Natural Polymers in Micro- and Nanoencapsulation for Therapeutic and Diagnostic Applications: Part I: Lipids and Fabrication Techniques

Abstract

Encapsulation, specifically microencapsulation is an old technology with increasing applications in pharmaceutical, agrochemical, environmental, food, and cosmetic spaces. In the past two decades, the advancements in the field of nanotechnology opened the door for applying the encapsulation technology at the nanoscale level. Nanoencapsulation is highly utilized in designing effective drug delivery systems (DDSs) due to the fact that delivery of the encapsulated therapeutic/diagnostic agents to various sites in the human body depends on the size of the nanoparticles. Compared to microencapsulation, nanoencapsulation has superior performance which can improve bioavailability, increase drug solubility, delay or control drug release and enhance active/passive targeting of bioactive agents to the sites of action. Encapsulation, either micro- or nanoencapsulation is employed for the conventional pharmaceuticals, biopharmaceuticals, biologics, or bioactive drugs from natural sources as well as for diagnostics such as biomarkers. The outcome of any encapsulation process depends on the technique employed and the encapsulating material. This chapter discusses in details (1) various physical, mechanical, thermal, chemical, and physicochemical encapsulation techniques, (2) types and classifications of natural polymers (polysaccharides, proteins, and lipids) as safer, biocompatible and biodegradable encapsulating materials, and (3) the recent advances in using lipids for therapeutic and diagnostic applications. Polysaccharides and proteins are covered in the second part of this chapter.

Micro- and Nanocarriers for Encapsulation of Biological Plant Protection Agents: A Systematic Literature Review

“…Natural polymers are macromolecules of varying molecular weight obtained from plants, animals, and microorganisms that are often selected due to their wide flexibility toward modification, biocompatibility, biodegradability, sustainability, and low toxicity. 8 Natural polymers such as polysaccharides, proteins, and lipids have been employed as encapsulation materials for hydrophilic or hydrophobic active ingredients which may be in different physical states for transport and delivery to specific sites.…”

“…This process of encapsulation can be applied in many instances, for example, in the immobilization of volatile compounds, peptides, enzymes, and microorganisms; protection and stabilization of BPPAs from environmental stress; safer handling of hazardous but useful materials; controlled release of active ingredients; taste, odor, and color masking; and site-specific delivery and solidification of liquid droplets. 8 In addition, encapsulation of active ingredients can address the challenges of conventional dosage forms through enhancement of stability, taste, bioavailability, and/or biodistribution.…”

Polysaccharide-based nanocomposites for biomedical applications: a critical review

“…One approach is to add 2D or 3D nanomaterials to the PSAs in order to make them strongly interacted and accelerate their shear thinning behavior. 226,227 As an instance, 2D nanosilicate reinforced kappa-carrageenan (kCA) hydrogel was prepared in order to give it shear thinning characteristics, higher mechanical stiffness, elastomeric properties, and physiological stability. Scientists utilized this new platform for the delivery of human mesenchymal stem cells and their analysis demonstrated the high cell viability (85% cell viability) (Fig.…”

Natural sources and encapsulating materials for probiotics delivery systems: Recent applications and challenges in functional food development

“…This also reduces the cost by minimizing the dependency on additional organic solvents. Another advanced extrusion technique is centrifugal extrusion which involves the application of concentric orifices at the outlet of the nozzle sprayer and hence producing the microcapsules of desired size ( 26 ).…”