Speaker
Description
Sustained release of encapsulated drug carriers through biodegradation of the host microgel matrices has been attracting significant interests in the field of pharmaceutical sciences, due to its bioindustrial relevance and high-precision controllability [1-2]. For fabricating such microhybrids, biopolymer microgels have been widely adopted as a degradable platform by enzymatic activities [3]. In particular, the use of chip-based microsystems for monitoring temporal behaviours of microscale gels has been extensively studied [4]. In this presentation, we show time-dependent degradation characteristics of silica particle-laden microgels and its correlated release kinetics of particles, by tuning the gel elasticity. In order to implement soft gel matrices, the biodegradable microgel spheres are fabricated based on the 3D network of gelatine chains, which are covalently crosslinked by a naturally derived crosslinker, genipin [5]. Within the gelatine network, fluorescent silica particles are embedded using physical entrapment methods. The gel matrix is designed to have strong autofluorescence, and the microgel elasticity is controlled by varying crosslinking degree. Enzymatic surface erosion of microgel matrices is induced by the addition of low-concentration of collagenase and subsequent incubation at 37°C. 3D printing technology is employed for fabricating microfluidic chips that are utilised for the synthesis and monitoring processes of microgels [6]. The microgel size change and release amount of particles are monitored in situ using high-resolution time-lapse fluorescence microscopy, coupled with advanced image processing techniques.
References
[1] M. Karg, A. Pich, T. Hellweg, T. Hoare, L. A. Lyon, J. J. Crassous, D. Suzuki, R. A. Gumerov, S. Schneider, I. I. Potemkin, W. Richtering: Nanogels and microgels: from model colloids to applications, recent developments, and future trends. Langmuir 35, 6231-6255 (2019);
[2] H. Bysell, R. Månsson, M. Malmsten: Microgels and microcapsules in peptide and protein drug delivery. Adv. Drug Deliv. Rev. 63, 1172-1185 (2011);
[3] R. Windenbring, G. Frenning, M. Malmsten: Chain and pore-blocking effects on matrix degradation in protein-loaded microgels. Biomacromolecules 15, 3671-3678 (2014);
[4] X. Zhang, L. Li, C. Luo: Gel integration for microfluidic applications. Lab Chip 16, 1757-1776 (2016);
[5] B. Sung, C. Kim, M-H. Kim: Biodegradable colloidal microgels with tunable thermosensitive volume phase transitions for controllable drug delivery. J. Colloid Interface Sci. 450, 26-33 (2015);
[6] J.S. O'Connor, H. Kim, E. Gwag, L. Abelmann, B. Sung, A. Manz: 3D printing for microgel-based liver cell encapsulation. Proc. 34th IEEE MEMS, Jan. 2021, pp. 1023-1026 (2021)
| Keywords | Gelatine, Hydrogel, Microfluidics, Biodegradation, Collagenase |
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