Cellular Vehicles Based on Neutrophils Enable Targeting of Atherosclerosis.

Given the multiple interactions between neutrophils (NEs) and atherosclerosis (AS), in this study, we exploited NEs as cellular vehicles loaded with cationic liposomes for actively targeting atherosclerotic sites. The cellular vehicles based on NEs possess efficient internalization of cationic liposomes and sensitive response to the chemotaxis of atherosclerotic inflammatory cells, which ultimately realize the targeted delivery of the cargos into the target cells in vitro. Moreover, these effects also translated to significant enhancement of the accumulation of NEs' cargos into the atherosclerotic plaque in vivo after administering NE vehicles to the AS animal model. Consequently, cellular vehicles based on NEs could be a novel strategy for targeted delivery of payloads into atherosclerotic plaque, which would facilitate theranostics for AS and the development of anti-AS drugs to manage the disease.

A Collaborative Assembly Strategy for Tumor-Targeted siRNA Delivery.

A novel "collaborative assembly" approach was reported for the synthesis of an siRNA delivery system via a combination of an electrostatically driven physical assembly and a facile click reaction-mediated chemical assembly, which showed various advantages of more safety, efficiency, and flexibility over the conventional approach that is only based on the physical assembly. This strategy remained a high cationic property of lipid-based complex for high siRNA loading capacity. The direct chemical modification of a model polyanion, hyaluronic acid (HA) on the cationic complex via click chemistry shielded the positive charge of complex without affecting the siRNA binding, which reduced the toxicity and enhanced the blood stability of the complex. In addition, the incorporated polyanion might be prefunctionalized, which endued the carrier with better biological characteristics such as long circulating or tumor targeting. We demonstrated that the obtained lipid-polymer hybrid nanoparticle (RSC-HA) using collaborative assembly presented greater in vivo stability in the blood for efficient tumor targeting than the physically assembled RSC/HA in which HA was physically adsorbed on the complex. After endocytosis into the cells, the protection of RSC-HA on siRNA turned off, while the release of siRNA induced by the intracellular signals for enhanced gene-silencing capacity. This combination of physical and chemical assemblies provides an efficient strategy for the exploitation of safe, stable, and functionalized siRNA delivery systems.

Lactoferrin-modified poly(ethylene glycol)-grafted BSA nanoparticles as a dual-targeting carrier for treating brain gliomas.

In this study, a dual-targeting drug delivery system based on bovine serum albumin nanoparticles (BSA-NPs) modified with both lactoferrin (Lf) and mPEG2000 loading doxorubicin (DOX) was designed, and its blood-brain barrier (BBB) penetration and brain glioma cells targeting properties were explored. BSA-NPs were prepared by a desolvation technique, and mPEG2000 was incorporated onto the surface of BSA-NPs by reacting with the free amino-group of BSA to form mPEG2000-modified BSA-NPs (P2000-NPs). Finally, Lf-modified P2000-NPs (Lf-NPs) was obtained by absorbing Lf onto the surface of P2000-NPs via the positive and negative charges interaction at physiological pH. Three levels of mPEG2000 and Lf-modified NPs were prepared and characterized, respectively. The uptake and potential cytotoxicity of different DOX preparations in vitro by the primary brain capillary endothelial cells (BCECs) and glioma cells (C6) were investigated. The dual-targeting effects were studied on the BBB model in vitro, BCECs/C6 glioma coculture model in vitro, and C6 glioma-bearing rats in vivo, respectively. The results exhibited that, with the increase of the amount of both mPEG2000 and Lf, the particle size of NPs increased and its zeta potential decreased. The in vivo pharmacokinetics study in healthy rats exhibited that P2000-NPs with a high level of mPEG2000 (P2000H-NPs) had longer circulation time in vivo. Compared to other NPs, Lf-NPs with high level of both Lf and mPEG2000 (LfH-NPs) showed the strongest cytotoxicity and the highest effectiveness in the uptake both in BCECs and C6 as well as improved the dual-targeting effects. Body distribution of DOX in different formulations revealed that LfH-NPs could significantly increase the accumulation of DOX in the brain, especially at 2 h postinjection (P < 0.05). In conclusion, Lf-NPs were a prospective dual-targeting drug delivery system for effective targeting therapy of brain gliomas.

