Combined Silk Fibroin Microneedles for Insulin Delivery

Abstract

To reduce the pain caused by subcutaneous injections, microneedle patches as the new transdermal drug delivery method are gaining increased attention. In this study, we fabricated a composite insulin-loaded microneedle patch. Silk fibroin, a natural polymer material, was used as the raw material. The tip of the microneedle had good dissolving property and was able to dissolve rapidly to promote the release of insulin. The pedestal had the property of swelling without dissolving and was carrying insulin as a drug store. The insulin carried by the pedestal could release continuously through the micropore channels created by the microneedles. This kind of microneedle could achieve a sustained release effect. It was observed that the insulin had good storage stability in this kind of microneedle, and it maintained more than 90% of its biological activity after 30 days. The results of transdermal delivery to diabetic rats showed that the microneedle patches displayed an apparent hypoglycemic effect and indicated a sustained release effect. These drug-loaded silk microneedle patches may act as potential delivery systems for the treatment of diabetes.

Chemical, Thermal, Time, and Enzymatic Stability of Silk Materials with Silk I Structure

“…Jin H effectively controlled the β-sheet ratio to obtain a water-stable film containing Silk I crystals [ 17 ]. Zhu M et al used combined Silk I microneedles for drug delivery of insulin delivery [ 18 ]. Previous studies showed that Silk I-based materials had a metastable structure with poor stability and short storage time.…”

Recent developments in sustainably sourced protein-based biomaterials

“…Subcutaneous injections of silk fibroin hydrogels with encapsulated insulin enables sustained release of insulin for blood glucose control in diabetic rats [ 115 ]. Similarly, silk fibroin microneedle patches offer a sustained release of insulin via transdermal delivery, removing the need for traditional injections which require high patient compliance and careful management of injection sites to protect tissue integrity [ 116 ].…”

Translation of Polymeric Microneedles for Treatment of Human Diseases: Recent Trends, Progress, and Challenges

“…PDMS micro-molds have been produced, and a vacuum-based process for filling the forms with polylactic acid, polyglycolic acid, and their polymers was designed for replicating Microfabricated Master Structures [ 388 ]. The mechanical testing of the resulting needles measured the force that split the needles during axial loading and showed that this failed strength increased with the material and needle foundation diameter and decreased with the needle length [ 389 ]. The failure forces were normally much greater than the forces needed to inject MN into the skin, suggesting the mechanical properties of biodegradable polymers for MN were adequate [ 389 ].…”

“…The mechanical testing of the resulting needles measured the force that split the needles during axial loading and showed that this failed strength increased with the material and needle foundation diameter and decreased with the needle length [ 389 ]. The failure forces were normally much greater than the forces needed to inject MN into the skin, suggesting the mechanical properties of biodegradable polymers for MN were adequate [ 389 ]. Finally, the ranges of polymer MNs revealed that the permeability of human skin cadaver was improved by up to three orders of magnitude to a low-molecular tracer, a calcein, and a macromolecular, bovine serum Albumin [ 354 ].…”