Correlation Between Cryogenic Parameters and Physico-Chemical Properties of Porous Gelatin Cryogels

Abstract

In the present work, we have performed an in-depth physico-chemical and bio-physical evaluation of a series of previously described porous gelatin scaffolds (S. VanVlierberghe, V. Cnudde, P. Dubruel, B. Masschaele, A. Cosijns, I. DePaepe, P.J.S. Jacobs, L. VanHoorebeke, J.P. Remon and E. Schacht, Biomacromolecules 8, 331 (2007)). All scaffolds were prepared by a cryogenic treatment and subsequent freeze-drying. Three types of scaffolds were prepared by using different gelatin concentrations and cooling protocols. Type-I hydrogels were composed of cone-like pores with decreasing diameter from top (330 microm) to bottom (20-30 microm). Type-II and type-III scaffolds contained spherical pores with an average diameter of 135 (type II) and 65 microm (type III), respectively. The physico-chemical and bio-physical properties studied include the water uptake capacity and kinetics, the mechanical properties and the enzyme-mediated degradation. We can conclude that the pore geometry affects the water uptake capacity, the mechanical properties and the degradation profile of the hydrogels. Type-I hydrogels possess the highest water uptake, the lowest compression modulus and the fastest enzyme mediated degradation, indicating a clear effect of the pore morphology (elongated channels for type I versus spherical pores for types II and III) on the physico-chemical and bio-physical properties of the materials. In contrast to the effect of the pore geometry (channel-like versus spherical), the pore size does not significantly affect the water uptake, the mechanical properties and the enzyme mediated degradation in the investigated pore size range (65-135 microm). To the best of our knowledge, this is the first report in which the effects of a cryogenic treatment on the hydrogel network properties are investigated in such detail.

Gelatin-based hydrogels for biomedical applications

“…Methacrylamide-modified gelatin possesses both properties natural and synthetic gelatins having cell adhesion sites and tunable mechanical properties. [11,58,59] Ovsianikov et al [28] fabricated 3D CAD scaffolds for tissue engineering applications from methacrylamide-modified gelatin by using 2PP. The biocompatible photoinitiator Irgacure 2959 was employed for crosslinking the scaffolds.…”

Collagen- vs. Gelatine-Based Biomaterials and Their Biocompatibility: Review and Perspectives

“…Cross-linking of gelatine by UV-irradiation method involve premodification of gelatine amino groups (from Lys and Hyl side chains) (Dubruel et al, 2007), commonly by metacrilyc-anhydride ( Fig. 13) (Vlierberhe et al, 2009). In subsequent step, water-soluble gelatine-methacrylamide can be cross-linked not only by UV treatment, but, also by a number of suitable polymerization processes, such as redox, thermal, -irradiation or e-beam curing (Van Den Bulcke et al, 2000).…”

Novel gelatin–PHEMA porous scaffolds for tissue engineering applications

“…Methacrylamidemodified gelatin (MAG) has been recently developed and investigated for tissue regeneration purposes including wound treatment and attachment and growth of a wide variety of human cells. [11][12][13][14][15][16][17] This material is obtained through the direct reaction of primary amines from gelatin and methacrylic anhydride 14 and it can present various substitution degrees (DS). MAG's main advantage when compared to unmodified gelatin consists of the possibility of chemical crosslinking by the photoinitiated polymerization of C]C bonds.…”

“…Van Vlierberghe was the first to establish a cryogenic treatment followed by freeze-drying in order to generate porous MAG hydrogels with controlled properties. 15,16 It was shown that the cryogenic parameters combined with the MAG concentration applied influence the morphology and the Fig. 11 Visualization of human foreskin fibroblasts after cell seeding.…”