An elastase-inhibiting, plaque-targeting and neutrophil-hitchhiking liposome against atherosclerosis.

Neutrophil extracellular traps (NETs) play a crucial role in the formation of vulnerable plaques and the development of atherosclerosis. Alleviating the pathological process of atherosclerosis by efficiently targeting neutrophils and inhibiting the activity of neutrophil elastase to inhibit NETs is relatively unexplored and is considered a novel therapeutic strategy with clinical significance. Sivelestat (SVT) is a second-generation competitive inhibitor of neutrophil elastase with high specificity. However, therapeutic effect of SVT on atherosclerosis is restricted because of the poor half-life and the lack of specific targeting. In this study, we construct a plaque-targeting and neutrophil-hitchhiking liposome (cRGD-SVT-Lipo) to improve the efficacy of SVT in vivo by modifying the cRGD peptide onto SVT loaded liposome, which was based on the interaction between cRGD peptide and integrin ανß3 on the surface of cells in blood and plaque, including epithelial cell, macrophage and neutrophils. The cRGD-SVT-Lipo could actively tend to or hitchhike neutrophils in situ to reach atherosclerotic plaque, which resulted in enhanced atherosclerotic plaque delivery. The cRGD-SVT-Lipo could also reduce plaque area, stabilize plaque, and ultimately alleviate atherosclerosis progression through efficiently inhibiting the activity of neutrophil elastase in atherosclerotic plaque. Therefore, this study provides a basis and targeting strategy for the treatment of neutrophil-related diseases. STATEMENT OF SIGNIFICANCE: Neutrophil extracellular traps (NETs)-inhibiting is a prospective therapeutic approach for atherosclerosis but has received little attention. The NETs can be inhibited by elastase-restraining. In this work, an intriguing system that delivers Sivelestat (SVT), a predominantly used neutrophil elastase inhibitor with poor targeting capability, is designed to provide the drug with plaque-targeting and neutrophil-hitchhiking capability. The result suggests that this system can effectively hinder the formation of NETs and delay the progression of atherosclerosis.

LNP-mRNA vaccine prevents type 1 diabetes in non-obese diabetes mice.

Islet-antigen-specific tolerization is a key goal of experimental immunotherapies for type 1 diabetes. mRNA-based vaccines have demonstrated the feasibility of RNA delivery in inducing antigen tolerance in autoimmune diseases. In this study, mRNA vaccine, encoded tandem glutamic acid decarboxylase 65 (GAD65) epitopes and cholera toxin B subunit (CTB-GADIII), prepared by an in vitro transcription (IVT) system and encapsulated with lipid nanoparticles (LNP), was intramuscularly administered to non-obese diabetic (NOD) and cyclophosphamide (Cy)-NOD mice respectively. The results showed that the mRNA vaccines significantly reduced the incidence rate of type 1 diabetes, delayed the disease progression, improved glucose tolerance, and protected pancreatic morphology and function compared with the controls. Meanwhile, the vaccines also reduced the levels of autoantibodies to glutamic acid decarboxylase (GADA) and insulin (IAA) in the serum. Furthermore, the proportion of CD4+ T helper cell subsets was modulated in the spleen of mice treated with mRNA vaccines, in correspondence with the increased levels of IL-10 and TGF-ß in serum, suggesting the possible mechanism of immune tolerance. This study provides experimental evidence for the application of mRNA vaccines encoding self-antigens in the prevention or treatment of type 1 diabetes.

Multistep targeted nano drug delivery system aiming at leukemic stem cells and minimal residual disease.

