Controlled Liposome Delivery from Chitosan-Based Thermosensitive Hydrogel for Regenerative Medicine

This work describes the development of an injectable nanocomposite system based on a chitosan thermosensitive hydrogel combined with liposomes for regenerative medicine applications. Liposomes with good physicochemical properties are prepared and embedded within the chitosan network. The resulting nanocomposite hydrogel is able to provide a controlled release of the content from liposomes, which are able to interact with cells and be internalized. The cellular uptake is enhanced by the presence of a chitosan coating, and cells incubated with liposomes embedded within thermosensitive hydrogels displayed a higher cell uptake compared to cells incubated with liposomes alone. Furthermore, the gelation temperature of the system resulted to be equal to 32.6 °C; thus, the system can be easily injected in the target site to form a hydrogel at physiological temperature. Given the peculiar performance of the selected systems, the resulting thermosensitive hydrogels are a versatile platform and display potential applications as controlled delivery systems of liposomes for tissue regeneration.

Simultaneous Exposure of Different Nanoparticles Influences Cell Uptake

Drug delivery using nano-sized carriers holds tremendous potential for curing a range of diseases. The internalisation of nanoparticles by cells, however, remains poorly understood, restricting the possibility for optimising entrance into target cells, avoiding off-target cells and evading clearance. The majority of nanoparticle cell uptake studies have been performed in the presence of only the particle of interest; here, we instead report measurements of uptake when the cells are exposed to two different types of nanoparticles at the same time. We used carboxylated polystyrene nanoparticles of two different sizes as a model system and exposed them to HeLa cells in the presence of a biomolecular corona. Using flow cytometry, we quantify the uptake at both average and individual cell level. Consistent with previous literature, we show that uptake of the larger particles is impeded in the presence of competing smaller particles and, conversely, that uptake of the smaller particles is promoted by competing larger particles. While the mechanism(s) underlying these observations remain(s) undetermined, we are partly able to restrain the likely possibilities. In the future, these effects could conceivably be used to enhance uptake of nano-sized particles used for drug delivery, by administering two different types of particles at the same time.

Injectable and pH-responsive self-assembled peptide hydrogel for promoted tumor cell uptake and enhanced cancer chemotherapy

An injectable, pH-responsive, in situ self-assembled drug-peptide hydrogel (MTX-KKFKFEFEF(DA)) for highly efficient local tumor chemotherapy.

Novel biomarker and drug delivery systems for theranostics – extracellular vesicles

Extracellular vesicles (EVs) are nano- and micro-sized double-layered membrane entities derived from most cell types and released into biological fluids. Biological properties (cell-uptake, biocompatibility), and chemical (composition, structure) or physical (size, density) characteristics make EVs a good candidate for drug delivery systems (DDS). Recent advances in the field of EVs (e.g., scaling-up production, purification) and developments of new imaging methods (total-body positron emission tomography [PET]) revealed benefits of radiolabeled EVs in diagnostic and interventional medicine as a potential DDs in theranostics.

Investigation of the zinc uptake system of the human fungal pathogen Candida parapsilosis

Candida parapsilosis is the second or third most commonly isolated Candida species from blood cultures and is frequently associated with infections in neonatal intensive care units. Candida species have several virulence factors enabling them to adapt to host environmental conditions and cause infections. These factors include adhesion, biofilm formation, and secretion of hydrolytic enzymes, such as acidic proteinases and lipases. Candida species also obtain heavy metal ions from their environment, such as zinc. Zinc is a cofactor of several proteins and a vital element in cellular mechanisms of the fungi. On the one hand, the host niche represents a zinc-limited environment, that indirectly inhibits microbial growth. In order to survive in such an environment, these pathogens have evolved a zinc transport system that allows them to access bound zinc ions during infection. On the other hand, high zinc ion concentration within the host can also be toxic to microbes e.g. in the phagosomes of Mycobacterium tuberculosis infected macrophages. In case of C. albicans, zinc acquisition processes are intensively studied, but we lack information of the zinc uptake, transfer and homeostasis mechanisms in C. parapsilosis. Here, predicted potential zinc transporters in C. parapsilosis using in silico analyses, generated homozygous knock out mutants and performed their phenotypical characterization by exposing them to various types of stressors and zinc limiting conditions. Furthermore, we analyzed their virulence traits by examining kinetics of fungal cell uptake by macrophages, their killing efficiency and also investigated zinc ion levels in the phagolysosome during in vitro infections

Interaction between Flavonoids and Carotenoids on Ameliorating Oxidative Stress and Cellular Uptake in Different Cells

Flavonoids (quercetin, luteolin) and carotenoids (lycopene, lutein) were combined at different molecular ratios in a total concentration of 8 μM to investigate their antioxidant interactions. Cellular uptake of carotenoids, the expression of carotenoid transporters, the ROS scavenging ability, and antioxidant enzymes activities were compared in HUVEC, Caco-2, and L-02 cells. Combinations with flavonoids in the majority showed stronger antioxidant activity. Lycopene combined with quercetin at ratio 1:5 showed stronger ROS scavenging activities, increased 18, 12, and 12 Cellular antioxidant activity (CAA) units in HUVEC, Caco-2, and L-02 cells, respectively, and promoted SOD and CAT activities than individual component. The cell uptake of carotenoids was enhanced by flavonoids in antioxidant synergistic groups, while dampened by flavonoids in antagonistic groups in HUVEC cells. The synergistic group (lycopene:quercetin = 1:5) increased lycopene uptake by 271%, while antagonistic group (lutein:quercetin = 5:1) decreased lutein uptake by 17%. Flavonoids modulated the effects of carotenoids on the expression of active transporters scavenger receptor class B type I (SR-BI) or Niemann-Pick C1-like 1 (NPC1L1). The synergistic group (lycopene:quercetin = 1:5) increased the expression of SR-BI compared to individual lycopene treatment in HUVEC and Caco-2 cells. Thus, a diet rich in both flavonoids and lycopene possesses a great antioxidant activity, especially if a higher amount of flavonoids is included.

