Blending chitosan with polycaprolactone: effects on physicochemical and antibacterial properties

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Surface Science

Background:

• Chitosan is a valuable polysaccharide for biomedical uses, but its properties can be improved by blending.
• The impact of blending chitosan with poly(epsilon-caprolactone) (PCL) on its antibacterial and mechanical characteristics is not fully understood.

Purpose of the Study:

• To assess the antibacterial activity and physicochemical changes of chitosan when blended with PCL.
• To investigate the mechanical, degradation, and surface properties of chitosan/PCL membranes.

Main Methods:

• Chitosan and PCL were blended in various ratios and formed into membranes.
• Mechanical testing under wet conditions, antibacterial assays, 4-week degradation studies, FTIR, WAXD, DMTA, and AFM were performed.

Main Results:

• Chitosan/PCL membranes sustained loads up to 1 MPa without fracture.
• PCL addition reduced chitosan's antibacterial efficacy against tested bacteria.
• Degradation studies showed initial weight loss of chitosan, with no significant changes later.
• FTIR and WAXD confirmed no chemical bonding or crystal structure changes.
• DMTA indicated suppressed PCL crystallinity and increased storage modulus with chitosan addition.
• AFM revealed increased surface roughness in blends compared to pure chitosan.

Conclusions:

• Blending chitosan with PCL compromises its inherent antibacterial activity.
• The observed changes in biological and antibacterial properties are likely due to altered surface topography.
• Chitosan/PCL blends offer potential for applications requiring modified surface characteristics and mechanical integrity.