Refractory leukemia remains the most common therapeutic problem in clinical treatment of leukemia. The key therapy of refractory leukemia is to kill, thoroughly, the minimal residual disease and leukemia stem cells in the highly vascularized red marrow areas. In this study, two new conjugates, alendronate-polyethylene glycol (100) monostearate and folate-polyethylene glycol (100) monostearate, were synthesized to develop a multistep targeting nanostructured lipid carriers by enhancing drug transport to the high bone turnover areas adjacent to the red marrow and targeting the minimal residual disease and leukemia stem cells. This dual targeting system demonstrated a great binding affinity to hydroxyapatite, a model component of bone minerals, and higher cell uptake (in the form of carriers but not drug) and cytotoxicity in the K562 cell line, a leukemia cell line with overexpressed folate receptors, were observed in vitro compared to unmodified carriers, especially when the cells were pretreated and the receptors were up-regulated by all-trans retinoic acid. The comodel test of K562 cells and HA showed that this dual targeting system could desorb from bone surface and be taken up by leukemia cells. For the in vivo study, this dual targeting system exhibited a significant increase in plasma half-life and could specifically accumulate in the bone tissue of rats or mice after intravenous injection. Ex vivo imaging of mice femurs and confocal laser scanning microscope imaging of mice femur slices further confirmed that this dual targeting system could favorably deposit to the osteoblast-enriched areas of high bone turnover in regions of trabecular bone surrounded by red marrow. In vivo antitumor activity in K562/BALB/c-nu leukemia mice showed that the treatment of this dual targeting system significantly reduced the white blood cell (WBC) number in peripheral blood and bone marrow to the normal level. In conclusion, this dual targeting system could precisely target to the regions where the minimal residual disease and leukemia stem cells are located and then be specifically uptaken in large amounts, which is a valuable target for refractory leukemia therapy.

Mitochondrial-targeted brequinar liposome boosted mitochondrial-related ferroptosis for promoting checkpoint blockade immunotherapy in bladder cancer.

Checkpoint blockade immunotherapy (CBI) have exhibited remarkable benefits for cancer therapy. However, the low responsivity of CBI hinders its application in treatment of bladder cancer. Ferroptosis shows potential for increasing the responsivity of CBI by inducing immunogenic cell death (ICD) process. Herein, we developed a mitochondrial-targeted liposome loaded with brequinar (BQR) (BQR@MLipo) for enhancing the mitochondrial-related ferroptosis in bladder cancer in situ. It could be found that BQR@MLipo could selectively accumulate into mitochondria and inactivate dihydroorotate dehydrogenase (DHODH), which induced extensive mitochondrial lipid peroxidation and ROS, finally triggering ferroptosis of bladder cancer cells to boost the release of intracellular damage-associated molecular patterns (DAMPs) such as calreticulin (CRT), adenosine triphosphate (ATP), high mobility group box 1 (HMGB1). In addition, BQR@MLipo further promoted the release of mtDNA into the cytoplasm to activate the cGAS-STING pathway for the secretion of IFN-ß, which would increase the cross-presentation of antigens by dendritic cells and macrophage phagocytosis. Furthermore, the in vivo studies revealed that BQR@MLipo could remarkably accumulate into the bladder tumor and successfully initiate the infiltration of CD8+ T cells into tumor microenvironment for enabling efficient CBI to inhibit bladder tumor growth. Therefore, BQR@MLipo may represent a clinically promising modality for enhancing CBI in bladder tumor.

Nano-sponge-like liposomes remove cholesterol crystals for antiatherosclerosis.

