Facile Preparation of Highly Stretchable and Recovery Peptide-Polyurethane/Ureas

In this work, a new class of highly stretchable peptide-polyurethane/ureas (PUUs) were synthesized containing short -sheet forming peptide blocks of poly(-benzyl-l-glutamate)-b-poly(propylene glycol)-b-poly(-benzyl-l-glutamate) (PBLG-b-PPG-b-PBLG), isophorone diisocyanate as the hard segment, and polytetramethylene ether glycol as the soft phase. PBLG-b-PPG-b-PBLG with short peptide segment length (1600%), human-tissue-compatible Young's modulus (226-513 KPa). Furthermore, the shape recovery ratio could reach above 85% during successive cycles at high strain (500%). In this study, we report a facile synthetic method to obtain highly stretchable and recovery peptide-polyurethane/urea materials, which will have various potential applications such as wearable and implantable electronics, and biomedical devices

Bioinspired poly(vinyl alcohol)-silk hybrids: Two-way water-sensitive shape-memory materials

Bioinspired poly(vinyl alcohol)-silk hybrids: Two-way water-sensitive shape-memory material

Synthesis and Properties of Shape Memory Poly(gamma-Benzyl-L-Glutamate)-b-Poly(Propylene Glycol)-b-Poly(gamma-Benzyl-L-Glutamate)

Shape memory polymers (SMPs) have attracted much attention as an important class of stimuli-responsive materials for biomedical applications. For SMP-based biomaterials, in addition to suitable shape recovery performances, their mechanical properties, biodegradability, biocompatibility, and sterilizability needs to be considered. Polypeptides can satisfy the requirements outlined above. However, there are few reports on shape memory polypeptides. In this paper, shape memory poly(gamma-benzyl-L-glutamate) (PBLG-PPG-PBLG) was synthesized by ring-opening polymerization of gamma-benzyl-L-glutamate-N-carboxyanhydrides (BLG-NCA) with poly(propylene glycol) bis(2-aminopropyl ether) as the macroinitiator. H-1 Nuclear Magnetic Resonance (NMR) and Fourier-Transform Infrared Spectroscopy (FTIR) were used to characterize the structure of the obtained PBLG-PPG-PBLG. The FTIR analysis showed that PBLG-PPG-PBLG has alpha-helical and beta-sheet structures. PBLG-PPG-PBLG has good shape memory properties, its shape recovery time is less than 120 s, and its shape recovery rate is 100%. In this study, we reported a simple synthetic method to obtain intelligent polypeptide materials, which will be used in many biomedical applications

Scalable Spider-Silk-Like Supertough Fibers using a Pseudoprotein Polymer

Scalable Spider-Silk-Like Supertough Fibers using a Pseudoprotein Polyme

Engineering magnetically induced antibacterial organic/inorganic hybrid nanoparticles for the treatment of periodontitis

The global age-standardized prevalence rate of severe periodontitis has already reached 13.1%, which makes it the second most common cause of tooth loss after caries, significantly reducing the quality of life for patients. Due to the complexity in the oral environment, it is practically difficult for conventional antibacterial materials to enter the periodontal pocket directly to eliminate periodontal plaque and inactivate target bacteria, such as Porphyromonas gingivalis (P. gingivalis). To solve this problem, this study proposes a type of antibacterial magnetic nanoparticles (named as AMPs) capable of anchoring polyhexamethylene biguanidine (PHMB) to treat periodontitis through magnetic induction-targeted fixation. According to the results of in vitro antibacterial experiments, AMPs could effectively remove bacterial biofilms by taking advantage of magnetic inductivity and the nanosize effect of nanoparticles, as well as the antibacterial effect of PHMB, with a clearance rate approaching 80%. More importantly, the in vivo experiments conducted on periodontitis demonstrated the disappearance of gingival redness and suppuration after AMPs treatment. As revealed by the quantitative analysis of microCT, different from the periodontitis groups, the growth of alveolar bone was recorded in the AMPs groups. In addition, HE staining confirmed histologically that the AMPs treatment group had an increase in the height of the alveolar ridge and bone mass but a reduction in the infiltration of inflammatory factors, which substantiated the therapeutic effect of AMPs on periodontitis. Therefore, the AMPs proposed in this study are expected to be widely applied as drug carriers intended for the treatment of periodontitis

Cadmium-Rich Plant Powder/PAN/PU Foams with Low Thermal Conductivity

Treating and utilizing heavy metal enriched plants have become growing problems. In this work, a series of composite foams were made from the powder of Cadmium-rich plant, polyacrylonitrile (PAN) and polyurethane (PU). Test results indicated that the addition of plant powder can not only increase the specific surface area, but also improve the apparent density and thermal stability of the foams. Besides, compared with the foam without plant powder, the powder-added foams exhibited a decreasing trend for thermal conductivity, and the minimum was 0.048 w/(m·k), which indicated that the addition of plant powder can help to enhance the thermal insulation of composite foam. More importantly, the results of leaching experiment showed that the leaching rate of heavy metal cadmium in the composite foam with 50% plant powder content was as low as 0.14% after being immersed in the acidic (pH = 3) solution for 5 days, which implies that the foam materials are very safe. This study provides a new way to realize high value-added resource utilization of heavy metal-enriched plants

Association between TLR4 and PTEN Involved in LPS-TLR4 Signaling Response

In this study, we explored the potential mechanisms of how PTEN regulating LPS induced TLR4 signaling pathway. The initial findings from ELISA demonstrate that PTEN influences TNF-α secretion by its lipid phosphatase activity. Subsequently, western blot, immunoprecipitation assay, and immunofluorescence were performed to explore the activation process of PTEN by stimulation with LPS. As early as 20 minutes after LPS stimulation, reduced phosphorylation of PTEN was found obviously. Accordingly, the whole cell-scattered PTEN translocated towards the cell membrane 20 minutes after stimulating with LPS. Moreover, the weak physical association between PTEN and TLR4 in resting RAW264.7 cells increased gradually after the stimulation of LPS. Furthermore, our study showed PTEN decreased LPS-induced Akt activity and upregulated NF-B-dependent gene transcription, identifying indirectly that the PTEN could regulate the activation of NF-B by its downstream Akt kinase. In summary, our study illustrates the potential signal transduction process of PTEN while stimulated by LPS: by increasing the association of TLR4, PTEN recruits to its phosphoinositide substrate PI(3,4,5)P3 located on the cell membrane and exerts its dephosphorylated function and subsequently depresses the activity of downstream molecule Akt and results in activation of NF-B, followed by the secretion of inflammatory mediators TNF-α.Peer Reviewe