Linkam temperature-controlled microscope stages used for studies on freeze-drying of biomaterials
The technique could be used to engineer living tissues for cancer treatment and cell-based medicine.
|Professor Xiaoming “Shawn” He (right) with two of his students, Samantha Stewart (left) and Yuntian Zhang (centre), next to the Linkam cryomicroscopy system. (Image: Linkham)|
Xiaoming He, a professor in the Fischell Department of Bioengineering at the University of Maryland, leads a research group that is focused on developing multiscale biomaterials to engineer living cells and tissues for cancer treatment and cell-based medicine. His base is the Multiscale Biomaterials Engineering Laboratory, which is dedicated to research and education on developing multiscale (nano, micro and macro) complex biomaterials and devices to either encapsulate and deliver small molecules, genes, peptides/proteins, cells, and tissues, or to engineer 3D biomimetic systems in vitro.
The ultimate goal of the latter project is improving the safety and efficacy of cancer treatment, tissue regeneration, and assisted reproduction.
One of the important fields in this work is the studdy of freeze drying (lyophilization). Professor He's group studies ice formation during cooling and freezing biological samples to minimize the damage to biological cells during cooling and freeze-drying biological samples for banking at both cryogenic and ambient temperatures.
For his freeze-drying studies, Professor He uses temperature-controlled microscope stages from Linkham Scientific (Tadworth, UK), which can be controlled to teperatures of from as low as -196 °C to as high as 600 °C. He uses the Linkam FDCS196 stage, which has a range of -196 to 120°C, in his research to study ice formation. This stage is widely used in lyophilization laboratories across the world. It combines a cryo stage with light microscopy techniques to determine collapse and eutectic temperatures and investigate the freeze-dried structure of complex samples.
Professor He has published widely. These include a paper which describes new ways of cryopreservation of stem cells.1 This is important to help meet the ever-increasing demands of cell-based medicine. The role of the Linkam stage was to study the inhibition of devitrification and intracellular ice formation. A second paper looks at ways of stopping cell injury that may occur in the cooling and warming processes.2 Here, the FDCS stage was used to mimic the ice seeding process and checking cell viability in situ.
For more info on Linkham's stages, see http://www.linkam.co.uk/temperature-controlled-stages.
1. Haishui Huang et al., "Alginate Hydrogel Microencapsulation Inhibits Devitrification and Enables Large-Volume Low-CPA Cell Vitrification," Adv. Funct. Mater. 2015, 25, 6839–6850; doi: 10.1002/adfm.201503047
2. Haishui Huang et al., "Predehydration and Ice Seeding in the Presence of Trehalose Enable Cell Cryopreservation," ACS Biomater. Sci. Eng. 2017, 3, 1758−1768; doi: 10.1021/acsbiomaterials.7b00201