E2-Loaded Microcapsules and Bone Marrow-Derived Mesenchymal Stem Cells with Injectable Scaffolds for Endometrial Regeneration Application.

Bone marrow-derived mesenchymal stem cells (BMSCs) have been recognized as new candidates for the treatment of serious endometrial injuries. However, owing to the local microenvironment of damaged endometrium, transplantation of BMSCs yielded disappointing results. In this study, Pectin-Pluronic® F-127 hydrogel as scaffolds were fabricated to provide three-dimensional architecture for the attachment, growth, and migration of BMSCs. E2 was encapsulated into the W/O/W microspheres to construct pectin-based E2-loaded microcapsules (E2 MPs), which has the potential to serve as a long-term reliable source of E2 for endometrial regeneration. Then, the BMSCs/E2 MPs/scaffolds system was injected into the uterine cavity of mouse endometrial injury model for treatment. At 4 weeks after transplantation, the system increased proliferative abilities of uterine endometrial cells, facilitated microvasculature regeneration, and restored the ability of endometrium to receive an embryo, suggesting that the BMSCs/E2 MPs/scaffolds system is a promising treatment option for endometrial regeneration. Furthermore, the mechanism of E2 in promoting the repair of endometrial injury was also investigated. Exosomes are critical paracrine mediators that act as biochemical cues to direct stem cell differentiation. In this study, it was found that the expression of endometrial epithelial cell (EEC) markers was upregulated in BMSCs treated by exosomes secreted from endometrial stromal cells (ESCs-Exos). Exosomes derived from E2-stimulated ESCs further promoted the expression level of EECs markers in BMSCs, suggesting exosomes released from ESCs by E2 stimulation could enhance the differentiation efficiency of BMSCs. Therefore, exosomes derived from ESCs play paracrine roles in endometrial regeneration stimulated by E2 and provide optimal estrogenic response.

One-pot synthesis and enzyme-responsiveness of amphiphilic doxorubicin prodrug nanomicelles for cancer therapeutics.

In this study, we report a one-pot synthesis and enzyme-responsiveness of polyethylene glycol (PEG) and glutamic acid (Glu)-based amphiphilic doxorubicin (DOX) prodrug nanomicelles for cancer therapeutics. The nanomicelles were accomplished by esterification and amidation reactions. The nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) data confirmed the structure of nanomicelles. The DOX-loaded nanomicelles showed a DLS-measured average size of 107 nm and excellent stability in phosphate-buffered saline (PBS) for 7 days. The drug loading and cumulative release rates were measured by ultraviolet-visible (UV-vis) spectrophotometry at 481 nm. The cumulative release rate could reach 100% in an enzyme-rich environment. Further, the therapeutic efficiency of nanomicelles to cancer cells was determined by cell viability and cellular uptake and distribution using HeLa cells. The cell viability study showed that the DOX-loaded nanomicelles could effectively inhibit the HeLa cell proliferation. The cellular uptake study confirmed that the nanomicelles could be effectively ingested by HeLa cells and distributed into cell nuclei. Based on the collective experimental data, this study demonstrated that the synthesized nanomicellar prodrug of DOX is a potential candidate for cancer therapeutics.

Green Synthesis of Gold Nanoparticles Using Upland Cress and Their Biochemical Characterization and Assessment.

This research focuses on the plant-mediated green synthesis process to produce gold nanoparticles (Au NPs) using upland cress (Barbarea verna), as various biomolecules within the upland cress act as both reducing and capping agents. The synthesized gold nanoparticles were thoroughly characterized using UV-vis spectroscopy, surface charge (zeta potential) analysis, scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray diffraction (XRD). The results indicated the synthesized Au NPs are spherical and well-dispersed with an average diameter ~11 nm and a characteristic absorbance peak at ~529 nm. EDX results showed an 11.13% gold content. Colloidal Au NP stability was confirmed with a zeta potential (ζ) value of -36.8 mV. X-ray diffraction analysis verified the production of crystalline face-centered cubic gold. Moreover, the antimicrobial activity of the Au NPs was evaluated using Gram-negative Escherichiacoli and Gram-positive Bacillus megaterium. Results demonstrated concentration-dependent antimicrobial properties. Lastly, applications of the Au NPs in catalysis and biomedicine were evaluated. The catalytic activity of Au NPs was demonstrated through the conversion of 4-nitrophenol to 4-aminophenol which followed first-order kinetics. Cellular uptake and cytotoxicity were evaluated using both BMSCs (stem) and HeLa (cancer) cells and the results were cell type dependent. The synthesized Au NPs show great potential for various applications such as catalysis, pharmaceutics, and biomedicine.

From waste plastics to industrial raw materials: A life cycle assessment of mechanical plastic recycling practice based on a real-world case study.