Atherosclerotic cardiovascular diseases remain the leading causes of morbidity and mortality worldwide. Cholesterol crystals in atherosclerotic plaques play an essential role in atherosclerosis progression. However, no clinical drugs have been used for removing cholesterol crystals from plaque to counter atherosclerosis. Previous studies identified the hydrophobic domain of lipid bilayer in liposomes acted as sinks for solubilizing hydrophobic cholesterol. Moreover, adjusting the composition of the lipid bilayer in liposomes can enhance its hydrophobic molecule loading capacity. Therefore, in this study, ginsenosides Rb1 (Rb1), one of main active components of ginseng which has a similar structure to cholesterol, is anchored into soy phospholipids bilayer with its hydrophobic region to prepare nano-sponge-like liposomes (Rb1-LPs), aiming to amplify the solubilization of cholesterol in lipid bilayer. For targeting delivery to atherosclerotic plaques, Annexin V (AnxV), a protein that can specifically recognize phosphatidylserine upregulated in atherosclerotic plaques, is applied to decorate the surface of Rb1-LPs by click reaction to obtain the final preparation of AnxV-Rb1-LPs. The in vitro studies showed that incorporating Rb1 into lipid bilayer remarkably increased the affinity of the lipid bilayer to free cholesterol and the solubilization of cholesterol crystals. Additionally, nano-sponge-like liposomes could efficiently reduce the accumulation of cholesterol crystals and improve cholesterol efflux, finally inhibiting inflammation and apoptosis in cholesterol-laden cells. Furthermore, AnxV-Rb1-LPs could efficiently accumulate in atherosclerotic plaques after intravenous injection, exert nano-sponge-like functions to remove intra- and extracellular cholesterol crystals, ultimately alleviating inflammation and apoptosis in atherosclerotic plaques for antiatherosclerosis. Therefore, AnxV-Rb1-LPs provide a potential strategy for removing cholesterol crystals in atherosclerotic plaques and can be further utilized in other diseases with excessive cholesterol accumulation.

Effect of octreotide-polyethylene glycol(100) monostearate modification on the pharmacokinetics and cellular uptake of nanostructured lipid carrier loaded with hydroxycamptothecine.

A new conjugate, octreotide-polyethylene glycol(100) monostearate (OPMS), was developed for the enhancement of targeting delivery of hydroxycamptothecine (HCPT) loaded in nanostructured lipid carrier (NLC). 2 × 10(-3) and 5 × 10(-3) mmol of OPMS were respectively used to modify NLC so that the targeted nanocarriers with low and high ligand density were obtained. For comparison, the pegylated NLCs without octreotide were prepared by adding equal molar amounts of polyethylene glycol(100) monostearate (PGMS). The relation between the modification levels and properties of various NLCs were studied in vivo and in vitro. At a high modification level, a slower release rate of HCPT and the more stable nanocarriers was achieved. At the same time, the fixed aqueous layer thickness (FALT) and average surface density of PEG chains (SD(PEG)) was increased, but the distance (D) between two neighboring PEG grafting sites became narrower. The in vivo pharmacokinetic study in healthy rat indicated that the modified NLCs had a longer circulation than NLC (P < 0.05) due to pegylation effect and OPMS modified NLCs had larger MRT and AUC(0-t) than that of PGMS modified NLCs at the same modification level. Furthermore, the florescence microscopy observation also showed the targeting effect of octreotide modification on somatostatin receptors (SSTRs) of tumor cell (SMMC-7721). The uptake of SMMC-7721 was much more than that of normal liver cell (L02) for OPMS modified NLC, and the highest uptake was observed for 5 × 10(-3) mmol of OPMS modified one. No obvious difference was found among the L02 uptake of OPMS modified NLCs and NLC, but their uptake was higher than that of PGMS modified NLCs. All the results indicated that the OPMS highly modified NLCs would improve the effect of antitumor therapy by inhibiting the degradation, evading RES and enhancing the drug uptake of tumor cells.

Box-Behnken optimization design and enhanced oral bioavailability of thymopentin-loaded poly (butyl cyanoacrylate) nanoparticles.

