Effects of cyclic polylactate (CPL) on the growth of cloned leukemic cells in vitro

Preparation and in vitro tumor growth inhibitory effect of oligo (L-lactate) nanoparticles

Oligo L-lactates (oligolactates) that have low molecular weights less than 2000 have been reported to inhibit tumor growth and extend the survival of experimental animals. Because oligolactates are scarcely soluble in water, they require a solvent or a solubilizing agent, such as a surfactant, to be dissolved in water. However, these agents are generally cytotoxic, an in vitro assay appropriate to evaluate the inhibitory effect on tumor growth has not been developed yet. Here, we prepared a solid nanodispersion of oligolactates using an oil-in-water emulsion solvent evaporation method to evaluate its tumor inhibitory activity in vitro without a solvent or surfactant. Polyol solutions containing polyvinyl alcohol (PVA) were used as a continuous phase. The formation of nanoparticles depended on the concentrations of polyol and PVA in the continuous phase. The nanoparticles with a particle size of approximately 100 nm were obtained using 10-15% PVA and 60% propylene glycol. The obtained aqueous nanodispersion of oligolactates inhibited the growth of B16-BL6 melanoma cells in vitro, whereas the medium alone did not affect tumor cell growth. Therefore, oligo(L-lactate) nanoparticles may be useful in the research and development of oligolactates as a remedy for cancer.

Design of naturally inspired jellyfish-shaped cyclopolylactides to manage osteosarcoma cancer stem cells fate

We report the synthesis, characterization and biological profile of new bis-triazoled cyclopolylactides (c-PLA, c-PLA-FA, c-PLA-Rhod) obtained by an optimized combination of ROP and click chemistry reactions. Cyclo-PLA having a number average molecular weight of 6000 g mol^-1 and a polydispersity index of 1.52 was synthetized by click ring-closure of well-defined α,ω-heterodifunctional linear precursors, followed by quaternarization of N₃-triazole nodes, and subsequent CuAAC with azido-folate and azido-rhodamine yielding jellyfish-shaped c-PLA-FA and c-PLA-Rhod. Salinomycin (Sal) was loaded into jellyfish-shaped c-PLA-FA and c-PLA-Rhod nanoparticles (NPs) by nanoprecipitation, with a good encapsulation efficiency (79% and 84%, respectively) and loading content (7.1% and 7.6%, respectively). The biological studies focused on their antiproliferative effects on osteosarcoma bulk MG63 and cancer stem cells (CSCs). The cycloPLA-based NPs, with a size ranging between 125 and 385 nm, killed CSCs and MG63, with a higher efficacy on CSCs; they (unloaded or Sal-loaded) evoked on CSCs a cellular response similar to the payload, with a higher effect than the free Sal. Internalization studies indicated a fast cellular uptake (within 2 h) and sarcospheres remained fluorescent till 72 h. To the best of our knowledge, this is the first study reporting anti-CSCs properties of cycloPLA with jellyfish architecture and we believe could contribute to the development of effective strategies for osteosarcoma targeting.

Cell death in HeLa mediated by thermoplastic polyurethane with co-immobilized IFN-γ plus TNF-α

In order to prohibit the toxicity of free IFN-γ plus TNF-α in treating human cervical cancer HeLa cells, two kinds of thermoplastic polyurethane (polyester/polyether) biomaterials with co-immobilized IFN-γ plus TNF-α on the surfaces are prepared. The programmed cell death of HeLa induced by these biomaterials is investigated. The surface modification of these biomaterials with co-immobilized IFN-γ plus TNF-α is performed by the photo-immobilization method, and the surface structures are characterized by various techniques. The cell morphology, cell mortality, cell cycle arrest, and functional status of caspases, upon the treatment by these biomaterials, are characterized. The results show that the as-prepared biomaterials have high inhibition activity against the growth of HeLa cells. The HeLa cells mediated by the two kinds of biomaterials are mainly arrested in the G(1) phase, while those cells mediated directly by free IFN-γ plus TNF-α are mainly arrested in the S phase. It is suggested that the programmed cell death mechanism induced by these two kinds of biomaterials is both caspase-dependent and caspase-independent. Our data provide the knowledge of microscopic surface structures and cell biology basis for synthesizing the thermoplastic polyurethane biomaterials with co-immobilized IFN-γ plus TNF-α, which are promising for novel therapeutics (e.g. drug cup) design for cervical cancer patients.