Safe Induction of Acute Inflammation with Enhanced Antitumor Immunity by Hydrogel-Mediated Outer Membrane Vesicle Delivery.

Acute inflammation has the potential for the recruitment of immune cells, inhibiting tumor angiogenesis, metastasis, and drug resistance thereby overcoming the tumor immunosuppressive microenvironment caused by chronic inflammation. Here, an acute inflammation inducer using bacteria outer membrane vesicles (OMVs) loaded in thermal-sensitive hydrogel (named OMVs-gel) for localized and controlled release of OMVs in tumor sites is proposed. OMVs trigger neutrophil recruitment and amplify acute inflammation inside tumor tissues. The hydrogel ensures drastic inflammation is confined within the tumor, addressing biosafety concerns that the direct administration of free OMVs may cause fatal effects. This strategy eradicated solid tumors safely and rapidly. The study further elucidates one of the possible immune mechanisms of OMVs-gel therapy, which involves the assembly of antitumor neutrophils and elastase release for selective tumor killing. Additionally, tumor vascular destruction induced by OMVs-gel results in tumor darkening, allowing for combinational photothermal therapy. The findings suggest that the use of OMVs-gel can safely induce acute inflammation and enhance antitumor immunity, representing a promising strategy to promote acute inflammation application in tumor immunotherapy.

Multiple delivery strategies of nanocarriers for myocardial ischemia-reperfusion injury: current strategies and future prospective.

Acute myocardial infarction, characterized by high morbidity and mortality, has now become a serious health hazard for human beings. Conventional surgical interventions to restore blood flow can rapidly relieve acute myocardial ischemia, but the ensuing myocardial ischemia-reperfusion injury (MI/RI) and subsequent heart failure have become medical challenges that researchers have been trying to overcome. The pathogenesis of MI/RI involves several mechanisms, including overproduction of reactive oxygen species, abnormal mitochondrial function, calcium overload, and other factors that induce cell death and inflammatory responses. These mechanisms have led to the exploration of antioxidant and inflammation-modulating therapies, as well as the development of myocardial protective factors and stem cell therapies. However, the short half-life, low bioavailability, and lack of targeting of these drugs that modulate these pathological mechanisms, combined with liver and spleen sequestration and continuous washout of blood flow from myocardial sites, severely compromise the expected efficacy of clinical drugs. To address these issues, employing conventional nanocarriers and integrating them with contemporary biomimetic nanocarriers, which rely on passive targeting and active targeting through precise modifications, can effectively prolong the duration of therapeutic agents within the body, enhance their bioavailability, and augment their retention at the injured myocardium. Consequently, these approaches significantly enhance therapeutic effectiveness while minimizing toxic side effects. This article reviews current drug delivery systems used for MI/RI, aiming to offer a fresh perspective on treating this disease.

Enhanced protection against hypoxia/reoxygenation-induced apoptosis in H9c2 cells by puerarin-loaded liposomes modified with matrix metalloproteinases-targeting peptide and triphenylphosphonium.

Based on the inhibition of mitochondrial permeability transition pore (mPTP) opening, puerarin (PUE) has a good potential to reduce myocardial ischemia/reperfusion injury (MI/RI). However, the lack of targeting of free PUE makes it difficult to reach the mitochondria. In this paper, we constructed matrix metalloproteinase-targeting peptide (MMP-TP) and triphenylphosphonium (TPP) cation co-modified liposomes loaded with PUE (PUE@T/M-L) for mitochondria-targeted drug delivery. PUE@T/M-L had a favorable particle size of 144.9 ± 0.8 nm, an encapsulation efficiency of 78.9 ± 0.6%, and a sustained-release behavior. The results of cytofluorimetric experiments showed that MMP-TP and TPP double-modified liposomes (T/M-L) enhanced intracellular uptake, escaped lysosomal capture, and promoted drug targeting into mitochondria. In addition, PUE@T/M-L enhanced the viability of hypoxia-reoxygenation (H/R) injured H9c2 cells by inhibiting mPTP opening and reactive oxygen species (ROS) production, reducing Bax expression and increasing Bcl-2 expression. It was inferred that PUE@T/M-L delivered PUE into the mitochondria of H/R injured H9c2 cells, resulting in a significant increase in cellular potency. Based on the ability of MMP-TP to bind the elevated expression of matrix metalloproteinases (MMPs), T/M-L had excellent tropism for Lipopolysaccharide (LPS) -stimulated macrophages and can significantly reduce TNF-α and ROS levels, thus allowing both drug accumulation in ischemic cardiomyocytes and reducing inflammatory stimulation during MI/RI. Fluorescence imaging results of the targeting effect using a DiR probe also indicated that DiR@T/M-L could accumulate and retain in the ischemic myocardium. Taken together, these results demonstrated the promising application of PUE@T/M-L for mitochondria-targeted drug delivery to achieve maximum therapeutic efficacy of PUE.