Mechanical recycling of waste plastics is an environmental solution to the problem of waste plastic disposal, and has already become a common practice in industry. However, limited information can be found on either the industralised plastic recycling or the recycled materials, despite the use of recycled plastics has already extended to automobile production. This study investigates the life cycle environmental impacts of mechanical plastic recycling practice of a plastic recycling company in China. Waste plastics from various sources, such as agricultural wastes, plastic product manufacturers, collected solid plastic wastes and parts dismantled from waste electric and electronic equipments, are processed in three routes with products end up in different markets. The results of life cycle assessments show that the extrusion process has the largest environmental impacts, followed by the use of fillers and additives. Compared to production of virgin plastics and composites, the mechanical recycling is proved to be a superior alternative in most environmental aspects. Substituting virgin plastic composites with recycled plastic composites has achieved the highest environmental benefits, as virgin composite production has an impact almost 4 times higher that of the recycled composite production in each ReCiPe endpoint damage factor. Sensitivity analysis shows that the coverage of collecting network contribute affect little to overall environmental impact, and centralisation plays an important role in reducing overall environmental impacts. Among the fillers and additives, impact modifiers account for the most significant contributions to the environmental impacts of recycled composites. This study provides necessary information about the existing industrialised plastic recycling practice, and recommendations are given. Research implications are presented with the purpose to achieve higher substitution rate and lower environmental impact.

Chitosan-Decorated Doxorubicin-Encapsulated Nanoparticle Targets and Eliminates Tumor Reinitiating Cancer Stem-like Cells.

Tumor reinitiating cancer stem-like cells are responsible for cancer recurrence associated with conventional chemotherapy. We developed a doxorubicin-encapsulated polymeric nanoparticle surface-decorated with chitosan that can specifically target the CD44 receptors of these cells. This nanoparticle system was engineered to release the doxorubicin in acidic environments, which occurs when the nanoparticles are localized in the acidic tumor microenvironment and when they are internalized and localized in the cellular endosomes/lysosomes. This nanoparticle design strategy increases the cytotoxicity of the doxorubicin by six times in comparison to the use of free doxorubicin for eliminating CD44(+) cancer stem-like cells residing in 3D mammary tumor spheroids (i.e., mammospheres). We further show these nanoparticles reduced the size of tumors in an orthotopic xenograft tumor model with no evident systemic toxicity. The development of nanoparticle system to target cancer stem-like cells with low systemic toxicity provides a new treatment arsenal for improving the survival of cancer patients.

Thermally responsive nanoparticle-encapsulated curcumin and its combination with mild hyperthermia for enhanced cancer cell destruction.

In this study, thermally responsive polymeric nanoparticle-encapsulated curcumin (nCCM) was prepared and characterized. The nCCM is ≈ 22 and 300 nm in diameter at 37 and 22 °C, respectively. The smaller size of the nCCM at 37 °C was found to significantly facilitate its uptake in vitro by human prostate adenocarcinoma PC-3 cancer cells. However, the intracellular nCCM decreases rapidly (rather than plateaus) after reaching its peak at ≈ 1.5 h during a 3-day incubation of the PC-3 cells with nCCM. Moreover, a mild hyperthermia (with negligible cytotoxicity alone) at 43 °C applied between 1 and 1.5 h during the 3-day incubation not only increases the peak uptake but also alters intracellular distribution of nCCM (facilitating its delivery into cell nuclei), which helps to retain a significantly much higher level of intracellular curcumin. These effects of mild hyperthermia could be due in part to the thermal responsiveness of the nCCM: they are more positively charged at 43 °C and can be more easily attracted to the negatively charged nuclear membrane to enter nuclei as a result of electrostatic interaction. Ultimately, a combination of the thermally responsive nCCM and mild hyperthermia significantly enhances the anticancer capability of nCCM, resulting in a more than 7-fold decrease in its inhibitory concentration to reduce cell viability to 50% (IC50). Further mechanistic studies suggest injury pathways associated with heat shock proteins 27 and 70 should contribute to the enhanced cancer cell destruction by inducing cell apoptosis and necrosis. Overall, this study demonstrates the potential of combining mild hyperthermia and thermally responsive nanodrugs such as nCCM for augmented cancer therapy.

A characterization of the Manduca sexta serotonin receptors in the context of olfactory neuromodulation.

Neuromodulation, the alteration of individual neuron response properties, has dramatic consequences for neural network function and is a phenomenon observed across all brain regions and taxa. However, the mechanisms underlying neuromodulation are made complex by the diversity of neuromodulatory receptors expressed within a neural network. In this study we begin to examine the receptor basis for serotonergic neuromodulation in the antennal lobe of Manduca sexta. To this end we cloned all four known insect serotonin receptor types from Manduca (the Ms5HTRs). We used phylogenetic analyses to classify the Ms5HTRs and to establish their relationships to other insect serotonin receptors, other insect amine receptors and the vertebrate serotonin receptors. Pharmacological assays demonstrated that each Ms5HTR was selective for serotonin over other endogenous amines and that serotonin had a similar potency at all four Ms5HTRs. The pharmacological assays also identified several agonists and antagonists of the different Ms5HTRs. Finally, we found that the Ms5HT1A receptor was expressed in a subpopulation of GABAergic local interneurons suggesting that the Ms5HTRs are likely expressed heterogeneously within the antennal lobe based on functional neuronal subtype.

