Construction of novel amphiphilic chitosan-polylactide graft copolymer nanodroplets for contrast enhanced ultrasound tumor imaging

Abstract

In this experiment, a new amphiphilic chitosan-poly(lactide) graft copolymer was synthesized and characterized by IR, 1H-NMR, XRD, TGA. The obtained chitosan-poly (lactide) graft copolymer was used as the matrix material to prepare nanodroplets (NDs) encapsulating with liquid PFP by double-emulsion and solvent evaporation method. The resulting NDs were characterized by photon correlation spectroscopy and transmission electron microscopy (TEM). The biocompatibility was explored by cytotoxicity assay, cell migration assay and blood biochemistry analysis. The experiments of ultrasonic imaging in vitro and in vivo were carried out with a B-mode clinical ultrasound imaging system. The results of FI-IR and 1H-NMR confirmed the successful grafting reaction of polylactic acid(PLLA) to chitosan with a graft rate of 365%. The average size of the NDs was 101.1 ± 2.7 nm, with the polydispersity index (PDI) of 0.127 ± 0.020, and the zeta potential was −31.8 ± 1.5 mV. From the TEM results, NDs were highly dispersed and had a spherical shape with a distinct capsule structure. The NDs exhibited good stability during storage at 4°C. The NDs solution with different concentrations did not affect cell growth and showed good biocompatibility in cytotoxicity, cell migration and blood biochemistry studies. Under the irradiation of ultrasonic waves, the NDs formed an ultrasonic high signal, which could significantly enhance the ultrasound imaging of tumor tissue in vivo. Taken together, the NDs hold great potential for ultrasound imaging as a nanosized contrast agent.

Ursolic acid loaded tri-block copolymer nanoparticles based on triphenylphosphine for mitochondria-targeted cancer therapy

“…The nanoparticles were prepared by the emulsionsolvent evaporation method [21]. TPP-PAEEP-PEG-PLLA (0.0300 g) was dissolved in 3 ml of dichloromethane, and UA (0.0030 g) was dissolved in 1 ml of anhydrous ethanol.…”

“…Currently, polymers, especially biodegradable polymers, play an indispensable role in drug delivery systems and have become an attractive research focus [18,19]. Due to its environmentally friendly and nontoxic degradable properties, polylactic acid (PLLA) is widely used in the human body and in many fields, such as biomedicine, environmental engineering, and food packaging, etc [20][21][22]. However, nanocarriers prepared with PLLA are highly susceptible to recognition and phagocytosis by the reticuloendothelial system because of their hydrophobic surface.…”

Lactoferrin-Conjugated Polylactic Acid Nanobubbles Encapsulated Perfluoropentane as a Contrast Agent for Ultrasound/Magnetic Resonance Dual-Modality Imaging

“…Gases of PFP encapsulated in the nanobubbles stabilized by elastic polymer walls are compressible. Under the action of ultrasound, the nanoscale bubbles grow and shrink in a rhythmic fashion, which will generate harmonic signals and contrast-enhanced imaging would be acquired [39,40].…”

Preparation, characterization and antioxidant activity of polysaccharides copper from Qingzhuan dark tea

“…The presents study aims to perform the structural characterization and investigate the antioxidant activity of TPS-Cu. In this study, the structure and physical properties of TPS-Cu were characterized by high performance gel filtration chromatography, atomic absorption spectroscopy, ultraviolet spectroscopy (UV), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), atomic mechanics microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) (Wang et al, 2021). Additionally, a series of in vitro experiments was measured to the antioxidant activity of the TPS-Cu complex (Kaska et al, 2021).…”