Bacterial outer membrane vesicles-based therapeutic platform eradicates triple-negative breast tumor by combinational photodynamic/chemo-/immunotherapy.

Bacterial outer membrane vesicles (OMVs) are potent immuno-stimulating agents and have the potentials to be bioengineered as platforms for antitumor nanomedicine. In this study, OMVs are demonstrated as promising antitumor therapeutics. OMVs can lead to beneficial M2-to-M1 polarization of macrophages and induce pyroptosis to enhance antitumor immunity, but the therapeutic window of OMVs is narrow for its toxicity. We propose a bioengineering strategy to enhance the tumor-targeting ability of OMVs by macrophage-mediated delivery and improve the antitumor efficacy by co-loading of photosensitizer chlorin e6 (Ce6) and chemotherapeutic drug doxorubicin (DOX) into OMVs as a therapeutic platform. We demonstrate that systemic injection of the DOX/Ce6-OMVs@M therapeutic platform, providing combinational photodynamic/chemo-/immunotherapy, eradicates triple-negative breast tumors in mice without side effects. Importantly, this strategy also effectively prevents tumor metastasis to the lung. This OMVs-based strategy with bioengineering may serve as a powerful therapeutic platform for a synergic antitumor therapy.

Multifunctional exosome-mimetics for targeted anti-glioblastoma therapy by manipulating protein corona.

Targeted drug delivery to the glioblastoma (GBM) overcoming blood-brain barrier (BBB) has been challenging. Exosomes are promising vehicles for brain tumor drug delivery, but the production and purification hinder its application for nanomedicine. Besides, the formation of protein corona (PC) may affect the behaviour of nanocarriers. Here, multifunctional exosomes-mimetics (EM) are developed and decorated with angiopep-2 (Ang) for enhancing GBM drug delivery by manipulating PC. Docetaxel (DTX)-loaded EM with Ang modification (DTX@Ang-EM) show less absorption of serum proteins and phagocytosis by macrophages. Ang-EM show enhanced BBB penetration ability and targeting ability to the GBM. Ang-EM-mediated delivery increase the concentration of DTX in the tumor area. The multifunctional DTX@Ang-EM exhibits significant inhibition effects on orthotopic GBM growth with reduced side effects of the chemotherapeutic. Findings from this study indicate that the developed DTX@Ang-EM provide a new strategy for targeted brain drug delivery and GBM therapy.

Artificial exosomes for translational nanomedicine.

Exosomes are lipid bilayer membrane vesicles and are emerging as competent nanocarriers for drug delivery. The clinical translation of exosomes faces many challenges such as massive production, standard isolation, drug loading, stability and quality control. In recent years, artificial exosomes are emerging based on nanobiotechnology to overcome the limitations of natural exosomes. Major types of artificial exosomes include 'nanovesicles (NVs)', 'exosome-mimetic (EM)' and 'hybrid exosomes (HEs)', which are obtained by top-down, bottom-up and biohybrid strategies, respectively. Artificial exosomes are powerful alternatives to natural exosomes for drug delivery. Here, we outline recent advances in artificial exosomes through nanobiotechnology and discuss their strengths, limitations and future perspectives. The development of artificial exosomes holds great values for translational nanomedicine.

