Springlike nanohelical structures in chiral block copolymers.
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Crystallization↗
Biomedical subjects
Rong-Ming Ho
Publications and source records attributed to Rong-Ming Ho.
Three-dimensionally packed nanohelical phase in chiral block copolymers.
Chirality-driven microphase-separated morphology, poly(l-lactide) (PLLA) left-handed nanohelices hexagonally packed in PS matrix, was obtained from chiral diblock copolymers, poly(styrene)-b-poly(l-lactide). This is perhaps for the first time; the helical superstructures of chiral block copolymers were generated in the bulk and self-assembled to a two-dimensionally (2D) packed lattice. Now, the analyses of block copolymer thermodynamics should be complicated by the chiral entities of constituted components. Orderly packed nanohelical channels can be obtained after hydrolysis, and this provides new opportunities for block copolymer applications in the fields of nanosciences.
Journal Article↗
Novel method using a temperature-sensitive polymer (methylcellulose) to thermally gel aqueous alginate as a pH-sensitive hydrogel.
A novel method using a temperature-sensitive polymer (methylcellulose) to thermally gel aqueous alginate blended with distinct salts (CaCl2, Na2HPO4, or NaCl), as a pH-sensitive hydrogel was developed for protein drug delivery. It was noted that the salts blended in hydrogels may affect the structures of an entangled network of methylcellulose and alginate and have an effect on their swelling characteristics. The methylcellulose/alginate hydrogel blended with 0.7 M NaCl (with a gelation temperature of 32 degrees C) demonstrated excellent pH sensitivity and was selected for the study of release profiles of a model protein drug (bovine serum albumin, BSA). In the preparation of drug-loaded hydrogels, BSA was well-mixed to the dissolved aqueous methylcellulose/alginate blended with salts at 4 degrees C and then gelled by elevating the temperature to 37 degrees C. This drug-loading procedure in aqueous environment at low temperature may minimize degradation of the protein drug while achieving a high loading efficiency (95-98%). The amount of BSA released from test hydrogels was a function of the amount of alginate used in the hydrogels. The amount of BSA released at pH 1.2 from the test hydrogel with 2.5% alginate was relatively low (20%), while that released at pH 7.4 increased significantly (86%). In conclusion, the methylcellulose/alginate hydrogel blended with NaCl could be a suitable carrier for site-specific protein drug delivery in the intestine.
Alginates↗