMPK protein levels, resulting in a persistent elevation in ROS levels. In addition, CQ disrupted lysosomes, leading to an increased lysosomal pH and reducing autophagy in tumor cells. In both in vivo and in vitro experiments, the Ato/CQ@L treatment group exhibited a considerable enhancement in tumor cell apoptosis, validating the efficacy of this combined therapy. In summary, the combined therapy involving Ato and CQ addresses the inherent limitations of conventional ROS therapy, which include insufficient ROS production and increased autophagy. This approach holds significant potential as a treatment strategy for drug-resistant triple-negative breast cancer.

Reduction of Doxorubicin-Induced Cardiotoxicity by Co-Administration of Smart Liposomal Doxorubicin and Free Quercetin: In Vitro and In Vivo Studies

Doxorubicin is one of the most effective chemotherapeutic agents; however, it has various side effects, such as cardiotoxicity. Therefore, novel methods are needed to reduce its adverse effects. Quercetin is a natural flavonoid with many biological activities. Liposomes are lipid-based carriers widely used in medicine for drug delivery. In this study, liposomal doxorubicin with favorable characteristics was designed and synthesized by the thin-film method, and its physicochemical properties were investigated by different laboratory techniques. Then, the impact of the carrier, empty liposomes, free doxorubicin, liposomal doxorubicin, and quercetin were analyzed in animal models. To evaluate the interventions, measurements of cardiac enzymes, oxidative stress and antioxidant markers, and protein expression were performed, as well as histopathological studies. Additionally, cytotoxicity assay and cellular uptake were carried out on H9c2 cells. The mean size of the designed liposomes was 98.8 nm, and the encapsulation efficiency (EE%) was about 85%. The designed liposomes were anionic and pH-sensitive and had a controlled release pattern with excellent stability. Co-administration of liposomal doxorubicin with free quercetin to rats led to decreased weight loss, creatine kinase (CK-MB), lactate dehydrogenase (LDH), and malondialdehyde (MDA), while it increased the activity of glutathione peroxidase, catalase, and superoxide dismutase enzymes in their left ventricles. Additionally, it changed the expression of NOX1, Rac1, Rac1-GTP, SIRT3, and Bcl-2 proteins, and caused tissue injury and cell cytotoxicity. Our data showed that interventions can increase antioxidant capacity, reduce oxidative stress and apoptosis in heart tissue, and lead to fewer complications. Overall, the use of liposomal doxorubicin alone or the co-administration of free doxorubicin with free quercetin showed promising results.

Proton-mediated burst of dual-drug loaded liposomes for biofilm dispersal and bacterial killing

Exposure of infectious biofilms to dispersants induces high bacterial concentrations in blood that may cause sepsis. Preventing sepsis requires simultaneous biofilm dispersal and bacterial killing. Here, self-targeting DCPA(2-(4-((1,5-bis(octadecenoyl)1,5-dioxopentan-2-yl)carbamoyl)pyridin-1-ium-1-yl)acetate) liposomes with complexed water were self-assembled with ciprofloxacin loaded in-membrane and PEGylated as a lipid-membrane component, together with bromelain loaded in-core. Inside biofilms, DCPA-H₂O and PEGylated ciprofloxacin became protonated, disturbing the balance in the lipid-membrane to cause liposome-burst and simultaneous release of bromelain and ciprofloxacin. Simultaneous release of bromelain and ciprofloxacin enhanced bacterial killing in Staphylococcus aureus biofilms as compared with free bromelain and/or ciprofloxacin. After tail-vein injection in mice, liposomes accumulated inside intra-abdominal staphylococcal biofilms. Subsequent liposome-burst and simultaneous release of bromelain and ciprofloxacin yielded degradation of the biofilm matrix by bromelain and higher bacterial killing without inducing septic symptoms as obtained by injection of free bromelain and ciprofloxacin. This shows the advantage of simultaneous release from liposomes of bromelain and ciprofloxacin inside a biofilm.