Exosomes and biomimetic nanovesicles-mediated anti-glioblastoma therapy: A head-to-head comparison.

Exosomes (Exos) are promising vehicles for brain drug delivery due to nanosize and the ability to breach the blood-brain barrier (BBB). But the low yield of natural exosomes limits its application for nanomedicine. The generation of bioinspired nanovesicles (BNVs) that mimicking Exos is attractive, but there is a lack of comparative evaluation of Exos and BNVs. Here, we perform the first head-to-head comparison study of Exos and BNVs for brain tumor drug delivery. We show that BNVs derived from brain-derived endothelial cells are competent alternative nanocarrier to natural exosomes. The drug-loading capacity of Exos and BNVs are similar, but the yield of BNVs is substantially higher (500-fold) than Exos. Doxorubicin (DOX)-loaded BNVs (BNV/DOX) and DOX-loaded Exos (Exo/DOX) showed similar pharmacokinetic profiles and prolonged circulation od DOX. Despite inconsistent mechanisms, BNV/DOX can across the BBB, and exhibit suppression effects similar to Exo/DOX on the progress of glioblastoma (GBM) in zebrafish and in vivo subcutaneous and orthotopic xenografts mice models, with minimal systemic toxicity. Findings from this head-to-head comparison study indicate that autologous BNVs is a effective alternative of Exos for brain tumor nanomedicine.

Biomimetic Liposome with Surface-Bound Elastase for Enhanced Tumor Penetration and Chemo-Immumotherapy.

Dense extracellular matrix (ECM) in the tumor stroma has been a challenge for drug penetration and cytotoxic T lymphocyte (CTL) infiltration. Neutrophil elastase (NE), in surface-bound form, can destruct ECM rapidly, may be used for remodeling tumor ECM, and overcoming tumor stromal barrier. Focusing on elastosis in triple-negative breast tumor, biomimetic liposomes with chimeric cell membrane proteins (LMP) are developed and for the first time, it is demonstrated that LMP with surface-bound elastase (NE-LMP) can target and degrade ECM effectively in tumor stroma, with minimal toxicity to normal tissues. The pretreatment of NE-LMP increases the accumulation of chemotherapeutics at the tumor site and enhances antitumor effects. Also, NE-LMP facilitates CTL infiltration in tumors and exhibits enhanced chemo-immunotherapy in combination of PD-1 immune checkpoint blockade treatment in orthotopic 4T1 tumor-bearing mice, with significantly prolonged survival. Moreover, the remodeling of the tumor ECM by NE-LMP shows inhibiting effects on metastasis in the lung. Findings from this study suggest that NE-LMP holds promise for enhancing deep penetration of drug and infiltration of CTL in desmoplastic tumor by effective degrading ECM in the tumor stroma.

Comparative evaluation of methods for isolating small extracellular vesicles derived from pancreatic cancer cells.

BACKGROUND: Small extracellular vesicles (sEVs) are nanosized vesicles involved in cell-to-cell communication. sEVs have been widely studied for clinical applications such as early detection of diseases and as therapeutics. Various methods for sEVs isolation are been using, but different methods may result in different qualities of sEVs and impact downstream analysis and applications. Here, we compared current isolation methods and performed a comparative analysis of sEVs from supernatant of cultured pancreatic cancer cells. METHODS: Ultracentrifugation, ultrafiltration and co-precipitation as concentration methods were firstly evaluated for yield, size, morphology and protein level of pellets. Then, isolate sEVs obtained by four different purification methods: size exclusion chromatography, density gradient ultracentrifugation, ultracentrifugation, and immunoaffinity capturing, were analysed and compared. RESULTS: For the concentration process, ultracentrifugation method obtained high quality and high concentration of pellets. For the purification process, immunoaffinity capturing method obtained the purest sEVs with less contaminants, while density gradient ultracentrifugation-based method obtained sEVs with the smallest size. Proteomic analysis revealed distinct protein contents of purified sEVs from different methods. CONCLUSIONS: For isolating sEVs derived from supernatant of cultured pancreatic cancer cell line, ultracentrifugation-based method is recommended for concentration of sEVs, density gradient ultracentrifugation-based method may be applied for obtaining purified sEVs with controlled size, immunoaffinity capturing may be suitable for studies requiring sEVs with high purity but may loss subtypes of sEVs without specific protein marker.

