Biomaterials, biological molecules, and polymers in developing vaccines

Currently, there is an increasing demand for efficacious vaccines for established and emerging infections and diseases. Vaccine formulations can comprise immunogenic antigens, adjuvants, preservatives, and stabilizers. The development of commercial prophylactic vaccines is delayed due to several challenges, such as safety of the formulation, suboptimal immunogenicity, and difficulties in scale-up and storage. Biomaterial-based vaccine candidates have risen to the challenge, successfully overcoming various limitations of traditional vaccines in preclinical and clinical trials. By applying the principles of polymer chemistry and bioscience, these biomaterial-based vaccines make use of chemically modified polymers, proteins, and hydrogels, as well as biomimetic virus-like nanoparticles and cell membranes, to achieve the desired levels of both safety and immunogenicity. Vaccines have been used to train the immune system to recognize pathogens, and prevent and treat diseases, such as cancer, for decades. However, there are continuing challenges in their manufacturing, large-scale production, and storage. Some of them also show suboptimal immunogenicity, requiring additional adjuvants and booster doses. As an alternate vaccination strategy, a new class of biomimetic materials with unique functionalities has emerged in recent years. Here, we explore the current bioengineering techniques that make use of hydrogels, modified polymers, cell membranes, self-assembled proteins, virus-like particles (VLPs), and nucleic acids to deliver and develop biomaterial-based vaccines. We also review design principles and key regulatory issues associated with their development. Finally, we critically assess their limitations, explore approaches to overcome these limitations, and discuss potential future applications for clinical translation. Vaccines have been used to train the immune system to recognize pathogens, and prevent and treat diseases, such as cancer, for decades. However, there are continuing challenges in their manufacturing, large-scale production, and storage. Some of them also show suboptimal immunogenicity, requiring additional adjuvants and booster doses. As an alternate vaccination strategy, a new class of biomimetic materials with unique functionalities has emerged in recent years. Here, we explore the current bioengineering techniques that make use of hydrogels, modified polymers, cell membranes, self-assembled proteins, virus-like particles (VLPs), and nucleic acids to deliver and develop biomaterial-based vaccines. We also review design principles and key regulatory issues associated with their development. Finally, we critically assess their limitations, explore approaches to overcome these limitations, and discuss potential future applications for clinical translation. a family of bacterial toxins comprising a single catalytically active A-subunit and a pentamer of B-subunits capable of mediating receptor binding and delivery of a toxin to the target cell. a drug or substance that can, in combination with other drugs/substances, increase the efficacy or potency of drugs. a group of immune cells that cause a cellular immune response by processing and presenting antigens on the surface for recognition by lymphocytes. molecules produced by cells and living organisms that are essential for one or more biological process. a material or a combination of materials, natural or synthetic, that are modified by the application of engineering principles so that they can be introduced into, and interact with, biological systems. the proteins that make up the shell of a virus, enclosing the virus genetic material and protecting it from degradation. an inorganic or organometallic polymer containing metal centers connected by a ligand. a type of APC that processes and presents antigens to T cells, giving rise to a cellular immune response. a globular iron storage protein made up of 24 subunits that form a nanocage with multiple metal–protein interactions. a hormone that causes the pituitary gland of the brain to release follicle-stimulating hormone and luteinizing hormone. the methods and regulations implemented to ensure the production of good-quality pharmaceutical products and to control the manufacture process to reduce variability and contamination. a particle that has a size of 1–100 nm in at least two dimensions. a class of antigens caused by mutations in the tumor cell genome that appear in tumor cells but not in normal tissues. Neoantigens show individual specificity, are highly immunogenic, and elicit stable therapeutic effects. a large, complex, and mildly immunogenic glycoprotein; a key reference protein for vaccination experiments as an antigen for immunization research. a process in which protective cells (phagocytes) engulf and degrade harmful foreign particles, bacteria, or dead/dying cells, clearing them from the body. a copolymer approved by the US Food and Drug Administration for therapeutic devices due to its biodegradability and biocompatibility. a polymer with repeating units comprising an amine group and two carbon aliphatic CH2CH2 spacers; can be used as an adjuvant due to its ability to elicit a strong immune response. a preventative vaccine that involves the introduction of antigens into the body with the intention of creating antibodies for those antigens, such that the individual becomes immune to the associated illness. a process used to evaluate and control the quality of a pharmaceutical product, and to review its risks throughout the life cycle of the product; performed to ensure that the benefits outweigh the risks, and that the end user is not harmed in any way. an important type of lymphocyte (white blood cell) that has a key role in the adaptive immune response. a vaccine that involves the introduction of antigens into the body after the occurrence of an infection or disease to force the immune system to generate antibodies against those antigens, thereby curing the individual of the associated illness. a class of pattern recognition receptors that cause an immune response by recognizing conserved molecular patterns for early immune recognition of a pathogen.