This study was done to prepare thymopentin (TP5)-loaded poly (butyl cyanoacrylate) nanoparticles (TP5-PBCA-NPs) and evaluate thier efficacy for oral delivery. TP5-PBCA-NPs were prepared by emulsion polymerization, and the formulation was optimized based on Box-Behnken experimental design. The physico-chemical characteristics of TP5-PBCA-NPs were evaluated using transmission electron microscopy (TEM), malvern zetasizer, Fourier transform infra-red spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The encapsulation efficiency, enzymatic degradation and release behavior of TP5-PBCA-NPs in various media were evaluated using a high-performance liquid chromatography (HPLC) method. The pharmacodynamic studies on oral administration of TP5-PBCA-NPs were performed in FACScan flow cytometry. An optimum formulation consisted of 0.7% poloxamer 188 (Pol), 0.6% dextran-70 (Dex), 0.1% sodium metabisulfite (Sm), 0.1% TP5 and 1% (v/v) n-butyl cyanoacrylate. The particle size and zeta potential of optimized TP5-PBCA-NPs was 212 nm and -22.6 mV respectively with 82.45% encapsulation efficiency. TP5 was entrapped inside the nanoparticles in molecular dispersion form. The release of TP5 from PBCA-NPs was pH dependent; the cumulative release percentage in 0.1 M HCI for 4 hours was less than 16% while it was more than 80% in pH6.8 PBS. The PBCA-NPs could efficiently protect TP5 from enzymatic degradation; the remained percentage of TP5 encapsulated in PBCA-NPs was 58.40% after incubated with trypsin in pH6.8 PBS for 4 h while it was only 32.29% for free drug. In the oral administration study in vivo, the lowered T-lymphocyte subsets values were significantly increased and the raised CD4+/CD8+ ratio was evidently reduced compared with that of TP5 solution (p < 0.05), and the improvement of bioavailability was dose-dependent. These results indicated that the PBCA nanoparticles may be a promising carrier for oral delivery of TP5.

Octreotide-modification enhances the delivery and targeting of doxorubicin-loaded liposomes to somatostatin receptors expressing tumor in vitro and in vivo.

Octreotide is believed to be the ligand of somatostatin receptors (SSTRs) which are widely used in tumor diagnosis and clinical therapy. In the present work, a new targeting conjugate, octreotide-polyethylene glycol-phosphatidylethanolamine (Oct-PEG-PE), was developed for the assembling of liposome, and the effect of octreotide-modification on the enhancement of the delivery and targeting of doxorubicin-loaded liposomes was investigated in vitro and in vivo. Oct-PEG-PE was synthesized by a three-step reaction involving two derivative intermediate formations of bis (p-nitrophenyl carbonate)-PEG ((pNP)(2)-PEG) and pNP-PEG-PE. The Oct-modified and unmodified liposomes (DOX-OL and DOX-CL) were prepared by the ammonium sulfate gradient method. Both drug uptake assay and cell apoptosis assay suggested that DOX-OL noticeably increased the uptake of DOX in SMMC-7721 cells and showed a more significant cytotoxicity, compared with DOX-CL. The effect of DOX-OL was remarkably inhibited by free octreotide. In contrast, no significant difference in drug cytotoxicity was found between DOX-OL and DOX-CL in CHO cells without obvious expression of SSTRs. The study of ex vivo fluorescence tissues imaging of BALB/c mice and in vivo tissue distribution of B16 tumor-bearing mice indicated that DOX-OL caused remarkable accumulation of DOX in melanoma tumors and the pancreas, in which the SSTRs are highly expressed.

An apoptotic body-biomimic liposome in situ upregulates anti-inflammatory macrophages for stabilization of atherosclerotic plaques.

The macrophages mediated inflammation participates in every stage of atherosclerosis. Attenuation of macrophages inflammatory responses by active ingredients in atherosclerotic plaques is benefit to atherosclerotic stabilization and regression, but meanwhile, it is highly desired to develop accurate therapeutics for reducing off-target effects. Previous studies revealed that the apoptotic bodies are effectively recognized and engulfed by macrophages own to increased exposure of phosphatidylserine (PtdSer), which is regarded as a key "eat-me" signal. To achieve optimal delivery efficiency, an apoptotic body biomimic liposome (AP-Lipo) is constructed by decorating PtdSer and DSPE-PEG2000-cRGDfK onto the surface of liposome for selectively delivering pioglitazone (PIO), a peroxisome proliferator-activated receptor γ (PPARγ) agonist, into atherosclerotic macrophages while minimizing its side effects. Compared with unmodified liposome, AP-Lipo is more effective to recognize and penetrate the activated vascular endothelial monolayer, target pro-inflammatory macrophages and suppress the inflammation by upreglation of anti-inflammatory cytokines in vitro. Moreover, AP-Lipo can effectively target to atherosclerotic plaques and imped the progression of atherosclerosis by upregulating anti-inflammatory macrophages number and stabilizing the atherosclerotic plaques. In summary, this design imitates the characteristic of apoptotic body and provides a potential drug delivery system for atherosclerosis and other diseases, which attribute to inflammation mediated by macrophages.