Modeling Polyzwitterion-Based Drug Delivery Platforms: A Perspective of the Current State-of-the-Art and Beyond

Drug delivery platforms are anticipated to have biocompatible and bioinert surfaces. PEGylation of drug carriers is the most approved method since it improves water solubility and colloid stability and decreases the drug vehicles’ interactions with blood components. Although this approach extends their biocompatibility, biorecognition mechanisms prevent them from biodistribution and thus efficient drug transfer. Recent studies have shown (poly)zwitterions to be alternatives for PEG with superior biocompatibility. (Poly)zwitterions are super hydrophilic, mainly stimuli-responsive, easy to functionalize and they display an extremely low protein adsorption and long biodistribution time. These unique characteristics make them already promising candidates as drug delivery carriers. Furthermore, since they have highly dense charged groups with opposite signs, (poly)zwitterions are intensely hydrated under physiological conditions. This exceptional hydration potential makes them ideal for the design of therapeutic vehicles with antifouling capability, i.e., preventing undesired sorption of biologics from the human body in the drug delivery vehicle. Therefore, (poly)zwitterionic materials have been broadly applied in stimuli-responsive “intelligent” drug delivery systems as well as tumor-targeting carriers because of their excellent biocompatibility, low cytotoxicity, insignificant immunogenicity, high stability, and long circulation time. To tailor (poly)zwitterionic drug vehicles, an interpretation of the structural and stimuli-responsive behavior of this type of polymer is essential. To this end, a direct study of molecular-level interactions, orientations, configurations, and physicochemical properties of (poly)zwitterions is required, which can be achieved via molecular modeling, which has become an influential tool for discovering new materials and understanding diverse material phenomena. As the essential bridge between science and engineering, molecular simulations enable the fundamental understanding of the encapsulation and release behavior of intelligent drug-loaded (poly)zwitterion nanoparticles and can help us to systematically design their next generations. When combined with experiments, modeling can make quantitative predictions. This perspective article aims to illustrate key recent developments in (poly)zwitterion-based drug delivery systems. We summarize how to use predictive multiscale molecular modeling techniques to successfully boost the development of intelligent multifunctional (poly)zwitterions-based systems.

Recent Advances in Asialoglycoprotein Receptor and Glycyrrhetinic Acid Receptor-Mediated and/or pH-Responsive Hepatocellular Carcinoma- Targeted Drug Delivery

BACKGROUND

Hepatocellular carcinoma (HCC) seriously affects human health, especially, it easily develops multi-drug resistance (MDR) which results in treatment failure. There is an urgent need to develop highly effective and low-toxicity therapeutic agents to treat HCC and to overcome its MDR. Targeted drug delivery systems (DDS) for cancer therapy, including nanoparticles, lipids, micelles and liposomes, have been studied for decades. Recently, more attention has been paid to multifunctional DDS containing various ligands such as polymer moieties, targeting moieties, and acid-labile linkages. The polymer moieties such as poly(ethylene glycol) (PEG), chitosan (CTS), hyaluronic acid, pullulan, poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO) protect DDS from degradation. Asialoglycoprotein receptor (ASGPR) and glycyrrhetinic acid receptor (GAR) are most often used as the targeting moieties, which are overexpressed on hepatocytes. Acid-labile linkage, catering for the pH difference between tumor cells and normal tissue, has been utilized to release drugs at tumor tissue.

OBJECTIVES

This review provides a summary of the recent progress in ASGPR and GAR-mediated and/or pH-responsive HCC-targeted drug delivery.

CONCLUSION

The multifunctional DDS may prolong systemic circulation, continuously release drugs, increase the accumulation of drugs at the targeted site, enhance the anticancer effect, and reduce side effects both in vitro and in vivo. But it is rarely used to investigate MDR of HCC; therefore, it needs to be further studied before going into clinical trials.

Nanoplatforms for Targeted Stimuli-Responsive Drug Delivery: A Review of Platform Materials and Stimuli-Responsive Release and Targeting Mechanisms

To achieve the promise of stimuli-responsive drug delivery systems for the treatment of cancer, they should (1) avoid premature clearance; (2) accumulate in tumors and undergo endocytosis by cancer cells; and (3) exhibit appropriate stimuli-responsive release of the payload. It is challenging to address all of these requirements simultaneously. However, the numerous proof-of-concept studies addressing one or more of these requirements reported every year have dramatically expanded the toolbox available for the design of drug delivery systems. This review highlights recent advances in the targeting and stimuli-responsiveness of drug delivery systems. It begins with a discussion of nanocarrier types and an overview of the factors influencing nanocarrier biodistribution. On-demand release strategies and their application to each type of nanocarrier are reviewed, including both endogenous and exogenous stimuli. Recent developments in stimuli-responsive targeting strategies are also discussed. The remaining challenges and prospective solutions in the field are discussed throughout the review, which is intended to assist researchers in overcoming interdisciplinary knowledge barriers and increase the speed of development. This review presents a nanocarrier-based drug delivery systems toolbox that enables the application of techniques across platforms and inspires researchers with interdisciplinary information to boost the development of multifunctional therapeutic nanoplatforms for cancer therapy.

