title: Tailoring the properties of gelatin films for drug delivery applications: influence of the chemical cross-linking method.
abstract: Two types of chemically cross-linked gelatin films were prepared and characterized. The first type of films was cross-linked with 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide hydrochloride (EDC) under heterogeneous conditions and are named Gel-E. In the second type of films, gelatin was previously functionalized with methacrylamide side groups by the reaction with methacrylic anhydride and for that is named Gel-MA. The modified gelatin was subsequently cross-linked by a photoinitiated radical polymerization. These films were characterized relatively to their degree of cross-linking, buffer uptake capacity, resistance to hydrolytic and proteolytic degradation, and mechanical and thermal properties. Results show that the employed cross-linking method, together with the degree cross-linking, dictate the final properties of the films. Gel-E films have significant lower buffer uptake capacities and higher resistance to collagenase digestion when compared to Gel-MA films. Additionally, Gel-E films exhibit higher values of stress at break and lower strains at break. Moreover, the films properties could be modified by varying the extent of the chemical cross-linking, which in turn could be controlled by varying the concentration of EDC, for the first type of films (Gel-E), or by using gelatins with different degrees of functionalization, in the case of the second type of films (Gel-MA).
authors: CIEPQPF, Chemical Engineering Department, University of Coimbra, Polo II, 3030-290 Coimbra, Portugal. Electronic address: patricia@eq.uc.pt.
authors: P
authors: P
authors: Coimbra
authors: CIEPQPF, Chemical Engineering Department, University of Coimbra, Polo II, 3030-290 Coimbra, Portugal.
authors: M H
authors: MH
authors: Gil
authors: CIEPQPF, Chemical Engineering Department, University of Coimbra, Polo II, 3030-290 Coimbra, Portugal.
authors: M
authors: M
authors: Figueiredo
mesh_terms: D001672:Biocompatible Materials; D002021:Buffers; D003432:Cross-Linking Reagents; D016503:Drug Delivery Systems; D005780:Gelatin / Q000138:chemical synthesis / Q000737:chemistry*; D006868:Hydrolysis; D055595:Mechanical Phenomena; D058105:Polymerization; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D002021:Buffers; D003432:Cross-Linking Reagents; C015233:gelatin film; D005780:Gelatin
keywords: Carbodiimide; Chemical cross-linking; Gelatin films; Methacrylic anhydride