Iron chelated melanin-like nanoparticles for tumor-associated macrophage repolarization and cancer therapy.

Tumor-associated macrophages (TAMs) are abundant in many cancers, and predominately display an immunosuppressive M2-like function that fosters tumor progression and promotes malignant metastasis. Current TAMs repolarization strategies mainly focused on harnessing the direct cancer cell killing property of M1-like macrophages repolarized from TAMs. However, the latent role of M1-like macrophages as professional antigen-presenting cells (APCs) also needs to be explored. Here, iron chelated melanin-like nanoparticles (Fe@PDA-PEG) were developed for M2-to-M1 TAMs repolarization and photothermal therapy (PTT) induced tumor-associated antigens (TAAs) releasing, which would exploit the potential of M1-like macrophages acquired as professional APCs for TAAs presentation. The results showed that M1 macrophages repolarized from TAMs by Fe@PDA-PEG could capture, process and present TAAs released by PTT through the major histocompatibility complex class II (MHC II) pathway, recruiting T-helper cells and effector T cells in tumor site, which leads to the controlled tumor growth and limited malignant metastasis.

Solubility and bioavailability enhancement study of lopinavir solid dispersion matrixed with a polymeric surfactant - Soluplus.

As a biopharmaceutical classification system Class IV drug, lopinavir (LPV) shows relatively poor water solubility and permeation in vivo. In the study, we developed novel solid dispersions (SD) of LPV to improve its bioavailability and to describe their overall behaviors. By employing solvent evaporation for a preliminary formulation screening, the SDs of LPV-polymer-sorbitan monolaurate (SBM, as the wetting agent) at 1:4:0.4 (w/w) dramatically enhanced the LPV dissolution in a non-sink medium, and then hot-melt extrusion (HME) was applied to improve the dissolution further. A hydrophilic polymer - Kollidon VA 64 (VA64) and a polymeric surfactant Soluplus were employed as matrix respectively in the optimized formulations. The dissolution profiles of extrudates were significantly higher than those of SDs prepared with solvent-evaporation method. It was attributed to the stronger intermolecular interactions between LPV and the polymers in the HME process, which was also supported by the stability analysis after 6 months storage under 25 °C/60% RH. The differential scanning calorimetry, fourier transform infrared spectroscopy and equilibrium studies showed VA64 only created hydrogen bonding (H-bond) with LPV, but Soluplus generated both H-bond and micelle thanks to its amphiphilic structure. In addition, the bioavailability of LPV in Soluplus matrixed extrudate was 1.70-fold of VA64 matrixed extrudate and 3.70-fold of LPV crystal. In situ permeability and Caco-2 cell transport studies revealed that Soluplus significantly enhanced the permeability of LPV through rat intestine and Caco-2 cell monolayers by P-glycoprotein (P-gp) inhibition. Herein, Soluplus matrixed extrudate improved the LPV bioavailability through three mechanisms: H-bond with LPV, micelle formation in water and P-gp inhibition in vivo. These unique advantages of Soluplus suggested it is a promising carrier for poorly water soluble drugs, especially the substrates of P-gp.

Transforming Weakness into Strength: Photothermal-Therapy-Induced Inflammation Enhanced Cytopharmaceutical Chemotherapy as a Combination Anticancer Treatment.