Preservation of small extracellular vesicles for functional analysis and therapeutic applications: a comparative evaluation of storage conditions.

Extracellular vesicles (EVs) are nanovesicles involved in multiple biological functions. Small EVs (sEVs) are emerging as therapeutics and drug delivery systems for their contents, natural carrier properties, and nanoscale size. Despite various clinical application potentials, little is known about the effects of storage conditions on sEVs for functional analysis and therapeutic use. In this study, we evaluated the stability of sEVs stored at 4 °C, -20 °C, and -80 °C up to 28 days and compared them to fresh sEVs. Also, the effect of freeze-thawing circles on the quantity of sEVs was assessed. We found that different storage temperatures, along with shelf life, impact the stability of sEVs when compared to freshly isolated sEVs. Storage changes the size distribution, decreases quantity and contents, and impacts cellular uptake and biodistribution of sEVs. For functional studies, isolated sEVs are suggested to be analyzed freshly or stored at 4 °C or -20 °C for short-term preservation depending on study design; but -80 °C condition would be more preferable for long-term preservation of sEVs for therapeutic application.

3,5,4'-Trimethoxy-trans-stilbene loaded microemulsion for cutaneous melanoma therapy by transdermal drug delivery.

For therapy of skin cancer, transdermal administration has been a potential way to enhance chemotherapy. However, the drug delivery efficacy remained unsatisfactory because of the physiological barriers from the skin to the tumor, which hindered the effect of 3,5,4'-trimethoxy-trans-stilbene (BTM), a drug that has toxicity to cancer. Herein, we prepared an oil-in-water (O/W) microemulsion to load BTM (BTM-ME) for transdermal therapy of melanoma. BTM-ME was characterized by size, zeta potential, and polymer disperse index (PDI). B16F10 melanoma cell line was used for cell experiments and animal models. And cell uptake, viability assay, and flow cytometry were to test the cell internalization and the ability of BTM-ME to induce cancer cell apoptosis. Skin penetration testing was to detect its penetration efficiency to the skin. And tumor-bearing mice were used to prove the improvement of anti-cancer efficacy of BTM-ME with the combination of Taxol. BTM was successfully loaded in O/W microemulsion, with a drug loading capacity of 24.82 mg/mL. BTM-ME can penetrate the skin and increase the retention of BTM in the epidermis. And the combination of Taxol and BTM-ME effectively suppressed tumor growth and has lower toxicity to normal organs. BTM-ME provides adjuvant therapy to cutaneous melanoma and the combination of Taxol and BTM-ME has the clinical potential for skin cancer therapy. Graphical abstract.

Emerging strategies for labeling and tracking of extracellular vesicles.

Extracellular vesicles (EVs) are cell-derived lipid bilayer-enclosed nanovesicles. EVs are emerging as keys for identifying molecular mechanisms by mediating intercellular communication. EVs allow the exchange of various components with neighboring and distant cells through the extracellular environment, thereby involving in various biological processes in both physiological and pathological conditions such as wound healing, immune response, and tumorigenesis. EVs are also growing rapidly as cargo carrier for their natural delivery properties. Development of bioinspired delivery nanoplatforms based on exosomes-like mimetics also showed potentials to overcome limitations of synthetic nanoparticles. EVs offer a window to multicomponent diagnosis and a tool for design therapeutics. However, for successful clinical translation of EVs, the understanding of in vivo behavior is essential. Advancements in molecular imaging enabled high-resolution in vivo tracking of EVs, providing valuable information regarding trafficking, biodistribution, cellular uptake and molecular mechanism of EVs. Recent studies have explored various methods for visualizing EVs, each imaging technique has certain strengths and limitations. Highly specific, sensitive and biocompatible labeling and tracking strategies still in demand in EV visualization. In this review, we summarized methods for labeling and tracking of EVs and discussed benefits and drawbacks for each method. Future novel imaging modalities and combined strategies will provide avenues for understanding EV behavior and accelerate their clinical translation.