Synthesis, conjugating capacity and biocompatibility evaluation of a novel amphiphilic polynorbornene

Polynorbornenes, prepared by the ‘living’ and ‘controlled’ ring-opening metathesis polymerization (ROMP) method, have emerged as a stimuli-sensitive new class of polymer carriers. Herein, we reported a novel amphiphilic diblock polynorbornene, PNCHO-b-PNTEG, containing active benzaldehyde units, which exhibited good conjugating capacity to amino-containing molecules (e.g., doxorubicin (DOX)) via the pH-sensitive Schiff base linkage. The copolymer and its conjugate with DOX, DOX-PNCHO-b-PNTEG, were adequately analyzed by various techniques including ¹H NMR, ¹³C NMR, gel permeation chromatography, etc. Especially, the formed conjugate of DOX-PNCHO-b-PNTEG could self-assemble into near-spherical micelles with the diameter of 81 ± 10 nm, and exhibit acid-triggered DOX release behavior, and the release rate could be adjusted by changing the environmental pH value. The excellent biological safety of PNCHO-b-PNTEG was further demonstrated by the results from both in vitro toxicity evaluation to murine fibroblast cells (L-929 cells) and in vivo evaluation of acute developmental toxicity and cell death in zebrafish embryos. Hence, the present polynorbornene-based PNCHO-b-PNTEG possesses great potential application as a biocompatible polymeric carrier and could be employed to fabricate various pH-sensitive conjugates.

Stealth Coating of Nanoparticles in Drug-Delivery Systems

Nanoparticles (NPs) have emerged as a powerful drug-delivery tool for cancer therapies to enhance the specificity of drug actions, while reducing the systemic side effects. Nonetheless, NPs interact massively with the surrounding physiological environments including plasma proteins upon administration into the bloodstream. Consequently, they are rapidly cleared from the blood circulation by the mononuclear phagocyte system (MPS) or complement system, resulting in a premature elimination that will cause the drug release at off-target sites. By grafting a stealth coating layer onto the surface of NPs, the blood circulation half-life of nanomaterials can be improved by escaping the recognition and clearance of the immune system. This review focuses on the basic concept underlying the stealth behavior of NPs by polymer coating, whereby the fundamental surface coating characteristics such as molecular weight, surface chain density as well as conformations of polymer chains are of utmost importance for efficient protection of NPs. In addition, the most commonly used stealth polymers such as poly(ethylene glycol) (PEG), poly(2-oxazoline) (POx), and poly(zwitterions) in developing long-circulating NPs for drug delivery are also thoroughly discussed. The biomimetic strategies, including the cell-membrane camouflaging technique and CD47 functionalization for the development of stealth nano-delivery systems, are highlighted in this review as well.

Development of 11-DGA-3-O-Gal-Modified Cantharidin Liposomes for Treatment of Hepatocellular Carcinoma

Background: Liver cancer is a common malignant tumor worldwide, and its morbidity and mortality increase each year. The disease has a short course and high mortality, making it a serious threat to human health. Purpose: The objective of this study was to create novel liver-targeting nanoliposomes to encapsulate cantharidin (CTD) as a potential treatment for hepatic carcinoma. Methods: 3-Galactosidase-30-stearyl deoxyglycyrrhetinic acid (11-DGA-3-O-Gal)-modified liposomes (11-DGA-3-O-Gal-CTD-lip) for the liver-targeted delivery of CTD were prepared via the film-dispersion method and characterized. In vitro analyses of the effects on cellular cytotoxicity, cell migration, cell cycle, and cell apoptosis were carried out and an in vivo pharmacokinetics study and tissue distribution analysis were performed. Results: Compared with unmodified liposomes (CTD-lip), 11-DGA-3-O-Gal-CTD-lip showed higher cytotoxicity and increased the inhibition of HepG2 cell migration, but they did not increase the apoptotic rate of cells. The inhibition mechanism of 11-DGA-3-O-Gal-CTD-lip on hepatocellular carcinoma was partly through cell cycle arrest at the S phase. Analysis of pharmacokinetic parameters indicated that 11-DGA-3-O-Gal-CTD-lip were eliminated more rapidly than CTD-lip. Regarding tissue distribution, the targeting efficiency of 11-DGA-3-O-Gal-CTD-lip to the liver was (41.15 ± 3.28)%, relative targeting efficiency was (1.53 ± 0.31)%, relative uptake rate was( 1.69 ± 0.37)%, and peak concentration ratio was (2.68 ± 0.12)%. Conclusion: 11-DGA-3-O-Gal-CTD-lip represent a promising nanocarrier for the liver-targeted delivery of antitumor drugs to treat hepatocellular carcinoma.

