Modulation of Chitosan-TPP Nanoparticle Properties for Plasmid DNA Vaccines Delivery

Abstract

Nucleic acid vaccines have become a revolutionary technology to give a fast, safe, cost-effective and efficient response against viral infections, such as SARS-CoV-2 or Human papillomavirus (HPV). However, to ensure their effectiveness, the development of adequate methods to protect, carry, and deliver nucleic acids is fundamental. In this work, nanoparticles (NPs) of chitosan (CS)-tripolyphosphate (TPP)-plasmid DNA (pDNA) were thoroughly modulated and characterized, by measuring the charge and size through dynamic light scattering (DLS) and morphology by scanning electron microscopy (SEM). Stability, cytotoxicity and cellular uptake of NPs were also evaluated. Finally, the effect of polyplexes on the expression of HPV E7 antigen in human fibroblast and RAW cells was investigated through polymerase chain reaction (PCR) and real-time PCR. The results showed NPs with a spherical/oval shape, narrow size distribution <180 nm and positive zeta potentials (>20 mV) and good stability after one month of storage at 4 °C in formulation buffer or when incubated in culture medium and trypsin. In vitro studies of NPs cytotoxicity revealed that the elimination of formulation buffers led to an improvement in the rate of cell viability. The E7 antigen transcription was also increased for NPs obtained with high pDNA concentration (60 μg/mL). The analyzed CS-TPP-pDNA polyplexes can offer a promising vehicle for nucleic acid vaccines, not only in the prevention or treatment of viral infections, but also to fight emergent and future pathogens.

Preparation and Characterization of Patuletin-Loaded Chitosan Nanoparticles with Improved Selectivity and Safety Profiles for Anticancer Applications

“…Te 2 nd stage is corresponding to the CS and TPP ionic bond destruction and disintegrated nanoparticles [37] at 272 °C. Te 3 rd stage at 412 °C may be related to the thermal degradation of the main polymer backbone [36,38]. For PT-CS-NP, three stages of mass loss were also detected.…”

“…Te nanoparticles had a compact structure, a nearly spherical form, and a heterogeneous morphology, as seen by TEM pictures. Furthermore, a solid core surrounded by the polymer was found, which most likely did not interact throughout the NP formation [35,36]; on the other hand, PT-CS-NP shows small particles due to the presence of PT with a more angular structure than spherical, and the size varies between 4 and 11 nm with average size � 6.168 nm that are suitable for drug delivery application.…”

Optimization of the Redox-Sensitive Doxorubicin Loaded Chitosan-based Nanoparticles by Box–Behnken Experimental Design

“…Cs-CysNPs-DOX was prepared by the ionic gelation method, as described previously with some modifications [19]. The NPs were synthesized by electrostatic interaction between the cationic Cs-Cys copolymer and TPP as an anionic cross-linking agent.…”

Natural Polymeric Composites Derived from Animals, Plants, and Microbes for Vaccine Delivery and Adjuvant Applications: A Review

“…Chitosan’s anti-viral activities have been known to be impacted by these key factors: molecular weight and degree of acetylation and substitution [ 29 ]. Recently, a novel formulation of NPs of chitosan-tripolyphosphate (TPP) using the ionotropic gelation method to deliver plasmid DNA (pDNA) vaccines for cervical cancer was investigated [ 30 ]. The results showed good stability of NPs, high pDNA encapsulation efficiency rate, improved rate of cell viability during NPs cytotoxicity test in vitro, and an increase in E7 antigen transcription, the oncoprotein of high-risk human papillomavirus (HPV).…”