Articles by Yongsan Li in JoVE
Preparation of Chitosan-based Injectable Hydrogels and Its Application in 3D Cell Culture Yongsan Li1, Yaling Zhang2, Yen Wei1, Lei Tao1 1The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, 2Institute of Chemical Materials, China Academy of Engineering Physics Here we describe a facile preparation of chitosan-based injectable hydrogels using dynamic imine chemistry. Methods to adjust the hydrogel’s mechanical strength and its application in 3D cell culture are presented.
Other articles by Yongsan Li on PubMed
Modulus-regulated 3D-cell Proliferation in an Injectable Self-healing Hydrogel Colloids and Surfaces. B, Biointerfaces. Jan, 2017 | Pubmed ID: 27756013 Cell therapy has attracted wide attention among researchers in biomaterial and medical areas. As a carrier, hydrogels that could keep high viability of the embedded cells have been developed. However, few researches were conducted on 3D cell proliferation, a key factor for cell therapy, especially after injection. In this study, we demonstrated for the first time the proliferation regulation of the 3D-embedded L929 cells in a modulus-tunable and injectable self-healing hydrogel before and after injection without adding specific growth factor. The cells showed a stiffness-dependent proliferation to grow faster in higher stiffness hydrogels. The proliferating rates of the encapsulated cells before and after injection were quantified, and the shearing force as a possible negative influence factor was discussed, suggesting the both internal property of the hydrogel and injection process are critical for further practical applications. Due to the high operability and good biocompatibility, this injectable self-healing hydrogel can be a promising carrier for cell therapy.
Adaptive Chitosan Hollow Microspheres As Efficient Drug Carrier Biomacromolecules. Jul, 2017 | Pubmed ID: 28558194 Smart drug carrier with function-oriented adaptations is highly desired due to its unique properties in medical applications. Herein, adaptive chitosan hollow microspheres (CHM) are fabricated by employing interfacial Schiff-base bonding reaction. Hydrophilic macromolecules of glycol chitosan are fixed at the oil/water interface through numerous hydrophobic small molecules of borneol 4-formylbenzoate, forming the CHM with a positively charged surface and lipophilic cavity. These CHM have an average size of 400-1000 nm after passing through the 0.22 μm apertures of filter paper. This phenomenon combined with SEM measurements demonstrates its remarkable shape-adaptive behavior. Furthermore, the CHM present a pH-dependence of structural stability. When pH value reduces from 7.06 to 5.01, the CHM begin to lose their integrity. All those characteristics make the CHM an intelligent drug carrier, especially for water-insoluble anticancer drugs, paclitaxel (PTX) in particular. Both cell uptake and cell cytotoxicity assays suggest that the PTX-loaded CHM are highly efficient on HepG2 and A549 cells. Therefore, rather than most of the traditional materials, these adaptive CHM show great potential as a novel drug carrier.