The role of nanoparticles in the improvement of systemic anticancer drug delivery

The systemic delivery of drugs to the body via circulation after oral administration is a preferred method of drug administration during cancer treatment given its ease of implementation. However, the physicochemical properties of many current anticancer drugs limit their effectiveness when delivered by systemic routes. The use of nanoparticles (NPs) has emerged as an effective means of overcoming the inherent limitations of systemic drug delivery. We provide herein an overview of various NP formulations that facilitate improvements in the efficacy of various anticancer drugs compared with the free drug. This review will be useful to the reader who is interested in the role NP technology is playing in shaping the future of chemotherapeutic drug delivery and disease treatment.

Glycyrrhizic acid as a multifunctional drug carrier - From physicochemical properties to biomedical applications: A modern insight on the ancient drug

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Glycyrrhizic acid (GA), saponin of licorice shows wide range of biological activity.

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Mechanism of GA activity on the cell and molecular level is rarely discussed.

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GA activity could be caused by the cell membrane modification.

Glycyrrhizic acid is the main active component of Licorice root which has been known in traditional Chinese and Japanese medicine since ancient times. In these cultures glycyrrhizic acid (GA) is one of the most frequently used drugs. However, only in 21-st century a novel unusual property of the GA to enhance the activity of other drugs has been discovered. The review describes briefly the experimental evidences of wide spectrum of own biological activities of glycyrrhizic acid as well as discusses the possible mechanisms of the ability of GA to enhance the activity of other drugs. We have shown that due to its amphiphilic nature GA is able to form self-associates in aqueous and non-aqueous media, as well as water soluble complexes with a wide range of lipophilic drugs. The main purpose of our review is to focus reader's attention on physicochemical studies of the molecular mechanisms of GA activity as a drug delivery system (DDS). In our opinion, the most intriguing feature of glycyrrhizic acid which might be the key factor in its therapeutic activity is the ability of GA to incorporate into the lipid bilayer and to increase the membrane fluidity and permeability. The ability of biomolecules and their aggregates to change the properties of cell membranes is of great significance, from both fundamental and practical points of view.

Eph A10-modified pH-sensitive liposomes loaded with novel triphenylphosphine-docetaxel conjugate possess hierarchical targetability and sufficient antitumor effect both in vitro and in vivo

Mitochondrial-targeting therapy was considered to be a promising approach for the efficient treatment of cancer while positive charge induced nonspecific cytotoxicity severely limits its application. To overcome this drawback, a novel mitochondria targeted conjugate triphenylphosphine-docetaxel (TD) has been synthesized successfully and incorporated it into liposomes (EPSLP/TD), which possessed excellent pH-sensitive characteristic, EphA 10 mediated active targetability as well as mitochondria-targeting capability. EPSLP/TD was characterized to have a small particle size, high-encapsulation efficiency and excellent pH-sensitive characteristic. Compared with DTX-loaded liposomes (EPSLP/DTX), EPSLP/TD possessed higher cytotoxicity against MCF-7 cell line. Mitochondrial-targeting assay demonstrated mitochondria-targeting moiety triphenylphosphine (TPP) could efficiently deliver DTX to mitochondria. Western immunoblotting assay indicated that EPSLP/TD could efficiently deliver antitumor drug to mitochondria and induce cell apoptosis via mitochondria-mediated apoptosis pathway. In vivo antitumor study demonstrated EPSLP/TD owed excellent in vivo antitumor activity. Histological assay demonstrated EPSLP/TD showed strongly apoptosis inducing effect, anti-proliferation effect and anti-angiogenesis effect. This work investigated the potential of hierarchical targeting pH-sensitive liposomes is a suitable carrier to activate mitochondria-mediated apoptosis pathway for cancer therapy.

