Functional and antibacterial characterization of electrospun nanofiber membranes made of chitosan and polyvinyl alcohol

2024-3-9

Hello, my name is Tsumugi, a researcher. I’m here to introduce a piece of literature.

Tsumugi
She is a second-year researcher in the Nanofiber Division of MECC.
Her hobbies include reading science magazines and the latest
research papers, as well as karate. Her special skill is speaking Chinese.

Objective

To develop nanomaterials with enhanced functional properties aimed at medical applications.
To mix chitosan with other polymers and adjuvants (PVA, CMC, pectin) and use electrospinning technology to create nanofibers.
To increase mechanical and structural properties through the combination of chitosan, PVA, pectin, and carboxymethyl cellulose (CMC).

Notes

Carboxymethyl Cellulose (CMC): A derivative of cellulose, CMC is a water-soluble polymer that functions by dissolving in water to produce viscosity. It serves as a thickening agent or an emulsion stabilizer used in food applications, medicated toothpaste & poultice, cosmetics, laundry detergents, printing paste, building materials, as an adhesive, in aquaculture feed & pet food as a binder, and in the manufacturing process of lithium-ion batteries, as per the CMC Industry Association (cmc-kogyokai.org).
Pectin: A natural polysaccharide found in various vegetables and fruits, pectin plays a role in binding plant cells together. The pectin used as a food additive is mainly extracted from apples and citrus fruits (lemons & limes), and it is used as a gelling agent, stabilizer, and thickener in jams, fruit sauces, and acidic dairy drinks. Source: https://www.tatourui.com/about/type/05_pectin.html
Chitosan: Noted for its biocompatibility, biodegradability, and antimicrobial activity, chitosan is non-toxic and enhances the wound healing process. However, spinning chitosan alone presents significant challenges, and it is commonly used mixed with various polymers and adjuvants.
PVA: Polyvinyl alcohol (PVA) possesses water solubility, biodegradability, biocompatibility, and chemical stability.

Experimental Procedure

Preparation of Polymer Solutions for Electrospinning:

Chitosan-acetic acid solution
PVA-water solution
CMC-water solution
Pectin-water solution

From these polymer solutions, four mixed solutions were prepared:

PVA
Chitosan/PVA
Chitosan/PVA/Pectin
Chitosan/PVA/CMC

Electrospinning conditions were set at a voltage of 20kV, nozzle-to-collector distance of 120mm, feed rate of 0.02ml/h, and an inner needle diameter of 806.046μm.

The produced nanofiber membranes were analyzed and evaluated using various methods.

Summary By using electrospinning technology with a mixture of chitosan, PVA, pectin, and CMC, nanofiber membranes were successfully created. The addition of adjuvant agents improved desirable properties for membranes intended to absorb exudate from the skin surface, such as swelling, vapor transmission, and biodegradability. The addition of adjuvant agents made the nanofibers tougher, stronger, and more flexible. The nanofiber membranes demonstrated effective contact inhibition against Staphylococcus aureus. These nanofiber membranes are excellent materials for treating skin diseases.

Reflections

We always use PEO for spinning chitosan in our company, but I am interested in trying spinning with PVA.
Conversely, why was PVA used? Can the same effects be expected with PEO?
Chitosan inhibits the activity of Staphylococcus aureus. I knew chitosan was used in regenerative medicine, but I was unaware of its antimicrobial properties. The antibacterial effect is enhanced when the degree of acetylation of chitosan exceeds 90%, which is also friendly for ulcer treatment. Chitosan is too capable.
The addition of adjuvants (Pectin, CMC) made the nanofibers stronger and more flexible. Combining different materials brings about new properties.

The conductivity of PVA is high, but it seems that adding chitosan reduces the conductivity! I would like to actually experiment with this!

References
https://www.sciencedirect.com/science/article/pii/S2211715624000109