Insulin-Loaded Silk Fibroin Microneedles as Sustained Release System.

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Nanotechnology

Background:

• Silk fibroin is a biocompatible and biodegradable material widely used in biomedical applications.
• Microneedles represent a promising approach for efficient transdermal drug delivery.
• Modifying silk fibroin's crystal structure can enhance its properties for drug delivery.

Purpose of the Study:

• To develop and characterize silk fibroin microneedles incorporating proline for transdermal insulin delivery.
• To investigate the effect of proline on the structural and mechanical properties of silk fibroin.
• To evaluate the efficacy and release kinetics of insulin from the fabricated microneedles.

Main Methods:

• Silk fibroin microneedles were fabricated with the addition of proline.
• Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were used to analyze structural changes.
• Mechanical strength was assessed to ensure skin penetration capability.
• In vitro drug release studies were conducted using insulin as a model drug.

Main Results:

• Proline treatment induced a structural transformation of silk fibroin from random coils to beta-sheets, forming a Silk I type structure.
• The fibroin/proline microneedles exhibited non-toxicity, biodegradability, and sufficient mechanical strength for skin penetration.
• In vitro release experiments demonstrated a sustained release of insulin over 60 hours.
• Proline showed good compatibility with silk fibroin.

Conclusions:

• Silk fibroin/proline microneedles are effective, non-toxic, and biodegradable carriers for transdermal insulin delivery.
• The structural modifications induced by proline enhance the microneedle properties for sustained drug release.
• This novel microneedle system offers a potentially painless and effective alternative for insulin administration in diabetic patients.