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As a new kind of functional material, micron-sized porous polymer microspheres are a hot research topic in the field of polymer materials. Poly(glycidyl methacrylate)microspheres have been widely used in many fields, such as immobilization of bioactive substances (enzymes, cells, proteins, antibodies, etc.). There are three main preparation methods of PGMA microspheres: suspension polymerization, the seed expansion method, and precipitation polymerization. By introducing different functional groups into microspheres, the hydrophobicity, solubility and biocompatibility of the microspheres were improved, and the microspheres with different characteristics could be applied as high performance chromatographic fillers and catalyst carriers and in biomedical and adsorbent fields. In this paper, the development history, preparation methods, functionalization and application of poly(GMA-co-EGDMA) composite microspheres are reviewed systematically and comprehensively. Finally, the existing application materials based on PGMA microspheres are summarized and analyzed, and the application prospect of poly(GMA-co-EGDMA) composite microspheres in the future is analyzed.

Hydrogels have a wide range of applications in the fields of biomedicine, flexible electronics, and bionics. In this study, injectable and self-healable hydrogels were first prepared based on a dynamic covalent C═C bond formed via the Knoevenagel condensation reaction between poly(ethylene glycol) dicyanoacetate and water-soluble poly(vanillin acrylate). Three kinds of catalysts (phosphate buffer, zeolitic imidazolate framework-8, and tertiary amine) were used in Knoevenagel condensation for preparing hydrogels. All hydrogels in this study could be formed in situ, and their gelation time ranged from seconds to minutes. The properties and application of hydrogels could be customized according to the type of catalyst employed. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) results indicated that all the components and hydrogels exhibited low toxicity, and the hydrogels could be used as 3D cell culture scaffolds. Because of the dynamic covalent C═C bond formed by Knoevenagel condensation, the resultant hydrogels were found to be dynamic and showed good self-healing properties. This work presents a new dynamic covalent chemistry for the preparation of self-healable materials.

The Michael addition and alkylation reaction of active methylene compounds (AMCs) with two active hydrogens had been investigated extensively in organic chemistry, while the polymerization of AMCs had few studies. Herein, we reported active methylene-based polyaddition and polyalkylation catalyzed via an organic superbase under ambient conditions. A model polymerization was first conducted between ethylene glycol diacrylate (EGDA) and methyl cyanoacetate (MCA). The molecular weight (Mw) of the model polymer was up to 50 500 g mol−1 with a high yield (99%). Eight AMCs were selected and a high-throughput parallel synthesizing instrument (HTPSI) was used to synthesize semi-library polymers of AMCs and EGDA via a Michael type polyaddition. The obtained AMC-based polymers had low cell cytotoxicity. Elastomers with cyanogen groups could be prepared using trimethylolpropane triacrylate (TMPTA) as a crosslinker. Furthermore, three dihalogen compounds were explored to polymerize with MCA and malononitrile via alkylation reactions. The pendent cyanogen or ester groups of the polymers could be reduced by lithium aluminum hydride. Novel polymer families were constructed based on the polyaddition and polyalkylation of AMCs.

Responsive polymers have significant importance and promising applications in the field of biomedicine. In this study, benzimidazole (BI)-based polyesters were synthesized for the first time via amine-ene click polycondensation. Benzimidazolethione (BITO) and aliphatic diacrylates (DA) were selected as clickable monomers using the organic catalyst 4-dimethylaminopyridine (DMAP) to obtain benzimidazole-based polyesters. 1,4-Butylene diacrylate (BDA) and poly(ethylene glycol) diacrylate (PEGDA) were used as model DA to synthesize lipophilic and hydrophilic polymers, respectively. Furthermore, click polymerization of BITO with BDA and PEGDA was conducted for tricomponent polycondensation. 1H NMR, FTIR and GPC spectra demonstrated that the BITO-based polyesters were successfully synthesized via the click condensation of amine-ene. The obtained polymers exhibited pH, reactive oxygen species (ROS) and β-cyclodextrin (β-CD) triple responsiveness and the amphiphilic BITO polyester can self-assemble into nanoparticles. We believe that these novel BITO polyesters have great potential as drug delivery systems for controlled drug release in nanomedicine.

Polymeric micelles (PMs) have been applied widely to transport hydrophobic drugs to tumor sites for cancer treatment. However, the low load efficiency of the drug in the PMs significantly reduces the therapeutic efficiency. We report here that disulfide-linked camptothecin (CPT) as a kind of dimeric drug can be effectively embedded in the core of poly(&epsilon, caprolactone)&ndash, poly(ethylene glycol)&ndash, poly(&epsilon, caprolactone) (PCL&ndash, PEG&ndash, PCL) PMs for improving drug-loading efficiency, and PEG can be used as a hydrophilic shell. Moreover, the dimeric CPT-loaded PCL&ndash, PCL PMs exhibited excellent solubility in phosphate-buffered saline (PBS) media and significant cytotoxicity to cancer cells.

Microfluidic chip electrophoresis (MCE) is a powerful separation tool for biomacromolecule analysis. However, adsorption of biomacromolecules, particularly proteins onto microfluidic channels severely degrades the separation performance of MCE. In this paper, an anti-protein-fouling MCE was fabricated using a novel sandwich photolithography of poly(ethylene glycol) (PEG) prepolymers. Photopatterned microchannel with a minimum resolution of 10 μm was achieved. After equipped with a conventional online electrochemical detector, the device enabled baseline separation of bovine serum albumin, lysozyme (Lys), and cytochrome c (Cyt-c) in 53 s under a voltage of 200 V. Compared with a traditional polydimethylsiloxane MCE made by soft lithography, the PEG MCE made by the sandwich photolithography not only eliminated the need of a master mold and the additional modification process of the microchannel but also showed excellent anti-protein-fouling properties for protein separation.