Electrospinning Living Bacteria: A Review of Applications from Agriculture to Health Care

Abstract

Living bacteria are used in biotechnologies that lead to improvements in health care, agriculture, and energy. Encapsulating bacteria into flexible and modular electrospun polymer fabrics that maintain their viability will further enable their use. This review will first provide a brief overview of electrospinning before examining the impact of electrospinning parameters, such as precursor composition, applied voltage, and environment on the viability of encapsulated bacteria. Currently, the use of nanofiber scaffolds to deliver live probiotics into the gut is the most researched application space; however, several additional applications, including skin probiotics (wound bandages) and menstruation products have also been explored and will be discussed. The use of bacteria-loaded nanofibers as seed coatings that promote plant growth, for the remediation of contaminated wastewaters, and in energy-generating microbial fuel cells are also covered in this review. In summary, electrospinning is an effective method for encapsulating living microorganisms into dry polymer nanofibers. While these living composite scaffolds hold potential for use across many applications, before their use in commercial products can be realized, numerous challenges and further investigations remain.

Chitosan-Stabilized CuO Nanostructure-Functionalized UV-Crosslinked PVA/Chitosan Electrospun Membrane as Enhanced Wound Dressing

“…The nanofibrous structure increases skin growth. If incorporated within the fibers, a drug , or antibacterial NPs can be discharged into the curative wound in a regulated and homogeneous way. , These promising characteristics make electrospun membranes ideal platforms for developing new hybrid materials for rapid wound healing and antimicrobial effects. , …”

“…12,14 These promising characteristics make electrospun membranes ideal platforms for developing new hybrid materials for rapid wound healing and antimicrobial effects. 15,16 In this context, chitosan (CH)-based materials are suitable candidates as they are the second most available marine polysaccharides obtained from the exoskeleton of invertebrates. CH is a natural cationic polymer with outstanding biocompatibility, biodegradability, nontoxicity, and antimicrobial and cell adhesion properties that drew the attention of researchers in tissue-engineering and drug delivery applications.…”

Ethanol-free Cross-Linking of Alginate Nanofibers Enables Controlled Release into a Simulated Gastrointestinal Tract Model

“…Changes in the chemical and mass composition of the fibers before and after cross-linking were also investigated via Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and mass measurements. To demonstrate the potential applicability of cross-linked alginate-based nanofibers, green fluorescent beads were encapsulated within the fibers to model the encapsulation of bacteria because our ultimate goal is to deliver living probiotic bacteria to the gut to better understand their role in regulating bodily functions. , Here, we exposed the cargo-loaded cross-linked nanofibers to a simulated gastrointestinal tract (GIT) model to demonstrate a pH-dependent release of the cargo from the scaffolds.…”

Living Antimicrobial Wound Dressings: Using Probiotic-Loaded, Alginate Nanofibers for Protection against Methicillin-Resistant Staphylococcus aureus

“…5 In order to deploy the probiotic cells to the skin, encapsulation techniques can be used to form a physical barrier around the cells to both protect the probiotic cells from harmful agents and deliver them where they are needed. 6 Several techniques have been used to encapsulate bacteria cells, including extrusion, emulsion, spray drying, freeze-drying, and fluidized bed drying. 7 However, electrospinning uniquely encapsulates bacteria into polymer nanofiber scaffolds.…”

“…For example, Lactococcus lactis ( L. lactis ) produces antimicrobial agents that control the local populations of Streptococcus pneumoniae , Enterococcus faecalis , Clostridium difficile , and MRSA . In order to deploy the probiotic cells to the skin, encapsulation techniques can be used to form a physical barrier around the cells to both protect the probiotic cells from harmful agents and deliver them where they are needed …”