An overview of nanogel-based vaccines

ABSTRACT

Introduction: The development of more efficacious vaccines, especially subunit vaccines administered via non-invasive routes, is a priority in vaccinology. Nanogels are materials that can meet the requirements to serve as efficient vaccine delivery vehicles (in terms of thermo-sensitivity, biocompatibility, and pH-responsiveness; among others); thus there is a growing interest in exploring the potential of nanogels for vaccine development.

Areas covered: Herein, a critical analysis of nanogel synthesis methodologies is presented and nanogel-based vaccines under development are summarized and placed in perspective. Promising vaccine candidates based on nanogels have been reported for cancer, obesity, and infectious diseases (mainly respiratory diseases). Some of the candidates were administered by mucosal routes which are highly attractive in terms of simple administration and induction of protective responses at both mucosal and systemic levels.

Expert opinion: The most advanced models of nanogel-based vaccines comprise candidates against cancer, based on cholesteryl pullulan nanogels evaluated in clinical trials with promising findings; as well as some vaccines against respiratory pathogens tested in mice thus far. Nonetheless, the challenge for this field is advancing in clinical trials and proving the protective potential in test animals for many other candidates. Implementing green synthesis approaches for nanogels is also required.

KEYWORDS:

• Nanogels
• cancer
• mucosal vaccines
• antigen uptake
• toxicity
• vaccine cost
• pH responsiveness
• mechanical properties
• biodegradability

Article Highlights

• Developing efficacious and attractive vaccines partially depends on efficient delivery vehicles upon administration by non-invasive routes.

• Nanogels can be applied in vaccine development thanks to their biocompatibility, simple functionalization, and compatibility with mucosal immunization approaches.

• Methodologies for the synthesis of nanogels include chemical and physical crosslinking. Nonetheless, green syntheses approaches for nanogels have been narrowly explored.

• The state of the art on developing nanogels-based vaccines is provided and placed in perspective. Although preclinical evaluations have led to promising findings and some candidates are under clinical evaluation, there is a need for completing toxicological assessments and initiating clinical trials for the most promising candidates.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

S Rosales-Mendoza and C Angulo were supported by CONACYT/Mexico (grant 256063 and grant FC2016/2820).