Functionalization of Covalent Organic Frameworks with Peptides by Polymer-Assisted Surface Modification and the Application for Protein Detection.

Although covalent organic frameworks (COFs) have received extensive attention for biomedical research due to their unique properties, their application is still hindered by the challenges of incorporating COFs with functional biomolecules. Since peptides have shown advantages in biomedical applications, herein, we propose the functionalization of COFs with peptides by a polymer-assisted surface modification strategy. Furthermore, a method based on the peptide-functionalized COFs for protein detection has also been developed to demonstrate their application potential. With the help of the polymers, peptides and horseradish peroxidase are attached onto COFs with a high surface density, and the developed method has achieved simple and sensitive detection of the secreted protein acidic and rich in cysteine. We speculate that the facile method proposed in this work to prepare peptide-functionalized COFs can not only benefit protein detection but also promote more biomedical applications of COFs.

Biodegradable zwitterionic polymer-cloaked defective metal-organic frameworks for ferroptosis-inducing cancer therapy.

Ferroptosis inhibits tumor growth by iron-dependently accumulating lipid peroxides (LPO) to a lethal extent, which can result from iron overload and glutathione peroxidase 4 (GPX4) inactivation. In this study, we developed biodegradable zwitterionic polymer-cloaked atorvastatin (ATV)-loaded ferric metal-organic frameworks (Fe-MOFs) for cancer treatment. Fe-MOFs served as nanoplatforms to co-deliver ferrous ions and ATV to cancer cells; the zwitterionic polymer membrane extended the circulation time of the nanoparticles and increased their accumulation at tumor sites. In cancer cells, the structure of the Fe-MOFs collapsed in the presence of glutathione (GSH), leading to the depletion of GSH and the release of ATV and Fe2+. The released ATV decreased mevalonate biosynthesis and GSH, resulting in GPX4 attenuation. A large number of reactive oxygen species were generated by the Fe2+-triggered Fenton reaction. This synergistic effect ultimately contributed to a lethal accumulation of LPO, causing cancer cell death. The findings both in vitro and in vivo suggested that this ferroptosis-inducing nanoplatform exhibited enhanced anticancer efficacy and preferable biocompatibility, which could provide a feasible strategy for anticancer therapy.

Case report:Multiple abscesses caused by Porphyromonas gingivalis diagnosed by metagenomic next-generation sequencing.

Background: Extraoral infection by Porphyromonas gingivalis (P. gingivalis) is extremely rare and challenging to diagnose because the fastidious pathogen is difficult to culture by traditional methods. We report the first case of a patient with multiple abscesses in muscles and the brain with dura empyema due to P. gingivalis, which was diagnosed by metagenomic next-generation sequencing (mNGS). Case presentation: A 65-year-old male patient was admitted to our hospital for multiple lumps in his body. Brain magnetic resonance imaging (MRI) and lower-limb computed tomography (CT) revealed multiple abscesses in the brain and muscles. A diagnosis of P. gingivalis infection was made based on mNGS tests of blood, cerebrospinal fluid (CSF), and pus samples, as the traditional bacterial culture of these samples showed negative results. Target antibiotic therapy with meropenem and metronidazole was administered, and CT-guided percutaneous catheter drainage of abscesses in both thighs was performed. The size of muscle abscesses reduced significantly and neurological function improved. The patient was followed up for 4 months. No abscesses re-appeared, and the remaining abscesses in his backside and both legs were completely absorbed. He can speak fluently and walk around freely without any neurological deficits. Conclusion: Metagenomic next-generation sequencing is helpful for early diagnosis and subsequent treatment of P. gingivalis-associated multiple abscesses.

Tough thermoplastic hydrogels with re-processability and recyclability for strain sensors.

Tough hydrogels with the ability to be repeatedly processed into various shapes as thermoplastics are highly desired in advanced medical devices and tissue engineering. Here, we have developed a kind of versatile supramolecular hydrogel with a network cross-linked by double hydrogen bonds from poly(N-acryloyl glycinamide) (PNAGA). The resulting PNAGA-30 hydrogels (30 wt% solid content) are tough, re-processable, and recyclable similar to thermoplastics. The hydrogels in the form of fragments can be easily re-processed into various shapes including sheet, filament, cylinder and other complex shapes by using simple stamping and injection methods. The mechanical properties of the re-programed hydrogels are comparable to the properties of the original hydrogels. The re-processability and robust mechanical properties of the PNAGA hydrogels are promising for practical applications in soft materials, tissue engineering and wearable devices. Furthermore, the PNAGA-30&LiCl ionic hydrogels can be fabricated by simply compositing LiCl into thermoplastic hydrogels. The PNAGA-30&LiCl hydrogels can function as multifunctional strain sensors to monitor large human movements and tiny vibrations, thereby showing great application potential in robotics, biomedical prosthetics, personal healthcare monitoring and so on.