Peptide-poly(ε-caprolactone) biohybrids by grafting-from ring-opening polymerization: Synthesis, aggregation, and crystalline properties

In Situ Preparation of Star-Shaped Protein-"Smart" Polymer Conjugates with pH and Thermo-Dual Responsibility for Bacterial Separation

To achieve effective separation and enrichment of bacteria, a novel synthetic scheme was developed to synthesize star-style boronate-functionalized copolymers with excellent hydrophilicity and temperature and pH responsiveness. A hydrophilic copolymer brush was synthesized by combining surface-initiated atom-transfer radical polymerization with amide reaction using bovine serum albumin as the core. The copolymer brush was further modified by introducing and immobilizing fluorophenylboronic acids through an amide reaction, resulting in the formation of boronate affinity material BSA@poly(NIPAm-co-AGE)@DFFPBA. The morphology and organic content of BSA@poly(NIPAm-co-AGE)@DFFPBA were systematically characterized. The BSA-derived composites demonstrated a strong binding capacity to both Gram-positive and Gram-negative bacteria. The binding capabilities of the affinity composite to Staphylococcus aureus and Salmonella spp. were 195.8 × 1010 CFU/g and 79.2 × 1010 CFU/g, respectively, which indicates that the novel composite exhibits a high binding capability to bacteria and shows a particularly more significant binding capacity toward Gram-positive bacteria. The bacterial binding of BSA@poly(NIPAm-co-AGE)@DFFPBA can be effectively altered by adjusting the pH and temperature. This study demonstrated that the star-shaped affinity composite had the potential to serve as an affinity material for the rapid separation and enrichment of bacteria in complex samples.

Straightforward synthesis of multifunctional porous polymer nanomaterials for CO2 capture and removal of contaminants

A straightforward synthesis of multifunctional mesoporous polymer nanomaterials suitable for the removal of contaminants and CO2 capture is reported.

Bioinspired Surface Functionalization for Improving Osteogenesis of Electrospun Polycaprolactone Nanofibers

Electrospun nanofibers, with a typical interconnected porous structure mimicking the extracellular matrix, are commonly used in bone tissue engineering. However, to the best of our knowledge, few studies have been reported to investigate the enhancement of osteogenesis capability of electrospun polycaprolactone (PCL) nanofibers based on bioinspired surface functionalization. In this study, a universal and versatile approach was proposed to spontaneously modify the electrospun PCL nanofibers with bioactive nano-hydroxyapatite (nHA), using dopamine as an effective bioadhesive agent. The evaluation of scanning electron microscopy, energy-dispersive spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and surface wettability indicated that nHA was successfully coated onto electrospun nanofibers (PCL-PDHA). Furthermore, in vitro cell experiment including adhesion, proliferation, and osteogenic capability and in vitro biomineralization test in simulated body fluid revealed that the PCL-PDHA nanofibers were biocompatible to MC3T3-E1 cells, and the osteogenesis and biomineralization capabilities were greatly improved in comparison with that of PCL nanofibers. In summary, the facile bioinspired surface functionalization method introduced in the present study, due to its universality and versatility, not only can be used to improve osteogenesis of electrospun nanofibers but also can be regarded as an avenue to achieve other predesigned purposes in biomedical engineering.

Fluorescent amphiphilic PEG-peptide-PEG triblock conjugate micelles for cell imaging

A fluorescent amphiphilic poly(ethylene glycol)-peptide-fluorophore-peptide-poly(ethylene glycol) (PEG-Pep-F-Pep-PEG) triblock conjugate with a hydrophobic fluorophore moiety at the centre of the chain is synthesized by "grafting to" technique based on Schiff-base coupling chemistry. The conjugate is characterized by nuclear magnetic resonance (NMR), circular dichroism (CD), and fluorescence spectroscopy techniques. The aqueous solution of the triblock conjugate emits blue light and exhibits a fluorescence emission band at 430 nm. The amphiphilic conjugate molecules undergo self-assembly into micelles (D ≈ 15-20 nm) in aqueous solution as confirmed from transmission electron microscopy (TEM) and dynamic light scattering (DLS). The critical aggregation concentration is determined by pyrene fluorescence assay and is found to be 0.051 mg mL(-1) . The highly stable and low toxic fluorescent PEG-Pep-F-Pep-PEG conjugate micelles are used for imaging of HeLa cells.