Biomedical subjects

Hai-Bang Lee

Publications and source records attributed to Hai-Bang Lee.

2 recordsLinked to original sources

PubMed2004

Effect of acid-base interaction between silica and fragrant oil in the PCL/PEG microcapsules.

In this work, the biodegradable poly(epsilon-caprolactone) (PCL)/poly(ethylene glycol) (PEG) microcapsules were prepared in the presence of SiO(2) and fragrant oil using emulsion solvent evaporation method. And SiO(2) was chemically treated in 30 wt.% hydrochloric acid and sodium hydroxide. The effect of chemical treatment on SiO(2) surfaces was studied in terms of pH, acid-base value, and N(2)/77 K gas adsorption. Image analyzer and scanning electron microscope (SEM) were used to observe the shape and surface change of the prepared microcapsules. And the variation of surface free energy of microcapsules was characterized by contact angles. The results showed that the average diameter, surface free energy, and fragrant oil release rate of microcapsules were increased with increasing the PEG ratio. Also, it was found that in the case of basic treated SiO(2), the fragrant oil adsorption capacity and release rate were decreased due to the decrease of specific surface area or the increase of acid-base interactions between basic SiO(2) and acidic fragrant oil.

Adsorption↗

PubMed2002

Glucose binding to molecularly imprinted polymers.

The main goal of this study was to prepare molecularly imprinted polymers (MIPs) with glucose recognition sites and to evaluate their glucose-binding properties for potential applications in glucose sensing and self-regulating insulin delivery devices. To mimic glucose-binding sites of natural proteins, monomers possessing functional groups similar to amino acids were used. Vinyl acetic acid (VAA), acrylamide (AAm), 4-pentenoic acid (PA), and allyl benzene (AB) were copolymerized with a cross-linking agent (N,N'-methylenebisacrylamide, BIS) in the presence of glucose as a template. The binding affinity of glucose to MIPs was examined by using an equilibrium dialysis technique. The dissociation constants of the MIPs were determined by Scatchard analysis. MIPs showed glucose-binding affinity, while polymers synthesized in the absence of glucose template did not show a glucose-binding property. MIPs composed of VAA, AAm, PA, and AB at optimized mole ratios of monomers and cross-linker showed the highest glucose-binding affinity, KD = 1.66 mM, which is comparable to that of a well-known glucose binding protein, concanavalin A (KD = 1.84 mM). The affinity between monomer and glucose was in the order VAA > AAm > AB > PA.

Binding Sites↗