RESUMEN

Natural biopolymers have a rich history, with many uses across the fields of healthcare and medicine, including formulations for wound dressings, surgical implants, tissue culture substrates, and drug delivery vehicles. Yet, synthetic-based materials have been more successful in translation due to precise control and regulation achievable during manufacturing. However, there is a renewed interest in natural biopolymers, which offer a diverse landscape of architecture, sustainable sourcing, functional groups, and properties that synthetic counterparts cannot fully replicate as processing and sourcing of these materials has improved. Proteins and polysaccharides derived from various sources (crustaceans, plants, insects, etc.) are highlighted in this review. We discuss the common types of polysaccharide and protein biopolymers used in healthcare and medicine, highlighting methods and strategies to alter structures and intra- and interchain interactions to engineer specific functions, products, or materials. We focus on biopolymers obtained from natural, nonmammalian sources, including silk fibroins, alginates, chitosans, chitins, mucins, keratins, and resilins, while discussing strategies to improve upon their innate properties and sourcing standardization to expand their clinical uses and relevance. Emphasis will be placed on methods that preserve the structural integrity and native biological functions of the biopolymers and their makers. We will conclude by discussing the untapped potential of new technologies to manipulate native biopolymers while controlling their secondary and tertiary structures, offering a perspective on advancing biopolymer utility in novel applications within biomedical engineering, advanced manufacturing, and tissue engineering.

RESUMEN

Silk fibers are produced by a wide variety of insects. The silkworm Bombyx mori (Bombyx) was domesticated because the physical properties of its silk fibers were amenable to the production of fine textiles. Subsequently, engineers have regenerated silk fibroin to form biomaterials. The monocular focus on Bombyx silk has underutilized the expanse of diverse silk proteins produced by more than 100,000 other arthropods. This vast array of silk fibers could be utilized for biomedical engineering challenges if sufficient rearing and purification processes are developed. Herein, we show that the moth, Plodia interpunctella (Plodia), represents an alternative silk source that is easily reared in highly regulated culture environments allowing for greater consistency in the silk produced. We controlled the temperature, resource availability (larvae/gram diet), and population density (larvae/mL) with the goal of increasing silk fiber production and improving homogeneity in Plodia silk proteins. We determined that higher temperatures accelerated insect growth and reduced life cycle length. Furthermore, we established initial protocols for the production of Plodia silk with optimal silk production occurring at 24 °C, with a resource availability of 10 larvae/gram and a population density of 0.72 larvae/mL. Population density was shown to be the most prominent driving force of Plodia silk mat formation among the three parameters assessed. Future work will need to link gene expression, protein production and purification, and resulting mechanical properties as a function of environmental cues to further transition Plodia silk into regenerated silk fibroin biomaterials.

Asunto(s)

Bombyx , Fibroínas , Animales , Seda/metabolismo , Bombyx/genética , Materiales Biocompatibles , Fenómenos Mecánicos

RESUMEN

The fields of drug and gene delivery have been revolutionized by the discovery and characterization of polymer-based materials. Polymeric nanomaterials have emerged as a strategy for targeted delivery because of features such as their impressive biocompatibility and improved availability. Use of naturally derived polymers in these nanomaterials is advantageous due to their biodegradability and bioresorption. Natural biopolymer-based particles composed of silk fibroins and other silk fiber-inspired proteins have been the focus of research in drug delivery systems due to their simple synthesis, tunable characteristics, and ability to respond to stimuli. Several silk and silk-inspired polymers contain a high proportion of reactive side groups, allowing for functionalization and addition of targeting moieties. In this review, we discuss the main classes of silk and silk-inspired polymers that are being used in the creation of nanomaterials. We also focus on the fabrication techniques used in generating a tunable design space of silk-based polymeric nanomaterials and detail how that translates into use for drug delivery to several distinct microenvironments.