Exploring the landscape of Lipid Nanoparticles (LNPs): A comprehensive review of LNPs types and biological sources of lipids

Abstract

Lipid nanoparticles (LNPs) have emerged as promising carriers for delivering therapeutic agents, including mRNA-based immunotherapies, in various biomedical applications. The use of LNPs allows for efficient delivery of drugs, resulting in enhanced targeted delivery to specific tissues or cells. These LNPs can be categorized into several types, including liposomes, solid lipid nanoparticles, nanostructured lipid carriers, and lipid-polymer hybrid nanoparticles. The preparation of LNPs involves the manipulation of their structural, dimensional, compositional, and physical characteristics via the use of different methods in the industry. Lipids used to construct LNPs can also be derived from various biological sources, such as natural lipids extracted from plants, animals, or microorganisms. This review dives into the different types of LNPs and their preparation methods. More importantly, it discusses all possible biological sources that are known to supply lipids for the creation of LNPs. Natural lipid reservoirs have surfaced as promising sources for generating LNPs. The use of LNPs in drug delivery is expected to increase significantly in the coming years. Herein, we suggest some environmentally friendly and biocompatible sources that can produce lipids for future LNPs production.

Keywords: Biological sources; Biotechnology; Drug delivery; Lipid nanoparticles; Lipids.

Graphical abstract

Fig. 1

Different types of nanoparticles categorized by a production method. Nanoparticles are categorized based on the most common method of production used in the literature, and more than one production method may be applied to produce the same type of nanoparticles. The arrows indicate that all types of nanoparticles can be produced (formulated) functionalized (modification of the surface of the particle) using chemical methods. This figure visualizes the nanoparticle types and its production methods.

Fig. 2

A simple visual aid to view Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid Carriers (NLC) structure. LNPs can be categorized based on the type of lipids used and their configuration. For example, by integrating liquid lipids, as demonstrated in NLS, during the formulation the structure changes which in turn affects it's characteristics and type.

Fig. 3

Different preparation methods of LNPs formation. Methods are usually classified based on the energy input to form LNPs. These methods can be broadly divided into two categories: low and high energy. Low energy techniques rely on spontaneous self-assembly of lipids in solution. These methods require minimal external energy and are often favored for their simplicity and scalability. In contrast, high energy methods involve the application of significant mechanical energy to form LNPs. These techniques typically involve breaking down lipid aggregates or emulsions into nanoparticles by applying intense shear forces or sonic waves.

Fig. 4

Bio-sources of lipids that can be utilized in LNPs formation. Lipids can be extracted from various biological sources. Through our research, we categorize them to 5 main sources, with the term ‘derived’ used for the product of the source while the term ‘sourced’ is used to refer to the use of the organism itself. Those sourced from plants and derived from microorganisms, animal and animal derived, and lastly human sourced. The sources listed provide lipids that are most commonly used in the formation of LNPs.