Extracellular vesicles derived from different sources of mesenchymal stem cells: therapeutic effects and translational potential.

Mesenchymal stem cells (MSCs) were known to have excellent properties in cell therapy. However, the risk of immune rejection associated with cell transplant therapy hampers its use. Extracellular vesicles secreted by MSCs derived from different sources that contain therapeutic molecules such as RNA and proteins, which is a novel strategy for cell-free therapy. Recently, researches show EVs from MSCs (MSC-EVs) of different sources have special functions and effects on different diseases. Here, we collected these researches and compared them to each other. In addition, their potential and possible application in clinical treatment are described.

The Brief Analysis of Peptide-combined Nanoparticle: Nanomedicine's Unique Value.

Therapeutic peptides (TPs) are biological macromolecules which can act as neurotransmitters, hormones, ion channel ligands and growth factors. Undoubtedly, TPs are crucial in modern medicine. But low bio-stability and some special adverse reactions reduce their places to the application. With the development of nanotechnology, nanoparticles (NPs) in pharmaceutical science gained much attention. They can encapsulate the TPs into their membrane or shell. Therefore, they can protect the TPs against degradation and then increase the bioavailability, which was thought to be the biggest advantage of them. Additionally, targeting was also studied to improve the effect of TPs. However, there were some drawbacks of nano TPs like low loading efficiency and difficulty to manufacture. Nowadays, lots of studies focused on improving effect of TPs by preparing nanoparticles. In this review, we presented a brief analysis of peptide-combined nanoparticles. Their advantages and disadvantages were listed in terms of mechanism. And several examples of applications were summarized.

Gemcitabine loaded autologous exosomes for effective and safe chemotherapy of pancreatic cancer.

Pancreatic cancer remains one of the most highly lethal diseases with very poor prognosis. Gemcitabine (GEM) is the first-line chemotherapeutic drug for pancreatic cancer treatment but is associated with significant side effects when administered systemically. Exosomes have emerged as attractive candidates for drug delivery for their high delivery efficiency and biocompatibility. Here, GEM was loaded into autologous exosomes to formulate ExoGEM for targeted chemotherapy of pancreatic cancer. Autologous exosomes facilitate cellular uptake of GEM and contributed to significantly increased cytotoxic effect of GEM, while heterologous cellular uptake showed less efficiency. Autologous exosomes showed targeting ability to pancreatic cancer in biodistribution study, and GEM concentration in tumor site was increased via ExoGEM delivery. ExoGEM treatment, in tumor-bearing mice, significantly suppressed tumor growth, with prolonged survival in a dose-response manner, but caused minimal damage to normal tissues. More importantly, tumors in several mice treated with ExoGEM were disappeared without recurrence. Autologous exosomes are safe and effective vehicles for targeted delivery of GEM against pancreatic cancer. This delivery strategy may have implications for personalized chemotherapy of pancreatic cancer. STATEMENT OF SIGNIFICANCE: Exosomes are efficient delivery vehicles in intracellular communication. Moreover, potential tropism of autologous exosomes to the tumor microenvironment make them competitive delivery vehicles. The use of cancer-derived exosomes for drug delivery and superior targeting efficacy and enhanced anticancer efficacy of therapeutics have been evidenced. Gemcitabine is a mainstay for pancreatic treatment. However, poor cellular uptake and low targeting effects of gemcitabine often lead to severe systemic toxicity. Therefore, to overcome this limitation, we herein loaded gemcitabine into autologous pancreatic cancer-derived exosomes for the targeted chemotherapy of pancreatic cancer.

Micelles Loaded With Puerarin And Modified With Triphenylphosphonium Cation Possess Mitochondrial Targeting And Demonstrate Enhanced Protective Effect Against Isoprenaline-Induced H9c2 Cells Apoptosis.

