Biomedical subjects

Tao He

Publications and source records attributed to Tao He.

57 records · Page 4Linked to original sources

PubMed2002

Enabling parallel protein analysis through mass spectrometry.

The targets of the majority of drugs on the market and in development are proteins, and the efficient analysis of these molecules is critical to defining targets for better therapeutic intervention. Mass spectrometry is currently the key technology for parallel protein analysis (also referred to as proteomics). In this review we will describe recent advances in mass spectrometry instrumentation, methods and applications that are likely to impact drug discovery.

Animals↗

PubMedDate not supplied

Layer-by-layer assembly to modify poly(l-lactic acid) surface toward improving its cytocompatibility to human endothelial cells.

A novel technique to introduce free amino groups onto polyester scaffolds via aminolyzing the ester groups with diamine has been developed recently. Positively charged chitosan was then deposited onto the aminolyzed poly(l-lactic acid) (PLLA) membrane surface in a layer-by-layer assembly manner using poly(styrene sulfonate, sodium salt) (PSS) as a negatively charged polyelectrolyte. The layer-by-layer deposition process of PSS and chitosan was monitored by UV-vis absorbance spectroscopy, energy transfer by fluorescence spectroscopy, and advancing contact angle measurements. The existed chitosan obviously improved the cytocompatibility of PLLA to human endothelial cells. The cell attachment, activity, and proliferation on the PLLA membranes assembled with three or five bilayers of PSS/chitosan with chitosan as the outermost layer were better than those with one bilayer of PSS/chitosan or the control PLLA. The cells also showed morphology of an elongated shape with abundant cytoplasm, and a confluent cell layer was reached after being cultured for 4 days. Measurement of von Willebrand factor secreted by these endothelial cells (ECs) verified the endothelial function. Hence, better ECs compatible PLLA were produced.

Cells, Cultured↗

PubMedDate not supplied

Immobilization of biomacromolecules onto aminolyzed poly(L-lactic acid) toward acceleration of endothelium regeneration.

By reaction of poly(L-lactic acid) (PLLA) membrane with 1,6-hexanediamine, free amino groups were introduced onto a PLLA surface, through which biocompatible macromolecules such as gelatin, chitosan, or collagen were covalently immobilized by employing glutaraldehyde as a coupling agent. The existence of free amino groups on the aminolyzed PLLA surface was verified quantitatively by the ninhydrin analysis method, which revealed that surface NH(2) density increased with 1,6-hexanediamine concentration or aminolyzing time. Scanning force microscopy measurements detected an increase in surface roughness after aminolysis. The culture of human umbilical vein endothelial cells (HUVECs) in vitro proved that the cell proliferation rate and cell activity of both aminolyzed and biomacromolecule-immobilized PLLAs were improved compared with control PLLA. Scanning electron microscopy observation showed more spreading and flat cell morphology after HUVECs were cultured for 4 days on either aminolyzed or biomacromolecule-immobilized PLLA membranes. Confluent cell layers were observed on the modified PLLA. Measurement of von Willebrand factor secreted by these HUVECs confirmed that endothelium function was maintained. Therefore, aminolysis and biomacromolecule immobilization are promising ways to accelerate endothelium regeneration, which is crucial for blood vessel tissue engineering.

Biocompatible Materials↗