Overcoming Multidrug Resistance by Codelivery of MDR1-Targeting siRNA and Doxorubicin Using EphA10-Mediated pH-Sensitive Lipoplexes: In Vitro and In Vivo Evaluation

The therapeutic efficacy of chemotherapy is dramatically hindered by multidrug resistance (MDR), which is induced by the overexpression of P-glycoprotein (P-gp). The codelivery of an antitumor drug and siRNA is an effective strategy recently applied in overcoming P-gp-related MDR. In this study, a multifunctional drug delivery system with both pH-sensitive feature and active targetability was designed, in which MDR1-siRNA and DOX were successfully loaded. The resulting carrier EphA10 antibody-conjugated pH-sensitive doxorubicin (DOX), MDR1-siRNA coloading lipoplexes (shortened as DOX + siRNA/ePL) with high serum stability had favorable physicochemical properties. DOX + siRNA/ePL exhibited an incremental cellular uptake, enhanced P-gp downregulation efficacy, as well as a better cell cytotoxicity in human breast cancer cell line/adriamycin drug-resistant (MCF-7/ADR) cells. The results of the intracellular colocalization study indicated that DOX + siRNA/ePL possessed the ability for pH-responsive rapid endosomal escape in a time-dependent characteristic. Meanwhile, the in vivo antitumor activities suggested that DOX + siRNA/ePL could prolong the circulation time as well as specifically accumulate in the tumor cells via receptor-mediated endocytosis after intravenous administration into the blood system. The histological study further demonstrated that DOX + siRNA/ePL could inhibit the proliferation, induce apoptosis effect, and downregulate the P-gp expression in vivo. Altogether, DOX + siRNA/ePL was expected to be a suitable codelivery system for overcoming the MDR effect.

Synthesis, characterization and in vitro/in vivo evaluation of novel reduction-sensitive hybrid nano-echinus-like nanomedicine

To remedy the problems resulting from the usage of anti-cancer drugs in cancer chemotherapy, such as deficient drug concentration in tumour cells, low water-solubility and non-specific distribution of antitumour drugs, a kind of reduction-sensitive polymer prodrug of curcumin (Cur) containing in the nano-echinus was synthesized and designed. The nano-echinus-like nanomedicine presented synergistic effect with glycyrrhetic acid (GA) and oligomeric hyaluronic (HA) for targeting and combating HepG2 human liver cancer cell. Firstly, a kind of small molecular prodrug of Cur, dithiodipropionic acid-Cur (-SS-Cur), was chemically conjugated onto the side chain of the conjugated glycyrrhetic acid- oligomeric hyaluronic (GA-HA) to generate an amphiphilic polymeric prodrug of Cur, GA-HA-SS-Cur. The obtained GA-HA-SS-Cur prodrug and subsidiary material mPEG-DSPE could self-assemble into a sea urchin-like micelles in aqueous media and release Cur rapidly in response to glutathion (GSH). Then, Cur was loaded into the nano-echinus with a particle size of (118.1 ± 0.2 nm) and drug-loading efficiency of (8.03 ± 2.1%). The structure of GA-HA-SS-Cur was characterized by ¹H-NMR in this report. The morphology of micelles was observed with a transmission electron microscope (TEM). Subsequently, the reduction-sensitivity of the nano-echinus was confirmed by the changes in in-vitro drug release after different concentrations of GSH treatment. Besides, the cellular uptake behaviour and MTT assays of the nano-echinus were investigated, suggesting that the nano-echinus was of desirable safety and could be taken into HepG2 cells in a time-dependent manner. Later, anti-tumour efficacy in vivo revealed the effective inhibition of tumour growth.

Cellular uptake mechanism and clearance kinetics of fluorescence-labeled glycyrrhetinic acid and glycyrrhetinic acid-modified liposome in hepatocellular carcinoma cells

Glycyrrhetinic acid (GA) is a natural pentacyclic triterpene derivative that exerts significant effects in the suppression of liver cancer. The receptors of GA on liver cells and hepatocellular carcinoma (HCC) cells have drawn broad attention. The effects of GA might depend on its transport into and out of cells. However, the question has not been previously addressed despite its obvious and fundamental importance. In this paper, GA and GA-modified liposome (GA-Lip) were labeled with fluorescein isothiocyanate (FITC) or coumarin 6 (Cou6) using chemical or pharmaceutical techniques. The transport courses of FITC-GA and GA-Cou6-Lip were studied in HepG2 cells in vitro. We found that the fluorescence labeled GA and GA-Lip uptake and clearance were time-dependent. FITC-GA uptake involved passive diffusion and active transport, and the receptors were in the cytomembrane proteins. GA-Cou6-Lip uptake was mediated by caveolae-dependent endocytosis. In addition, FITC-GA and GA-Cou6-Lip clearance of the HCC cells fitted exponential decay and second-order processes, respectively. These findings provide new insights into the anti-HCC actions of GA.