A new synergistic treatment that combines photothermal therapy (PTT) and inflammation-mediated active targeting (IMAT) chemotherapy based on cytopharmaceuticals is developed. During PTT, the photothermal tumor ablation is accompanied by an inflammatory effect and upregulation of inflammatory factors at the tumor site, which may accelerate tumor regeneration. Moreover, PTT-induced inflammation can also recruit neutrophils (NEs) to the tumor site. To convert the disadvantages of PTT-induced inflammation into strengths, NEs are investigated as cytopharmaceuticals for IMAT chemotherapy to further inhibit the tumor recurrence after PTT due to the chemotaxis of NEs to the inflammatory sites. In this study, PEGylated gold nanorods (PEG-GNRs) are explored as the photothermal agent and paclitaxel-loaded cytopharmaceuticals of NEs as the IMAT chemotherapeutic agent. PTT is conducted at 72 h postinjection of PEG-GNRs, followed by cytopharmaceuticals for IMAT chemotherapy. It is demonstrated that the cytopharmaceuticals effectively accumulate in the tumor sites after PTT, which leads to a significant enhancement of antitumor efficacy and a reduction in systemic toxicity. These studies suggest that PTT-induced inflammation further enhances the chemotherapy of cytopharmaceuticals, and the combination of PTT and IMAT chemotherapy may be a promising synergistic strategy for targeted cancer therapy.

Co-delivery of paclitaxel and anti-survivin siRNA via redox-sensitive oligopeptide liposomes for the synergistic treatment of breast cancer and metastasis.

The overexpression of survivin in breast cancer cells is an important factor of paclitaxel (PTX) resistance in breast cancer. To overcome PTX resistance and improve the antitumor effect of PTX, we developed a novel liposome-based nanosystem (PTX/siRNA/SS-L), composed of a redox-sensitive cationic oligopeptide lipid (LHSSG2C14) with a proton sponge effect, natural soybean phosphatidylcholine (SPC), and cholesterol for co-delivery of PTX and anti-survivin siRNA, which could specifically downregulate survivin overexpression. PTX/siRNA/SS-L exhibited high encapsulation efficiency and rapid redox-responsive release of both PTX and siRNA. Moreover, in vitro studies on the 4T1 breast cancer cells revealed that PTX/siRNA/SS-L offered significant advantages over other experimental groups, such as higher cellular uptake, successful endolysosomal escape, reduced survivin expression, the lowest cell viability and wound healing rate, as well as the highest apoptosis rate. In particular, in vivo evaluation of 4T1 tumor-bearing mice showed that PTX/siRNA/SS-L had lower toxicity and induced a synergistic inhibitory effect on tumor growth and pulmonary metastasis. Collectively, the collaboration of anti-survivin siRNA and PTX via redox-sensitive oligopeptide liposomes provides a promising strategy for the treatment of breast cancer and metastasis.

Oral absorption enhancement of salmon calcitonin by using both N-trimethyl chitosan chloride and oligoarginines-modified liposomes as the carriers.

In this study both N-trimethyl chitosan chloride (TMC) and oligoarginine (Arg8) were utilized to modify liposomes as the multifunctional carriers (TMC-Arg8-Lips) for enhancing the oral absorption of salmon calcitonin. Two permeation enhancers with positive charges were sequentially adsorbed on the liposomal surface with negative charges by electrostatic interaction. Instead of salmon calcitonin, fluorescein isothiocyanate dextran (FD4) was loaded in TMC-Arg8-Lips for Caco-2 cell permeation test in vitro and penetration examination in rat intestinal tract in vivo. The results showed that the apparent permeability coefficient (Papp) of TMC-Arg8-Lips containing FD4 were 7.0-, 4.4-, 1.8- and 1.4-folds higher than FD4 solution, FD4-TMC solution, non-modified liposomes (Non-Lips) and TMC modified liposomes (TMC-Lips), respectively. A strong fluorescence was observed by confocal laser scanning microscope (CLSM) at rat intestinal wall isolated in different times after the FD4 loaded carriers were intragastrically administrated. Furthermore, the images revealed that TMC-Arg8-Lips could penetrate deeply inside the mucosal membrane. The pharmacodynamic study indicated that TMC-Arg8-Lips containing calcitonin were more efficient in enhancing the absorption and prolonging the reduction of blood calcemia in rats. The area above the plasma calcium concentration-time curve (AAC) of TMC-Arg8-Lips containing calcitonin was increased by more than 16.6- and 1.6-fold when compared to Non-Lips and TMC-Lips, respectively.

ROS-triggered and regenerating anticancer nanosystem: an effective strategy to subdue tumor's multidrug resistance.