Exosomes From Human Urine-Derived Stem Cells Encapsulated Into PLGA Nanoparticles for Therapy in Mice With Particulate Polyethylene-Induced Osteolysis

Background: Periprosthetic osteolysis is the primary reason for arthroplasty failure after total joint replacement because of the generation of wear particles and subsequent bone erosion around the prosthesis, which leads to aseptic loosening. Periprosthetic osteolysis is often treated with revision surgery because of the lack of effective therapeutic agents. As key messengers of intercellular interactions, exosomes can be independently used as therapeutic agents to promote tissue repair and regeneration. In this study, we fabricated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) that carry exosomes derived from human urine stem cells (USC-Exos) and explored their effects on polyethylene-induced osteolysis.Methods: USCs were identified by multipotent differentiation and flow cytometry analyses. USC-Exos were isolated and identified by transmission electron microscopy (TEM), dynamic light scattering (DLS), and western blotting. PLGA microspheres containing USC-Exos were fabricated to synthesize NPs using the mechanical double-emulsion method. The obtained NPs were characterized in terms of stability, toxicity, exosome release, and cell uptake. Then, these NPs were implanted into the murine air pouch model, and their effects on polyethylene-induced osteolysis were evaluated by microcomputed tomography (micro-CT) and histological analyses.Results: The average NP diameter was ~282 ± 0.4 nm, and the zeta potential was −2.02 ± 0.03 mV. After long-term storage at room temperature and 4°C, the NP solution was stable without significant coaggregation. In vitro release profiles indicated sustained release of exosomes for 12 days. In vivo, injection of NPs into the murine air pouch caused less osteolysis than that of USC-Exos, and NPs significantly reduced bone absorption, as indicated by histology and micro-CT scanning.Conclusion: Our findings suggest that USC-Exo-based PLGA NPs can prevent particulate polyethylene-induced osteolysis and bone loss.

Multifunctional Nanoparticles Loaded with Vascular Endothelial Growth Factor Inhibitors and MED1 siRNA to Inhibit Breast Cancer Progression by Targeting Tumor-Associated Macrophages and Breast Cancer Cells

Breast cancer is still threatening many people’ lives, hence novel targeted therapies are urgently required to improve the poor outcome of breast cancer patients. Herein, our study aimed to explore the potential of nanoparticles (NPs)-loaded with VEGF inhibitors and MED1 siRNA for treatment of the disorder. PEG and MTC conjugates were synthesized by ion gelation, and equipped with VEGF inhibitor (siV) and MED1 (siD) siRNA (MT/PC/siV-D NPs). The size and morphology of the NPs were detected by TEM. Agarose gel experiment was performed to detect drug encapsulation rate and NPs stability. Zeta potential was assessed by immunofluorescence assay and cell uptake was detected by fluorescence analysis. After cancer cells were treated with NPs or PBS, cell proliferation and invasion were evaluated with VEGF and MED1 expression was detected by Western blot and RT-qPCR analyses. Animal model was conducted to confirm the role of NPs in tumor growth. Results showed that, the MT/PC/siV-D NPs exhibited great stability, drug encapsulation and internalization ability. The combined NPs caused decreased proliferation and invasion of tumor cells, inducing M2 macrophages to re-polarize to M1 type with declined expression of VEGF and MED1. Moreover, the NPs remarkably alleviated breast tumor progression. The multifunctional NPs equipped with EGF inhibitors and MED1 siRNA can inhibit tumor progression by targeting TAMs and cancer cells during breast cancer.

A novel targeted co-delivery nanosystem for enhanced ovarian cancer treatment via multidrug resistance reversion and mTOR-mediated signaling pathway

Background Multidrug resistance (MDR) is the main challenge of successful chemotherapy for ovarian cancer patients, with 50% to 75% of ovarian cancer patients eventually relapsed due to it. One of the effective strategies for treating MDR and improving therapeutic efficiency of ovarian cancer is to use nanotechnology-based targeted drug delivery systems. In this study, a novel nano targeted co-delivery system modified by hyaluronic acid (HA) was developed by using gold nanorods coated with functionalized mesoporous silica nanoparticles (HA-PTX/let-7a-GNR@MSN) for combined delivery of hydrophobic chemotherapy drug Paclitaxel (PTX) and lethal-7a (let-7a), a microRNA (miR), to overcome MDR in ovarian cancer. Furthermore, we also analyzed the molecular mechanism of this nanotherapeutic system in the treatment of ovarian cancer. Results HA-modified nanocomplexes can specifically bind to the CD44 receptor, which is highly expressed in SKOV3/SKOV3TR cells, achieving effective cell uptake and 150% enhancement of tumor site permeability. The nanosystem realized the stable combination and protective transportation of PTX and miRs. Analysis of drug-resistant SKOV3TR cells and an SKOV3TR xenograft model in BALB/c-nude mice showed significant downregulation of P-glycoprotein in heterogeneous tumor sites, PTX release, and subsequent induction of apoptosis. More importantly, this nanosystem could synergistically inhibit the growth of ovarian tumors. Further studies suggest that mTOR-mediated signaling pathways play an important role in reversing drug resistance and inducing apoptosis. Conclusions To sum up, these data provide a model for overcoming PTX resistance in ovarian cancer. Graphical Abstract