Semi-Interpenetrating Network (SIPN) Co-Electrospun Gelatin/Insulin Fiber Formulation for Transbuccal Insulin Delivery


Purpose: This work was aimed at developing a semi-interpenetrating network (sIPN) co-electrospun gelatin/insulin fiber scaffold (GIF) formulation for transbuccal insulin delivery. Methods: Gelatin was electrospun into fibers and converted into an sIPN following eosin Y-initiated polymerization of polyethylene glycol diacrylate (PEG-DA). The cytocompatibility, degradation rate and mechanical properties were examined in the resulting sIPNs with various ratios of PEG-DA to eosin Y to find a suitable formulation for transbuccal drug delivery. Insulin was co-electrospun with gelatin into fibers and converted into an sIPN-GIF using this suitable formulation. The in vitro release kinetics of insulin was evaluated using ELISA. The bioactivity of released insulin was analyzed in 3T3-L1 preadipocytes using Western blotting and Oil Red O staining. The transbuccal permeability of released insulin was determined using an in vitro porcine oral mucosa model. Results: The sIPN-GF formulation of GF cross-linked by PEG-DA (1% w/v) with eosin Y (5% v/v) possessed no cytotoxic effect, a moderate degradation rate with degradation half-life of 49 min, and a significant enhancement in mechanical properties. This formulation was used to fabricate sIPN-GIF. Insulin release was extended up to 4 h by sIPN-GIF. The released insulin successfully triggered intracellular AKT phosphorylation and induced adipocyte differentiation in 3T3-L1 preadipocytes. The transbuccal permeability of released insulin was determined on the order of 10-7 cm/s. Conclusions: Insulin can be fabricated into an sIPN-GIF formulation following co-electrospinning and cross-linking without losing bioactivity. It proved the potential of this new formulation for transbuccal insulin delivery.


Chemical and Biochemical Engineering

Keywords and Phrases

electrospun gelatin fiber; insulin; semi-interpenetrating network; transbuccal delivery

International Standard Serial Number (ISSN)

0724-8741; 1573-904X

Document Type

Article - Journal

Document Version


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© 2015 Springer New York LLC, All rights reserved.

Publication Date

01 Jan 2015

PubMed ID