A Mini Review of Advances in Porous Materials Designing for Hydrogen Isotope Separation.

The separation of mixtures of hydrogen isotopes is one of the greatest challenges of modern separation technology. A newly proposed separation mechanism, the quantum sieving (QS) effect, is expected to achieve high separation factors, the main desired properties for hydrogen isotope separation (HIS). Metal-organic frameworks (MOFs) and zeolites are excellent candidates to study these quantum effects because of their well-defined and tunable pore structure and the potential to introduce strong adsorption sites directly into the framework structure.

Integrating Liquification of the Gelated Tumor Interstitium around Nanomedicines with Biconditional GD2-Targeting for Precise and Safe Chemotherapy.

The quick diffusion of nanomedicines in the polysaccharide-gel-filling tumor interstitium and precise active targeting are two major obstacles that have not yet been overcome. Here, a poly(L-glutamyl-L-lysine(EK) (p(EK))-camouflaged, doxorubicin (Dox)-conjugated nanomedicine is developed to demonstrate the underlying mechanism of zwitterionic shell in synchronous barrier-penetration and biconditional active targeting. The zwitterionic p(EK) shell liquifies its surrounding water molecules in the polysaccharide gel of tumor interstitium, leading to five times faster diffusion than the pegylated Doxil with similar size in tumor tissue.

3D Interlayer Slidable Multilayer Nano-Graphene Oxide Acrylate Crosslinked Tough Hydrogel.

The design of three-dimensional crosslinked units with a spatial structure is of great significance for improving the mechanical properties of hydrogels. However, almost all the nanocomposites incorporated in hydrogels were defined as rigid nanofillers without further discussion on the potential contribution from the spatial structure change. In this work, the 3D nano chemical crosslinker multilayer graphene oxide acrylate (mGOa) was developed as a pressure-responsive crosslinker to achieve both low elastic modulus and high compression stress by synergizing more polymer chains against the loading force through interlayer sliding.

Spontaneously Restoring Specific Bioaffinity of RGD in Linear RGD-containing Peptides by Conjugation with Zwitterionic Dendrimers.

Peptides are more versatile than small molecule drugs, but their specific bioaffinities are usually lower than their original native proteins because of the loss of preferred conformations. To overcome this key obstacle, we demonstrated a hydrogen bond-induced conformational constraint method to enhance the specific bioaffinities of peptides to achieve a high success rate by using linear RGD-containing peptides as a model of bioactive peptides. By performing molecular simulation, we found that the chemically immobilized linear CRGDS via cysteine (C) at the N-terminus on zwitterionic PAMAM G-5 can not only spontaneously restore the natural conformation of the RGD segment through the assistance of the dynamic hydrogen bond from serine (S) at the C-terminus of the peptide, but it can also narrow the distribution of all possible conformations.

Development of Nonfouling Zwitterionic Copolymerized Peptides Based on Glutamic Acid and Lysine Dimers for Adjustable Enzymatic Degradation.

Nonspecific protein adsorption-resistant materials, the so-called nonfouling materials, are crucial biomaterials in biomedical applications. Up-to-date, little attention was paid to the biodegradability of these materials. In this work, nonfouling zwitterionic copolymerized peptides composed of the -l-glumatyl-l-lysine dimer (EK) and δ-l-lysinyl-l-glutamic acid dimer (E-K, glutamic acid with the lysine side chain) at various ratios were synthesized to investigate the enzymatic degradation rate.

Resistance to Long-Term Bacterial Biofilm Formation Based on Hydrolysis-Induced Zwitterion Material with Biodegradable and Self-Healing Properties.

Long-term resistance of biomaterials to the bacterial biofilm formation without antibiotic or biocide is highly demanded for biomedical applications. In this work, a novel biodegradable biomaterial with excellent capability to prevent long-term bacterial biofilm formation is prepared by the following two steps. Ethylcarboxybetaine ester analogue methacrylate (ECBEMA), poly(ethylene glycol) monomethacrylate (PEGMA), and 3-methacryloxypropyletris(trimethylsiloxy)silane (TRIS) were copolymerized to obtain p(ECBEMA-PEGMA-TRIS) (PEPT).

An electrospun polyurethane scaffold-reinforced zwitterionic hydrogel as a biocompatible device.

Although zwitterionic hydrogels exhibit excellent hemocompatibility, their extremely low tensile strength is an obstacle for their use in blood-contacting devices. Electrospun fiber scaffold-reinforced zwitterionic hydrogels are a possible solution to overcome the challenges of both mechanical strength and hemocompatibility. In this work, electrospun polyurethane (ePU) fiber scaffold-reinforced sulfobetaine methacrylate (SBMA) hydrogels (SRgels) were prepared.

Development of Zwitterionic Polypeptide Nanoformulation with High Doxorubicin Loading Content for Targeted Drug Delivery.

Much attention has been drawn to targeted nanodrug delivery systems due to their high therapeutic efficacy in cancer treatment. In this work, doxorubicin (DOX) was incorporated into a zwitterionic arginyl-glycyl-aspartic acid (RGD)-conjugated polypeptide by an emulsion solvent evaporation technique with high drug loading content (45%) and high drug loading efficiency (95%). This zwitterionic nanoformulation showed excellent colloidal stability at high dilution and in serum.

Development of ionic strength/pH/enzyme triple-responsive zwitterionic hydrogel of the mixed l-glutamic acid and l-lysine polypeptide for site-specific drug delivery.

Environmentally responsive hydrogels show enormous potential in various applications, such as tissue engineering and drug delivery. The site-specific controlled drug delivery of hydrogels can improve the therapeutic outcome and minimize the negative side effects. In this work, enzymatically digestible hydrogels, which are composed of equally mixed l-glutamic acid (E) and l-lysine (K) polypeptides after being crosslinked by the coupling reaction between carboxyl groups and primary amines catalyzed by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide·HCl (EDC·HCl), were prepared to improve the biocompatibility through reducing the nonspecific protein adsorption and cell attachment.

Development of polypeptide-based zwitterionic amphiphilic micelles for nanodrug delivery.

Protein molecules, which typically have a hydrophobic core and a zwitterionic shell with a polypeptide backbone, could be ideal materials for nanodrug vehicles (NDVs) with low side effects. Here, we synthesized poly(l-aspartic acid(lysine))-b-poly(l-lysine(Z)) (PAsp(Lys)-b-PLys(Z)) (PALLZ), a novel amphiphilic block polypeptide with key structures of protein to investigate the possibility for use as a NDV. This polypeptide can spontaneously self-assemble into micelles in aqueous solution with a zwitterionic brush (the PAsp(Lys) part) to provide the nonfouling shell and a hydrophobic core (the PLys(Z) part) for loading hydrophobic drugs.

[A case of Keutel syndrome in child (review the literature)].

Objective: The purpose is to report a calcification of the cartilaginous of the tracheobronchial case in child, and to recognize the clinical and imaging features on Keutel syndrome.

Method: A comprehensive analysis of the clinical data and X-ray,CT. Some literatures involving some symptoms of this child were reviewed.