BACKGROUND: The protective role of puerarin (PUE) against myocardial infarction is closely related to its regulation on mitochondria. However, free PUE can hardly reach the mitochondria of ischemic cardiomyocytes due to the lack of mitochondrial targeting of PUE. Here PUE was loaded into mitochondria-targeted micelles (PUE@TPP/PEG-PE) for precisely delivering PUE into mitochondria with the aim of enhancing the anti-apoptosis effect. METHODS: The mitochondriotropic polymer TPP-PEG-PE was synthesized for the preparation of PUE@TPP/PEG-PE micelles modified with triphenylphosphonium (TPP) cation. The physicochemical properties and anti-apoptosis effect of PUE@TPP/PEG-PE micelles were investigated. The coumarin 6 (C6)-labeled TPP/PEG-PE (C6@TPP/PEG-PE) micelles were used to observe the enhanced cellular uptake, mitochondrial targeting and lysosomes escape. Moreover, in vivo and ex vivo biodistribution of lipophilic near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR)-labeled PUE@TPP/PEG-PE (DiR@TPP/PEG-PE) micelles were detected through fluorescence imaging. RESULTS: The successful synthesis of TPP-PEG-PE conjugate was confirmed. PUE@TPP/PEG-PE micelles had a particle size of 17.1 nm, a zeta potential of -6.2 mV, and a sustained-release behavior. The in vitro results showed that the intracellular uptake of C6@TPP/PEG-PE micelles was significantly enhanced in H9c2 cells. C6@TPP/PEG-PE micelles could deliver C6 to mitochondria and reduce the capture of lysosomes. In addition, compared with the PUE@PEG-PE micelles and free PUE, the PUE@TPP/PEG-PE micelles exerted an enhanced protective effect against isoprenaline-induced H9c2 cell apoptosis, as evident by the decreased percentage of apoptotic cells, Caspase-3 activity, ROS level, Bax expression, and increased Bcl-2 expression. The in vivo detecting results of the targeting effect using DiR probe also indicated that TPP/PEG-PE micelles could accumulate and retain in the ischemic myocardium. CONCLUSION: The results of this study demonstrate the promising potential of applying PUE@TPP/PEG-PE micelles in mitochondria-targeted drug delivery to achieve maximum therapeutic effects of PUE.

3,5,4'-trimethoxy-trans-stilbene loaded PEG-PE micelles for the treatment of colon cancer.

BACKGROUND: 3,5,4'-trimethoxy-trans-stilbene (BTM) is a methylated derivative of resveratrol. To improve the pharmaceutical properties of BTM, BTM loaded PEG-PE micelles (BTM@PEG-PE) were fabricated and its anti-cancer efficacy against colon cancer was evaluated. METHODS: BTM@PEG-PE micelles were prepared by the solvent evaporation method and were characterized by nuclear magnetic resonance (NMR), size, zeta potential, polymer disperse index (PDI) and transmission electron microscopy (TEM). Cellular uptake, cell viability assay, caspase-3 activity assay and flow cytometry were performed to evaluate the cell internalization and anti-cancer efficacy of BTM@PEG-PE micelles in vitro. Pharmacokinetic profiles of BTM and BTM@PEG-PE micelles were compared and in vivo anti-cancer therapeutic efficacy and safety of BTM@PEG-PE micelles on CT26 xenograft mice were evaluated. RESULTS: BTM was successfully embedded in the core of PEG-PE micelles, with a drug loading capacity of 5.62±0.80%. PEG-PE micelles facilitated BTM entering to the CT26 cells and BTM@PEG-PE micelles exerted enhanced anti-cancer efficacy against CT26 cells. BTM@PEG-PE micelles showed prolonged half-life and increased bioavailability. More importantly, BTM@PEG-PE micelles treatment suppressed tumor growth in tumor-bearing mice and prolonged survival with minimal damage to normal tissues. CONCLUSION: Altogether, the BTM@PEG-PE micelles might be a promising strategy to enhance the pharmacokinetic and pharmacodynamic potentials of BTM for colon cancer therapy.

[In vitro evaluation, cellular uptake and anti-acute myocardial ischemia effect of puerarin PEG-PLGA micelles].