Drug delivery strategies utilizing tumor microenvironment are recognized as a critical doorway to overcome multidrug resistance (MDR). However, the variability of tumor microenvironment at different disease stages would definitely minimize stimuli generation and eventually the therapeutic effects of these stimuli sensitive systems. Herein, we report a unique reactive oxygen species (ROS) triggered nanosystem that can replenish the ROS upon disassembly to maintain its high level. This was accomplished by a new amphiphilic polymer (TBH) composed of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS), hyaluronic acid (HA) and arylboronic ester. As a linker of TPGS to HA, arylboronic ester could efficiently degrade in response to ROS resulting in dismantling of nanosystem followed by rapid release of TPGS. Owing to ROS inducing activity of TPGS with mitochondrial respiratory complex II, ROS regeneration was observed for TBH nanosystem both in MCF-7/ADR cells and tumor tissues xenografted with MCF-7/ADR cells. Furthermore, doxorubicin-loaded TBH nanosystem (DOX-TBH) revealed higher drug cytotoxicity due to enhanced retention effect on account of ROS triggered DOX release and P-gp inhibitory mechanism of TPGS. Moreover, HA significantly improved tumor targeting capability of DOX-TBH, while ROS based triggering and regenerating mechanism lead to marked inhibition of the tumor growth in the xenograft MCF-7/ADR tumor-bearing nude mice.

Preparation and optimization of transferrin-modified-artemether lipid nanospheres based on the orthogonal design of emulsion formulation and physically electrostatic adsorption.

Artemether has been used for a long time in the treatment of malaria as safe and non expensive drug. It possesses potent anticancer effects in cancer cell lines. Our aim was to develop transferrin-modified-artemether lipid nanospheres as targeted anticancer drug delivery system. In this study, artemether intravenous delivery system was prepared by emulsifying method as lipid nanospheres containing mixture of soya oil and crodamol as the core and soya lecithin and Tween 80 as coating layer. According to the physicochemical characterization, the process and formulation variables were optimized by orthogonal design and ANOVA analysis. Based on the electrostatic interaction, transferrin (TR) was physically adsorbed onto the coating layer; the effect of medium pH and the charge of the nanocarriers on the adsorption were investigated. The in vitro characterizations were carried out including, the zeta potential, AFM, TEM, FTIR, (1)H NMR and gel filtration. ART-LNSs with high entrapment efficiency, small size of about 50 nm and monodispersity were formulated. Optimized and stable TR-LNSs, a lipoprotein like structure and size, were produced. We showed a method by which TR can be bound to lipid nanospheres without the need for chemical modification as a base for the development of safe, effective and non expensive anticancer drug delivery system.

Octreotide-mediated tumor cell uptake and intracellular pH-responsive drug delivery of the self-assembly supramolecular nanocarrier.

In this study, DOX-loaded supramolecular nanocarrier (DLSC) was assembled by using two new amphiphilic polymers, octreotide-polyethylene glycol monostearate (OPMS) and N-octyl-N-succinyl O-carboxymethyl chitosan (OSCC). The characteristics of the DLSC were investigated. The results indicated that the significant pH-triggered release in vitro. The cellular uptake of DLSC was much higher than that of DOX-loaded OSCC micelles (DLOM) in the SMMC-7721 (somatostatin receptor (SSTR) over-expressed cell) cells, which suggested the SSTR-mediated properties. A considerable amount of drug entered the nucleus due to the pH-triggered deformation of the supramolecular structure and rapid release of drug in acidic endosomes of tumor cells. The killing efficacy was much higher than that of DLOM in the SMMC-7721. In S180 sarcoma-bearing KM mice, the biodistribution and therapeutic activity were studied. DLSC showed extended circulation time in plasma, decreasing drug concentrations in the heart and accumulating drug concentrations in the pancreas and tumor. In addition, minimized weight changes and cardiac toxicity, high suppression ratio of tumor growth and longer survival time were observed after intravenous injection of DLSC. The studies suggested that the supramolecular nanocarrier constructed of different designated polymers with multiple functions would be one of the most effective approaches for active targeting drug delivery.