Mild Anticoagulant Effect of Heparin-Loaded Polycaprolactone Microspheres.

This development of the micro- and nanoparticle technology will bring a new momentum to drug delivery and biomedical therapy. In this case, heparin-loaded polycaprolactone microspheres (PCL-Hep MSs) were prepared by a single-step phase separation method, and characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and fourier transform infrared spectroscopy (FTIR). The hemocompatibility and anticoagulant effect of the PCL-Hep MSs were investigated for heparin loading and release study, coagulation tests, hemolysis assay, morphological changes of red blood cells, complement activation, and cytotoxicity experiments. The results showed that the PCL-Hep MSs are hemocompatible with low level of cytotoxicity. Moreover, they have the potential to be used as a mild anticoagulant compared to pure heparin.

UV-barrier poly(lactic acid) film with light-stabilized Eu complexes as filler.

The poor UV shielding property of PLA limit it further applications on food packaging. The rare-earth complex Eu(DBM)3phen converts absorbed ultraviolet (UV) light to red light, which inspires the development of new UV shielding materials. However, this complex has low photostability and decomposes easily under UV irradiation. Thus, we prepared a long-lasting rare-earth complex transluminant Eu(DBM)2(BP-2)phen by introducing BP-2 into Eu(DBM)3phen, and blended it with PLA to obtain PLA/Eu(DBM)2(BP-2)phen composite films. The test results showed that the complex could reduce the UV transmittance of PLA films by emitting luminescence and heat. The UV transmittance of the composite film with 0.5 % mass fraction decreased from 87.4 % to 7.7 %, compared to pure PLA films, and remained at 11.6 % after 12 days of UV aging. The film had long-lasting UV shielding performance, good transparency and mechanical properties. Finally, In the storage experiments of flaxseed oil, the P/E25 film effectively retarded the oxidation process of the oil.

Preparation of water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups and their micelles behavior, anticoagulant effect and cytotoxicity.

Biocompatibility of nanoparticles has been attracting great interest in the development of nanoscience and nanotechnology. Herein, the aliphatic water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups (HBPE-SO3 NPs) were synthesized and characterized. They are amphiphilic polymeric nanoparticles with hydrophobic hyperbranched polyester (HBPE) core and hydrophilic sulfonic acid terminal groups. Based on our observations, we believe there are two forms of HBPE-SO3 NPs in water under different conditions: unimolecular micelles and large multimolecular micelles. The biocompatibility and anticoagulant effect of the HBPE-SO3 NPs were investigated using coagulation tests, hemolysis assay, morphological changes of red blood cells (RBCs), complement and platelet activation detection, and cytotoxicity (MTT). The results confirmed that the sulfonic acid terminal groups can substantially enhance the anticoagulant property of HBPE, and the HBPE-SO3 NPs have the potential to be used in nanomedicine due to their good bioproperties.

Ultrasound improved immune adjuvant delivery to induce DC maturation and T cell activation.

Tumor immunotherapy has emerged as a promising approach to tumor treatment. Currently, immune adjuvant-based therapeutic modalities are rarely curative in solid tumors owing to challenges including the low permeability and extremely poor water solubility of these adjuvants, limiting their ability to effectively promote dendritic cell (DC) maturation. Herein, we employed ultrasound-mediated cavitation (UMC) to promote the delivery of Toll-like receptor agonist (R837)-loaded pH-responsive liposomes (PEOz-Lip@R837) to tumors. The tumor-associated antigens (TAAs) produced by UMC treatment exhibited vaccinal activity, particularly in the presence of immune adjuvants, together promoting the maturation of DC and inducing cytokine production. Importantly, UMC can down-regulate immune checkpoint molecules, like Cd274, Foxp3 and Ctla4, synergistically stimulating the activation and proliferation of T cells in the body to facilitate tumor treatment. This UMC-enhanced PEOz-Lip@R837 approach was able to induce a robust antitumor immune response capable of arresting primary and distant tumor growth, while also developing immunological memory, protecting against tumor rechallenge following initial tumor clearance. Overall, these results highlight a promising UMC- and pH-sensitive immune adjuvant delivery-based treatment for tumors with the potential for clinical application.

Preparation of PNIPAM-g-P (NIPAM-co-St) microspheres and their blood compatibility.

The poly(N-isopropylacrylamide)-g-poly(N-isopropylacrylamide-co-styrene) microspheres (PNNS-MSs) were prepared by an emulsifier-free emulsion polymerization method. The blood compatibility of PNNS-MSs was characterized by in vitro for coagulation tests, hemolysis assay, plasma recalcification time, complement activation, platelet activation, and cytotoxicity experiments. The results showed that the PNNS-MSs have good blood compatibility and lack cytotoxicity, which may be attributed to the formation of a strong interfacial hydration layer that result from amphiphilic molecular structure of the PNIPAM shell and minimal interaction between PNNS-MSs interfaces and blood components. The PNNS-MSs provide a promising platform of blood circulation system for early illness diagnosis and therapy.