Preparation and properties evaluation of a novel pH-sensitive liposomes based on imidazole-modified cholesterol derivatives

As a new kind of drug carries, pH-sensitive liposomes have been widely studied in tumor therapy for their advantages of target ability and sustained-release. Here, we synthesized a pH-sensitive material, N-(3-Aminopropyl)imidazole-cholesterol (IM-Chol) and prepared a novel pH-sensitive liposomes using IM-Chol and phosphatidylcholine. IM-Chol was synthesized through amidation reaction between the amino group of N-(3-Aminopropyl)imidazole and acyl chloride group of cholesteryl chloroformate in a weak base solution. Optimal conditions to prepare liposomes were obtained by the orthogonal experiment with the higher encapsulation efficiency as the evaluation indicator. The properties of liposomes, such as particle size, zeta potential, morphology, encapsulation efficiency, drug release behavior and in vitro cell toxicity were evaluated by transmission electron microscopy (TEM), dynamic light scattering (DLS) and MTT assay respectively. The results showed that the average particle size of IM-Chol liposomes was 141nm (PDI 0.323). Liposomes can assemble into uniform spheres at pH 7.4, but under the condition of pH 5.0, the spherical structure of IM-Chol liposomes was broken, exhibiting pH-sensitive property. In vitro drug releasing studies demonstrated the controlled-release behavior of the curcumin (CUR) in the IM-Chol liposomes. The cumulative release of CUR reached to 72.5% in the first 24h at pH 5.0, faster than that at pH 7.4, which confirmed that the drug carrier displayed pH-sensitive release behaviors. In addition, the MTT assay was employed to test the cytotoxicity of IM-Chol liposomes and CUR IM-Chol liposomes. All cell viabilities were greater than 80% after incubating for 24h, even up to the highest dose of 500mg/L, indicating that IM-Chol liposomes had good biocompatibility. The tumor inhibitory results towards EC109 cells of free CUR and CUR-loaded IM-Chol liposomes indicated that IM-Chol liposomes indeed enhanced the cell killing effect of CUR. These results showed that the novel IM-Chol liposomes prepared in this paper had pH-sensitive property and were expected to play a huge potential in tumor treatment.

pH-responsive Virus-like Nanoparticles with Enhanced Tumour-targeting Ligands for Cancer Drug Delivery

Multifunctional nanocarriers harbouring specific targeting moieties and with pH-responsive properties offer great potential for targeted cancer therapy. Several synthetic drug carriers have been studied extensively as drug delivery systems but not much information is available on the application of virus-like nanoparticles (VLNPs) as multifunctional nanocarriers. Here, we describe the development of pH-responsive VLNPs, based on truncated hepatitis B virus core antigen (tHBcAg), displaying folic acid (FA) for controlled drug delivery. FA was conjugated to a pentadecapeptide containing nanoglue bound on tHBcAg nanoparticles to increase the specificity and efficacy of the drug delivery system. The tHBcAg nanoparticles loaded with doxorubicin (DOX) and polyacrylic acid (PAA) demonstrated a sustained drug release profile in vitro under tumour tissue conditions in a controlled manner and improved the uptake of DOX in colorectal cancer cells, leading to enhanced antitumour effects. This study demonstrated that DOX-PAA can be packaged into VLNPs without any modification of the DOX molecules, preserving the pharmacological activity of the loaded DOX. The nanoglue can easily be used to display a tumour-targeting molecule on the exterior surface of VLNPs and can bypass the laborious and time-consuming genetic engineering approaches.

Polyethyleneimine-stabilized hydroxyapatite nanoparticles modified with hyaluronic acid for targeted drug delivery

Preparation of polyethyleneimine stabilized hydroxyapatite nanoparticles modified with hyaluronic acid for targeted drug delivery.

Co-delivery of doxorubicin and the traditional Chinese medicine quercetin using biotin–PEG2000–DSPE modified liposomes for the treatment of multidrug resistant breast cancer

At present, multidrug resistance (MDR) in cancer therapy is an international problem, which is caused mostly by the overexpressed P-glycoprotein (P-gp) efflux pump.