<p>The Immunoenhancement Effects of Polyethylenimine-Modified Chinese Yam Polysaccharide-Encapsulated PLGA Nanoparticles as an Adjuvant</p>

Abstract

Background: Poly(lactic-co-glycolic acid) (PLGA) has been extensively applied for sustained drug delivery and vaccine delivery system. However, vaccines delivered by PLGA nanoparticles alone could not effectively activate antigen-presenting cells (APCs) to induce strong immune responses. Purpose: The aim of the present study was to design polyethylenimine (PEI)-modified Chinese yam polysaccharide (CYP)-encapsulated PLGA nanoparticles (CYPP-PEI) as a vaccine delivery system and evaluate the adjuvant activities in vitro and in vivo. Materials and Methods: Cationic-modified nanoparticles exhibited high antigen absorption and could be efficiently taken by APCs to enhance the immune responses. Therefore, PEI-modified CYP-encapsulated PLGA nanoparticles (CYPP-PEI) were prepared. The storage stability and effective adsorption capacity for porcine circovirus-2 (PCV-2) antigen of these antigen-absorbed nanoparticles were measured for one month. Furthermore, the adjuvant activity of CYPP-PEI nanoparticles was evaluated on macrophages in vitro and through immune responses triggered by PCV-2 antigen in vivo. Results: The PCV-2 absorbed CYPP-PEI nanoparticles showed excellent storage stability and high absorption efficiency of PCV-2 antigen. In vitro, CYPP-PEI nanoparticles promoted antigen uptake, enhanced surface molecular expressions of CD80 and CD86, and improved cytokine secretion of TNF-α, IFN-γ, and IL-12p70 in macrophages. After immunization with CYPP-PEI/PCV-2 formulation in mice, the expressions of surface activation markers on dendritic cells which located in draining lymph nodes were increased, such as MHCI, MHCII, and CD80. In addition, CYPP-PEI nanoparticles induced dramatically high PCV-2-specific IgG levels which could last for a long time and stimulated the secretion of subtype antibodies and cytokines. The results showed that CYPP-PEI could induce Th1/Th2 mixed but Th1-biased type immune responses. Conclusion: Polyethylenimine-modified Chinese yam polysaccharide-encapsulated PLGA nanoparticle was a potential vaccine delivery system to trigger strong and persistent immune responses.

A Comparison Study on Polysaccharides Extracted from Atractylodes chinensis (DC.) Koidz. Using Different Methods: Structural Characterization and Anti-SGC-7901 Effect of Combination with Apatinib

“…Recently, natural polysaccharides have attracted a great deal of attention due to their advantages in synergistic and detoxifying effects. In addition, their potential biological activities, such as, immunomodulatory, antioxidant, antitumor, anti-inflammatory, antidiabetic, and antiviral activities, are being realized [ 52 , 53 ]. However, extraction methods affect not only yield but also the bioactivity of polysaccharides [ 54 ].…”

Cationic Nanoparticle-Stabilized Vaccine Delivery System for the H9N2 Vaccine to Promote Immune Response in Chickens

“…The Chinese yam polysaccharide PLGA nanoparticles (CYPPs) were prepared by a similar procedure without PEI. Our previous study reported the particle size and ζ potential of PEI-CYPP to be 236.6 nm and +41.5 mV, while the CYPP had a particle size of 225.0 nm and a ζ potential of −20.7 mV …”

Understanding Structure–Function Relationships of Nanoadjuvants for Enhanced Cancer Vaccine Efficacy

“…Reproduced with permission. [ 60 ] Copyright 2021, Dove Medical Press Ltd. b) The structural assembly diagram of transient thermal response block copolymer nanoparticles encapsulated amphotericin B (AmpB). Reproduced with permission.…”

“…[59] Zhang et al designed polyethyleneimine (PEI) modified yam polysaccharide (CYP)-coated PLGA nanoparticles (CYPP-PEI) as a vaccine delivery system (Figure 3a). [60] And the results showed that it improved the efficiency of antigen absorption, promoting the uptake of antigen by macrophages and enhancing the activation of macrophages. It is beneficial to deliver antigen and CYP immunomodulators to lymph nodes and activate DCs, further enhancing Th1/Th2 mixed but Th1 biased immune responses in vivo.…”

“…Schematic diagram of polymer adjuvant structure assembly. a) The structural assembly diagram of polyethyleneimine (PEI) modified yam polysaccharide (CYP)-coated polylactic acid-glycolic acid copolymer (PLGA) nanoparticles (CYPP-PEI).Reproduced with permission [60]. Copyright 2021, Dove Medical Press Ltd. b) The structural assembly diagram of transient thermal response block copolymer nanoparticles encapsulated amphotericin B (AmpB).…”