The Combinations Chitosan-Pam3CSK4 and Chitosan-Monophosphoryl Lipid A: Promising Immune-Enhancing Adjuvants for Anticaries Vaccine PAc

Toll-like receptors and Streptococcus mutans: An updated review article

It has been reported that toll-like receptors (TLRs) are the main innate immune receptors that recognize gram-positive pathogen-associated molecular patterns (PAMPs). The molecules can induce expression of the innate immune-related molecules that are essential against the bacteria. Streptococcus mutans (S. mutans) is a potential caries-associated pathogen, and innate immunity plays a key role in inhibiting its development and the progression of inflammatory responses. Recently, the roles played by TLRs against S. mutans and the induction of inflammatory responses were evaluated by several investigations. This review article discusses updated information regarding the roles played by TLRs and their potential therapeutic effects against S. mutans.

Chitosan as a biomaterial for the prevention and treatment of dental caries: antibacterial effect, biomimetic mineralization, and drug delivery

Dental caries is a chronic, progressive disease caused by plaque, influenced by multiple factors and can damage the hard tissues of the teeth. In severe cases, it can also lead to the onset and development of other oral diseases, seriously affecting patients' quality of life. The creation of effective biomaterials for the prevention and treatment of dental caries has become one of the relentless goals of many researchers, with a focus on inhibiting the production of cariogenic plaque and retaining beneficial bacteria, guiding and promoting the reconstruction of dental hard tissues, and delaying the progression of existing caries. Chitosan is a natural cationic polymer extracted from the shells of crustaceans and shellfish. Since its discovery, chitosan has shown to have various biological functions such as antibacterial, biomimetic mineralization, drug delivery, etc., making it one of the most promising biopolymers for new caries prevention and materials of prostheses. Therefore, this article provides an overview of the anti-caries applications of chitosan, which mainly covers the basic research on the application of chitosan in caries prevention and treatment since 2010, with a focus on categorizing and summarizing the following characteristics of chitosan as a caries prevention material, including its antibacterial effect, biomimetic mineralization effect and delivery ability of caries prevention drugs and vaccines. It also explores the limitations of current research on chitosan as a caries prevention biomaterial and the difficulties that need to be focused on and overcome in the future to provide theoretical reference for the clinical implementation of chitosan as a caries prevention biomaterial.

A Nanoparticle-Based Anticaries Vaccine Enhances the Persistent Immune Response To Inhibit Streptococcus mutans and Prevent Caries

Caries vaccines have been identified as a good strategy for the prevention of caries through the mechanism of inoculation against Streptococcus mutans, which is the main etiological bacterium causing caries. Protein antigen c (PAc) of S. mutans has been administered as an anticaries vaccine but shows relatively weak immunogenicity to elicit a low-level immune response. Here, we report a zeolitic imidazolate framework-8 nanoparticle (ZIF-8 NP)-based adjuvant with good biocompatibility, pH responsiveness, and high loading performance for PAc that was used as an anticaries vaccine. In this study, we prepared a ZIF-8@PAc anticaries vaccine and investigated the immune responses and anticaries efficacy induced by this vaccine in vitro and in vivo. ZIF-8 NPs substantially improved the internalization of PAc in lysosomes for further processing and presentation to T lymphocytes. In addition, significantly higher IgG antibody titers, cytokine levels, splenocyte proliferation indices, and percentages of mature dendritic cells (DCs) and central memory T cells were detected in mice subcutaneously immunized with ZIF-8@PAc than in mice subcutaneously immunized with PAc alone. Finally, rats were immunized with ZIF-8@PAc, and ZIF-8@PAc elicited a strong immune response to inhibit colonization by S. mutans and improve prophylactic efficacy against caries. Based on the results, ZIF-8 NPs are promising as an adjuvant for anticaries vaccine development. IMPORTANCE Streptococcus mutans is the main etiologic bacterium of dental caries, whose protein antigen c (PAc) has been administered as an anticaries vaccine. However, the immunogenicity of PAc is relatively weak. To improve the immunogenicity of PAc, ZIF-8 NP was used as an adjuvant, and the immune responses and protective effect elicited by ZIF-8@PAc anticaries vaccine were evaluated in vitro and in vivo. The findings will help in prevention of dental caries and provide new insight for the development of anticaries vaccine in the future.

Chitosan-Based Nanomaterial as Immune Adjuvant and Delivery Carrier for Vaccines

With the support of modern biotechnology, vaccine technology continues to iterate. The safety and efficacy of vaccines are some of the most important areas of development in the field. As a natural substance, chitosan is widely used in numerous fields-such as immune stimulation, drug delivery, wound healing, and antibacterial procedures-due to its good biocompatibility, low toxicity, biodegradability, and adhesion. Chitosan-based nanoparticles (NPs) have attracted extensive attention with respect to vaccine adjuvants and delivery systems due to their excellent properties, which can effectively enhance immune responses. Here, we list the classifications and mechanisms of action of vaccine adjuvants. At the same time, the preparation methods of chitosan, its NPs, and their mechanism of action in the delivery system are introduced. The extensive applications of chitosan and its NPs in protein vaccines and nucleic acid vaccines are also introduced. This paper reviewed the latest research progress of chitosan-based NPs in vaccine adjuvant and drug delivery systems.

Bibliometric Analysis of the Current Landscape of Global Scientific Production on the Development of Vaccines against Dental Caries

Objective. To perform a bibliometric analysis of the scientific research on the development of vaccines against dental caries. Methods. An extraction of the scientific production published on the development of vaccines against dental caries between 2011 and 2020 was carried out from the Scopus database. Microsoft Excel was used for the elaboration of tables and SciVal for the bibliometric analysis of the data, which were divided into indicators of production, impact, and collaboration. Finally, VOSviewer was used for co-occurrence analysis of keywords and collaborative networks. Results. 106 studies were retrieved from the Scopus database, which were conducted on the development of dental caries vaccines within the years 2011–2020. Wuhan University, in China, was the university with the highest scientific production on the subject, with 4 publications. Regarding the most productive journals, the first place was occupied by the Journal of Dental Research with 7 publications. Regarding the most productive journals, the first place was occupied by the Journal of Dental Research with 7 publications. The highest percentage of the documents analyzed was in quartile 1 journals and in the national collaboration pattern. Conclusion. Most of the manuscripts regarding the development of vaccines against dental caries were published in China and in Q1 quartile journals. In addition, Yan Huimin, Yang Jingyi, Zhou Dihan, Yang Yi, Li Yuhong and Fan Mingwen were found to top the list of most productive authors. The Journal of Dental Research was also identified as the most productive and cited journal.

Carbohydrate-based adjuvants

Carbohydrate adjuvants are safe and biocompatible compounds usable as sustained delivery systems and stimulants of ongoing humoral and cellular immune responses, being especially suitable for the development of vaccines against intracellular pathogens where alum is useless. The development of new adjuvants is difficult and expensive, however, in the last two years, seven new carbohydrate-based adjuvants have been patented, also there are twelve ongoing clinical trials of vaccines that contain carbohydrate-based adjuvants, as well as numerous publications on their mechanism of action and safety. More research is necessary to improve the existent adjuvants and develop innovative ones.