This review focuses on the attachment of polymer brushes to polymeric biomaterial substrates by chemical surface modification methods for biomedical applications. In the first part of this paper, a general introduction to the synthesis of polymer brushes is given. Thereafter, a comprehensive overview of recent work on the chemical surface modification of polymeric biomaterials, with a focus on "grafting-to," "grafting-from," and "grafting-through" strategies, is provided. Finally, some representative cutting-edge biomedical applications of modified polymeric biomaterials, mainly including antifouling materials and biocompatible materials, are highlighted. On the basis of this literature study, a perspective on future trends in this field is provided.

Chemical Surface Modification of Polymeric Biomaterials for Biomedical Applications.

Rationale:Inhibition of glycogen synthase kinase-3 (GSK-3) protects the heart during ischemia/reperfusion (I/R), yet the underlying mechanisms of cardioprotection afforded by beta isoform-specific inhibition GSK-3 remain to be elucidated. Objective:We studied the molecular mechanism mediating the effect of GSK-3β activation/inhibition upon myocardial injury during prolonged ischemia and I/R. Methods and Results:Beta isoform–specific inhibition of GSK-3 by dominant negative GSK-3β in transgenic mice (Tg-DnGSK-3β) or in heterozygous GSK-3β knock-out mice (GSK-3β+/−) significantly increased, whereas activation of GSK-3β in constitutively active GSK-3β knock-in mice (βKI) significantly decreased, myocardial ischemic injury after prolonged ischemia. In contrast, inhibition of GSK-3β in Tg-DnGSK-3β or GSK-3β+/− significantly reduced, while activation of GSK-3β in βKI significantly enhanced, myocardial I/R injury. Inhibition of GSK-3β stimulated mTOR signaling and inhibited autophagy through a rapamycin-sensitiv...

Differential Roles of GSK-3β During Myocardial Ischemia and Ischemia/Reperfusion

Here we report that negatively charged polysulfates can bind to the spike protein of SARS-CoV-2 via electrostatic interactions. Using a plaque reduction assay, we compare inhibition of SARS-CoV-2 by heparin, pentosan sulfate, linear polyglycerol sulfate (LPGS) and hyperbranched polyglycerol sulfate (HPGS). Highly sulfated LPGS is the optimal inhibitor, with a half-maximal inhibitory concentration (IC 50 ) of 67 µg/mL (approx. 1.6 µM). This synthetic polysulfate exhibits more than 60-fold higher virus inhibitory activity than heparin (IC 50 : 4084 µg/mL), along with much lower anticoagulant activity. Furthermore, in molecular dynamics simulations, we verified that LPGS can bind stronger to the spike protein than heparin, and that LPGS can interact even more with the spike protein of the new N501Y and E484K variants. Our study demonstrates that the entry of SARS-CoV-2 into host cells can be blocked via electrostatic interactions, therefore LPGS can serve as a blueprint for the design of novel viral inhibitors of SARS-CoV-2.

/pdf/polysulfates-block-sars-cov-2-uptake-through-electrostatic-1q2fo8d42s.pdf

Polysulfates Block SARS-CoV-2 Uptake through Electrostatic Interactions*.

Sulfated modification, characterization, and potential bioactivities of polysaccharide from the fruiting bodies of Russula virescens.

Self-Anticoagulant Nanocomposite Spheres for the Removal of Bilirubin from Whole Blood: A Step toward a Wearable Artificial Liver.

In vitro and in vivo anticoagulant activity of heparin-like biomacromolecules and the mechanism analysis for heparin-mimicking activity.

MicroRNAs (miRNAs) are important regulators in the process of cardiac hypertrophy and heart failure. Previous studies have shown that miR-199a is upregulated in pressure-overload cardiac hypertrophy and that inhibition of miR-199a attenuates cardiac hypertrophy in vitro. However, the therapeutic role of anti-miR-199a treatment in the cardiac hypertrophy in vivo model is less known. Here, we show an efficient and useful method to treat mouse cardiac hypertrophy and restore cardiac function through injection of adeno-associated virus (AAV)-mediated anti-miR-199a tough decoys (TuDs). RNA-seq transcriptome analysis indicated that genes related to cytoplasmic translation and mitochondrial respiratory chain complex assembly were upregulated in anti-miR-199a-treated recovered hearts. We further validated that PGC-1α is the direct target of miR-199a involved in the therapeutic effect and the regulation of the PGC-1α/ERRα axis and that the downstream pathway of mitochondrial fatty acid oxidation and oxidative phosphorylation constitute the underlying mechanism of the restored mitochondrial structure and function in our anti-miR-199a-treated mice. Our study highlights the important regulatory role of miR-199a in cardiac hypertrophy and the value of the AAV-mediated miRNA delivery system.

Adeno-associated virus-mediated delivery of anti-miR-199a tough decoys attenuates cardiac hypertrophy by targeting PGC-1alpha

We aimed to prepare a non‐invasive, reproducible, and controllable rat model of intracerebral hemorrhage with focused ultrasound (FUS).

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/ame2.12303

A new method for preparing a rat intracerebral hemorrhage model by combining focused ultrasound and microbubbles

https://doi.org/10.1016/j.pacs.2023.100499

Testicular torsion diagnosis and injury assessment using photoacoustic oxygenation imaging

Purpose To prepare nanoscale ultrasound contrast agents (Nano-UCAs) and examine the role of their surface charge in complement activation and phagocytosis. Materials and Methods We analyzed serum proteins present in the corona formed on Nano-UCAs and evaluated two important protein markers of complement activation (C3 and SC5b-9). The effect of surface charge on phagocytosis was further assessed using THP-1 macrophages. Results When Nano-UCAs were incubated with human serum, they were opsonized by various blood proteins, especially C3. Highly charged Nano-UCAs, whether positive or negative, were favorably opsonized by complement proteins and phagocytized by macrophages. Conclusion Charged Nano-UCAs show a higher tendency to activated complement system, and are efficiently engulfed by macrophages. The present results provide meaningful insights into the role of the surface charge of nanoparticles in the activation of the innate immune system, which is important not only for the design of targeted Nano-UCAs, but also for the effectiveness and safety of other theranostic agents.

https://www.dovepress.com/getfile.php?fileID=85888

Xiao-Xia Zhu

Papers

In vitro and in vivo anticoagulant activity of heparin-like biomacromolecules and the mechanism analysis for heparin-mimicking activity.

Adeno-associated virus-mediated delivery of anti-miR-199a tough decoys attenuates cardiac hypertrophy by targeting PGC-1alpha

A new method for preparing a rat intracerebral hemorrhage model by combining focused ultrasound and microbubbles

Testicular torsion diagnosis and injury assessment using photoacoustic oxygenation imaging

Role of Surface Charge of Nanoscale Ultrasound Contrast Agents in Complement Activation and Phagocytosis