PUE@PEG-PLGA micelles has excellent characteristics such as small particle size, high drug loading and slow drug release. The results of TEM electron microscopy showed that PUE@PEG-PLGA micelles had obvious core-shell structure. The critical micelle concentration(CMC) of PEG-PLGA micelles determined by pyrene assay was about 4.8 mg·L~(-1). Laser confocal experiments showed that PEG-PLGA micelles can enhance the cellular uptake of coumarin-6 and aggregate around the mitochondria; quantitative results of extracellular drug residues also indirectly confirmed that PEG-PLGA micelles can promote cellular uptake of the drug. Acute ischemic myocardial model rats were prepared by coronary artery ligation, and then the model rats were randomly divided into six groups: Sham operation group, model group, puerarin(PUE) group, as well as low-, mid-, and high-dose PUE@PEG-PLGA micelles groups. Drugs were given by iv administration 5 min after the ligation. The ST segment changes in the electrocardiogram were monitored; serum creatine kinase(CK), lactate dehydrogenase(LDH), aspartate aminotransferase(AST), and malondialdehyde(MDA) levels were detected and myocardial infarct size was also measured. Both PUE and PUE@PEG-PLGA micelles can reduce the elevated ST segment, reduce serum CK, LDH, AST and MDA levels, and reduce myocardial infarct size. The efficacy of PUE@PEG-PLGA medium and high dose groups was significantly better than that in the PUE group, and the efficacy in PUE@PEG-PLGA low dose group was basically equivalent to that in the PUE group. PUE@PEG-PLGA micelles can greatly improve the cardiomyocytes uptake of PUE, enhance the anti-acute myocardial ischemia effect of drugs, and reduce its dosage.

Oral microemulsion based delivery system for reducing reproductive and kidney toxicity of Tripterygium glycosides.

Aim: To reduce the toxic effects and achieve efficiency of Tripterygium glycosides, an oral microemulsion was designed. Method: After estimating its stability and characterisation, an animal experiment was held to evaluate its toxicity in vivo, using male and female Sprague Dawley rats. Result: The maximum loading amount of microemulsion to Tripterygium glycosides was 18.87 mg/ml. And comparing to control, the Tripterygium glycoside microemulsion can maintain a normal level of the number of sperms, the weight of testicle, testosterone (∼2.5 ng/mL) and BUN (∼5 mmol/L) to male rats. For female rats, it can prevent the ovary to be atrophy and keep FSH to be stable (>2100 ng/L). The weaker injury induced by drug-loaded microemulsion to rats also could be observed in histological sections to kidney and reproductive organs. Conclusions: Although the blank microemulsion had slight toxicity, it mitigated the toxicity of Tripterygium glycosides to kidney and reproductive system.

Phospholipid complex based nanoemulsion system for oral insulin delivery: preparation, in vitro, and in vivo evaluations.

Purpose: The aim of this research was to develop a phospholipid complex based nanoemulsion system for oral insulin delivery. Methods: Insulin-phospholipid complex (IPC) was firstly prepared by an anhydrous co-solvent lyophilization method, and then encapsulated into the oil phase of nanoemulsion to obtain the IPC-based nanoemulsion (IPC-NE). Both water-in-oil (W/O) IPC-NE and oil-in-water (O/W) IPC-NE were formulated and evaluated for comparison. Results: The obtained W/O IPC-NE and O/W IPC-NE were both spherical in shape with a mean particle size of 18.6±0.79 nm and 27.3±1.25 nm, respectively. While both IPC-NEs exhibited enhanced Caco-2 cell monolayers permeability than IPC and insulin solution, W/O IPC-NE showed relatively greater protective effects against enzymatic degradation than O/W IPC-NE. Moreover, oral administration of W/O IPC-NE exhibited significant hypoglycemic effects, with 12.4-fold and 1.5-fold higher oral bioavailability compared with insulin solution and O/W IPC-NE, respectively. Conclusion: IPC-NEs, especially the W/O IPC-NE showed promising efficiency in vitro and in vivo, thus could be a potential strategy for oral insulin delivery.