The use of pH-responsive polymeric micelles is a promising approach to afford the targeted, pH-mediated delivery of hydrophobic drugs within the low-pH tumour milieu and intracellular organelles of cancer cells. However, even for a common pH-responsive polymeric micelle system—e.g., those utilising poly(ethylene glycol)-b-poly(2-vinylpyridine) (PEG-b-PVP) diblock copolymers—there is a lack of available data describing the compatibility of hydrophobic drugs, as well as the relationships between copolymer microstructure and drug compatibility. Furthermore, synthesis of the constituent pH-responsive copolymers generally requires complex temperature control or degassing procedures that limit their accessibility. Herein we report the facile synthesis of a series of diblock copolymers via visible-light-mediated photocontrolled reversible addition-fragmentation chain-transfer polymerisation, with a constant PEG block length (90 repeat units (RUs)) and varying PVP block lengths (46–235 RUs). All copolymers exhibited narrow dispersity values (Đ ≤ 1.23) and formed polymeric micelles with low polydispersity index (PDI) values (typically <0.20) at physiological pH (7.4), within a suitable size range for passive tumour targeting (<130 nm). The encapsulation and release of three hydrophobic drugs (cyclin-dependent kinase inhibitor (CDKI)-73, gossypol, and doxorubicin) were investigated in vitro at pH 7.4–4.5 to simulate drug release within the tumour milieu and cancer cell endosome. Marked differences in drug encapsulation and release were observed when the PVP block length was increased from 86 to 235 RUs. With a PVP block length of 235 RUs, the micelles exhibited differing encapsulation and release properties for each drug. Minimal release was observed for doxorubicin (10%, pH 4.5) and CDKI-73 exhibited moderate release (77%, pH 4.5), whereas gossypol exhibited the best combination of encapsulation efficiency (83%) and release (91% pH 4.5) overall. These data demonstrate the drug selectivity of the PVP core, where both the block molecular weight and hydrophobicity of the core (and accordingly the hydrophobicity of the drug) have a significant effect on drug encapsulation and release. These systems remain a promising means of achieving targeted, pH-responsive drug delivery—albeit for select, compatible hydrophobic drugs—which warrants their further investigation to develop and evaluate clinically relevant micelle systems.

No abstract

This paper introduces the significance of big data intelligent ideological and political education research in Colleges and universities in the new era, summarizes the research status of key technologies of Ideological and political education in Colleges and universities, and puts forward the concept of big data's intelligent ideological and political education classroom in Colleges and universities and key technologies of its model. Combined with the background of "a board of chess" epidemic prevention and control, taking Yunnan Normal University's education informatization and students' Ideological and political education work management as an example, this paper exemplifies "class suspension and keeping teaching" the working mechanism of big data's intelligent ideological and political classroom model in Colleges and universities and part of the front-end interface display are given, which provides reference for the research of big data's ideological and political education work and education information data center "a board of chess in the whole school".

No abstract

This note is based on 2‐constant Kubelka‐Munk theory and the first‐order approximat ion ofspectrum, presenting a method of linear programming to compute the recipes and to get the basic database quickly. A lot of experimental results in paints have shown that matching precision may be achieved by following this practice. © 1994 John Wiley & Sons. Inc.