Chitosan-based nanoscale delivery systems in hepatocellular carcinoma: Versatile bio-platform with theranostic application

The field of nanomedicine has provided a fresh approach to cancer treatment by addressing the limitations of current therapies and offering new perspectives on enhancing patients' prognoses and chances of survival. Chitosan (CS) is isolated from chitin that has been extensively utilized for surface modification and coating of nanocarriers to improve their biocompatibility, cytotoxicity against tumor cells, and stability. HCC is a prevalent kind of liver tumor that cannot be adequately treated with surgical resection in its advanced stages. Furthermore, the development of resistance to chemotherapy and radiotherapy has caused treatment failure. The targeted delivery of drugs and genes can be mediated by nanostructures in treatment of HCC. The current review focuses on the function of CS-based nanostructures in HCC therapy and discusses the newest advances of nanoparticle-mediated treatment of HCC. Nanostructures based on CS have the capacity to escalate the pharmacokinetic profile of both natural and synthetic drugs, thus improving the effectiveness of HCC therapy. Some experiments have displayed that CS nanoparticles can be deployed to co-deliver drugs to disrupt tumorigenesis in a synergistic way. Moreover, the cationic nature of CS makes it a favorable nanocarrier for delivery of genes and plasmids. The use of CS-based nanostructures can be harnessed for phototherapy. Additionally, the incur poration of ligands including arginylglycylaspartic acid (RGD) into CS can elevate the targeted delivery of drugs to HCC cells. Interestingly, smart CS-based nanostructures, including ROS- and pH-sensitive nanoparticles, have been designed to provide cargo release at the tumor site and enhance the potential for HCC suppression.

A novel iron-conjugated acid-modified chitosan derivatives as an oral phosphate binding agent to improve phosphorus adsorption efficacy in vitro and in vivo, synthesis and their characterization

Current phosphate binders used for hyperphosphatemia treatment need large daily dose which make patients' compliance worse and the therapeutic efficacy may not conform the expectation. In this study, three polyacid modified iron-based chitosan derivatives were developed as an oral phosphate binding agent to improve phosphorus adsorption efficacy. The result showed that modification of chitosan by citric acid (CA) could facilitate the conjugation of iron by two folds (272.0 ± 12.1-315.3 ± 20.5 mg Fe/g vs. 141.0 ± 4.9-156.5 ± 8.3 mg Fe/g). All of these iron-based acid-modified chitosan had acceptable safety with cell viability >75% in the concentration up to 250 μg/mL. The stability in terms of iron release in pH 1.0 for 2 h was in the order of DPCS-NAc-CA-Fe (8.9 ± 2.3%) < DPCS-CA-Fe (19.1 ± 4.1%) < DADPCS-CA-Fe (24.6 ± 2.6%) indicating DPCS-NAc-CA-Fe was the most stable one. These iron-based acid-modified chitosan derivatives efficiently adsorbed 255.7 ± 11.3-271.2 ± 19.3 mg of phosphate especially in simulated gastro pH 1.0 in vitro. Furthermore, oral administration of DPCS-NAc-CA-Fe significantly lowered serum phosphorus level from 5.82 ± 0.45 mg/dL to 4.84 ± 0.56 mg/dL (p < 0.01) at 0.25% low feeding dose for 3 weeks without losing of weight, appetite, and activity of Wistar rats.

In situ dual-crosslinked nanoparticles for tumor targeting gene delivery

The instability of gene delivery systems and their "off-target" features are among the major hurdles in gene therapy. In this study, a facile fabrication platform is constructed to endow the gene delivery system with high stability in the circulation system and achieve targeted delivery of plasmid DNA (pDNA) into cancer cells. Aldehyde groups-bearing hyaluronic acid (HA-CHO) is initially synthesized through oxidation, and is then shielded on polyethylenimine/DNA (PEI/DNA) complex particles to form dual-crosslinked nanoparticles in situ. These nanoparticles simultaneously possess electrostatic and chemical crosslinks between outer layers and cores. The dual-crosslinking system further offers the following advantages when used for gene delivery. First, the two different in situ crosslinking routes strengthen nanoparticle stability. Second, targeting ligands on HA layers mediate specific recognition toward cancer cells. Cell and animal experiments demonstrate that the as-prepared complex particles exhibit enhanced stability in serum and excellent long circulation behavior in vivo. Third, the dual-crosslinked nanoparticles present good accumulation ability in tumors after intravenous injection into nude mice bearing HeLa tumors. Overall, the dual-crosslinking strategy is a promising solution for constructing an efficient gene delivery system.

STATEMENT OF SIGNIFICANCE

This manuscript focused on the in situ dual-crosslinked nanoparticles for tumor targeting pDNA delivery. The novel system is prepared by in situ shielding HA-CHO on PEI/DNA complexes. The electrostatic crosslink formed between carboxyl groups on HA-CHO and amine groups on PEI as well as the reaction between aldehyde groups on HA-CHO and amine groups on PEI contributes to the chemical crosslink. By introduction of HA-CHO on PEI/DNA complexes, they show promoting colloidal stability, enhanced cellular uptake and tumor targeting ability. The in vivo experiments further confirm the excellent ability of long circulation and tumor accumulation. Accordingly, HA-CHO2/PEI/DNA has great potential for tumor targeting antitumor therapy.