Degradable rosin-ester-caprolactone graft copolymers.

We have carried out the synthesis of side-chain rosin-ester-structured poly(ε-caprolactone) (PCL) through a combination of ring-opening polymerization and click chemistry. Rosin structures are shown to be effectively incorporated into each repeat unit of caprolactone. This simple and versatile methodology does not require sophisticated purification of raw renewable biomass from nature. The rosin properties have been successfully imparted to the PCL polymers. The bulky hydrophenanthrene group of rosin increases the glass-transition temperature of PCL by >100 °C, whereas the hydrocarbon nature of rosin structures provides PCL excellent hydrophobicity with contact angle very similar to polystyrene and very low water uptake. The rosin-containing PCL graft copolymers exhibit full degradability and good biocompatibility. This study illustrates a general strategy to prepare a new class of renewable hydrocarbon-rich degradable biopolymers.

Synthesis and characterization of thermally responsive Pluronic F127-chitosan nanocapsules for controlled release and intracellular delivery of small molecules.

In this study, we synthesized empty core-shell structured nanocapsules of Pluronic F127 and chitosan and characterized the thermal responsiveness of the nanocapsules in size and wall-permeability. Moreover, we determined the feasibility of using the nanocapsules to encapsulate small molecules for temperature-controlled release and intracellular delivery. The nanocapsules are ∼37 nm at 37 °C and expand to ∼240 nm when cooled to 4 °C in aqueous solutions, exhibiting >200 times change in volume. Moreover, the permeability of the nanocapsule wall is high at 4 °C (when the nanocapsules are swollen), allowing free diffusion of small molecules (ethidium bromide, MW = 394.3 Da) across the wall, while at 37 °C (when the nanocapsules are swollen), the wall-permeability is so low that the small molecules can be effectively withheld in the nanocapsule for hours. As a result of their thermal responsiveness in size and wall-permeability, the nanocapsules are capable of encapsulating the small molecules for temperature-controlled release and intracellular delivery into the cytosol of both cancerous (MCF-7) and noncancerous (C3H10T1/2) mammalian cells. The cancerous cells were found to take up the nanocapsules much faster than the noncancerous cells during 45 min incubation at 37 °C. Moreover, toxicity of the nanocapsules as a delivery vehicle was found to be negligible. The Pluronic F127-chitosan nanocapsules should be very useful for encapsulating small therapeutic agents to treat diseases particularly when it is combined with cryotherapy where the process of cooling and heating between 37 °C and hypothermic temperatures is naturally done.

Preferential vitrification of water in small alginate microcapsules significantly augments cell cryopreservation by vitrification.

The morphological changes of small (approximately 100 microm) alginate microcapsules and the biophysical alterations of water in the microcapsules during cryopreservation were studied using cryomicroscopy and scanning calorimetry. It was found that water in the small microcapsules can be preferentially vitrified over water in the bulk solution in the presence of 10% (v/v) or more dimethylsulfoxide (DMSO, a cryoprotectant), which resulted in an intact morphology of the microcapsules post cryopreservation with a cooling rate of 100 degrees Celsius/min. A small amount of Ca(2+) (up to 0.15 M) was also found to help maintain the microcapsule integrity during cryopreservation, which is attributed to the enhancement of the alginate matrix strength by Ca(2+) rather than promoting vitrification of water in the microcapsules. The preferential vitrification of water in small microcapsules was further found to significantly augment cell cryopreservation by vitrification at a low concentration of cryoprotectants (i.e., 10% (v/v)) using a small quartz microcapillary (400 microm in diameter). Therefore, the small alginate microcapsule could be a great system for protecting living cells that are highly sensitive to stresses due to freezing (i.e., ice formation) and high concentration of cryoprotectants from injury during cryopreservation.

Encapsulation of living cells in small ( approximately 100 microm) alginate microcapsules by electrostatic spraying: a parametric study.

A parametric study was performed to understand the effect of preparation parameters on size, morphology, and encapsulation efficiency (i.e., cells/microcapsule) of alginate microcapsules prepared using the electrostatic spray method. The preparation parameters studied include sodium alginate concentration, spray voltage, flow rate, and cell density. It was found that both the flow rate and spray voltage have a significant impact on microcapsule size while the microcapsule morphology is greatly influenced by both the sodium alginate concentration and spray voltage. To obtain small ( approximately 100 mum) cell-loaded microcapsules with good morphology (i.e., round in shape and uniform in size) and high encapsulation efficiency (>5 cells/microcapsule), the optimal ranges of spray voltage, flow rate, alginate concentration, and cell density are from 1.6-1.8 kV, 1.5-3 ml/h, >1.5% (w/v), and (3-5)x10(6) cells/ml, respectively. Under optimal preparation conditions, cells were found to survive the microencapsulation process well.