Air-Spun Silk-Based Micro-/Nanofibers and Thin Films for Drug Delivery.

Christopher R Gough,Xiao Hu

doi:10.3390/ijms22179588

Abstract

Micro-/nanofibers have shown high promise as drug delivery vehicles due to their high porosity and surface-area-to-volume ratio. The current study utilizes air-spraying, a novel fiber fabrication technique, to create silk micro-/nanofibers without the need for a high voltage power source. Air-spraying was used to create silk fibrous mats embedded with several model drugs with high efficiency. In order to compare the effect of biomaterial geometry on the release of the model drugs, silk films were also created and characterized. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and a drug release study were performed on both fiber and film samples to study how the model drugs interact with the protein structure. FTIR analysis showed that while drugs could interact with the protein structure of porous silk fibers, they could not interact with the flat geometry of silk films. As a result, fibers could protect select model drugs from thermal degradation and slow their release from the fiber network with more control than the silk films. A trend was also revealed where hydrophobic drugs were better protected and had a slower release than hydrophilic drugs. The results suggest that the physical and chemical properties of drugs and protein-based biomaterials are important for creating drug delivery vehicles with tailored release profiles and that fibers provide better tunability than films do.

Highlights

Protein-based drug delivery vehicles are an emerging field aiming to fix many of the problems with current drug delivery methods [1]
The results of this study indicate that diffusion mechanisms alone do not dictate drug release; when designing a drug delivery vehicle, especially a protein-based biomaterial, biophysical and biochemical interactions are important
Analysis showed that the porous 1D geometry of fibers provided a better network for the model drugs to interact with the protein structure of silk in order to change the release speed of the model drugs in an aqueous solution

Summary

Introduction

Protein-based drug delivery vehicles are an emerging field aiming to fix many of the problems with current drug delivery methods [1]. Often, these vehicles take the form of micro-/nanofibers [1,2,3,4,5,6,7,8] or thin films [1,2,3,5,6,9]. The clinical use of submicrometer fibers is limited by a lack of quantitative data and a reliable large-scale production method [16]

Methods

Results

Discussion

Conclusion