A Study of Hydrophobically Modified Pullulan Nanoparticles with Different Hydrophobic Densities on the Effect of Anti-Colon Cancer Cell Efficiency

pH-responsive self-assembled nanoparticles for tumor-targeted drug delivery

Recent advances in the field of drug delivery have opened new avenues for the development of novel nanodrug delivery systems (NDDS) in cancer therapy. Self-assembled nanoparticles (SANPs) based on tumour microenvironment have great advantages in improving antitumor effect, and pH-responsive SANPs prepared by the combination of pH-responsive nanomaterials and self-assembly technology can effectively improve the efficacy and reduce the systemic toxicity of antitumor drugs. In this review, we describe the characteristics of self-assembly and its driving force, the mechanism of pH-responsive NDDS, and the nanomaterials for pH-responsive SANPs type. A series of pH-responsive SANPs for tumour-targeted drug delivery are discussed, with an emphasis on the relation between structural features and theranostic performance.

Preparation of pH-sensitive carboxymethyl chitosan nanoparticles loaded with ginsenoside Rb1 and evaluation of drug release in vitro

Oral absorption of ginsenoside Rb1 (Rb1) is often hindered by the gastrointestinal tract. Carboxymethyl chitosan deoxycholic acid loaded with ginsenoside Rb1 nanoparticles (CMDA@Rb1-NPs), were prepared as a delivery system using a self-assembly technique with amphipathic deoxycholic acid grafted carboxymethyl chitosan as the carrier, which improved the stability and embedding rate of Rb1. In addition, the CMDA@Rb1-NPs was encapsulated with sodium alginate by ion crosslinking method with additional layer (CMDAlg@Rb1-NPs). Scanning electron microscopy showed that the nanoparticles were spherical, evenly distributed, smooth and without obvious adhesion. By evaluating drug loading, entrapment efficiency, the encapsulation efficiency of Rb1 increased from 60.07 % to 72.14 % after grafting deoxycholic acid improvement and optimization. In vitro release results showed that the cumulative release of Rb1 by CMDAlg-NPs showed a pH dependent effect, which was <10 % in simulated gastric juice with pH 1.2, completely released with pH 7.4 for about 48 h. In addition, Rb1 and CMDAlg@Rb1-NPs had inhibitory effects on A549 cells, and the inhibitory effect of CMDAlg@Rb1-NPs was better. Therefore, all results indicated that CMDA/Alg@Rb1 nanoparticles might be a novel drug delivery system to improve the stability and embedding rate of Rb1, and has the potential to be applied in oral pharmaceutical preparations.

The Application of Sensitive Nano-Confined Nanoparticle System Using siRNA Targeting Extracellular Signal-Regulated Kinase (ERK)/Mitogen-Activated Protein Kinase (MAPK) Pathway in Gastrointestinal Cancer

In this study we tried to develop a Sensitive Nano-Confined Nanoparticles (S-NCN) system using siRNA against Programmed death-ligand 1 (PDL-1) and Polo Like Kinase 1 (Plk1) to treat gastrointestinal cancer. In this regard, we first synthesized the corresponding materials, prepared the S-NCN system, and verified its functionality. Subsequently, we demonstrated in vitro that S-NCN delivery of siPlk1 could effectively downregulate the expression of Plk1 gene in GC1436 cells and lead to significant apoptosis of tumor cells. Xenografted gastrointestinal cancer model mice were used to evaluate the in vivo efficacy of the nanoparticle. We have demonstrated that the developed S-NCN system can efficiently bind siRNA and deliver it into target tumor cells, solving the main obstacle of siRNA delivery in vivo and effectively silencing target genes with a very potential delivery option.